`wp_update_term()` should mimic `wp_insert_term()` and set a value for `$term_group` before the `alias_of` logic runs. This ensures that `$term_group` exists when `compact()` is called.

See [28461].
Fixes #29278.

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git-svn-id: http://core.svn.wordpress.org/trunk@29325 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Media: Remove scan for lost attachments.

This hasn't been worked for 4 years.

fixes #29169.

Built from https://develop.svn.wordpress.org/trunk@29550


git-svn-id: http://core.svn.wordpress.org/trunk@29326 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Media Grid: Cleanup toggling of Next/Previous in Edit modal.

Fixes #29264.

Built from https://develop.svn.wordpress.org/trunk@29551


git-svn-id: http://core.svn.wordpress.org/trunk@29327 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Insert Media: Don't select a model if it's already selected.

props avryl, adamsilverstein.
fixes #29152.

Built from https://develop.svn.wordpress.org/trunk@29553


git-svn-id: http://core.svn.wordpress.org/trunk@29328 1a063a9b-81f0-0310-95a4-ce76da25c4cd
`wpmu_activate_signup()` returns an `array` or `WP_Error`. The array keys it returns can be different based on context of `$signup`. The return value was previously `extract()`'d, so the value of `$blog_id` was secretly undefined when being passed to `get_blogaddress_by_id()` in some cases.

If `$result['blog_id']` is not set, make sure `$url` is set to an empty string so that the proper "activated" message is shown to the user.

Props imath.
See [28373].
Fixes #29191.

Built from https://develop.svn.wordpress.org/trunk@29554


git-svn-id: http://core.svn.wordpress.org/trunk@29329 1a063a9b-81f0-0310-95a4-ce76da25c4cd