[whatwg] [Selectors4] case-insensitive attribute value matching (in XML)

Anne van Kesteren annevk at opera.com
Thu Feb 2 15:41:32 PST 2012

On Sat, 21 Jan 2012 16:23:31 +0100, Leif Halvard Silli  
<xn--mlform-iua at målform.no> wrote:
> Ian Hickson on Fri Jan 20 14:31:01 PST 2012:
>> On Tue, 26 Jul 2011, Christoph Päper wrote:
>>> Anne van Kesteren:
>>> > I'm still trying to get HTML and browsers to change so that attribute
>>> > values always match case-sensitively, irrespective of markup  
>>> language.
>>> > The current magic attribute list in HTML whose values needs to be
>>> > matched ASCII case-insensitively is just ugly.
>> The spec changed recently in response to Anne's efforts here. If this is
>> an area of interest, I encourage you to study the specification to see  
>> if
>> the current requirements are satisfactory.
> The matching rule for attribute names and element names, [1] doesn't
> match reality, see demo: [2]
> * Gecko uses ASCII case-insensitive matching (as specced by HTML5)
> * Trident/Webkit/Presto use Unicode caseless matching (variant).
>   (Legacy Firefox 3.6 behave like Trident/Webkit/Presto too.)
> The differences affect @data-* and @x-* (and other extensions).
> Shouldn't spec match Trident/WEbkit/Presto?

The HTML parser only lowercases A-Z so that behavior is somewhat  
surprising. Quick testing shows it also happens in the DOM (in  
Presto/WebKit at least). I think it should be treated as a bug in  
Trident/WebKit/Presto given how the HTML parser behaves, personally.

> [1] http://dev.w3.org/html5/spec/links#case-sensitivity
> [2] http://software.hixie.ch/utilities/js/live-dom-viewer/saved/1307

Anne van Kesteren

More information about the whatwg mailing list