Bug 111585 – [CSS Regions] The presence of a flow-from declaration in a CSS rule using :hover effectively disables the rule

• Status: RESOLVED
• Resolution: FIXED
• Component: CSS

[Mihai Balan]

If a CSS rule that uses the :hover pseudo-class tries to change the value of the flow-from property, that rule seems to be effectively ignored. Removing the flow-from declaration from the rule lets all other property changes to apply.

In the attached test-case, try moving the mouse over the green square.

EXPECTED: the green square should turn red (border color changes) and the black square should turn green (content is not flowed anymore and background color - green - is revealed)

ACTUAL: nothing happens

If the -webkit-flow-from: none; declaration is dropped from the #region:hover rule, the green square will turn red (border color changes).

[Mihai Balan]

Created attachment 191758 [details]
HTML file highlighting the problem

[Mihai Balan]

However, the rule is not actually disabled, since forcing the :hover state on the region (via the Web Inspector for instance), produces the expected results.

[Radu Stavila]

This is not a bug that affects just regions. Basically, changing any style in the :hover class that requires the element to be detached and reattached (such as changing it's display property) causes the :hover class to be ignored.

[Radu Stavila]

Linked issue: https://bugs.webkit.org/show_bug.cgi?id=7555

[Radu Stavila]

Created attachment 204014 [details]
Patch

The actual problem was fixed by https://bugs.webkit.org/show_bug.cgi?id=7555

This patch only adds tests for this particular problem (changing flow-from and flow-into inside :hover).

[Mihai Maerean]

Comment on attachment 204014 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=204014&action=review

> LayoutTests/fast/regions/hover-single-flow-from-none.html:47
> +			testRunner.notifyDone();

is this really needed? If you remove the calls to waitUntilDone and notifyDone, will the test still work?

> LayoutTests/fast/regions/hover-single-flow-from-other.html:54
> +			testRunner.notifyDone();

the previous comment applies to this test too.

[WebKit Commit Bot]

Comment on attachment 204014 [details]
Patch

Clearing flags on attachment: 204014

Committed r151311: <http://trac.webkit.org/changeset/151311>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.