From f8a3650a7c5552b51101a375401ce0db57dedf3f Mon Sep 17 00:00:00 2001
From: Frank Warmerdam <warmerdam@pobox.com>
Date: Tue, 24 May 2011 13:35:30 +0000
Subject: [PATCH] improve error report with zero tag directories

---
 ChangeLog             | 5 +++++
 libtiff/tif_dirread.c | 8 +++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 85c5b4bc..49d2a41f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2011-05-24  Frank Warmerdam  <warmerdam@pobox.com>
+
+	* libtiff/tif_dirread.c: produce special error message for zero tag
+	directories instead of error out on the malloc(0) failure.
+
 2011-05-16  Frank Warmerdam  <warmerdam@pobox.com>
 
 	* libtiff/tif_dirinfo.c: Restore TIFFMergeFieldInfo() and
diff --git a/libtiff/tif_dirread.c b/libtiff/tif_dirread.c
index 6f96ec04..6296a1d3 100644
--- a/libtiff/tif_dirread.c
+++ b/libtiff/tif_dirread.c
@@ -1,4 +1,4 @@
-/* $Id: tif_dirread.c,v 1.167 2011-02-18 20:53:04 fwarmerdam Exp $ */
+/* $Id: tif_dirread.c,v 1.168 2011-05-24 13:35:30 fwarmerdam Exp $ */
 
 /*
  * Copyright (c) 1988-1997 Sam Leffler
@@ -4575,6 +4575,12 @@ TIFFFetchDirectory(TIFF* tif, uint64 diroff, TIFFDirEntry** pdir,
 			dircount16 = (uint16)dircount64;
 			dirsize = 20;
 		}
+		if (dircount16 == 0 )
+		{
+			TIFFErrorExt(tif->tif_clientdata, module,
+			             "Sanity check on directory count failed, zero tag directories not supported");
+			return 0;
+		}
 		origdir = _TIFFCheckMalloc(tif, dircount16,
 						dirsize,
 						"to read TIFF directory");