Reinstate manage_pages_columns filter missing in wp_manage_posts_columns()

[studiograsshopper]

It looks like the abstraction work in wp-admin/includes/template.php, specifically in function wp_manage_posts_columns(), is missing the manage_pages_column filter. (There's a @todo at line 672).

This issue is related to #9674​https://core.trac.wordpress.org/ticket/9674

What about custom post types? Shouldn't they also have that filter present?

Updated to deal with custom post types

Oops! Forgot about custom post types. Ok, I've added something for custom post types, using the format manage_{$post_type}_columns. Since custom post types can be named anything, this seems the logical way to do it.

manage_{$post_type}_columns might not work as it might clash with other existing filters, such as one in get_column_headers() and 'manage_media_columns'.

This is a good start though. Just a style note, we generally put the variable on the right in comparisons, that way you don't accidentally do an assignment (see your first patch).

(In [13451]) Restore manage_pages_columns filter in wp_manage_posts_columns(). Pass post type to manage_posts_columns, and add a manage_{$post_type}_posts_columns filter. fixes #12398

Replying to nacin:

manage_{$post_type}_columns might not work as it might clash with other existing filters, such as one in get_column_headers() and 'manage_media_columns'.

This is a good start though. Just a style note, we generally put the variable on the right in comparisons, that way you don't accidentally do an assignment (see your first patch).

Thanks for pointing that out. :-)

[13451] introduces typos ($post_columns instead of $posts_columns) that break the enhancement.
The attached patch corrects those.

Patch to correct $post_columns typos

(In [13455]) Fix typos. props TobiasBg fixes #12398