Merge branch 'fix/#2428-sql-server-2012-newline-before-order-by-2.5' into 2.5

Close #2428

lib/Doctrine/DBAL/Platforms/SQLServer2012Platform.php

@@ -102,4 +102,57 @@ class SQLServer2012Platform extends SQLServer2008Platform
     {
         return 'Doctrine\DBAL\Platforms\Keywords\SQLServer2012Keywords';
     }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function doModifyLimitQuery($query, $limit, $offset = null)
+    {
+        if ($limit === null && $offset === null) {
+            return $query;
+        }
+
+        // Queries using OFFSET... FETCH MUST have an ORDER BY clause
+        // Find the position of the last instance of ORDER BY and ensure it is not within a parenthetical statement
+        // but can be in a newline
+        $matches      = array();
+        $matchesCount = preg_match_all("/[\\s]+order by /i", $query, $matches, PREG_OFFSET_CAPTURE);
+        $orderByPos   = false;
+
+        if ($matchesCount > 0) {
+            $orderByPos = $matches[0][($matchesCount - 1)][1];
+        }
+        
+        if ($orderByPos === false
+            || substr_count($query, "(", $orderByPos) - substr_count($query, ")", $orderByPos)
+        ) {
+            if (stripos($query, 'SELECT DISTINCT') === 0) {
+                // SQL Server won't let us order by a non-selected column in a DISTINCT query,
+                // so we have to do this madness. This says, order by the first column in the
+                // result. SQL Server's docs say that a nonordered query's result order is non-
+                // deterministic anyway, so this won't do anything that a bunch of update and
+                // deletes to the table wouldn't do anyway.
+                $query .= " ORDER BY 1";
+            } else {
+                // In another DBMS, we could do ORDER BY 0, but SQL Server gets angry if you
+                // use constant expressions in the order by list.
+                $query .= " ORDER BY (SELECT 0)";
+            }
+        }
+
+        if ($offset === null) {
+            $offset = 0;
+        }
+
+        // This looks somewhat like MYSQL, but limit/offset are in inverse positions
+        // Supposedly SQL:2008 core standard.
+        // Per TSQL spec, FETCH NEXT n ROWS ONLY is not valid without OFFSET n ROWS.
+        $query .= " OFFSET " . (int) $offset . " ROWS";
+
+        if ($limit !== null) {
+            $query .= " FETCH NEXT " . (int) $limit . " ROWS ONLY";
+        }
+
+        return $query;
+    }
 }