bug#28850: 26.0.90; Error running timer 'jit-lock-stealth-fontify': (error "Invalid search bound (wrong side of point)")

[Eli Zaretskii]

> Date: Sun, 5 May 2019 09:06:22 +0000
> Cc: contovob@tcd.ie, 28850@debbugs.gnu.org
> From: Alan Mackenzie <acm@muc.de>
> 
> That's the theory.  The fix, which is now obvious, is to (setq
> before-sws-pos ...) after moving back over a macro.  Perhaps I should
> check the result of c-down-list-backward too, but that's to be done
> after checking the current fix.
> 
> I can't actually test this myself, so would you please try out the patch
> below in your test setup, and let me know whether it fixes this nasty
> bug.

With this patch, the problem is gone, so I guess you hit the nail on
the head.  Thanks.

(In terms of testing, I think you can visit textprop.c, then turn on
jit-lock-stealth, and let Emacs run for a while.  Without the patch,
you should see the error message pretty soon.)