Inconsistency between has [attribute] selector and attr() method

[jitter]

While checking on #7480 I noted a related bug.

There are inconsistencies when using the has [attr] selector and the attr() method.
The selector doesn't return all elements which have the attribute although upon checking with the attr() method it returns a value.

​test case with text attribute not explicitly defined
​test case with text attribute explicitly defined on some elements

[snover]

This is something on the roadmap for 1.5. .attr will be rewritten along with Sizzle to stop matching on the DOM properties, so this will all be happily consistent again.

[john]

This is getting moved to 1.6 for when the $.attr happens.

[Timmy Willison]

I think #7128, #5930, and #5637 are duplicates of this issue, but I'm not 100% on that.

[Timmy Willison]

The nodes in question do not have content attributes called "text" and therefore should not be found by either one. ​http://jsfiddle.net/timmywil/znVBU/2/