master 1aa8780: Ignore spurious focus events

[Daniel Colascione]

branch: master
commit 1aa8780d7b3bf0b4dd227946f0c6095b2c9e545e
Author: Daniel Colascione <address@hidden>
Commit: Daniel Colascione <address@hidden>

    Ignore spurious focus events
    
    * src/xterm.c (x_detect_focus_change): Ignore FocusIn and FocusOut
    events from grabs
---
 src/xterm.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/xterm.c b/src/xterm.c
index 21d99f0..5d229e4 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -4790,6 +4790,16 @@ x_detect_focus_change (struct x_display_info *dpyinfo, 
struct frame *frame,
 
     case FocusIn:
     case FocusOut:
+      /* Ignore transient focus events from hotkeys, window manager
+         gadgets, and other odd sources.  Some buggy window managers
+         (e.g., Muffin 4.2.4) send FocusIn events of this type without
+         corresponding FocusOut events even when some other window
+         really has focus, and these kinds of focus event don't
+         correspond to real user input changes.  GTK+ uses the same
+         filtering. */
+      if (event->xfocus.mode == NotifyGrab ||
+          event->xfocus.mode == NotifyUngrab)
+        return;
       x_focus_changed (event->type,
                       (event->xfocus.detail == NotifyPointer ?
                        FOCUS_IMPLICIT : FOCUS_EXPLICIT),