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

[Alan Mackenzie]

Hello, Eli.

On Sun, Oct 15, 2017 at 19:07:50 +0300, Eli Zaretskii wrote:
> This bug is bugging me for quite some time now, and my hopes for it to
> be resolved are now gone, so I finally sat down to debug it.

> I have jit-lock-stealth turned on in my sessions, so whenever I
> restart Emacs (e.g., when I build a new binary, or after a system
> restart), and restore my session using desktop.el, Emacs starts
> fontifying in the background.  At some point, sometimes more than
> once, I get this error:

>   Error running timer 'jit-lock-stealth-fontify': (error "Invalid search 
> bound (wrong side of point)")

> Today I ran Emacs under a debugger, and caught this error.  The
> details are below, but in a nutshell, CC mode's fontification
> functions call re-search-forward with BOUND that is before point.  I
> hope the data below is enough to understand why that happens and fix
> it; if not, please tell what additional data is needed to diagnose the
> problem.

> Here're the C and Lisp backtraces from the error, and some relevant
> data that explains why the error happened:

Thanks for the bug report, and what you've worked out, so far.  I'm
afraid it's going to be several days before I get a chance to look at it
properly, with things in Real Life interfering significantly at the
moment.  I will look at it, though.

[ .... ]

-- 
Alan Mackenzie (Nuremberg, Germany).