From 0ec46e17cc970bc8332b2aa268ba1b41fbc948e6 Mon Sep 17 00:00:00 2001
From: Nicolas Grekas <nicolas.grekas@gmail.com>
Date: Mon, 25 Nov 2019 23:08:33 +0100
Subject: [PATCH] Default to real-utf8 when no charset is provided

---
 ConnectionFactory.php           | 15 +++++++++++++++
 Tests/ConnectionFactoryTest.php | 20 ++++++++++++++++++++
 UPGRADE-2.0.md                  |  2 ++
 3 files changed, 37 insertions(+)

diff --git a/ConnectionFactory.php b/ConnectionFactory.php
index 4fb04b2e6..08e96d0aa 100644
--- a/ConnectionFactory.php
+++ b/ConnectionFactory.php
@@ -6,6 +6,7 @@
 use Doctrine\DBAL\Configuration;
 use Doctrine\DBAL\Connection;
 use Doctrine\DBAL\DBALException;
+use Doctrine\DBAL\Driver\AbstractMySQLDriver;
 use Doctrine\DBAL\DriverManager;
 use Doctrine\DBAL\Exception\DriverException;
 use Doctrine\DBAL\Platforms\AbstractPlatform;
@@ -43,6 +44,20 @@ public function createConnection(array $params, Configuration $config = null, Ev
 
         $connection = DriverManager::getConnection($params, $config, $eventManager);
 
+        if (!isset($params['pdo']) && !isset($params['charset'])) {
+            $params = $connection->getParams();
+            $params['charset'] = 'utf8';
+            $driver = $connection->getDriver();
+
+            if ($driver instanceof AbstractMySQLDriver) {
+                $params['charset'] = 'utf8mb4';
+                $params['defaultTableOptions']['collate'] = $params['defaultTableOptions']['collate'] ?? 'utf8mb4_unicode_ci';
+            }
+
+            $connectionClass = \get_class($connection);
+            $connection = new $connectionClass($params, $driver, $connection->getConfiguration(), $connection->getEventManager());
+        }
+
         if (! empty($mappingTypes)) {
             $platform = $this->getDatabasePlatform($connection);
             foreach ($mappingTypes as $dbType => $doctrineType) {
diff --git a/Tests/ConnectionFactoryTest.php b/Tests/ConnectionFactoryTest.php
index d82bed875..7cbe6a5a5 100644
--- a/Tests/ConnectionFactoryTest.php
+++ b/Tests/ConnectionFactoryTest.php
@@ -49,6 +49,26 @@ public function testContainer()
             FakeDriver::$exception = null;
         }
     }
+
+    public function testDefaultCharset()
+    {
+        $factory = new ConnectionFactory([]);
+        $params = ['driverClass' => FakeDriver::class];
+
+        $connection = $factory->createConnection($params);
+
+        $this->assertSame('utf8', $connection->getParams()['charset']);
+    }
+
+    public function testDefaultCharsetMySql()
+    {
+        $factory = new ConnectionFactory([]);
+        $params = ['driver' => 'pdo_mysql'];
+
+        $connection = $factory->createConnection($params);
+
+        $this->assertSame('utf8mb4', $connection->getParams()['charset']);
+    }
 }
 
 /**
diff --git a/UPGRADE-2.0.md b/UPGRADE-2.0.md
index 1ca22a062..82aee80a0 100644
--- a/UPGRADE-2.0.md
+++ b/UPGRADE-2.0.md
@@ -9,6 +9,8 @@ PHP and Symfony version support
    Symfony 3.4 LTS and 4.1 or newer.
  * Support for Twig 1.34 and below as well as 2.4 and below (for 2.x) releases
    was dropped.
+ * When no charset parameter is defined, it now defaults to `utf8mb4` on the
+   MySQL platform and to `utf8` on all other platforms.
 
 Commands
 --------