From d65a92b951079d315e17e20ba9e7b8423d19397e Mon Sep 17 00:00:00 2001
From: Glenn Randers-Pehrson <glennrp at users.sourceforge.net>
Date: Tue, 8 Nov 2016 16:04:08 -0600
Subject: [PATCH] [libpng16] Revert ADLER32 error handling in pngrutil.c and
 pngpread.c.

---
 ANNOUNCE   |  5 +++--
 CHANGES    |  3 ++-
 pngpread.c |  7 +------
 pngrutil.c | 10 +---------
 4 files changed, 7 insertions(+), 18 deletions(-)

diff --git a/ANNOUNCE b/ANNOUNCE
index 3a82ccf8a..4e975ff32 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,4 +1,4 @@
-Libpng 1.6.27beta02 - November 2, 2016
+Libpng 1.6.27beta02 - November 8, 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.
@@ -31,7 +31,8 @@ Version 1.6.27beta01 [November 2, 2016]
     entire PNG image instead of rejecting just the iCCP chunk with a warning,
     if built with zlib-1.2.8.1.
 
-Version 1.6.27beta02 [November 2, 2016]
+Version 1.6.27beta02 [November 8, 2016]
+  Revert ADLER32 error handling in pngrutil.c and pngpread.c.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index 064403c55..41897f67d 100644
--- a/CHANGES
+++ b/CHANGES
@@ -5760,7 +5760,8 @@ Version 1.6.27beta01 [November 2, 2016]
     entire PNG image instead of rejecting just the iCCP chunk with a warning,
     if built with zlib-1.2.8.1.
 
-Version 1.6.27beta02 [November 2, 2016]
+Version 1.6.27beta02 [November 8, 2016]
+  Revert ADLER32 error handling in pngrutil.c and pngpread.c.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/pngpread.c b/pngpread.c
index 650ba1e23..794352f42 100644
--- a/pngpread.c
+++ b/pngpread.c
@@ -684,12 +684,7 @@ png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer,
             png_warning(png_ptr, "Truncated compressed data in IDAT");
 
          else
-         {
-            if (ret == Z_DATA_ERROR)
-               png_benign_error(png_ptr, "IDAT: ADLER32 checksum mismatch");
-            else
-               png_error(png_ptr, "Decompression error in IDAT");
-         }
+            png_error(png_ptr, "Decompression error in IDAT");
 
          /* Skip the check on unprocessed input */
          return;
diff --git a/pngrutil.c b/pngrutil.c
index c49202051..b385d6e74 100644
--- a/pngrutil.c
+++ b/pngrutil.c
@@ -4108,15 +4108,7 @@ png_read_IDAT_data(png_structrp png_ptr, png_bytep output,
          png_zstream_error(png_ptr, ret);
 
          if (output != NULL)
-         {
-            if(!strncmp(png_ptr->zstream.msg,"incorrect data check",20))
-            {
-               png_chunk_benign_error(png_ptr, "ADLER32 checksum mismatch");
-               continue;
-            }
-            else
-               png_chunk_error(png_ptr, png_ptr->zstream.msg);
-         }
+            png_chunk_error(png_ptr, png_ptr->zstream.msg);
 
          else /* checking */
          {