Restrict index not be greater than row_size in TIFF_PredictLine

core/src/fxcodec/codec/fx_codec_flate.cpp

Index: core/src/fxcodec/codec/fx_codec_flate.cpp
diff --git a/core/src/fxcodec/codec/fx_codec_flate.cpp b/core/src/fxcodec/codec/fx_codec_flate.cpp
index a12fffbe5ced0341c96cbf26a44915ffdedf01ec..f4439f271512c218ad8769c66a50fd5fd69ad67c 100644
--- a/core/src/fxcodec/codec/fx_codec_flate.cpp
+++ b/core/src/fxcodec/codec/fx_codec_flate.cpp
@@ -528,6 +528,9 @@ static void TIFF_PredictLine(FX_LPBYTE dest_buf, int row_size, int BitsPerCompon
         for(int i = 1; i < row_bits; i ++) {
             int col = i % 8;
             int index = i / 8;
+            if (index > row_size) {

[Tom Sepez, 2014/08/27 21:20:35]

Don't you want >= ? 

[Tom Sepez, 2014/08/27 21:25:45]

Maybe we prune row_bits outside the loop to avoid having to test each time.

[Bo Xu, 2014/08/27 22:13:18]

Good idea.

+                break;
+            }
             int index_pre = (col == 0) ? (index - 1) : index;

[Tom Sepez, 2014/08/27 21:25:45]

nit:  maybe these should move outsize the loop, start at (0, 0) and get assigned
to the current col, row at the bottom of the loop?

[Bo Xu, 2014/08/27 22:13:18]

Done.

             int col_pre = (col == 0) ? 8 : col;

[Tom Sepez, 2014/08/27 21:35:33]

8 seems like a weird value to assign to a variable thats normally the resuult of
i % 8 and should be in the 0..7

             if( ((dest_buf[index] >> (7 - col)) & 1) ^ ((dest_buf[index_pre] >> (8 - col_pre)) & 1) ) {

[Tom Sepez, 2014/08/27 21:35:33]

This would need to change if you followed the above comment.