Closed Bug 736805 Opened 9 years ago Closed 2 years ago

"new X instanceof X" fails in Web Console

Categories

(Core :: XPConnect, defect)

defect
Not set
normal

Tracking

()

RESOLVED INACTIVE

People

(Reporter: emk, Unassigned)

References

Details

Steps to reproduce:
1. Press Ctrl+K to open Web Console.
2. Type "new MozBlobBuilder().getBlob() instanceof Blob" (without quote) and press Enter.
Actual result:
false
Expected result:
true

It works as expected in Web pages. It also works if I reverted <https://hg.mozilla.org/mozilla-central/rev/95a8eba120fe>.
This bug was not specific to Blob. "new MozBlobBuilder instanceof MozBlobBuilder" also returns false in Web Console.
OTOH, "new Array instanceof Array" returns true.
Keywords: regression
Summary: "instanceof Blob" fails in Web Console → "new X instanceof X" fails in Web Console
This may be related to bug 690529.
a = new window.Array
[]
a instanceof Array
false
a instanceof window.Array
true
bb = new window.MozBlobBuilder
[object MozBlobBuilder]
bb instanceof window.MozBlobBuilder
false

At least it should return consistent results.
This has nothing to do with the DOM per se; there are various security wrappers and whatnot all over here.
Component: DOM → XPConnect
QA Contact: general → xpconnect
Works for me now, leaving open to track adding a regression test.
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.
Status: NEW → RESOLVED
Closed: 2 years ago
Resolution: --- → INACTIVE
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