1508378 - [Wayland]Text cursor leaves remnants when moved

Status: RESOLVED FIXED

(Core :: Widget: Gtk, defect, P3)

Description

[jcdawes92]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:65.0) Gecko/20100101 Firefox/65.0

Steps to reproduce:

Type into a text box, such as the one to log a bug here, then press the left cursor key a few times.  


Actual results:

This will leave a trail of vertical remnants of the text cursor as it moves.  Only seems to happen on left moves, not right


Expected results:

No remnants should be left behind

Comment 1

[Martin Stránský [:stransky] (ni? me)]

I do see that too but only on 4K display. I can't reproduce on lower resolutions. I suspect it's a bug in mutter/gnome, there's nothing Firefox can fix here.

Comment 2

[Martin Stránský [:stransky] (ni? me)]

This can be also caused by gfx card/driver, can you attach content of about:support page?

Comment 3

[jcdawes92]

Attachment: about:support

Comment 4

[jcdawes92]

Hi Martin,
I don't get this effect in anything else on Wayland, for example gedit which uses the same cursor.
Also I don't get the problem if I start Firefox on Xwayland, so it seems pretty specific.

Comment 5

[Martin Stránský [:stransky] (ni? me)]

(In reply to jcdawes92 from comment #4)

Hi Martin,
I don't get this effect in anything else on Wayland, for example gedit which
uses the same cursor.
Also I don't get the problem if I start Firefox on Xwayland, so it seems
pretty specific.

Yes, I can confirm that.

Comment 6

[Martin Stránský [:stransky] (ni? me)]

Can you please try to enable webrender/GL backend? Set layers.acceleration.force-enabled to true at about:config. Thanks.

Comment 7

[Martin Stránský [:stransky] (ni? me)]

Also do you use screen scaling/ HiDPI displays? I can reproduce only when I have 200% screen scale set.

Comment 8

[Martin Stránský [:stransky] (ni? me)]

I think I have a patch for it.

Comment 9

[Martin Stránský [:stransky] (ni? me)]

Attachment: Bug 1508378 - Fix round error when damage rect size/position is odd number and scale factor is used, r=lsalzman

We have rendering artifacts when sceen scale is set and damage size/position is odd number.
It's caused by round error so update the size/position accordingly.

Comment 10

[jcdawes92]

Hi Martin,
yes, I am using a HIDPI display with 200% scaling.
Turning on webrender/GL backend makes a small difference. There are fewer remnants and they clean themselves up after a few seconds or when something else is updated.
For example, while entering this text, if I hold down left-arrow I get loads of remnants for a few seconds, then it suddenly clears up.

Comment 11

[Martin Stránský [:stransky] (ni? me)]

(In reply to jcdawes92 from comment #10)

Hi Martin,
yes, I am using a HIDPI display with 200% scaling.
Turning on webrender/GL backend makes a small difference. There are fewer
remnants and they clean themselves up after a few seconds or when something
else is updated.
For example, while entering this text, if I hold down left-arrow I get
loads of remnants for a few seconds, then it suddenly clears up.

The webrender/GL artifacts may be a different bug. This should be fixed in the SW rendered with this patch at least.

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/38b3fac27d90
Fix round error when damage rect size/position is odd number and scale factor is used, r=lsalzman

Comment 13

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/38b3fac27d90