From 93a3bc734337680ba936deb712ab555886d09dbe Mon Sep 17 00:00:00 2001
From: Glenn Randers-Pehrson <glennrp at users.sourceforge.net>
Date: Sat, 23 Jan 2016 10:09:18 -0600
Subject: [PATCH] [libpng16] Revised workaround for Coverity issue in
 pngvalid.c

---
 ANNOUNCE                    |  5 +++--
 CHANGES                     |  3 ++-
 contrib/libtests/pngvalid.c | 24 +++++++-----------------
 3 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/ANNOUNCE b/ANNOUNCE
index 1e4b686a3..df66424f3 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,4 +1,4 @@
-Libpng 1.6.22beta01 - January 18, 2016
+Libpng 1.6.22beta01 - January 22, 2016
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -25,7 +25,7 @@ Other information:
 
 Changes since the last public release (1.6.21):
 
-Version 1.6.22beta01 [January 18, 2016]
+Version 1.6.22beta01 [January 22, 2016]
   Changed PNG_USE_MKSTEMP to __COVERITY__ to select alternate
     "tmpfile()" implementation in contrib/libtests/pngstest.c
   Fixed NO_STDIO build of pngunknown.c to skip calling png_init_io()
@@ -38,6 +38,7 @@ Version 1.6.22beta01 [January 18, 2016]
     disallows image width/height/format that *might* overflow.  This is
     a quiet API change that limits in-memory image size (uncompressed) to
     less than 4GByte and image row size (stride) to less than 2GByte.
+  Revised workaround for false-positive Coverity issue in pngvalid.c.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index 24ff082ab..e159cc158 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5484,7 +5484,7 @@ Version 1.6.21rc02 [January 7, 2016]
 Version 1.6.21 [January 15, 2016]
   Worked around a false-positive Coverity issue in pngvalid.c.
 
-Version 1.6.22beta01 [January 18, 2016]
+Version 1.6.22beta01 [January 22, 2016]
   Changed PNG_USE_MKSTEMP to __COVERITY__ to select alternate
     "tmpfile()" implementation in contrib/libtests/pngstest.c
   Fixed NO_STDIO build of pngunknown.c to skip calling png_init_io()
@@ -5497,6 +5497,7 @@ Version 1.6.22beta01 [January 18, 2016]
     disallows image width/height/format that *might* overflow.  This is
     a quiet API change that limits in-memory image size (uncompressed) to
     less than 4GByte and image row size (stride) to less than 2GByte.
+  Revised workaround for false-positive Coverity issue in pngvalid.c.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/contrib/libtests/pngvalid.c b/contrib/libtests/pngvalid.c
index 55d094592..a32b21f2c 100644
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
@@ -1,7 +1,7 @@
 
 /* pngvalid.c - validate libpng by constructing then reading png files.
  *
- * Last changed in libpng 1.6.21 [January 15, 2016]
+ * Last changed in libpng 1.6.22 [(PENDING RELEASE)]
  * Copyright (c) 2014-2016 Glenn Randers-Pehrson
  * Written by John Cunningham Bowler
  *
@@ -309,13 +309,8 @@ static void r16(png_uint_16p p16, size_t count)
    }
 }
 
-#ifdef __COVERITY__
-#  define R16(this)\
-   r16(&(this), (sizeof (this))/2U/*(sizeof (png_uint_16))*/)
-#else
-#  define R16(this)\
-   r16(&(this), (sizeof (this))/(sizeof (png_uint_16)))
-#endif
+#define R16(this) r16(&(this), (sizeof (this))/(sizeof (png_uint_16)))
+#define R16_1(this) r16(&(this), (size_t) 1U)
 
 #if defined PNG_READ_RGB_TO_GRAY_SUPPORTED ||\
     defined PNG_READ_FILLER_SUPPORTED
@@ -331,13 +326,8 @@ static void r32(png_uint_32p p32, size_t count)
    }
 }
 
-#ifdef __COVERITY__
-#  define R32(this)\
-   r32(&(this), (sizeof (this))/4U/*(sizeof (png_uint_32))*/)
-#else
-#  define R32(this)\
-   r32(&(this), (sizeof (this))/(sizeof (png_uint_32)))
-#endif
+#define R32(this) r32(&(this), (sizeof (this))/(sizeof (png_uint_32)))
+#define R32_1(this) r32(&(this), (size_t) 1U)
 
 #endif /* READ_FILLER || READ_RGB_TO_GRAY */
 
@@ -350,7 +340,7 @@ random_mod(unsigned int max)
 {
    png_uint_16 x;
 
-   R16(x);
+   R16_1(x);
 
    return x % max; /* 0 .. max-1 */
 }
@@ -7313,7 +7303,7 @@ image_transform_png_set_rgb_to_gray_ini(const image_transform *this,
       png_uint_32 ru;
       double total;
 
-      R32(ru);
+      R32_1(ru);
       data.green_coefficient = total = (ru & 0xffff) / 65535.;
       ru >>= 16;
       data.red_coefficient = (1 - total) * (ru & 0xffff) / 65535.;