327156 - [FIX]|window instanceof X| throws a lot (e.g. if window is not an instance of X)

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect, P2)

Description

[Boris Zbarsky [:bzbarsky]]

The problem is that the classinfo for Window has:

    DOM_CLASSINFO_MAP_ENTRY(nsIDOMEventReceiver)

But that's not a scriptable (or indeed IDL!) interface.  So in nsDOMConstructor::HasInstance when we call GetInfoForIID() on that interface we of course get nothing back.  That causes:

###!!! ASSERTION: nsDOMConstructor::HasInstance can't get interface info.: 'Error', file ../../../../mozilla/dom/src/base/nsDOMClassInfo.cpp, line 4804

followed by a throw.

In other words, the only way "window instanceof X" doesn't throw is if X is Window, JSWindow, or WindowInternal.

It seems to me like the right way to fix this is to remove the classinfo for nsIDOMEventReceiver... or am I missing something?  The other option would be to silently continue on lack of interface info, if we do need that interface in classinfo for window (or other non-idl interfaces in other classinfos).

This isn't a recent regression or anything, which frankly amazes me.

Comment 1

[Boris Zbarsky [:bzbarsky]]

Not sure about fixing on 1.8.0 branch, but we should fix on 1.8.1, imo.

Comment 2

[Boris Zbarsky [:bzbarsky]]

*** Bug 310344 has been marked as a duplicate of this bug. ***

Comment 3

[Boris Zbarsky [:bzbarsky]]

Attachment: Fix

Comment 4

[Johnny Stenback (:jst)]

Comment on attachment 218129 [details] [diff] [review]
Fix

r+sr=jst

Comment 5

[Boris Zbarsky [:bzbarsky]]

Fixed trunk and 1.8.1 branch.