diff options
Diffstat (limited to 'third_party/libtiff/tif_fax3.c')
| -rw-r--r-- | third_party/libtiff/tif_fax3.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/third_party/libtiff/tif_fax3.c b/third_party/libtiff/tif_fax3.c index 087cedddc1..5fd514118c 100644 --- a/third_party/libtiff/tif_fax3.c +++ b/third_party/libtiff/tif_fax3.c @@ -1,4 +1,4 @@ -/* $Id: tif_fax3.c,v 1.80 2017-04-27 19:50:01 erouault Exp $ */ +/* $Id: tif_fax3.c,v 1.81 2017-06-18 10:31:50 erouault Exp $ */ /* * Copyright (c) 1990-1997 Sam Leffler @@ -1043,7 +1043,11 @@ Fax3Encode2DRow(TIFF* tif, unsigned char* bp, unsigned char* rp, uint32 bits) for (;;) { b2 = finddiff2(rp, b1, bits, PIXEL(rp,b1)); if (b2 >= a1) { - int32 d = b1 - a1; + /* Naive computation triggers -fsanitize=undefined,unsigned-integer-overflow */ + /* although it is correct unless the difference between both is < 31 bit */ + /* int32 d = b1 - a1; */ + int32 d = (b1 >= a1 && b1 - a1 <= 3U) ? (int32)(b1 - a1): + (b1 < a1 && a1 - b1 <= 3U) ? -(int32)(a1 - b1) : 0x7FFFFFFF; if (!(-3 <= d && d <= 3)) { /* horizontal mode */ a2 = finddiff2(bp, a1, bits, PIXEL(bp,a1)); putcode(tif, &horizcode); |