From 458923c3cd7afd60d214f1f130b1f97320fe74dc Mon Sep 17 00:00:00 2001
From: Sean Owen <sowen@cloudera.com>
Date: Wed, 31 May 2017 10:49:41 +0100
Subject: [PATCH] Closes issue #806: bad encodation switch in non-ASCII
 DataMatrix encodation (credit micjahn)

---
 .../google/zxing/datamatrix/encoder/Base256Encoder.java    | 3 ++-
 .../com/google/zxing/datamatrix/encoder/C40Encoder.java    | 3 ++-
 .../google/zxing/datamatrix/encoder/EdifactEncoder.java    | 1 +
 .../com/google/zxing/datamatrix/encoder/X12Encoder.java    | 3 ++-
 .../zxing/datamatrix/encoder/HighLevelEncodeTestCase.java  | 7 +++++++
 5 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/core/src/main/java/com/google/zxing/datamatrix/encoder/Base256Encoder.java b/core/src/main/java/com/google/zxing/datamatrix/encoder/Base256Encoder.java
index 96f66ed0b..a0f91de2c 100644
--- a/core/src/main/java/com/google/zxing/datamatrix/encoder/Base256Encoder.java
+++ b/core/src/main/java/com/google/zxing/datamatrix/encoder/Base256Encoder.java
@@ -35,7 +35,8 @@ final class Base256Encoder implements Encoder {
 
       int newMode = HighLevelEncoder.lookAheadTest(context.getMessage(), context.pos, getEncodingMode());
       if (newMode != getEncodingMode()) {
-        context.signalEncoderChange(newMode);
+        // Return to ASCII encodation, which will actually handle latch to new mode
+        context.signalEncoderChange(HighLevelEncoder.ASCII_ENCODATION);
         break;
       }
     }
diff --git a/core/src/main/java/com/google/zxing/datamatrix/encoder/C40Encoder.java b/core/src/main/java/com/google/zxing/datamatrix/encoder/C40Encoder.java
index acd02f6c8..10644d006 100644
--- a/core/src/main/java/com/google/zxing/datamatrix/encoder/C40Encoder.java
+++ b/core/src/main/java/com/google/zxing/datamatrix/encoder/C40Encoder.java
@@ -59,7 +59,8 @@ class C40Encoder implements Encoder {
       if ((count % 3) == 0) {
         int newMode = HighLevelEncoder.lookAheadTest(context.getMessage(), context.pos, getEncodingMode());
         if (newMode != getEncodingMode()) {
-          context.signalEncoderChange(newMode);
+          // Return to ASCII encodation, which will actually handle latch to new mode
+          context.signalEncoderChange(HighLevelEncoder.ASCII_ENCODATION);
           break;
         }
       }
diff --git a/core/src/main/java/com/google/zxing/datamatrix/encoder/EdifactEncoder.java b/core/src/main/java/com/google/zxing/datamatrix/encoder/EdifactEncoder.java
index dbb3f130e..3e739b4a5 100644
--- a/core/src/main/java/com/google/zxing/datamatrix/encoder/EdifactEncoder.java
+++ b/core/src/main/java/com/google/zxing/datamatrix/encoder/EdifactEncoder.java
@@ -39,6 +39,7 @@ final class EdifactEncoder implements Encoder {
 
         int newMode = HighLevelEncoder.lookAheadTest(context.getMessage(), context.pos, getEncodingMode());
         if (newMode != getEncodingMode()) {
+          // Return to ASCII encodation, which will actually handle latch to new mode
           context.signalEncoderChange(HighLevelEncoder.ASCII_ENCODATION);
           break;
         }
diff --git a/core/src/main/java/com/google/zxing/datamatrix/encoder/X12Encoder.java b/core/src/main/java/com/google/zxing/datamatrix/encoder/X12Encoder.java
index d2a555f93..79daf49fd 100644
--- a/core/src/main/java/com/google/zxing/datamatrix/encoder/X12Encoder.java
+++ b/core/src/main/java/com/google/zxing/datamatrix/encoder/X12Encoder.java
@@ -39,7 +39,8 @@ final class X12Encoder extends C40Encoder {
 
         int newMode = HighLevelEncoder.lookAheadTest(context.getMessage(), context.pos, getEncodingMode());
         if (newMode != getEncodingMode()) {
-          context.signalEncoderChange(newMode);
+          // Return to ASCII encodation, which will actually handle latch to new mode
+          context.signalEncoderChange(HighLevelEncoder.ASCII_ENCODATION);
           break;
         }
       }
diff --git a/core/src/test/java/com/google/zxing/datamatrix/encoder/HighLevelEncodeTestCase.java b/core/src/test/java/com/google/zxing/datamatrix/encoder/HighLevelEncodeTestCase.java
index 15235ff1b..df17af674 100644
--- a/core/src/test/java/com/google/zxing/datamatrix/encoder/HighLevelEncodeTestCase.java
+++ b/core/src/test/java/com/google/zxing/datamatrix/encoder/HighLevelEncodeTestCase.java
@@ -349,6 +349,13 @@ public final class HighLevelEncodeTestCase extends Assert {
     assertEquals("236 185 185 29 196 196 129 56", visualized);
   }
 
+  @Test
+  public void testEncodingWithStartAsX12AndLatchToEDIFACTInTheMiddle() {
+
+    String visualized = encodeHighLevel("*MEMANT-1F-MESTECH");
+    assertEquals("238 10 99 164 204 254 240 82 220 70 180 209 83 80 80 200", visualized);
+  }
+
   @Ignore
   @Test  
   public void testDataURL() {