$header = unpack( 'Vofp/Vcsize', substr( $diff, 0, 8 ) );
# Check the checksum if mhash is available
- if ( function_exists( 'mhash' ) ) {
+ if ( extension_loaded( 'mhash' ) ) {
$ofp = mhash( MHASH_ADLER32, $base );
if ( $ofp !== substr( $diff, 0, 4 ) ) {
wfDebug( __METHOD__. ": incorrect base checksum\n" );