712649 - Components.utils.getWeakReference(null) should fail silently (as it used to do)

Status: VERIFIED FIXED

(Core :: XPConnect, defect)

Description

[Giorgio Maone [:ma1]]

In 11 and above Components.utils.getWeakReference(null) throws NS_ERROR_FAILURE.
It used to fail silently instead, so it's probably breaking some clients (NoScript, for instance).
Also, since the value held by a weak reference will eventually be null anyway, allowing clients pass null may be seen as more consistent.

Comment 1

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

Attachment: Components.utils.getWeakReference(null) should fail silently;

I think it makes sense to allow this, but we should probably keep propagating other exceptions.

Comment 2

[Bobby Holley (:bholley)]

Comment on attachment 583499 [details] [diff] [review]
Components.utils.getWeakReference(null) should fail silently;

Looks good. r=bholley

We should get this in for 11 too, otherwise it sounds like we'll break extensions.

Comment 3

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

https://hg.mozilla.org/mozilla-central/rev/834bfdd83f70

Comment 4

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

Comment on attachment 583499 [details] [diff] [review]
Components.utils.getWeakReference(null) should fail silently;

This is a regression from bug 708330, which broke NoScript. The patch should be safe.

Comment 5

[Alex Keybl [:akeybl]]

Comment on attachment 583499 [details] [diff] [review]
Components.utils.getWeakReference(null) should fail silently;

[Triage Comment]
Approved for Aurora given the risk of regressing add-ons.

Comment 6

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

https://hg.mozilla.org/releases/mozilla-aurora/rev/bf34343622f4

Comment 7

[u279076]

Is there something QA can do to verify this fix? possibly involving NoScript?

Comment 8

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

I believe NoScript already works around this bug.

Comment 9

[Giorgio Maone [:ma1]]

(In reply to Ms2ger from comment #8)
> I believe NoScript already works around this bug.

Yes it does.

You can verify by running the following in the Error Console or in a chrome-scoped scratchpad:

try { alert("OK (" + Components.utils.getWeakReference(null) + ")") } catch(e) { alert("FAIL") }

Comment 10

[Virgil Dicu [:virgil] [QA]]

Mozilla/5.0 (Windows NT 5.1; rv:11.0) Gecko/20100101 Firefox/11.0
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:11.0) Gecko/20100101 Firefox/11.0
Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20100101 Firefox/11.0

Verified using guideline in comment 9 on Ubuntu 11.10, Mac OS 10.6, Windows XP (Firefox 11 beta 1). No failures.
All resulted in the following message in the Error Console:
"OK ([xpconnect wrapped xpcIJSWeakReference])"

Comment 11

[Virgil Dicu [:virgil] [QA]]

Mozilla/5.0 (X11; Linux i686; rv:12.0) Gecko/20100101 Firefox/12.0
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:12.0) Gecko/20100101 Firefox/12.0
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20100101 Firefox/12.0

Marking verified after checking on Firefox 12 beta 3 with the same guidelines from comment 9. 
Result: "OK ([xpconnect wrapped xpcIJSWeakReference])"

Comment 12

[Eric Shepherd [:sheppy]]

Documentation updated:

https://developer.mozilla.org/en/Components.utils.getWeakReference

Listed on Firefox 12 for developers.