Don't wait for visible frames to become visible

For discussion, see thread starting at
https://lists.gnu.org/archive/html/emacs-devel/2018-03/msg00807.html.
* src/xterm.c (x_make_frame_visible): Check FRAME_VISIBLE_P before
calling x_wait_for_event.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/xterm.c b/src/xterm.c
index 0fcd7ef7e2b..f8ac23e53b9 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -11551,7 +11551,8 @@ x_make_frame_visible (struct frame *f)
     poll_for_input_1 ();
     poll_suppress_count = old_poll_suppress_count;
 #endif
-    x_wait_for_event (f, MapNotify);
+    if (FRAME_VISIBLE_P (f))
+      x_wait_for_event (f, MapNotify);
   }
 }