[9.x] Back porting #47838 (#47840)

* Retain $request->request InputBag type

* Assert content

Author: timacdonald

src/Illuminate/Http/Request.php

@@ -11,6 +11,7 @@
 use Illuminate\Support\Traits\Macroable;
 use RuntimeException;
 use Symfony\Component\HttpFoundation\Exception\SessionNotFoundException;
+use Symfony\Component\HttpFoundation\InputBag;
 use Symfony\Component\HttpFoundation\ParameterBag;
 use Symfony\Component\HttpFoundation\Request as SymfonyRequest;
 use Symfony\Component\HttpFoundation\Session\SessionInterface;
@@ -487,7 +488,7 @@ public static function createFromBase(SymfonyRequest $request)
         $newRequest->content = $request->content;
 
         if ($newRequest->isJson()) {
-            $newRequest->request = $newRequest->json();
+            $newRequest->request = new InputBag($newRequest->json()->all());
         }
 
         return $newRequest;

tests/Http/HttpRequestTest.php

@@ -16,6 +16,7 @@
 use RuntimeException;
 use Symfony\Component\HttpFoundation\Exception\SessionNotFoundException;
 use Symfony\Component\HttpFoundation\File\UploadedFile as SymfonyUploadedFile;
+use Symfony\Component\HttpFoundation\InputBag;
 use Symfony\Component\HttpFoundation\Request as SymfonyRequest;
 use Symfony\Component\HttpFoundation\Session\SessionInterface;
 
@@ -1559,4 +1560,18 @@ public function testHttpRequestFlashExceptCallsFlashWithProperParameters()
         $request->setLaravelSession($session);
         $request->flashExcept(['email']);
     }
+
+    public function testGeneratingJsonRequestFromParentRequestUsesCorrectType()
+    {
+        if (! method_exists(SymfonyRequest::class, 'getPayload')) {
+            return;
+        }
+
+        $base = SymfonyRequest::create('/', 'POST', server: ['CONTENT_TYPE' => 'application/json'], content: '{"hello":"world"}');
+
+        $request = Request::createFromBase($base);
+
+        $this->assertInstanceOf(InputBag::class, $request->getPayload());
+        $this->assertSame('world', $request->getPayload()->get('hello'));
+    }
 }