* TThread, Windows implementation: prevent resource leak when destroying an initially suspended and never resumed thread. The thread must be always resumed so that ThreadProc can complete and cleanup. Fixes Mantis #17560.

git-svn-id: trunk@16290 -

rtl/objpas/classes/classes.inc

@@ -90,7 +90,11 @@ function ThreadProc(ThreadObjPtr: Pointer): PtrInt;
     //  will call the AfterConstruction method in all cases)
 //    Thread.Suspend;
     try
-      Thread.Execute;
+      { The thread may be already terminated at this point, e.g. if it was intially
+        suspended, or if it wasn't ever scheduled for execution for whatever reason.
+        So bypass user code if terminated. }
+      if not Thread.Terminated then
+        Thread.Execute;
     except
       Thread.FFatalException := TObject(AcquireExceptionObject);
     end;

rtl/win/tthread.inc

@@ -30,9 +30,16 @@ destructor TThread.Destroy;
 begin
   if FHandle<>0 then
     begin
-      if not FFinished and not Suspended then
+      { Don't check Suspended. If the thread has been externally suspended (which is
+        deprecated and strongly discouraged), it's better to deadlock here than
+        to silently free the object and leave OS resources leaked. }
+      if not FFinished {and not Suspended} then
         begin
           Terminate;
+          { Allow the thread function to perform the necessary cleanup. Since
+            we've just set Terminated flag, it won't call Execute. }
+          if FInitialSuspended then
+            Start;
           WaitFor;
         end;
       CloseHandle(FHandle);