bug#16347: 24.3.50; Company pseudo-tooltip refresh problem when expanded down at eob

bug#16347: 24.3.50; Company pseudo-tooltip refresh problem when expanded down at eob

[Dmitry Gutov]

`company-select-next' (`M-n') and `company-select-previous' (`M-p')
don't update the default candidates' dropdown appearance, specifically
the "current" line selection doesn't move.

It's easiest to spot in a new IELM session.

1. M-x ielm.
2. Make sure that there's no text after point, and there are enough
screen lines below it so that the pseudo-tooltip will be rendered below
the current line.
3. M-x company-complete.
4. Press `M-n' and/or `M-p' several times. Note that the "current"
candidate doesn't change, but different summary lines get shown in the
echo area.

In some other buffers, the "current" lines can move 1-2 times, but then
it likewise stops getting updated.

It's a relatively recent problem. I haven't had time to bisect it yet,
but Emacs 24.3 definitely doesn't have this bug.


In GNU Emacs 24.3.50.4 (x86_64-unknown-linux-gnu, GTK+ Version 3.8.6)
 of 2014-01-04 on axl
Bzr revision: 115859 vincentb1@users.sourceforge.net-20140103141824-juu968y9pi6r2zvv
Windowing system distributor `The X.Org Foundation', version 11.0.11403000
System Description:	Ubuntu 13.10

bug#16347: Acknowledgement (24.3.50; Company pseudo-tooltip refresh problem when expanded down at eob)

[Dmitry Gutov]

'bzr bisect' points to

revision 115272 (monnier@iro.umontreal.ca-20131128224309-jg2ar5frhpri4yow):
Refine redisplay optimizations to only redisplay *some* frames/windows
rather than all of them.

Stefan, any ideas?

Please let me know if you have problems reproducing this.

The original recipe won't work if company-mode is not enabled is the 
current buffer. So prepend 3. with `M-x company-mode'.

bug#16347: 24.3.50; Company pseudo-tooltip refresh problem when expanded down at eob

[Stefan Monnier]

> 1. M-x ielm.
> 2. Make sure that there's no text after point, and there are enough
> screen lines below it so that the pseudo-tooltip will be rendered below
> the current line.
> 3. M-x company-complete.
> 4. Press `M-n' and/or `M-p' several times. Note that the "current"
> candidate doesn't change, but different summary lines get shown in the
> echo area.

I can't reproduce it.  Here's what I did:

  src/emacs -Q -l ../elpa/packages/company/company-autoloads.el -f ielm -f company-mode
  M-x company-complete RET
  M-n M-n M-n ... M-p M-p ...

and I didn't notice anything strange happening: every M-n or M-p
correctly moved the higlighting in the popup menu to the next/previous line.


        Stefan

bug#16347: 24.3.50; Company pseudo-tooltip refresh problem when expanded down at eob

[Eli Zaretskii]

> Date: Wed, 08 Jan 2014 10:49:40 +0400
> From: Dmitry Gutov <dgutov@yandex.ru>
> Cc: 16347@debbugs.gnu.org
> 
> 'bzr bisect' points to
> 
> revision 115272 (monnier@iro.umontreal.ca-20131128224309-jg2ar5frhpri4yow):
> Refine redisplay optimizations to only redisplay *some* frames/windows
> rather than all of them.
> 
> Stefan, any ideas?
> 
> Please let me know if you have problems reproducing this.

I'm not Stefan, but I have problems reproducing this.  Is the recipe
complete enough to start with "emacs -Q"?  Obviously, there should be
a step to add the company directory to load-path, but are there any
other customizations that are necessary?

Also, the description of the problem is not entirely clear to me.  By
"current candidate" do you mean the completion candidate whose line in
the pseudo-tooltip is displayed with a distinct color?  If so, I never
saw that line not update in response to M-n/M-p.  You also talk about
"summary lines shown in the echo area", but if I follow your recipe, I
see nothing in the echo area, and the *Messages* buffer confirms that
nothing was displayed there.

Finally, did you try with the current trunk?  Your original report is
about a revision after which a fix for a similar redisplay problems
was committed, so is there any chance you are still using an outdated
trunk code?

bug#16347: 24.3.50; Company pseudo-tooltip refresh problem when expanded down at eob

[Dmitry Gutov]

Sorry, you both. Here's the missing piece:

(setq bidi-display-reordering nil)

This is pretty low-level var, so maybe it's not even supposed to be set 
by a user.

On 08.01.2014 21:55, Eli Zaretskii wrote:
> I'm not Stefan, but I have problems reproducing this.  Is the recipe
> complete enough to start with "emacs -Q"?  Obviously, there should be
> a step to add the company directory to load-path, but are there any
> other customizations that are necessary?

Sorry, see above.

> Also, the description of the problem is not entirely clear to me.  By
> "current candidate" do you mean the completion candidate whose line in
> the pseudo-tooltip is displayed with a distinct color?

Yes.

> You also talk about
> "summary lines shown in the echo area", but if I follow your recipe, I
> see nothing in the echo area, and the *Messages* buffer confirms that
> nothing was displayed there.

Indeed, this only happens when a suitable backend gets enabled, and 
company-elisp only works in IELM buffers in the upstream Company, not 
yet with code in ELPA. You can try

(require 'company-capf)
M-x company-capf

but that really doesn't matter, since it's unrelated to the bug and just 
indicates that the current candidate has indeed changed after you 
pressed M-n or M-p, and it's just overlay display that wasn't updated.

> Finally, did you try with the current trunk?  Your original report is
> about a revision after which a fix for a similar redisplay problems
> was committed, so is there any chance you are still using an outdated
> trunk code?

I saw that fix, but no change.

bug#16347: 24.3.50; Company pseudo-tooltip refresh problem when expanded down at eob

[Eli Zaretskii]

> Date: Thu, 09 Jan 2014 17:23:02 +0400
> From: Dmitry Gutov <dgutov@yandex.ru>
> CC: monnier@IRO.UMontreal.CA, 16347@debbugs.gnu.org
> 
> Sorry, you both. Here's the missing piece:
> 
> (setq bidi-display-reordering nil)

OK, now I see the problem.

> This is pretty low-level var, so maybe it's not even supposed to be set 
> by a user.

Indeed, it isn't.  But in this case, all it does is enable a redisplay
optimization that is disabled when bidi-display-reordering is non-nil.
So there's a bug either in that redisplay optimization or in the
conditions that enable it (probably the latter).

I will take a look.

bug#16347: 24.3.50; Company pseudo-tooltip refresh problem when expanded down at eob

[Eli Zaretskii]

> Date: Thu, 09 Jan 2014 18:44:28 +0200
> From: Eli Zaretskii <eliz@gnu.org>
> Cc: 16347@debbugs.gnu.org
> 
> > Date: Thu, 09 Jan 2014 17:23:02 +0400
> > From: Dmitry Gutov <dgutov@yandex.ru>
> > CC: monnier@IRO.UMontreal.CA, 16347@debbugs.gnu.org
> > 
> > Sorry, you both. Here's the missing piece:
> > 
> > (setq bidi-display-reordering nil)
> 
> OK, now I see the problem.
> 
> > This is pretty low-level var, so maybe it's not even supposed to be set 
> > by a user.
> 
> Indeed, it isn't.  But in this case, all it does is enable a redisplay
> optimization that is disabled when bidi-display-reordering is non-nil.
> So there's a bug either in that redisplay optimization or in the
> conditions that enable it (probably the latter).
> 
> I will take a look.

Fixed in trunk revision 115974.

bug#16347: 24.3.50; Company pseudo-tooltip refresh problem when expanded down at eob

[Dmitry Gutov]

On 11.01.2014 15:55, Eli Zaretskii wrote:
> Fixed in trunk revision 115974.

Thank you.