set busy/idle around every message

not just shell

IPython/kernel/zmq/kernelbase.py

@@ -137,6 +137,10 b' class Kernel(Configurable):'
 
         self.log.debug("Control received: %s", msg)
 
+        # Set the parent message for side effects.
+        self.set_parent(idents, msg)
+        self._publish_status(u'busy')
+        
         header = msg['header']
         msg_type = header['msg_type']
 
@@ -149,6 +153,10 b' class Kernel(Configurable):'
             except Exception:
                 self.log.error("Exception in control handler:", exc_info=True)
     
+        sys.stdout.flush()
+        sys.stderr.flush()
+        self._publish_status(u'idle')
+    
     def dispatch_shell(self, stream, msg):
         """dispatch shell requests"""
         # flush control requests first

docs/source/development/messaging.rst

@@ -894,7 +894,7 b' Message type: ``status``::'
 
 .. versionchanged:: 5.0
 
-    Busy and idle messages should be sent before/after handling every shell message,
+    Busy and idle messages should be sent before/after handling every message,
     not just execution.
 
 Clear output