Invalid jQuery selectors causing errors in IE8 using updated jQuery (1.7 + )

Sorry, haven't checked up on the thread in a while. I had seen some discussion on the handling of quotes in attribute selectors, unfortunately can't remember where this was. I don't think I highlighted enough that this is only specific to jQuery 1.7+ on IE<8, non quoted attribute selectors ARE valid, but seemingly not properly supported in older IE versions.

A curious note on this page:
http://api.jquery.com/category/selectors/attribute-selectors/

States that only simple identifiers should be unquoted, could be that the ":" in "mailto:" disqualifies it?

Attribute values in selector expressions must follow the rules for W3C CSS selectors, in general that means anything other than a simple identifier should be surrounded by quotation marks.

double quotes inside single quotes: $('a[rel="nofollow self"]')
single quotes inside double quotes: $("a[rel='nofollow self']")
escaped single quotes inside single quotes: $('a[rel=\'nofollow self\']')
escaped double quotes inside double quotes: $("a[rel=\"nofollow self\"]")

Every example on that page also uses quotes.

Are you able to replicate the bug/solution in IE8?

Thanks for the feedback, I wasn't entirely sure on their usage of 'simple identifier' either, it seems to be any alphanumeric string, so as soon as punctuation is used (e.g ":" or a space), it needs to be quoted. I'm not entirely sure it's a jQuery bug.

Quote from this page (It appears to have been a change in or around 1.6)
http://bugs.jquery.com/ticket/9351#comment:2

Take a look at the api, there have been some changes made in the last 6 months or so regarding attribute selectors, most notably that jQuery requires quotes around the attribute value of the selector http://api.jquery.com/attribute-equals-selector/

And again on the API reference:
http://api.jquery.com/attribute-equals-selector/

jQuery('[attribute="value"]')

attribute
An attribute name.
value
An attribute value. Can be either an unquoted single word or a quoted string.

I think it comes back to "mailto:" not being an alphanumeric 'word', and should be treated as a string.

Quoting the attribute value works on all versions of jQuery, I think it'd be a worthwhile update to the module as the version of jQuery that is available is not guaranteed to be the version included in Drupal core.

Not sure that's necessary, I think the following references should clear it up.

As before, from the Attribute Selector API page
http://api.jquery.com/category/selectors/attribute-selectors/

Attribute values in selector expressions must follow the rules for W3C CSS selectors, in general that means anything other than a simple identifier should be surrounded by quotation marks.

After digging around on W3's CSS spec, I found the following information:

http://www.w3.org/TR/selectors/#attribute-selectors

Attribute values must be CSS identifiers or strings.

A CSS Identifier is defined here:
http://www.w3.org/TR/CSS21/syndata.html#value-def-identifier

In CSS, identifiers (including element names, classes, and IDs in selectors) can contain only the characters [a-zA-Z0-9] and ISO 10646 characters U+00A0 and higher, plus the hyphen (-) and the underscore (_); they cannot start with a digit, two hyphens, or a hyphen followed by a digit. Identifiers can also contain escaped characters and any ISO 10646 character as a numeric code (see next item). For instance, the identifier "B&W?" may be written as "B\&W\?" or "B\26 W\3F".

A CSS String can be anything in the charset, inside quotes.

So, "mailto:" contains characters outside of [a-zA-Z0-9], "-", "_" and doesn't qualify as an Identifier, suggesting it must be passed as a string, with quotes. It might be possible to escape the colon also, but I haven't tested this. e.g:

a[href^=mailto\: