Fixed bug introduced by the recent payload processing refactor.

IPython/frontend/qt/console/ipython_widget.py

@@ -190,6 +190,8 b' class IPythonWidget(FrontendWidget):'
         if self._previous_prompt_obj and \
                 self._previous_prompt_obj.number != previous_prompt_number:
             block = self._previous_prompt_obj.block
+
+            # Make sure the prompt block has not been erased.
             if block.isValid() and not block.text().isEmpty():
 
                 # Remove the old prompt and insert a new prompt.

IPython/frontend/qt/console/rich_ipython_widget.py

@@ -81,7 +81,7 b' class RichIPythonWidget(IPythonWidget):'
                 # Add other plot formats here!
                 return False
         else:
-            return super(RichIPythonWidget, self)._process_execute_ok(msg)
+            return super(RichIPythonWidget, self)._process_execute_payload(item)
 
     #---------------------------------------------------------------------------
     # 'RichIPythonWidget' protected interface