780366 - Borders not rendered correctly if border-widths or border-radius are large enough

Status: NEW

(Core :: Layout, defect)

Description

[vflash]

Attachment: o_transition.html

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:14.0) Gecko/20100101 Firefox/14.0.1
Build ID: 20120713134347

Steps to reproduce:

очень большой радиус


Actual results:

появились артефакты


Expected results:

должно быть как в webkit

Comment 1

[vflash]

http://vflash.ru/bug/o_transition.html

Comment 2

[vflash]

Attachment: screen

Comment 3

[Loic]

Could you explain the issue in English, please.

Comment 4

[vflash]

не знаю английского 
запустите пример и станет понятно
-------------------
I do not know English
Run the example and it becomes clear

Comment 5

[Boris Zbarsky [:bzbarsky]]

All the original comment says is "set a very large radius and you get rendering artifacts".  

Presumably in this case the large dark gray rectangles.

Note that the transitions are a red herring; they're not needed to reproduce the bug.

Comment 6

[Boris Zbarsky [:bzbarsky]]

Attachment: Much simpler testcase

Comment 7

[Boris Zbarsky [:bzbarsky]]

Is this a bug in nsCSSRendering or underlying gfx bug?  I see this on Mac, so I suspect the former...

Comment 8

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

Confirmed on Linux too.

Comment 9

[arni2033]

Attachment: testcase 3 - bug 780366 border width greater than 50 percent.htm

Only IE handles this testcase. It reveals that borders aren't drawn correctly (note the colored areas)

Comment 10

[arni2033]

I was wrong: there're cases when "border-width > 50% of border-box" isn't required.
I saved 4 testcases in my dropbox folder. Use the "index" page to open the testcases by direct links
> index:  https://dl.dropboxusercontent.com/s/h5zhs0gufq3ve9h/index.html?dl=0
> folder: https://www.dropbox.com/sh/hhf4wylz91tu86b/AAAfJ1stZNfh1s4a1UNH4y4ta?dl=0
Please correct me / undo changes if I did something wrong with this bug.