SpecialRef: fix assigning to Symbol.__proto__ returning undefined

(see HtmlUnit#15)
mozilla · Mar 15, 2024 · 96d18d4 · 96d18d4
1 parent 9cc5f6b
commit 96d18d4
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diff --git a/src/org/mozilla/javascript/SpecialRef.java b/src/org/mozilla/javascript/SpecialRef.java
@@ -114,10 +114,15 @@ public Object set(Context cx, Scriptable scope, Object value) {
                             }
 
                             final String typeOfValue = ScriptRuntime.typeof(value);
+                            if (NativeSymbol.TYPE_NAME.equals(typeOfTarget)) {
+                                return value;
+                            }
+
                             if ((value != null && !"object".equals(typeOfValue))
                                     || !"object".equals(typeOfTarget)) {
                                 return Undefined.instance;
                             }
+
                             target.setPrototype(obj);
                         } else {
                             target.setPrototype(obj);

diff --git a/testsrc/jstests/es6/proto-property.js b/testsrc/jstests/es6/proto-property.js
@@ -42,4 +42,9 @@ assertTrue(f.__proto__ === undefined);
 assertTrue({ __proto__ : [] } instanceof Array);
 assertFalse({ __proto__(){} } instanceof Function)
 
+// __proto__ on Symbol
+var x = Symbol();
+var y = { foo: "bar" }
+assertEquals({ foo: "bar" }, x.__proto__ = y);
+
 "success";