libtiff: Avoid wrong math du to the signed/unsigned integer type conversions. As per

https://github.com/libsdl-org/libtiff/commit/9281fdd94ec861bc18767c05ea4b578cbdfd752a

From 9281fdd94ec861bc18767c05ea4b578cbdfd752a Mon Sep 17 00:00:00 2001
From: Andrey Kiselev <[EMAIL REDACTED]>
Date: Fri, 2 Jul 2010 13:38:27 +0000
Subject: [PATCH] Avoid wrong math du to the signed/unsigned integer type
 conversions. As per bug http://bugzilla.maptools.org/show_bug.cgi?id=2207

---
 ChangeLog              |  4 ++++
 libtiff/tif_getimage.c | 12 +++++++-----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 55f8e9b7..ab365435 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2010-07-02  Andrey Kiselev  <dron@ak4719.spb.edu>
 
+	* libtiff/tif_getimage.c: Avoid wrong math du to the signed/unsigned
+	integer type conversions. As per bug
+	http://bugzilla.maptools.org/show_bug.cgi?id=2207
+
 	* tools/{tiff2bw.c, thumbnail.c, pal2rgb.c}: Fix the count for
 	WhitePoint tag as per bug
 	http://bugzilla.maptools.org/show_bug.cgi?id=2042
diff --git a/libtiff/tif_getimage.c b/libtiff/tif_getimage.c
index a3ca4328..11d59e06 100644
--- a/libtiff/tif_getimage.c
+++ b/libtiff/tif_getimage.c
@@ -1,4 +1,4 @@
-/* $Id: tif_getimage.c,v 1.63.2.5 2010-07-02 10:03:07 dron Exp $ */
+/* $Id: tif_getimage.c,v 1.63.2.6 2010-07-02 13:38:27 dron Exp $ */
 
 /*
  * Copyright (c) 1991-1997 Sam Leffler
@@ -1846,6 +1846,7 @@ DECLAREContigPutFunc(putcontig8bitYCbCr41tile)
 DECLAREContigPutFunc(putcontig8bitYCbCr22tile)
 {
 	uint32* cp2;
+	int32 incr = 2*toskew+w;
 	(void) y;
 	fromskew = (fromskew / 2) * 6;
 	cp2 = cp+w+toskew;
@@ -1872,8 +1873,8 @@ DECLAREContigPutFunc(putcontig8bitYCbCr22tile)
 			cp2 ++ ;
 			pp += 6;
 		}
-		cp += toskew*2+w;
-		cp2 += toskew*2+w;
+		cp += incr;
+		cp2 += incr;
 		pp += fromskew;
 		h-=2;
 	}
@@ -1939,6 +1940,7 @@ DECLAREContigPutFunc(putcontig8bitYCbCr21tile)
 DECLAREContigPutFunc(putcontig8bitYCbCr12tile)
 {
 	uint32* cp2;
+	int32 incr = 2*toskew+w;
 	(void) y;
 	fromskew = (fromskew / 2) * 4;
 	cp2 = cp+w+toskew;
@@ -1953,8 +1955,8 @@ DECLAREContigPutFunc(putcontig8bitYCbCr12tile)
 			cp2 ++;
 			pp += 4;
 		} while (--x);
-		cp += toskew*2+w;
-		cp2 += toskew*2+w;
+		cp += incr;
+		cp2 += incr;
 		pp += fromskew;
 		h-=2;
 	}