[Bug 53778] New: delete key doesn't works on bepo layout

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=53778

Bug ID: 53778
           Summary: delete key doesn't works on bepo layout
           Product: Wine
           Version: 7.18
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: winex11.drv
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 73263
  --> https://bugs.winehq.org/attachment.cgi?id=73263
Trace

On a bepo layout, pressing the delete key not only deletes the character under
the keyboard cursor, but also inserts a ".".

How to reproduce:

1. wine notepad

2. setxkbmap fr bepo (tip: type setxkbmap us in another terminal before
switching the layout so you just have to press enter to change back to an us
keyboard)

3. Type any string (for example "test"), place the keyboard cursor anywhere
inside the string (for example before "e"), press the delete key

4. Expected result: "tst". Actual result: "t.st"

Attached is a trace with WINEDEBUG=+msg in both scenarios (we see that in the
bepo case, a WM_CHAR event is sent which shouldn't happen). xev shows no
meaningful difference.

[Bug 53778] delete key doesn't works on bepo layout

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=53778

--- Comment #1 from [e-mail] ---
Found the issue.

To translate a WM_KEYDOWN / WM_KEYUP event (virtual key & scan code) to a
WM_CHAR event, the X11 driver loops over all keycodes, finds what virtual key
would generate that key code, and if there's a match, generate an X event to
look at the associated string
(https://gitlab.winehq.org/wine/wine/-/blob/master/dlls/winex11.drv/keyboard....).

But there’s actually two keycodes that can generate the VK_DELETE virtual key :
the one associated with the actual delete key, and the one associated with the
keypad delete. For us keyboards, it is actually correctly handled by translated
a KP_* keysym to the correct virtual key
(https://gitlab.winehq.org/wine/wine/-/blob/master/dlls/winex11.drv/keyboard....).

Unfortunately, as can be seen in xev, bepo keyboard gives a "." keysym for
keypad ".", not XK_KP_Separator, leading to the described incorrect behavior. A
cursory glance at /usr/share/X11/xkb quickly shows it’s a mess here, with the
keypad delete key can be associated with either ".", ",", XK_KP_Separator or
XK_KP_Decimal, depending on (if I understand it right) udev rules (?!)

Not sure how it can be fixed on Wine end, or if it SHOULD be fixed on Wine end.

Anyway, I solved it on my end by adding a kpdl(comma) option to the XKB
configuration, forcing it to send a XK_KP_Separator keysym.