Add stop Pool and use it when dropping database

trytond/pool.py

@@ -76,6 +76,21 @@ class Pool(object):
         finally:
             Pool._lock.release()
 
+    @staticmethod
+    def stop(database_name):
+        '''
+        Stop the Pool
+        '''
+        Pool._lock.acquire()
+        lock = Pool._locks.setdefault(database_name, RLock())
+        Pool._lock.release()
+        lock.acquire()
+        if database_name in Pool._pool:
+            del Pool._pool[database_name]
+        if database_name in Pool._pools:
+            del Pool._pools[database_name]
+        lock.release()
+
     @staticmethod
     def database_list():
         '''

trytond/protocols/dispatcher.py

@@ -239,6 +239,7 @@ def drop(database_name, password):
             raise
         else:
             logger.info('DROP DB: %s' % (database_name))
+            Pool.stop(database_name)
     finally:
         cursor.close(close=True)
     return True