Merge branch '4.4' into 5.2

* 4.4:
  [HttpFoundation] Fix return types of SessionHandler::gc()
  [Cache] Support decorated Dbal drivers in PdoAdapter
  [VarDumper] Support for intersection types

Author: nicolas-grekas

Session/Storage/Handler/MemcachedSessionHandler.php

@@ -99,12 +99,13 @@ protected function doDestroy(string $sessionId)
     }
 
     /**
-     * @return bool
+     * @return int|false
      */
+    #[\ReturnTypeWillChange]
     public function gc($maxlifetime)
     {
         // not required here because memcached will auto expire the records anyhow.
-        return true;
+        return 0;
     }
 
     /**

Session/Storage/Handler/MigratingSessionHandler.php

@@ -63,7 +63,7 @@ public function destroy($sessionId)
     }
 
     /**
-     * @return bool
+     * @return int|false
      */
     #[\ReturnTypeWillChange]
     public function gc($maxlifetime)

Session/Storage/Handler/MongoDbSessionHandler.php

@@ -100,15 +100,14 @@ protected function doDestroy(string $sessionId)
     }
 
     /**
-     * @return bool
+     * @return int|false
      */
+    #[\ReturnTypeWillChange]
     public function gc($maxlifetime)
     {
-        $this->getCollection()->deleteMany([
+        return $this->getCollection()->deleteMany([
             $this->options['expiry_field'] => ['$lt' => new \MongoDB\BSON\UTCDateTime()],
-        ]);
-
-        return true;
+        ])->getDeletedCount();
     }
 
     /**

Session/Storage/Handler/NullSessionHandler.php

@@ -70,11 +70,11 @@ protected function doDestroy(string $sessionId)
     }
 
     /**
-     * @return bool
+     * @return int|false
      */
     #[\ReturnTypeWillChange]
     public function gc($maxlifetime)
     {
-        return true;
+        return 0;
     }
 }

Session/Storage/Handler/PdoSessionHandler.php

@@ -290,7 +290,7 @@ public function read($sessionId)
     }
 
     /**
-     * @return bool
+     * @return int|false
      */
     #[\ReturnTypeWillChange]
     public function gc($maxlifetime)
@@ -299,7 +299,7 @@ public function gc($maxlifetime)
         // This way, pruning expired sessions does not block them from being started while the current session is used.
         $this->gcCalled = true;
 
-        return true;
+        return 0;
     }
 
     /**

Session/Storage/Handler/RedisSessionHandler.php

@@ -116,10 +116,13 @@ public function close(): bool
 
     /**
      * {@inheritdoc}
+     *
+     * @return int|false
      */
-    public function gc($maxlifetime): bool
+    #[\ReturnTypeWillChange]
+    public function gc($maxlifetime)
     {
-        return true;
+        return 0;
     }
 
     /**

Tests/Session/Storage/Handler/AbstractRedisSessionHandlerTestCase.php

@@ -114,7 +114,7 @@ public function testDestroySession()
 
     public function testGcSession()
     {
-        $this->assertTrue($this->storage->gc(123));
+        $this->assertIsInt($this->storage->gc(123));
     }
 
     public function testUpdateTimestamp()

Tests/Session/Storage/Handler/Fixtures/common.inc

@@ -121,11 +121,12 @@ class TestSessionHandler extends AbstractSessionHandler
         return true;
     }
 
-    public function gc($maxLifetime): bool
+    #[\ReturnTypeWillChange]
+    public function gc($maxLifetime)
     {
         echo __FUNCTION__, "\n";
 
-        return true;
+        return 1;
     }
 
     protected function doRead($sessionId): string

Tests/Session/Storage/Handler/MemcachedSessionHandlerTest.php

@@ -113,7 +113,7 @@ public function testDestroySession()
 
     public function testGcSession()
     {
-        $this->assertTrue($this->storage->gc(123));
+        $this->assertIsInt($this->storage->gc(123));
     }
 
     /**

Tests/Session/Storage/Handler/MongoDbSessionHandlerTest.php

@@ -184,9 +184,14 @@ public function testGc()
             ->willReturnCallback(function ($criteria) {
                 $this->assertInstanceOf(\MongoDB\BSON\UTCDateTime::class, $criteria[$this->options['expiry_field']]['$lt']);
                 $this->assertGreaterThanOrEqual(time() - 1, round((string) $criteria[$this->options['expiry_field']]['$lt'] / 1000));
+
+                $result = $this->createMock(\MongoDB\DeleteResult::class);
+                $result->method('getDeletedCount')->willReturn(42);
+
+                return $result;
             });
 
-        $this->assertTrue($this->storage->gc(1));
+        $this->assertSame(42, $this->storage->gc(1));
     }
 
     public function testGetConnection()