From: Derk-Jan Hartman <hartman.wiki@gmail.com>
Date: Wed, 11 Sep 2019 22:12:22 +0000 (+0200)
Subject: Fix XMP parser errors due to trailing nullchar
X-Git-Tag: 1.31.4~11
X-Git-Url: http://git.heureux-cyclage.org/?p=lhc%2Fweb%2Fwiklou.git;a=commitdiff_plain;h=7668c368fda48d8a8c18ae8e223b12bafd0bd4c6

Fix XMP parser errors due to trailing nullchar

JPEG files can have trailing \0 chars at the end of the XMP value. Use
trim() to remove these from the string value.

Bug: T118799
Change-Id: Id4ab223ef432e5d2c0dd3b4e332320db02422700
(cherry picked from commit 9ce26a564d066a33ba7ae2a6502e3d57e7e4d48b)
---

diff --git a/includes/media/JpegMetadataExtractor.php b/includes/media/JpegMetadataExtractor.php
index 3c778f36c1..89fc64dc83 100644
--- a/includes/media/JpegMetadataExtractor.php
+++ b/includes/media/JpegMetadataExtractor.php
@@ -120,14 +120,17 @@ class JpegMetadataExtractor {
 				$temp = self::jpegExtractMarker( $fh );
 				// check what type of app segment this is.
 				if ( substr( $temp, 0, 29 ) === "http://ns.adobe.com/xap/1.0/\x00" && $showXMP ) {
-					$segments["XMP"] = substr( $temp, 29 );
+					// use trim to remove trailing \0 chars
+					$segments["XMP"] = trim( substr( $temp, 29 ) );
 				} elseif ( substr( $temp, 0, 35 ) === "http://ns.adobe.com/xmp/extension/\x00" && $showXMP ) {
-					$segments["XMP_ext"][] = substr( $temp, 35 );
+					// use trim to remove trailing \0 chars
+					$segments["XMP_ext"][] = trim( substr( $temp, 35 ) );
 				} elseif ( substr( $temp, 0, 29 ) === "XMP\x00://ns.adobe.com/xap/1.0/\x00" && $showXMP ) {
 					// Some images (especially flickr images) seem to have this.
 					// I really have no idea what the deal is with them, but
 					// whatever...
-					$segments["XMP"] = substr( $temp, 29 );
+					// use trim to remove trailing \0 chars
+					$segments["XMP"] = trim( substr( $temp, 29 ) );
 					wfDebug( __METHOD__ . ' Found XMP section with wrong app identifier '
 						. "Using anyways.\n" );
 				} elseif ( substr( $temp, 0, 6 ) === "Exif\0\0" ) {
diff --git a/tests/phpunit/data/media/jpeg-xmp-nullchar.jpg b/tests/phpunit/data/media/jpeg-xmp-nullchar.jpg
new file mode 100644
index 0000000000..76ae2b486c
Binary files /dev/null and b/tests/phpunit/data/media/jpeg-xmp-nullchar.jpg differ
diff --git a/tests/phpunit/includes/media/JpegMetadataExtractorTest.php b/tests/phpunit/includes/media/JpegMetadataExtractorTest.php
index c943cef906..b745152fe7 100644
--- a/tests/phpunit/includes/media/JpegMetadataExtractorTest.php
+++ b/tests/phpunit/includes/media/JpegMetadataExtractorTest.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * @todo Could use a test of extended XMP segments. Hard to find programs that
- * create example files, and creating my own in vim propbably wouldn't
+ * create example files, and creating my own in vim probably wouldn't
  * serve as a very good "test". (Adobe photoshop probably creates such files
  * but it costs money). The implementation of it currently in MediaWiki is based
  * solely on reading the standard, without any real world test files.
@@ -76,6 +76,12 @@ class JpegMetadataExtractorTest extends MediaWikiTestCase {
 		$this->assertEquals( $expected, bin2hex( $res['PSIR'][0] ) );
 	}
 
+	public function testXMPExtractionNullChar() {
+		$res = JpegMetadataExtractor::segmentSplitter( $this->filePath . 'jpeg-xmp-nullchar.jpg' );
+		$expected = file_get_contents( $this->filePath . 'jpeg-xmp-psir.xmp' );
+		$this->assertEquals( $expected, $res['XMP'] );
+	}
+
 	public function testXMPExtractionAltAppId() {
 		$res = JpegMetadataExtractor::segmentSplitter( $this->filePath . 'jpeg-xmp-alt.jpg' );
 		$expected = file_get_contents( $this->filePath . 'jpeg-xmp-psir.xmp' );