bug#18649: 25.0.50; Closing TTY menus on MS-Windows

[Eli Zaretskii <eliz@gnu.org>]

> Date: Wed, 08 Oct 2014 15:35:31 +0200
> From: martin rudalics <rudalics@gmx.at>
> CC: 18649-done@debbugs.gnu.org
> 
>  >> BTW: Is there a way to turn `blink-cursor-mode' off on a TTY?
>  >
>  > No, it blinks "in hardware" (i.e., the terminal software does it).
>  > And there's no reason to disable it, because it should never do
>  > anything on a TTY.  Or do you have evidence to the contrary?
> 
> No.  I just wondered why the cursor disappeared (as Dani also observed)
> when doing C-g with an open menu.

Because the TTY menu code hides the cursor, and since C-g bypassed
that code, the part of it that restores the cursor after popping down
the menu didn't execute.  It has nothing to do with blink-cursor-mode.

> Ah, I seem to understand.  resize_frame_windows never gets called here
> because the size of the root window apparently doesn't change.  OTOH
> frame_windows_min_size gets called unconditionally.  So it's merely
> coincidental that this problem didn't hit us before.

Yes.  In general, calling change_frame_size from the input handler was
simply wrong.

> BTW, I call frame_windows_min_size unconditionally in order to detect
> the case where
> 
> (1) the frame size itself should be conceptually left unchanged, but
> 
> (2) something _within_ the frame changes (like adding a tool or scroll
>      bar) which requires a larger frame size to keep all windows of the
>      frame visible.
> 
> All this is unnecessary on TTYs.

Maybe, but who knows what happens with all the latest hot stuff, like
tmux etc.?