Wikimedia Bugzilla is closed!

I thought i had put up a bug about this somewhere, including a patch, but i
might have been on sf...

The use of pack in Math.php breaks because PostgreSQL, quite correctly,
validates it's utf8 input. Once upon a time i had a proper patch for this, but
now i only have a 1.9.2 diff against 1.9.3...

Anyways, to give a understanding of the changes that should be made:
@@ -153,9 +152,9 @@
 
                        # Now save it back to the DB:
                        if ( !wfReadOnly() ) {
-                               $outmd5_sql = $this->hash;
+                               $outmd5_sql = pack('H32', $this->hash);
 
-                               $md5_sql = $this->md5;
+                               $md5_sql = pack('H32', $this->md5); # Binary
packed, not hex
 
                                $dbw =& wfGetDB( DB_MASTER );
                                $dbw->replace( 'math', array( 'math_inputhash' ),
@@ -189,12 +188,13 @@
                $dbr =& wfGetDB( DB_SLAVE );
                $rpage = $dbr->selectRow( 'math',
                        array(
'math_outputhash','math_html_conservativeness','math_html','math_mathml' ),
-                       array( 'math_inputhash' => $this->md5), $fname
+                       array( 'math_inputhash' => pack("H32", $this->md5)), #
Binary packed, not hex
+                       $fname
                );
 
                if( $rpage !== false ) {
                        # Tailing 0x20s can get dropped by the database, add it
back on if necessary:
-                       $xhash = $rpage->math_outputhash;
+                       $xhash = unpack( 'H32md5', $rpage->math_outputhash . " 
              " );
                        $this->hash = $xhash ['md5'];
 
                        $this->conservativeness =
$rpage->math_html_conservativeness;

I do, however assume that $fname has been added since i changed my version...