1 files changed, 38 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/debug/Frame-arguments-06.js b/js/src/jit-test/tests/debug/Frame-arguments-06.js
new file mode 100644
index 000000000..3ce6f4695
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Frame-arguments-06.js
@@ -0,0 +1,38 @@
+// Test extracting frame.arguments element getters and calling them in
+// various awkward ways.
+
+load(libdir + "asserts.js");
+
+var g = newGlobal();
+var dbg = Debugger(g);
+var hits = 0;
+var fframe, farguments, fgetter;
+dbg.onDebuggerStatement = function (frame) {
+    if (hits === 0) {
+        fframe = frame;
+        farguments = frame.arguments;
+        fgetter = Object.getOwnPropertyDescriptor(farguments, "0").get;
+        assertEq(fgetter instanceof Function, true);
+
+        // Calling the getter without an appropriate this-object
+        // fails, but shouldn't assert or crash.
+        assertThrowsInstanceOf(function () { fgetter.call(Math); }, TypeError);
+    } else {
+        // Since fframe is still on the stack, fgetter can be applied to it.
+        assertEq(fframe.live, true);
+        assertEq(fgetter.call(farguments), 100);
+
+        // Since h was called without arguments, there is no argument 0.
+        assertEq(fgetter.call(frame.arguments), undefined);
+    }
+    hits++;
+};
+
+g.eval("function h() { debugger; }");
+g.eval("function f(x) { debugger; h(); }");
+g.f(100);
+assertEq(hits, 2);
+
+// Now that fframe is no longer live, trying to get its arguments should throw.
+assertEq(fframe.live, false);
+assertThrowsInstanceOf(function () { fgetter.call(farguments); }, Error);