MTInteractiveShell.runsource() - return immediately if we are being killed (code would never get run -> deadlock)

IPython/Shell.py

@@ -385,6 +385,10 b' class MTInteractiveShell(InteractiveShell):'
             KBINT = False
             return False
         
+        if self._kill:
+            # can't queue new code if we are being killed
+            return True
+        
         try:
             code = self.compile(source, filename, symbol)
         except (OverflowError, SyntaxError, ValueError):