758756 - XPConnect confused by (controller) objects which don't implement QueryInterface()

Status: RESOLVED INACTIVE

(Core :: XPConnect, defect)

Description

[Serge Gautherie (:sgautherie)]

(In reply to [e-mail] from bug 756572 comment #17)
> This is an XPConnect bug.
> 
> When showing the popup, we query for the popup state, which flushes layout.
> This then decides to go a delete a bunch of frames, presumably for the
> hidden location bar. Then (presumably) the inner input element then tries to
> clear the command context on all of its controllers.
> 
> Now, not all controllers have a command context. So, they call get
> QueryInterface called on them to find out whether they do. But, there's a
> controller that doesn't have a QueryInterface method on it. And the way that
> XPConnect now uses to call QueryInterface causes a strict JS warning when
> QueryInterface doesn't exist. Worse, the warning gets reported for the
> original property access, which is actually now being executed...


(In reply to [e-mail] from bug 756572 comment #21)
> (In reply to Serge Gautherie from comment #19)
> > Are you saying that XPConnect should just silently ignore the missing
> > QueryInterface?
> Yes; normally you don't need a QueryInterface to pass a JS object to a C++
> object, as long as the JS object has all the other methods it's OK.


In short:
Idea 1. Should not report this case :-)
Idea 2. At least, should be more explicit than currently confusing :-|
Idea 3. At least maybe make this case mandatory (as an (documented) error) :-/
Idea 4. If all fails, then we're in some trouble...

Comment 1

[BMO Automation]

Per policy at https://wiki.mozilla.org/Bug_Triage/Projects/Bug_Handling/Bug_Husbandry#Inactive_Bugs. If this bug is not an enhancement request or a bug not present in a supported release of Firefox, then it may be reopened.