640912 - Fix local scoping of nsITimer in searchCommon.js that is susceptible to GC before firing

Status: NEW

(Thunderbird :: Search, defect)

Description

[Mark Banner (:standard8)]

+++ This bug was initially created as a clone of Bug #640629 +++

When timers are created, there is no extra reference held until they fire.  That means that if the variable storing the timer object goes out of scope, it's susceptible to a GC which will destroy the timer without it ever firing.


There's an instance of this in searchCommon.js in SearchSupport.observe. It looks like a fallback case, so we probably won't hit it too often, but worth fixing anyway.

Comment 1

[Wayne Mery (:wsmwk)]

hmm. What UI behavior might a user see as a result of a GCed timer? Crash?

Comment 2

[Mark Banner (:standard8)]

(In reply to comment #1)
> hmm. What UI behavior might a user see as a result of a GCed timer? Crash?

The action just wouldn't complete. In this case the timer is in a call that is handling failure of registration (or deregistration) of the search stuff. So worse case we'd just not disable it in preferences.

You're probably also very unlikely to hit it. You've got 200ms from that failure to when the timer fires. We don't do gc that often.

Comment 3

[(no longer active)]

Ah, this bug's number is too similar to bug 649012.  Sorry!