bug#21747: 25.0.50; while-no-input breaks kbd event handling when called from post-command-hook

[Eli Zaretskii <eliz@gnu.org>]

> From: Tassilo Horn <tsdh@gnu.org>
> Cc: bruce.connor.am@gmail.com,  monnier@iro.umontreal.ca,  storm@cua.dk,  21747@debbugs.gnu.org
> Date: Sat, 24 Oct 2015 14:13:54 +0200
> 
> Actually, the `post-command-hook' function in question
> (aggressive-indent--indent-if-changed) is not so overly expensive.  At
> least I have validated that it has finished running I type the next key,
> thus the abort-on-input case doesn't even occur.
> 
> My recipe for reproduction is
> 
>   1. emacs -Q
>   2. M-x package-initialize
>   3. M-x global-aggressive-indent-mode
>   4. C-x C-f ~/test.sh
>   5. type the keyword if where the i is displayed immediately
>      and the display of f is delayed
> 
> This does only occur for sh-mode keywords like if, while, etc. where the
> delaying starts with after entering the last char of the keyword.  Also,
> I can reproduce that problem only if test.sh doesn't exist.

I don't understand: are you saying that the post-command-hook finished
its job, and yet redisplay is not entered?

> Or well, I just tried what happens when I replace the `while-no-input'
> with a `progn'.  Then Emacs goes into some infloop.  Attaching with gdb
> shows:

There's a procedure in etc/DEBUG to determine which call-stack frame
infloops, please use it and tell what you found.

Thanks.