1 files changed, 13 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/arrays/pop-nonarray-nonwritable-length.js b/js/src/jit-test/tests/arrays/pop-nonarray-nonwritable-length.js
new file mode 100644
index 0000000000..22a5b706b5
--- /dev/null
+++ b/js/src/jit-test/tests/arrays/pop-nonarray-nonwritable-length.js
@@ -0,0 +1,13 @@
+// Array.prototype.pop does a strict assignment to this.length even if the
+// caller is nonstrict. Bug 886087.
+
+load(libdir + "asserts.js");
+
+// obj.length is read-only
+var obj = {pop: [].pop, 0: "zero"};
+Object.defineProperty(obj, "length", {configurable: true, value: 1, writable: false});
+assertThrowsInstanceOf(() => obj.pop(), TypeError);
+
+// obj.length has only a getter
+obj = {pop: [].pop, 0: "zero", get length() { return 1; }};
+assertThrowsInstanceOf(() => obj.pop(), TypeError);