Attribute Selector fails for defined attributes with wrong values in Mojo::DOM::CSS

[Akron]

Given a tag with a defined but value-less attribute like

<input type="text" name="example" value>

(for example generated using the taghelper plugin with $c->text_field('example', value => undef)),
the CSS selector

input[value="myname"]

will match regardless of the non-fitting value.
I tested the behaviour in Firefox and assume the selector should not match.
I added a test and a patch (although I doubt the patch is optimal).

Thank you!

[kraih]

Thanks, applied.