[9.x] Fix TrimStrings middleware with non-UTF8 characters (#42065)

* Fix TrimStrings middleware with non-UTF8 values

* Whitespace
This will trigger the tests again

Author: MrMicky-FR

src/Illuminate/Foundation/Http/Middleware/TrimStrings.php

@@ -49,11 +49,11 @@ public function handle($request, Closure $next)
      */
     protected function transform($key, $value)
     {
-        if (in_array($key, $this->except, true)) {
+        if (in_array($key, $this->except, true) || ! is_string($value)) {
             return $value;
         }
 
-        return is_string($value) ? preg_replace('~^[\s]+|[\s]+$~u', '', $value) : $value;
+        return preg_replace('~^[\s]+|[\s]+$~u', '', $value) ?? trim($value);
     }
 
     /**

tests/Foundation/Http/Middleware/TrimStringsTest.php

@@ -41,6 +41,7 @@ public function testTrimStringsNBSP()
             'foo' => 'ム',
             'bar' => '   だ    ',
             'baz' => '   ム    ',
+            'binary' => " \xE9  ",
         ]);
         $symfonyRequest->server->set('REQUEST_METHOD', 'GET');
         $request = Request::createFromBase($symfonyRequest);
@@ -52,6 +53,7 @@ public function testTrimStringsNBSP()
             $this->assertSame('ム', $request->get('foo'));
             $this->assertSame('だ', $request->get('bar'));
             $this->assertSame('ム', $request->get('baz'));
+            $this->assertSame("\xE9", $request->get('binary'));
         });
     }
 }