Handle drawing and server commands in lockstep

Instead of first handling all server commands in one go and then passing
it on to the command handler, since that can cause desync for streamed
resets. Now they get handled in the order that they arrive.

Author: askmeaboutlo0m

src/libclient/net/client.cpp

@@ -324,12 +324,19 @@ void Client::handleMessages(int count, net::Message *msgs)
 		m_catchupTimer->stop();
 	}
 
+	int handled = 0;
 	for(int i = 0; i < count; ++i) {
 		net::Message &msg = msgs[i];
 		switch(msg.type()) {
-		case DP_MSG_SERVER_COMMAND:
+		case DP_MSG_SERVER_COMMAND: {
+			int handleCount = i - handled;
+			if(handleCount > 0) {
+				m_commandHandler->handleCommands(handleCount, msgs + handled);
+			}
+			handled = i;
 			handleServerReply(ServerReply::fromMessage(msg), i);
 			break;
+		}
 		case DP_MSG_DATA:
 			handleData(msg);
 			break;
@@ -344,7 +351,11 @@ void Client::handleMessages(int count, net::Message *msgs)
 			break;
 		}
 	}
-	m_commandHandler->handleCommands(count, msgs);
+
+	int handleCount = count - handled;
+	if(handleCount > 0) {
+		m_commandHandler->handleCommands(handleCount, msgs + handled);
+	}
 
 	// The server can send a "catchup" message when there is a significant
 	// number of messages queued. During login, we can show a progress bar and