diff --git a/static/js/graphing.js b/static/js/graphing.js index cbb4fe0bc..7ccfcf2df 100644 --- a/static/js/graphing.js +++ b/static/js/graphing.js @@ -563,7 +563,7 @@ ImageHistoryTree.prototype.determineMaximumHeight_ = function(node) { * compact. */ ImageHistoryTree.prototype.collapseNodes_ = function(node) { - if (node.children.length == 1) { + if (node.children && node.children.length == 1) { // Keep searching downward until we find a node with more than a single child. var current = node; var previous = node;