Improve reliability of hotplugging window managers

* src/xterm.c (x_make_frame_visible): Change the user time
window if the window manager supports something different from
what it did the first time the frame was made visible.

diff --git a/src/xterm.c b/src/xterm.c
index 5b97da36ba19d4d7cb010572484a7a1ce6545ac7..abfad61041da7ae1e2015af6ffd8898cb449a8a9 100644 (file)
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -14534,21 +14534,36 @@ x_make_frame_visible (struct frame *f)
 #ifndef USE_GTK
       output = FRAME_X_OUTPUT (f);
 
-      if (output->user_time_window == None)
+      if (!x_wm_supports (f, dpyinfo->Xatom_net_wm_user_time_window))
        {
-         XSetWindowAttributes attrs;
-         memset (&attrs, 0, sizeof attrs);
-
-         output->user_time_window
-           = FRAME_OUTER_WINDOW (f);
-
-         if (x_wm_supports (f, dpyinfo->Xatom_net_wm_user_time_window))
+         if (output->user_time_window == None)
+           output->user_time_window = FRAME_OUTER_WINDOW (f);
+         else if (output->user_time_window != FRAME_OUTER_WINDOW (f))
+           {
+             XDestroyWindow (dpyinfo->display,
+                             output->user_time_window);
+             XDeleteProperty (dpyinfo->display,
+                              FRAME_OUTER_WINDOW (f),
+                              dpyinfo->Xatom_net_wm_user_time_window);
+             output->user_time_window = FRAME_OUTER_WINDOW (f);
+           }
+       }
+      else
+       {
+         if (output->user_time_window == FRAME_OUTER_WINDOW (f)
+             || output->user_time_window == None)
            {
+             XSetWindowAttributes attrs;
+             memset (&attrs, 0, sizeof attrs);
+
              output->user_time_window
                = XCreateWindow (dpyinfo->display, FRAME_X_WINDOW (f),
                                 -1, -1, 1, 1, 0, 0, InputOnly,
                                 CopyFromParent, 0, &attrs);
 
+             XDeleteProperty (dpyinfo->display,
+                              FRAME_OUTER_WINDOW (f),
+                              dpyinfo->Xatom_net_wm_user_time);
              XChangeProperty (dpyinfo->display,
                               FRAME_OUTER_WINDOW (f),
                               dpyinfo->Xatom_net_wm_user_time_window,