bug#48042: 26.3; Macros don't work with french-postfix input method

[Eli Zaretskii <eliz@gnu.org>]

> Date: Sat, 15 May 2021 18:47:00 +0000
> From: Gregory Heytings <gregory@heytings.org>
> cc: monnier@iro.umontreal.ca, harven@free.fr, 48042@debbugs.gnu.org
> 
> > To tell you the truth, I'm a bit worried that you inhibit recording 
> > everywhere in quail.el, which seems to contradict my analysis from back 
> > when I made the inhibit--record-char.  How many different input methods 
> > did you try with macros and "C-h l" to make sure this change indeed 
> > causes Emacs to record each produced character just once, and nothing is 
> > either omitted or recorded more than once?  Did you try some CJK input 
> > methods, for example, which offer several alternatives for each key 
> > sequence the user typed?
> 
> I tried french-postfix, russian-computer, ucs, TeX, arabic, japanese and 
> chinese-py.  From what I can see, everything works as expected, but I 
> don't speak or read these languages, and there are more than 200 input 
> methods, I cannot test them all.

No one can test all of them, that's not what I meant.

> > Btw, what happens if while this code runs, the user types something? We 
> > don't want those events to be cleared.
> >
> 
> It's quite hard to type something at that moment AFAICS, the whole 
> terminal initialization typically takes at most 50 ms.  I tried to type 
> something as fast as possible during the terminal initialization, and what 
> happens is this (visible in *Messages*):
> 
> q is undefined
> M-] is undefined
> ; is undefined
> r is undefined
> g is undefined
> b is undefined
> : is undefined
> f is undefined [4 times]
> / is undefined
> f is undefined [4 times]
> / is undefined
> f is undefined [4 times]
> 
> or this:
> 
> q is undefined
> M-[ > is undefined
> ; is undefined [2 times]
> c is undefined
> 
> The first key is the pressed key ("q"), the other keys are some of the 
> keys of the terminal initialization process (the digits are bound to 
> digit-argument in the *GNU Emacs* buffer and are therefore not undefined):
> 
> ESC [ > ESC [ > 4 1 ; 3 6 6 ; 0 c ESC ] 1 1 ; r g b : f f f f / f f f f / 
> f f f f ESC \
> 
> IOW, if the user presses something at that moment, the terminal 
> initialization process does not work as expected.

So maybe we shouldn't discard the input if the initialization fails?
Otherwise we leave no traces that could allow understanding what
happened.

Thanks.