diff -r 000000000000 -r 6474c204b198 ipc/ipdl/test/cxx/PTestHangs.ipdl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ipc/ipdl/test/cxx/PTestHangs.ipdl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,40 @@
+
+namespace mozilla {
+namespace _ipdltest {
+
+intr protocol PTestHangs {
+both:
+    intr StackFrame();
+
+parent:
+    async Nonce();
+
+child:
+    async Start();
+    intr Hang();
+    __delete__();
+
+
+state START:
+    send Start goto RACE;
+
+state RACE:
+    recv Nonce goto RACE1;
+    call StackFrame goto RACE2;
+state RACE1:
+    call StackFrame goto FRAME2;
+state RACE2:
+    recv Nonce goto FRAME2;
+
+// So as to test unwinding the RPC stack
+state FRAME2: answer StackFrame goto FRAME3;
+state FRAME3: call StackFrame goto FRAME4;
+state FRAME4: answer StackFrame goto HANG;
+state HANG:   call Hang goto DEATH;
+
+state DEATH:
+    send __delete__;
+};
+
+} // namespace _ipdltest
+} // namespace mozilla