From 74945f2f0466a124c1cf036ca8e6339841d3f646 Mon Sep 17 00:00:00 2001
From: John Bowler <jbowler@acm.org>
Date: Mon, 13 Jun 2011 20:50:42 -0500
Subject: [PATCH] [devel] Fix and clarify LEGACY 16-to-8 scaling.

---
 pngrtran.c | 10 +++++-----
 pngtest.c  |  4 ++--
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/pngrtran.c b/pngrtran.c
index 5fb6f4840..4ed4b4c7c 100644
--- a/pngrtran.c
+++ b/pngrtran.c
@@ -1,7 +1,7 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Last changed in libpng 1.5.3 [(PENDING RELEASE)]
+ * Last changed in libpng 1.5.4 [(PENDING RELEASE)]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -2499,17 +2499,17 @@ png_do_chop(png_row_infop row_info, png_bytep row)
           *    (V * 255 + 32895) >> 16
           */
 
-#ifdef PNG_LEGACY_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
-         *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0);
-#else
          png_int_32 tmp = *sp++; /* must be signed! */
+#ifdef PNG_LEGACY_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
+         tmp += (((int)*sp++ - tmp) > 128) ? 1 : 0;
+#else
 #  ifdef PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED
          tmp += (((int)*sp++ - tmp + 128) * 65535) >> 24;
 #  else
          sp++;
 #  endif
-         *dp++ = (png_byte)tmp;
 #endif
+         *dp++ = (png_byte)tmp;
       }
 
       row_info->bit_depth = 8;
diff --git a/pngtest.c b/pngtest.c
index 2e74fc75e..515b535a2 100644
--- a/pngtest.c
+++ b/pngtest.c
@@ -1,7 +1,7 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * Last changed in libpng 1.5.3 [(PENDING RELEASE)]
+ * Last changed in libpng 1.5.4 [(PENDING RELEASE)]
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -1794,4 +1794,4 @@ main(int argc, char *argv[])
 }
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_5_4beta01 Your_png_h_is_not_version_1_5_4beta01;
+typedef png_libpng_version_1_5_4beta02 Your_png_h_is_not_version_1_5_4beta02;