Fix #3082: Add BC for PDO-only fetch modes

lib/Doctrine/DBAL/Driver/PDOStatement.php

@@ -22,6 +22,9 @@
 use Doctrine\DBAL\FetchMode;
 use Doctrine\DBAL\ParameterType;
 use PDO;
+use const E_USER_DEPRECATED;
+use function sprintf;
+use function trigger_error;
 
 /**
  * The PDO implementation of the Statement interface.
@@ -213,7 +216,13 @@ public function fetchColumn($columnIndex = 0)
     private function convertParamType(int $type) : int
     {
         if (! isset(self::PARAM_TYPE_MAP[$type])) {
-            throw new \InvalidArgumentException('Invalid parameter type: ' . $type);
+            // TODO: next major: throw an exception
+            @trigger_error(sprintf(
+                'Using a PDO parameter type (%d given) is deprecated and will cause an error in Doctrine 3.0',
+                $type
+            ), E_USER_DEPRECATED);
+
+            return $type;
         }
 
         return self::PARAM_TYPE_MAP[$type];
@@ -231,7 +240,14 @@ private function convertFetchMode(?int $fetchMode) : ?int
         }
 
         if (! isset(self::FETCH_MODE_MAP[$fetchMode])) {
-            throw new \InvalidArgumentException('Invalid fetch mode: ' . $fetchMode);
+            // TODO: next major: throw an exception
+            @trigger_error(sprintf(
+                'Using a PDO fetch mode or their combination (%d given)' .
+                ' is deprecated and will cause an error in Doctrine 3.0',
+                $fetchMode
+            ), E_USER_DEPRECATED);
+
+            return $fetchMode;
         }
 
         return self::FETCH_MODE_MAP[$fetchMode];

tests/Doctrine/Tests/DBAL/Functional/PDOStatementTest.php

@@ -0,0 +1,54 @@
+<?php
+
+namespace Doctrine\Tests\DBAL\Functional;
+
+use Doctrine\DBAL\Driver\PDOConnection;
+use Doctrine\DBAL\Schema\Table;
+use Doctrine\Tests\DbalFunctionalTestCase;
+use PDO;
+use function extension_loaded;
+
+class PDOStatementTest extends DbalFunctionalTestCase
+{
+    protected function setUp()
+    {
+        if (! extension_loaded('pdo')) {
+            $this->markTestSkipped('PDO is not installed');
+        }
+
+        parent::setUp();
+
+        if (! $this->_conn->getWrappedConnection() instanceof PDOConnection) {
+            $this->markTestSkipped('PDO-only test');
+        }
+
+        $table = new Table('stmt_test');
+        $table->addColumn('id', 'integer');
+        $table->addColumn('name', 'text');
+        $this->_conn->getSchemaManager()->dropAndCreateTable($table);
+    }
+
+    /**
+     * @group legacy
+     * @expectedDeprecation Using a PDO fetch mode or their combination (%d given) is deprecated and will cause an error in Doctrine 3.0
+     */
+    public function testPDOSpecificModeIsAccepted()
+    {
+        $this->_conn->insert('stmt_test', [
+            'id' => 1,
+            'name' => 'Alice',
+        ]);
+        $this->_conn->insert('stmt_test', [
+            'id' => 2,
+            'name' => 'Bob',
+        ]);
+
+        $data = $this->_conn->query('SELECT id, name FROM stmt_test ORDER BY id')
+            ->fetchAll(PDO::FETCH_KEY_PAIR);
+
+        self::assertSame([
+            1 => 'Alice',
+            2 => 'Bob',
+        ], $data);
+    }
+}