Ticket #16458: 16458.3.diff

wp-includes/media.php

@@ -462 +462 @@
                         return new WP_Error('resize_path_invalid', __( 'Resize path invalid' ));
         } else {
                 // all other formats are converted to jpg
-                $destfilename = "{$dir}/{$name}-{$suffix}.jpg";
+                if ( 'jpg' != $ext && 'jpeg' != $ext )
+                        $ext = 'jpg';
+                $destfilename = "{$dir}/{$name}-{$suffix}.$ext";
                 if ( !imagejpeg( $newimage, $destfilename, apply_filters( 'jpeg_quality', $jpeg_quality, 'image_resize' ) ) )
                         return new WP_Error('resize_path_invalid', __( 'Resize path invalid' ));
         }