1 files changed, 16 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/arrays/fillwithundefined-length-nonwriteable.js b/js/src/jit-test/tests/arrays/fillwithundefined-length-nonwriteable.js
new file mode 100644
index 0000000000..852d84116c
--- /dev/null
+++ b/js/src/jit-test/tests/arrays/fillwithundefined-length-nonwriteable.js
@@ -0,0 +1,16 @@
+var called = false;
+var a = [/* hole */, undefined, {
+    toString() {
+        if (!called) {
+            called = true;
+            a.length = 3;
+            Object.defineProperty(a, "length", {writable:false});
+        }
+        return 0;
+    }
+}, 0];
+a.sort();
+
+assertEq(a.length, 3);
+assertEq(a[1], 0);
+assertEq(a[2], undefined);