diff --git a/CMakeLists.txt b/CMakeLists.txt
index fd08dcc2..835759e3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -74,12 +74,16 @@ if(ZINT_SANITIZE AND NOT MSVC)
             COMPILE_DEFINITIONS ${sanitizer_flag}
             LINK_OPTIONS ${sanitizer_flag}
         )
-        message (STATUS "Support for ${sanitizer_flag} available ... ${RESULT_VAR}")
+        message(STATUS "Support for ${sanitizer_flag} available ... ${RESULT_VAR}")
         if(RESULT_VAR)
             set(SANITIZER_FLAGS ${SANITIZER_FLAGS} ${sanitizer_flag})
         endif()
     endforeach()
     message(STATUS "Sanitizer flags: ${SANITIZER_FLAGS}")
+    if(NOT ZINT_DEBUG AND CMAKE_CXX_COMPILER_ID MATCHES "GNU")
+        # Gives warning on MainWindow::setupUI() and retries (& takes forever) if var-tracking-assignments enabled
+        add_compile_options(-fno-var-tracking-assignments)
+    endif()
 endif()
 
 if(APPLE)
diff --git a/backend/2of5.c b/backend/2of5.c
index 860b0ba8..4c8d5d60 100644
--- a/backend/2of5.c
+++ b/backend/2of5.c
@@ -33,6 +33,8 @@
 
 #include <stdio.h>
 #include "common.h"
+#include "gs1.h"
+
 #ifdef _MSC_VER
 #define inline _inline
 #endif
@@ -62,18 +64,6 @@ static inline char check_digit(const unsigned int count) {
     return itoc((10 - (count % 10)) % 10);
 }
 
-/* Calculate the check digit - the same method used for EAN-13 (GS1 General Specifications 7.9.1) */
-static unsigned int gs1_checksum(const unsigned char source[], const int length) {
-    int i;
-    unsigned int count = 0;
-    int factor = length & 1 ? 3 : 1;
-    for (i = 0; i < length; i++) {
-        count += factor * ctoi(source[i]);
-        factor = factor == 1 ? 3 : 1;
-    }
-    return count;
-}
-
 /* Common to Standard (Matrix), Industrial, IATA, and Data Logic */
 static int c25_common(struct zint_symbol *symbol, const unsigned char source[], int length, const int max,
             const char *table[10], const char *start_stop[2], const int error_base) {
@@ -97,7 +87,7 @@ static int c25_common(struct zint_symbol *symbol, const unsigned char source[],
 
     if (have_checkdigit) {
         /* Add standard GS1 check digit */
-        temp[length] = check_digit(gs1_checksum(source, length));
+        temp[length] = gs1_check_digit(source, length);
         temp[++length] = '\0';
     }
 
@@ -173,7 +163,7 @@ static int c25inter_common(struct zint_symbol *symbol, unsigned char source[], i
 
     if (have_checkdigit) {
         /* Add standard GS1 check digit */
-        temp[length] = check_digit(gs1_checksum(temp, length));
+        temp[length] = gs1_check_digit(temp, length);
         temp[++length] = '\0';
     }
 
@@ -258,7 +248,7 @@ INTERNAL int itf14(struct zint_symbol *symbol, unsigned char source[], int lengt
     ustrcpy(localstr + zeroes, source);
 
     /* Calculate the check digit - the same method used for EAN-13 */
-    localstr[13] = check_digit(gs1_checksum(localstr, 13));
+    localstr[13] = gs1_check_digit(localstr, 13);
     localstr[14] = '\0';
     error_number = c25inter_common(symbol, localstr, 14, 1 /*dont_set_height*/);
     ustrcpy(symbol->text, localstr);
diff --git a/backend/code.c b/backend/code.c
index 3f764f89..d84d6d79 100644
--- a/backend/code.c
+++ b/backend/code.c
@@ -111,17 +111,17 @@ INTERNAL int code_11(struct zint_symbol *symbol, unsigned char source[], int len
     assert(length > 0);
 
     if (length > 121) {
-        strcpy(symbol->errtxt, "320: Input too long");
+        strcpy(symbol->errtxt, "320: Input too long (121 character maximum)");
         return ZINT_ERROR_TOO_LONG;
     }
     error_number = is_sane(SODIUM, source, length);
     if (error_number == ZINT_ERROR_INVALID_DATA) {
-        strcpy(symbol->errtxt, "321: Invalid characters in data");
+        sprintf(symbol->errtxt, "321: Invalid characters in data (\"%s\" only)", SODIUM);
         return error_number;
     }
 
     if (symbol->option_2 < 0 || symbol->option_2 > 2) {
-        strcpy(symbol->errtxt, "339: Invalid check digit version");
+        strcpy(symbol->errtxt, "339: Invalid check digit version (1, 2 only)");
         return ZINT_ERROR_INVALID_OPTION;
     }
     if (symbol->option_2 == 2) {
@@ -230,20 +230,21 @@ INTERNAL int c39(struct zint_symbol *symbol, unsigned char source[], int length)
     }
 
     if ((symbol->symbology == BARCODE_LOGMARS) && (length > 30)) { /* MIL-STD-1189 Rev. B Section 5.2.6.2 */
-        strcpy(symbol->errtxt, "322: Input too long");
+        strcpy(symbol->errtxt, "322: Input too long (30 character maximum)");
         return ZINT_ERROR_TOO_LONG;
     /* Prevent encoded_data out-of-bounds >= 143 for BARCODE_HIBC_39 due to wider 'wide' bars */
     } else if ((symbol->symbology == BARCODE_HIBC_39) && (length > 68)) {
-        strcpy(symbol->errtxt, "319: Input too long"); /* Note use 319 (2of5 range) as 340 taken by CODE128 */
+        /* Note use 319 (2of5 range) as 340 taken by CODE128 */
+        strcpy(symbol->errtxt, "319: Input too long (68 character maximum)");
         return ZINT_ERROR_TOO_LONG;
     } else if (length > 85) {
-        strcpy(symbol->errtxt, "323: Input too long");
+        strcpy(symbol->errtxt, "323: Input too long (85 character maximum)");
         return ZINT_ERROR_TOO_LONG;
     }
     to_upper(source);
     error_number = is_sane(SILVER, source, length);
     if (error_number == ZINT_ERROR_INVALID_DATA) {
-        strcpy(symbol->errtxt, "324: Invalid characters in data");
+        strcpy(symbol->errtxt, "324: Invalid characters in data (alphanumerics and \"-. $/+%\" only)");
         return error_number;
     }
 
@@ -356,12 +357,12 @@ INTERNAL int pharmazentral(struct zint_symbol *symbol, unsigned char source[], i
     char localstr[11];
 
     if (length > 7) {
-        strcpy(symbol->errtxt, "325: Input wrong length");
+        strcpy(symbol->errtxt, "325: Input wrong length (7 character maximum)");
         return ZINT_ERROR_TOO_LONG;
     }
     error_number = is_sane(NEON, source, length);
     if (error_number == ZINT_ERROR_INVALID_DATA) {
-        strcpy(symbol->errtxt, "326: Invalid characters in data");
+        strcpy(symbol->errtxt, "326: Invalid characters in data (digits only)");
         return error_number;
     }
 
@@ -383,7 +384,7 @@ INTERNAL int pharmazentral(struct zint_symbol *symbol, unsigned char source[], i
     }
 
     if (check_digit == 10) {
-        strcpy(symbol->errtxt, "327: Invalid PZN Data");
+        strcpy(symbol->errtxt, "327: Invalid PZN, check digit is '10'");
         return ZINT_ERROR_INVALID_DATA;
     }
     localstr[8] = itoc(check_digit);
@@ -417,7 +418,7 @@ INTERNAL int ec39(struct zint_symbol *symbol, unsigned char source[], int length
     int error_number;
 
     if (length > 85) {
-        strcpy(symbol->errtxt, "328: Input too long");
+        strcpy(symbol->errtxt, "328: Input too long (85 character maximum)");
         return ZINT_ERROR_TOO_LONG;
     }
 
@@ -425,7 +426,7 @@ INTERNAL int ec39(struct zint_symbol *symbol, unsigned char source[], int length
     for (i = 0; i < length; i++) {
         if (source[i] > 127) {
             /* Cannot encode extended ASCII */
-            strcpy(symbol->errtxt, "329: Invalid characters in input data");
+            strcpy(symbol->errtxt, "329: Invalid characters in data, extended ASCII not allowed");
             return ZINT_ERROR_INVALID_DATA;
         }
         ustrcat(buffer, EC39Ctrl[source[i]]);
@@ -458,7 +459,7 @@ INTERNAL int c93(struct zint_symbol *symbol, unsigned char source[], int length)
     strcpy(buffer, "");
 
     if (length > 107) {
-        strcpy(symbol->errtxt, "330: Input too long");
+        strcpy(symbol->errtxt, "330: Input too long (107 character maximum)");
         return ZINT_ERROR_TOO_LONG;
     }
 
@@ -466,7 +467,7 @@ INTERNAL int c93(struct zint_symbol *symbol, unsigned char source[], int length)
     for (i = 0; i < length; i++) {
         if (source[i] > 127) {
             /* Cannot encode extended ASCII */
-            strcpy(symbol->errtxt, "331: Invalid characters in input data");
+            strcpy(symbol->errtxt, "331: Invalid characters in data, extended ASCII not allowed");
             return ZINT_ERROR_INVALID_DATA;
         }
         strcat(buffer, C93Ctrl[source[i]]);
@@ -476,7 +477,7 @@ INTERNAL int c93(struct zint_symbol *symbol, unsigned char source[], int length)
     /* Now we can check the true length of the barcode */
     h = (int) strlen(buffer);
     if (h > 107) {
-        strcpy(symbol->errtxt, "332: Input too long");
+        strcpy(symbol->errtxt, "332: Input too long"); // TODO: Better error message
         return ZINT_ERROR_TOO_LONG;
     }
 
@@ -674,21 +675,22 @@ nb0:    if (++B[0] <= bmax[0]) goto lb0;
 
 /* Channel Code - According to ANSI/AIM BC12-1998 */
 INTERNAL int channel_code(struct zint_symbol *symbol, unsigned char source[], int length) {
+    static int max_ranges[] = { -1, -1, -1, 26, 292, 3493, 44072, 576688, 7742862 };
     int S[8] = {0}, B[8] = {0};
     long target_value = 0;
     char pattern[30];
     int channels, i;
-    int error_number, range = 0, zeroes;
+    int error_number, zeroes;
     char hrt[9];
     float height;
 
     if (length > 7) {
-        strcpy(symbol->errtxt, "333: Input too long");
+        strcpy(symbol->errtxt, "333: Input too long (7 character maximum)");
         return ZINT_ERROR_TOO_LONG;
     }
     error_number = is_sane(NEON, source, length);
     if (error_number == ZINT_ERROR_INVALID_DATA) {
-        strcpy(symbol->errtxt, "334: Invalid characters in data");
+        strcpy(symbol->errtxt, "334: Invalid characters in data (digits only)");
         return error_number;
     }
 
@@ -721,34 +723,8 @@ INTERNAL int channel_code(struct zint_symbol *symbol, unsigned char source[], in
         channels = 3;
     }
 
-    switch (channels) {
-        case 3: if (target_value > 26) {
-                range = 1;
-            }
-            break;
-        case 4: if (target_value > 292) {
-                range = 1;
-            }
-            break;
-        case 5: if (target_value > 3493) {
-                range = 1;
-            }
-            break;
-        case 6: if (target_value > 44072) {
-                range = 1;
-            }
-            break;
-        case 7: if (target_value > 576688) {
-                range = 1;
-            }
-            break;
-        case 8: if (target_value > 7742862) {
-                range = 1;
-            }
-            break;
-    }
-    if (range) {
-        strcpy(symbol->errtxt, "335: Value out of range");
+    if (target_value > max_ranges[channels]) {
+        sprintf(symbol->errtxt, "335: Value out of range (0 to %d) for %d channels", max_ranges[channels], channels);
         return ZINT_ERROR_INVALID_DATA;
     }
 
@@ -804,13 +780,13 @@ INTERNAL int vin(struct zint_symbol *symbol, unsigned char source[], int length)
 
     // Check length
     if (length != 17) {
-        strcpy(symbol->errtxt, "336: Input wrong length, 17 characters required");
+        strcpy(symbol->errtxt, "336: Input wrong length (17 characters required)");
         return ZINT_ERROR_TOO_LONG;
     }
 
     // Check input characters, I, O and Q are not allowed
     if (is_sane(ARSENIC, source, length) == ZINT_ERROR_INVALID_DATA) {
-        strcpy(symbol->errtxt, "337: Invalid characters in input data");
+        sprintf(symbol->errtxt, "337: Invalid characters in data (\"%s\" only)", ARSENIC);
         return ZINT_ERROR_INVALID_DATA;
     }
 
@@ -852,8 +828,8 @@ INTERNAL int vin(struct zint_symbol *symbol, unsigned char source[], int length)
         }
 
         if (input_check != output_check) {
-            strcpy(symbol->errtxt, "338: Invalid check digit in input data");
-            return ZINT_ERROR_INVALID_DATA;
+            sprintf(symbol->errtxt, "338: Invalid check digit '%c', expecting '%c'", input_check, output_check);
+            return ZINT_ERROR_INVALID_CHECK;
         }
     }
 
diff --git a/backend/dmatrix.c b/backend/dmatrix.c
index 413913fa..c2f5880f 100644
--- a/backend/dmatrix.c
+++ b/backend/dmatrix.c
@@ -269,7 +269,7 @@ static int p_r_6_2_1(const unsigned char inputData[], const int position, const
 
 /* 'look ahead test' from Annex P */
 static int look_ahead_test(const unsigned char inputData[], const int sourcelen, const int position,
-            const int current_mode, const int gs1) {
+            const int current_mode, const int gs1, const int debug) {
     float ascii_count, c40_count, text_count, x12_count, edf_count, b256_count;
     int ascii_rnded, c40_rnded, text_rnded, x12_rnded, edf_rnded, b256_rnded;
     float cnt_1;
@@ -379,6 +379,12 @@ static int look_ahead_test(const unsigned char inputData[], const int sourcelen,
             text_count = stripf(text_count);
             x12_count = stripf(x12_count);
             c40_count = stripf(c40_count);
+            if (debug) {
+                printf("\n(%d, %d, %d): ascii_count %.8g, b256_count %.8g, edf_count %.8g, text_count %.8g"
+                        ", x12_count %.8g, c40_count %.8g",
+                        current_mode, position, sp, ascii_count, b256_count, edf_count, text_count,
+                        x12_count, c40_count);
+            }
 
             cnt_1 = ascii_count + 1.0f;
             if (cnt_1 <= b256_count && cnt_1 <= edf_count && cnt_1 <= text_count && cnt_1 <= x12_count
@@ -428,6 +434,12 @@ static int look_ahead_test(const unsigned char inputData[], const int sourcelen,
     text_rnded = (int) ceilf(stripf(text_count));
     x12_rnded = (int) ceilf(stripf(x12_count));
     c40_rnded = (int) ceilf(stripf(c40_count));
+    if (debug) {
+        printf("\nEOD(%d, %d): ascii_rnded %d, b256_rnded %d, edf_rnded %d, text_rnded %d, x12_rnded %d (%g)"
+                ", c40_rnded %d (%g)\n",
+                current_mode, position, ascii_rnded, b256_rnded, edf_rnded, text_rnded, x12_rnded, x12_count,
+                c40_rnded, c40_count);
+    }
 
     if (ascii_rnded <= b256_rnded && ascii_rnded <= edf_rnded && ascii_rnded <= text_rnded && ascii_rnded <= x12_rnded
             && ascii_rnded <= c40_rnded) {
@@ -695,7 +707,7 @@ static int dm200encode(struct zint_symbol *symbol, const unsigned char source[],
                 tp++;
                 sp += 2;
             } else {
-                next_mode = look_ahead_test(source, inputlen, sp, current_mode, gs1);
+                next_mode = look_ahead_test(source, inputlen, sp, current_mode, gs1, debug);
 
                 if (next_mode != DM_ASCII) {
                     switch (next_mode) {
@@ -753,7 +765,7 @@ static int dm200encode(struct zint_symbol *symbol, const unsigned char source[],
 
             next_mode = current_mode;
             if (process_p == 0) {
-                next_mode = look_ahead_test(source, inputlen, sp, current_mode, gs1);
+                next_mode = look_ahead_test(source, inputlen, sp, current_mode, gs1, debug);
             }
 
             if (next_mode != current_mode) {
@@ -809,7 +821,7 @@ static int dm200encode(struct zint_symbol *symbol, const unsigned char source[],
 
             next_mode = DM_X12;
             if (process_p == 0) {
-                next_mode = look_ahead_test(source, inputlen, sp, current_mode, gs1);
+                next_mode = look_ahead_test(source, inputlen, sp, current_mode, gs1, debug);
             }
 
             if (next_mode != DM_X12) {
@@ -844,7 +856,7 @@ static int dm200encode(struct zint_symbol *symbol, const unsigned char source[],
             if (process_p == 3) {
                 /* Note different then spec Step (f)(1), which suggests checking when 0, but this seems to work
                    better in many cases. */
-                next_mode = look_ahead_test(source, inputlen, sp, current_mode, gs1);
+                next_mode = look_ahead_test(source, inputlen, sp, current_mode, gs1, debug);
             }
 
             if (next_mode != DM_EDIFACT) {
@@ -868,7 +880,7 @@ static int dm200encode(struct zint_symbol *symbol, const unsigned char source[],
 
         /* step (g) Base 256 encodation */
         } else if (current_mode == DM_BASE256) {
-            next_mode = look_ahead_test(source, inputlen, sp, current_mode, gs1);
+            next_mode = look_ahead_test(source, inputlen, sp, current_mode, gs1, debug);
 
             if (next_mode == DM_BASE256) {
                 target[tp] = source[sp];
diff --git a/backend/gs1.c b/backend/gs1.c
index 1fadecdf..5e98b823 100644
--- a/backend/gs1.c
+++ b/backend/gs1.c
@@ -1386,3 +1386,17 @@ INTERNAL int gs1_verify(struct zint_symbol *symbol, const unsigned char source[]
     /* the character '[' in the reduced string refers to the FNC1 character */
     return error_value;
 }
+
+/* Helper to return standard GS1 check digit (GS1 General Specifications 7.9.1) */
+INTERNAL char gs1_check_digit(const unsigned char source[], const int length) {
+    int i;
+    int count = 0;
+    int factor = length & 1 ? 3 : 1;
+
+    for (i = 0; i < length; i++) {
+        count += factor * ctoi(source[i]);
+        factor = factor == 1 ? 3 : 1;
+    }
+
+    return itoc((10 - (count % 10)) % 10);
+}
diff --git a/backend/gs1.h b/backend/gs1.h
index db96f722..d7f2c658 100644
--- a/backend/gs1.h
+++ b/backend/gs1.h
@@ -39,6 +39,7 @@ extern "C" {
 
 INTERNAL int gs1_verify(struct zint_symbol *symbol, const unsigned char source[], const int src_len,
                 unsigned char reduced[]);
+INTERNAL char gs1_check_digit(const unsigned char source[], const int src_len);
 
 #ifdef __cplusplus
 }
diff --git a/backend/library.c b/backend/library.c
index e356a099..a39bf5fa 100644
--- a/backend/library.c
+++ b/backend/library.c
@@ -1286,33 +1286,18 @@ int ZBarcode_Print(struct zint_symbol *symbol, int rotate_angle) {
         to_upper((unsigned char *) output);
 
         if (!(strcmp(output, "PNG"))) {
-            if (symbol->scale < 1.0f) {
-                symbol->text[0] = '\0';
-            }
             error_number = plot_raster(symbol, rotate_angle, OUT_PNG_FILE);
 
         } else if (!(strcmp(output, "BMP"))) {
-            if (symbol->scale < 1.0f) {
-                symbol->text[0] = '\0';
-            }
             error_number = plot_raster(symbol, rotate_angle, OUT_BMP_FILE);
 
         } else if (!(strcmp(output, "PCX"))) {
-            if (symbol->scale < 1.0f) {
-                symbol->text[0] = '\0';
-            }
             error_number = plot_raster(symbol, rotate_angle, OUT_PCX_FILE);
 
         } else if (!(strcmp(output, "GIF"))) {
-            if (symbol->scale < 1.0f) {
-                symbol->text[0] = '\0';
-            }
             error_number = plot_raster(symbol, rotate_angle, OUT_GIF_FILE);
 
         } else if (!(strcmp(output, "TIF"))) {
-            if (symbol->scale < 1.0f) {
-                symbol->text[0] = '\0';
-            }
             error_number = plot_raster(symbol, rotate_angle, OUT_TIF_FILE);
 
         } else if (!(strcmp(output, "TXT"))) {
@@ -1522,7 +1507,7 @@ int ZBarcode_Encode_File(struct zint_symbol *symbol, char *filename) {
     if (file_opened) {
         fclose(file);
     }
-    ret = ZBarcode_Encode(symbol, buffer, nRead);
+    ret = ZBarcode_Encode(symbol, buffer, (int) nRead);
     free(buffer);
     return ret;
 }
diff --git a/backend/output.h b/backend/output.h
index 25d66e10..8a626b13 100644
--- a/backend/output.h
+++ b/backend/output.h
@@ -44,8 +44,8 @@ INTERNAL int output_process_upcean(struct zint_symbol *symbol, int *p_main_width
                 unsigned char addon[6], int *p_addon_gap);
 INTERNAL float output_large_bar_height(struct zint_symbol *symbol, int si);
 INTERNAL void output_upcean_split_text(int upceanflag, unsigned char text[],
-                unsigned char textpart1[], unsigned char textpart2[], unsigned char textpart3[],
-                unsigned char textpart4[]);
+                unsigned char textpart1[5], unsigned char textpart2[7], unsigned char textpart3[7],
+                unsigned char textpart4[2]);
 
 #ifdef __cplusplus
 }
diff --git a/backend/rss.c b/backend/rss.c
index b25dc316..8ea2cb4a 100644
--- a/backend/rss.c
+++ b/backend/rss.c
@@ -31,7 +31,7 @@
  */
 /* vim: set ts=4 sw=4 et : */
 
-/* The functions "combins" and "getRSSwidths" are copyright BSI and are
+/* The functions "rss_combins" and "getRSSwidths" are copyright BSI and are
    released with permission under the following terms:
 
    "Copyright subsists in all BSI publications. BSI also holds the copyright, in the
@@ -73,11 +73,11 @@
 #include "gs1.h"
 #include "general_field.h"
 
-/**********************************************************************
- * combins(n,r): returns the number of Combinations of r selected from n:
+/****************************************************************************
+ * rss_combins(n,r): returns the number of Combinations of r selected from n:
  *   Combinations = n! / ((n - r)! * r!)
- **********************************************************************/
-static int combins(const int n, const int r) {
+ ****************************************************************************/
+static int rss_combins(const int n, const int r) {
     int i, j;
     int maxDenom, minDenom;
     int val;
@@ -128,11 +128,11 @@ static void getRSSwidths(int widths[], int val, int n, const int elements, const
                 ;
                 elmWidth++, narrowMask &= ~(1 << bar)) {
             /* get all combinations */
-            subVal = combins(n - elmWidth - 1, elements - bar - 2);
+            subVal = rss_combins(n - elmWidth - 1, elements - bar - 2);
             /* less combinations with no single-module element */
-            if ((!noNarrow) && (!narrowMask) &&
-                    (n - elmWidth - (elements - bar - 1) >= elements - bar - 1)) {
-                subVal -= combins(n - elmWidth - (elements - bar), elements - bar - 2);
+            if ((!noNarrow) && (!narrowMask)
+                    && (n - elmWidth - (elements - bar - 1) >= elements - bar - 1)) {
+                subVal -= rss_combins(n - elmWidth - (elements - bar), elements - bar - 2);
             }
             /* less combinations with elements > maxVal */
             if (elements - bar - 1 > 1) {
@@ -140,7 +140,7 @@ static void getRSSwidths(int widths[], int val, int n, const int elements, const
                 for (mxwElement = n - elmWidth - (elements - bar - 2);
                         mxwElement > maxWidth;
                         mxwElement--) {
-                    lessVal += combins(n - elmWidth - mxwElement - 1, elements - bar - 3);
+                    lessVal += rss_combins(n - elmWidth - mxwElement - 1, elements - bar - 3);
                 }
                 subVal -= lessVal * (elements - 1 - bar);
             } else if (n - elmWidth > maxWidth) {
@@ -157,24 +157,8 @@ static void getRSSwidths(int widths[], int val, int n, const int elements, const
     return;
 }
 
-/* Calculate check digit from Annex A */
-static int calc_check_digit(const unsigned char *src) {
-    int i, check_digit;
-    int count = 0;
-
-    for (i = 0; i < 13; i++) {
-        count += (i & 1) ? ctoi(src[i]) : 3 * ctoi(src[i]);
-    }
-    check_digit = 10 - (count % 10);
-    if (check_digit == 10) {
-        check_digit = 0;
-    }
-
-    return check_digit;
-}
-
 /* Set GTIN-14 human readable text */
-static void set_gtin14_hrt(struct zint_symbol *symbol, const unsigned char *source, const int src_len) {
+static void rss_set_gtin14_hrt(struct zint_symbol *symbol, const unsigned char *source, const int src_len) {
     int i;
     unsigned char hrt[15];
 
@@ -186,7 +170,7 @@ static void set_gtin14_hrt(struct zint_symbol *symbol, const unsigned char *sour
         hrt[12 - i] = source[src_len - i - 1];
     }
 
-    hrt[13] = itoc(calc_check_digit(hrt));
+    hrt[13] = gs1_check_digit(hrt, 13);
     hrt[14] = '\0';
 
     ustrcat(symbol->text, hrt);
@@ -319,18 +303,19 @@ INTERNAL int rss14_cc(struct zint_symbol *symbol, unsigned char source[], int sr
     separator_row = 0;
 
     if (src_len > 14) { /* Allow check digit to be specified (will be verified and ignored) */
-        strcpy(symbol->errtxt, "380: Input too long");
+        strcpy(symbol->errtxt, "380: Input too long (14 character maximum)");
         return ZINT_ERROR_TOO_LONG;
     }
     error_number = is_sane(NEON, source, src_len);
     if (error_number == ZINT_ERROR_INVALID_DATA) {
-        strcpy(symbol->errtxt, "381: Invalid characters in data");
+        strcpy(symbol->errtxt, "381: Invalid characters in data (digits only)");
         return error_number;
     }
 
     if (src_len == 14) { /* Verify check digit */
-        if (calc_check_digit(source) != ctoi(source[13])) {
-            strcpy(symbol->errtxt, "388: Invalid check digit");
+        if (gs1_check_digit(source, 13) != source[13]) {
+            sprintf(symbol->errtxt, "388: Invalid check digit '%c', expecting '%c'",
+                    source[13], gs1_check_digit(source, 13));
             return ZINT_ERROR_INVALID_CHECK;
         }
         src_len--; /* Ignore */
@@ -422,7 +407,6 @@ INTERNAL int rss14_cc(struct zint_symbol *symbol, unsigned char source[], int sr
     v_odd[2] = (data_character[2] - g_sum_table[data_group[2]]) / t_table[data_group[2]];
     v_even[2] = (data_character[2] - g_sum_table[data_group[2]]) % t_table[data_group[2]];
 
-
     /* Use RSS subset width algorithm */
     for (i = 0; i < 4; i++) {
         if ((i == 0) || (i == 2)) {
@@ -450,7 +434,6 @@ INTERNAL int rss14_cc(struct zint_symbol *symbol, unsigned char source[], int sr
         }
     }
 
-
     checksum = 0;
     /* Calculate the checksum */
     for (i = 0; i < 8; i++) {
@@ -508,7 +491,7 @@ INTERNAL int rss14_cc(struct zint_symbol *symbol, unsigned char source[], int sr
         symbol->rows = symbol->rows + 1;
 
         /* Set human readable text */
-        set_gtin14_hrt(symbol, source, src_len);
+        rss_set_gtin14_hrt(symbol, source, src_len);
 
 #ifdef COMPLIANT_HEIGHTS
         /* Minimum height is 13X for truncated symbol ISO/IEC 24724:2011 5.3.1
@@ -658,18 +641,19 @@ INTERNAL int rsslimited_cc(struct zint_symbol *symbol, unsigned char source[], i
     separator_row = 0;
 
     if (src_len > 14) { /* Allow check digit to be specified (will be verified and ignored) */
-        strcpy(symbol->errtxt, "382: Input too long");
+        strcpy(symbol->errtxt, "382: Input too long (14 character maximum)");
         return ZINT_ERROR_TOO_LONG;
     }
     error_number = is_sane(NEON, source, src_len);
     if (error_number == ZINT_ERROR_INVALID_DATA) {
-        strcpy(symbol->errtxt, "383: Invalid characters in data");
+        strcpy(symbol->errtxt, "383: Invalid characters in data (digits only)");
         return error_number;
     }
 
     if (src_len == 14) { /* Verify check digit */
-        if (calc_check_digit(source) != ctoi(source[13])) {
-            strcpy(symbol->errtxt, "389: Invalid check digit");
+        if (gs1_check_digit(source, 13) != source[13]) {
+            sprintf(symbol->errtxt, "389: Invalid check digit '%c', expecting '%c'",
+                    source[13], gs1_check_digit(source, 13));
             return ZINT_ERROR_INVALID_CHECK;
         }
         src_len--; /* Ignore */
@@ -677,7 +661,7 @@ INTERNAL int rsslimited_cc(struct zint_symbol *symbol, unsigned char source[], i
 
     if (src_len == 13) {
         if ((source[0] != '0') && (source[0] != '1')) {
-            strcpy(symbol->errtxt, "384: Input out of range");
+            strcpy(symbol->errtxt, "384: Input out of range (0 to 1999999999999)");
             return ZINT_ERROR_INVALID_DATA;
         }
     }
@@ -810,7 +794,7 @@ INTERNAL int rsslimited_cc(struct zint_symbol *symbol, unsigned char source[], i
     }
 
     /* Set human readable text */
-    set_gtin14_hrt(symbol, source, src_len);
+    rss_set_gtin14_hrt(symbol, source, src_len);
 
     /* ISO/IEC 24724:2011 6.2 10X minimum height, use as default also */
     if (symbol->symbology == BARCODE_DBAR_LTD_CC) {
@@ -846,11 +830,11 @@ INTERNAL int rss_date(const unsigned char source[], const int src_posn) {
 }
 
 /* Handles all data encodation from section 7.2.5 of ISO/IEC 24724 */
-static int rss_binary_string(struct zint_symbol *symbol, const unsigned char source[], char binary_string[],
-            int *p_bp) {
+static int rssexp_binary_string(struct zint_symbol *symbol, const unsigned char source[], char binary_string[],
+            int cols_per_row, int *p_bp) {
     int encoding_method, i, j, read_posn, debug = (symbol->debug & ZINT_DEBUG_PRINT), mode = NUMERIC;
     char last_digit = '\0';
-    int symbol_characters, characters_per_row;
+    int symbol_characters, characters_per_row = cols_per_row * 2;
     int length = (int) ustrlen(source);
 #ifndef _MSC_VER
     char general_field[length + 1];
@@ -897,9 +881,9 @@ static int rss_binary_string(struct zint_symbol *symbol, const unsigned char sou
                         encoding_method = 7;
                     }
 
-                } else if ((length == 34) && (source[26] == '1') &&
-                        (source[27] == '1' || source[27] == '3' || source[27] == '5' || source[27] == '7') &&
-                        rss_date(source, 28) >= 0) {
+                } else if ((length == 34) && (source[26] == '1')
+                            && (source[27] == '1' || source[27] == '3' || source[27] == '5' || source[27] == '7')
+                            && rss_date(source, 28) >= 0) {
 
                     /* (01), (310x) and (11) - metric weight and production date */
                     /* (01), (310x) and (13) - metric weight and packaging date */
@@ -928,9 +912,9 @@ static int rss_binary_string(struct zint_symbol *symbol, const unsigned char sou
                         encoding_method = 8;
                     }
 
-                } else if ((length == 34) && (source[26] == '1') &&
-                        (source[27] == '1' || source[27] == '3' || source[27] == '5' || source[27] == '7') &&
-                        rss_date(source, 28) >= 0) {
+                } else if ((length == 34) && (source[26] == '1')
+                            && (source[27] == '1' || source[27] == '3' || source[27] == '5' || source[27] == '7')
+                            && rss_date(source, 28) >= 0) {
 
                     /* (01), (320x) and (11) - English weight and production date */
                     /* (01), (320x) and (13) - English weight and packaging date */
@@ -988,7 +972,7 @@ static int rss_binary_string(struct zint_symbol *symbol, const unsigned char sou
         if ((source[i] < '0') || (source[i] > '9')) {
             if (source[i] != '[') {
                 /* Something is wrong */
-                strcpy(symbol->errtxt, "385: Invalid characters in input data");
+                strcpy(symbol->errtxt, "385: Invalid characters in input data"); // TODO: Better error message
                 return ZINT_ERROR_INVALID_DATA;
             }
         }
@@ -1089,7 +1073,7 @@ static int rss_binary_string(struct zint_symbol *symbol, const unsigned char sou
 
         if (!general_field_encode(general_field, j, &mode, &last_digit, binary_string, &bp)) {
             /* Invalid characters in input data */
-            strcpy(symbol->errtxt, "386: Invalid characters in input data");
+            strcpy(symbol->errtxt, "386: Invalid characters in input data"); // TODO: Better error message
             return ZINT_ERROR_INVALID_DATA;
         }
     }
@@ -1102,16 +1086,8 @@ static int rss_binary_string(struct zint_symbol *symbol, const unsigned char sou
     }
     symbol_characters = ((bp + remainder) / 12) + 1;
 
-    if ((symbol->symbology == BARCODE_DBAR_EXPSTK) || (symbol->symbology == BARCODE_DBAR_EXPSTK_CC)) {
-        characters_per_row = symbol->option_2 * 2;
-
-        if ((characters_per_row < 2) || (characters_per_row > 20)) {
-            characters_per_row = 4;
-        }
-
-        if ((symbol_characters % characters_per_row) == 1) {
-            symbol_characters++;
-        }
+    if (characters_per_row && (symbol_characters % characters_per_row) == 1) { // DBAR_EXPSTK
+        symbol_characters++;
     }
 
     if (symbol_characters < 4) {
@@ -1139,16 +1115,8 @@ static int rss_binary_string(struct zint_symbol *symbol, const unsigned char sou
         }
         symbol_characters = ((bp + remainder) / 12) + 1;
 
-        if ((symbol->symbology == BARCODE_DBAR_EXPSTK) || (symbol->symbology == BARCODE_DBAR_EXPSTK_CC)) {
-            characters_per_row = symbol->option_2 * 2;
-
-            if ((characters_per_row < 2) || (characters_per_row > 20)) {
-                characters_per_row = 4;
-            }
-
-            if ((symbol_characters % characters_per_row) == 1) {
-                symbol_characters++;
-            }
+        if (characters_per_row && (symbol_characters % characters_per_row) == 1) { // DBAR_EXPSTK
+            symbol_characters++;
         }
 
         if (symbol_characters < 4) {
@@ -1161,7 +1129,7 @@ static int rss_binary_string(struct zint_symbol *symbol, const unsigned char sou
     }
 
     if (bp > 252) { /* 252 = (21 * 12) */
-        strcpy(symbol->errtxt, "387: Input too long");
+        strcpy(symbol->errtxt, "387: Input too long"); // TODO: Better error message
         return ZINT_ERROR_TOO_LONG;
     }
 
@@ -1282,6 +1250,7 @@ INTERNAL int rssexpanded_cc(struct zint_symbol *symbol, unsigned char source[],
     unsigned int bin_len = 13 * src_len + 200 + 1;
     int widths[4];
     int bp = 0;
+    int cols_per_row = 0;
     int stack_rows = 1;
 #ifndef _MSC_VER
     unsigned char reduced[src_len + 1];
@@ -1297,6 +1266,7 @@ INTERNAL int rssexpanded_cc(struct zint_symbol *symbol, unsigned char source[],
     if (error_number >= ZINT_ERROR) {
         return error_number;
     }
+    warn_number = error_number;
 
     if (symbol->debug & ZINT_DEBUG_PRINT) {
         printf("Reduced (%d): %s\n", (int) ustrlen(reduced), reduced);
@@ -1315,9 +1285,22 @@ INTERNAL int rssexpanded_cc(struct zint_symbol *symbol, unsigned char source[],
         binary_string[bp++] = '0';
     }
 
-    i = rss_binary_string(symbol, reduced, binary_string, &bp);
-    if (i != 0) {
-        return i;
+    if ((symbol->symbology == BARCODE_DBAR_EXPSTK) || (symbol->symbology == BARCODE_DBAR_EXPSTK_CC)) {
+        cols_per_row = 2; /* Default */
+        if (symbol->option_2 >= 1 && symbol->option_2 <= 11) {
+            cols_per_row = symbol->option_2;
+            if (cc_rows && (cols_per_row == 1)) {
+                /* "There shall be a minimum of four symbol characters in the
+                   first row of an RSS Expanded Stacked symbol when it is the linear
+                   component of an EAN.UCC Composite symbol." */
+                cols_per_row = 2;
+            }
+        }
+    }
+
+    error_number = rssexp_binary_string(symbol, reduced, binary_string, cols_per_row, &bp);
+    if (error_number != 0) {
+        return error_number;
     }
 
     data_chars = bp / 12;
@@ -1479,18 +1462,8 @@ INTERNAL int rssexpanded_cc(struct zint_symbol *symbol, unsigned char source[],
          * Patch by Daniel Frede
          */
 
-        if ((symbol->option_2 < 1) || (symbol->option_2 > 11)) {
-            symbol->option_2 = 2;
-        }
-        if (cc_rows && (symbol->option_2 == 1)) {
-            /* "There shall be a minimum of four symbol characters in the
-            first row of an RSS Expanded Stacked symbol when it is the linear
-            component of an EAN.UCC Composite symbol." */
-            symbol->option_2 = 2;
-        }
-
-        stack_rows = codeblocks / symbol->option_2;
-        if (codeblocks % symbol->option_2 > 0) {
+        stack_rows = codeblocks / cols_per_row;
+        if (codeblocks % cols_per_row > 0) {
             stack_rows++;
         }
 
@@ -1502,10 +1475,10 @@ INTERNAL int rssexpanded_cc(struct zint_symbol *symbol, unsigned char source[],
             int num_columns;
 
             /* Number of columns in current row */
-            if (current_row * symbol->option_2 > codeblocks) {
+            if (current_row * cols_per_row > codeblocks) {
                 num_columns = codeblocks - current_block;
             } else {
-                num_columns = symbol->option_2;
+                num_columns = cols_per_row;
             }
 
             /* Row Start */
@@ -1515,8 +1488,8 @@ INTERNAL int rssexpanded_cc(struct zint_symbol *symbol, unsigned char source[],
 
             /* If last row and is partial and even-numbered, and have even columns (segment pairs),
              * and odd number of finders (== odd number of columns) */
-            if ((current_row == stack_rows) && (num_columns != symbol->option_2) &&
-                    !(current_row & 1) && !(symbol->option_2 & 1) && (num_columns & 1)) {
+            if ((current_row == stack_rows) && (num_columns != cols_per_row) && !(current_row & 1)
+                    && !(cols_per_row & 1) && (num_columns & 1)) {
                 /* Special case bottom row */
                 special_case_row = 1;
                 sub_elements[0] = 2; /* Extra space (latch set below) */
@@ -1524,7 +1497,7 @@ INTERNAL int rssexpanded_cc(struct zint_symbol *symbol, unsigned char source[],
 
             /* If odd number of columns or current row odd-numbered or special case last row then left-to-right,
              * else right-to-left */
-            if ((symbol->option_2 & 1) || (current_row & 1) || special_case_row) {
+            if ((cols_per_row & 1) || (current_row & 1) || special_case_row) {
                 left_to_right = 1;
             } else {
                 left_to_right = 0;
@@ -1533,7 +1506,7 @@ INTERNAL int rssexpanded_cc(struct zint_symbol *symbol, unsigned char source[],
             if (symbol->debug & ZINT_DEBUG_PRINT) {
                 if (current_row == stack_rows) {
                     printf("Last row: number of columns: %d / %d, left to right: %d, special case: %d\n",
-                        num_columns, symbol->option_2, left_to_right, special_case_row);
+                        num_columns, cols_per_row, left_to_right, special_case_row);
                 }
             }
 
@@ -1553,7 +1526,7 @@ INTERNAL int rssexpanded_cc(struct zint_symbol *symbol, unsigned char source[],
                 }
                 reader++;
                 current_block++;
-            } while ((reader < symbol->option_2) && (current_block < codeblocks));
+            } while ((reader < cols_per_row) && (current_block < codeblocks));
 
             /* Row Stop */
             sub_elements[elements_in_sub] = 1; // right guard
@@ -1574,7 +1547,7 @@ INTERNAL int rssexpanded_cc(struct zint_symbol *symbol, unsigned char source[],
                 int odd_last_row = (current_row == stack_rows) && (data_chars % 2 == 0);
 
                 /* middle separator pattern (above current row) */
-                for (j = 5; j < (49 * symbol->option_2); j += 2) {
+                for (j = 5; j < (49 * cols_per_row); j += 2) {
                     set_module(symbol, symbol->rows - 2, j);
                 }
                 symbol->row_height[symbol->rows - 2] = 1;
@@ -1609,7 +1582,11 @@ INTERNAL int rssexpanded_cc(struct zint_symbol *symbol, unsigned char source[],
         symbol->height = symbol->height ? 34.0f : 34.0f * stack_rows; /* Pass back min row or default height */
     } else {
 #ifdef COMPLIANT_HEIGHTS
-        warn_number = set_height(symbol, 34.0f, 34.0f * stack_rows, 0.0f, 0 /*no_errtxt*/);
+        if (warn_number) {
+            (void) set_height(symbol, 34.0f, 34.0f * stack_rows, 0.0f, 0 /*no_errtxt*/);
+        } else {
+            warn_number = set_height(symbol, 34.0f, 34.0f * stack_rows, 0.0f, 0 /*no_errtxt*/);
+        }
 #else
         (void) set_height(symbol, 0.0f, 34.0f * stack_rows, 0.0f, 1 /*no_errtxt*/);
 #endif
diff --git a/backend/tests/test_code.c b/backend/tests/test_code.c
index b256e2d7..67ef34d3 100644
--- a/backend/tests/test_code.c
+++ b/backend/tests/test_code.c
@@ -205,11 +205,12 @@ static void test_input(int index, int debug) {
         /* 20*/ { BARCODE_PZN, -1, "A", -1, ZINT_ERROR_INVALID_DATA, -1, -1 },
         /* 21*/ { BARCODE_PZN, -1, "1000006", -1, ZINT_ERROR_INVALID_DATA, -1, -1 }, // Check digit == 10 so can't be used
         /* 22*/ { BARCODE_VIN, -1, "5GZCZ43D13S812715", -1, 0, 1, 246 },
-        /* 23*/ { BARCODE_VIN, -1, "5GZCZ43D23S812715", -1, ZINT_ERROR_INVALID_DATA, -1, -1 }, // North American with invalid check character
+        /* 23*/ { BARCODE_VIN, -1, "5GZCZ43D23S812715", -1, ZINT_ERROR_INVALID_CHECK, -1, -1 }, // North American with invalid check character
         /* 24*/ { BARCODE_VIN, -1, "WP0ZZZ99ZTS392124", -1, 0, 1, 246 }, // Not North American so no check
-        /* 25*/ { BARCODE_HIBC_39, -1, "a", -1, 0, 1, 79 }, // Converts to upper
-        /* 26*/ { BARCODE_HIBC_39, -1, ",", -1, ZINT_ERROR_INVALID_DATA, -1, -1 },
-        /* 27*/ { BARCODE_HIBC_39, -1, "\000", 1, ZINT_ERROR_INVALID_DATA, -1, -1 },
+        /* 25*/ { BARCODE_VIN, -1, "WPOZZZ99ZTS392124", -1, ZINT_ERROR_INVALID_DATA, -1, -1 }, // O not allowed
+        /* 26*/ { BARCODE_HIBC_39, -1, "a", -1, 0, 1, 79 }, // Converts to upper
+        /* 27*/ { BARCODE_HIBC_39, -1, ",", -1, ZINT_ERROR_INVALID_DATA, -1, -1 },
+        /* 28*/ { BARCODE_HIBC_39, -1, "\000", 1, ZINT_ERROR_INVALID_DATA, -1, -1 },
     };
     int data_size = ARRAY_SIZE(data);
     int i, length, ret;
diff --git a/backend/tests/test_code128.c b/backend/tests/test_code128.c
index bbb2ad0b..7b5e43e1 100644
--- a/backend/tests/test_code128.c
+++ b/backend/tests/test_code128.c
@@ -153,7 +153,7 @@ static void test_hrt_cpy_iso8859_1(int index, int debug) {
         }
         assert_equal(ret, data[i].ret, "i:%d ret %d != %d\n", i, ret, data[i].ret);
         assert_equal(ret, (int) ustrlen(symbol.text), "i:%d ret %d != strlen %d\n", i, ret, (int) ustrlen(symbol.text));
-        assert_nonzero(testUtilIsValidUTF8(symbol.text, ustrlen(symbol.text)), "i:%d testUtilIsValidUTF8(%s) != 1\n", i, symbol.text);
+        assert_nonzero(testUtilIsValidUTF8(symbol.text, (int) ustrlen(symbol.text)), "i:%d testUtilIsValidUTF8(%s) != 1\n", i, symbol.text);
         assert_zero(strcmp((char *) symbol.text, data[i].expected), "i:%d symbol.text (%s) != expected (%s)\n", i, symbol.text, data[i].expected);
     }
 
diff --git a/backend/tests/test_composite.c b/backend/tests/test_composite.c
index 46422c4e..c44119f9 100644
--- a/backend/tests/test_composite.c
+++ b/backend/tests/test_composite.c
@@ -89,7 +89,7 @@ static void test_eanx_leading_zeroes(int index, int debug) {
         assert_zero(length >= 128, "i:%d length %d >= 128\n", i, length);
         strcpy(symbol->primary, data[i].data);
 
-        composite_length = strlen(data[i].composite);
+        composite_length = (int) strlen(data[i].composite);
 
         ret = ZBarcode_Encode(symbol, (const unsigned char *) data[i].composite, composite_length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
@@ -109,8 +109,8 @@ static void test_helper_generate(const struct zint_symbol *symbol, int ret, int
     char esc_data[1024];
     char esc_composite[4096];
 
-    testUtilEscape(data, strlen(data), esc_data, sizeof(esc_data));
-    testUtilEscape(composite, strlen(composite), esc_composite, sizeof(esc_composite));
+    testUtilEscape(data, (int) strlen(data), esc_data, sizeof(esc_data));
+    testUtilEscape(composite, (int) strlen(composite), esc_composite, sizeof(esc_composite));
 
     if (ret == 0) {
         if (bwipp_cmp == -1) {
@@ -1245,7 +1245,7 @@ static void test_examples(int index, int generate, int debug) {
         assert_zero(length >= 128, "i:%d length %d >= 128\n", i, length);
         strcpy(symbol->primary, data[i].data);
 
-        composite_length = strlen(data[i].composite);
+        composite_length = (int) strlen(data[i].composite);
 
         ret = ZBarcode_Encode(symbol, (const unsigned char *) data[i].composite, composite_length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
@@ -1409,7 +1409,7 @@ static void test_odd_numbered_numeric(int index, int generate, int debug) {
         assert_zero(length >= 128, "i:%d length %d >= 128\n", i, length);
         strcpy(symbol->primary, data[i].data);
 
-        composite_length = strlen(data[i].composite);
+        composite_length = (int) strlen(data[i].composite);
 
         ret = ZBarcode_Encode(symbol, (const unsigned char *) data[i].composite, composite_length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
@@ -1537,7 +1537,7 @@ static void test_ean128_cc_shift(int index, int generate, int debug) {
         assert_zero(length >= 128, "i:%d length %d >= 128\n", i, length);
         strcpy(symbol->primary, data[i].data);
 
-        composite_length = strlen(data[i].composite);
+        composite_length = (int) strlen(data[i].composite);
 
         ret = ZBarcode_Encode(symbol, (const unsigned char *) data[i].composite, composite_length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
@@ -1617,7 +1617,7 @@ static void test_ean128_cc_width(int index, int generate, int debug) {
         assert_zero(length >= 128, "i:%d length %d >= 128\n", i, length);
         strcpy(symbol->primary, data[i].data);
 
-        composite_length = strlen(data[i].composite);
+        composite_length = (int) strlen(data[i].composite);
 
         ret = ZBarcode_Encode(symbol, (const unsigned char *) data[i].composite, composite_length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
@@ -2083,7 +2083,7 @@ static void test_encodation_0(int index, int generate, int debug) {
         assert_zero(length >= 128, "i:%d length %d >= 128\n", i, length);
         strcpy(symbol->primary, data[i].data);
 
-        composite_length = strlen(data[i].composite);
+        composite_length = (int) strlen(data[i].composite);
 
         ret = ZBarcode_Encode(symbol, (const unsigned char *) data[i].composite, composite_length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
@@ -2220,7 +2220,7 @@ static void test_encodation_10(int index, int generate, int debug) {
         assert_zero(length >= 128, "i:%d length %d >= 128\n", i, length);
         strcpy(symbol->primary, data[i].data);
 
-        composite_length = strlen(data[i].composite);
+        composite_length = (int) strlen(data[i].composite);
 
         ret = ZBarcode_Encode(symbol, (const unsigned char *) data[i].composite, composite_length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
@@ -2601,7 +2601,7 @@ static void test_encodation_11(int index, int generate, int debug) {
         assert_zero(length >= 128, "i:%d length %d >= 128\n", i, length);
         strcpy(symbol->primary, data[i].data);
 
-        composite_length = strlen(data[i].composite);
+        composite_length = (int) strlen(data[i].composite);
 
         ret = ZBarcode_Encode(symbol, (const unsigned char *) data[i].composite, composite_length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
@@ -2753,7 +2753,7 @@ static void test_addongap(int index, int generate, int debug) {
         assert_zero(length >= 128, "i:%d length %d >= 128\n", i, length);
         strcpy(symbol->primary, data[i].data);
 
-        composite_length = strlen(composite);
+        composite_length = (int) strlen(composite);
 
         ret = ZBarcode_Encode(symbol, (const unsigned char *) composite, composite_length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
@@ -2843,7 +2843,7 @@ static void test_gs1parens(int index, int debug) {
         assert_zero(length >= 128, "i:%d length %d >= 128\n", i, length);
         strcpy(symbol->primary, data[i].data);
 
-        composite_length = strlen(data[i].composite);
+        composite_length = (int) strlen(data[i].composite);
 
         ret = ZBarcode_Encode(symbol, (const unsigned char *) data[i].composite, composite_length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
@@ -2894,7 +2894,7 @@ static void test_fuzz(int index, int debug) {
         assert_zero(length >= 128, "i:%d length %d >= 128\n", i, length);
         strcpy(symbol->primary, data[i].data);
 
-        composite_length = strlen(data[i].composite);
+        composite_length = (int) strlen(data[i].composite);
 
         ret = ZBarcode_Encode(symbol, (const unsigned char *) data[i].composite, composite_length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
@@ -2966,7 +2966,7 @@ static void test_perf(int index, int debug) {
             assert_zero(length >= 128, "i:%d length %d >= 128\n", i, length);
             strcpy(symbol->primary, data[i].data);
 
-            composite_length = strlen(data[i].composite);
+            composite_length = (int) strlen(data[i].composite);
 
             start = clock();
             ret = ZBarcode_Encode(symbol, (const unsigned char *) data[i].composite, composite_length);
diff --git a/backend/tests/test_gs1.c b/backend/tests/test_gs1.c
index 2f84fd08..038b324a 100644
--- a/backend/tests/test_gs1.c
+++ b/backend/tests/test_gs1.c
@@ -1325,7 +1325,7 @@ static void test_gs1_verify(int index, int debug) {
         symbol = ZBarcode_Create();
         assert_nonnull(symbol, "Symbol not created\n");
 
-        length = strlen(data[i].data);
+        length = (int) strlen(data[i].data);
 
         ret = gs1_verify(symbol, (unsigned char *) data[i].data, length, (unsigned char *) reduced);
         assert_equal(ret, data[i].ret, "i:%d ret %d != %d (length %d \"%s\") %s\n", i, ret, data[i].ret, length, data[i].data, symbol->errtxt);
@@ -1730,7 +1730,7 @@ static void test_gs1_lint(int index, int debug) {
         symbol = ZBarcode_Create();
         assert_nonnull(symbol, "Symbol not created\n");
 
-        length = strlen(data[i].data);
+        length = (int) strlen(data[i].data);
 
         ret = gs1_verify(symbol, (unsigned char *) data[i].data, length, (unsigned char *) reduced);
         assert_equal(ret, data[i].ret, "i:%d ret %d != %d (length %d \"%s\") %s\n", i, ret, data[i].ret, length, data[i].data, symbol->errtxt);
diff --git a/backend/tests/test_imail.c b/backend/tests/test_imail.c
index 2d5f60f5..52e5b636 100644
--- a/backend/tests/test_imail.c
+++ b/backend/tests/test_imail.c
@@ -109,7 +109,7 @@ static void test_csv(int index, int debug) {
         symbol->symbology = BARCODE_USPS_IMAIL;
         symbol->debug |= debug;
 
-        ret = ZBarcode_Encode(symbol, (unsigned char *) data, strlen(data));
+        ret = ZBarcode_Encode(symbol, (unsigned char *) data, (int) strlen(data));
 
         if (strcmp(return_code, "00") == 0) {
 
diff --git a/backend/tests/test_large.c b/backend/tests/test_large.c
index 81f76cff..cf766080 100644
--- a/backend/tests/test_large.c
+++ b/backend/tests/test_large.c
@@ -33,13 +33,17 @@
 #include "../large.h"
 
 #if defined(__MINGW32__)
-#  define LX_FMT "I64"
+#  if __WORDSIZE == 32
+#    define LX_FMT "I32"
+#  else
+#    define LX_FMT "I64"
+#  endif
 #  if defined(__clang__)
 #    pragma GCC diagnostic ignored "-Wformat-non-iso"
 #  elif defined(__GNUC__)
 #    pragma GCC diagnostic ignored "-Wformat" /* Unfortunately doesn't seem to be way to only avoid non-ISO warnings */
 #  endif
-#elif defined(_MSC_VER)
+#elif defined(_MSC_VER) || __WORDSIZE == 32
 #  define LX_FMT "ll"
 #else
 #  define LX_FMT "l"
diff --git a/backend/tests/test_library.c b/backend/tests/test_library.c
index aaac5907..1d94a39d 100644
--- a/backend/tests/test_library.c
+++ b/backend/tests/test_library.c
@@ -379,7 +379,7 @@ static void test_encode_file_too_large(void) {
 
     fstream = fopen(filename, "w+");
     assert_nonnull(fstream, "fopen(%s) failed (%d)\n", filename, ferror(fstream));
-    ret = fwrite(buf, 1, sizeof(buf), fstream);
+    ret = (int) fwrite(buf, 1, sizeof(buf), fstream);
     assert_equal(ret, sizeof(buf), "fwrite return value: %d != %d\n", ret, (int)sizeof(buf));
     ret = fclose(fstream);
     assert_zero(ret, "fclose(%s) %d != 0\n", filename, ret);
diff --git a/backend/tests/test_pcx.c b/backend/tests/test_pcx.c
index a9885621..63448986 100644
--- a/backend/tests/test_pcx.c
+++ b/backend/tests/test_pcx.c
@@ -93,7 +93,7 @@ static void test_pcx(int index, int debug) {
         }
         symbol->debug |= debug;
 
-        length = strlen(data[i].data);
+        length = (int) strlen(data[i].data);
 
         ret = ZBarcode_Encode(symbol, (unsigned char *) data[i].data, length);
         assert_zero(ret, "i:%d %s ZBarcode_Encode ret %d != 0 %s\n", i, testUtilBarcodeName(data[i].symbology), ret, symbol->errtxt);
diff --git a/backend/tests/test_pdf417.c b/backend/tests/test_pdf417.c
index c48a35f7..81010624 100644
--- a/backend/tests/test_pdf417.c
+++ b/backend/tests/test_pdf417.c
@@ -1074,7 +1074,7 @@ static void test_fuzz(int index, int debug) {
 
         length = data[i].length;
         if (length == -1) {
-            length = strlen(data[i].data);
+            length = (int) strlen(data[i].data);
         }
 
         ret = ZBarcode_Encode(symbol, (unsigned char *) data[i].data, length);
diff --git a/backend/tests/test_qr.c b/backend/tests/test_qr.c
index 1ab82f3b..0b2632b6 100644
--- a/backend/tests/test_qr.c
+++ b/backend/tests/test_qr.c
@@ -1656,7 +1656,7 @@ static void test_microqr_padding(int index, int generate, int debug) {
         symbol->debug = ZINT_DEBUG_TEST; // Needed to get codeword dump in errtxt
         symbol->debug |= debug;
 
-        length = strlen(data[i].data);
+        length = (int) strlen(data[i].data);
 
         ret = ZBarcode_Encode(symbol, (unsigned char *) data[i].data, length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
diff --git a/backend/tests/test_raster.c b/backend/tests/test_raster.c
index 35eacb3f..ffd57ab2 100644
--- a/backend/tests/test_raster.c
+++ b/backend/tests/test_raster.c
@@ -274,7 +274,7 @@ static void test_buffer(int index, int generate, int debug) {
         } else {
             text = data[i].data;
         }
-        length = strlen(text);
+        length = (int) strlen(text);
 
         ret = ZBarcode_Encode(symbol, (unsigned char *) text, length);
         assert_zero(ret, "i:%d ZBarcode_Encode(%s) ret %d != 0 (%s)\n", i, testUtilBarcodeName(data[i].symbology), ret, symbol->errtxt);
@@ -380,7 +380,7 @@ static void test_upcean_hrt(int index, int debug) {
         }
         symbol->debug |= debug;
 
-        length = strlen(data[i].data);
+        length = (int) strlen(data[i].data);
 
         ret = ZBarcode_Encode_and_Buffer(symbol, (unsigned char *) data[i].data, length, 0);
         assert_equal(ret, data[i].ret, "i:%d ret %d != %d\n", i, ret, data[i].ret);
@@ -574,7 +574,7 @@ static void test_stacking(int index, int debug) {
         ret = ZBarcode_Encode(symbol, (unsigned char *) data[i].data, length);
         assert_zero(ret, "i:%d ret %d != zero\n", i, ret);
 
-        length2 = strlen(data[i].data2);
+        length2 = (int) strlen(data[i].data2);
         ret = ZBarcode_Encode(symbol, (unsigned char *) data[i].data2, length2);
         assert_zero(ret, "i:%d ret %d != zero\n", i, ret);
 
@@ -995,7 +995,7 @@ static void test_scale(int index, int debug) {
         } else {
             text = data[i].data;
         }
-        length = strlen(text);
+        length = (int) strlen(text);
 
         ret = ZBarcode_Encode(symbol, (unsigned char *) text, length);
         assert_zero(ret, "i:%d ZBarcode_Encode(%d) ret %d != 0 %s\n", i, data[i].symbology, ret, symbol->errtxt);
@@ -1207,8 +1207,8 @@ static void test_buffer_plot(int index, int generate, int debug) {
             ret = testUtilBitmapCmp(symbol, data[i].expected_bitmap, &row, &column);
             assert_zero(ret, "i:%d (%s) testUtilBitmapCmp ret %d != 0 column %d row %d (%s)\n", i, testUtilBarcodeName(data[i].symbology), ret, column, row, data[i].data);
 
-            fg_len = strlen(data[i].fgcolour);
-            bg_len = strlen(data[i].bgcolour);
+            fg_len = (int) strlen(data[i].fgcolour);
+            bg_len = (int) strlen(data[i].bgcolour);
             if (fg_len > 6 || bg_len > 6) {
                 assert_nonnull(symbol->alphamap, "i:%d ZBarcode_Buffer(%s) alphamap NULL\n", i, testUtilBarcodeName(data[i].symbology));
                 // TODO: check alphamap
@@ -1674,7 +1674,7 @@ static void test_height(int index, int generate, int debug) {
         } else {
             text = data[i].data;
         }
-        length = strlen(text);
+        length = (int) strlen(text);
 
         ret = ZBarcode_Encode(symbol, (unsigned char *) text, length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode(%s) ret %d != %d (%s)\n", i, testUtilBarcodeName(data[i].symbology), ret, data[i].ret, symbol->errtxt);
diff --git a/backend/tests/test_rss.c b/backend/tests/test_rss.c
index 08a9adca..36d4c806 100644
--- a/backend/tests/test_rss.c
+++ b/backend/tests/test_rss.c
@@ -794,7 +794,8 @@ static void test_examples(int index, int generate, int debug) {
 
         if (generate) {
             printf("        /*%3d*/ { %s, %d, \"%s\", %d, %d, %d, %d, \"%s\",\n",
-                    i, testUtilBarcodeName(symbol->symbology), data[i].option_2, data[i].data, data[i].ret, symbol->rows, symbol->width, data[i].bwipp_cmp, data[i].comment);
+                    i, testUtilBarcodeName(symbol->symbology), data[i].option_2,
+                    data[i].data, data[i].ret, symbol->rows, symbol->width, data[i].bwipp_cmp, data[i].comment);
             testUtilModulesPrint(symbol, "                     ", "\n");
             printf("                },\n");
         } else {
@@ -1228,6 +1229,7 @@ static void test_input(int index, int debug) {
 
     struct item {
         int symbology;
+        int option_2;
         char *data;
         int ret;
         int expected_rows;
@@ -1235,32 +1237,33 @@ static void test_input(int index, int debug) {
     };
     // s/\/\*[ 0-9]*\*\//\=printf("\/*%3d*\/", line(".") - line("'<"))
     struct item data[] = {
-        /*  0*/ { BARCODE_DBAR_OMN, "1234567890123", 0, 1, 96 },
-        /*  1*/ { BARCODE_DBAR_OMN, "123456789012A", ZINT_ERROR_INVALID_DATA, -1, -1 },
-        /*  2*/ { BARCODE_DBAR_OMN, "12345678901234", ZINT_ERROR_INVALID_CHECK, -1, -1 },
-        /*  3*/ { BARCODE_DBAR_OMN, "123456789012315", ZINT_ERROR_TOO_LONG, -1, -1 },
-        /*  4*/ { BARCODE_DBAR_LTD, "1234567890123", 0, 1, 79 },
-        /*  5*/ { BARCODE_DBAR_LTD, "123456789012A", ZINT_ERROR_INVALID_DATA, -1, -1 },
-        /*  6*/ { BARCODE_DBAR_LTD, "12345678901235", ZINT_ERROR_INVALID_CHECK, -1, -1 },
-        /*  7*/ { BARCODE_DBAR_LTD, "123456789012315", ZINT_ERROR_TOO_LONG, -1, -1 },
-        /*  8*/ { BARCODE_DBAR_LTD, "2234567890123", ZINT_ERROR_INVALID_DATA, -1, -1 },
-        /*  9*/ { BARCODE_DBAR_LTD, "22345678901238", ZINT_ERROR_INVALID_DATA, -1, -1 },
-        /* 10*/ { BARCODE_DBAR_EXP, "[01]12345678901234", ZINT_WARN_NONCOMPLIANT, 1, 134 },
-        /* 11*/ { BARCODE_DBAR_EXP, "[01]12345678901231", 0, 1, 134 },
-        /* 12*/ { BARCODE_DBAR_EXP, "[01]1234567890123A", ZINT_ERROR_INVALID_DATA, -1, -1 },
-        /* 13*/ { BARCODE_DBAR_EXP, "[01]123456789012315", ZINT_ERROR_INVALID_DATA, -1, -1 },
-        /* 14*/ { BARCODE_DBAR_STK, "1234567890123", 0, 3, 50 },
-        /* 15*/ { BARCODE_DBAR_STK, "123456789012A", ZINT_ERROR_INVALID_DATA, -1, -1 },
-        /* 16*/ { BARCODE_DBAR_STK, "12345678901235", ZINT_ERROR_INVALID_CHECK, -1, -1 },
-        /* 17*/ { BARCODE_DBAR_STK, "123456789012315", ZINT_ERROR_TOO_LONG, -1, -1 },
-        /* 18*/ { BARCODE_DBAR_OMNSTK, "1234567890123", 0, 5, 50 },
-        /* 19*/ { BARCODE_DBAR_OMNSTK, "123456789012A", ZINT_ERROR_INVALID_DATA, -1, -1 },
-        /* 20*/ { BARCODE_DBAR_OMNSTK, "12345678901236", ZINT_ERROR_INVALID_CHECK, -1, -1 },
-        /* 21*/ { BARCODE_DBAR_OMNSTK, "123456789012315", ZINT_ERROR_TOO_LONG, -1, -1 },
-        /* 22*/ { BARCODE_DBAR_EXPSTK, "[01]12345678901234", ZINT_WARN_NONCOMPLIANT, 5, 102 },
-        /* 22*/ { BARCODE_DBAR_EXPSTK, "[01]12345678901231", 0, 5, 102 },
-        /* 23*/ { BARCODE_DBAR_EXPSTK, "[01]123456789012A", ZINT_ERROR_INVALID_DATA, -1, -1 },
-        /* 24*/ { BARCODE_DBAR_EXPSTK, "[01]123456789012315", ZINT_ERROR_INVALID_DATA, -1, -1 },
+        /*  0*/ { BARCODE_DBAR_OMN, -1, "1234567890123", 0, 1, 96 },
+        /*  1*/ { BARCODE_DBAR_OMN, -1, "123456789012A", ZINT_ERROR_INVALID_DATA, -1, -1 },
+        /*  2*/ { BARCODE_DBAR_OMN, -1, "12345678901234", ZINT_ERROR_INVALID_CHECK, -1, -1 },
+        /*  3*/ { BARCODE_DBAR_OMN, -1, "123456789012315", ZINT_ERROR_TOO_LONG, -1, -1 },
+        /*  4*/ { BARCODE_DBAR_LTD, -1, "1234567890123", 0, 1, 79 },
+        /*  5*/ { BARCODE_DBAR_LTD, -1, "123456789012A", ZINT_ERROR_INVALID_DATA, -1, -1 },
+        /*  6*/ { BARCODE_DBAR_LTD, -1, "12345678901235", ZINT_ERROR_INVALID_CHECK, -1, -1 },
+        /*  7*/ { BARCODE_DBAR_LTD, -1, "123456789012315", ZINT_ERROR_TOO_LONG, -1, -1 },
+        /*  8*/ { BARCODE_DBAR_LTD, -1, "2234567890123", ZINT_ERROR_INVALID_DATA, -1, -1 },
+        /*  9*/ { BARCODE_DBAR_LTD, -1, "22345678901238", ZINT_ERROR_INVALID_DATA, -1, -1 },
+        /* 10*/ { BARCODE_DBAR_EXP, -1, "[01]12345678901234", ZINT_WARN_NONCOMPLIANT, 1, 134 },
+        /* 11*/ { BARCODE_DBAR_EXP, -1, "[01]12345678901231", 0, 1, 134 },
+        /* 12*/ { BARCODE_DBAR_EXP, -1, "[01]1234567890123A", ZINT_ERROR_INVALID_DATA, -1, -1 },
+        /* 13*/ { BARCODE_DBAR_EXP, -1, "[01]123456789012315", ZINT_ERROR_INVALID_DATA, -1, -1 },
+        /* 14*/ { BARCODE_DBAR_STK, -1, "1234567890123", 0, 3, 50 },
+        /* 15*/ { BARCODE_DBAR_STK, -1, "123456789012A", ZINT_ERROR_INVALID_DATA, -1, -1 },
+        /* 16*/ { BARCODE_DBAR_STK, -1, "12345678901235", ZINT_ERROR_INVALID_CHECK, -1, -1 },
+        /* 17*/ { BARCODE_DBAR_STK, -1, "123456789012315", ZINT_ERROR_TOO_LONG, -1, -1 },
+        /* 18*/ { BARCODE_DBAR_OMNSTK, -1, "1234567890123", 0, 5, 50 },
+        /* 19*/ { BARCODE_DBAR_OMNSTK, -1, "123456789012A", ZINT_ERROR_INVALID_DATA, -1, -1 },
+        /* 20*/ { BARCODE_DBAR_OMNSTK, -1, "12345678901236", ZINT_ERROR_INVALID_CHECK, -1, -1 },
+        /* 21*/ { BARCODE_DBAR_OMNSTK, -1, "123456789012315", ZINT_ERROR_TOO_LONG, -1, -1 },
+        /* 22*/ { BARCODE_DBAR_EXPSTK, -1, "[01]12345678901234", ZINT_WARN_NONCOMPLIANT, 5, 102 },
+        /* 23*/ { BARCODE_DBAR_EXPSTK, -1, "[01]12345678901231", 0, 5, 102 },
+        /* 24*/ { BARCODE_DBAR_EXPSTK, -1, "[01]123456789012A", ZINT_ERROR_INVALID_DATA, -1, -1 },
+        /* 25*/ { BARCODE_DBAR_EXPSTK, -1, "[01]123456789012315", ZINT_ERROR_INVALID_DATA, -1, -1 },
+        /* 26*/ { BARCODE_DBAR_EXPSTK, 1, "[01]12345678901231", 0, 9, 53 },
     };
     int data_size = ARRAY_SIZE(data);
     int i, length, ret;
@@ -1275,7 +1278,7 @@ static void test_input(int index, int debug) {
         symbol = ZBarcode_Create();
         assert_nonnull(symbol, "Symbol not created\n");
 
-        length = testUtilSetSymbol(symbol, data[i].symbology, -1 /*input_mode*/, -1 /*eci*/, -1 /*option_1*/, -1, -1, -1 /*output_options*/, data[i].data, -1, debug);
+        length = testUtilSetSymbol(symbol, data[i].symbology, -1 /*input_mode*/, -1 /*eci*/, -1 /*option_1*/, data[i].option_2, -1, -1 /*output_options*/, data[i].data, -1, debug);
 
         ret = ZBarcode_Encode(symbol, (const unsigned char *) data[i].data, length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
diff --git a/backend/tests/test_svg.c b/backend/tests/test_svg.c
index f0abf2dc..92c0d969 100644
--- a/backend/tests/test_svg.c
+++ b/backend/tests/test_svg.c
@@ -155,7 +155,7 @@ static void test_print(int index, int generate, int debug) {
         } else {
             text = data[i].data;
         }
-        text_length = strlen(text);
+        text_length = (int) strlen(text);
 
         ret = ZBarcode_Encode(symbol, (unsigned char *) text, text_length);
         assert_equal(ret, data[i].ret, "i:%d %s ZBarcode_Encode ret %d != %d (%s)\n", i, testUtilBarcodeName(data[i].symbology), ret, data[i].ret, symbol->errtxt);
diff --git a/backend/tests/test_tif.c b/backend/tests/test_tif.c
index 5c51c6cd..6036235c 100644
--- a/backend/tests/test_tif.c
+++ b/backend/tests/test_tif.c
@@ -238,7 +238,7 @@ static void test_print(int index, int generate, int debug) {
         } else {
             text = data[i].data;
         }
-        text_length = strlen(text);
+        text_length = (int) strlen(text);
 
         ret = ZBarcode_Encode(symbol, (unsigned char *) text, text_length);
         assert_zero(ret, "i:%d %s ZBarcode_Encode ret %d != 0 %s\n", i, testUtilBarcodeName(data[i].symbology), ret, symbol->errtxt);
diff --git a/backend/tests/test_vector.c b/backend/tests/test_vector.c
index e90699b4..e847d34d 100644
--- a/backend/tests/test_vector.c
+++ b/backend/tests/test_vector.c
@@ -290,7 +290,7 @@ static void test_buffer_vector(int index, int generate, int debug) {
         } else {
             text = data[i].data;
         }
-        length = strlen(text);
+        length = (int) strlen(text);
 
         ret = ZBarcode_Encode(symbol, (unsigned char *) text, length);
         assert_zero(ret, "i:%d ZBarcode_Encode(%d) ret %d != 0 %s\n", i, data[i].symbology, ret, symbol->errtxt);
@@ -397,7 +397,7 @@ static void test_upcean_hrt(int index, int debug) {
         }
         symbol->debug |= debug;
 
-        length = strlen(data[i].data);
+        length = (int) strlen(data[i].data);
 
         ret = ZBarcode_Encode(symbol, (unsigned char *) data[i].data, length);
         assert_zero(ret, "i:%d ZBarcode_Encode(%d) ret %d != 0 %s\n", i, data[i].symbology, ret, symbol->errtxt);
@@ -554,7 +554,7 @@ static void test_stacking(int index, int debug) {
         ret = ZBarcode_Encode(symbol, (unsigned char *) data[i].data, length);
         assert_zero(ret, "i:%d ret %d != zero\n", i, ret);
 
-        length2 = strlen(data[i].data2);
+        length2 = (int) strlen(data[i].data2);
         ret = ZBarcode_Encode(symbol, (unsigned char *) data[i].data2, length2);
         assert_zero(ret, "i:%d ret %d != zero\n", i, ret);
 
@@ -754,7 +754,7 @@ static void test_noncomposite_string_x(int index, int debug) {
         symbol->input_mode = UNICODE_MODE;
         symbol->debug |= debug;
 
-        length = strlen(data[i].data);
+        length = (int) strlen(data[i].data);
 
         ret = ZBarcode_Encode(symbol, (unsigned char *) data[i].data, length);
         assert_zero(ret, "i:%d ZBarcode_Encode(%d) ret %d != 0 %s\n", i, data[i].symbology, ret, symbol->errtxt);
@@ -815,7 +815,7 @@ static void test_upcean_whitespace_width(int index, int debug) {
         symbol->whitespace_width = data[i].whitespace_width;
         symbol->debug |= debug;
 
-        length = strlen(data[i].data);
+        length = (int) strlen(data[i].data);
 
         ret = ZBarcode_Encode(symbol, (unsigned char *) data[i].data, length);
         assert_zero(ret, "i:%d ZBarcode_Encode(%d) ret %d != 0 %s\n", i, data[i].symbology, ret, symbol->errtxt);
@@ -1298,7 +1298,7 @@ static void test_height(int index, int generate, int debug) {
         } else {
             text = data[i].data;
         }
-        length = strlen(text);
+        length = (int) strlen(text);
 
         ret = ZBarcode_Encode(symbol, (unsigned char *) text, length);
         assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode(%s) ret %d != %d (%s)\n", i, testUtilBarcodeName(data[i].symbology), ret, data[i].ret, symbol->errtxt);
diff --git a/backend/tests/testcommon.c b/backend/tests/testcommon.c
index 9be31689..707b651e 100644
--- a/backend/tests/testcommon.c
+++ b/backend/tests/testcommon.c
@@ -64,10 +64,13 @@ static int failed = 0;
 static int skipped = 0;
 int assertionFailed = 0;
 int assertionNum = 0;
+const char *assertionFilename = "";
 static const char *testName = NULL;
 static const char *testFunc = NULL;
 
-#if _MSC_VER == 1200
+/* Visual C++ 6 doesn't support variadic args to macros, so make do with functions, which have inferior behaviour,
+   e.g. don't exit on failure, `assert_equal()` type-specific */
+#if _MSC_VER == 1200 /* VC6 */
 #include <stdarg.h>
 void assert_zero(int exp, const char *fmt, ...) {
     assertionNum++;
@@ -113,9 +116,10 @@ void assert_notequal(int e1, int e2, const char *fmt, ...) {
 }
 #endif
 
+/* Begin individual test function */
 void testStartReal(const char *func, const char *name) {
     tests++;
-    if (*func && name && *name && strcmp(func, name) == 0) {
+    if (func && *func && name && *name && strcmp(func, name) == 0) {
         testName = "";
     } else {
         testName = name;
@@ -126,22 +130,9 @@ void testStartReal(const char *func, const char *name) {
     printf("_____%d: %s: %s...\n", tests, testFunc, testName ? testName : "");
 }
 
-void testEnd(int result) {
-    if (testName && testName[0]) {
-        printf(".....%d: %s: %s ", tests, testFunc, testName);
-    } else {
-        printf(".....%d: %s: ", tests, testFunc);
-    }
-    if (result) {
-        puts("FAILED.");
-        failed++;
-    } else {
-        puts("PASSED.");
-    }
-}
-
+/* End individual test function */
 void testFinish(void) {
-    if (testName && testName[0]) {
+    if (testName && *testName) {
         printf(".....%d: %s: %s ", tests, testFunc, testName);
     } else {
         printf(".....%d: %s: ", tests, testFunc);
@@ -154,9 +145,10 @@ void testFinish(void) {
     }
 }
 
+/* Skip (and end) individual test function */
 void testSkip(const char *msg) {
     skipped++;
-    if (testName && testName[0]) {
+    if (testName && *testName) {
         printf(".....%d: %s: %s ", tests, testFunc, testName);
     } else {
         printf(".....%d: %s: ", tests, testFunc);
@@ -169,6 +161,7 @@ void testSkip(const char *msg) {
     }
 }
 
+/* End test program */
 void testReport() {
     if (failed && skipped) {
         printf("Total %d tests, %d skipped, %d fails.\n", tests, skipped, failed);
@@ -187,6 +180,7 @@ void testReport() {
     }
 }
 
+/* Begin test program, parse args */
 void testRun(int argc, char *argv[], testFunction funcs[], int funcs_size) {
     int i, opt, ran;
     long long_opt;
@@ -206,6 +200,20 @@ void testRun(int argc, char *argv[], testFunction funcs[], int funcs_size) {
     typedef void (*func_index_generate)(int index, int generate);
     typedef void (*func_index_generate_debug)(int index, int generate, int debug);
 
+    if (argc) {
+        char *filename = strrchr(argv[0], '/');
+#ifdef _WIN32
+        if (filename == NULL) {
+            filename = strrchr(argv[0], '\\');
+        }
+#endif
+        if (filename) {
+            assertionFilename = filename + 1;
+        } else {
+            assertionFilename = argv[0];
+        }
+    }
+
     while ((opt = getopt(argc, argv, "d:f:gi:")) != -1) {
         switch (opt) {
             case 'd':
@@ -290,6 +298,37 @@ void testRun(int argc, char *argv[], testFunction funcs[], int funcs_size) {
     }
 }
 
+/* Helper to set common symbol fields */
+int testUtilSetSymbol(struct zint_symbol *symbol, int symbology, int input_mode, int eci, int option_1, int option_2,
+            int option_3, int output_options, char *data, int length, int debug) {
+    symbol->symbology = symbology;
+    if (input_mode != -1) {
+        symbol->input_mode = input_mode;
+    }
+    if (eci != -1) {
+        symbol->eci = eci;
+    }
+    if (option_1 != -1) {
+        symbol->option_1 = option_1;
+    }
+    if (option_2 != -1) {
+        symbol->option_2 = option_2;
+    }
+    if (option_3 != -1) {
+        symbol->option_3 = option_3;
+    }
+    if (output_options != -1) {
+        symbol->output_options = output_options;
+    }
+    symbol->debug |= debug;
+    if (length == -1) {
+        length = (int) strlen(data);
+    }
+
+    return length;
+}
+
+/* Pretty name for symbology */
 const char *testUtilBarcodeName(int symbology) {
     struct item {
         const char *name;
@@ -449,41 +488,15 @@ const char *testUtilBarcodeName(int symbology) {
     if (symbology < 0 || symbology >= data_size) {
         return "";
     }
-    if (data[symbology].val != symbology || (data[symbology].define != -1 && data[symbology].define != symbology)) { // Self-check
+    // Self-check
+    if (data[symbology].val != symbology || (data[symbology].define != -1 && data[symbology].define != symbology)) {
         fprintf(stderr, "testUtilBarcodeName: data table out of sync (%d)\n", symbology);
         abort();
     }
     return data[symbology].name;
 }
 
-int testUtilSetSymbol(struct zint_symbol *symbol, int symbology, int input_mode, int eci, int option_1, int option_2, int option_3, int output_options, char *data, int length, int debug) {
-    symbol->symbology = symbology;
-    if (input_mode != -1) {
-        symbol->input_mode = input_mode;
-    }
-    if (eci != -1) {
-        symbol->eci = eci;
-    }
-    if (option_1 != -1) {
-        symbol->option_1 = option_1;
-    }
-    if (option_2 != -1) {
-        symbol->option_2 = option_2;
-    }
-    if (option_3 != -1) {
-        symbol->option_3 = option_3;
-    }
-    if (output_options != -1) {
-        symbol->output_options = output_options;
-    }
-    symbol->debug |= debug;
-    if (length == -1) {
-        length = strlen(data);
-    }
-
-    return length;
-}
-
+/* Pretty name for error/warning */
 const char *testUtilErrorName(int error_number) {
     struct item {
         const char *name;
@@ -509,13 +522,16 @@ const char *testUtilErrorName(int error_number) {
     if (error_number < 0 || error_number >= data_size) {
         return "";
     }
-    if (data[error_number].val != error_number || (data[error_number].define != -1 && data[error_number].define != error_number)) { // Self-check
+    // Self-check
+    if (data[error_number].val != error_number
+            || (data[error_number].define != -1 && data[error_number].define != error_number)) {
         fprintf(stderr, "testUtilErrorName: data table out of sync (%d)\n", error_number);
         abort();
     }
     return data[error_number].name;
 }
 
+/* Pretty name for input mode */
 const char *testUtilInputModeName(int input_mode) {
     static char buf[512];
 
@@ -564,6 +580,7 @@ const char *testUtilInputModeName(int input_mode) {
     return buf;
 }
 
+/* Pretty name for option 3 */
 const char *testUtilOption3Name(int option_3) {
     static char buffer[64];
 
@@ -604,6 +621,7 @@ const char *testUtilOption3Name(int option_3) {
     return name;
 }
 
+/* Pretty name for output options */
 const char *testUtilOutputOptionsName(int output_options) {
     static char buf[512];
 
@@ -650,12 +668,14 @@ const char *testUtilOutputOptionsName(int output_options) {
         }
     }
     if (set != output_options) {
-        fprintf(stderr, "testUtilOutputOptionsName: unknown output option(s) %d (%d)\n", output_options & set, output_options);
+        fprintf(stderr, "testUtilOutputOptionsName: unknown output option(s) %d (%d)\n",
+                output_options & set, output_options);
         abort();
     }
     return buf;
 }
 
+/* Convert modules spanning 3 rows to DAFT equivalents */
 int testUtilDAFTConvert(const struct zint_symbol *symbol, char *buffer, int buffer_size) {
     int i;
     char *b = buffer;
@@ -692,6 +712,7 @@ int testUtilIsValidUTF8(const unsigned char str[], const int length) {
     return state == 0;
 }
 
+/* Escape data for printing on generate test. Has a number of issues, e.g. need to use octal escapes */
 char *testUtilEscape(char *buffer, int length, char *escaped, int escaped_size) {
     int i;
     unsigned char *b = (unsigned char *) buffer;
@@ -727,6 +748,7 @@ char *testUtilEscape(char *buffer, int length, char *escaped, int escaped_size)
     return escaped;
 }
 
+/* Helper to read a CSV field */
 char *testUtilReadCSVField(char *buffer, char *field, int field_size) {
     int i;
     char *b = buffer;
@@ -740,9 +762,10 @@ char *testUtilReadCSVField(char *buffer, char *field, int field_size) {
     return b;
 }
 
+/* Helper to fill a buffer (for "large" tests) - single-byte filler only */
 void testUtilStrCpyRepeat(char *buffer, char *repeat, int size) {
     int i;
-    int len = strlen(repeat);
+    int len = (int) strlen(repeat);
     int max = size - len;
     if (len == 0) {
         fprintf(stderr, "testUtilStrCpyRepeat: only use non-empty, non-NUL single-byte data for repeat pattern\n");
@@ -755,6 +778,7 @@ void testUtilStrCpyRepeat(char *buffer, char *repeat, int size) {
     buffer[size] = '\0';
 }
 
+/* Compare some "important" symbol fields for equality */
 int testUtilSymbolCmp(const struct zint_symbol *a, const struct zint_symbol *b) {
     int i, j;
     if (a->symbology != b->symbology) {
@@ -802,6 +826,7 @@ int testUtilSymbolCmp(const struct zint_symbol *a, const struct zint_symbol *b)
     return 0;
 }
 
+/* Copy a full vector structure (for later comparison) */
 struct zint_vector *testUtilVectorCpy(const struct zint_vector *in) {
     struct zint_vector_rect *rect;
     struct zint_vector_string *string;
@@ -876,6 +901,7 @@ struct zint_vector *testUtilVectorCpy(const struct zint_vector *in) {
     return out;
 }
 
+/* Compare 2 full vector structures */
 int testUtilVectorCmp(const struct zint_vector *a, const struct zint_vector *b) {
     struct zint_vector_rect *arect;
     struct zint_vector_string *astring;
@@ -1010,6 +1036,7 @@ int testUtilVectorCmp(const struct zint_vector *a, const struct zint_vector *b)
     return 0;
 }
 
+/* Dump modules into buffer as '0'/'1' (or colours 'W', 'C', 'B' etc if Ultra) */
 int testUtilModulesDump(const struct zint_symbol *symbol, char dump[], int dump_size) {
     int r, w;
     char *d = dump;
@@ -1033,6 +1060,7 @@ int testUtilModulesDump(const struct zint_symbol *symbol, char dump[], int dump_
     return d - dump;
 }
 
+/* Print out module dump (for generate tests) */
 void testUtilModulesPrint(const struct zint_symbol *symbol, const char *prefix, const char *postfix) {
     int r;
     for (r = 0; r < symbol->rows; r++) {
@@ -1040,6 +1068,8 @@ void testUtilModulesPrint(const struct zint_symbol *symbol, const char *prefix,
     }
 }
 
+/* Print out a single row of a module dump (for generate tests where rows all the same, to avoid large dumps of
+   duplicate data) */
 void testUtilModulesPrintRow(const struct zint_symbol *symbol, int row, const char *prefix, const char *postfix) {
     int w;
     if (*prefix) {
@@ -1061,6 +1091,7 @@ void testUtilModulesPrintRow(const struct zint_symbol *symbol, int row, const ch
     }
 }
 
+/* Whether 2 module dumps are the same */
 int testUtilModulesCmp(const struct zint_symbol *symbol, const char *expected, int *width, int *row) {
     const char *e = expected;
     const char *ep = expected + strlen(expected);
@@ -1093,6 +1124,7 @@ int testUtilModulesCmp(const struct zint_symbol *symbol, const char *expected, i
     return e != ep || r != symbol->rows || w != symbol->width ? 1 /*fail*/ : 0 /*success*/;
 }
 
+/* Whether 2 module row dumps are the same */
 int testUtilModulesCmpRow(const struct zint_symbol *symbol, int row, const char *expected, int *width) {
     const char *e = expected;
     const char *ep = expected + strlen(expected);
@@ -1118,50 +1150,7 @@ int testUtilModulesCmpRow(const struct zint_symbol *symbol, int row, const char
     return e != ep || w != symbol->width ? 1 /*fail*/ : 0 /*success*/;
 }
 
-int testUtilModulesDumpHex(const struct zint_symbol *symbol, char dump[], int dump_size) {
-    int i, r;
-    char hex[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8',
-        '9', 'A', 'B', 'C', 'D', 'E', 'F'};
-    int space = 0;
-    char *d = dump;
-    char *de = dump + dump_size;
-
-    for (r = 0; r < symbol->rows && d < de; r++) {
-        int byt = 0;
-        for (i = 0; i < symbol->width && d < de; i++) {
-            if (space == 2) {
-                *d++ = ' ';
-                space = 0;
-            }
-            byt = byt << 1;
-            if (symbol->symbology == BARCODE_ULTRA) {
-                if (module_colour_is_set(symbol, r, i)) {
-                    byt += 1;
-                }
-            } else {
-                if (module_is_set(symbol, r, i)) {
-                    byt += 1;
-                }
-            }
-            if (d < de && ((i + 1) % 4) == 0) {
-                *d++ = hex[byt];
-                space++;
-                byt = 0;
-            }
-        }
-        if (d < de && (symbol->width % 4) != 0) {
-            byt = byt << (4 - (symbol->width % 4));
-            *d++ = hex[byt];
-            space++;
-        }
-    }
-    if (d == de) {
-        return -1;
-    }
-    *d = '\0';
-    return d - dump;
-}
-
+/* Dump an unsigned int array as hex */
 char *testUtilUIntArrayDump(unsigned int *array, int size, char *dump, int dump_size) {
     int i, cnt_len = 0;
 
@@ -1175,6 +1164,7 @@ char *testUtilUIntArrayDump(unsigned int *array, int size, char *dump, int dump_
     return dump;
 }
 
+/* Dump an unsigned char array as hex */
 char *testUtilUCharArrayDump(unsigned char *array, int size, char *dump, int dump_size) {
     int i, cnt_len = 0;
 
@@ -1188,6 +1178,110 @@ char *testUtilUCharArrayDump(unsigned char *array, int size, char *dump, int dum
     return dump;
 }
 
+/* Dump a bitmap to stdout, for generate tests. Also useful for debugging */
+void testUtilBitmapPrint(const struct zint_symbol *symbol, const char *prefix, const char *postfix) {
+    static const char colour[] = { '0', 'C', 'M', 'B', 'Y', 'G', 'R', '1' };
+    int row, column, i, j;
+
+    if (!prefix) {
+        fputs("     ", stdout);
+        for (column = 0; column < symbol->bitmap_width; column += 10) printf("%-3d       ", column);
+        fputs("\n     ", stdout);
+        for (column = 0; column < symbol->bitmap_width; column++) printf("%d", column % 10);
+        putchar('\n');
+    }
+
+    for (row = 0; row < symbol->bitmap_height; row++) {
+        if (!prefix) {
+            printf("%3d: ", row);
+        } else {
+            if (*prefix) {
+                fputs(prefix, stdout);
+            }
+            putchar('"');
+        }
+        for (column = 0; column < symbol->bitmap_width; column++) {
+            if (symbol->output_options & OUT_BUFFER_INTERMEDIATE) {
+                putchar(symbol->bitmap[(row * symbol->bitmap_width) + column]);
+            } else {
+                i = ((row * symbol->bitmap_width) + column) * 3;
+                if ((symbol->bitmap[i] == 0 || symbol->bitmap[i] == 0xff)
+                        && (symbol->bitmap[i + 1] == 0 || symbol->bitmap[i + 1] == 0xff)
+                        && (symbol->bitmap[i + 2] == 0 || symbol->bitmap[i + 2] == 0xff)) {
+                    j = !symbol->bitmap[i] + !symbol->bitmap[i + 1] * 2 + !symbol->bitmap[i + 2] * 4;
+                    putchar(colour[j]);
+                } else {
+                    printf("%02X%02X%02X", symbol->bitmap[i], symbol->bitmap[i + 1], symbol->bitmap[i + 2]);
+                }
+            }
+        }
+        if (!postfix) {
+            putchar('\n');
+        } else {
+            putchar('"');
+            if (*postfix) {
+                fputs(postfix, stdout);
+            }
+        }
+    }
+
+    if (!postfix) {
+        fputs("     ", stdout);
+        for (column = 0; column < symbol->bitmap_width; column++) printf("%d", column % 10);
+        fputs("\n     ", stdout);
+        for (column = 0; column < symbol->bitmap_width; column += 10) printf("%-3d       ", column);
+        putchar('\n');
+    }
+}
+
+/* Compare a bitmap to a dump */
+int testUtilBitmapCmp(const struct zint_symbol *symbol, const char *expected, int *row, int *column) {
+    static const char colour[] = { '0', 'C', 'M', 'B', 'Y', 'G', 'R', '1' };
+    int r, c = -1, i, j;
+    const char *e = expected;
+    const char *ep = expected + strlen(expected);
+    char buf[7];
+
+    for (r = 0; r < symbol->bitmap_height; r++) {
+        for (c = 0; c < symbol->bitmap_width; c++) {
+            if (symbol->output_options & OUT_BUFFER_INTERMEDIATE) {
+                if (*e != symbol->bitmap[(r * symbol->bitmap_width) + c]) {
+                    *row = r;
+                    *column = c;
+                    return 1 /*fail*/;
+                }
+                e++;
+            } else {
+                i = ((r * symbol->bitmap_width) + c) * 3;
+                if ((symbol->bitmap[i] == 0 || symbol->bitmap[i] == 0xff)
+                        && (symbol->bitmap[i + 1] == 0 || symbol->bitmap[i + 1] == 0xff)
+                        && (symbol->bitmap[i + 2] == 0 || symbol->bitmap[i + 2] == 0xff)) {
+                    j = !symbol->bitmap[i] + !symbol->bitmap[i + 1] * 2 + !symbol->bitmap[i + 2] * 4;
+                    if (*e != colour[j]) {
+                        *row = r;
+                        *column = c;
+                        return 1 /*fail*/;
+                    }
+                    e++;
+                } else {
+                    sprintf(buf, "%02X%02X%02X", symbol->bitmap[i], symbol->bitmap[i + 1], symbol->bitmap[i + 2]);
+                    if (strncmp(buf, e, 6) != 0) {
+                        *row = r;
+                        *column = c;
+                        return 1 /*fail*/;
+                    }
+                    e += 6;
+                }
+            }
+        }
+    }
+
+    *row = r;
+    *column = c;
+    return e != ep || r != symbol->bitmap_height || c != symbol->bitmap_width ? 1 /*fail*/ : 0 /*success*/;
+}
+
+/* Determine the location of test data relative to where the test is being run */
 int testUtilDataPath(char *buffer, int buffer_size, const char *subdir, const char *filename) {
     int subdir_len = subdir ? (int) strlen(subdir) : 0;
     int filename_len = filename ? (int) strlen(filename) : 0;
@@ -1277,105 +1371,7 @@ int testUtilDataPath(char *buffer, int buffer_size, const char *subdir, const ch
     return 1;
 }
 
-void testUtilBitmapPrint(const struct zint_symbol *symbol, const char *prefix, const char *postfix) {
-    static const char colour[] = { '0', 'C', 'M', 'B', 'Y', 'G', 'R', '1' };
-    int row, column, i, j;
-
-    if (!prefix) {
-        fputs("     ", stdout);
-        for (column = 0; column < symbol->bitmap_width; column += 10) printf("%-3d       ", column);
-        fputs("\n     ", stdout);
-        for (column = 0; column < symbol->bitmap_width; column++) printf("%d", column % 10);
-        putchar('\n');
-    }
-
-    for (row = 0; row < symbol->bitmap_height; row++) {
-        if (!prefix) {
-            printf("%3d: ", row);
-        } else {
-            if (*prefix) {
-                fputs(prefix, stdout);
-            }
-            putchar('"');
-        }
-        for (column = 0; column < symbol->bitmap_width; column++) {
-            if (symbol->output_options & OUT_BUFFER_INTERMEDIATE) {
-                putchar(symbol->bitmap[(row * symbol->bitmap_width) + column]);
-            } else {
-                i = ((row * symbol->bitmap_width) + column) * 3;
-                if ((symbol->bitmap[i] == 0 || symbol->bitmap[i] == 0xff) && (symbol->bitmap[i + 1] == 0 || symbol->bitmap[i + 1] == 0xff)
-                        && (symbol->bitmap[i + 2] == 0 || symbol->bitmap[i + 2] == 0xff)) {
-                    j = (symbol->bitmap[i] == 0) + (symbol->bitmap[i + 1] == 0) * 2 + (symbol->bitmap[i + 2] == 0) * 4;
-                    putchar(colour[j]);
-                } else {
-                    printf("%02X%02X%02X", symbol->bitmap[i], symbol->bitmap[i + 1], symbol->bitmap[i + 2]);
-                }
-            }
-        }
-        if (!postfix) {
-            putchar('\n');
-        } else {
-            putchar('"');
-            if (*postfix) {
-                fputs(postfix, stdout);
-            }
-        }
-    }
-
-    if (!postfix) {
-        fputs("     ", stdout);
-        for (column = 0; column < symbol->bitmap_width; column++) printf("%d", column % 10);
-        fputs("\n     ", stdout);
-        for (column = 0; column < symbol->bitmap_width; column += 10) printf("%-3d       ", column);
-        putchar('\n');
-    }
-}
-
-int testUtilBitmapCmp(const struct zint_symbol *symbol, const char *expected, int *row, int *column) {
-    static const char colour[] = { '0', 'C', 'M', 'B', 'Y', 'G', 'R', '1' };
-    int r, c = -1, i, j;
-    const char *e = expected;
-    const char *ep = expected + strlen(expected);
-    char buf[7];
-
-    for (r = 0; r < symbol->bitmap_height; r++) {
-        for (c = 0; c < symbol->bitmap_width; c++) {
-            if (symbol->output_options & OUT_BUFFER_INTERMEDIATE) {
-                if (*e != symbol->bitmap[(r * symbol->bitmap_width) + c]) {
-                    *row = r;
-                    *column = c;
-                    return 1 /*fail*/;
-                }
-                e++;
-            } else {
-                i = ((r * symbol->bitmap_width) + c) * 3;
-                if ((symbol->bitmap[i] == 0 || symbol->bitmap[i] == 0xff) && (symbol->bitmap[i + 1] == 0 || symbol->bitmap[i + 1] == 0xff)
-                        && (symbol->bitmap[i + 2] == 0 || symbol->bitmap[i + 2] == 0xff)) {
-                    j = (symbol->bitmap[i] == 0) + (symbol->bitmap[i + 1] == 0) * 2 + (symbol->bitmap[i + 2] == 0) * 4;
-                    if (*e != colour[j]) {
-                        *row = r;
-                        *column = c;
-                        return 1 /*fail*/;
-                    }
-                    e++;
-                } else {
-                    sprintf(buf, "%02X%02X%02X", symbol->bitmap[i], symbol->bitmap[i + 1], symbol->bitmap[i + 2]);
-                    if (strncmp(buf, e, 6) != 0) {
-                        *row = r;
-                        *column = c;
-                        return 1 /*fail*/;
-                    }
-                    e += 6;
-                }
-            }
-        }
-    }
-
-    *row = r;
-    *column = c;
-    return e != ep || r != symbol->bitmap_height || c != symbol->bitmap_width ? 1 /*fail*/ : 0 /*success*/;
-}
-
+/* Does file exist? */
 int testUtilExists(const char *filename) {
     FILE *fp = fopen(filename, "r");
     if (fp == NULL) {
@@ -1385,6 +1381,7 @@ int testUtilExists(const char *filename) {
     return 1;
 }
 
+/* Does directory exist? (Windows compatibility) */
 int testUtilDirExists(const char *dirname) {
 #ifdef _WIN32
     DWORD dwAttrib = GetFileAttributes(dirname);
@@ -1394,7 +1391,7 @@ int testUtilDirExists(const char *dirname) {
 #endif
 }
 
-// Returns 0 if successful, non-zero if not
+/* Make a directory (Windows compatibility). Returns 0 if successful, non-zero if not */
 int testUtilMkDir(const char *dirname) {
 #ifdef _WIN32
     return CreateDirectory(dirname, NULL) == 0;
@@ -1403,7 +1400,7 @@ int testUtilMkDir(const char *dirname) {
 #endif
 }
 
-// Returns 0 if successful, non-zero if not
+/* Remove a directory (Windows compatibility). Returns 0 if successful, non-zero if not */
 int testUtilRmDir(const char *dirname) {
 #ifdef _WIN32
     return RemoveDirectory(dirname) == 0;
@@ -1412,6 +1409,7 @@ int testUtilRmDir(const char *dirname) {
 #endif
 }
 
+/* Rename a file (Windows compatibility). */
 int testUtilRename(const char *oldpath, const char *newpath) {
 #ifdef _MSVC
     int ret = remove(newpath);
@@ -1420,6 +1418,7 @@ int testUtilRename(const char *oldpath, const char *newpath) {
     return rename(oldpath, newpath);
 }
 
+/* Compare 2 PNG files */
 int testUtilCmpPngs(const char *png1, const char *png2) {
     int ret = -1;
 #ifdef NO_PNG
@@ -1446,7 +1445,7 @@ int testUtilCmpPngs(const char *png1, const char *png2) {
         return 3;
     }
 
-    png_ptr1 = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, NULL, NULL);
+    png_ptr1 = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp) NULL, NULL, NULL);
     if (!png_ptr1) {
         fclose(fp1);
         fclose(fp2);
@@ -1454,23 +1453,23 @@ int testUtilCmpPngs(const char *png1, const char *png2) {
     }
     info_ptr1 = png_create_info_struct(png_ptr1);
     if (!info_ptr1) {
-        png_destroy_read_struct(&png_ptr1, (png_infopp)NULL, (png_infopp)NULL);
+        png_destroy_read_struct(&png_ptr1, (png_infopp) NULL, (png_infopp) NULL);
         fclose(fp1);
         fclose(fp2);
         return 5;
     }
 
-    png_ptr2 = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, NULL, NULL);
+    png_ptr2 = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp) NULL, NULL, NULL);
     if (!png_ptr2) {
-        png_destroy_read_struct(&png_ptr1, &info_ptr1, (png_infopp)NULL);
+        png_destroy_read_struct(&png_ptr1, &info_ptr1, (png_infopp) NULL);
         fclose(fp1);
         fclose(fp2);
         return 6;
     }
     info_ptr2 = png_create_info_struct(png_ptr2);
     if (!info_ptr2) {
-        png_destroy_read_struct(&png_ptr1, &info_ptr1, (png_infopp)NULL);
-        png_destroy_read_struct(&png_ptr2, (png_infopp)NULL, (png_infopp)NULL);
+        png_destroy_read_struct(&png_ptr1, &info_ptr1, (png_infopp) NULL);
+        png_destroy_read_struct(&png_ptr2, (png_infopp) NULL, (png_infopp) NULL);
         fclose(fp1);
         fclose(fp2);
         return 7;
@@ -1483,8 +1482,8 @@ int testUtilCmpPngs(const char *png1, const char *png2) {
         if (row2) {
             free(row2);
         }
-        png_destroy_read_struct(&png_ptr1, &info_ptr1, (png_infopp)NULL);
-        png_destroy_read_struct(&png_ptr2, &info_ptr2, (png_infopp)NULL);
+        png_destroy_read_struct(&png_ptr1, &info_ptr1, (png_infopp) NULL);
+        png_destroy_read_struct(&png_ptr2, &info_ptr2, (png_infopp) NULL);
         fclose(fp1);
         fclose(fp2);
         return 8;
@@ -1496,8 +1495,8 @@ int testUtilCmpPngs(const char *png1, const char *png2) {
         if (row2) {
             free(row2);
         }
-        png_destroy_read_struct(&png_ptr1, &info_ptr1, (png_infopp)NULL);
-        png_destroy_read_struct(&png_ptr2, &info_ptr2, (png_infopp)NULL);
+        png_destroy_read_struct(&png_ptr1, &info_ptr1, (png_infopp) NULL);
+        png_destroy_read_struct(&png_ptr2, &info_ptr2, (png_infopp) NULL);
         fclose(fp1);
         fclose(fp2);
         return 9;
@@ -1516,8 +1515,8 @@ int testUtilCmpPngs(const char *png1, const char *png2) {
 
     if (width1 != width2 || height1 != height2) {
         printf("width1 %d, width2 %d, height1 %d, height2 %d\n", width1, width2, height1, height2);
-        png_destroy_read_struct(&png_ptr1, &info_ptr1, (png_infopp)NULL);
-        png_destroy_read_struct(&png_ptr2, &info_ptr2, (png_infopp)NULL);
+        png_destroy_read_struct(&png_ptr1, &info_ptr1, (png_infopp) NULL);
+        png_destroy_read_struct(&png_ptr2, &info_ptr2, (png_infopp) NULL);
         fclose(fp1);
         fclose(fp2);
         return 10;
@@ -1537,7 +1536,8 @@ int testUtilCmpPngs(const char *png1, const char *png2) {
     if (png_get_valid(png_ptr1, info_ptr1, PNG_INFO_tRNS)) {
         png_set_tRNS_to_alpha(png_ptr1);
     }
-    if (color_type1 == PNG_COLOR_TYPE_RGB || color_type1 == PNG_COLOR_TYPE_GRAY || color_type1 == PNG_COLOR_TYPE_PALETTE) {
+    if (color_type1 == PNG_COLOR_TYPE_RGB || color_type1 == PNG_COLOR_TYPE_GRAY
+            || color_type1 == PNG_COLOR_TYPE_PALETTE) {
         png_set_filler(png_ptr1, 0xFF, PNG_FILLER_AFTER);
     }
     if (color_type1 == PNG_COLOR_TYPE_GRAY || color_type1 == PNG_COLOR_TYPE_GRAY_ALPHA) {
@@ -1558,7 +1558,8 @@ int testUtilCmpPngs(const char *png1, const char *png2) {
     if (png_get_valid(png_ptr2, info_ptr2, PNG_INFO_tRNS)) {
         png_set_tRNS_to_alpha(png_ptr2);
     }
-    if (color_type2 == PNG_COLOR_TYPE_RGB || color_type2 == PNG_COLOR_TYPE_GRAY || color_type2 == PNG_COLOR_TYPE_PALETTE) {
+    if (color_type2 == PNG_COLOR_TYPE_RGB || color_type2 == PNG_COLOR_TYPE_GRAY
+            || color_type2 == PNG_COLOR_TYPE_PALETTE) {
         png_set_filler(png_ptr2, 0xFF, PNG_FILLER_AFTER);
     }
     if (color_type2 == PNG_COLOR_TYPE_GRAY || color_type2 == PNG_COLOR_TYPE_GRAY_ALPHA) {
@@ -1615,6 +1616,7 @@ int testUtilCmpPngs(const char *png1, const char *png2) {
     return ret;
 }
 
+/* Compare 2 TXT files */
 int testUtilCmpTxts(const char *txt1, const char *txt2) {
     int ret = -1;
     FILE *fp1;
@@ -1665,6 +1667,7 @@ int testUtilCmpTxts(const char *txt1, const char *txt2) {
     return ret;
 }
 
+/* Compare 2 binary files */
 int testUtilCmpBins(const char *bin1, const char *bin2) {
     int ret = -1;
     FILE *fp1;
@@ -1705,10 +1708,12 @@ int testUtilCmpBins(const char *bin1, const char *bin2) {
     return ret;
 }
 
+/* Compare 2 SVG files */
 int testUtilCmpSvgs(const char *svg1, const char *svg2) {
     return testUtilCmpTxts(svg1, svg2);
 }
 
+/* Compare 2 EPS files */
 int testUtilCmpEpss(const char *eps1, const char *eps2) {
     int ret = -1;
     FILE *fp1;
@@ -1733,8 +1738,10 @@ int testUtilCmpEpss(const char *eps1, const char *eps2) {
     if (fgets(buf1, sizeof(buf1), fp1) == NULL || strcmp(buf1, first_line) != 0
             || fgets(buf2, sizeof(buf2), fp2) == NULL || strcmp(buf2, first_line) != 0) {
         ret = 10;
-    } else if (fgets(buf1, sizeof(buf1), fp1) == NULL || strncmp(buf1, second_line_start, sizeof(second_line_start) - 1) != 0
-            || fgets(buf2, sizeof(buf2), fp2) == NULL || strncmp(buf2, second_line_start, sizeof(second_line_start) - 1) != 0) {
+    } else if (fgets(buf1, sizeof(buf1), fp1) == NULL
+            || strncmp(buf1, second_line_start, sizeof(second_line_start) - 1) != 0
+            || fgets(buf2, sizeof(buf2), fp2) == NULL
+            || strncmp(buf2, second_line_start, sizeof(second_line_start) - 1) != 0) {
         ret = 11;
     }
 
@@ -1780,10 +1787,12 @@ int testUtilCmpEpss(const char *eps1, const char *eps2) {
 #define DEV_NULL_STDERR "> /dev/null 2>&1"
 #endif
 
+/* Whether ImageMagick's identify utility available on system */
 int testUtilHaveIdentify() {
     return system("magick -version " DEV_NULL) == 0;
 }
 
+/* Check raster files */
 int testUtilVerifyIdentify(const char *filename, int debug) {
     char cmd[512 + 128];
 
@@ -1805,10 +1814,12 @@ int testUtilVerifyIdentify(const char *filename, int debug) {
     return system(cmd);
 }
 
+/* Whether Libre Office available on system */
 int testUtilHaveLibreOffice() {
     return system("libreoffice --version " DEV_NULL) == 0;
 }
 
+/* Check SVG files, very hacky to evoke. Will fail if Libre package that is not LibreOffice Draw is running */
 int testUtilVerifyLibreOffice(const char *filename, int debug) {
     char cmd[512 + 128];
     char svg[512];
@@ -1818,7 +1829,8 @@ int testUtilVerifyLibreOffice(const char *filename, int debug) {
     FILE *fp;
     int len;
 
-    /* Hack to read SVG produced by LibreOffice and search for 'x="-32767"' which indicates it didn't load barcode file */
+    /* Hack to read SVG produced by LibreOffice and search for 'x="-32767"' which indicates it didn't load barcode
+       file */
     if (strlen(filename) > 512) {
         return -1;
     }
@@ -1886,10 +1898,12 @@ int testUtilVerifyLibreOffice(const char *filename, int debug) {
 #define GS_FILENAME "gs"
 #endif
 
+/* Whether Ghostscript available on system */
 int testUtilHaveGhostscript() {
     return system(GS_FILENAME " -v " DEV_NULL) == 0;
 }
 
+/* Check EPS files */
 int testUtilVerifyGhostscript(const char *filename, int debug) {
     char cmd[512 + 128];
 
@@ -1897,7 +1911,8 @@ int testUtilVerifyGhostscript(const char *filename, int debug) {
         return -1;
     }
     if (debug & ZINT_DEBUG_TEST_PRINT) {
-        sprintf(cmd, GS_FILENAME " -dNOPAUSE -dBATCH -dNODISPLAY -q %s", filename); // Prints nothing of interest with or without -q unless bad
+        // Prints nothing of interest with or without -q unless bad
+        sprintf(cmd, GS_FILENAME " -dNOPAUSE -dBATCH -dNODISPLAY -q %s", filename);
         printf("%s\n", cmd);
     } else {
         sprintf(cmd, GS_FILENAME " -dNOPAUSE -dBATCH -dNODISPLAY -q %s", filename);
@@ -1906,12 +1921,13 @@ int testUtilVerifyGhostscript(const char *filename, int debug) {
     return system(cmd);
 }
 
-/* v.Nu https://github.com/validator/validator
- * Needs "$INSTALL_DIR/vnu-runtime-image/bin" in PATH */
+/* Whether vnu validator available on system. v.Nu https://github.com/validator/validator
+   Needs "$INSTALL_DIR/vnu-runtime-image/bin" in PATH */
 int testUtilHaveVnu() {
     return system("vnu --version " DEV_NULL_STDERR) == 0;
 }
 
+/* Check SVG files, very full but very slow */
 int testUtilVerifyVnu(const char *filename, int debug) {
     char buf[512 + 128];
 
@@ -1928,11 +1944,12 @@ int testUtilVerifyVnu(const char *filename, int debug) {
     return system(buf);
 }
 
-/* Requires libtiff 4.2.0 http://www.libtiff.org to be installed */
+/* Whether tiffinfo available on system. Requires libtiff 4.2.0 http://www.libtiff.org to be installed */
 int testUtilHaveTiffInfo() {
     return system("tiffinfo -h " DEV_NULL) == 0;
 }
 
+/* Check TIF files */
 int testUtilVerifyTiffInfo(const char *filename, int debug) {
     char cmd[512 + 128];
 
@@ -1948,7 +1965,9 @@ int testUtilVerifyTiffInfo(const char *filename, int debug) {
     return system(cmd);
 }
 
-static const char *testUtilBwippName(int index, const struct zint_symbol *symbol, int option_1, int option_2, int option_3, int debug, int *linear_row_height, int *gs1_cvt) {
+/* Map Zint symbology to BWIPP routine */
+static const char *testUtilBwippName(int index, const struct zint_symbol *symbol, int option_1, int option_2,
+                    int option_3, int debug, int *linear_row_height, int *gs1_cvt) {
     struct item {
         const char *name;
         int define;
@@ -2116,7 +2135,8 @@ static const char *testUtilBwippName(int index, const struct zint_symbol *symbol
         fprintf(stderr, "testUtilBwippName: unknown symbology (%d)\n", symbology);
         abort();
     }
-    if (data[symbology].val != symbology || (data[symbology].define != -1 && data[symbology].define != symbology)) { // Self-check
+    // Self-check
+    if (data[symbology].val != symbology || (data[symbology].define != -1 && data[symbology].define != symbology)) {
         fprintf(stderr, "testUtilBwippName: data table out of sync (%d)\n", symbology);
         abort();
     }
@@ -2129,7 +2149,8 @@ static const char *testUtilBwippName(int index, const struct zint_symbol *symbol
     if ((option_1 != -1 && !data[symbology].can_option_1) || (option_2 != -1 && !data[symbology].can_option_2)
              || (option_3 != -1 && !data[symbology].can_option_3)) {
         if (debug & ZINT_DEBUG_TEST_PRINT) {
-            printf("i:%d %s not BWIPP compatible, options not supported, option_1 %d, option_2 %d, option_3 %d\n", index, testUtilBarcodeName(symbology), option_1, option_2, option_3);
+            printf("i:%d %s not BWIPP compatible, options not supported, option_1 %d, option_2 %d, option_3 %d\n",
+                    index, testUtilBarcodeName(symbology), option_1, option_2, option_3);
         }
         return NULL;
     }
@@ -2137,14 +2158,16 @@ static const char *testUtilBwippName(int index, const struct zint_symbol *symbol
     if (symbology == BARCODE_CODE11) {
         if (option_2 != 1 && option_2 != 2) { /* 2 check digits (Zint default) not supported */
             if (debug & ZINT_DEBUG_TEST_PRINT) {
-                printf("i:%d %s not BWIPP compatible, 2 check digits not supported, option_1 %d, option_2 %d\n", index, testUtilBarcodeName(symbology), option_1, option_2);
+                printf("i:%d %s not BWIPP compatible, 2 check digits not supported, option_1 %d, option_2 %d\n",
+                        index, testUtilBarcodeName(symbology), option_1, option_2);
             }
             return NULL;
         }
     } else if (symbology == BARCODE_CODABLOCKF || symbology == BARCODE_HIBC_BLOCKF) {
         if (option_1 == 1) { /* Single row i.e. CODE128 not supported */
             if (debug & ZINT_DEBUG_TEST_PRINT) {
-                printf("i:%d %s not BWIPP compatible, single row not supported, option_1 %d\n", index, testUtilBarcodeName(symbology), option_1);
+                printf("i:%d %s not BWIPP compatible, single row not supported, option_1 %d\n",
+                        index, testUtilBarcodeName(symbology), option_1);
             }
             return NULL;
         }
@@ -2164,7 +2187,8 @@ static const char *testUtilBwippName(int index, const struct zint_symbol *symbol
             return "gs1datamatrix";
         } else if (symbology == BARCODE_AZTEC) {
             if (debug & ZINT_DEBUG_TEST_PRINT) {
-                printf("i:%d %s not BWIPP compatible, GS1_MODE not supported\n", index, testUtilBarcodeName(symbology));
+                printf("i:%d %s not BWIPP compatible, GS1_MODE not supported\n",
+                        index, testUtilBarcodeName(symbology));
             }
             return NULL;
         } else if (symbology == BARCODE_DOTCODE) {
@@ -2178,10 +2202,13 @@ static const char *testUtilBwippName(int index, const struct zint_symbol *symbol
     return data[symbology].name;
 }
 
-int testUtilCanBwipp(int index, const struct zint_symbol *symbol, int option_1, int option_2, int option_3, int debug) {
+/* Whether can use BWIPP to check a symbology with given options */
+int testUtilCanBwipp(int index, const struct zint_symbol *symbol, int option_1, int option_2, int option_3,
+            int debug) {
     return testUtilBwippName(index, symbol, option_1, option_2, option_3, debug, NULL, NULL) != NULL;
 }
 
+/* Convert Zint GS1 and add-on format to BWIPP's */
 static void testUtilBwippCvtGS1Data(char *bwipp_data, int upcean, int *addon_posn) {
     char *b;
     int pipe = 0;
@@ -2202,7 +2229,9 @@ static void testUtilBwippCvtGS1Data(char *bwipp_data, int upcean, int *addon_pos
     }
 }
 
-static char *testUtilBwippEscape(char *bwipp_data, int bwipp_data_size, const char *data, int length, int zint_escape_mode, int eci, int *parse, int *parsefnc) {
+/* Convert data to Ghostscript format for passing to bwipp_dump.ps */
+static char *testUtilBwippEscape(char *bwipp_data, int bwipp_data_size, const char *data, int length,
+                int zint_escape_mode, int eci, int *parse, int *parsefnc) {
     char *b = bwipp_data;
     char *be = b + bwipp_data_size;
     unsigned char *d = (unsigned char *) data;
@@ -2269,10 +2298,11 @@ static char *testUtilBwippEscape(char *bwipp_data, int bwipp_data_size, const ch
     return bwipp_data;
 }
 
+/* Convert ISBN to BWIPP format */
 static void testUtilISBNHyphenate(char *bwipp_data, int addon_posn) {
     /* Hack in 4 hyphens in fixed format, wrong for many ISBNs */
     char temp[13 + 4 + 1 + 5 + 1];
-    int len = strlen(bwipp_data);
+    int len = (int) strlen(bwipp_data);
     int i, j;
 
     if (len < 13 || (addon_posn && addon_posn < 13 ) || len >= (int) sizeof(temp)) {
@@ -2289,16 +2319,23 @@ static void testUtilISBNHyphenate(char *bwipp_data, int addon_posn) {
 
 #define GS_INITIAL_LEN  35 /* Length of cmd up to -q */
 
-int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int option_2, int option_3, const char *data, int length, const char *primary, char *buffer, int buffer_size) {
+/* Create bwipp_dump.ps command and run */
+int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int option_2, int option_3,
+            const char *data, int length, const char *primary, char *buffer, int buffer_size) {
     const char *cmd_fmt = "gs -dNOPAUSE -dBATCH -dNODISPLAY -q -sb=%s -sd='%s' backend/tests/tools/bwipp_dump.ps";
-    const char *cmd_opts_fmt = "gs -dNOPAUSE -dBATCH -dNODISPLAY -q -sb=%s -sd='%s' -so='%s' backend/tests/tools/bwipp_dump.ps";
-    const char *cmd_fmt2 = "gs -dNOPAUSE -dBATCH -dNODISPLAY -q -sb=%s -sd='%.2043s' -sd2='%s' backend/tests/tools/bwipp_dump.ps"; // If data > 2K
-    const char *cmd_opts_fmt2 = "gs -dNOPAUSE -dBATCH -dNODISPLAY -q -sb=%s -sd='%.2043s' -sd2='%s' -so='%s' backend/tests/tools/bwipp_dump.ps";
+    const char *cmd_opts_fmt = "gs -dNOPAUSE -dBATCH -dNODISPLAY -q -sb=%s -sd='%s' -so='%s'"
+                                " backend/tests/tools/bwipp_dump.ps";
+    // If data > 2K
+    const char *cmd_fmt2 = "gs -dNOPAUSE -dBATCH -dNODISPLAY -q -sb=%s -sd='%.2043s' -sd2='%s'"
+                                " backend/tests/tools/bwipp_dump.ps";
+    const char *cmd_opts_fmt2 = "gs -dNOPAUSE -dBATCH -dNODISPLAY -q -sb=%s -sd='%.2043s' -sd2='%s' -so='%s'"
+                                " backend/tests/tools/bwipp_dump.ps";
 
     int symbology = symbol->symbology;
     int data_len = length == -1 ? (int) strlen(data) : length;
     int primary_len = primary ? (int) strlen(primary) : 0;
-    int max_data_len = 4 + primary_len + 1 + 1 + data_len * 4 + 64; /* 4 AI prefix + primary + '|' + leading zero + escaped data + fudge */
+    /* 4 AI prefix + primary + '|' + leading zero + escaped data + fudge */
+    int max_data_len = 4 + primary_len + 1 + 1 + data_len * 4 + 64;
 
     int eci_length = get_eci_length(symbol->eci, (const unsigned char *) data, data_len);
     char *converted = (char *) testutil_alloca(eci_length + 1);
@@ -2333,7 +2370,8 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
 
     bwipp_barcode = testUtilBwippName(index, symbol, option_1, option_2, option_3, 0, &linear_row_height, &gs1_cvt);
     if (!bwipp_barcode) {
-        fprintf(stderr, "i:%d testUtilBwipp: no mapping for %s, option_1 %d, option_2 %d, option_3 %d\n", index, testUtilBarcodeName(symbology), option_1, option_2, option_3);
+        fprintf(stderr, "i:%d testUtilBwipp: no mapping for %s, option_1 %d, option_2 %d, option_3 %d\n",
+                index, testUtilBarcodeName(symbology), option_1, option_2, option_3);
         return -1;
     }
 
@@ -2343,21 +2381,25 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
         } else {
             bwipp_row_height[r] = symbol->row_height[r] ? symbol->row_height[r] : linear_row_height;
         }
-        //fprintf(stderr, "bwipp_row_height[%d] %d, symbol->row_height[%d] %d\n", r, bwipp_row_height[r], r, symbol->row_height[r]);
+        /*fprintf(stderr, "bwipp_row_height[%d] %d, symbol->row_height[%d] %d\n",
+                    r, bwipp_row_height[r], r, symbol->row_height[r]);*/
     }
 
-    if ((symbol->input_mode & 0x07) == UNICODE_MODE && ZBarcode_Cap(symbology, ZINT_CAP_ECI) && is_eci_convertible(symbol->eci)) {
+    if ((symbol->input_mode & 0x07) == UNICODE_MODE && ZBarcode_Cap(symbology, ZINT_CAP_ECI)
+            && is_eci_convertible(symbol->eci)) {
         if (utf8_to_eci(symbol->eci, (const unsigned char *) data, (unsigned char *) converted, &data_len) == 0) {
             eci = symbol->eci;
         } else {
             if (symbol->eci != 0) {
                 eci = get_best_eci((const unsigned char *) data, data_len);
                 if (utf8_to_eci(eci, (const unsigned char *) data, (unsigned char *) converted, &data_len) != 0) {
-                    fprintf(stderr, "i:%d testUtilBwipp: failed to convert Unicode data for %s\n", index, testUtilBarcodeName(symbology));
+                    fprintf(stderr, "i:%d testUtilBwipp: failed to convert Unicode data for %s\n",
+                            index, testUtilBarcodeName(symbology));
                     return -1;
                 }
             } else {
-                fprintf(stderr, "i:%d testUtilBwipp: failed to convert Unicode data for %s\n", index, testUtilBarcodeName(symbology));
+                fprintf(stderr, "i:%d testUtilBwipp: failed to convert Unicode data for %s\n",
+                        index, testUtilBarcodeName(symbology));
                 return -1;
             }
         }
@@ -2384,18 +2426,21 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                 bwipp_barcode = "ean8composite";
             }
             if (addon_posn) {
-                sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%saddongap=%d", strlen(bwipp_opts_buf) ? " " : "", option_2 > 0 ? option_2 : upca ? 9 : 7);
+                sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%saddongap=%d",
+                        strlen(bwipp_opts_buf) ? " " : "", option_2 > 0 ? option_2 : upca ? 9 : 7);
                 bwipp_opts = bwipp_opts_buf;
             }
             bwipp_row_height[symbol->rows - 1] = 72;
         }
 
         if (option_1 > 0) {
-            sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sccversion=%c", strlen(bwipp_opts_buf) ? " " : "", option_1 == 1 ? 'a' : option_1 == 2 ? 'b' : 'c');
+            sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sccversion=%c",
+                    strlen(bwipp_opts_buf) ? " " : "", option_1 == 1 ? 'a' : option_1 == 2 ? 'b' : 'c');
             bwipp_opts = bwipp_opts_buf;
         }
         if (option_2 > 0) {
-            sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%ssegments=%d", strlen(bwipp_opts_buf) ? " " : "", option_2 * 2);
+            sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%ssegments=%d",
+                    strlen(bwipp_opts_buf) ? " " : "", option_2 * 2);
             bwipp_opts = bwipp_opts_buf;
         }
     } else {
@@ -2407,51 +2452,58 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
             testUtilBwippCvtGS1Data(bwipp_data, upcean, &addon_posn);
 
             if (upcean) {
-                if ((symbology == BARCODE_EANX || symbology == BARCODE_EANX_CHK) && (data_len <= 8 || (addon_posn && addon_posn <= 8))) {
+                if ((symbology == BARCODE_EANX || symbology == BARCODE_EANX_CHK)
+                        && (data_len <= 8 || (addon_posn && addon_posn <= 8))) {
                     bwipp_barcode = data_len <= 3 ? "ean2" : data_len <= 5 ? "ean5" : "ean8";
                 }
                 if (symbology == BARCODE_ISBNX) {
                     testUtilISBNHyphenate(bwipp_data, addon_posn);
                 }
                 if (addon_posn) {
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%saddongap=%d", strlen(bwipp_opts_buf) ? " " : "", option_2 > 0 ? option_2 : upca ? 9 : 7);
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%saddongap=%d",
+                            strlen(bwipp_opts_buf) ? " " : "", option_2 > 0 ? option_2 : upca ? 9 : 7);
                     bwipp_opts = bwipp_opts_buf;
                 }
             }
 
             if (option_2 > 0) {
                 if (symbology == BARCODE_DBAR_EXP || symbology == BARCODE_DBAR_EXPSTK) {
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%ssegments=%d", strlen(bwipp_opts_buf) ? " " : "", option_2 * 2);
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%ssegments=%d",
+                            strlen(bwipp_opts_buf) ? " " : "", option_2 * 2);
                     bwipp_opts = bwipp_opts_buf;
                 }
             }
         } else {
-            if (testUtilBwippEscape(bwipp_data, bwipp_data_size, data, data_len, symbol->input_mode & ESCAPE_MODE, eci, &parse, &parsefnc) == NULL) {
+            if (testUtilBwippEscape(bwipp_data, bwipp_data_size, data, data_len, symbol->input_mode & ESCAPE_MODE,
+                    eci, &parse, &parsefnc) == NULL) {
                 return -1;
             }
             if (parse) {
-                sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sparse", strlen(bwipp_opts_buf) ? " " : "");
+                sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sparse", strlen(bwipp_opts_buf) ? " " : "");
                 bwipp_opts = bwipp_opts_buf;
             }
             if (parsefnc) {
-                sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sparsefnc", strlen(bwipp_opts_buf) ? " " : "");
+                sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sparsefnc",
+                        strlen(bwipp_opts_buf) ? " " : "");
                 bwipp_opts = bwipp_opts_buf;
             }
 
             if (symbology == BARCODE_C25STANDARD || symbology == BARCODE_C25INTER || symbology == BARCODE_C25IATA
                     || symbology == BARCODE_C25LOGIC || symbology == BARCODE_C25IND) {
                 if (option_2 == 1 || option_2 == 2) { // Add check digit without or with HRT suppression
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sincludecheck", strlen(bwipp_opts_buf) ? " " : "");
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sincludecheck",
+                            strlen(bwipp_opts_buf) ? " " : "");
                     bwipp_opts = bwipp_opts_buf;
                 }
             } else if (symbology == BARCODE_CODE93) {
-                sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sincludecheck", strlen(bwipp_opts_buf) ? " " : "");
+                sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sincludecheck",
+                        strlen(bwipp_opts_buf) ? " " : "");
                 if (parse) {
                     bwipp_barcode = "code93ext";
                 }
                 bwipp_opts = bwipp_opts_buf;
             } else if (symbology == BARCODE_PZN) {
-                sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%spzn8", strlen(bwipp_opts_buf) ? " " : "");
+                sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%spzn8", strlen(bwipp_opts_buf) ? " " : "");
                 bwipp_opts = bwipp_opts_buf;
             } else if (symbology == BARCODE_TELEPEN_NUM) {
                 if (data_len & 1) { // Add leading zero
@@ -2459,30 +2511,36 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                     *bwipp_data = '0';
                 }
             } else if (symbology == BARCODE_CODABLOCKF || symbology == BARCODE_HIBC_BLOCKF) {
-                sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%ssepheight=0", strlen(bwipp_opts_buf) ? " " : "");
+                sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%ssepheight=0", strlen(bwipp_opts_buf) ? " " : "");
                 if (option_1 > 0) {
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%srows=%d", strlen(bwipp_opts_buf) ? " " : "", option_1);
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%srows=%d",
+                            strlen(bwipp_opts_buf) ? " " : "", option_1);
                 }
                 if (option_2 > 0) {
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%scolumns=%d", strlen(bwipp_opts_buf) ? " " : "", option_2 - 5);
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%scolumns=%d",
+                            strlen(bwipp_opts_buf) ? " " : "", option_2 - 5);
                 } else {
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%scolumns=%d", strlen(bwipp_opts_buf) ? " " : "", (symbol->width - 57) / 11);
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%scolumns=%d",
+                            strlen(bwipp_opts_buf) ? " " : "", (symbol->width - 57) / 11);
                 }
                 bwipp_opts = bwipp_opts_buf;
-            } else if (symbology == BARCODE_CODE11 || symbology == BARCODE_CODE39 || symbology == BARCODE_EXCODE39 || symbology == BARCODE_LOGMARS || symbology == BARCODE_CODABAR) {
+            } else if (symbology == BARCODE_CODE11 || symbology == BARCODE_CODE39 || symbology == BARCODE_EXCODE39
+                        || symbology == BARCODE_LOGMARS || symbology == BARCODE_CODABAR) {
                 if (option_2 > 0) {
                     if (option_2 == 1) {
-                        sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sincludecheck", strlen(bwipp_opts_buf) ? " " : "");
+                        sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sincludecheck",
+                                strlen(bwipp_opts_buf) ? " " : "");
                     }
                     bwipp_opts = bwipp_opts_buf; /* Set always as option_2 == 2 is bwipp default */
                 }
             } else if (symbology == BARCODE_PLESSEY) {
-                sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sincludecheck", strlen(bwipp_opts_buf) ? " " : "");
+                sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sincludecheck", strlen(bwipp_opts_buf) ? " " : "");
                 bwipp_opts = bwipp_opts_buf;
             } else if (symbology == BARCODE_MSI_PLESSEY) {
                 if (option_2 > 0) {
                     const char *checktype = NULL;
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sincludecheck", strlen(bwipp_opts_buf) ? " " : "");
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sincludecheck",
+                            strlen(bwipp_opts_buf) ? " " : "");
 
                     if (option_2 >= 11 && option_2 <= 16) {
                         option_2 -= 10; /* Remove no-check indicator */
@@ -2499,23 +2557,28 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                         checktype = "ncrmod1110 badmod11";
                     }
                     if (checktype) {
-                        sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%schecktype=%s", strlen(bwipp_opts_buf) ? " " : "", checktype);
+                        sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%schecktype=%s",
+                                strlen(bwipp_opts_buf) ? " " : "", checktype);
                     }
                     bwipp_opts = bwipp_opts_buf;
                 }
             } else if (symbology == BARCODE_PDF417 || symbology == BARCODE_PDF417COMP || symbology == BARCODE_HIBC_PDF
-                    || symbology == BARCODE_MICROPDF417 || symbology == BARCODE_HIBC_MICPDF) {
+                        || symbology == BARCODE_MICROPDF417 || symbology == BARCODE_HIBC_MICPDF) {
                 for (r = 0; r < symbol->rows; r++) bwipp_row_height[r] = 1; /* Change from 3 */
                 if (option_1 >= 0) {
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%seclevel=%d", strlen(bwipp_opts_buf) ? " " : "", option_1);
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%seclevel=%d",
+                            strlen(bwipp_opts_buf) ? " " : "", option_1);
                     bwipp_opts = bwipp_opts_buf;
                 }
                 if (option_2 > 0) {
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%scolumns=%d", strlen(bwipp_opts_buf) ? " " : "", option_2);
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%scolumns=%d",
+                            strlen(bwipp_opts_buf) ? " " : "", option_2);
                     bwipp_opts = bwipp_opts_buf;
                 }
-            } else if (symbology == BARCODE_POSTNET || symbology == BARCODE_PLANET || symbology == BARCODE_RM4SCC || symbology == BARCODE_JAPANPOST || symbology == BARCODE_KIX
-                    || symbology == BARCODE_DAFT || symbology == BARCODE_USPS_IMAIL || symbology == BARCODE_AUSPOST || symbology == BARCODE_PHARMA_TWO) {
+            } else if (symbology == BARCODE_POSTNET || symbology == BARCODE_PLANET || symbology == BARCODE_RM4SCC
+                        || symbology == BARCODE_JAPANPOST || symbology == BARCODE_KIX || symbology == BARCODE_DAFT
+                        || symbology == BARCODE_USPS_IMAIL || symbology == BARCODE_AUSPOST
+                        || symbology == BARCODE_PHARMA_TWO) {
                 for (r = 0; r < symbol->rows; r++) bwipp_row_height[r] = 1; /* Zap */
                 if (symbology == BARCODE_KIX) {
                     to_upper((unsigned char *) bwipp_data);
@@ -2531,13 +2594,15 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                     } else if (data_len == 13 || data_len == 16) {
                         prefix = "59";
                         if (data_len == 16) {
-                            sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%scustinfoenc=numeric", strlen(bwipp_opts_buf) ? " " : "");
+                            sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%scustinfoenc=numeric",
+                                    strlen(bwipp_opts_buf) ? " " : "");
                             bwipp_opts = bwipp_opts_buf;
                         }
                     } else {
                         prefix = "62";
                         if (data_len == 23) {
-                            sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%scustinfoenc=numeric", strlen(bwipp_opts_buf) ? " " : "");
+                            sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%scustinfoenc=numeric",
+                                    strlen(bwipp_opts_buf) ? " " : "");
                             bwipp_opts = bwipp_opts_buf;
                         }
                     }
@@ -2548,7 +2613,7 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                 strcpy(bwipp_data, "fima");
                 bwipp_data[3] = data[0] - 'A' + 'a';
             } else if (symbology == BARCODE_CODE16K || symbology == BARCODE_CODE49) {
-                sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%ssepheight=0", strlen(bwipp_opts_buf) ? " " : "");
+                sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%ssepheight=0", strlen(bwipp_opts_buf) ? " " : "");
                 bwipp_opts = bwipp_opts_buf;
             } else if (symbology == BARCODE_AZTEC || symbology == BARCODE_HIBC_AZTEC) {
                 int compact = 0, full = 0;
@@ -2563,7 +2628,8 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                     } else {
                         eclevel = 50;
                     }
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%seclevel=%d", strlen(bwipp_opts_buf) ? " " : "", eclevel);
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%seclevel=%d",
+                            strlen(bwipp_opts_buf) ? " " : "", eclevel);
                     bwipp_opts = bwipp_opts_buf;
                 }
                 if (option_2 >= 1) {
@@ -2575,37 +2641,43 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                         layers = option_2 - 4;
                         full = layers <= 4;
                     }
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%slayers=%d", strlen(bwipp_opts_buf) ? " " : "", layers);
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%slayers=%d",
+                            strlen(bwipp_opts_buf) ? " " : "", layers);
                     bwipp_opts = bwipp_opts_buf;
                 }
                 if (symbol->output_options & READER_INIT) {
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sreaderinit", strlen(bwipp_opts_buf) ? " " : "");
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sreaderinit",
+                            strlen(bwipp_opts_buf) ? " " : "");
                     bwipp_opts = bwipp_opts_buf;
                 }
                 if (symbology == BARCODE_HIBC_AZTEC) {
                     compact = 1;
                 }
                 if (compact || full) {
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sformat=%s", strlen(bwipp_opts_buf) ? " " : "", compact ? "compact" : "full");
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sformat=%s",
+                            strlen(bwipp_opts_buf) ? " " : "", compact ? "compact" : "full");
                     bwipp_opts = bwipp_opts_buf;
                 }
             } else if (symbology == BARCODE_CODEONE) {
                 if ((symbol->input_mode & 0x07) == GS1_MODE) { /* Hack pseudo-GS1 support */
                     int last_ai, ai_latch = 0;
-                    for (i = 0, j = 0, len = (int) strlen(bwipp_data); i <= len; i++) { /* Reduce square brackets (include NUL) */
+                    /* Reduce square brackets (include NUL) */
+                    for (i = 0, j = 0, len = (int) strlen(bwipp_data); i <= len; i++) {
                         if (bwipp_data[i] == obracket) {
                             if (ai_latch == 0) {
                                 bwipp_data[j++] = '[';
                             }
                             last_ai = atoi(bwipp_data + i + 1);
-                            if ((last_ai >= 0 && last_ai <= 4) || (last_ai >= 11 && last_ai <= 20) || last_ai == 23 || (last_ai >= 31 && last_ai <= 36) || last_ai == 41) {
+                            if ((last_ai >= 0 && last_ai <= 4) || (last_ai >= 11 && last_ai <= 20) || last_ai == 23
+                                    || (last_ai >= 31 && last_ai <= 36) || last_ai == 41) {
                                 ai_latch = 1;
                             }
                         } else if (bwipp_data[i] != cbracket) {
                             bwipp_data[j++] = bwipp_data[i];
                         }
                     }
-                    for (len = (int) strlen(bwipp_data), i = len - 1; i >= 0; i--) { /* Replace square brackets with ^FNC1 */
+                    /* Replace square brackets with ^FNC1 */
+                    for (len = (int) strlen(bwipp_data), i = len - 1; i >= 0; i--) {
                         if (bwipp_data[i] == '[') {
                             memmove(bwipp_data + i + 5, bwipp_data + i + 1, len - i);
                             memcpy(bwipp_data + i, "^FNC1", 5);
@@ -2613,7 +2685,8 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                         }
                     }
                     if (symbol->eci == 0) { /* If not already done for ECI */
-                        sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sparsefnc", strlen(bwipp_opts_buf) ? " " : "");
+                        sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sparsefnc",
+                                strlen(bwipp_opts_buf) ? " " : "");
                         bwipp_opts = bwipp_opts_buf;
                     }
                 }
@@ -2623,11 +2696,13 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                     if (option_2 == 9) {
                         codeone_version = length <= 6 ? "S-10" : length <= 12 ? "S-20" : "S-30";
                     } else if (option_2 == 10) {
-                        codeone_version = length <= 22 ? "T-16" : length <= 34 ? "T-32" : "T-48"; // TODO: Properly allow for different T sizes
+                        // TODO: Properly allow for different T sizes
+                        codeone_version = length <= 22 ? "T-16" : length <= 34 ? "T-32" : "T-48";
                     } else {
                         codeone_version = codeone_versions[option_2 - 1];
                     }
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sversion=%s", strlen(bwipp_opts_buf) ? " " : "", codeone_version);
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sversion=%s",
+                            strlen(bwipp_opts_buf) ? " " : "", codeone_version);
                     bwipp_opts = bwipp_opts_buf;
                 }
             } else if (symbology == BARCODE_MAXICODE) {
@@ -2638,7 +2713,8 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                         mode = 4;
                     } else {
                         for (i = 0; i < primary_len - 6; i++) {
-                            if (((symbol->primary[i] < '0') || (symbol->primary[i] > '9')) && (symbol->primary[i] != ' ')) {
+                            if (((symbol->primary[i] < '0') || (symbol->primary[i] > '9'))
+                                    && (symbol->primary[i] != ' ')) {
                                 mode = 3;
                                 break;
                             }
@@ -2646,7 +2722,8 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                     }
                 }
                 if (mode > 0) {
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%smode=%d", strlen(bwipp_opts_buf) ? " " : "", mode);
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%smode=%d",
+                            strlen(bwipp_opts_buf) ? " " : "", mode);
                     bwipp_opts = bwipp_opts_buf;
                 }
                 if (primary_len) {
@@ -2669,7 +2746,8 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                             postcode[i] = ' ';
                         }
                     }
-                    sprintf(prefix_buf, "%s^029%.3s^029%.3s^029", postcode, primary + primary_len - 6, primary + primary_len - 3);
+                    sprintf(prefix_buf, "%s^029%.3s^029%.3s^029",
+                            postcode, primary + primary_len - 6, primary + primary_len - 3);
                     prefix_len = (int) strlen(prefix_buf);
                     if (have_scm) {
                         memmove(bwipp_data + 15 + prefix_len, bwipp_data, strlen(bwipp_data) - 15 + 1);
@@ -2679,7 +2757,8 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                         memcpy(bwipp_data, prefix_buf, prefix_len);
                     }
                     if (!parse) {
-                        sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sparse", strlen(bwipp_opts_buf) ? " " : "");
+                        sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sparse",
+                                strlen(bwipp_opts_buf) ? " " : "");
                         bwipp_opts = bwipp_opts_buf;
                         parse = 1;
                     }
@@ -2690,7 +2769,8 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
                     memmove(bwipp_data + 15, bwipp_data, strlen(bwipp_data) + 1);
                     memcpy(bwipp_data, scm_vv_buf, 15);
                     if (!parse) {
-                        sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sparse", strlen(bwipp_opts_buf) ? " " : "");
+                        sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sparse",
+                                strlen(bwipp_opts_buf) ? " " : "");
                         bwipp_opts = bwipp_opts_buf;
                         parse = 1;
                     }
@@ -2705,24 +2785,26 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
             (void)isDMRE; (void)text_value; (void)text_shift; (void)c40_value; (void)c40_shift;
 
             if (symbol->output_options & GS1_GS_SEPARATOR) {
-                sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sgssep", strlen(bwipp_opts_buf) ? " " : "");
+                sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sgssep", strlen(bwipp_opts_buf) ? " " : "");
                 bwipp_opts = bwipp_opts_buf;
             }
             if (option_2 >= 1 && option_2 <= (int) sizeof(intsymbol)) {
                 int idx = intsymbol[option_2 - 1];
-                sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%srows=%d columns=%d", strlen(bwipp_opts_buf) ? " " : "", matrixH[idx], matrixW[idx]);
+                sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%srows=%d columns=%d",
+                        strlen(bwipp_opts_buf) ? " " : "", matrixH[idx], matrixW[idx]);
                 bwipp_opts = bwipp_opts_buf;
                 if (option_2 >= 31) {
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sdmre", strlen(bwipp_opts_buf) ? " " : "");
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sdmre", strlen(bwipp_opts_buf) ? " " : "");
                     added_dmre = 1;
                 }
             }
             if (option_3 != DM_SQUARE && symbol->width != symbol->height) {
                 if (option_3 == DM_DMRE && !added_dmre) {
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sdmre", strlen(bwipp_opts_buf) ? " " : "");
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sdmre", strlen(bwipp_opts_buf) ? " " : "");
                     added_dmre = 1;
                 }
-                sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%sformat=rectangle", strlen(bwipp_opts_buf) ? " " : "");
+                sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%sformat=rectangle",
+                        strlen(bwipp_opts_buf) ? " " : "");
                 bwipp_opts = bwipp_opts_buf;
             }
             if (option_3 != -1) {
@@ -2730,13 +2812,15 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
             }
         } else if (symbology == BARCODE_DOTCODE) {
             if (option_2 > 0) {
-                sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%scolumns=%d", strlen(bwipp_opts_buf) ? " " : "", symbol->option_2);
+                sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%scolumns=%d",
+                        strlen(bwipp_opts_buf) ? " " : "", symbol->option_2);
                 bwipp_opts = bwipp_opts_buf;
             }
             if (option_3 != -1) {
                 user_mask = (option_3 >> 8) & 0x0F; /* User mask is pattern + 1, so >= 1 and <= 8 */
                 if (user_mask >= 1 && user_mask <= 8) {
-                    sprintf(bwipp_opts_buf + (int) strlen(bwipp_opts_buf), "%smask=%d", strlen(bwipp_opts_buf) ? " " : "", (user_mask - 1) % 4);
+                    sprintf(bwipp_opts_buf + strlen(bwipp_opts_buf), "%smask=%d",
+                            strlen(bwipp_opts_buf) ? " " : "", (user_mask - 1) % 4);
                     bwipp_opts = bwipp_opts_buf;
                 }
             }
@@ -2744,7 +2828,9 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
     }
 
     if ((option_1 != -1 || option_2 != -1 || option_3 != -1) && !bwipp_opts) {
-        fprintf(stderr, "i:%d testUtilBwipp: no BWIPP options set option_1 %d, option_2 %d, option_3 %d for symbology %s\n", index, option_1, option_2, option_3, testUtilBarcodeName(symbology));
+        fprintf(stderr,
+                "i:%d testUtilBwipp: no BWIPP options set option_1 %d, option_2 %d, option_3 %d for symbology %s\n",
+                index, option_1, option_2, option_3, testUtilBarcodeName(symbology));
         return -1;
     }
 
@@ -2769,14 +2855,16 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
         memmove(cmd + GS_INITIAL_LEN + sizeof(adj), cmd + GS_INITIAL_LEN, strlen(cmd) + 1 - GS_INITIAL_LEN);
         memcpy(cmd + GS_INITIAL_LEN, adj, sizeof(adj));
     }
-    if (symbology == BARCODE_CODE11 || symbology == BARCODE_CODE39 || symbology == BARCODE_EXCODE39 || symbology == BARCODE_CODABAR
-            || symbology == BARCODE_PHARMA || symbology == BARCODE_PZN || symbology == BARCODE_CODE32 || symbology == BARCODE_VIN) {
+    if (symbology == BARCODE_CODE11 || symbology == BARCODE_CODE39 || symbology == BARCODE_EXCODE39
+            || symbology == BARCODE_CODABAR || symbology == BARCODE_PHARMA || symbology == BARCODE_PZN
+            || symbology == BARCODE_CODE32 || symbology == BARCODE_VIN) {
         /* Ratio 3 width bar/space -> 2 width */
         char adj[8] = " -sr=0.6";
         memmove(cmd + GS_INITIAL_LEN + sizeof(adj), cmd + GS_INITIAL_LEN, strlen(cmd) + 1 - GS_INITIAL_LEN);
         memcpy(cmd + GS_INITIAL_LEN, adj, sizeof(adj));
     }
-    if (symbology == BARCODE_C25INTER || symbology == BARCODE_DPLEIT || symbology == BARCODE_DPIDENT || symbology == BARCODE_ITF14) {
+    if (symbology == BARCODE_C25INTER || symbology == BARCODE_DPLEIT || symbology == BARCODE_DPIDENT
+            || symbology == BARCODE_ITF14) {
         /* Ratio 2 width bar/space -> 3 width */
         char adj[8] = " -sr=1.3";
         memmove(cmd + GS_INITIAL_LEN + sizeof(adj), cmd + GS_INITIAL_LEN, strlen(cmd) + 1 - GS_INITIAL_LEN);
@@ -2794,10 +2882,11 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
         memmove(cmd + GS_INITIAL_LEN + sizeof(adj), cmd + GS_INITIAL_LEN, strlen(cmd) + 1 - GS_INITIAL_LEN);
         memcpy(cmd + GS_INITIAL_LEN, adj, sizeof(adj));
     }
-    if (symbology == BARCODE_CODE11 || symbology == BARCODE_CODE39 || symbology == BARCODE_EXCODE39 || symbology == BARCODE_HIBC_39
-            || symbology == BARCODE_LOGMARS || symbology == BARCODE_PHARMA || symbology == BARCODE_PZN || symbology == BARCODE_CODE32 || symbology == BARCODE_VIN
-            || symbology == BARCODE_C25INTER || symbology == BARCODE_DPLEIT || symbology == BARCODE_DPIDENT || symbology == BARCODE_ITF14
-            || symbology == BARCODE_PHARMA_TWO) {
+    if (symbology == BARCODE_CODE11 || symbology == BARCODE_CODE39 || symbology == BARCODE_EXCODE39
+            || symbology == BARCODE_HIBC_39 || symbology == BARCODE_LOGMARS || symbology == BARCODE_PHARMA
+            || symbology == BARCODE_PZN || symbology == BARCODE_CODE32 || symbology == BARCODE_VIN
+            || symbology == BARCODE_C25INTER || symbology == BARCODE_DPLEIT || symbology == BARCODE_DPIDENT
+            || symbology == BARCODE_ITF14 || symbology == BARCODE_PHARMA_TWO) {
         /* End sbs loop on bar */
         char adj[6] = " -selb";
         memmove(cmd + GS_INITIAL_LEN + sizeof(adj), cmd + GS_INITIAL_LEN, strlen(cmd) + 1 - GS_INITIAL_LEN);
@@ -2809,8 +2898,9 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
         memmove(cmd + GS_INITIAL_LEN + sizeof(adj), cmd + GS_INITIAL_LEN, strlen(cmd) + 1 - GS_INITIAL_LEN);
         memcpy(cmd + GS_INITIAL_LEN, adj, sizeof(adj));
     }
-    if (symbology == BARCODE_POSTNET || symbology == BARCODE_PLANET || symbology == BARCODE_RM4SCC || symbology == BARCODE_JAPANPOST || symbology == BARCODE_KIX
-            || symbology == BARCODE_DAFT || symbology == BARCODE_USPS_IMAIL || symbology == BARCODE_AUSPOST || symbology == BARCODE_PHARMA_TWO) {
+    if (symbology == BARCODE_POSTNET || symbology == BARCODE_PLANET || symbology == BARCODE_RM4SCC
+            || symbology == BARCODE_JAPANPOST || symbology == BARCODE_KIX || symbology == BARCODE_DAFT
+            || symbology == BARCODE_USPS_IMAIL || symbology == BARCODE_AUSPOST || symbology == BARCODE_PHARMA_TWO) {
         /* Emulate rows with BWIPP heights. */
         char adj[5] = " -shs";
         memmove(cmd + GS_INITIAL_LEN + sizeof(adj), cmd + GS_INITIAL_LEN, strlen(cmd) + 1 - GS_INITIAL_LEN);
@@ -2834,21 +2924,25 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
 
     for (r = 0; r < symbol->rows; r++) {
         if (b + symbol->width > be) {
-            fprintf(stderr, "i:%d testUtilBwipp: row %d, width %d, row width iteration overrun (%s)\n", index, r, symbol->width, cmd);
+            fprintf(stderr, "i:%d testUtilBwipp: row %d, width %d, row width iteration overrun (%s)\n",
+                    index, r, symbol->width, cmd);
             testutil_pclose(fp);
             return -1;
         }
-        cnt = fread(b, 1, symbol->width, fp);
+        cnt = (int) fread(b, 1, symbol->width, fp);
         if (cnt != symbol->width) {
-            fprintf(stderr, "i:%d testUtilBwipp: failed to read symbol->width %d bytes, cnt %d (%s)\n", index, symbol->width, cnt, cmd);
+            fprintf(stderr, "i:%d testUtilBwipp: failed to read symbol->width %d bytes, cnt %d (%s)\n",
+                    index, symbol->width, cnt, cmd);
             testutil_pclose(fp);
             return -1;
         }
         b += cnt;
         for (h = bwipp_row_height[r]; h > 1; h--) { /* Ignore row copies if any */
-            cnt = fread(b, 1, symbol->width, fp);
+            cnt = (int) fread(b, 1, symbol->width, fp);
             if (cnt != symbol->width) {
-                fprintf(stderr, "i:%d testUtilBwipp: failed to read/ignore symbol->width %d bytes, cnt %d, h %d, bwipp_row_height[%d] %d, symbol->row_height[%d] %g (%s)\n",
+                fprintf(stderr,
+                        "i:%d testUtilBwipp: failed to read/ignore symbol->width %d bytes, cnt %d, h %d"
+                        ", bwipp_row_height[%d] %d, symbol->row_height[%d] %g (%s)\n",
                         index, symbol->width, cnt, h, r, bwipp_row_height[r], r, symbol->row_height[r], cmd);
                 testutil_pclose(fp);
                 return -1;
@@ -2868,9 +2962,10 @@ int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int
     return 0;
 }
 
+/* Compare bwipp_dump.ps output to test suite module dump */
 int testUtilBwippCmp(const struct zint_symbol *symbol, char *msg, const char *bwipp_buf, const char *expected) {
-    int bwipp_len = strlen(bwipp_buf);
-    int expected_len = strlen(expected);
+    int bwipp_len = (int) strlen(bwipp_buf);
+    int expected_len = (int) strlen(expected);
     int ret_memcmp;
     int i;
 
@@ -2895,9 +2990,11 @@ int testUtilBwippCmp(const struct zint_symbol *symbol, char *msg, const char *bw
     return 0;
 }
 
-int testUtilBwippCmpRow(const struct zint_symbol *symbol, int row, char *msg, const char *bwipp_buf, const char *expected) {
-    int bwipp_len = strlen(bwipp_buf);
-    int expected_len = strlen(expected);
+/* Compare bwipp_dump.ps output to single row module dump (see testUtilModulesPrintRow) */
+int testUtilBwippCmpRow(const struct zint_symbol *symbol, int row, char *msg, const char *bwipp_buf,
+            const char *expected) {
+    int bwipp_len = (int) strlen(bwipp_buf);
+    int expected_len = (int) strlen(expected);
     int ret_memcmp;
     int i, j;
 
diff --git a/backend/tests/testcommon.h b/backend/tests/testcommon.h
index b508d49d..3e017770 100644
--- a/backend/tests/testcommon.h
+++ b/backend/tests/testcommon.h
@@ -70,20 +70,19 @@ extern "C" {
 #endif
 
 #ifndef ARRAY_SIZE
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#define ARRAY_SIZE(x) ((int) (sizeof(x) / sizeof((x)[0])))
 #endif
 
 extern int assertionFailed;
 extern int assertionNum;
+extern const char *assertionFilename;
 
 #if _MSC_VER == 1200 /* VC6 */
 #define testStart(__arg__) (testStartReal("", __arg__))
 #else
 #define testStart(__arg__) (testStartReal(__func__, __arg__))
 #endif
-#define testEndExp(__arg__) (testEnd(!(__arg__)))
 void testStartReal(const char *func, const char *name);
-void testEnd(int result);
 void testFinish(void);
 void testSkip(const char *msg);
 void testReport();
@@ -104,7 +103,8 @@ void assert_equalu64(uint64_t e1, uint64_t e2, const char *fmt, ...);
 void assert_notequal(int e1, int e2, ...);
 #else
 #define assert_exp(__exp__, ...) \
-{assertionNum++; if (!(__exp__)) {assertionFailed++; printf(__VA_ARGS__); testFinish(); return;}}
+    { assertionNum++; if (!(__exp__)) { assertionFailed++; printf("%s:%d ", assertionFilename, __LINE__); \
+      printf(__VA_ARGS__); testFinish(); return; } }
 
 #define assert_zero(__exp__, ...) assert_exp((__exp__) == 0, __VA_ARGS__)
 #define assert_nonzero(__exp__, ...) assert_exp((__exp__) != 0, __VA_ARGS__)
@@ -119,40 +119,47 @@ INTERNAL void vector_free(struct zint_symbol *symbol); /* Free vector structures
 
 int testUtilSetSymbol(struct zint_symbol *symbol, int symbology, int input_mode, int eci,
             int option_1, int option_2, int option_3, int output_options, char *data, int length, int debug);
+
 const char *testUtilBarcodeName(int symbology);
 const char *testUtilErrorName(int error_number);
 const char *testUtilInputModeName(int input_mode);
 const char *testUtilOption3Name(int option_3);
 const char *testUtilOutputOptionsName(int output_options);
+
 int testUtilDAFTConvert(const struct zint_symbol *symbol, char *buffer, int buffer_size);
 int testUtilIsValidUTF8(const unsigned char str[], const int length);
 char *testUtilEscape(char *buffer, int length, char *escaped, int escaped_size);
 char *testUtilReadCSVField(char *buffer, char *field, int field_size);
 void testUtilStrCpyRepeat(char *buffer, char *repeat, int size);
+
 int testUtilSymbolCmp(const struct zint_symbol *a, const struct zint_symbol *b);
 struct zint_vector *testUtilVectorCpy(const struct zint_vector *in);
 int testUtilVectorCmp(const struct zint_vector *a, const struct zint_vector *b);
+
 int testUtilModulesDump(const struct zint_symbol *symbol, char dump[], int dump_size);
 void testUtilModulesPrint(const struct zint_symbol *symbol, const char *prefix, const char *postfix);
 void testUtilModulesPrintRow(const struct zint_symbol *symbol, int row, const char *prefix, const char *postfix);
 int testUtilModulesCmp(const struct zint_symbol *symbol, const char *expected, int *width, int *row);
 int testUtilModulesCmpRow(const struct zint_symbol *symbol, int row, const char *expected, int *width);
-int testUtilModulesDumpHex(const struct zint_symbol *symbol, char dump[], int dump_size);
 char *testUtilUIntArrayDump(unsigned int *array, int size, char *dump, int dump_size);
 char *testUtilUCharArrayDump(unsigned char *array, int size, char *dump, int dump_size);
-int testUtilDataPath(char *buffer, int buffer_size, const char *subdir, const char *filename);
+
 void testUtilBitmapPrint(const struct zint_symbol *symbol, const char *prefix, const char *postfix);
 int testUtilBitmapCmp(const struct zint_symbol *symbol, const char *expected, int *row, int *column);
+
+int testUtilDataPath(char *buffer, int buffer_size, const char *subdir, const char *filename);
 int testUtilExists(const char *filename);
 int testUtilDirExists(const char *dirname);
 int testUtilMkDir(const char *dirname);
 int testUtilRmDir(const char *dirname);
 int testUtilRename(const char *oldpath, const char *newpath);
+
 int testUtilCmpPngs(const char *file1, const char *file2);
 int testUtilCmpTxts(const char *txt1, const char *txt2);
 int testUtilCmpBins(const char *bin1, const char *bin2);
 int testUtilCmpSvgs(const char *svg1, const char *svg2);
 int testUtilCmpEpss(const char *eps1, const char *eps2);
+
 int testUtilHaveIdentify();
 int testUtilVerifyIdentify(const char *filename, int debug);
 int testUtilHaveLibreOffice();
@@ -163,6 +170,7 @@ int testUtilHaveVnu();
 int testUtilVerifyVnu(const char *filename, int debug);
 int testUtilHaveTiffInfo();
 int testUtilVerifyTiffInfo(const char *filename, int debug);
+
 int testUtilCanBwipp(int index, const struct zint_symbol *symbol, int option_1, int option_2, int option_3,
             int debug);
 int testUtilBwipp(int index, const struct zint_symbol *symbol, int option_1, int option_2, int option_3,
diff --git a/backend/upcean.c b/backend/upcean.c
index 800e533e..4e51e625 100644
--- a/backend/upcean.c
+++ b/backend/upcean.c
@@ -30,12 +30,16 @@
  */
 /* vim: set ts=4 sw=4 et : */
 
-#define SODIUM  "0123456789+"
+#define SODIUM          "0123456789+"
+#define ISBN_SANE       "0123456789X"
+#define ISBN_CC_SANE    "0123456789Xx+"
+
 #define EAN2    102
 #define EAN5    105
 
 #include <stdio.h>
 #include "common.h"
+#include "gs1.h"
 
 /* UPC and EAN tables checked against EN 797:1996 */
 
@@ -78,65 +82,44 @@ static const char *EANsetB[10] = {
     "1123", "1222", "2212", "1141", "2311", "1321", "4111", "2131", "3121", "2113"
 };
 
-/* Calculate the correct check digit for a UPC barcode */
-static char upc_check(const char source[], const int length) {
-    int i, count, check_digit;
-
-    count = 0;
-
-    for (i = 0; i < length; i++) {
-        count += (i & 1) ? ctoi(source[i]) : 3 * ctoi(source[i]);
-    }
-
-    check_digit = 10 - (count % 10);
-    if (check_digit == 10) {
-        check_digit = 0;
-    }
-    return itoc(check_digit);
-}
-
 /* UPC A is usually used for 12 digit numbers, but this function takes a source of any length */
-static void upca_draw(const char source[], const int length, unsigned char dest[]) {
+static void upca_draw(const unsigned char source[], const int length, char dest[]) {
     int i, half_way;
 
     half_way = length / 2;
 
     /* start character */
-    ustrcat(dest, "111");
+    strcat(dest, "111");
 
     for (i = 0; i < length; i++) {
         if (i == half_way) {
             /* middle character - separates manufacturer no. from product no. */
             /* also inverts right hand characters */
-            ustrcat(dest, "11111");
+            strcat(dest, "11111");
         }
 
-        lookup(NEON, EANsetA, source[i], (char *) dest);
+        lookup(NEON, EANsetA, source[i], dest);
     }
 
     /* stop character */
-    ustrcat(dest, "111");
+    strcat(dest, "111");
 }
 
 /* Make a UPC-A barcode, allowing for composite if `cc_rows` set */
-static int upca_cc(struct zint_symbol *symbol, const unsigned char source[], int length, unsigned char dest[],
-            int cc_rows) {
-    char gtin[13];
+static int upca_cc(struct zint_symbol *symbol, const unsigned char source[], int length, char dest[], int cc_rows) {
+    unsigned char gtin[13];
     float height;
     int error_number = 0;
 
     ustrcpy(gtin, source);
 
     if (length == 11) {
-        gtin[length++] = upc_check(gtin, 11);
+        gtin[length++] = gs1_check_digit(gtin, 11);
         gtin[length] = '\0';
     } else {
-        if (source[length - 1] != upc_check(gtin, 11)) {
-            if (symbol->debug & ZINT_DEBUG_PRINT) {
-                printf("UPC-A: Invalid check digit %s, gtin: %s, Check digit: %c\n", source, gtin,
-                    upc_check(gtin, 11));
-            }
-            strcpy(symbol->errtxt, "270: Invalid check digit");
+        if (source[length - 1] != gs1_check_digit(gtin, 11)) {
+            sprintf(symbol->errtxt, "270: Invalid check digit '%c', expecting '%c'",
+                    source[length - 1], gs1_check_digit(gtin, 11));
             return ZINT_ERROR_INVALID_CHECK;
         }
     }
@@ -170,15 +153,15 @@ static int upca_cc(struct zint_symbol *symbol, const unsigned char source[], int
 }
 
 /* UPC-A */
-static int upca(struct zint_symbol *symbol, const unsigned char source[], int length, unsigned char dest[]) {
+static int upca(struct zint_symbol *symbol, const unsigned char source[], int length, char dest[]) {
     return upca_cc(symbol, source, length, dest, 0 /*cc_rows*/);
 }
 
 /* UPC-E, allowing for composite if `cc_rows` set */
-static int upce_cc(struct zint_symbol *symbol, unsigned char source[], int length, unsigned char dest[],
-            int cc_rows) {
+static int upce_cc(struct zint_symbol *symbol, unsigned char source[], int length, char dest[], int cc_rows) {
     int i, num_system;
-    char emode, equivalent[12], check_digit, parity[8];
+    char emode, check_digit, parity[8];
+    unsigned char equivalent[12];
     char hrt[9];
     float height;
     int error_number = 0;
@@ -234,7 +217,7 @@ static int upce_cc(struct zint_symbol *symbol, unsigned char source[], int lengt
             equivalent[10] = source[4];
             if (((source[2] == '0') || (source[2] == '1')) || (source[2] == '2')) {
                 /* Note 1 - "X3 shall not be equal to 0, 1 or 2" */
-                strcpy(symbol->errtxt, "271: Invalid UPC-E data");
+                strcpy(symbol->errtxt, "271: Invalid UPC-E data"); // TODO: Better error message
                 return ZINT_ERROR_INVALID_DATA;
             }
             break;
@@ -244,7 +227,7 @@ static int upce_cc(struct zint_symbol *symbol, unsigned char source[], int lengt
             equivalent[10] = source[4];
             if (source[3] == '0') {
                 /* Note 2 - "X4 shall not be equal to 0" */
-                strcpy(symbol->errtxt, "272: Invalid UPC-E data");
+                strcpy(symbol->errtxt, "272: Invalid UPC-E data"); // TODO: Better error message
                 return ZINT_ERROR_INVALID_DATA;
             }
             break;
@@ -259,7 +242,7 @@ static int upce_cc(struct zint_symbol *symbol, unsigned char source[], int lengt
             equivalent[10] = emode;
             if (source[4] == '0') {
                 /* Note 3 - "X5 shall not be equal to 0" */
-                strcpy(symbol->errtxt, "273: Invalid UPC-E data");
+                strcpy(symbol->errtxt, "273: Invalid UPC-E data"); // TODO: Better error message
                 return ZINT_ERROR_INVALID_DATA;
             }
             break;
@@ -267,7 +250,7 @@ static int upce_cc(struct zint_symbol *symbol, unsigned char source[], int lengt
 
     /* Get the check digit from the expanded UPCA code */
 
-    check_digit = upc_check(equivalent, 11);
+    check_digit = gs1_check_digit(equivalent, 11);
 
     /* Use the number system and check digit information to choose a parity scheme */
     if (num_system == 1) {
@@ -279,30 +262,26 @@ static int upce_cc(struct zint_symbol *symbol, unsigned char source[], int lengt
     /* Take all this information and make the barcode pattern */
 
     /* start character */
-    ustrcat(dest, "111");
+    strcat(dest, "111");
 
     for (i = 0; i < length; i++) {
         switch (parity[i]) {
-            case 'A': lookup(NEON, EANsetA, source[i], (char *) dest);
+            case 'A': lookup(NEON, EANsetA, source[i], dest);
                 break;
-            case 'B': lookup(NEON, EANsetB, source[i], (char *) dest);
+            case 'B': lookup(NEON, EANsetB, source[i], dest);
                 break;
         }
     }
 
     /* stop character */
-    ustrcat(dest, "111111");
+    strcat(dest, "111111");
 
     if (symbol->symbology != BARCODE_UPCE_CHK) {
         hrt[7] = check_digit;
         hrt[8] = '\0';
     } else {
         if (hrt[7] != check_digit) {
-            if (symbol->debug & ZINT_DEBUG_PRINT) {
-                printf("UPC-E: Invalid check digit %s, equivalent: %s, hrt: %s, Check digit: %c\n", source,
-                    equivalent, hrt, check_digit);
-            }
-            strcpy(symbol->errtxt, "274: Invalid check digit");
+            sprintf(symbol->errtxt, "274: Invalid check digit '%c', expecting '%c'", hrt[7], check_digit);
             return ZINT_ERROR_INVALID_CHECK;
         }
     }
@@ -334,24 +313,24 @@ static int upce_cc(struct zint_symbol *symbol, unsigned char source[], int lengt
 }
 
 /* UPC-E is a zero-compressed version of UPC-A */
-static int upce(struct zint_symbol *symbol, unsigned char source[], int length, unsigned char dest[]) {
+static int upce(struct zint_symbol *symbol, unsigned char source[], int length, char dest[]) {
     return upce_cc(symbol, source, length, dest, 0 /*cc_rows*/);
 }
 
 /* EAN-2 and EAN-5 add-on codes */
-static void add_on(const unsigned char source[], const int length, unsigned char dest[], const int addon_gap) {
+static void ean_add_on(const unsigned char source[], const int length, char dest[], const int addon_gap) {
     char parity[6];
     int i, code_type;
 
     /* If an add-on then append with space */
     if (addon_gap != 0) {
-        i = (int) ustrlen(dest);
+        i = (int) strlen(dest);
         dest[i] = itoc(addon_gap);
         dest[i + 1] = '\0';
     }
 
     /* Start character */
-    ustrcat(dest, "112");
+    strcat(dest, "112");
 
     /* Determine EAN2 or EAN5 add-on */
     if (length == 2) {
@@ -385,43 +364,26 @@ static void add_on(const unsigned char source[], const int length, unsigned char
 
     for (i = 0; i < length; i++) {
         switch (parity[i]) {
-            case 'A': lookup(NEON, EANsetA, source[i], (char *) dest);
+            case 'A': lookup(NEON, EANsetA, source[i], dest);
                 break;
-            case 'B': lookup(NEON, EANsetB, source[i], (char *) dest);
+            case 'B': lookup(NEON, EANsetB, source[i], dest);
                 break;
         }
 
         /* Glyph separator */
         if (i != (length - 1)) {
-            ustrcat(dest, "11");
+            strcat(dest, "11");
         }
     }
 }
 
 /* ************************ EAN-13 ****************** */
 
-/* Calculate the correct check digit for a EAN-13 barcode (including ISBN(13)) */
-static char ean_check(const char source[], const int length) {
-    int i;
-    int count, check_digit;
-
-    count = 0;
-
-    for (i = 0; i < length; i++) {
-        count += (i & 1) ? 3 * ctoi(source[i]) : ctoi(source[i]);
-    }
-    check_digit = 10 - (count % 10);
-    if (check_digit == 10) {
-        check_digit = 0;
-    }
-    return itoc(check_digit);
-}
-
-static int ean13_cc(struct zint_symbol *symbol, const unsigned char source[], int length, unsigned char dest[],
+static int ean13_cc(struct zint_symbol *symbol, const unsigned char source[], int length, char dest[],
             int cc_rows) {
     int i, half_way;
     char parity[6];
-    char gtin[14];
+    unsigned char gtin[14];
     float height;
     int error_number = 0;
 
@@ -431,15 +393,12 @@ static int ean13_cc(struct zint_symbol *symbol, const unsigned char source[], in
     /* Add the appropriate check digit */
 
     if (length == 12) {
-        gtin[length++] = ean_check(gtin, 12);
+        gtin[length++] = gs1_check_digit(gtin, 12);
         gtin[length] = '\0';
     } else {
-        if (source[length - 1] != ean_check(gtin, 12)) {
-            if (symbol->debug & ZINT_DEBUG_PRINT) {
-                printf("EAN-13 Invalid check digit: %s, gtin: %s, Check digit: %c\n", source, gtin,
-                    ean_check(gtin, 12));
-            }
-            strcpy(symbol->errtxt, "275: Invalid check digit");
+        if (source[length - 1] != gs1_check_digit(gtin, 12)) {
+            sprintf(symbol->errtxt, "275: Invalid check digit '%c', expecting '%c'",
+                    source[length - 1], gs1_check_digit(gtin, 12));
             return ZINT_ERROR_INVALID_CHECK;
         }
     }
@@ -454,23 +413,23 @@ static int ean13_cc(struct zint_symbol *symbol, const unsigned char source[], in
     half_way = 7;
 
     /* start character */
-    ustrcat(dest, "111");
+    strcat(dest, "111");
     for (i = 1; i < length; i++) {
         if (i == half_way) {
             /* middle character - separates manufacturer no. from product no. */
             /* also inverses right hand characters */
-            ustrcat(dest, "11111");
+            strcat(dest, "11111");
         }
 
         if (((i > 1) && (i < 7)) && (parity[i - 2] == 'B')) {
-            lookup(NEON, EANsetB, gtin[i], (char *) dest);
+            lookup(NEON, EANsetB, gtin[i], dest);
         } else {
-            lookup(NEON, EANsetA, gtin[i], (char *) dest);
+            lookup(NEON, EANsetA, gtin[i], dest);
         }
     }
 
     /* stop character */
-    ustrcat(dest, "111");
+    strcat(dest, "111");
     ustrcpy(symbol->text, gtin);
 
 #ifdef COMPLIANT_HEIGHTS
@@ -494,29 +453,25 @@ static int ean13_cc(struct zint_symbol *symbol, const unsigned char source[], in
     return error_number;
 }
 
-static int ean13(struct zint_symbol *symbol, const unsigned char source[], int length, unsigned char dest[]) {
+static int ean13(struct zint_symbol *symbol, const unsigned char source[], int length, char dest[]) {
     return ean13_cc(symbol, source, length, dest, 0 /*cc_rows*/);
 }
 
-static int ean8_cc(struct zint_symbol *symbol, const unsigned char source[], int length, unsigned char dest[],
-            int cc_rows) {
+static int ean8_cc(struct zint_symbol *symbol, const unsigned char source[], int length, char dest[], int cc_rows) {
     /* EAN-8 is basically the same as UPC-A but with fewer digits */
-    char gtin[10];
+    unsigned char gtin[10];
     float height;
     int error_number = 0;
 
     ustrcpy(gtin, source);
 
     if (length == 7) {
-        gtin[length++] = upc_check(gtin, 7);
+        gtin[length++] = gs1_check_digit(gtin, 7);
         gtin[length] = '\0';
     } else {
-        if (source[length - 1] != upc_check(gtin, 7)) {
-            if (symbol->debug & ZINT_DEBUG_PRINT) {
-                printf("EAN-8: Invalid check digit %s, gtin: %s, Check digit: %c\n", source, gtin,
-                    upc_check(gtin, 7));
-            }
-            strcpy(symbol->errtxt, "276: Invalid check digit");
+        if (source[length - 1] != gs1_check_digit(gtin, 7)) {
+            sprintf(symbol->errtxt, "276: Invalid check digit '%c', expecting '%c'",
+                    source[length - 1], gs1_check_digit(gtin, 7));
             return ZINT_ERROR_INVALID_CHECK;
         }
     }
@@ -550,7 +505,7 @@ static int ean8_cc(struct zint_symbol *symbol, const unsigned char source[], int
 }
 
 /* Make an EAN-8 barcode when we haven't been given the check digit */
-static int ean8(struct zint_symbol *symbol, const unsigned char source[], int length, unsigned char dest[]) {
+static int ean8(struct zint_symbol *symbol, const unsigned char source[], int length, char dest[]) {
     return ean8_cc(symbol, source, length, dest, 0 /*cc_rows*/);
 }
 
@@ -576,36 +531,34 @@ static char isbn_check(const unsigned char source[], const int length) {
 }
 
 /* Make an EAN-13 barcode from an SBN or ISBN */
-static int isbn(struct zint_symbol *symbol, unsigned char source[], const int src_len, unsigned char dest[]) {
+static int isbn(struct zint_symbol *symbol, unsigned char source[], const int src_len, char dest[]) {
     int i, error_number;
     char check_digit;
 
     to_upper(source);
-    error_number = is_sane("0123456789X", source, src_len);
+    error_number = is_sane(ISBN_SANE, source, src_len);
     if (error_number == ZINT_ERROR_INVALID_DATA) {
-        strcpy(symbol->errtxt, "277: Invalid characters in input");
+        sprintf(symbol->errtxt, "277: Invalid characters in data (\"%s\" only)", ISBN_SANE);
         return error_number;
     }
 
     /* Input must be 9, 10 or 13 characters */
     if (src_len != 9 && src_len != 10 && src_len != 13) {
-        strcpy(symbol->errtxt, "278: Input wrong length");
+        strcpy(symbol->errtxt, "278: Input wrong length (9, 10, or 13 characters only)");
         return ZINT_ERROR_TOO_LONG;
     }
 
     if (src_len == 13) /* Using 13 character ISBN */ {
         if (!(((source[0] == '9') && (source[1] == '7')) &&
                 ((source[2] == '8') || (source[2] == '9')))) {
-            strcpy(symbol->errtxt, "279: Invalid ISBN");
+            strcpy(symbol->errtxt, "279: Invalid ISBN (must begin with \"978\" or \"979\")");
             return ZINT_ERROR_INVALID_DATA;
         }
 
-        check_digit = ean_check((const char *) source, 12);
+        check_digit = gs1_check_digit(source, 12);
         if (source[src_len - 1] != check_digit) {
-            if (symbol->debug & ZINT_DEBUG_PRINT) {
-                printf("ISBN: Invalid check digit %s, Check digit: %c\n", source, check_digit);
-            }
-            strcpy(symbol->errtxt, "280: Incorrect ISBN check");
+            sprintf(symbol->errtxt, "280: Incorrect ISBN check '%c', expecting '%c'",
+                    source[src_len - 1], check_digit);
             return ZINT_ERROR_INVALID_CHECK;
         }
         source[12] = '\0';
@@ -622,10 +575,8 @@ static int isbn(struct zint_symbol *symbol, unsigned char source[], const int sr
     if (src_len == 9 || src_len == 10) /* Using 10 digit ISBN or 9 digit SBN padded with leading zero */ {
         check_digit = isbn_check(source, 9);
         if (check_digit != source[9]) {
-            if (symbol->debug & ZINT_DEBUG_PRINT) {
-                printf("ISBN(10)/SBN: Invalid check digit %s, Check digit: %c\n", source, check_digit);
-            }
-            strcpy(symbol->errtxt, src_len == 9 ? "281: Incorrect SBN check" : "281: Incorrect ISBN check");
+            sprintf(symbol->errtxt, "281: Incorrect %s check '%c', expecting '%c'", src_len == 9 ? "SBN" : "ISBN",
+                    source[9], check_digit);
             return ZINT_ERROR_INVALID_CHECK;
         }
         for (i = 11; i > 2; i--) {
@@ -782,8 +733,9 @@ INTERNAL int ean_leading_zeroes(struct zint_symbol *symbol, const unsigned char
 }
 
 INTERNAL int eanx_cc(struct zint_symbol *symbol, unsigned char source[], int src_len, int cc_rows) {
-    unsigned char first_part[14] = {0}, second_part[6] = {0}, dest[1000] = {0};
+    unsigned char first_part[14] = {0}, second_part[6] = {0};
     unsigned char local_source[20] = {0}; /* Allow 13 + "+" + 5 + 1 */
+    char dest[1000] = {0};
     int latch, reader, writer;
     int with_addon;
     int error_number, i, plus_count;
@@ -795,20 +747,20 @@ INTERNAL int eanx_cc(struct zint_symbol *symbol, unsigned char source[], int src
     writer = 0;
 
     if (src_len > 19) {
-        strcpy(symbol->errtxt, "283: Input too long");
+        strcpy(symbol->errtxt, "283: Input too long"); // TODO: Better error message
         return ZINT_ERROR_TOO_LONG;
     }
     if (symbol->symbology != BARCODE_ISBNX) {
         /* ISBN has its own checking routine */
-        error_number = is_sane("0123456789+", source, src_len);
+        error_number = is_sane(SODIUM, source, src_len);
         if (error_number == ZINT_ERROR_INVALID_DATA) {
-            strcpy(symbol->errtxt, "284: Invalid characters in data");
+            sprintf(symbol->errtxt, "284: Invalid characters in data (\"%s\" only)", SODIUM);
             return error_number;
         }
     } else {
-        error_number = is_sane("0123456789Xx+", source, src_len);
+        error_number = is_sane(ISBN_CC_SANE, source, src_len);
         if (error_number == ZINT_ERROR_INVALID_DATA) {
-            strcpy(symbol->errtxt, "285: Invalid characters in input");
+            sprintf(symbol->errtxt, "285: Invalid characters in data (\"%s\" only)", ISBN_CC_SANE);
             return error_number;
         }
     }
@@ -818,16 +770,16 @@ INTERNAL int eanx_cc(struct zint_symbol *symbol, unsigned char source[], int src
     for (i = 0; i < src_len; i++) {
         if (source[i] == '+') {
             plus_count++;
+            if (plus_count > 1) {
+                strcpy(symbol->errtxt, "293: Invalid add-on data (one \"+\" only)");
+                return ZINT_ERROR_INVALID_DATA;
+            }
         }
     }
-    if (plus_count > 1) {
-        strcpy(symbol->errtxt, "293: Invalid add-on data");
-        return ZINT_ERROR_INVALID_DATA;
-    }
 
     /* Add leading zeroes, checking max lengths of parts */
     if (!ean_leading_zeroes(symbol, source, local_source, &with_addon)) {
-        strcpy(symbol->errtxt, "294: Input too long");
+        strcpy(symbol->errtxt, "294: Input too long"); // TODO: Better error message
         return ZINT_ERROR_TOO_LONG;
     }
 
@@ -869,7 +821,7 @@ INTERNAL int eanx_cc(struct zint_symbol *symbol, unsigned char source[], int src
         case BARCODE_EANX:
         case BARCODE_EANX_CHK:
             switch (first_part_len) {
-                case 2: add_on(first_part, first_part_len, dest, 0);
+                case 2: ean_add_on(first_part, first_part_len, dest, 0);
                     ustrcpy(symbol->text, first_part);
 #ifdef COMPLIANT_HEIGHTS
                     /* 21.9mm from GS1 General Specifications 5.2.6.6, Figure 5.2.6.6-5 */
@@ -880,7 +832,7 @@ INTERNAL int eanx_cc(struct zint_symbol *symbol, unsigned char source[], int src
                     (void) set_height(symbol, 0.0f, height, 0.0f, 1 /*no_errtxt*/);
 #endif
                     break;
-                case 5: add_on(first_part, first_part_len, dest, 0);
+                case 5: ean_add_on(first_part, first_part_len, dest, 0);
                     ustrcpy(symbol->text, first_part);
 #ifdef COMPLIANT_HEIGHTS
                     /* 21.9mm from GS1 General Specifications 5.2.6.6, Figure 5.2.6.6-6 */
@@ -897,7 +849,7 @@ INTERNAL int eanx_cc(struct zint_symbol *symbol, unsigned char source[], int src
                 case 12:
                 case 13: error_number = ean13(symbol, first_part, first_part_len, dest);
                     break;
-                default: strcpy(symbol->errtxt, "286: Input wrong length");
+                default: strcpy(symbol->errtxt, "286: Input wrong length"); // TODO: Better error message
                     return ZINT_ERROR_TOO_LONG;
             }
             break;
@@ -928,7 +880,7 @@ INTERNAL int eanx_cc(struct zint_symbol *symbol, unsigned char source[], int src
                     symbol->rows += 3;
                     error_number = ean13_cc(symbol, first_part, first_part_len, dest, cc_rows);
                     break;
-                default: strcpy(symbol->errtxt, "287: Input wrong length");
+                default: strcpy(symbol->errtxt, "287: Input wrong length"); // TODO: Better error message
                     return ZINT_ERROR_TOO_LONG;
             }
             break;
@@ -937,7 +889,7 @@ INTERNAL int eanx_cc(struct zint_symbol *symbol, unsigned char source[], int src
             if ((first_part_len == 11) || (first_part_len == 12)) {
                 error_number = upca(symbol, first_part, first_part_len, dest);
             } else {
-                strcpy(symbol->errtxt, "288: Input wrong length");
+                strcpy(symbol->errtxt, "288: Input wrong length"); // TODO: Better error message
                 return ZINT_ERROR_TOO_LONG;
             }
             break;
@@ -955,7 +907,7 @@ INTERNAL int eanx_cc(struct zint_symbol *symbol, unsigned char source[], int src
                 symbol->rows += 3;
                 error_number = upca_cc(symbol, first_part, first_part_len, dest, cc_rows);
             } else {
-                strcpy(symbol->errtxt, "289: Input wrong length");
+                strcpy(symbol->errtxt, "289: Input wrong length"); // TODO: Better error message
                 return ZINT_ERROR_TOO_LONG;
             }
             break;
@@ -964,7 +916,7 @@ INTERNAL int eanx_cc(struct zint_symbol *symbol, unsigned char source[], int src
             if ((first_part_len >= 6) && (first_part_len <= (symbol->symbology == BARCODE_UPCE ? 7 : 8))) {
                 error_number = upce(symbol, first_part, first_part_len, dest);
             } else {
-                strcpy(symbol->errtxt, "290: Input wrong length");
+                strcpy(symbol->errtxt, "290: Input wrong length"); // TODO: Better error message
                 return ZINT_ERROR_TOO_LONG;
             }
             break;
@@ -982,7 +934,7 @@ INTERNAL int eanx_cc(struct zint_symbol *symbol, unsigned char source[], int src
                 symbol->rows += 3;
                 error_number = upce_cc(symbol, first_part, first_part_len, dest, cc_rows);
             } else {
-                strcpy(symbol->errtxt, "291: Input wrong length");
+                strcpy(symbol->errtxt, "291: Input wrong length"); // TODO: Better error message
                 return ZINT_ERROR_TOO_LONG;
             }
             break;
@@ -1000,17 +952,17 @@ INTERNAL int eanx_cc(struct zint_symbol *symbol, unsigned char source[], int src
     switch (second_part_len) {
         case 0: break;
         case 2:
-            add_on(second_part, second_part_len, dest, addon_gap);
+            ean_add_on(second_part, second_part_len, dest, addon_gap);
             ustrcat(symbol->text, "+");
             ustrcat(symbol->text, second_part);
             break;
         case 5:
-            add_on(second_part, second_part_len, dest, addon_gap);
+            ean_add_on(second_part, second_part_len, dest, addon_gap);
             ustrcat(symbol->text, "+");
             ustrcat(symbol->text, second_part);
             break;
         default:
-            strcpy(symbol->errtxt, "292: Add-on input wrong length");
+            strcpy(symbol->errtxt, "292: Add-on input wrong length"); // TODO: Better error message
             return ZINT_ERROR_TOO_LONG;
     }
 
diff --git a/docs/manual.txt b/docs/manual.txt
index 2c302e2e..b42d77cb 100644
--- a/docs/manual.txt
+++ b/docs/manual.txt
@@ -1114,7 +1114,7 @@ ZINT_ERROR_INVALID_DATA      |  The data to be encoded includes characters which
                              |     are not permitted by the selected symbology
                              |     (e.g. alphabetic characters in an EAN
                              |     symbol). No symbol has been generated.
-ZINT_ERROR_INVALID_CHECK     |  An ISBN with an incorrect check digit has been
+ZINT_ERROR_INVALID_CHECK     |  Data with an incorrect check digit has been
                              |     entered. No symbol has been generated.
 ZINT_ERROR_INVALID_OPTION    |  One of the values in zint_struct was set
                              |     incorrectly and Zint was unable to guess what
@@ -1131,7 +1131,7 @@ ZINT_ERROR_MEMORY            |  Zint ran out of memory. This should only be a
                              |     problem with legacy systems.
 ZINT_ERROR_FILE_WRITE        |  Zint failed to write all contents to the
                              |     requested output file. This should only occur
-                             |     if the output disk becomes full.
+                             |     if the output device becomes full.
 --------------------------------------------------------------------------------
 
 To catch errors use an integer variable as shown in the code below:
diff --git a/frontend/main.c b/frontend/main.c
index 95fb00a0..d28dc8d8 100644
--- a/frontend/main.c
+++ b/frontend/main.c
@@ -41,7 +41,7 @@
 typedef int static_assert_int_at_least_32bits[CHAR_BIT != 8 || sizeof(int) < 4 ? -1 : 1];
 
 #ifndef ARRAY_SIZE
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#define ARRAY_SIZE(x) ((int) (sizeof(x) / sizeof((x)[0])))
 #endif
 
 /* Print list of supported symbologies */
@@ -140,7 +140,7 @@ static void usage(void) {
             "  --filetype=TYPE       Set output file type BMP/EMF/EPS/GIF/PCX/PNG/SVG/TIF/TXT\n"
             "  --fullmultibyte       Use multibyte for binary/Latin (QR/Han Xin/Grid Matrix)\n"
             "  --gs1                 Treat input as GS1 compatible data\n"
-            "  --gs1parens           GS1 AIs in parentheses instead of square brackets\n"
+            "  --gs1parens           Process parentheses \"()\" as GS1 AI delimiters, not \"[]\"\n"
             "  --gssep               Use separator GS for GS1 (Data Matrix)\n"
             "  -h, --help            Display help message\n"
             "  --height=NUMBER       Set height of symbol in multiples of X-dimension\n"
@@ -157,7 +157,7 @@ static void usage(void) {
             "  --rotate=NUMBER       Rotate symbol by NUMBER degrees\n"
             "  --rows=NUMBER         Set number of rows (Codablock-F)\n"
             "  --scale=NUMBER        Adjust size of X-dimension\n"
-            "  --scmvv=NUMBER        Prefix SCM with [)>\\R01\\Gvv (vv is NUMBER) (MaxiCode)\n"
+            "  --scmvv=NUMBER        Prefix SCM with \"[)>\\R01\\Gvv\" (vv is NUMBER) (MaxiCode)\n"
             "  --secure=NUMBER       Set error correction level (ECC)\n"
             "  --separator=NUMBER    Set height of row separator bars (stacked symbologies)\n"
             "  --small               Use small text\n"
@@ -423,7 +423,7 @@ static int supported_filetype(const char *filetype, const int no_png, int *png_r
         return 0;
     }
 
-    for (i = 0; i < (int) ARRAY_SIZE(filetypes); i++) {
+    for (i = 0; i < ARRAY_SIZE(filetypes); i++) {
         if (strcmp(lc_filetype, filetypes[i]) == 0) {
             return 1;
         }
@@ -486,7 +486,7 @@ static int is_raster(const char *filetype, const int no_png) {
         return 0;
     }
 
-    for (i = 0; i < (int) ARRAY_SIZE(raster_filetypes); i++) {
+    for (i = 0; i < ARRAY_SIZE(raster_filetypes); i++) {
         if (strcmp(lc_filetype, raster_filetypes[i]) == 0) {
             return 1;
         }
diff --git a/frontend/tests/test_args.c b/frontend/tests/test_args.c
index 71c009bc..9605e983 100644
--- a/frontend/tests/test_args.c
+++ b/frontend/tests/test_args.c
@@ -107,7 +107,7 @@ static char *exec(const char *cmd, char *buf, int buf_size, int debug, int index
         fprintf(stderr, "exec: failed to run '%s'\n", cmd);
         return NULL;
     }
-    cnt = fread(buf, 1, buf_size, fp);
+    cnt = (int) fread(buf, 1, buf_size, fp);
     if (fgetc(fp) != EOF) {
         fprintf(stderr, "exec: failed to read full stream (%s)\n", cmd);
         testutil_pclose(fp);
@@ -161,7 +161,7 @@ static int arg_input(char *cmd, const char *filename, const char *input) {
                 fprintf(stderr, "arg_input: failed to open '%s' for writing\n", filename);
                 return 0;
             }
-            cnt = fwrite(input, 1, strlen(input), fp);
+            cnt = (int) fwrite(input, 1, strlen(input), fp);
             if (cnt != (int) strlen(input)) {
                 fprintf(stderr, "arg_input: failed to write %d bytes, cnt %d written (%s)\n", (int) strlen(input), cnt, filename);
                 fclose(fp);