1884677 - Regression: webextension content_scripts ignored in FF 123, work in 115.8.0esr

Status: RESOLVED INVALID

(WebExtensions :: Untriaged, defect)

Description

[Graham Leggett]

Attachment: 99af54beef1241d589e1-0.9.1.xpi

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.4 Safari/605.1.15

Steps to reproduce:

Install a manifest V2 webextension in Firefox 123 running on Fedora Rawhide, by placing the extension in the following directory:

/usr/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/[e-mail]

Actual results:

Content scripts do not run, they do not appear in the debugger, as a result the extension has no effect.

This used to work in Firefox 115.8.0esr.

Expected results:

Content scripts are run, the extension has an effect.

Comment 1

[Graham Leggett]

More experimenting.

If the signed extension is removed from the /usr/share/mozilla/extensions/ directory, and the identical signed XPI file is loaded via "Install add-on from file..", the content scripts in this case do run, but now the native extension is now silently broken.

To sum up:

• Extension loaded via "temporary extension": content scripts work, native works.

• Extension loaded via "Install add-on from file...", the content scripts run, but the native has no effect.

• Extension loaded via RPM in the /usr/share/mozilla/extensions/ directory, the content scripts do not run.

Key to this is that there is no UI/UX indicating anything is wrong, or disallowed. In all cases the extension appears in the extension list, and looks to be enabled and blessed by Firefox.

Comment 2

[Alex Cornestean]

Hello,

Sideloading is no longer possible since Firefox 74. However, sideloading is still supported on ESRs, according to https://blog.mozilla.org/addons/2020/03/10/support-for-extension-sideloading-has-ended/.
That’s probably why you observed the extension worked on Firefox 115.8.0esr and not on other Firefox versions.

I’ve tried sideloading the provided extension at /usr/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/[e-mail] and when I launch Firefox 123 there is no notification to enable the extension (as through this sideloading method, the extension will be installed but be disabled until the user enables it from the main menu). The extension is not installed at all.
On the other hand, on Firefox 115.8.0esr, as soon as I launch the browser, I see the notification in the main menu. Checking about:addons, shows the extension is installed and disabled, awaiting for me to enable it from the menu.

Can you confirm the extension is actually installed in Firefox 123 through that sideloading method? Thank you !

Comment 3

[Rob Wu [:robwu]]

Could you share the output of about:support ?

Could you clarify, is the add-on listed in about:addons?

Do you see any output in the global Browser Console?

Comment 4

[Luca Greco [:rpl] [:luca] [:lgreco]]

As Alex mentioned in comment 2 only ESR builds are still allowing addon sideloads (enabled here in moz.configure) and so Firefox 123 non ESR builds ignoring addon sideloads location is expected.

Closing as invalid, but let us know if you got any additional details that may suggest that the Firefox build being used is an ESR build and the sideload should be working.

Comment 5

[Graham Leggett]

To clarify, the "support for side loading has ended" described in https://blog.mozilla.org/addons/2020/03/10/support-for-extension-sideloading-has-ended/ is actually "extensions were spiked at runtime".

What should happen is that if side loaded extensions are genuinely unsupported, they should be completely ignored. Instead, they are discovered as usual, loaded, but then spiked at the last minute to make then not work. They then clash with an attempt to load the extension from the Firefox Addons site.

The effect of this is it makes it very difficult for the end user to swap from Firefox ESR to Firefox and back again.