Re: [9front] [PATCH] Fix shift release events in X11 drawterm with shift:both_capslock xmodmap option

["Timothy Robert Bednarzyk" <mail@trbsw.dev>]

> what exactly are you receiving from x11 when you "enable" your
> double-shift-caps-lock?
>
> 1. shiftdown_left 2. shiftdown_right 3. capslockdown 4. shiftup_left
> 5. shiftup_right 6. capslocksup ?
> which of these are visible, or are they in a different order? e.g. i
> can easily imagine something like 123645

Below, to the left of each colon represents what I am physically doing
and to the right represents the events that occur in X11. On the left, I
will use PL/PR for me pressing the left/right shift keys and RL/RR for
releasing the left/right shift keys. On the right, I will use your
numbers.

PL, RL: 1, 6.

PR, RR: 2, 6.

PL, PR, RL, RR: 1, 3, 6, 5.

PL, PR, RR, RL: 1, 3, 6, 6.

PR, PL, RL, RR: 2, 3, 6, 6.

PR, PL, RR, RL: 2, 3, 6, 4.

Interestingly, if I press one shift key, then the other, release the
first shift key, and then release the second one, I do actually get the
release event for the second shift key. I also don't get a press event
for that second shift key, but that makes sense to me since pressing the
second shift key is supposed to be interpreted as pressing caps lock
anyways. Perhaps most interesting to me though is that if I instead
release the second shift key before the first one I get two events for
releasing the caps lock in a row and zero events for releasing shift
keys.

While the press/release events work strangely with xmodmap's
shift:both_capslock option, the modifier masks do behave normally and I
believe that is why I have never noticed a problem in any other program
in the ~2/3 of a year that I've been using it (and why I wasn't stuck
typing in all caps through drawterm despite the mouse buttons staying
swapped). Perhaps a more robust solution to the problem would be to
probe the current state of the modifiers when handling things such as
mouse button presses rather than to rely on press/release events, but I
don't know nearly enough to know how difficult or feasible doing that
would be.

--
trb