Re: Emacs freezes again when I try to open a file including only one very long line.

[Eli Zaretskii <eliz@gnu.org>]

> From: Michael Heerdegen <michael_heerdegen@web.de>
> Date: Thu, 30 Jun 2022 14:52:54 +0200
> 
> Would it be more sensible to do something different than showing the
> partially redisplayed window with a non-blinking cursor?

I'd need more specific proposals to say anything intelligent.  To your
general question, my only answer is: this is what avoiding redisplay
of a window looks like in Emacs.  (Perhaps you didn't realize, but
blinking the cursor on a GUI frame requires a redisplay cycle each
time the cursor is turned on or off -- that's why it stops blinking in
the window whose buffer is marked "not for redisplay".)

> Even if Emacs successfully aborted redisplay and everything is good,
> people might think Emacs is still frozen because it looks
> frozen. That's what happened to me: I thought the feature wouldn't
> work with my config for some reason, until I tried to select a
> different window and then - ah! - that actually works!  But it took
> some time...

I think it's a one-time "eureka!" thing -- once you realize that this
is what happens, it will no longer be a surprise.  (Note that the
warning popping up was a last-minute improvement: the original
implementation just silently stopped updating the window, because we
cannot signal an error from redisplay in a way that causes an error
message to appear in the echo-area.)

Again, practical proposals for something you think is better are
welcome.