Replace the workaround for bug 40663 by the real fix....

nss/mozilla/nsprpub/pr/src/md/windows/w95thred.c

 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
  *
  * The contents of this file are subject to the Mozilla Public License Version
  * 1.1 (the "License"); you may not use this file except in compliance with
  * the License. You may obtain a copy of the License at
  * http://www.mozilla.org/MPL/
  *
  * Software distributed under the License is distributed on an "AS IS" basis,
@@ skipping 291 matching lines @@
 
 PRThread*
 _MD_CURRENT_THREAD(void)
 {
 PRThread *thread;
 
         thread = _MD_GET_ATTACHED_THREAD();
 
         if (NULL == thread) {
                 thread = _PRI_AttachThread(
-            PR_SYSTEM_THREAD, PR_PRIORITY_NORMAL, NULL, 0);
+            PR_USER_THREAD, PR_PRIORITY_NORMAL, NULL, 0);
         }
         PR_ASSERT(thread != NULL);
         return thread;
 }
 
 // The following code is from Chromium src/base/thread_local_storage_win.cc,
 // r11329.
 
 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 //
@@ skipping 23 matching lines @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 // Thread Termination Callbacks.
 // Windows doesn't support a per-thread destructor with its
 // TLS primitives.  So, we build it manually by inserting a
 // function to be called on each thread's exit.
 // This magic is from http://www.codeproject.com/threads/tls.asp
 // and it works for VC++ 7.0 and later.
 
+// Force a reference to _tls_used to make the linker create the TLS directory
+// if it's not already there.  (e.g. if __declspec(thread) is not used).
+// Force a reference to p_thread_callback_nspr to prevent whole program
+// optimization from discarding the variable.
 #ifdef _WIN64
 
-// This makes the linker create the TLS directory if it's not already
-// there.  (e.g. if __declspec(thread) is not used).
 #pragma comment(linker, "/INCLUDE:_tls_used")
+#pragma comment(linker, "/INCLUDE:p_thread_callback_nspr")
 
 #else  // _WIN64
 
-// This makes the linker create the TLS directory if it's not already
-// there.  (e.g. if __declspec(thread) is not used).
 #pragma comment(linker, "/INCLUDE:__tls_used")
+#pragma comment(linker, "/INCLUDE:_p_thread_callback_nspr")
 
 #endif  // _WIN64
 
 // Static callback function to call with each thread termination.
 static void NTAPI PR_OnThreadExit(PVOID module, DWORD reason, PVOID reserved)
 {
 PRThread *me;
 
     switch (reason) {
         case DLL_PROCESS_ATTACH:
@@ skipping 15 matching lines @@
 // .CRT$XLA to .CRT$XLZ is an array of PIMAGE_TLS_CALLBACK pointers that are
 // called automatically by the OS loader code (not the CRT) when the module is
 // loaded and on thread creation. They are NOT called if the module has been
 // loaded by a LoadLibrary() call. It must have implicitly been loaded at
 // process startup.
 // By implicitly loaded, I mean that it is directly referenced by the main EXE
 // or by one of its dependent DLLs. Delay-loaded DLL doesn't count as being
 // implicitly loaded.
 //
 // See VC\crt\src\tlssup.c for reference.
+
+// The linker must not discard p_thread_callback_nspr.  (We force a reference
+// to this variable with a linker /INCLUDE:symbol pragma to ensure that.) If
+// this variable is discarded, the PR_OnThreadExit function will never be
+// called.
 #ifdef _WIN64
 
 // .CRT section is merged with .rdata on x64 so it must be constant data.
 #pragma const_seg(".CRT$XLB")
 // When defining a const variable, it must have external linkage to be sure the
-// linker doesn't discard it. If this value is discarded, the PR_OnThreadExit
-// function will never be called.
-extern const PIMAGE_TLS_CALLBACK p_thread_callback;
-const PIMAGE_TLS_CALLBACK p_thread_callback = PR_OnThreadExit;
+// linker doesn't discard it.
+extern const PIMAGE_TLS_CALLBACK p_thread_callback_nspr;
+const PIMAGE_TLS_CALLBACK p_thread_callback_nspr = PR_OnThreadExit;
 
 // Reset the default section.
 #pragma const_seg()
 
 #else  // _WIN64
 
 #pragma data_seg(".CRT$XLB")
-PIMAGE_TLS_CALLBACK p_thread_callback = PR_OnThreadExit;
+PIMAGE_TLS_CALLBACK p_thread_callback_nspr = PR_OnThreadExit;
 
 // Reset the default section.
 #pragma data_seg()
 
 #endif  // _WIN64