Re: Removing the `window-id' frame parameter on non-Core Input platforms

[Po Lu]

Eli Zaretskii <eliz@gnu.org> writes:

> But that isn't Emacs-specific, is it?  AFAIR, the window ID is a
> general X feature, we just support it.

Yes, but after working around the fullscreen freeze bug, we can no
longer longer guarantee that a frame's XID will remain constant (and
therefore useful).

>> Other uses of the `window-id' parameter such as to display windows as
>> children of a frame are discouraged on XInput2 builds, as it can
>> interfere with XInput2 event handling

> You mean, using it for our child frames?

No, other processes using it to place their windows onto our frames.

The problem is that XInput2 touch support was designed to assume that a
single client owns a window and all its children.  Introducing another
process and therefore client into the window hierarchy causes all kinds
of race conditions when two processes try to take ownership of the same
touch sequence at once, and so on and so forth.

Thanks.