1374607 - Legacy add-on installed from disco pane while extensions.legacy.enabled=false

Status: RESOLVED WORKSFORME

(Toolkit :: Add-ons Manager, defect, P5)

Description

[Vasilica Tamas, QA [:vtamas]]

Attachment: 2017-06-20_1437.png

[Affected versions]:
Firefox 56.0a1 (2017-06-19)
Firefox 55.0b2 (20170615063713)
 
[Affected platforms]:
Windows 10 64-bit
Ubuntu 16.04 32-bit
 
[Steps to reproduce]:
1.Launch Firefox with a clean profile.
2.Navigate to about:config and toggle the value of extensions.legacy.enabled to false
3.Go to about:addons -> Get Add-ons and install a legacy add-on (e.g. uBlock Origin)
 
[Expected Results]:
The legacy add-on is not installed.
 
 
[Actual Results]:
- The confirmation doorhanger and the green switch button proves that the add-on was successfully installed.
- Only after a page refresh the button is switched off and the “Legacy Extensions” tab is displayed which contains the disabled add-on.
- See attached screenshot.

Comment 1

[Andrew Swan [:aswan]]

The issue here is that the AddonInstall api is kind of strange for incompatible addons.  The download succeeds (ie, the onDownloadEnded event is triggered) but the caller has to check the addon's .appDisabled property to notice that the extension is incompatible, in which case the caller is not supposed to continue the install.  mozAddonManager doesn't do that.
Ideally we would make this error condition look more like the other failure cases, but I suspect that could turn into a big project.  The quicker fix is just to add the right logic to mozAddonManager.
Note that the extension is never actually enabled, it just gets installed in a disabled state.  Still, this should be addressed.

Comment 2

[Andrew Swan [:aswan]]

I think the disco pane is only featuring webextensions these days so marking the priority accordingly.

Comment 3

[Andy McKay]

The mobile AMO page uses mozAddonManager and soon Desktop will too. I know its for legacy add-ons, but I think this will affect more than the disco pane. We might need to up the priority a bit.

Comment 4

[Andrew Swan [:aswan]]

But the current AMO pages don't show the "Add to Firefox" button for extensions that it knows are incompatible with the browser version that is viewing the page.  Assuming that it does the same thing for the mozAddonManager backed button and assuming that it does the right thing with legacy extension compatibility (as opposed to strictMaxVersions from manifests) then we should be okay here...

Comment 5

[Stuart Colville [:muffinresearch]]

I've filed https://github.com/mozilla/addons-frontend/issues/2888 to handle disabling the button for AMO / disco

Comment 6

[Graham Perrin]

Is this still an issue? Specifically: 

> Legacy add-on installed from disco pane …

Does that pane now present any legacy add-on? (I see none, viewed with 56.0.2.)


Side note: AMO
--------------

> … current AMO pages don't show the "Add to Firefox" button for extensions that it knows are incompatible with the browser version that is viewing the page. …

At the time of writing: classic and new looks _do_ show the button, to 56.0.2 where `extensions.legacy.enabled` is `false` and the add-on is compatible, but a click on the button is followed by blockage: 

> … could not be installed because it is not compatible with Firefox 56.0.2.

Comment 7

[Rob Wu [:robwu]]

AMO doesn't host legacy add-ons any more, so this bug can be closed.