NSException: Avoid re-throwing exception from within NS_HANDLER

Author: qmfrederik

Source/NSOperation.m

@@ -421,6 +421,7 @@ - (void) start
   ENTER_POOL
 
   double	prio = [NSThread  threadPriority];
+  NSException* caughtException = nil;
 
   AUTORELEASE(RETAIN(self));	// Make sure we exist while running.
   [internal->lock lock];
@@ -453,12 +454,16 @@ - (void) start
     }
   NS_HANDLER
     {
-      [internal->lock unlock];
-      [localException raise];
+      caughtException = localException;
     }
   NS_ENDHANDLER
   [internal->lock unlock];
 
+  if (caughtException != nil)
+  {
+    [caughtException raise];
+  }
+
   NS_DURING
     {
       if (NO == [self isCancelled])
@@ -470,10 +475,15 @@ - (void) start
   NS_HANDLER
     {
       [NSThread setThreadPriority:  prio];
-      [localException raise];
+      caughtException = localException;
     }
   NS_ENDHANDLER;
 
+  if (caughtException != nil)
+  {
+    [caughtException raise];
+  }
+
   [self _finish];
   LEAVE_POOL
 }