Handle case where GB2312 isn't supported; don't support Hanzi mode QR…

… codes in this case
zxing · Sep 20, 2022 · a6273e3 · a6273e3
1 parent 6fb399b
commit a6273e3
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Showing 2 changed files with 16 additions and 1 deletion.
diff --git a/core/src/main/java/com/google/zxing/common/StringUtils.java b/core/src/main/java/com/google/zxing/common/StringUtils.java
@@ -18,6 +18,7 @@
 
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
+import java.nio.charset.UnsupportedCharsetException;
 import java.util.Map;
 
 import com.google.zxing.DecodeHintType;
@@ -32,7 +33,17 @@ public final class StringUtils {
 
   private static final Charset PLATFORM_DEFAULT_ENCODING = Charset.defaultCharset();
   public static final Charset SHIFT_JIS_CHARSET = Charset.forName("SJIS");
-  public static final Charset GB2312_CHARSET = Charset.forName("GB2312");
+  public static final Charset GB2312_CHARSET;
+  static {
+    Charset gb2312Charset;
+    try {
+      gb2312Charset = Charset.forName("GB2312");
+    } catch (UnsupportedCharsetException ucee) {
+      // Can happen on some embedded JREs?
+      gb2312Charset = null;
+    }
+    GB2312_CHARSET = gb2312Charset;
+  }
   private static final Charset EUC_JP = Charset.forName("EUC_JP");
   private static final boolean ASSUME_SHIFT_JIS =
       SHIFT_JIS_CHARSET.equals(PLATFORM_DEFAULT_ENCODING) ||

diff --git a/core/src/main/java/com/google/zxing/qrcode/decoder/DecodedBitStreamParser.java b/core/src/main/java/com/google/zxing/qrcode/decoder/DecodedBitStreamParser.java
@@ -175,6 +175,10 @@ static DecoderResult decode(byte[] bytes,
   private static void decodeHanziSegment(BitSource bits,
                                          StringBuilder result,
                                          int count) throws FormatException {
+    if (StringUtils.GB2312_CHARSET == null) {
+      // Not supported without charset support
+      throw FormatException.getFormatInstance();
+    }
     // Don't crash trying to read more bits than we have available.
     if (count * 13 > bits.available()) {
       throw FormatException.getFormatInstance();