646053 - dark diagonals at corner joins adjacent to transparent borders

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect)

Description

[Kumar Harsh]

User-Agent:       Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0
Build Identifier: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0

On some machines, the code given in the URL field (http://jsfiddle.net/rv3DZ/4/) adds a gray border along the edge of the normal border.

Other browsers such as Google Chrome, Safari, and even IE8 render the code perfectly. Also, on some machines, this code is rendered perfectly even on Firefox, but not on others. 
Even a clean install of ff4.0 does not resolve the issue, nor does starting it in a safe mode.

Currently, this bug can be circumvented by using the -moz-border-*-colors attribute and setting its value to, say transparent (in the example).

Reproducible: Always

Steps to Reproduce:
1. Go to the URL specified to get an example code.
2. Click on update button to get the rendering.
Actual Results:  
A thin (1px) gray border surrounding the normal coloured border

Expected Results:  
There should be no gray border at all.

The bug occurs, even after disabling all the addons.
The bug occurs on some machines, but not on all the machines.

Comment 1

[Kumar Harsh]

Pls use this URL for getting the code in question :

http://jsfiddle.net/sigmabetatooth/rv3DZ/6/

Comment 2

[Stephen Williams]

I am also experiencing this in FF4 but not in ff3.6

Comment 3

[Stephen Williams]

http://jsfiddle.net/sigmabetatooth/rv3DZ/ ;)

Comment 4

[Alfredos-Panagiotis Damkalis [:fredy]]

This is happening to me too. I get gray border at the two edges of the first triangle.

Screenshot:
http://i.imgur.com/a7MiF.png

Comment 5

[Boris Zbarsky [:bzbarsky]]

Does turning off d2d or hardware acceleration help?

Comment 6

[Stephen Williams]

tobias: Please verify your OS and FF version

(In reply to comment #4)
> This is happening to me too. I get gray border at the two edges of the first
> triangle.
> 
> Screenshot:
> http://i.imgur.com/a7MiF.png

Comment 7

[Stephen Williams]

Boris: great question. how do you turn these off?

(In reply to comment #5)
> Does turning off d2d or hardware acceleration help?

Comment 8

[Alfredos-Panagiotis Damkalis [:fredy]]

ff4 amd64/ linux

also I don't know if it is relevant, I noticed that if test goes over 200px then the top of the triangle it creates an artifact which you can see at this screenshot: http://i.imgur.com/OOFsX.png

Comment 9

[Alfredos-Panagiotis Damkalis [:fredy]]

turning off hardware acceleration (from options/preferences->advanced) doesn't change anything.

Comment 10

[Boris Zbarsky [:bzbarsky]]

> Boris: great question. how do you turn these off?

Flip "gfx.direct2d.disabled" to "true" in about:config and restart to turn off direct2d.

tobias, did you restart after changing that preference?  It's not live last I checked.

Comment 11

[Kumar Harsh]

boris : the borders are still rendered... no change after disabling hardware acceleration...

Comment 12

[Matthias Versen [:Matti]]

The safemode already disabled the hardware acceleration
from comment#0 "nor does starting it in a safe mode."

Comment 13

[Alfredos-Panagiotis Damkalis [:fredy]]

(In reply to comment #10)
> > Boris: great question. how do you turn these off?
> 
> Flip "gfx.direct2d.disabled" to "true" in about:config and restart to turn off
> direct2d.
> 
> tobias, did you restart after changing that preference?  It's not live last I
> checked.

Yes i had restarted and I tried it just couple of minutes before to be sure. The option that changed at about:config was layers.acceleration.disabled when i disable hardware acceleration. About the gfx.direct2d.disabled, I don't have such an option, maybe because I use the stable 64bit linux release of ff4.

Comment 14

[Boris Zbarsky [:bzbarsky]]

Ah, ok.  If you're seeing this on both Windows and Linux (and I don't see it on Mac, fwiw), then it sounds like a bug in Cairo path stuff...  We have a bunch of those already.  :(

Comment 15

[Stephen Williams]

Boris: for future reference what is the "Cairo path stuff" you speak of and is there one particular bug example to look at?

(In reply to comment #14)
> Ah, ok.  If you're seeing this on both Windows and Linux (and I don't see it on
> Mac, fwiw), then it sounds like a bug in Cairo path stuff...  We have a bunch
> of those already.  :(

Comment 16

[Boris Zbarsky [:bzbarsky]]

The "cairo path stuff" is the path tesselator and rasterizer in cairo.  We use it on Windows and Linux; we use the CoreGraphics path functionality directly on Mac.

Comment 17

[Stephen Williams]

Kumar: would you be willing to update this to reflect the discoveries.

Only ocures in windows and linux. Potentially related to Cairo. etc.

Comment 18

[j.j.]

Attachment: testcase

Comment 20

[Oscar Godson]

Happening to me also in Win XP and 7 / FF4, but NOT Mac OS X:
http://jsbin.com/alame5 

Mac:
https://img.skitch.com/20110502-1j3b71c8w4s3c9m692kcxd4djf.jpg

Windows 7 (and XP):
https://img.skitch.com/20110502-j27inn3yq24te63baedpcgk5ys.jpg

Comment 21

[Bas Schouten (:bas.schouten)]

(In reply to comment #20)
> Happening to me also in Win XP and 7 / FF4, but NOT Mac OS X:
> http://jsbin.com/alame5 
> 
> Mac:
> https://img.skitch.com/20110502-1j3b71c8w4s3c9m692kcxd4djf.jpg
> 
> Windows 7 (and XP):
> https://img.skitch.com/20110502-j27inn3yq24te63baedpcgk5ys.jpg

This bug will likely occur in any environment where Cairo draws the Gradient, Windows GDI or Linux. But not on Windows with Direct2D or on Mac where we use Quartz.

Comment 22

[Kumar Harsh]

(In reply to comment #21)
> (In reply to comment #20)
> > Happening to me also in Win XP and 7 / FF4, but NOT Mac OS X:
> > http://jsbin.com/alame5 
> > 
> > Mac:
> > https://img.skitch.com/20110502-1j3b71c8w4s3c9m692kcxd4djf.jpg
> > 
> > Windows 7 (and XP):
> > https://img.skitch.com/20110502-j27inn3yq24te63baedpcgk5ys.jpg
> 
> This bug will likely occur in any environment where Cairo draws the Gradient,
> Windows GDI or Linux. But not on Windows with Direct2D or on Mac where we use
> Quartz.

Can we use Direct2D instead of Cairo ??? (just asking)

Comment 25

[Paul Eustice]

I also noticed that the bug only applies to 'solid' border style. Dotted, dashed, ridge, double etc all seem to display correctly.

As a workaround for anyone that is interested in using it before the bug is fixed, you can replace your transparent borders with rgba(255,255,255,0).

e.g. border: 6px solid rgba(255,255,255,0.0);

Seems to work fine for me on FF6, Windows XP.

Comment 26

[j.j.]

Confirming that workaround rgba(255,255,255,0) works, thanks!

Comment 27

[Boris Zbarsky [:bzbarsky]]

j.j, please don't nuke other people's whiteboard annotations.  They're used to track bugs and such...

Comment 28

[Stephen Williams]

I'd like to take this bug and suggest a fix.

If the following was introduced as css defaults the problem will go away.

  -moz-border-*-colors: transparent;

Also the following change in about:config fixes it but is potentially much more impactful (not backwards compatible, etc).

  gfx.direct2d.force-enabled = true

Could someone point me in the direction of how to make this change and submit it? This would be my first contribution to the community.

Comment 29

[Stephen Williams]

Also this bug is still present in 8.0

Comment 30

[Bas Schouten (:bas.schouten)]

(In reply to Stephen Williams from comment #28)
> 
> Also the following change in about:config fixes it but is potentially much
> more impactful (not backwards compatible, etc).
> 
>   gfx.direct2d.force-enabled = true

Don't wanna do this! There's a reason we block cards and don't use Direct2D with them, there's no telling what could go wrong. :)

Comment 31

[Stephen Williams]

Still present in 9.0.1

Comment 32

[Jess Telford]

Still present in FF 13.0a1 (2012-02-28) Nightly.

Comment 33

[Jess Telford]

Attachment: testcase

This test-case exhibits the buggy behaviour for me (the other did not).

Comment 34

[Loic]

I tested in Nightly Mozilla/5.0 (Windows NT 6.1; WOW64; rv:14.0) Gecko/20120415 Firefox/14.0a1 and it's present if I disable HWA, so likely a bug with Cairo.

I tried to find a regression range, i.e. a build from which the gray border doesn't appear even if HWA is disabled:

m-c
good=2010-12-02
bad=2010-12-03
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=baa5ae44f0ba&tochange=0ff6d5984287

Maybe someone could confirm, but I think the regression is in:
Bug 588271 - Improve border rendering code for running on GPUs

Comment 35

[Alice0775 White]

Confirmed with HWA off.

Regression window:
Cannot reproduce
http://hg.mozilla.org/mozilla-central/rev/7ab0eb4c345b
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b8pre) Gecko/20101201 Firefox/4.0b8pre ID:20101202051834
Can eproduce:
http://hg.mozilla.org/mozilla-central/rev/ae06445eeff1
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b8pre) Gecko/20101202 Firefox/4.0b8pre ID:20101202052608
Pushlog:
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=7ab0eb4c345b&tochange=ae06445eeff1


Note:
I can also reproduce in Nightly14.0a1(Aurora 13.0a2 and Firefox12.0 as well) with enabled HWA and gfx.content.azure.enabled = true.
I filed new Bug 745709.

Comment 36

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

http://coderwall.com/p/tpmsta is a blog post (that Asa found) about this bug

Comment 37

[Ida Franceen]

Still present in Firefox 16.0.1 (Windows 7)
Please fix this soon.

Comment 38

[sarbbottam]

The bug exists on FF 17.0.1 (Windows 7) too, can we get this fixed please?

Comment 39

[Alexander Makarov]

This one is related to 644104.

Comment 40

[Paul Silaghi, QA [:pauly]]

Still an issue on FF 25.0a1 (2013-07-16), NVIDIA GeForce 8400 GS, HWA off

Comment 41

[roxleitan]

20160502172042 Mozilla/5.0 (Windows NT 6.1; rv:46.0) Gecko/20100101 Firefox/46.0
20160518030234 Mozilla/5.0 (Windows NT 6.1; rv:49.0) Gecko/20100101 Firefox/49.0

I have tested your issue in Windows 7 on latest FF release 46.0.1 and latest Nightly build and could not reproduce it. 

Is this still reproducible on your end ? If yes, can you please retest this using latest FF release and latest Nightly build (https://nightly.mozilla.org/) and report back the results ? When doing this, please use a new clean Firefox profile, maybe even safe mode, to eliminate custom settings as a possible cause (https://goo.gl/PNe90E).

Comment 42

[Alexander Makarov]

The issue is gone in latest version.