924665 - BackgroundPageThumbs captures can finish twice

Status: RESOLVED FIXED

(Toolkit :: General, defect)

Description

[Drew Willcoxon :adw]

Attachment: patch

Bug 913171 moved the captureCallback call after _store completes, which is fine, but it also moved the destroy call, which introduces the possibility of _done being called twice: first on successful completion, and then, while the _store is pending, again when the timeout timer fires and calls notify.  destroy has to happen synchronously with the _done call so that _done isn't called twice.

Unrelatedly, destroy contains an erroneous Services.ww.unregisterNotification(this) that's left over from when we were using PB mode, so this patch also removes that.

Patch is based on bug 924651.

Comment 1

[Drew Willcoxon :adw]

https://hg.mozilla.org/integration/fx-team/rev/daa8fbedef2f

Comment 2

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/daa8fbedef2f

Comment 3

[Drew Willcoxon :adw]

Comment on attachment 814618 [details] [diff] [review]
patch

[Approval Request Comment]
Bug caused by (feature/regressing bug #): Bug 913171
User impact if declined: minimal
Testing completed (on m-c, etc.): tryserver with this patch and two, related others I'd like to uplift: https://tbpl.mozilla.org/?tree=Try&rev=c8eda3703066
Risk to taking this patch (and alternatives if risky): low
String or IDL/UUID changes made by this patch: none

Patch applies cleanly to Aurora.

Comment 4

[Drew Willcoxon :adw]

Comment on attachment 814618 [details] [diff] [review]
patch

Whoops, I meant to cancel these approval requests earlier today.  We're not planning on uplifting this anymore because we're not going to uplift bug 927688 to Aurora/26 after all.

I won't undo the a+, but again, we decided not to uplift this.