Closed
Bug 618827
Opened 14 years ago
Closed 13 years ago
JS: instanceof fails when object's constructor is initialized from an iframe
Categories
(Core :: XPConnect, defect)
Tracking
()
RESOLVED
FIXED
| Tracking | Status | |
|---|---|---|
| blocking2.0 | --- | betaN+ |
People
(Reporter: bkon, Assigned: gal)
Details
(Keywords: regression)
Attachments
(1 file)
|
385 bytes,
text/html
|
Details |
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.10 (KHTML, like Gecko) Chrome/8.0.552.215 Safari/534.10
Build Identifier: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b7) Gecko/20100101 Firefox/4.0b7
When an object constructor is initialized from an iframe, instanceof incorrectly returns false when applied to an recently created object.
Reproducible: Always
Steps to Reproduce:
1. Create a sample html file with contents displayed below:
<body>
<script type="text/javascript">
var iframe = document.createElement("iframe");
iframe.style.display = "none";
document.body.appendChild(iframe);
// write a script into the <iframe> and steal its Array object
frames[frames.length - 1].document.write(
"<script>parent.XXX = Array;<\/script>"
);
var newItem = new XXX();
console.log(newItem instanceof XXX);
</script>
</body>
2. Open FF Beta
3. Open web console
4. Load the sample file (doesn't matter if it's loaded via file:// or via http://
5. Note the output displayed in the web console (by the last line inside the script)
Actual Results:
"false" displayed in the web console.
Expected Results:
"true" displayed in the web console.
|
||
Updated•14 years ago
|
Summary: JS: instanceof fails when object's constructor is initialized from an inframe → JS: instanceof fails when object's constructor is initialized from an iframe
|
||
Updated•14 years ago
|
Component: General → DOM
Product: Firefox → Core
QA Contact: general → general
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||
Comment 1•14 years ago
|
||
Hmm. That's odd, but doesn't seem like a DOM issue; more likely a problem with wrappers.
Status: UNCONFIRMED → NEW
blocking2.0: --- → ?
Component: DOM → XPConnect
Ever confirmed: true
Keywords: regression
QA Contact: general → xpconnect
|
||
Updated•14 years ago
|
Assignee: nobody → mrbkap
blocking2.0: ? → betaN+
|
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Comment 2•14 years ago
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mrbkap says this is a dupe of bug 597872.
Status: NEW → RESOLVED
Closed: 14 years ago
Resolution: --- → DUPLICATE
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Reporter | |
Comment 3•13 years ago
|
||
Still reproducible in Firefox 4 Beta 10 (which already contains fix for the bug 620486)
Status: RESOLVED → REOPENED
Resolution: DUPLICATE → ---
|
Assignee | |
Updated•13 years ago
|
Assignee: mrbkap → gal
|
|
Assignee | |
Comment 4•13 years ago
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Looking at this.
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Assignee | |
Comment 5•13 years ago
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Assignee | |
Comment 6•13 years ago
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Ok, this is false for us, false for safari, and true for chrome. I couldn't get opera to display anything.
|
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Comment 7•13 years ago
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What about IE? And presumably this was true in Gecko 1.9.x?
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Assignee | |
Comment 8•13 years ago
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I am not saying I won't fix this. I just noted the weird behavior for now.
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Assignee | |
Comment 9•13 years ago
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An independent bug causes that instanceof to still fail, filed as 631135 with the same testcase.
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Assignee | |
Updated•13 years ago
|
Status: REOPENED → RESOLVED
Closed: 14 years ago → 13 years ago
Resolution: --- → FIXED
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Reporter | |
Comment 10•13 years ago
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It's true in Firefox 3.6.13, IE8, IE8 in "IE7 compatibility mode", replacing console.log() with alert() in the original source makes Opera display "true" as well.
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Description
•