From 87b6c95f6cc79d56034845975e74bd630f61dd78 Mon Sep 17 00:00:00 2001
From: Jim Chen <nchen@mozilla.com>
Date: Thu, 24 Jul 2014 22:33:45 -0400
Subject: [PATCH] Bug 1016629 - b. Use RAII class to assign mStackToFill;
 r=snorp

---
 xpcom/threads/ThreadStackHelper.cpp | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/xpcom/threads/ThreadStackHelper.cpp b/xpcom/threads/ThreadStackHelper.cpp
index b843eed2ba7..bb21ca152e2 100644
--- a/xpcom/threads/ThreadStackHelper.cpp
+++ b/xpcom/threads/ThreadStackHelper.cpp
@@ -109,6 +109,18 @@ ThreadStackHelper::~ThreadStackHelper()
 #endif
 }
 
+namespace {
+template <typename T>
+class ScopedSetPtr
+{
+private:
+  T*& mPtr;
+public:
+  ScopedSetPtr(T*& p, T* val) : mPtr(p) { mPtr = val; }
+  ~ScopedSetPtr() { mPtr = nullptr; }
+};
+}
+
 void
 ThreadStackHelper::GetStack(Stack& aStack)
 {
@@ -118,6 +130,8 @@ ThreadStackHelper::GetStack(Stack& aStack)
     return;
   }
 
+  ScopedSetPtr<Stack> stackPtr(mStackToFill, &aStack);
+
 #if defined(XP_LINUX)
   if (!sInitialized) {
     MOZ_ASSERT(false);
@@ -199,7 +213,6 @@ ThreadStackHelper::PrepareStackBuffer(Stack& aStack)
       !aStack.EnsureBufferCapacity(mMaxBufferSize)) {
     return false;
   }
-  mStackToFill = &aStack;
   return true;
 #else
   return false;