1026425 - whole line of text in a textarea sometimes disappears after selecting/deselecting (possibly w/ connection to spellcheck's red squiggly underline)

Status: NEW

(Core :: Layout: Form Controls, defect)

Description

[Vincent Lefevre]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:30.0) Gecko/20100101 Firefox/30.0 (Beta/Release)
Build ID: 20140605174243

Steps to reproduce:

Write text in a form, e.g. a comment on Bugzilla, then double-click on a word.


Actual results:

The last line of my comment disappeared (but not the ~~~ in red from spell checking).


Expected results:

Nothing should have disappeared.

This bug occurs from time to time and has occurred for several months at least (previously with Debian's Iceweasel 24, and now with Firefox 30). Here it was after a double-click, but it could be after some edition in the textarea. The line that disappears is not always the last one of the textarea.

I can't provide a screenshot as the screenshot itself makes the line reappear.

Comment 1

[Daniel Holbert [:dholbert]]

I can reproduce this with this STR:
 (0) Visit https://bugzilla.mozilla.org/enter_bug.cgi?product=Core or any b.m.o bug page.
 (1) Type the following two lines into the bugzilla comment field ("====" excluded) (trailing space doesn't seem to matter):
====
baz
test
====
 (1a) Make sure that the first line ("baz") has a red squiggly underline. If it doesn't, type different text there that is obviously-misspelled & has an underline.
 (2) Double-click anywhere in the first line to highlight it.
 (3) Click somewhere to the right of the second line, to cancel the selection.

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: screencast

Here's a screencast of this bug in a fresh profile with today's nightly.
33.0a1 (2014-06-23)
Mozilla/5.0 (X11; Linux x86_64; rv:33.0) Gecko/20100101 Firefox/33.0

(I can't reproduce 100% of the time, unfortunately, but this is one of the times that I did reproduce.)

Comment 3

[Vincent Lefevre]

I can sometimes reproduce the bug in the comment field of a b.m.o bug page, but could never reproduce it with spell checking disabled (or when all words are recognized). So, indeed, it appears to be a consequence of the red squiggly underline.

Comment 4

[Holger]

Does the text reappear if you move the mouse out of the text-area and reenter it (no clicking)?

My old laptop (running Kubuntu) had some problems apparently using the outclassed 3D graphics to accelerate redraws. It only surfaced in text-areas within Firefox. Sometimes larger chunks of previously entered text would show up (e.g. still containing spelling errors I've corrected or parts of sentences I just deleted). Sometimes moved half a line up/down.

To me it looked like Firefox reused some off-screen buffer to repaint certain regions. But it did not clear them and just copied them to the screen without repainting them.

Comment 5

[Daniel Holbert [:dholbert]]

(In reply to Holger from comment #4)
> My old laptop (running Kubuntu) had some problems apparently using the
> outclassed 3D graphics to accelerate redraws. It only surfaced in text-areas
> within Firefox. Sometimes larger chunks of previously entered text would
> show up (e.g. still containing spelling errors I've corrected or parts of
> sentences I just deleted). Sometimes moved half a line up/down.

I've seen that as well, though I'm not able to reproduce any aspect of this bug right now.

I'm currently on my laptop, whereas comment 1 was on my desktop at the office. The machine I reproduced it on is using nouveau graphics drivers, which could conceivably be involved here.  Do other folks here know if they're using nouveau (the open-source driver for NVIDIA cards) or not?

Comment 6

[Vincent Lefevre]

(In reply to Holger from comment #4)
> Does the text reappear if you move the mouse out of the text-area and
> reenter it (no clicking)?

Sometimes (like just now), but not always.

Comment 7

[Vincent Lefevre]

(In reply to Daniel Holbert [:dholbert] from comment #5)
> I'm currently on my laptop, whereas comment 1 was on my desktop at the
> office.

The bug also occurs with my laptop. I don't think this matters. The NVIDIA cards on my laptop and desktop machines are similar.

> The machine I reproduced it on is using nouveau graphics drivers,
> which could conceivably be involved here.  Do other folks here know if
> they're using nouveau (the open-source driver for NVIDIA cards) or not?

I use nouveau, which is known to have such kind of problems. However the problem is new in Firefox, i.e. it never occurred some time ago even with the "nouveau" driver.

Comment 8

[Daniel Holbert [:dholbert]]

(In reply to Vincent Lefevre from comment #7)
> (In reply to Daniel Holbert [:dholbert] from comment #5)
> > I'm currently on my laptop, whereas comment 1 was on my desktop at the
> > office.
> 
> The bug also occurs with my laptop. I don't think this matters.

(Sure -- I wasn't suggesting this was "desktop-only"; I was commenting for my own reference, & for later sleuthing about what differentiates affected machines vs. non-affected machines. [e.g. "What graphics card does that unaffected-laptop have", etc.])

> I use nouveau, which is known to have such kind of problems. However the
> problem is new in Firefox, i.e. it never occurred some time ago even with
> the "nouveau" driver.

Ah! So this could indeed be a nouveau bug (which Firefox only recently-ish started triggering, due to more aggressive use of 3D acceleration).

Comment 9

[Holger]

(In reply to Vincent Lefevre from comment #6)
> (In reply to Holger from comment #4)
> > Does the text reappear if you move the mouse out of the text-area and
> > reenter it (no clicking)?
> 
> Sometimes (like just now), but not always.

"My" Bug was different, it would resolve drawing problems every single time. I frequently and reliably used this workaround to finish typing longer texts.

The old machine had an ATI Radeon onboard graphics running the open source radeon driver.

This new Laptop does not suffer from this bug, neither the Nvidia geforce with Nvidia binary driver nor the Intel onboard graphics as fallback. But I might come back, once Nvidia drops support for my model and I have to switch to the opensource drivers ... hopefully not!

Comment 10

[Vincent Lefevre]

(In reply to Vincent Lefevre from comment #6)
> (In reply to Holger from comment #4)
> > Does the text reappear if you move the mouse out of the text-area and
> > reenter it (no clicking)?
> 
> Sometimes (like just now), but not always.

Well, it seems that I actually need to move the mouse out of the Firefox window (this works on mozilla.org), which loses focus since I use FocusFollowsMouse. I don't remember exactly because it appears that several redraw bugs interfere, such as bug 1026773.

For the reference, the nouveau redraw bugs affecting my machines:

  https://bugs.freedesktop.org/show_bug.cgi?id=49786
  https://bugs.freedesktop.org/show_bug.cgi?id=72979

I've been using compton for several months as a workaround to the former bug, so that it is not in cause here with Firefox (and the problem was a bit different since it was a forgotten redraw instead of an incorrect redraw). The latter one might be related.

Comment 11

[Vincent Lefevre]

(In reply to Vincent Lefevre from comment #10)
> (In reply to Vincent Lefevre from comment #6)
> > (In reply to Holger from comment #4)
> > > Does the text reappear if you move the mouse out of the text-area and
> > > reenter it (no clicking)?
> > 
> > Sometimes (like just now), but not always.
> 
> Well, it seems that I actually need to move the mouse out of the Firefox
> window (this works on mozilla.org), which loses focus since I use
> FocusFollowsMouse.

On StackExchange, this doesn't work. However there, the line doesn't only disappear, but it is also replaced with an incorrect background (my default background browser.display.background_color is not white). But this very similar problem may actually be bug 1026773.

Comment 12

[yaztromo]

This is not a bug in Firefox. It is a bug in the open source Radeon drivers. I have seen it with many different Radeon cards only when using the open source driver.

If you have this issue and are using an nvidia card then that is a separate bug I think.

If you have a card that is supported by the proprietry Radeon drivers then you can install those to fix the issue.

A quick fix for the text area corruption is to zoom by pressing ctrl-+ and zoom back with ctrl--.

Comment 13

[Daniel Holbert [:dholbert]]

(In reply to yaztromo from comment #12)
> This is not a bug in Firefox. It is a bug in the open source Radeon drivers.
[...]
> If you have this issue and are using an nvidia card then that is a separate
> bug I think.

To be fair, the original reporter (Vincent) was using a NVIDIA card, per comment 7. :) So if you're sure that there are separate NVIDIA vs. Radeon bugs here, then it's really the radeon issue that deserves a separate bug. (In both cases it seems to boil down to bugs in open-source video drivers, regardless, though.)

Comment 14

[Holger]

Sorry, I didn't mean to take over this bug. I just stumbled on it and the screencast really looked like my old problem (text reappears on moving mouse out), so I thought, I share in case it helps by casting another view on the problem. Actually the ATI-radeon part solved itself for me, the moment I ditched the old computer.