diff --git a/backend/code128.c b/backend/code128.c
index 425f1004..e9279cb6 100644
--- a/backend/code128.c
+++ b/backend/code128.c
@@ -30,6 +30,7 @@
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
  */
+/* vim: set ts=4 sw=4 et : */
 
 #include <stdio.h>
 #include <string.h>
@@ -689,7 +690,11 @@ int ean_128(struct zint_symbol *symbol, unsigned char source[], const size_t len
     float glyph_count;
     char dest[1000];
     int separator_row, linkage_flag, c_count;
-
+#ifndef _MSC_VER
+    char reduced[length + 1];
+#else
+    char* reduced = (char*) _alloca(length + 1);
+#endif
     error_number = 0;
     strcpy(dest, "");
     linkage_flag = 0;
@@ -707,13 +712,6 @@ int ean_128(struct zint_symbol *symbol, unsigned char source[], const size_t len
         strcpy(symbol->errtxt, "342: Input too long");
         return ZINT_ERROR_TOO_LONG;
     }
-    for (i = 0; i < length; i++) {
-        if (source[i] == '\0') {
-            /* Null characters not allowed! */
-            strcpy(symbol->errtxt, "343: NULL character in input data");
-            return ZINT_ERROR_INVALID_DATA;
-        }
-    }
 
     /* if part of a composite symbol make room for the separator pattern */
     if (symbol->symbology == BARCODE_EAN128_CC) {
@@ -722,12 +720,17 @@ int ean_128(struct zint_symbol *symbol, unsigned char source[], const size_t len
         symbol->rows += 1;
     }
 
+    error_number = gs1_verify(symbol, source, length, reduced);
+    if (error_number != 0) {
+        return error_number;
+    }
+
     /* Decide on mode using same system as PDF417 and rules of ISO 15417 Annex E */
     indexliste = 0;
     indexchaine = 0;
 
-    mode = parunmodd(source[indexchaine]);
-    if (source[indexchaine] == '[') {
+    mode = parunmodd(reduced[indexchaine]);
+    if (reduced[indexchaine] == '[') {
         mode = ABORC;
     }
 
@@ -737,16 +740,16 @@ int ean_128(struct zint_symbol *symbol, unsigned char source[], const size_t len
 
     do {
         list[1][indexliste] = mode;
-        while ((list[1][indexliste] == mode) && (indexchaine < (int) ustrlen(source))) {
+        while ((list[1][indexliste] == mode) && (indexchaine < (int) strlen(reduced))) {
             list[0][indexliste]++;
             indexchaine++;
-            mode = parunmodd(source[indexchaine]);
-            if (source[indexchaine] == '[') {
+            mode = parunmodd(reduced[indexchaine]);
+            if (reduced[indexchaine] == '[') {
                 mode = ABORC;
             }
         }
         indexliste++;
-    } while (indexchaine < (int) ustrlen(source));
+    } while (indexchaine < (int) strlen(reduced));
 
     dxsmooth(&indexliste);
 
@@ -774,7 +777,7 @@ int ean_128(struct zint_symbol *symbol, unsigned char source[], const size_t len
     c_count = 0;
     for (i = 0; i < read; i++) {
         if (set[i] == 'C') {
-            if (source[i] == '[') {
+            if (reduced[i] == '[') {
                 if (c_count & 1) {
                     if ((i - c_count) != 0) {
                         set[i - c_count] = 'B';
@@ -814,7 +817,7 @@ int ean_128(struct zint_symbol *symbol, unsigned char source[], const size_t len
     being too long */
     last_set = ' ';
     glyph_count = 0.0;
-    for (i = 0; i < (int) ustrlen(source); i++) {
+    for (i = 0; i < (int) strlen(reduced); i++) {
         if ((set[i] == 'a') || (set[i] == 'b')) {
             glyph_count = glyph_count + 1.0;
         }
@@ -825,7 +828,7 @@ int ean_128(struct zint_symbol *symbol, unsigned char source[], const size_t len
             }
         }
 
-        if ((set[i] == 'C') && (source[i] != '[')) {
+        if ((set[i] == 'C') && (reduced[i] != '[')) {
             glyph_count = glyph_count + 0.5;
         } else {
             glyph_count = glyph_count + 1.0;
@@ -885,20 +888,20 @@ int ean_128(struct zint_symbol *symbol, unsigned char source[], const size_t len
             bar_characters++;
         }
 
-        if (source[read] != '[') {
+        if (reduced[read] != '[') {
             switch (set[read]) { /* Encode data characters */
                 case 'A':
                 case 'a':
-                    c128_set_a(source[read], dest, values, &bar_characters);
+                    c128_set_a(reduced[read], dest, values, &bar_characters);
                     read++;
                     break;
                 case 'B':
                 case 'b':
-                    c128_set_b(source[read], dest, values, &bar_characters);
+                    c128_set_b(reduced[read], dest, values, &bar_characters);
                     read++;
                     break;
                 case 'C':
-                    c128_set_c(source[read], source[read + 1], dest, values, &bar_characters);
+                    c128_set_c(reduced[read], reduced[read + 1], dest, values, &bar_characters);
                     read += 2;
                     break;
             }
@@ -908,7 +911,7 @@ int ean_128(struct zint_symbol *symbol, unsigned char source[], const size_t len
             bar_characters++;
             read++;
         }
-    } while (read < (int) ustrlen(source));
+    } while (read < (int) strlen(reduced));
 
     /* "...note that the linkage flag is an extra code set character between
     the last data character and the Symbol Check Character" (GS1 Specification) */
@@ -919,7 +922,7 @@ int ean_128(struct zint_symbol *symbol, unsigned char source[], const size_t len
         case 1:
         case 2:
             /* CC-A or CC-B 2D component */
-            switch (set[ustrlen(source) - 1]) {
+            switch (set[strlen(reduced) - 1]) {
                 case 'A': linkage_flag = 100;
                     break;
                 case 'B': linkage_flag = 99;
@@ -930,7 +933,7 @@ int ean_128(struct zint_symbol *symbol, unsigned char source[], const size_t len
             break;
         case 3:
             /* CC-C 2D component */
-            switch (set[ustrlen(source) - 1]) {
+            switch (set[strlen(reduced) - 1]) {
                 case 'A': linkage_flag = 99;
                     break;
                 case 'B': linkage_flag = 101;
diff --git a/backend/common.c b/backend/common.c
index 020a07cc..9ba3b326 100644
--- a/backend/common.c
+++ b/backend/common.c
@@ -29,6 +29,7 @@
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
  */
+/* vim: set ts=4 sw=4 et : */
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -232,6 +233,11 @@ int is_extendable(const int symbology) {
     return 0;
 }
 
+/* Indicates which symbols can have composite 2D component data */
+int is_composite(int symbology) {
+    return symbology >= BARCODE_EANX_CC && symbology <= BARCODE_RSS_EXPSTACK_CC;
+}
+
 int istwodigits(const unsigned char source[], const size_t position) {
     if ((source[position] >= '0') && (source[position] <= '9')) {
         if ((source[position + 1] >= '0') && (source[position + 1] <= '9')) {
diff --git a/backend/common.h b/backend/common.h
index 2607d6a3..7e1cfab3 100644
--- a/backend/common.h
+++ b/backend/common.h
@@ -29,6 +29,7 @@
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
  */
+/* vim: set ts=4 sw=4 et : */
 
 /* Used in some logic */
 #ifndef __COMMON_H
@@ -70,6 +71,7 @@ extern "C" {
     extern void unset_module(struct zint_symbol *symbol, const int y_coord, const int x_coord);
     extern int is_stackable(const int symbology);
     extern int is_extendable(const int symbology);
+    extern int is_composite(const int symbology);
     extern int utf8toutf16(struct zint_symbol *symbol, const unsigned char source[], int vals[], size_t *length);
     extern void set_minimum_height(struct zint_symbol *symbol, const int min_height);
 #ifdef __cplusplus
diff --git a/backend/composite.c b/backend/composite.c
index 2751195d..8552aa45 100644
--- a/backend/composite.c
+++ b/backend/composite.c
@@ -1883,10 +1883,9 @@ int composite(struct zint_symbol *symbol, unsigned char source[], int length) {
             }
         }
     }
-    if ((linear->width + bottom_shift) > symbol->width) {
+    if ((linear->width + bottom_shift) > symbol->width + top_shift) {
         symbol->width = linear->width + bottom_shift;
-    }
-    if ((symbol->width + top_shift) > symbol->width) {
+    } else if ((symbol->width + top_shift) > linear->width + bottom_shift) {
         symbol->width += top_shift;
     }
     symbol->rows += linear->rows;
diff --git a/backend/gs1.c b/backend/gs1.c
index 74e3ed41..bb6969db 100644
--- a/backend/gs1.c
+++ b/backend/gs1.c
@@ -82,8 +82,12 @@ int gs1_verify(struct zint_symbol *symbol, const unsigned char source[], const s
             strcpy(symbol->errtxt, "250: Extended ASCII characters are not supported by GS1");
             return ZINT_ERROR_INVALID_DATA;
         }
+        if (source[i] == '\0') {
+            strcpy(symbol->errtxt, "262: NUL characters not permitted in GS1 mode");
+            return ZINT_ERROR_INVALID_DATA;
+        }
         if (source[i] < 32) {
-            strcpy(symbol->errtxt, "251: Control characters are not supported by GS1 ");
+            strcpy(symbol->errtxt, "251: Control characters are not supported by GS1");
             return ZINT_ERROR_INVALID_DATA;
         }
     }
@@ -662,26 +666,3 @@ int gs1_verify(struct zint_symbol *symbol, const unsigned char source[], const s
     /* the character '[' in the reduced string refers to the FNC1 character */
     return 0;
 }
-
-int ugs1_verify(struct zint_symbol *symbol, const unsigned char source[], const unsigned int src_len, unsigned char reduced[]) {
-    /* Only to keep the compiler happy */
-#ifndef _MSC_VER
-    char temp[src_len + 5];
-#else
-    char* temp = (char*) _alloca(src_len + 5);
-#endif
-    int error_number;
-
-    error_number = gs1_verify(symbol, source, src_len, temp);
-    if (error_number != 0) {
-        return error_number;
-    }
-
-    if (strlen(temp) < src_len + 5) {
-        ustrcpy(reduced, (unsigned char*) temp);
-        return 0;
-    }
-    strcpy(symbol->errtxt, "261: ugs1_verify overflow");
-    return ZINT_ERROR_INVALID_DATA;
-}
-
diff --git a/backend/gs1.h b/backend/gs1.h
index 0dba0841..228af50d 100644
--- a/backend/gs1.h
+++ b/backend/gs1.h
@@ -29,6 +29,7 @@
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
  */
+/* vim: set ts=4 sw=4 et : */
 #ifndef __GS1_H
 #define __GS1_H
 
@@ -37,10 +38,9 @@ extern "C" {
 #endif /* __cplusplus */
 
     extern int gs1_verify(struct zint_symbol *symbol, const unsigned char source[], const size_t src_len, char reduced[]);
-    extern int ugs1_verify(struct zint_symbol *symbol, const unsigned char source[], const unsigned int src_len, unsigned char reduced[]);
 
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */
 
-#endif /* __GS1_H */
\ No newline at end of file
+#endif /* __GS1_H */
diff --git a/backend/library.c b/backend/library.c
index f61c05c4..48a9c62d 100644
--- a/backend/library.c
+++ b/backend/library.c
@@ -28,6 +28,7 @@
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
  */
+/* vim: set ts=4 sw=4 et : */
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -385,22 +386,14 @@ static void check_row_heights(struct zint_symbol *symbol) {
 static int check_force_gs1(const int symbology) {
     /* Returns 1 if symbology MUST have GS1 data */
     
-    int result = 0;
-    
+    int result = is_composite(symbology);
+
     switch (symbology) {
         case BARCODE_EAN128:
+        case BARCODE_EAN14:
+        case BARCODE_NVE18:
         case BARCODE_RSS_EXP:
         case BARCODE_RSS_EXPSTACK:
-        case BARCODE_EANX_CC:
-        case BARCODE_EAN128_CC:
-        case BARCODE_RSS14_CC:
-        case BARCODE_RSS_LTD_CC:
-        case BARCODE_RSS_EXP_CC:
-        case BARCODE_UPCA_CC:
-        case BARCODE_UPCE_CC:
-        case BARCODE_RSS14STACK_CC:
-        case BARCODE_RSS14_OMNI_CC:
-        case BARCODE_RSS_EXPSTACK_CC:
             result = 1;
             break;
     }
@@ -1138,13 +1131,6 @@ int ZBarcode_Encode(struct zint_symbol *symbol, const unsigned char *source, int
         error_number = ZINT_WARN_INVALID_OPTION;
     }
 
-    if (error_number > 4) {
-        error_tag(symbol->errtxt, error_number);
-        return error_number;
-    } else {
-        error_buffer = error_number;
-    }
-
     if ((!(supports_eci(symbol->symbology))) && (symbol->eci != 0)) {
         strcpy(symbol->errtxt, "217: Symbology does not support ECI switching");
         error_number = ZINT_ERROR_INVALID_OPTION;
@@ -1155,31 +1141,22 @@ int ZBarcode_Encode(struct zint_symbol *symbol, const unsigned char *source, int
         error_number = ZINT_ERROR_INVALID_OPTION;
     }
 
-    /* Start acting on input mode */
-    if ((input_mode == GS1_MODE) || (check_force_gs1(symbol->symbology))) {
-        for (i = 0; i < in_length; i++) {
-            if (source[i] == '\0') {
-                strcpy(symbol->errtxt, "219: NULL characters not permitted in GS1 mode");
-                error_tag(symbol->errtxt, ZINT_ERROR_INVALID_DATA);
-                return ZINT_ERROR_INVALID_DATA;
-            }
-        }
-        if (gs1_compliant(symbol->symbology) == 1) {
-            error_number = ugs1_verify(symbol, source, in_length, local_source);
-            if (error_number != 0) {
-                return error_number;
-            }
-            in_length =(int)ustrlen(local_source);
-        } else {
-            strcpy(symbol->errtxt, "220: Selected symbology does not support GS1 mode");
-            error_tag(symbol->errtxt, ZINT_ERROR_INVALID_OPTION);
-            return ZINT_ERROR_INVALID_OPTION;
-        }
-    } else {
-        memcpy(local_source, source, in_length);
-        local_source[in_length] = '\0';
+    if ((symbol->dot_size < 0.01) || (symbol->dot_size > 20.0)) {
+        strcpy(symbol->errtxt, "221: Invalid dot size");
+        error_number = ZINT_ERROR_INVALID_OPTION;
     }
 
+    if (error_number > 4) {
+        error_tag(symbol->errtxt, error_number);
+        return error_number;
+    } else {
+        error_buffer = error_number;
+    }
+
+    memcpy(local_source, source, in_length);
+    local_source[in_length] = '\0';
+
+    /* Start acting on input mode */
     if (input_mode & ESCAPE_MODE) {
         error_number = escape_char_process(symbol, local_source, &in_length);
         if (error_number != 0) {
@@ -1189,6 +1166,30 @@ int ZBarcode_Encode(struct zint_symbol *symbol, const unsigned char *source, int
         input_mode -= ESCAPE_MODE;
     }
 
+    if ((input_mode == GS1_MODE) || (check_force_gs1(symbol->symbology))) {
+        if (gs1_compliant(symbol->symbology) == 1) {
+            // Reduce input for composite and non-forced symbologies, others (EAN128 and RSS_EXP based) will handle it themselves
+            if (is_composite(symbol->symbology) || !check_force_gs1(symbol->symbology)) {
+#ifndef _MSC_VER
+                char reduced[in_length + 1];
+#else
+                char* reduced = (char*) _alloca(in_length + 1);
+#endif
+                error_number = gs1_verify(symbol, local_source, in_length, reduced);
+                if (error_number != 0) {
+                    error_tag(symbol->errtxt, error_number);
+                    return error_number;
+                }
+                ustrcpy(local_source, reduced); // Cannot contain nul char
+                in_length = (int) ustrlen(local_source);
+            }
+        } else {
+            strcpy(symbol->errtxt, "220: Selected symbology does not support GS1 mode");
+            error_tag(symbol->errtxt, ZINT_ERROR_INVALID_OPTION);
+            return ZINT_ERROR_INVALID_OPTION;
+        }
+    }
+
     if ((input_mode < 0) || (input_mode > 2)) {
         input_mode = DATA_MODE;
     }
@@ -1200,12 +1201,6 @@ int ZBarcode_Encode(struct zint_symbol *symbol, const unsigned char *source, int
     if (input_mode == UNICODE_MODE) {
         strip_bom(local_source, &in_length);
     }
-
-    if ((symbol->dot_size < 0.01) || (symbol->dot_size > 20.0)) {
-        strcpy(symbol->errtxt, "221: Invalid dot size");
-        error_tag(symbol->errtxt, ZINT_ERROR_INVALID_OPTION);
-        return ZINT_ERROR_INVALID_OPTION;
-    }
     
     switch (symbol->symbology) {
         case BARCODE_QRCODE:
@@ -1238,7 +1233,7 @@ int ZBarcode_Encode(struct zint_symbol *symbol, const unsigned char *source, int
 #endif
                     size_t temp_len = in_length;
                     memcpy(temp, local_source, temp_len);
-					temp[temp_len] = '\0';
+                    temp[temp_len] = '\0';
                     error_number = utf_to_eci(symbol->eci, local_source, temp, &temp_len);
                     if (error_number == 0) {
                         in_length = (int) temp_len;
diff --git a/backend/rss.c b/backend/rss.c
index 0dae4bf0..c9d8644c 100644
--- a/backend/rss.c
+++ b/backend/rss.c
@@ -29,6 +29,7 @@
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
  */
+/* vim: set ts=4 sw=4 et : */
 
 /* The functions "combins" and "getRSSwidths" are copyright BSI and are
    released with permission under the following terms:
@@ -1865,14 +1866,20 @@ int rssexpanded(struct zint_symbol *symbol, unsigned char source[], int src_len)
     int check_char, c_odd, c_even, elements[235], pattern_width, reader, writer;
     int separator_row;
 #ifndef _MSC_VER
-    char binary_string[(7 * src_len) + 1];
+    char reduced[src_len + 1], binary_string[(7 * src_len) + 1];
 #else
+    char* reduced = (char*) _alloca(src_len + 1);
     char* binary_string = (char*) _alloca((7 * src_len) + 1);
 #endif
 
     separator_row = 0;
     reader = 0;
 
+    i = gs1_verify(symbol, source, src_len, reduced);
+    if (i != 0) {
+        return i;
+    }
+
     if ((symbol->symbology == BARCODE_RSS_EXP_CC) || (symbol->symbology == BARCODE_RSS_EXPSTACK_CC)) {
         /* make space for a composite separator pattern */
         separator_row = symbol->rows;
@@ -1888,7 +1895,7 @@ int rssexpanded(struct zint_symbol *symbol, unsigned char source[], int src_len)
         strcat(binary_string, "0");
     }
 
-    i = rss_binary_string(symbol, (char *) source, binary_string);
+    i = rss_binary_string(symbol, reduced, binary_string);
     if (i != 0) {
         return i;
     }
diff --git a/backend/tests/CMakeLists.txt b/backend/tests/CMakeLists.txt
index 9c4a620b..4fef7e19 100644
--- a/backend/tests/CMakeLists.txt
+++ b/backend/tests/CMakeLists.txt
@@ -49,7 +49,9 @@ endmacro(zint_add_test)
 zint_add_test(channel, test_channel)
 zint_add_test(composite, test_composite)
 zint_add_test(eci, test_eci)
+zint_add_test(gs1, test_gs1)
 zint_add_test(imail, test_imail)
+zint_add_test(library, test_library)
 zint_add_test(mailmark, test_mailmark)
 zint_add_test(maxicode, test_maxicode)
 zint_add_test(postal, test_postal)
diff --git a/backend/tests/test_gs1.c b/backend/tests/test_gs1.c
new file mode 100644
index 00000000..0a9e1580
--- /dev/null
+++ b/backend/tests/test_gs1.c
@@ -0,0 +1,277 @@
+/*
+    libzint - the open source barcode library
+    Copyright (C) 2008-2019 Robin Stuart <rstuart114@gmail.com>
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+    3. Neither the name of the project nor the names of its contributors
+       may be used to endorse or promote products derived from this software
+       without specific prior written permission.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+ */
+/* vim: set ts=4 sw=4 et : */
+
+#include "testcommon.h"
+
+//#define TEST_GS1_REDUCE_GENERATE_EXPECTED
+
+/*
+ * Check that EAN128 and RSS_EXP based symbologies reduce GS1 data
+ */
+static void test_gs1_reduce(void)
+{
+    testStart("");
+
+    int ret;
+    struct item {
+        int symbology;
+        int input_mode;
+        unsigned char* data;
+        unsigned char* primary;
+        int ret;
+
+        char* comment;
+        unsigned char* expected;
+    };
+    struct item data[] = {
+        /* 0*/ { BARCODE_EAN128, -1, "12345678901234", "", ZINT_ERROR_INVALID_DATA, "GS1 data required", "" },
+        /* 1*/ { BARCODE_EAN128, -1, "[01]12345678901234", "", 0, "Input mode ignored",
+                    "11010011100111101011101100110110010110011100100010110001110001011011000010100110111101101011001110010001011000111010111101100011101011"
+               },
+        /* 2*/ { BARCODE_EAN128, GS1_MODE, "[01]12345678901234", "", 0, "Input mode ignored",
+                    "11010011100111101011101100110110010110011100100010110001110001011011000010100110111101101011001110010001011000111010111101100011101011"
+               },
+        /* 3*/ { BARCODE_EAN128, UNICODE_MODE, "[01]12345678901234", "", 0, "Input mode ignored",
+                    "11010011100111101011101100110110010110011100100010110001110001011011000010100110111101101011001110010001011000111010111101100011101011"
+               },
+        /* 4*/ { BARCODE_EAN128_CC, -1, "[01]12345678901234", "[21]1234", 0, "Input mode ignored",
+                    "1101101110110100001000001101001100111011000010011101001100001010001100010010011011000000110110001010000000000000000000000000000000000000000000000"
+                    "1101101100111110100010011001101011100100000010011001001001111001011110011101011001000000110010001010000000000000000000000000000000000000000000000"
+                    "1101101000101111100110000101001111010000001010011001101011101110011110010011110110000110111010001010000000000000000000000000000000000000000000000"
+                    "0010110001100001010001001100100110100110001101110100111000111010010011110101100100001001010011000110111010011100010100001011010000110011100010100"
+                    "1101001110011110101110110011011001011001110010001011000111000101101100001010011011110110101100111001000101100011101011110100101111001100011101011"
+               },
+        /* 5*/ { BARCODE_EAN128_CC, GS1_MODE, "[01]12345678901234", "[21]1234", 0, "Input mode ignored",
+                    "1101101110110100001000001101001100111011000010011101001100001010001100010010011011000000110110001010000000000000000000000000000000000000000000000"
+                    "1101101100111110100010011001101011100100000010011001001001111001011110011101011001000000110010001010000000000000000000000000000000000000000000000"
+                    "1101101000101111100110000101001111010000001010011001101011101110011110010011110110000110111010001010000000000000000000000000000000000000000000000"
+                    "0010110001100001010001001100100110100110001101110100111000111010010011110101100100001001010011000110111010011100010100001011010000110011100010100"
+                    "1101001110011110101110110011011001011001110010001011000111000101101100001010011011110110101100111001000101100011101011110100101111001100011101011"
+               },
+        /* 6*/ { BARCODE_EAN128_CC, UNICODE_MODE, "[01]12345678901234", "[21]1234", 0, "Input mode ignored",
+                    "1101101110110100001000001101001100111011000010011101001100001010001100010010011011000000110110001010000000000000000000000000000000000000000000000"
+                    "1101101100111110100010011001101011100100000010011001001001111001011110011101011001000000110010001010000000000000000000000000000000000000000000000"
+                    "1101101000101111100110000101001111010000001010011001101011101110011110010011110110000110111010001010000000000000000000000000000000000000000000000"
+                    "0010110001100001010001001100100110100110001101110100111000111010010011110101100100001001010011000110111010011100010100001011010000110011100010100"
+                    "1101001110011110101110110011011001011001110010001011000111000101101100001010011011110110101100111001000101100011101011110100101111001100011101011"
+               },
+        /* 7*/ { BARCODE_EAN14, -1, "1234567890123", "", 0, "Input mode ignored",
+                    "11010011100111101011101100110110010110011100100010110001110001011011000010100110111101101011001110011011000110100001100101100011101011"
+               },
+        /* 8*/ { BARCODE_EAN14, GS1_MODE, "1234567890123", "", 0, "Input mode ignored",
+                    "11010011100111101011101100110110010110011100100010110001110001011011000010100110111101101011001110011011000110100001100101100011101011"
+               },
+        /* 9*/ { BARCODE_EAN14, UNICODE_MODE, "1234567890123", "", 0, "Input mode ignored",
+                    "11010011100111101011101100110110010110011100100010110001110001011011000010100110111101101011001110011011000110100001100101100011101011"
+               },
+        /*10*/ { BARCODE_NVE18, -1, "12345678901234567", "", 0, "Input mode ignored",
+                    "110100111001111010111011011001100101100111001000101100011100010110110000101001101111011010110011100100010110001110001011011000010010101101110001100011101011"
+               },
+        /*11*/ { BARCODE_NVE18, GS1_MODE, "12345678901234567", "", 0, "Input mode ignored",
+                    "110100111001111010111011011001100101100111001000101100011100010110110000101001101111011010110011100100010110001110001011011000010010101101110001100011101011"
+               },
+        /*12*/ { BARCODE_NVE18, UNICODE_MODE, "12345678901234567", "", 0, "Input mode ignored",
+                    "110100111001111010111011011001100101100111001000101100011100010110110000101001101111011010110011100100010110001110001011011000010010101101110001100011101011"
+               },
+        /*13*/ { BARCODE_RSS_EXP, -1, "2012", "", ZINT_ERROR_INVALID_DATA, "GS1 data required", "" },
+        /*14*/ { BARCODE_RSS_EXP, -1, "[20]12", "", 0, "Input mode ignored",
+                    "0101010100000000011011111111000010101011000000010001011111001011100010111100000000101"
+               },
+        /*15*/ { BARCODE_RSS_EXP, GS1_MODE, "[20]12", "", 0, "Input mode ignored",
+                    "0101010100000000011011111111000010101011000000010001011111001011100010111100000000101"
+               },
+        /*16*/ { BARCODE_RSS_EXP, UNICODE_MODE, "[20]12", "", 0, "Input mode ignored",
+                    "0101010100000000011011111111000010101011000000010001011111001011100010111100000000101"
+               },
+        /*17*/ { BARCODE_RSS_EXP_CC, -1, "[20]12", "[21]1234", 0, "Input mode ignored",
+                    "00110110111011010000100000110100110011101100001001110100110000101000110001001001101100000011011000101"
+                    "00110110110011111010001001100110101110010000001001100100100111100101111001110101100100000011001000101"
+                    "00110110100010111110011000010100111101000000101001100110101110111001111001001111011000011011101000101"
+                    "00001010111111111001000000001010010001100100011101101000001101000111010000111111100000000000000000000"
+                    "01010101000000000110111111110000101110011011100010010111110010111000101111000000001010000000000000000"
+               },
+        /*18*/ { BARCODE_RSS_EXP_CC, GS1_MODE, "[20]12", "[21]1234", 0, "Input mode ignored",
+                    "00110110111011010000100000110100110011101100001001110100110000101000110001001001101100000011011000101"
+                    "00110110110011111010001001100110101110010000001001100100100111100101111001110101100100000011001000101"
+                    "00110110100010111110011000010100111101000000101001100110101110111001111001001111011000011011101000101"
+                    "00001010111111111001000000001010010001100100011101101000001101000111010000111111100000000000000000000"
+                    "01010101000000000110111111110000101110011011100010010111110010111000101111000000001010000000000000000"
+               },
+        /*19*/ { BARCODE_RSS_EXP_CC, UNICODE_MODE, "[20]12", "[21]1234", 0, "Input mode ignored",
+                    "00110110111011010000100000110100110011101100001001110100110000101000110001001001101100000011011000101"
+                    "00110110110011111010001001100110101110010000001001100100100111100101111001110101100100000011001000101"
+                    "00110110100010111110011000010100111101000000101001100110101110111001111001001111011000011011101000101"
+                    "00001010111111111001000000001010010001100100011101101000001101000111010000111111100000000000000000000"
+                    "01010101000000000110111111110000101110011011100010010111110010111000101111000000001010000000000000000"
+               },
+        /*20*/ { BARCODE_RSS_EXPSTACK, -1, "12", "", ZINT_ERROR_INVALID_DATA, "GS1 data required", "" },
+        /*21*/ { BARCODE_RSS_EXPSTACK, -1, "[20]12", "", 0, "Input mode ignored",
+                    "010010000010000101101111111100001010000010000110010101111100101110001011110000000010101111100001011101"
+               },
+        /*22*/ { BARCODE_RSS_EXPSTACK, GS1_MODE, "[20]12", "", 0, "Input mode ignored",
+                    "010010000010000101101111111100001010000010000110010101111100101110001011110000000010101111100001011101"
+               },
+        /*23*/ { BARCODE_RSS_EXPSTACK, UNICODE_MODE, "[20]12", "", 0, "Input mode ignored",
+                    "010010000010000101101111111100001010000010000110010101111100101110001011110000000010101111100001011101"
+               },
+        /*24*/ { BARCODE_RSS_EXPSTACK_CC, -1, "12", "[21]1234", ZINT_ERROR_INVALID_DATA, "GS1 data required", "" },
+        /*25*/ { BARCODE_RSS_EXPSTACK_CC, -1, "[20]12", "[21]1234", 0, "Input mode ignored",
+                    "001101101110110100001000001101001100111011000010011101001100001010001100010010011011000000110110001010"
+                    "001101101100111110100010011001101011100100000010011001001001111001011110011101011001000000110010001010"
+                    "001101101000101111100110000101001111010000001010011001101011101110011110010011110110000110111010001010"
+                    "000001111111010110010000000010100100111001100001011010000011010001100100001010101001010000011110100000"
+                    "010010000000101001101111111100001011000110011110100101111100101110001011110000000010101111100001011101"
+               },
+        /*26*/ { BARCODE_RSS_EXPSTACK_CC, GS1_MODE, "[20]12", "[21]1234", 0, "Input mode ignored",
+                    "001101101110110100001000001101001100111011000010011101001100001010001100010010011011000000110110001010"
+                    "001101101100111110100010011001101011100100000010011001001001111001011110011101011001000000110010001010"
+                    "001101101000101111100110000101001111010000001010011001101011101110011110010011110110000110111010001010"
+                    "000001111111010110010000000010100100111001100001011010000011010001100100001010101001010000011110100000"
+                    "010010000000101001101111111100001011000110011110100101111100101110001011110000000010101111100001011101"
+               },
+        /*27*/ { BARCODE_RSS_EXPSTACK_CC, UNICODE_MODE, "[20]12", "[21]1234", 0, "Input mode ignored",
+                    "001101101110110100001000001101001100111011000010011101001100001010001100010010011011000000110110001010"
+                    "001101101100111110100010011001101011100100000010011001001001111001011110011101011001000000110010001010"
+                    "001101101000101111100110000101001111010000001010011001101011101110011110010011110110000110111010001010"
+                    "000001111111010110010000000010100100111001100001011010000011010001100100001010101001010000011110100000"
+                    "010010000000101001101111111100001011000110011110100101111100101110001011110000000010101111100001011101"
+               },
+    };
+    int data_size = sizeof(data) / sizeof(struct item);
+
+    char* text;
+
+    for (int i = 0; i < data_size; i++) {
+
+        struct zint_symbol* symbol = ZBarcode_Create();
+        assert_nonnull(symbol, "Symbol not created\n");
+
+        symbol->symbology = data[i].symbology;
+        if (data[i].input_mode != -1) {
+            symbol->input_mode = data[i].input_mode;
+        }
+
+        if (strlen(data[i].primary)) {
+            text = data[i].primary;
+            strcpy(symbol->primary, data[i].data);
+        } else {
+            text = data[i].data;
+        }
+        int length = strlen(text);
+
+        ret = ZBarcode_Encode(symbol, text, length);
+
+        #ifdef TEST_GS1_REDUCE_GENERATE_EXPECTED
+        if (data[i].ret == 0) {
+            printf("        /*%2d*/ { %s, %s, \"%s\", \"%s\", %d, \"%s\",\n",
+                    i, testUtilBarcodeName(data[i].symbology), testUtilInputModeName(data[i].input_mode), data[i].data, data[i].primary, data[i].ret, data[i].comment);
+            testUtilModulesDump(symbol, "                    ", "\n");
+            printf("               },\n");
+        } else {
+            printf("        /*%2d*/ { %s, %s, \"%s\", \"%s\", %s, \"%s\", \"\" },\n",
+                    i, testUtilBarcodeName(data[i].symbology), testUtilInputModeName(data[i].input_mode), data[i].data, data[i].primary, testUtilErrorName(data[i].ret), data[i].comment);
+        }
+        #else
+        assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode ret %d != %d %s\n", i, ret, data[i].ret, symbol->errtxt);
+
+        if (ret == 0) {
+            int width, row;
+            ret = testUtilModulesCmp(symbol, data[i].expected, &width, &row);
+            assert_zero(ret, "i:%d %s testUtilModulesCmp ret %d != 0 width %d row %d (%s)\n", i, testUtilBarcodeName(data[i].symbology), ret, width, row, data[i].data);
+        }
+        #endif
+
+        ZBarcode_Delete(symbol);
+    }
+
+    testFinish();
+}
+
+static void test_hrt(void)
+{
+    testStart("");
+
+    int ret;
+    struct item {
+        int symbology;
+        unsigned char* data;
+        unsigned char* primary;
+
+        unsigned char* expected;
+    };
+    // s/\/\*[ 0-9]*\*\//\=printf("\/*%2d*\/", line(".") - line("'<"))
+    struct item data[] = {
+        /* 0*/ { BARCODE_EAN128, "[01]12345678901234[20]12", "", "(01)12345678901234(20)12" },
+        /* 1*/ { BARCODE_EAN128_CC, "[01]12345678901234[20]12", "[21]12345", "(01)12345678901234(20)12" },
+        /* 2*/ { BARCODE_RSS_EXP, "[01]12345678901234[20]12", "", "(01)12345678901234(20)12" },
+        /* 3*/ { BARCODE_RSS_EXP_CC, "[01]12345678901234", "[21]12345", "(01)12345678901234" },
+        /* 4*/ { BARCODE_RSS_EXPSTACK, "[20]12", "", "(20)12" },
+        /* 5*/ { BARCODE_RSS_EXPSTACK_CC, "[20]12", "[21]12345", "(20)12" },
+    };
+    int data_size = sizeof(data) / sizeof(struct item);
+
+    char* text;
+
+    for (int i = 0; i < data_size; i++) {
+
+        struct zint_symbol* symbol = ZBarcode_Create();
+        assert_nonnull(symbol, "Symbol not created\n");
+
+        symbol->symbology = data[i].symbology;
+
+        if (strlen(data[i].primary)) {
+            text = data[i].primary;
+            strcpy(symbol->primary, data[i].data);
+        } else {
+            text = data[i].data;
+        }
+        int length = strlen(text);
+
+        ret = ZBarcode_Encode(symbol, text, length);
+        assert_zero(ret, "i:%d ZBarcode_Encode ret %d != 0 %s\n", i, ret, symbol->errtxt);
+
+        assert_zero(strcmp(symbol->text, data[i].expected), "i:%d strcmp(%s, %s) != 0\n", i, symbol->text, data[i].expected);
+
+        ZBarcode_Delete(symbol);
+    }
+
+    testFinish();
+}
+
+int main()
+{
+    test_gs1_reduce();
+    test_hrt();
+
+    testReport();
+
+    return 0;
+}
diff --git a/backend/tests/test_library.c b/backend/tests/test_library.c
new file mode 100644
index 00000000..4f8b593f
--- /dev/null
+++ b/backend/tests/test_library.c
@@ -0,0 +1,105 @@
+/*
+    libzint - the open source barcode library
+    Copyright (C) 2008-2019 Robin Stuart <rstuart114@gmail.com>
+
+    Redistribution and use in source and binary forms, with or without
+    modification, are permitted provided that the following conditions
+    are met:
+
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+    3. Neither the name of the project nor the names of its contributors
+       may be used to endorse or promote products derived from this software
+       without specific prior written permission.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+    SUCH DAMAGE.
+ */
+/* vim: set ts=4 sw=4 et : */
+
+#include "testcommon.h"
+
+static void test_checks(void)
+{
+    testStart("");
+
+    int ret;
+    struct item {
+        int symbology;
+        unsigned char* data;
+        int length;
+        int input_mode;
+        int eci;
+        float dot_size;
+        int ret;
+
+        char* expected;
+    };
+    // s/\/\*[ 0-9]*\*\//\=printf("\/*%2d*\/", line(".") - line("'<"))
+    struct item data[] = {
+        /* 0*/ { BARCODE_CODE128, "1234", -1, -1, 3, -1, ZINT_ERROR_INVALID_OPTION, "Error 217: Symbology does not support ECI switching" },
+        /* 1*/ { BARCODE_CODE128, "1234", -1, -1, 0, -1, 0, "" },
+        /* 2*/ { BARCODE_QRCODE, "1234", -1, -1, 3, -1, 0, "" },
+        /* 3*/ { BARCODE_QRCODE, "1234", -1, -1, 999999 + 1, -1, ZINT_ERROR_INVALID_OPTION, "Error 218: Invalid ECI mode" },
+        /* 4*/ { BARCODE_CODE128, "1234", -1, -1, -1, 20.1, ZINT_ERROR_INVALID_OPTION, "Error 221: Invalid dot size" },
+        /* 5*/ { BARCODE_CODE128, "1234", -1, GS1_MODE, -1, -1, ZINT_ERROR_INVALID_OPTION, "Error 220: Selected symbology does not support GS1 mode" },
+        /* 6*/ { BARCODE_EAN128, "[21]12\0004", 8, GS1_MODE, -1, -1, ZINT_ERROR_INVALID_DATA, "Error 262: NUL characters not permitted in GS1 mode" },
+        /* 7*/ { BARCODE_EAN128, "[21]12é4", -1, GS1_MODE, -1, -1, ZINT_ERROR_INVALID_DATA, "Error 250: Extended ASCII characters are not supported by GS1" },
+        /* 8*/ { BARCODE_EAN128, "[21]12\0074", -1, GS1_MODE, -1, -1, ZINT_ERROR_INVALID_DATA, "Error 251: Control characters are not supported by GS1" },
+        /* 9*/ { BARCODE_EAN128, "[21]1234", -1, GS1_MODE, -1, -1, 0, "" },
+    };
+    int data_size = sizeof(data) / sizeof(struct item);
+
+    char* text;
+    char* primary;
+    char escaped_primary[1024];
+
+    for (int i = 0; i < data_size; i++) {
+
+        struct zint_symbol* symbol = ZBarcode_Create();
+        assert_nonnull(symbol, "Symbol not created\n");
+
+        symbol->symbology = data[i].symbology;
+        if (data[i].input_mode != -1) {
+            symbol->input_mode = data[i].input_mode;
+        }
+        if (data[i].eci != -1) {
+            symbol->eci = data[i].eci;
+        }
+        if (data[i].dot_size != -1) {
+            symbol->dot_size = data[i].dot_size;
+        }
+        int length = data[i].length == -1 ? strlen(data[i].data) : data[i].length;
+
+        ret = ZBarcode_Encode(symbol, data[i].data, length);
+        assert_equal(ret, data[i].ret, "i:%d ZBarcode_Encode(%d) ret %d != %d (%s)\n", i, data[i].symbology, ret, data[i].ret, symbol->errtxt);
+
+        ret = strcmp(symbol->errtxt, data[i].expected);
+        assert_zero(ret, "i:%d (%d) strcmp(%s, %s) %d != 0\n", i, data[i].symbology, symbol->errtxt, data[i].expected, ret);
+
+        ZBarcode_Delete(symbol);
+    }
+
+    testFinish();
+}
+
+int main()
+{
+    test_checks();
+
+    testReport();
+
+    return 0;
+}
diff --git a/backend/tests/testcommon.c b/backend/tests/testcommon.c
index 58da0834..b53bb151 100644
--- a/backend/tests/testcommon.c
+++ b/backend/tests/testcommon.c
@@ -27,6 +27,7 @@
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
  */
+/* vim: set ts=4 sw=4 et : */
 /*
  * Adapted from qrencode/tests/common.c
  * Copyright (C) 2006-2017 Kentaro Fukuchi <kentaro@fukuchi.org>
@@ -252,11 +253,10 @@ char* testUtilBarcodeName(int symbology) {
         { BARCODE_GRIDMATRIX, "BARCODE_GRIDMATRIX", 142 },
         { BARCODE_UPNQR, "BARCODE_UPNQR", 143 },
         { BARCODE_ULTRA, "BARCODE_ULTRA", 144 },
-        { -1, "", 145 },
     };
     int data_size = sizeof(data) / sizeof(struct item);
 
-    if (symbology < 0 || symbology > data_size) {
+    if (symbology < 0 || symbology >= data_size) {
         return "";
     }
     if (data[symbology].val != symbology || (data[symbology].define != -1 && data[symbology].define != symbology)) { // Self-check
@@ -266,6 +266,69 @@ char* testUtilBarcodeName(int symbology) {
     return data[symbology].name;
 }
 
+char* testUtilErrorName(int error_number) {
+    struct item {
+        int define;
+        char* name;
+        int val;
+    };
+    struct item data[] = {
+        { -1, "", 0 },
+        { -1, "", 1 },
+        { ZINT_WARN_INVALID_OPTION, "ZINT_WARN_INVALID_OPTION", 2 },
+        { ZINT_WARN_USES_ECI, "ZINT_WARN_USES_ECI", 3 },
+        { -1, "", 4 },
+        { ZINT_ERROR_TOO_LONG, "ZINT_ERROR_TOO_LONG", 5 },
+        { ZINT_ERROR_INVALID_DATA, "ZINT_ERROR_INVALID_DATA", 6 },
+        { ZINT_ERROR_INVALID_CHECK, "ZINT_ERROR_INVALID_CHECK", 7 },
+        { ZINT_ERROR_INVALID_OPTION, "ZINT_ERROR_INVALID_OPTION", 8 },
+        { ZINT_ERROR_ENCODING_PROBLEM, "ZINT_ERROR_ENCODING_PROBLEM", 9 },
+        { ZINT_ERROR_FILE_ACCESS, "ZINT_ERROR_FILE_ACCESS", 10 },
+        { ZINT_ERROR_MEMORY, "ZINT_ERROR_MEMORY", 11 },
+    };
+    int data_size = sizeof(data) / sizeof(struct item);
+
+    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
+        fprintf(stderr, "testUtilErrorName data table out of sync (%d)\n", error_number);
+        abort();
+    }
+    return data[error_number].name;
+}
+
+char* testUtilInputModeName(int input_mode) {
+    struct item {
+        int define;
+        char* name;
+        int val;
+    };
+    struct item data[] = {
+        { DATA_MODE, "DATA_MODE", 0 },
+        { UNICODE_MODE, "UNICODE_MODE", 1 },
+        { GS1_MODE, "GS1_MODE", 2 },
+        { -1, "", 3 },
+        { -1, "", 4 },
+        { -1, "", 5 },
+        { -1, "", 6 },
+        { -1, "", 7 },
+        { DATA_MODE | ESCAPE_MODE, "DATA_MODE | ESCAPE_MODE", 8 },
+        { UNICODE_MODE | ESCAPE_MODE, "UNICODE_MODE | ESCAPE_MODE", 9 },
+        { GS1_MODE | ESCAPE_MODE, "GS1_MODE | ESCAPE_MODE", 10 },
+    };
+    int data_size = sizeof(data) / sizeof(struct item);
+
+    if (input_mode < 0 || input_mode >= data_size) {
+        return input_mode == -1 ? "-1" : "";
+    }
+    if (data[input_mode].val != input_mode || (data[input_mode].define != -1 && data[input_mode].define != input_mode)) { // Self-check
+        fprintf(stderr, "testUtilInputModeName data table out of sync (%d)\n", input_mode);
+        abort();
+    }
+    return data[input_mode].name;
+}
+
 int testUtilDAFTConvert(const struct zint_symbol* symbol, char* buffer, int buffer_size)
 {
     buffer[0] = '\0';
diff --git a/backend/tests/testcommon.h b/backend/tests/testcommon.h
index 90a9b644..cd0f19c5 100644
--- a/backend/tests/testcommon.h
+++ b/backend/tests/testcommon.h
@@ -27,6 +27,7 @@
     OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     SUCH DAMAGE.
  */
+/* vim: set ts=4 sw=4 et : */
 /*
  * Adapted from qrencode/tests/common.h
  * Copyright (C) 2006-2017 Kentaro Fukuchi <kentaro@fukuchi.org>
@@ -66,6 +67,8 @@ void testReport();
 extern void vector_free(struct zint_symbol *symbol); /* Free vector structures */
 
 char* testUtilBarcodeName(int symbology);
+char* testUtilErrorName(int error_number);
+char* testUtilInputModeName(int input_mode);
 int testUtilDAFTConvert(const struct zint_symbol* symbol, char* buffer, int buffer_size);
 char* testUtilEscape(char* buffer, char* escaped, int escaped_size);
 char* testUtilReadCSVField(char* buffer, char* field, int field_size);