595092 - Attempting to access the extensions datasource too early in startup will fail and leave the datasource inaccessible for the entire session

Status: RESOLVED FIXED

(Toolkit :: Add-ons Manager, defect)

Description

[Dave Townsend [:mossop]]

If _ensureDS is called before ProfD is available we end up defining _ds but it has no datasource loaded in it so all attempts to use it will throw exceptions.

We can protect against this quite easily and we should as if extensions do this it currently leaves the extension manager, blocklist service and app updates broken.

Comment 1

[Dave Townsend [:mossop]]

Attachment: patch rev 1

This keeps the add-ons manager in a sane state if the datasource is accessed before ProfD is available. Accessing the datasource at that point will still throw but we no longer cache the bad datasource we get and allow it to be recreated at a future time.

The test was a bit tricky, putting it into the same directory as the others would make it impossible to test as a profile directory is always defined there, and I had to define ProfDS since that is always available by the time the extension manager can be accessed.

Comment 2

[Dave Townsend [:mossop]]

Comment on attachment 474200 [details] [diff] [review]
patch rev 1

This patch is a protective measure to help us be resilient in the face of extensions doing weird things. In introduces no behavioral change for the normal case and includes an automated test to verify that it fixes the breakage that we'd normally see here.

Comment 3

[Dave Garrett]

Is a backport to 1.9.1 needed, possible, or even doable before its EOL?

Comment 4

[Dave Townsend [:mossop]]

The patch probably applies as-is, not sure how worth it it is at this point though.

Comment 5

[Dave Garrett]

There's some complaining about the Personas Plus 1.6 mess under Firefox 3.5.x in bug 590978 (which was just set to blocking both 1.9.2 and 1.9.1), so if this is doable on both branches without too much trouble then it's probably worth it.

Comment 6

[Dave Townsend [:mossop]]

(In reply to comment #5)
> There's some complaining about the Personas Plus 1.6 mess under Firefox 3.5.x
> in bug 590978 (which was just set to blocking both 1.9.2 and 1.9.1), so if this
> is doable on both branches without too much trouble then it's probably worth
> it.

The personas extension doesn't override the extension manager in 3.5 so in that particular case 3.5 is unaffected.

Comment 7

[Dave Garrett]

(In reply to comment #6)
> (In reply to comment #5)
> > There's some complaining about the Personas Plus 1.6 mess under Firefox 3.5.x
> > in bug 590978 (which was just set to blocking both 1.9.2 and 1.9.1), so if this
> > is doable on both branches without too much trouble then it's probably worth
> > it.
> 
> The personas extension doesn't override the extension manager in 3.5 so in that
> particular case 3.5 is unaffected.

Then I guess the blocking1.9.1.13+ in bug 590978 is unwarranted, which was why I asked here.

If this patch won't hurt but might help, and requires no extra effort to backport, then I'd suggest landing it there just in case. If there's a noteworthy risk, then nevermind.

Comment 8

[Daniel Veditz [:dveditz]]

Comment on attachment 474200 [details] [diff] [review]
patch rev 1

Approved for 1.9.2.11, a=dveditz for release-drivers

Comment 9

[Dave Townsend [:mossop]]

Landed on the branch: http://hg.mozilla.org/releases/mozilla-1.9.2/rev/a47ecaf1f779

Comment 10

[Al Billings [:abillings - ex-MoCo]]

How do we test this fix in 1.9.2? Is there a way to reliably trigger the original issue?

Comment 11

[Henrik Skupin [:whimboo][⌚️UTC+2]]

(In reply to comment #10)
> How do we test this fix in 1.9.2? Is there a way to reliably trigger the
> original issue?

Dave, any chance to get it verified manually?

Comment 12

[Dave Townsend [:mossop]]

(In reply to comment #11)
> (In reply to comment #10)
> > How do we test this fix in 1.9.2? Is there a way to reliably trigger the
> > original issue?
> 
> Dave, any chance to get it verified manually?

The most straightforward way would probably be to try to reproduce bug 590608