Description: Fix an assert when reentering ctypes function callbacks
Origin: https://bugzilla.mozilla.org/attachment.cgi?id=545444
Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=671027

--- a/mozilla/js/src/ctypes/CTypes.cpp
+++ b/mozilla/js/src/ctypes/CTypes.cpp
@@ -62,19 +62,6 @@ namespace js {
 namespace ctypes {
 
 /*******************************************************************************
-** Helper classes
-*******************************************************************************/
-
-class ScopedContextThread
-{
-public:
-  ScopedContextThread(JSContext* cx) : mCx(cx) { JS_SetContextThread(cx); }
-  ~ScopedContextThread() { JS_ClearContextThread(mCx); }
-private:
-  JSContext* mCx;
-};
-
-/*******************************************************************************
 ** JSAPI function prototypes
 *******************************************************************************/
 
@@ -2749,7 +2736,6 @@ CType::FinalizeProtoClass(JSContext* cx,
     return;
 
   JSContext* closureCx = static_cast<JSContext*>(JSVAL_TO_PRIVATE(slot));
-  JS_SetContextThread(closureCx);
   JS_DestroyContextNoGC(closureCx);
 }
 
@@ -5245,8 +5231,6 @@ CClosure::Create(JSContext* cx,
       JS_DestroyContextNoGC(cinfo->cx);
       return NULL;
     }
-
-    JS_ClearContextThread(cinfo->cx);
   }
 
 #ifdef DEBUG
@@ -5342,8 +5326,6 @@ CClosure::ClosureStub(ffi_cif* cif, void
   JSObject* thisObj = cinfo->thisObj;
   JSObject* jsfnObj = cinfo->jsfnObj;
 
-  ScopedContextThread scopedThread(cx);
-
   // Assert that we're on the thread we were created from.
   JS_ASSERT(cinfo->cxThread == JS_GetContextThread(cx));
 
--- /dev/null
+++ b/mozilla/js/src/jit-test/tests/basic/bug671027.js
@@ -0,0 +1,4 @@
+var fp_t = new ctypes.FunctionType(ctypes.default_abi, ctypes.int32_t).ptr;
+var f = fp_t(function () { return 2; });
+var g = fp_t(function () { return f() + 2; });
+assertEq(g(), 4);