Subject: Re: bug#64658: 30.0.50; NotifyGrab and NotifyUngrab should be filtered with XInput2

From: Zigit Zo <[email-masked]>
Date: Sun, 16 Jul 2023 17:49:39 +0800

They're both 0, so the ~mode~ member is chosen :( For convenient, posted
all members when FocusIn event triggered, the last one is the cause of
~selected-frame~ changes.

#+begin_src
Thread 1 "emacs" hit Breakpoint 5, xi_handle_focus_change (dpyinfo=0x558ec6140c00) at ../../src/xterm.c:13068
13068	{
#2  0x0000558ec403e631 in event_handler_gdk (gxev=0x7ffd3ebb6080, ev=<optimized out>, data=<optimized out>)
     at ../../src/xterm.c:17671
$282 = (struct frame *) 0x558ec5dd5da0
"emacs - FRAME 1 TITLE"
(gdb) p *(XIFocusInEvent*) ((XEvent*) gxev)->xcookie.data
$284 = {
   type = 35,
   serial = 265494,
   send_event = 0,
   display = 0x558ec5ecb250,
   extension = 131,
   evtype = 9,
   time = 170569789,
   deviceid = 3,
   sourceid = 3,
   detail = 3,
   root = 483,
   event = 79691928,
   child = 0,
   root_x = 2769,
   root_y = 993,
   event_x = 2751,
   event_y = 879,
   mode = 3,
   focus = 0,
   same_screen = 1,
   buttons = {
     mask_len = 4,
     mask = 0x558ec9481958 ""
   },
   mods = {
     base = 64,
     latched = 0,
     locked = 0,
     effective = 64
   },
   group = {
     base = 0,
     latched = 0,
     locked = 0,
     effective = 0
   }
}

Thread 1 "emacs" hit Breakpoint 5, xi_handle_focus_change (dpyinfo=0x558ec6140c00) at ../../src/xterm.c:13068
13068	{
#2  0x0000558ec403e631 in event_handler_gdk (gxev=0x7ffd3ebb6080, ev=<optimized out>, data=<optimized out>)
     at ../../src/xterm.c:17671
$289 = (struct frame *) 0x558ec5dd5da0
"emacs - FRAME 1 TITLE"
(gdb) p *(XIFocusInEvent*) ((XEvent*) gxev)->xcookie.data
$291 = {
   type = 35,
   serial = 270527,
   send_event = 0,
   display = 0x558ec5ecb250,
   extension = 131,
   evtype = 9,
   time = 170569915,
   deviceid = 3,
   sourceid = 3,
   detail = 0,
   root = 483,
   event = 79691928,
   child = 0,
   root_x = 2769,
   root_y = 993,
   event_x = 2751,
   event_y = 879,
   mode = 2,
   focus = 0,
   same_screen = 1,
   buttons = {
     mask_len = 4,
     mask = 0x558ecc272658 ""
   },
   mods = {
     base = 64,
     latched = 0,
     locked = 0,
     effective = 64
   },
   group = {
     base = 0,
     latched = 0,
     locked = 0,
     effective = 0
   }
}

Thread 1 "emacs" hit Breakpoint 5, xi_handle_focus_change (dpyinfo=0x558ec6140c00) at ../../src/xterm.c:13068
13068	{
#2  0x0000558ec403e631 in event_handler_gdk (gxev=0x7ffd3ebb6080, ev=<optimized out>, data=<optimized out>)
     at ../../src/xterm.c:17671
$295 = (struct frame *) 0x558ecde5baf0
"emacs - FRAME 2 TITLE UNFOCUSED"
(gdb) p *(XIFocusInEvent*) ((XEvent*) gxev)->xcookie.data
$297 = {
   type = 35,
   serial = 270527,
   send_event = 0,
   display = 0x558ec5ecb250,
   extension = 131,
   evtype = 9,
   time = 170570127,
   deviceid = 3,
   sourceid = 3,
   detail = 5,
   root = 483,
   event = 79692372,
   child = 0,
   root_x = 2769,
   root_y = 993,
   event_x = 459,
   event_y = 879,
   mode = 1,
   focus = 0,
   same_screen = 1,
   buttons = {
     mask_len = 4,
     mask = 0x558ecb779b88 ""
   },
   mods = {
     base = 64,
     latched = 0,
     locked = 0,
     effective = 64
   },
   group = {
     base = 0,
     latched = 0,
     locked = 0,
     effective = 0
   }
}
#+end_sr

Hope this will be useful.

在 2023/7/16 17:09, Po Lu 写道:

> 左 智杰 <[email-masked]> writes:
>
>> In i3wm + xfce4 setup, when multiple frames opened, switch between frames
>> using only keyboard, and leave the mouse as:
>>
>> +-----------------+  +-----------------+
>> |                 |  |                 |
>> |                 |  |                 |
>> |                 |  |                 |
>> |                 |  |                 |
>> |                 |  |                 |
>> |                 |  |                 |
>> |     FRAME 1     |  |     FRAME 2     |
>> |    *FOCUSED*    |  |   *UNFOCUSED*   |
>> |                 |  |          ^      |
>> |                 |  |          |      |
>> |                 |  |        MOUSE    |
>> |                 |  |         HERE    |
>> |                 |  |                 |
>> +-----------------+  +-----------------+
>>
>> This will make the ~emacsclient -e '(selected-frame)'~ returns wrong frame, due to
>> XInput2 sends a ~NotifyGrab~ with the unfocused frame, making Emacs selects it.
>>
>> We've make a small but ugly changes to fix this issue:
>>
>> #+begin_src
>> diff --git a/src/xterm.c b/src/xterm.c
>> index 9ecead03b0..d4836afeeb 100644
>> --- a/src/xterm.c
>> +++ b/src/xterm.c
>> @@ -13193,6 +13193,11 @@ xi_focus_handle_for_device (struct x_display_info *dpyinfo,
>>     if (!device)
>>       return;
>>   
>> +  /* Same as x_detect_focus_change, issue persists in XInput2. */
>> +  if (event->evtype == XI_FocusIn || event->evtype == XI_FocusOut)
>> +    if (event->mode == XINotifyGrab || event->mode == XINotifyUngrab)
>> +      return;
>> +
>>     switch (event->evtype)
>>       {
>>       case XI_FocusIn:
>> #+end_src
>>
>> Wonder if we're correct?
> I don't want this hack in the input extension code, because it is much
> more sensitive to inconsistencies in the keyboard focus state.
>
> What is the value of event->send_event for these unwanted focus events?