Fix infinite loop

2 files changed, 5 insertions, 2 deletions

diff --git a/src/main/java/org/traccar/protocol/TmgFrameDecoder.java b/src/main/java/org/traccar/protocol/TmgFrameDecoder.java
index 205adaa51..8c523b533 100644
--- a/src/main/java/org/traccar/protocol/TmgFrameDecoder.java
+++ b/src/main/java/org/traccar/protocol/TmgFrameDecoder.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 - 2018 Anton Tananaev (anton@traccar.org)
+ * Copyright 2017 - 2020 Anton Tananaev (anton@traccar.org)
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -36,7 +36,7 @@ public class TmgFrameDecoder extends BaseFrameDecoder {
                         && isLetter(buffer.getByte(guessedIndex + 3))) {
                 return guessedIndex;
             }
-            guessedIndex = buffer.indexOf(guessedIndex, buffer.writerIndex(), (byte) '$');
+            guessedIndex = buffer.indexOf(guessedIndex + 1, buffer.writerIndex(), (byte) '$');
         }
         return -1;
     }
diff --git a/src/test/java/org/traccar/protocol/TmgFrameDecoderTest.java b/src/test/java/org/traccar/protocol/TmgFrameDecoderTest.java
index 4f7be1b28..c351b7775 100644
--- a/src/test/java/org/traccar/protocol/TmgFrameDecoderTest.java
+++ b/src/test/java/org/traccar/protocol/TmgFrameDecoderTest.java
@@ -10,6 +10,9 @@ public class TmgFrameDecoderTest extends ProtocolTest {
 
         TmgFrameDecoder decoder = new TmgFrameDecoder();
 
+        verifyNull(
+                decoder.decode(null, null, binary("2424242424")));
+
         verifyFrame(
                 binary("24696f662c3836343530323033373939393630342c323238323133323031372c383132343238302c302c3239393133363231362e2d3438323235383537362ca52c313337393234353339382e3831383733343637362c142c2d36393936393937332e302c313135333435343433372e2d313938363833343039322c3439323039373739392c32302c302c2d3332302c302c4c4c4c4c2c4e4e544e2c48482c302e31372c332e30312c3330313131363030312c302c56455230302e3161"),
                 decoder.decode(null, null, binary("111538360b383634353032303337393939363034eb0b1c8d00ffff23000000000000000000000000000000001c9401008c320c00188901000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000044ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff00000000000000000000000000001d940100c8950100bd0024696f662c3836343530323033373939393630342c323238323133323031372c383132343238302c302c3239393133363231362e2d3438323235383537362ca52c313337393234353339382e3831383733343637362c142c2d36393936393937332e302c313135333435343433372e2d313938363833343039322c3439323039373739392c32302c302c2d3332302c302c4c4c4c4c2c4e4e544e2c48482c302e31372c332e30312c3330313131363030312c302c56455230302e31610a000195010090960100bd0024746d702c3836343530323033373939393630342c323238323133323031372c383132343238302c302c3239393133363231362e2d3438323235383537362ca52c313337393234353339382e3831383733343637362c142c2d36393936393937332e302c313135333435343433372e2d313938363833343039322c3439323039373739392c32302c302c2d3237372c302c4c4c4c4c2c4e4e544e2c48482c302e31372c332e30312c3330313131363030312c302c56455230302e31610a00c9950100289701008b002462616b2c3836343530323033373939393630342c32313131323031372c3132303230312c312c323832362e353938312c4e2c30373731382e363436352c452c3030302e302c3239382e35322c35323834372c32322c332c2d3233392c302c4c4c4c4c2c4e4e544e2c48482c302e32342c332e30332c3330313131363030312c302c56455230302e31610a00000091960100c09701008b002462616b2c3836343530323033373939393630342c32313131323031372c3132303231322c312c323832362e353938312c4e2c30373731382e363437322c452c3030302e302c3037392e34322c35323834372c32332c332c2d3230352c302c4c4c4c4c2c4e4e544e2c48482c302e31352c332e30332c3330313131363030312c302c56455230302e31610a00000029970100589801008a002462616b2c3836343530323033373939393630342c32313131323031372c3132303232322c312c323832362e353938302c4e2c30373731382e363438352c452c3030302e302c3037372e332c35323834372c32332c332c2d3137342c302c4c4c4c4c2c4e4e544e2c48482c302e31382c332e30332c3330313131363030312c302c56455230302e31610a00000000c1970100f09801008a002462616b2c3836343530323033373939393630342c32313131323031372c3132303233312c312c323832362e353936342c4e2c30373731382e363437312c452c3030302e302c3133312e352c35323834372c32322c342c2d3134362c302c4c4c4c4c2c4e4e544e2c48482c302e31392c332e30332c3330313131363030312c302c56455230302e31610a0000000059980100889901008b002462616b2c3836343530323033373939393630342c32313131323031372c3132303234332c312c323832362e353935382c4e2c30373731382e363436382c452c3030302e302c3133392e36362c35323834372c32322c342c2d3132312c302c4c4c4c4c2c4e4e544e2c48482c302e31322c332e30332c3330313131363030312c302c56455230302e31610a000000f1980100209a01008a002462616b2c3836343530323033373939393630342c32313131323031372c3132303235332c312c323832362e353934392c4e2c30373731382e363436")));