+ if ( is_string( $wgExternalDiffEngine ) && is_executable( $wgExternalDiffEngine ) ) {
+ return $wgExternalDiffEngine;
+ } elseif ( $wgExternalDiffEngine === false && function_exists( 'wikidiff2_do_diff' ) ) {
+ return 'wikidiff2';
+ } else {
+ // Native PHP
+ return false;
+ }
+ }
+
+ /**
+ * Generates diff, to be wrapped internally in a logging/instrumentation
+ *
+ * @param string $otext Old text, must be already segmented
+ * @param string $ntext New text, must be already segmented
+ * @return bool|string
+ */
+ protected function textDiff( $otext, $ntext ) {
+ global $wgContLang;
+
+ $otext = str_replace( "\r\n", "\n", $otext );
+ $ntext = str_replace( "\r\n", "\n", $ntext );
+
+ $engine = $this->getEngine();
+