third_party/libpng/patches/0001-chunkerror.patch

From e87a02987101e2dbe319a4aba6b52470f7624b4a Mon Sep 17 00:00:00 2001
From: Leon Scroggins III <scroggo@google.com>
Date: Wed, 18 Apr 2018 21:45:46 +0000
Subject: [PATCH] Turn large PNG chunks into benign errors

Bug: 827754

A recent change to libpng [1] (included in Chromium with the recent
libpng update [2]) turns chunks that are bigger than
PNG_USER_CHUNK_MALLOC_MAX into failures. Although this matches the
intent of PNG_USER_CHUNK_MALLOC_MAX, it also causes images which used to
be viewable in Chromium to fail. Changing to a benign error allows us to
display these images once again. Though it means we do allow libpng to
allocate more than PNG_USER_CHUNK_MALLOC_MAX, it matches the behavior
prior to [2] (when we were using 1.6.22), and it does not regress
crbug.com/117369

Add a regression test. The image is supplied in the bug, and has approval
to be checked in [3].

[1] https://github.com/glennrp/libpng/commit/347538efbdc21b8df684ebd92d37400b3ce85d55
[2] https://chromium.googlesource.com/chromium/src/+/f82653a473f8de5fc86d0f2ecc75f6237e61946b
[3] https://bugs.chromium.org/p/chromium/issues/detail?id=827754#c15

Change-Id: Iaae884b42a94bdec6e1cfad97d46ef820a75a5f8
Reviewed-on: https://chromium-review.googlesource.com/1014027
Commit-Queue: Leon Scroggins <scroggo@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#551838}
---

diff --git a/third_party/libpng/pngrutil.c b/third_party/libpng/pngrutil.c
index 8692933..2210ffc 100644
--- a/third_party/libpng/pngrutil.c
+++ b/third_party/libpng/pngrutil.c
@@ -3165,7 +3165,7 @@
    {
       png_debug2(0," length = %lu, limit = %lu",
          (unsigned long)length,(unsigned long)limit);
-      png_chunk_error(png_ptr, "chunk data is too large");
+      png_benign_error(png_ptr, "chunk data is too large");
    }
 }