1318625 - Dotted border rendering artifacts when setting elliptical shaped corner

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Massamino]

Attachment: Right top border radius set to 40px 200px on 200px sized div

When setting top and bottom border width to a value and setting the side borders to 0 and than setting the top right border radius to 40px 200px, the rendering of the border goes wrong.

It shows an overshoot after half the height of the div.

Comment 1

[Massamino]

Attachment: Image of rendering error

To see the result I get (dashed is ok)

Comment 2

[Julien Wajsberg [:julienw]]

I reproduce with latest Aurora v51 (20161114004005) and latest Nightly v53 (20161117030212).

Comment 3

[Tooru Fujisawa [:arai]]

thanks.
I found that the DottedCornerFinder goes into wrong state after the dot size becomes almost 0.
Will try fixing.

Comment 4

[Tooru Fujisawa [:arai]]

Attachment: Stop calculating circles around r=0 in DottedCornerFinder.

While calculating circle around r=0, it may fail to search correct circle (due to the restriction for avoid taking too long time), and in that case it returns wrong circle that is bigger than previous circle (note that we're calculating circles from wider side to narrow side),

So changed the code to detect that case and stop calculating.
it will now return circle with r=0, so that nsCSSBorderRenderer::DrawDottedCornerSlow will leave the loop.


I'll try creating reftest, but it may take some time, so I'd like to ask review for the code first.

Comment 5

[Tooru Fujisawa [:arai]]

Attachment: Part 2: Add testcase.

Added testcase from comment #0.

Comment 6

[Tooru Fujisawa [:arai]]

Thank you for reviewing :)

Comment 7

[Tooru Fujisawa [:arai]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/2405181a4bf97a0f8f8c3588ad373d98a21d159d
Bug 1318625 - Part 1: Stop calculating circles around r=0 in DottedCornerFinder. r=0 in DottedCornerFinder.,jrmuizel

https://hg.mozilla.org/integration/mozilla-inbound/rev/16c4898b35b2fbb4a3482e5162764d5b29ae3d18
Bug 1318625 - Part 2: Add testcase. r=jrmuizel

Comment 8

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/2405181a4bf9
https://hg.mozilla.org/mozilla-central/rev/16c4898b35b2

Comment 9

[Tooru Fujisawa [:arai]]

Comment on attachment 8812310 [details] [diff] [review]
Stop calculating circles around r=0 in DottedCornerFinder.

same patch is applicable to mozilla-aurora and mozilla-beta

Approval Request Comment
> [Feature/regressing bug #]
bug 382721

> [User impact if declined]
unnecessary wrong dots are rendered with dotted border radius in some case.
(comment #0)

> [Describe test coverage new/current, TreeHerder]
tested on m-c

> [Risks and why]
low, just avoid rendering wrong dots

> [String/UUID change made/needed]
none

Comment 10

[Gerry Chang [:gchang]]

Comment on attachment 8812310 [details] [diff] [review]
Stop calculating circles around r=0 in DottedCornerFinder.

Fix a rendering issue related to dotted border radius. Beta51+ and Aurora52+. Should be in 51 beta 3.

Comment 11

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/e3fb37a9876c
https://hg.mozilla.org/releases/mozilla-aurora/rev/c538edad135a

Comment 12

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/releases/mozilla-beta/rev/37a277bc5986
https://hg.mozilla.org/releases/mozilla-beta/rev/fa3e6456dd1e

Comment 13

[Mohammad Maruf Islam]

I have reproduced this bug with Firefox Nightly 53.0a1 (Build ID: 20161118030222) on 
Windows 8.1, 64-bit.

Verified as fixed with Latest Firefox beta 53.0b5 (Build ID: 20170320143328)
Mozilla/5.0 (Windows NT 6.3; WOW64; rv:53.0) Gecko/20100101 Firefox/53.0