Re: Emacs very slow opening file

[Stefan Monnier]

>> You can still see the same problem with the above if right after opening
>> the file you do M->

> Yes, I can. In fact if I leave y-or-n-p defined as it should be, I see the
> long pause twice - once when I visit the file and once again when I do
> "M->".  Is Emacs font-lockifying the buffer twice?

Looks that way.  This may be due to the new code that turns font-lock
OFF-then-ON in case the font-lock-keywords were changed in the mean time.

> So it's a conjunction of mostly 2 problems:
>> - accidental use of C mode.
>> - slowness of C font-lock-keywords on non-C text.
>> I'm not sure how to best avoid/fix the problem.
> Would it help to treat ".patch" files specially?

With a file name "bigfile" this wouldn't help, but if your file has a .patch
extension, yes of course that would help.

> I notice inhibit-first-line-modes-regexps is treating .tar and .tgz files
> specially, but possibly only for leading -*- lines. We know that .patch
> files are potentially going to contain file local variables which we
> shouldn't honour.

That sounds like a good approach.  But it seems that the variable indeed
only has an effect on the -*- on the first line, not for the "Local
Variables" section at the end.


        Stefan