2 bugs on jQuery.fn.add

[flesler]

As mentioned ​here, $.fn.add is not calling $.unique, thus elements can get duplicated.

Also, the array-like detection is very naive, and will fail when receiving a form, or the window if iframes are included.

That's why I change it so that it uses makeArray, which does smarter sniffing on array-like.

This also makes the code shorter.

[flesler]

UPDATE:

I just got into the scariest IE quirk. Just realized that form == form.elements. They're literally the same, can't differentiate them. I decided (to keep this working as it was) that $(form) will consider it a form, but $.makeArray(form) will generate an array of elements, this is the behavior of $.fn.add.

In short, $.fn.add does a naive check, will mess up with $().add(window) and any other thing with length.

[flesler]

Tests that can now pass

[flesler]

Noticed that one test of .html() fails on IE with this patch, because the created element gets the expando, so the resulting .html() includes it and is different than expected.

This shouldn't be relevant.

In conclusion, do we want to call .unique() inside .add() ??

[scott.gonzal]

This change looks good to me. makeArray should be used wherever possible and the added call to unique seems like expected behavior.

[joern]

There is nothing fun as the form element in IE.

Agreed with Scott!

[flesler]

Applied at [5503] and extra tests at [5504].