1419158 - border width display bug(page zoom + fractional pixels)

Status: NEW

(Core :: CSS Parsing and Computation, defect, P3)

Description

[AjiTae]

Attachment: border_bug.html

User Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0
Build ID: 20171112125346

Steps to reproduce:

1. Open page with no "meta charset" tag or with not-utf-8 charset. 
2. Zoom 200%.
3. Reload page(twice, to be sure).
4. Create element with 0.5px border-width or set this value to existing element.


Actual results:

We have 2px border displayed.


Expected results:

Border width must be ~1px.

Comment 1

[AjiTae]

Attachment: border_bug.mp4

Firefox 57+ affected.
I do not know how rendering and charset connected, but the fact is the only way to escape this bug(that I know) - set meta charset tag to utf-8.)

this particular case is case is hard to come by, but who knows what else is affected.)

Comment 2

[AjiTae]

In addition, as you can see on the screencast, resizing the window changes the rendering of new styles to the correct one.(but not for previously rendered)

Comment 3

[Matthias Versen [:Matti]]

Regression Range
Pushlog:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=5f721a664bf64fed99184a866b60c24a6afcb3a0&tochange=62cebea1d1578461a423a9ca7848706455db9ea5

Comment 4

[Nikki Pearson]

Attachment: same problem

Thanks from brazvieborrea1985.