$parts = explode( '/', $subpage );
// Try to parse the values given, generating somewhat pretty URLs if possible
- if ( count( $parts ) === 1 ) {
+ if ( count( $parts ) === 1 && $parts[0] !== '' ) {
$this->mAddedRedirectParams['diff'] = $parts[0];
} elseif ( count( $parts ) === 2 ) {
$this->mAddedRedirectParams['oldid'] = $parts[0];
$this->mAddedRedirectParams['diff'] = $parts[1];
} else {
// Wrong number of parameters, bail out
+ $this->getOutput()->addHelpLink( 'Help:Diff' );
throw new ErrorPageError( 'nopagetitle', 'nopagetext' );
}