Refs #3359. Fixed toMatcherJson method to get the pattern which is what they've called query.

lib/pipeline/documentSources/MatchDocumentSource.js

@@ -74,7 +74,7 @@ proto.accept = function accept(document) {
  * @param builder the builder to write to
  **/
 proto.toMatcherJson = function toMatcherJson(builder) {
-	var q = this.matcher.query;
+	var q = this.matcher._pattern;
 	for(var k in q){
 		builder[k] = q[k];
 	}