patch 7.4.1318
Problem:    Channel with pipes doesn't work in GUI.
Solution:   Register input handlers for pipes.
diff --git a/src/gui_w48.c b/src/gui_w48.c
index 67274ee..6bafa8e 100644
--- a/src/gui_w48.c
+++ b/src/gui_w48.c
@@ -1780,14 +1780,15 @@
 #ifdef FEAT_CHANNEL
     if (msg.message == WM_NETBEANS)
     {
-	channel_T *channel = channel_fd2channel((sock_T)msg.wParam);
+	int	    what;
+	channel_T   *channel = channel_fd2channel((sock_T)msg.wParam, &what);
 
 	if (channel != NULL)
 	{
 	    /* Disable error messages, they can mess up the display and throw
 	     * an exception. */
 	    ++emsg_off;
-	    channel_read(channel, FALSE, "process_message");
+	    channel_read(channel, what, "process_message");
 	    --emsg_off;
 	}
 	return;