Share the same uploads dir for a BuddyPress multiblog set up

## bp-custom.php
<?php
/**
 * Multiblog must have been set for it to work :)
 *
 * eg: define( 'BP_ENABLE_MULTIBLOG', true );
 */

function rbaccaro_set_multiblog_shared_upload_dir() {
  if ( ! bp_is_multiblog_mode() ) {
    return;
  }

  $current_site = get_current_site();

  if ( (int) bp_get_root_blog_id() !== (int) $current_site->blog_id ) {
    $switched = true;
    switch_to_blog( $current_site->blog_id );
  }

  buddypress()->upload_dir = wp_upload_dir();

  if ( ! empty( $switched ) ) {
    restore_current_blog();
  }
}
add_action( 'bp_init', 'rbaccaro_set_multiblog_shared_upload_dir', 1 );