1 files changed, 17 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/basic/bug839420.js b/js/src/jit-test/tests/basic/bug839420.js
new file mode 100644
index 0000000000..66b2c87ef8
--- /dev/null
+++ b/js/src/jit-test/tests/basic/bug839420.js
@@ -0,0 +1,17 @@
+function f() {
+    var x = undefined;
+    try {
+	[1, 2, 3].map(x);
+	assertEq(0, 1);
+    } catch(e) {
+	assertEq(e.toString().includes("x is not"), true);
+    }
+
+    try {
+	[1, 2, 3].filter(x, 1, 2);
+	assertEq(0, 1);
+    } catch(e) {
+	assertEq(e.toString().includes("x is not"), true);
+    }
+}
+f();