:contains() selector doesn't support parentheses

[Sanity]

So, it seems I don't actually need quotes when using contains:

$(':contains(foo)') works as expected.

$(':contains("foo")') does the exact same thing.

$(':contains("(foo")') dies with: Syntax error, unrecognized expression: "(assembling")

So I have to wonder, what is the point of the quotes if they don't actually escape anything? Should they be dropped, or should this be fixed to allow parens?

[mynameissam@…]

I'm seeing the same issue too. Escaping the parentheses doesn't work. Below is a jsFiddle test case that will replicate the bug:

 http://jsfiddle.net/vXSKm/1/

[snover]

Duplicate of #5482.