set_post_format: inconsistency between edit_post and bulk_edit_posts

[Chouby]

In edit_post(), set_post_format() is called before the post is saved. In bulk_edit_posts(), it is called after.

This can cause trouble to the plugins expecting to have the right post format, when hooking to the action save_post.

[SergeyBiryukov]

Introduced in [18722].

[SergeyBiryukov]

Simply moving set_post_format() call above wp_update_post() is not enough, as wp_insert_post() then overwrites the format​ with the old data from $post_data['tax_input']['post_format'].

41396.2.diff​ adds unset( $post_data['tax_input']['post_format'] ) and a unit test.

[SergeyBiryukov]

In 41187:

Post Formats: In bulk_edit_posts(), set post format before the post is updated, for consistency with edit_post().

This makes sure that plugins hooked to save_post get the right post format.

Props Chouby, SergeyBiryukov.
Fixes #41396.

[SergeyBiryukov]

#34764 was marked as a duplicate.

[SergeyBiryukov]

In 44670:

Post Formats: Prevent Bulk Edit from unintentionally changing post format to Standard even if set to "No change".

Correct the logic in [41187].

Props birgire, mukesh27, lanche86.
Fixes #44914. See #41396.