jQueryObject.find(element) corrupts the stack

[Olson.dev@…]

Version: 1.7.2

Browser: Chrome 21 dev, Firefox 14

OS: Windows 7 64-bit

Step-by-step: ​http://jsfiddle.net/usY7W/

Expectation: I should be able to chain $(blah).find(element).andSelf().filter(element) and effectively check if blah or its descendants contain element.

Actually happens: $(blah).find(element).andSelf().filter(element).length is always 1 because .find(element) corrupts the stack and .andSelf().filter(element) is always a jQuery object only wrapping element

[anonymous]

I fixed some logic and removed redundant CSS. ​http://jsfiddle.net/usY7W/3/

[dmethvin]

The "problem line" boils down to this:

$(this).find(e.target).andSelf().filter(e.target)

That will either be 0 or 1 elements. Since the event has bubbled to this it would seem like event.target must be either this or one of its descendants so the result will always be e.target. So I have no idea what you're trying to do here, or what "corrupts the stack" means. Please ask for help on the forum.

[Olson.dev@…]

Don't confuse yourself; this has nothing to do with the bubbling. See the jsFiddle below with an even simpler example (sorry for not reducing it even further in the first place).

The problem is the implementation of jQuery.fn.find, particularly this section:

if (typeof selector !== "string") {
    return jQuery(selector).filter(function () {
        for (i = 0, l = self.length; i < l; i++) {
            if (jQuery.contains(self[i], this)) {
                return true;
            }
        }
    });
}

Internally jQuery keeps a context stack. Every traversal should push the previous context on the stack. That's what makes jQuery.fn.andSelf() work.

Because $(this).find(someElement) hits that block of code above, the stack becomes corrupted. That is, it effectively starts all over.

Thus, the next operation, .andSelf() is going to make return a jQuery object only wrapping someElement. Then when .filter(someElement) gets executed, it's obviously always going to return a jQuery object with a length of 1.

Here's a simpler demonstration of the problem: ​http://jsfiddle.net/295X6/

It all has to do with WHAT you pass into jQuery.fn.find().

[Olson.dev@…]

​http://jsfiddle.net/295X6/1/ made the output more intuitive...

[dmethvin]

Okay, that example makes a lot more sense.

[mikesherov]

​https://github.com/jquery/jquery/pull/927/

[Mike Sherov]

Fix #12009. $().find( DOMElement ) should pushStack properly. Close gh-927.

Changeset: e8f91514a6f353e85d8117998087903dc7331210