filter_api.zip [^] (20,402 bytes) 06-09-06 09:36 is wrong!!!
please check this one
[new]filter_api.zip [^] (20,475 bytes) 06-09-06 10:22

now, bug filter run correctly with oracle (driver oci8)

function for this file database_api.php

function empty_string( $p_field,$p_bool){
$t_db_type = config_get( 'db_type' );

    switch( $t_db_type ) {
        case 'mssql':
        case 'odbc_mssql':
        case 'mysql':
        case 'mysqli':
        case 'postgres':
        case 'postgres64':
        case 'postgres7':
        case 'pgsql':
        if ($p_bool)
        return "$p_field=''";
        else
        return "$p_field!=''";
        case 'oci8':
        if ($p_bool)
        return "$p_field IS NULL";
        else
        return "$p_field IS NOT NULL";

        default:
            error_parameters( 'db_type', $t_db_type );
            trigger_error( ERROR_CONFIG_OPT_INVALID, ERROR );
}
}

and for exemple in the file filer_api.php

$query = "SELECT id FROM $t_filters_table
WHERE user_id='$t_user_id'
AND project_id='$c_project_id'
AND ".empty_string('name',true);

Or
$query = "SELECT * FROM $t_filters_table
WHERE (project_id='$t_project_id'
OR project_id='0')
AND ".empty_string('name',false)."
ORDER BY is_public DESC, name ASC";

Would you have a chance to test if problem still exists using oracle branch in 0013227 (https://github.com/dregad/mantisbt/commits/oracle), and submit a revised patch/pull request against that if it's the case ?