db-error.php not used for all DB failures

[markjaquith]

db-error.php (the optional custom DB error message file to be placed in wp-content) does not get included all the time. Sometimes wp-db.php will use its bail() method to spit out its own message. This code needs to be there too:

        if ( file_exists( WP_CONTENT_DIR . '/db-error.php' ) ) {
                require_once( WP_CONTENT_DIR . '/db-error.php' );
                die();
        }

The purpose of the db-error.php was for prettying up the front-end database connection error screen, or giving some other form of feedback. It has never affected the back-end.

I'm not sure using it for the backend failure cases is a good idea, it'll mean that anyone currently using the file will have to modify it in order to see the DB errors.

Shifting to 3.1 pending patch & feedback from others..