From: Brian Wolff <bawolff@users.mediawiki.org>
Date: Sat, 16 Apr 2011 18:34:24 +0000 (+0000)
Subject: follow-up r86195 (Sort of). Make sure the string there can really be exploded before... 
X-Git-Tag: 1.31.0-rc.0~30773
X-Git-Url: http://git.cyclocoop.org/url?a=commitdiff_plain;h=5c3a804b6ca1657fd0de746fc7dc4dc8ebd1e33f;p=lhc%2Fweb%2Fwiklou.git

follow-up r86195 (Sort of). Make sure the string there can really be exploded before calling explode on it.

I originally had the two variables that r86195 removed there to catch the case of a malformed
png file that didn't have a null byte where it was supposed to. However, just declaring the default
for those variables wouldn't have been enough to prevent the warning from list( blah, blah) = explode(..
So now explicitly check the null byte is there like it should be.
---

diff --git a/includes/media/PNGMetadataExtractor.php b/includes/media/PNGMetadataExtractor.php
index a8a576ac42..9ee5a4a5d8 100644
--- a/includes/media/PNGMetadataExtractor.php
+++ b/includes/media/PNGMetadataExtractor.php
@@ -203,6 +203,11 @@ class PNGMetadataExtractor {
 			} elseif ( $chunk_type == 'tEXt' ) {
 				$buf = self::read( $fh, $chunk_size );
 
+				// In case there is no \x00 which will make explode fail.
+				if ( strpos( $buf, "\x00" ) === false ) {
+					throw new Exception( __METHOD__ . ": Read error on tEXt chunk" );
+				}
+
 				list( $keyword, $content ) = explode( "\x00", $buf, 2 );
 				if ( $keyword === '' || $content === '' ) {
 					throw new Exception( __METHOD__ . ": Read error on tEXt chunk" );
@@ -231,6 +236,11 @@ class PNGMetadataExtractor {
 				if ( function_exists( 'gzuncompress' ) ) {
 					$buf = self::read( $fh, $chunk_size );
 
+					// In case there is no \x00 which will make explode fail.
+					if ( strpos( $buf, "\x00" ) === false ) {
+						throw new Exception( __METHOD__ . ": Read error on zTXt chunk" );
+					}
+
 					list( $keyword, $postKeyword ) = explode( "\x00", $buf, 2 );
 					if ( $keyword === '' || $postKeyword === '' ) {
 						throw new Exception( __METHOD__ . ": Read error on zTXt chunk" );