CSS3 transition property can affect the Admin Bar

[kwight]

Adding the transition property to, say, all anchors in a theme can affect Admin Bar elements. Explicitly setting transition to none can stop unexpected behaviour.

[kwight]

An example theme is Superhero (see L304 of style.css): ​http://wordpress.org/extend/themes/superhero

[SergeyBiryukov]

With proper formatting

[SergeyBiryukov]

This would be consistent with the previous CSS fixes in [17064], [17626], and [22280].

See ​CSS Coding Standards for the preferred formatting of vendor prefixes.

Do we also need -ms-transition? We use it in every other instance of transition properties in core.

[kwight]

The vendor prefix was used briefly in IE10, perhaps during development, but isn't necessary now: ​http://msdn.microsoft.com/en-us/library/ie/hh673535(v=vs.85).aspx

With or without the prefix, it's not supported at all in IE9 and below, according to my testing with this IE test page: ​http://ie.microsoft.com/testdrive/Graphics/hands-on-css3/hands-on_transitions.htm

[helen]

We should probably remove anything -ms-*, as it's not actually supported in any production/stable version of IE as far as I know.

[SergeyBiryukov]

In 23951:

Reset transition property in toolbar CSS to avoid conflicts with themes. props kwight. fixes #24031.