php merge and override arrays recursively

gistfile1.txt

<?php 
/**
 * Merge given arrays, overriding $defaults array with values from $args array recursively.
 *
 * @author ckchaudahry
 *
 * @param $args array
 * @param $defaults array
 *
 * @return array
 */
function wdw_merge_array_recursively( $args, $defaults ) {
	$merged = array();
	//first all values from args
	foreach( $args as $arg_key=>$arg_val ){
		if( is_array( $arg_val ) && array_key_exists( $arg_key, $defaults ) ){
			$merged[$arg_key] = wdw_merge_array_recursively( $arg_val, $defaults[$arg_key] );
		} else {
			if( empty( $arg_val ) && isset( $defaults[$arg_key] ) ){
				$merged[$arg_key] = $defaults[$arg_key];
			} else {
				$merged[$arg_key] = $arg_val;
			}
		}
	}

	//then all values from defaults
	foreach ( $defaults as $def_key=>$def_val ) {
		if ( !array_key_exists( $def_key, $merged ) ) {
			$merged[$def_key] = $def_val;
		}
	}

	return $merged;
}
?>