don't send empty messages

src/common/connection.py

@@ -795,6 +795,8 @@ class Connection:
 	def send_message(self, jid, msg, keyID):
 		if not self.connection:
 			return
+		if not msg:
+			return
 		msgtxt = msg
 		msgenc = ''
 		if keyID and USE_GPG:

src/groupchat_window.py

@@ -495,6 +495,8 @@ class GroupchatWindow(chat.Chat):
 
 	def send_gc_message(self, message):
 		'''call this function to send our message'''
+		if not message:
+			return
 		room_jid = self.get_active_jid()
 		message_textview = self.xmls[room_jid].get_widget(
 			'message_textview')

src/tabbed_chat_window.py

@@ -304,6 +304,8 @@ class TabbedChatWindow(chat.Chat):
 
 	def send_message(self, message):
 		"""Send the message given in the args"""
+		if not message:
+			return
 		jid = self.get_active_jid()
 		conversation_textview = self.xmls[jid].get_widget('conversation_textview')
 		message_textview = self.xmls[jid].get_widget('message_textview')