Merge "JpegMetadataExtractor: Allow empty segments"

diff --git a/includes/media/JpegMetadataExtractor.php b/includes/media/JpegMetadataExtractor.php
index 81722c6..9ad4097 100644 (file)
--- a/includes/media/JpegMetadataExtractor.php
+++ b/includes/media/JpegMetadataExtractor.php
@@ -155,7 +155,7 @@ class JpegMetadataExtractor {
                        } else {
                                // segment we don't care about, so skip
                                $size = wfUnpack( "nint", fread( $fh, 2 ), 2 );
-                               if ( $size['int'] <= 2 ) {
+                               if ( $size['int'] < 2 ) {
                                        throw new MWException( "invalid marker size in jpeg" );
                                }
                                fseek( $fh, $size['int'] - 2, SEEK_CUR );
@@ -173,9 +173,13 @@ class JpegMetadataExtractor {
         */
        private static function jpegExtractMarker( &$fh ) {
                $size = wfUnpack( "nint", fread( $fh, 2 ), 2 );
-               if ( $size['int'] <= 2 ) {
+               if ( $size['int'] < 2 ) {
                        throw new MWException( "invalid marker size in jpeg" );
                }
+               if ( $size['int'] === 2 ) {
+                       // fread( ..., 0 ) generates a warning
+                       return '';
+               }
                $segment = fread( $fh, $size['int'] - 2 );
                if ( strlen( $segment ) !== $size['int'] - 2 ) {
                        throw new MWException( "Segment shorter than expected" );