Use PDO::ATTR_CLIENT_VERSION when PDO::ATTR_DRIVER_VERSION does not exist (#7564)

program/lib/Roundcube/db/sqlsrv.php

@@ -42,7 +42,18 @@ class rcube_db_sqlsrv extends rcube_db_mssql
         }
 
         if ($table) {
-            $driver_version = $this->dbh->getAttribute(PDO::ATTR_DRIVER_VERSION);
+            // For some unknown reason the constant described in the driver docs
+            // might not exist, we'll fallback to PDO::ATTR_CLIENT_VERSION (#7564)
+            if (defined('PDO::ATTR_DRIVER_VERSION')) {
+                $driver_version = $this->dbh->getAttribute(PDO::ATTR_DRIVER_VERSION);
+            }
+            else if (defined('PDO::ATTR_CLIENT_VERSION')) {
+                $client_version = $this->dbh->getAttribute(PDO::ATTR_CLIENT_VERSION);
+                $driver_version = $client_version['ExtensionVer'];
+            }
+            else {
+                $driver_version = 5;
+            }
 
             // Starting from version 5 of the driver lastInsertId() method expects
             // a sequence name instead of a table name. We'll unset the argument