Bug 91521 – Contained div with right 0 sometimes overlaps parent div

• Component: Layout and Rendering
• Status: RESOLVED FIXED

[Andrew Bachmann]

When viewing the attached URL at various zoom levels, the display changes and sometimes the right hand top of the button loses its border.

The attached image shows the effect in Chrome 22.0.1209.0 (146837) using WebKit 537.1 (@122718)

This manifests in our application with no zoom on some buttons but not other buttons.  It was first experienced in Chrome 21.0.1180.41 (Official Build 146467) beta using WebKit 537.1 (@122379)

It works okay in Chrome 20.0.1132.43 (Official Build 143823) beta using WebKit 536.11 (@121111)

Guess: subpixel rendering issue?

Bug 90097 looks relevant but the fix for that didn't fix this.

[Andrew Bachmann]

May be related to or same as bug 90281.

Reproduced on latest Chrome "nightly":

Chrome 22.0.1210.0 (Developer Build 146999)
WebKit	537.1 (@122833)

[Emil A Eklund]

Did you forget to attach an image?

[Andrew Bachmann]

Created attachment 153577 [details]
a button showing the effect

Attaching image of button showing the top right corner being clipped off. (in chrome, from jsfiddle linked in bug)

[Emil A Eklund]

I can reproduce this in 21.0.1180.49 but not a recent trunk build (22.0.1213.0) which makes me think one of the recent changes might have fixed this. Could you pelase retest on 22.0.1213 or later?

Thanks!

[Andrew Bachmann]

Created attachment 153854 [details]
200 percent zoom

[Andrew Bachmann]

Reproduced it at 110%,125% zoom level in this build:

Chromium	22.0.1216.0 (Developer Build 147907)
OS	Linux
WebKit	537.2 (@123338)
JavaScript	V8 3.12.14

Also at higher zoom levels such as 200% it is broken although less obviously so.  See attachement where the right hand side goes from "2 pixel" wide to "1 pixel".

[Emil A Eklund]

Thanks, I'll look into it.

[Emil A Eklund]

Created attachment 154375 [details]
minimal test case

Seems to be caused by the right: 0; rule, likely related to bug 89519.

[Emil A Eklund]

Created attachment 154697 [details]
Patch

[Levi Weintraub]

Comment on attachment 154697 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=154697&action=review

> Source/WebCore/rendering/RenderBox.h:205
> +    LayoutUnit clientLogicalWidth() const { return style()->isHorizontalWritingMode() ? clientWidth() : clientHeight(); }
> +    LayoutUnit clientLogicalHeight() const { return style()->isHorizontalWritingMode() ? clientHeight() : clientWidth(); }

I'm sad this went uncaught for so long!

[Eric Seidel (no email)]

Levi is a ninja.

[WebKit Review Bot]

Comment on attachment 154697 [details]
Patch

Clearing flags on attachment: 154697

Committed r123782: <http://trac.webkit.org/changeset/123782>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.

[Andrew Bachmann]

I have verified this as fixed for us in the nightly chromium build:

Chromium: 22.0.1223.0 (Developer Build 149222)
OS	Linux
WebKit	537.3 (@124188)
JavaScript	V8 3.12.18

Thanks for the fast turnaround!

[Emil A Eklund]

(In reply to comment #14)
> I have verified this as fixed for us in the nightly chromium build:
> 
Great, thanks for verifying.