Enable maintenance mode when a plugin auto-updates

[desrosj]

Currently, when an active plugin is auto-updating, it remains active and the site does not enter maintenance mode.

This can cause a few issues:

• If a user loads the Plugins screen in the admin, the plugin could deactivate if an error is encountered mid upgrade.
• If a user loads the front end of the website and an error is encountered, the WSOD protection will be triggered sending a "false alarm" email to the site admin.

This is a spin-off of #48850 to tackle this in a smaller chunk.

Also potentially related: #34676.

[desrosj]

49400.diff​ uses the same approach that is used in the Theme_Upgrader class, hooking into the pre-install/post-install filters.

[SergeyBiryukov]

The documentation fixes in 49400.1.patch​ look good at a glance, but I'd like to make sure they're consistent with class-theme-upgrader.php.

Let's get 49400.diff​ in for now, and improve the docs after Beta 1.

[desrosj]

In 47275:

Upgrade/Install: Enable maintenance mode when plugins are auto-updated.

When an attempt is made to update an active plugin automatically, there is the potential currently for two negative scenarios:

• The plugin can be deactivated if the Plugins admin screen is loaded when the plugin update is incomplete, causing a PHP error.
• The WSOD protection could be triggered, sending a false alarm email to the site administrator.

By enabling maintenance mode before an active plugin update is attempted, these scenarios can be avoided.

This change implements the same approach as the Theme_Upgrader class of using the upgrader_pre_install and upgrader_post_install hooks to toggle maintenance mode.

Props desrosj, SergeyBiryukov.
Fixes #49400.

[desrosj]

Reopening to improve the inline documentation during beta.

[bookdude13]

Inline docs checked, slightly reformatted, and applied to the functions in class-theme-upgrader.php as well.

Side question, is there a reason the filters in class-plugin-upgrader.php's bulk_update() are different than update(), but in class-theme-upgrader.php they are the same?

[bookdude13]

Docs added for themes file as well

[garrett-eclipse]

@desrosj / @SergeyBiryukov
With auto-updates on plugins (#48850) having moved to 5.5 and the feature plugin should commit [47275] be reverted and this moved to the 5.5 milestone to align with the auto-updates functionality?

[desrosj]

Personally, I don’t feel this needs to be reverted. This is a self-contained enhancement to plugin auto-updates. While this feature has not been exposed through a UI in 5.4, site owners can still enable this with a filter.

On my personal sites, I have been seeing this work without issue since the day it was committed. I receive debug emails, and maintenance mode is correctly toggled before and after update.

If there is consensus to make all auto-update improvements in the same release, I’m fine with reverting. But this one is not coupled to the UI aspects, and will only prevent the two scenarios in the ticket description.

[desrosj]

That said, the documentation does still need to be updated.

[afragen]

How does this effect premium plugins or plugins not on dot org that contain their own updating code?

Deactivating them in the middle of an update could be very problematic.

[johnbillion]

This doesn't deactivate anything, it puts the site into maintenance mode (via wp_maintenance()).

@desrosj In that case I'm happy to leave the code in place. The revert was more to remove non-functional code, but if this can be utilised by plugins then I'm happy for it to stay in.

I'll review the docs changes and get those in.

[johnbillion]

In 47409:

Upgrade/Install: Improved inline docs for the plugin and theme updater maintenance mode functionality.

Props bookdude13

See #49400

[bookdude13]

@dkarfa should get props too, I mostly reformatted what he had already put in for docs.
Replying to johnbillion:

Props bookdude13

See #49400
}}}

[dkarfa]

Hey @bookdude13
Thank you
Debabrata

[johnbillion]

Apologies @dkarfa , my mistake.

I checked and as you've already gotten props on other changes in this release, you'll definitely be on the credits list for 5.4.

[SergeyBiryukov]

In 47414:

Docs: Correct formatting of some DocBlocks in Plugin_Upgrader and Theme_Upgrader per the documentation standards.

See #49400.

[dkarfa]

Much obliged @johnbillion . May be the quantity of check will be less.