Plugin_Upgrader::deactivate_plugin_before_upgrade() is hooked to a filter, but doesn't always return a value

[jdgrimes]

Plugin_Upgrader::deactivate_plugin_before_upgrade() is hooked to the 'upgrader_pre_install' filter by Plugin_Upgrader::upgrade(), but it doesn't always return a value. This still works because the result of the filter is only checked with is_wp_error() (in WP_Upgrader::install_package()). However, it could certainly cause bugs for other functions hooked to that filter.

[azaozz]

In 30761:

Always return a value in Plugin_Upgrader::deactivate_plugin_before_upgrade(). Props jdgrimes. Fixes #29088.

[DrewAPicture]

Can we please get an @return description added to the DocBlock as well as a changelog entry that a return was added in 4.1.0?

[azaozz]

In 30762:

Better docs for Plugin_Upgrader::deactivate_plugin_before_upgrade(). Props DrewAPicture. Fixes #29088.