From c35378acc5c0276563f9df844a9258781aeda3e4 Mon Sep 17 00:00:00 2001
From: Robin Stuart <rstuart114@gmail.com>
Date: Fri, 22 Jul 2016 16:42:39 +0100
Subject: [PATCH] Bugfix: EDIFACT unlatch character not needed for all symbols

Ref: ISO 16022 para 5.2.8.2
Bug reported by Daniel Yang
---
 backend/dmatrix.c | 64 +++++++++++++++++++----------------------------
 1 file changed, 26 insertions(+), 38 deletions(-)

diff --git a/backend/dmatrix.c b/backend/dmatrix.c
index 79694c7c..c47fee37 100644
--- a/backend/dmatrix.c
+++ b/backend/dmatrix.c
@@ -527,7 +527,7 @@ static int dm200encode(struct zint_symbol *symbol, const unsigned char source[],
     int sp, tp, i, gs1;
     int current_mode, next_mode;
     int inputlen = *length_p;
-    int debug = 0;
+    int debug = 1;
 #ifndef _MSC_VER
     char binary[2 * inputlen];
 #else
@@ -970,7 +970,7 @@ static int dm200encode(struct zint_symbol *symbol, const unsigned char source[],
 }
 
 static int dm200encode_remainder(unsigned char target[], int target_length, const unsigned char source[], const int inputlen, const int last_mode, const int process_buffer[], const int process_p, const int symbols_left) {
-    int debug = 0;
+    int debug = 1;
 
     switch (last_mode) {
         case DM_C40:
@@ -1047,7 +1047,7 @@ static int dm200encode_remainder(unsigned char target[], int target_length, cons
             break;
 
         case DM_EDIFACT:
-            if (symbols_left == process_p) // Unlatch not required!
+            if (symbols_left <= 2) // Unlatch not required!
             {
                 if (process_p == 1) {
                     target[target_length] = source[inputlen - 1] + 1;
@@ -1060,9 +1060,28 @@ static int dm200encode_remainder(unsigned char target[], int target_length, cons
                     target[target_length] = source[inputlen - 1] + 1;
                     target_length++;
                 }
+            } else {
+                // Append edifact unlatch value (31) and encode as triple.
 
-                if (process_p == 3) // Append edifact unlatch value (31) and encode as triple.
-                {
+                if (process_p == 1) {
+                    target[target_length] = (unsigned char) ((process_buffer[0] << 2) + ((31 & 0x30) >> 4));
+                    target_length++;
+                    target[target_length] = (unsigned char) ((31 & 0x0f) << 4) ;
+                    target_length++;
+                    target[target_length] = (unsigned char) 0;
+                    target_length++;
+                }
+
+                if (process_p == 2) {
+                    target[target_length] = (unsigned char) ((process_buffer[0] << 2) + ((process_buffer[1] & 0x30) >> 4));
+                    target_length++;
+                    target[target_length] = (unsigned char) (((process_buffer[1] & 0x0f) << 4) + ((31 & 0x3c) >> 2));
+                    target_length++;
+                    target[target_length] = (unsigned char) (((31 & 0x03) << 6));
+                    target_length++;
+                }
+
+                if (process_p == 3) {
                     target[target_length] = (unsigned char) ((process_buffer[0] << 2) + ((process_buffer[1] & 0x30) >> 4));
                     target_length++;
                     target[target_length] = (unsigned char) (((process_buffer[1] & 0x0f) << 4) + ((process_buffer[2] & 0x3c) >> 2));
@@ -1070,38 +1089,7 @@ static int dm200encode_remainder(unsigned char target[], int target_length, cons
                     target[target_length] = (unsigned char) (((process_buffer[2] & 0x03) << 6) + 31);
                     target_length++;
                 }
-            }
 
-            if (symbols_left > process_p) // Unlatch and encode remaining data in ascii.
-            {
-                // Edifact unlatch.
-                if (symbols_left < 3) {
-                    target[target_length] = 31;
-                    target_length++;
-                } else
-                    target[target_length] = (31 << 2);
-                target_length++;
-
-                if (process_p == 1) {
-                    target[target_length] = source[inputlen - 1] + 1;
-                    target_length++;
-                }
-
-                if (process_p == 2) {
-                    target[target_length] = source[inputlen - 2] + 1;
-                    target_length++;
-                    target[target_length] = source[inputlen - 1] + 1;
-                    target_length++;
-                }
-
-                if (process_p == 3) {
-                    target[target_length] = source[inputlen - 3] + 1;
-                    target_length++;
-                    target[target_length] = source[inputlen - 2] + 1;
-                    target_length++;
-                    target[target_length] = source[inputlen - 1] + 1;
-                    target_length++;
-                }
             }
             break;
     }
@@ -1222,7 +1210,7 @@ int data_matrix_200(struct zint_symbol *symbol, unsigned char source[], const in
     }
     ecc200(binary, bytes, datablock, rsblock, skew);
     // Print Codewords
-#ifdef DEBUG
+//#ifdef DEBUG
     {
         int CWCount;
         if (skew)
@@ -1234,7 +1222,7 @@ int data_matrix_200(struct zint_symbol *symbol, unsigned char source[], const in
             printf(" %3i", binary[posCur]);
         puts("\n");
     }
-#endif
+//#endif
     { // placement
         int x, y, NC, NR, *places;
         NC = W - 2 * (W / FW);