Merge branch '3.4' into 4.2

* 3.4:
  Revert "bug #30423 [Security] Rework firewall's access denied rule (dimabory)"
  [FrameworkBundle] minor: remove a typo from changelog
  [VarDumper][Ldap] relax some locally failing tests
  [Validator] #30192 Added the missing translations for the Tagalog ("tl") locale.
  Make MimeTypeExtensionGuesser case insensitive

File/MimeType/MimeTypeExtensionGuesser.php

@@ -808,6 +808,12 @@ class MimeTypeExtensionGuesser implements ExtensionGuesserInterface
      */
     public function guess($mimeType)
     {
-        return isset($this->defaultExtensions[$mimeType]) ? $this->defaultExtensions[$mimeType] : null;
+        if (isset($this->defaultExtensions[$mimeType])) {
+            return $this->defaultExtensions[$mimeType];
+        }
+
+        $lcMimeType = strtolower($mimeType);
+
+        return isset($this->defaultExtensions[$lcMimeType]) ? $this->defaultExtensions[$lcMimeType] : null;
     }
 }

Tests/File/UploadedFileTest.php

@@ -94,6 +94,18 @@ public function testGuessClientExtensionWithIncorrectMimeType()
         $this->assertEquals('jpeg', $file->guessClientExtension());
     }
 
+    public function testCaseSensitiveMimeType()
+    {
+        $file = new UploadedFile(
+            __DIR__.'/Fixtures/case-sensitive-mime-type.xlsm',
+            'test.xlsm',
+            'application/vnd.ms-excel.sheet.macroEnabled.12',
+            null
+        );
+
+        $this->assertEquals('xlsm', $file->guessClientExtension());
+    }
+
     public function testErrorIsOkByDefault()
     {
         $file = new UploadedFile(