Merge "Add undefined check to revision-info"

polygerrit-ui/app/elements/shared/revision-info/revision-info.html

@@ -35,6 +35,9 @@ limitations under the License.
      * @return {Number}
      */
     RevisionInfo.prototype.getMaxParents = function() {
+      if (!this._change || !this._change.revisions) {
+        return 0;
+      }
       return Object.values(this._change.revisions)
           .reduce((acc, rev) => Math.max(rev.commit.parents.length, acc), 0);
     };
@@ -46,6 +49,9 @@ limitations under the License.
      */
     RevisionInfo.prototype.getParentCountMap = function() {
       const result = {};
+      if (!this._change || !this._change.revisions) {
+        return {};
+      }
       Object.values(this._change.revisions)
           .forEach(rev => { result[rev._number] = rev.commit.parents.length; });
       return result;