Merge remote-tracking branch 'upstream/master' into fix/nullish-resolved

Author: P0lip

lib/resolve-external.js

@@ -44,17 +44,20 @@ function resolveExternal (parser, options) {
  * @param {string} path - The full path of `obj`, possibly with a JSON Pointer in the hash
  * @param {$Refs} $refs
  * @param {$RefParserOptions} options
+ * @param {Set} seen - Internal.
  *
  * @returns {Promise[]}
  * Returns an array of promises. There will be one promise for each JSON reference in `obj`.
  * If `obj` does not contain any JSON references, then the array will be empty.
  * If any of the JSON references point to files that contain additional JSON references,
  * then the corresponding promise will internally reference an array of promises.
  */
-function crawl (obj, path, $refs, options) {
+function crawl (obj, path, $refs, options, seen) {
+  seen = seen || new Set();
   let promises = [];
 
-  if (obj && typeof obj === "object" && !ArrayBuffer.isView(obj)) {
+  if (obj && typeof obj === "object" && !ArrayBuffer.isView(obj) && !seen.has(obj)) {
+    seen.add(obj); // Track previously seen objects to avoid infinite recursion
     if ($Ref.isExternal$Ref(obj)) {
       promises.push(resolve$Ref(obj, path, $refs, options));
     }
@@ -67,7 +70,7 @@ function crawl (obj, path, $refs, options) {
           promises.push(resolve$Ref(value, keyPath, $refs, options));
         }
         else {
-          promises = promises.concat(crawl(value, keyPath, $refs, options));
+          promises = promises.concat(crawl(value, keyPath, $refs, options, seen));
         }
       }
     }