File _service:obs_scm:CVE-2013-7353-3.patch of Package libpng12

From bec9ca9b8aa0cf16d2cde1757379afbe9adbe7d9 Mon Sep 17 00:00:00 2001
From: John Bowler <jbowler@acm.org>
Date: Thu, 17 Jan 2013 13:09:32 -0600
Subject: [PATCH] [libpng15] Revised test for validity of "num_unknowns" to
 eliminate compiler

warnings.
---
 png.h | 2 +-
 pngset.c  | 7 ++++---

diff --git a/png.h b/png.h
index db5ca8f..19768ee 100644
--- a/png.h
+++ b/png.h
@@ -786,7 +786,7 @@ defined(PNG_READ_BACKGROUND_SUPPORTED)
  defined(PNG_HANDLE_AS_UNKNOWN_SUPPORTED)
    /* Storage for unknown chunks that the library doesn't recognize. */
    png_unknown_chunkp unknown_chunks PNG_DEPSTRUCT;
-   png_uint_32 unknown_chunks_num PNG_DEPSTRUCT;
+   int unknown_chunks_num PNG_DEPSTRUCT;
 #endif

#ifdef PNG_iCCP_SUPPORTED
diff --git a/pngset.c b/pngset.c
index 6f645b42c..1c9891bd3 100644
--- a/pngset.c
+++ b/pngset.c
@@ -1040,9 +1040,10 @@ png_set_unknown_chunks(png_structp png_ptr,
       return;
 
    if (num_unknowns < 0 ||
-       num_unknowns >= INT_MAX-info_ptr->unknown_chunks_num ||
-       num_unknowns >= PNG_SIZE_MAX/png_sizeof(png_unknown_chunk)
-       - info_ptr->unknown_chunks_num)
+       num_unknowns > INT_MAX-info_ptr->unknown_chunks_num ||
+      (unsigned int)/*SAFE*/(num_unknowns +/*SAFE*/
+            info_ptr->unknown_chunks_num) >=
+         PNG_SIZE_MAX/png_sizeof(png_unknown_chunk))
       np=NULL;
 
    else
--
2.23.0