191092 - Can't use |in| operator on collections or node lists

Status: RESOLVED WORKSFORME

(Core :: XPConnect, defect)

Description

[[e-mail]]

If you click on the URL provided you will see a false alert although any
document contains at least one tag. This applies to HTML collections and XUL
node lists.

Comment 1

[Boris Zbarsky [:bzbarsky]]

This is likely classinfo voodoo....

Comment 2

[Johnny Stenback (:jst)]

Yeah, I bet it is... feel free to push this over on my plate if nobody else
wants it. But do we really care? Are there real sites out there that breaks?
Sure it should be fixed, but how urgent is it? Does this work in IE?

Comment 3

[Phil Schwartau]

> Does this work in IE?
Yes - IE6 returns 'true' on the above javascript:URL

  javascript:alert(0 in document.getElementsByTagName('*'))

Comment 4

[[e-mail]]

The rationale:
editorUtilities.js currently has the code
var editorList = tmpWindow.document.getElementsByTagName("editor");

if (editorList && editorList.length > 0)
  return editorList[0];

Now editorList.length > 0 is expensive, but editorList[0] != null is a JS strict
warning if the tmpWindow has no editor elements. bz pointed out that there's a
workaround of editorList.item(0) != null but 0 in editorList would be neater.

Comment 5

[Johnny Stenback (:jst)]

With some definition of 'neater', maybe... :-)

Comment 6

[Andrew McCreight [:mccr8]]

These are presumably on WebIDL bindings now so they probably behave the way they are supposed to.

Comment 7

[Boris Zbarsky [:bzbarsky]]

Yes, this totally works now.