1 files changed, 17 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/basic/typeMonitorSingleton.js b/js/src/jit-test/tests/basic/typeMonitorSingleton.js
new file mode 100644
index 0000000000..be01dcaeb4
--- /dev/null
+++ b/js/src/jit-test/tests/basic/typeMonitorSingleton.js
@@ -0,0 +1,17 @@
+// |jit-test| error: TypeError
+
+var x = {f:20};
+
+function foo() {
+  for (var i = 0; i < 10; i++)
+    x.f;
+}
+foo();
+
+gc();
+
+// a type barrier needs to be generated for the access on x within foo,
+// even though its type set is initially empty after the GC.
+x = undefined;
+
+foo();