add a wp_save_user pluggable api for plugin to choose where to save user

[fatihwk]

[Original description removed as it was just the attached patches in plain text]

[TobiasBg]

Thanks for your feature request.

Could you please elaborate and explain why and where this would helpful?
Couldn't this be achieved by changing the used database table in $wpdb already?
Also, wouldn't this require changes in the functions that retrieve a user from the database, too?

[SergeyBiryukov]

You can use CUSTOM_USER_TABLE and CUSTOM_USER_META_TABLE constants:
​http://codex.wordpress.org/Editing_wp-config.php#Custom_User_and_Usermeta_Tables

Generally, we tend to add filters instead of new pluggable functions, as they are much more flexible (see #8833).

[fatihwk]

I don't want to change the user db. but change the behavior when update or insert user info to db.For example, I have pre-existed website, so when user register on wp ,I can load it from my exist system to wp ,and even change the insert ID according to old system.

[fatihwk]

filter is ok. but can it change the progress of saving user to db? I just want user to control how to "SAVE" data to db,no matter it's update or insert.

[chriscct7]

No new requests for this in 2 years, and I can't see a compelling case for core needing to add this.