Re: Default of jit-lock-stealth-time

[David Kastrup <dak@gnu.org>]

Richard Stallman <rms@gnu.org> writes:

>     So yes, there is likely a bug (or whatever one may call something that
>     takes up too much time) in this particularly severe case, but it is
>     not triggered outside of stealth fontification, and stealth
>     fontification makes the problem be pretty much impossible to debug
>     properly, and triggers it when editing _any_ buffer.
>
> Is the bug in font-latex, perhaps?

I think it imprudent to call it "the bug": any problem in font
highlighting patterns in any of the loaded buffers/major modes can
have the same, non-traceable effects.  I already said that I have seen
similar things with cc-mode.  Until we can guarantee that all major
modes have efficient font lock patterns/code ("correct" alone does not
cut it), stealth fontification will hide problems while making them
more severe.

After some back and forth with one AUCTeX developer, I have asked him
to install a private branch to font-latex which is likely related to
the problem seen with texbook.tex.  It would be my guess that it might
address the particular performance problem seen with texbook.tex.

So the problem triggered by this particular input file might be gone
with future releases of AUCTeX.

But as I already stated: this was merely the file that broke the
camel's back for me and caused me to report the problem which I was
unable to trace to a cause (stealth fontification _is_ stealthy in
hiding its tracks, if not its effects).

And it certainly was not the file that caused several other developers
to disable stealth fontification before (which they then reported).

-- 
David Kastrup