bug#24109: 24.5; Long lines in message mode make Emacs irresponsive

[Eli Zaretskii]

> From: Yuri D'Elia <wavexx@thregr.org>
> Cc: 24109@debbugs.gnu.org, djcb@djcbsoftware.nl, 
> Christophe.Troestler@umons.ac.be, rudalics@gmx.at
> Date: Wed, 31 Aug 2016 18:49:30 +0200
> 
> > For starters, in this line:
> >
> >             if (w->hscroll != hscroll)
> >
> > what are the values of those two, and do they change each time
> > hscroll_windows is called in the infloop, for the selected window?
> 
> They swap the value at each iteration:
> 
> Thread 1 "emacs" hit Breakpoint 14, hscroll_window_tree (window=20142453) at 
> xdisp.c:13086
> $154 = 0
> $155 = 487
> Continuing.
> 
> Thread 1 "emacs" hit Breakpoint 14, hscroll_window_tree (window=20142453) at 
> xdisp.c:13086
> $156 = 487
> $157 = 0
> Continuing.

What are your values of hscroll-step and hscroll-margin?