wp-admin/includes/media.php:2089Outputs the legacy media upload header.
function media_upload_header() { $post_id = isset( $_REQUEST['post_id'] ) ? (int) $_REQUEST['post_id'] : 0; echo '<script>post_id = ' . $post_id . ';</script>'; if ( empty( $_GET['chromeless'] ) ) { echo '<div id="media-upload-header">'; the_media_upload_tabs(); echo '</div>'; }}Introduced in 2.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-admin/includes/media.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.