Tree: saved open/closed state of one tree can interfere with another

[bill]

In Tree.js, postMixInProperties() does:

if(!this.cookieName){
	this.cookieName = this.id + "SaveStateCookie";
}

If the Tree doesn't have an id specified (ex: new Tree{{id: "foo"})), an id is auto-generated. The problem is that the auto-generation occurs after the code above runs.

Workaround: just specify an id on your trees

[bill]

But… if the Tree's ID is auto-generated I think we might be better off not doing any cookies, because an auto-generated id could easily change, or be duplicated across pages (for a multi-page application).

[bill]

Fixed in [24462], trac missed the commit again.

[Adam Peller]

Could there still be a collision problem with Trees running prior to 1.7 which had "SaveStateCookie?" recorded as a cookieName without an id?

[bill]

There should be no collision. Although that cookie may still be in users' browsers' caches, it won't be accessed. After upgrading to 1.7 Tree won't look for a cookie unless it has an explicit id, and in that case it will look for a different cookie name.

[bill]

In [28254]:

Don't try to save tree state if cookieName is undefined (which happens when there's no user specified id). Fixes #15088, refs #12735 !strict.