bug#12936: 24.2; Setting 'jit-lock-defer-time' to number prevent some new buffers from automatic fontification.

bug#12936: 24.2; Setting 'jit-lock-defer-time' to number prevent some new buffers from automatic fontification.

[Oleksandr Gavenko]

I write to my .emacs:

  ;; Increase scrolling speed by defer consuming operation.
  (setq jit-lock-defer-time 0.01)

If I visit some file or create buffer - fontification does not performed until
I press any key.

For example: "M-x compile make RET" and *compilation* buffer fontified only if
I press some key after RET. Same with "M-x grep RET" and in another cases.

I can't find case when this happen in current buffer (only in buffer in other
window).

In GNU Emacs 24.2.1 (x86_64-pc-linux-gnu, GTK+ Version 2.24.10)
 of 2012-09-09 on trouble, modified by Debian

-- 
Best regards!

bug#12936: 24.2; Setting 'jit-lock-defer-time' to number prevent some new buffers from automatic fontification.

[Stefan Monnier]

> For example: "M-x compile make RET" and *compilation* buffer fontified
> only if I press some key after RET. Same with "M-x grep RET" and in
> another cases.
> I can't find case when this happen in current buffer (only in buffer
> in other window).

I'd guess it also misbehaves if you use `g' in the compile buffer (in
which case the output is placed in the current-buffer), because IIUC the
problem is that idle-timers (such as used by jit-lock-defer) are not
restarted after running process-filters.

While we should fix this bug, we should also fix the performance problem
that caused you to set jit-lock-defer-time (so please, report this
problem via M-x report-emacs-bug).


        Stefan

bug#12936: 24.2; Setting 'jit-lock-defer-time' to number prevent some new buffers from automatic fontification.

[Lars Ingebrigtsen]

Oleksandr Gavenko <gavenkoa@gmail.com> writes:

> I write to my .emacs:
>
>   ;; Increase scrolling speed by defer consuming operation.
>   (setq jit-lock-defer-time 0.01)
>
> If I visit some file or create buffer - fontification does not performed until
> I press any key.
>
> For example: "M-x compile make RET" and *compilation* buffer fontified only if
> I press some key after RET. Same with "M-x grep RET" and in another cases.

This was fixed as a special case in compile.el in 2014:
  
  ;; Turn off deferred fontifications in the compilation buffer, if
  ;; the user turned them on globally.  This is because idle timers
  ;; aren't re-run after receiving input from a subprocess, so the
  ;; buffer is left unfontified after the compilation exits, until
  ;; some other input event happens.
  (set (make-local-variable 'jit-lock-defer-time) nil)

However, removing that does not remove all fontifying, but it seems to
happen only after the compilation process has ended.

So I'm not sure -- there seems to be a general problem here, but is it
something that should be fixed?  Or is it up to individual modes (like
compilation mode) to switch delayed fontification off?  There's probably
not a lot of these modes that fontify process output on-the-fly.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#12936: 24.2; Setting 'jit-lock-defer-time' to number prevent some new buffers from automatic fontification.

[Lars Ingebrigtsen]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> This was fixed as a special case in compile.el in 2014:

[...]

> So I'm not sure -- there seems to be a general problem here, but is it
> something that should be fixed?  Or is it up to individual modes (like
> compilation mode) to switch delayed fontification off?  There's probably
> not a lot of these modes that fontify process output on-the-fly.

I think it's up to the individual modes, so I'm closing this bug report.
If it happens in other modes, please open a bug report for that.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no