database checks in init.php

init.php

@@ -29,12 +29,17 @@
 }
 // Start database connection
 // Depending on the DB driver, instantiate a PDO object with the necessary credentials.
+$db_drivers = PDO::getAvailableDrivers();
+if (!in_array($db_driver,$db_drivers)){
+	die('Requested to use '.$db_driver.', which is not enabled!');
+}
 switch ($db_driver) {
     case "mysql":
-        if (!empty($db_name) and !empty($db_user)) {
-            $conn = new PDO("mysql:host=$db_host;dbname=$db_name;charset=utf8", $db_user, $db_pass);
-            break;
-        }
+        if (empty($db_name) or empty($db_user)){
+            die('You must set $db_name and $db_user in /config/'.CL_CONFIG . '/config.php to use mysql, or set $db_driver to "sqlite" to use an SQLite database!');
+        } 
+        $conn = new PDO("mysql:host=$db_host;dbname=$db_name;charset=utf8", $db_user, $db_pass);
+        break;
     case "sqlite":
         $conn = new PDO("sqlite:" . CL_ROOT . "/files/collabtive.sdb");
         break;