diff --git a/netwerk/protocol/http/HttpChannelParent.cpp b/netwerk/protocol/http/HttpChannelParent.cpp
index 3bf147d120eb..41553c0033fa 100644
--- a/netwerk/protocol/http/HttpChannelParent.cpp
+++ b/netwerk/protocol/http/HttpChannelParent.cpp
@@ -57,6 +57,7 @@
 #include "nsIApplicationCacheService.h"
 #include "nsIOfflineCacheUpdate.h"
 #include "nsIRedirectChannelRegistrar.h"
+#include "prinit.h"
 
 namespace mozilla {
 namespace net {
@@ -67,6 +68,9 @@ HttpChannelParent::HttpChannelParent(PBrowserParent* iframeEmbedding)
   , mStoredProgress(0)
   , mStoredProgressMax(0)
   , mHeadersToSyncToChild(nsnull)
+  , mSentRedirect1Begin(false)
+  , mSentRedirect1BeginFailed(false)
+  , mReceviedRedirect2Verify(false)
 {
   // Ensure gHttpHandler is initialized: we need the atom table up and running.
   nsIHttpProtocolHandler* handler;
@@ -329,6 +333,11 @@ HttpChannelParent::RecvUpdateAssociatedContentSecurity(const PRInt32& high,
   return true;
 }
 
+// Bug 621446 investigation, we don't want conditional PR_Aborts bellow to be
+// merged to a single address.
+#pragma warning(disable : 4068)
+#pragma GCC optimize ("O0")
+
 bool
 HttpChannelParent::RecvRedirect2Verify(const nsresult& result, 
                                        const RequestHeaderTuples& changedHeaders)
@@ -346,11 +355,30 @@ HttpChannelParent::RecvRedirect2Verify(const nsresult& result,
     }
   }
 
+  if (!mRedirectCallback) {
+    // Bug 621446 investigation (optimization turned off above)
+    if (mReceviedRedirect2Verify)
+      ::PR_Abort();
+    if (mSentRedirect1BeginFailed)
+      ::PR_Abort();
+    if (mSentRedirect1Begin && NS_FAILED(result))
+      ::PR_Abort();
+    if (mSentRedirect1Begin && NS_SUCCEEDED(result))
+      ::PR_Abort();
+    if (!mRedirectChannel)
+      ::PR_Abort();
+  }
+
+  mReceviedRedirect2Verify = true;
+
   mRedirectCallback->OnRedirectVerifyCallback(result);
   mRedirectCallback = nsnull;
   return true;
 }
 
+// Bug 621446 investigation
+#pragma GCC reset_options
+
 bool
 HttpChannelParent::RecvDocumentChannelCleanup()
 {
@@ -568,8 +596,14 @@ HttpChannelParent::StartRedirect(PRUint32 newChannelId,
                                    redirectFlags,
                                    responseHead ? *responseHead
                                                 : nsHttpResponseHead());
-  if (!result)
+  if (!result) {
+    // Bug 621446 investigation
+    mSentRedirect1BeginFailed = true;
     return NS_BINDING_ABORTED;
+  }
+
+  // Bug 621446 investigation
+  mSentRedirect1Begin = true;
 
   // Result is handled in RecvRedirect2Verify above
 
diff --git a/netwerk/protocol/http/HttpChannelParent.h b/netwerk/protocol/http/HttpChannelParent.h
index ab82edc095a5..0807e36cdea6 100644
--- a/netwerk/protocol/http/HttpChannelParent.h
+++ b/netwerk/protocol/http/HttpChannelParent.h
@@ -138,6 +138,10 @@ private:
 
   // used while visiting headers, to send them to child: else null
   RequestHeaderTuples *mHeadersToSyncToChild;
+
+  bool mSentRedirect1Begin : 1;
+  bool mSentRedirect1BeginFailed : 1;
+  bool mReceivedRedirect2Verify : 1;
 };
 
 } // namespace net