PHP notice messages

I’m seeing this PHP notice message on every page when WP_DEBUG is enabled:

Notice: Undefined variable: keywords in C:\[path-here]\plugins\wordpress-meta-keywords\wordpress-meta-keywords.php on line 50

Affected code:

if ( !empty($tags) ) {
			foreach ($tags as $tag) {
				$keywords[count($keywords)] = $tag->name;
			}
			echo '<meta name="keywords" content="'.implode(", ", $keywords).'" />'."\n";
		}

Suggested fix: Initialize the $keywords variable.

if ( !empty($tags) ) {
			$keywords=array();
			foreach ($tags as $tag) {
				$keywords[count($keywords)] = $tag->name;
			}
			echo '<meta name="keywords" content="'.implode(", ", $keywords).'" />'."\n";
		}

http://wordpress.org/plugins/wordpress-meta-keywords/