reverted one change that should have been unnecessary, comments inlin…

…e about why

src/core/thread.d

@@ -681,7 +681,7 @@ class Thread
     }
     body
     {
-        this();                 // set m_tls
+        this();
         m_fn   = fn;
         m_sz   = sz;
         m_call = Call.FN;
@@ -707,7 +707,7 @@ class Thread
     }
     body
     {
-        this();                 // set m_tls
+        this();
         m_dg   = dg;
         m_sz   = sz;
         m_call = Call.DG;
@@ -793,17 +793,7 @@ class Thread
         //       starting thread.  In effect, not doing the add here risks
         //       having thread being treated like a daemon thread.
         synchronized( slock )
-        {
-	    // when creating threads from inside a DLL, DllMain(THREAD_ATTACH)
-	    //  might be called before _beginthreadex returns, but the dll
-	    //  helper functions need to know whether the thread is created
-	    //  from the runtime itself or from another DLL or the application
-	    //  to just attach to it
-	    // as the consequence, the new Thread object is added before actual
-	    //  creation of the thread. There should be no problem with the GC
-	    //  calling thread_suspendAll, because of the slock synchronization
-            add( this );
-
+        {	    
             version( Windows )
             {
                 m_hndl = cast(HANDLE) _beginthreadex( null, m_sz, &thread_entryPoint, cast(void*) this, 0, &m_addr );
@@ -827,6 +817,15 @@ class Thread
                 if( m_tmach == m_tmach.init )
                     throw new ThreadException( "Error creating thread" );
             }
+            // NOTE: DllMain(THREAD_ATTACH) may be called before this call
+            //       exits, and this in turn calls thread_findByAddr, which
+            //       would expect this thread to be in the global list if it
+            //       is a D-created thread.  However, since thread_findByAddr
+            //       acquires Thread.slock before searching the list, it is
+            //       safe to add this thread after _beginthreadex instead
+            //       of before.  This also saves us from having to use a
+            //       scope statement to remove the thread on error.
+            add( this );
         }
     }