bug#29150: Fwd: 26.0.90; Input decoding is sometimes skipped in TTY (xterm-mouse-mode)

[Eli Zaretskii <eliz@gnu.org>]

> From: Alex <agrambot@gmail.com>
> Cc: olaf.rogalsky@t-online.de,  29150@debbugs.gnu.org
> Date: Sun, 12 Nov 2017 18:00:57 -0600
> 
> >> Perhaps the patch should be replaced on the master branch with one that
> >> uses `read-key' in all cases?
> >
> > Why the rush?
> 
> I don't mean to rush anything, but I figured that I should mention it
> before I forget about it.

The thing is, I'm not yet sure read-key is TRT in this case.  We have
a lousy record in our changes of input processing code: almost every
change caused subtle bugs that took many moons to find and fix.  I
think we should recognize this vulnerability and behave more
cautiously.

> > If you want this on the release branch, it should be affect only
> > xt-mouse.  If you propose this for master, see above.
> 
> Do you mean that I shouldn't rush the `read-key' change for
> `mouse-drag-secondary' in master, either?

I'd like first to see how it fares on the release branch (and on
master), when it is limited to xt-mouse.

> Would applying the previous diff for master and the following for
> emacs-26 be acceptable?

Looks OK for the release branch (from which it will be merged to
master).  I'd prefer to wait with a more radical change even on
master.  Maybe put a FIXME comment there, to the effect that we should
try removing the condition at some point.

Thanks.