From beta hhvm logs:
Notice: Undefined index: 0 in /srv/mediawiki/php-master/extensions/Echo/includes/DiscussionParser.php on line 873
The code
// Step 2: Generalise it // Trim off the timezone to replace at the end $output = $exemplarTimestamp; $tzRegex = '/\s*\(\w+\)\s*$/'; $tzMatches = array(); preg_match( $tzRegex, $output, $tzMatches ); $output = preg_replace( $tzRegex, '', $output ); $output = preg_quote( $output, '/' ); $output = preg_replace( '/[^\d\W]+/u', '[^\d\W]+', $output ); $output = preg_replace( '/\d+/u', '\d+', $output ); $output .= preg_quote( $tzMatches[0] );
never checks to see if $tzRegex actually matched anything.