WordPress at a glance
filter is not described

pre_upload_error filter-hook . WP 2.1.0

Filters whether to preempt the XML-RPC media upload.

Passing a truthy value will effectively short-circuit the media upload, returning that value as a 500 error instead.

Usage

add_filter( 'pre_upload_error', 'filter_function_name_3580' );
function filter_function_name_3580( $error ){
	// filter...

	return $error;
}
$error(true/false)
Whether to pre-empt the media upload.
Default: false

Changelog

Since 2.1.0 Introduced.

Where the hook is called

wp_xmlrpc_server::mw_newMediaObject()
pre_upload_error
wp-includes/class-wp-xmlrpc-server.php 6344
$upload_err = apply_filters( 'pre_upload_error', false );

Where in WP core the hook is used

Usage not found!