install: don't crash if node.requiredBy is missing.

If a package has malformed metadata, this field is sometimes missing. PR-URL: npm/npm#13519 Credit: @creationix Reviewed-By: @iarna
ericmutta · Oct 20, 2016 · a40b32d · a40b32d
1 parent a55bd65
commit a40b32d
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/lib/install/mutate-into-logical-tree.js b/lib/install/mutate-into-logical-tree.js
@@ -38,7 +38,7 @@ var mutateIntoLogicalTree = module.exports = function (tree) {
 
   Object.keys(flat).sort().forEach(function (flatname) {
     var node = flat[flatname]
-    if (!node.requiredBy.length) return
+    if (!(node.requiredBy && node.requiredBy.length)) return
 
     if (node.parent) {
       // If a node is a cycle that never reaches the root of the logical