Merge branch '5.4' into 6.0

* 5.4:
  expand uninitialized session tests
  [Lock] Release PostgreSqlStore connection lock on failure
  [DomCrawler] Fix HTML5 parser charset option
  cs fix
  [HttpKernel] Do not attempt to register enum arguments in controller service locator
  [Mime] Fix missing sprintf in DkimSigner
  [Translation] [LocoProvider] Use rawurlencode and separate tag setting
  [Security] fix unserializing session payloads from v4
  [Cache] Don't lock when doing nested computations
  [Messenger] fix Redis support on 32b arch
  [HttpFoundation] Fix notice when HTTP_PHP_AUTH_USER passed without pass
  [Security] Add getting started example to README

Author: nicolas-grekas

ServerBag.php

@@ -87,7 +87,7 @@ public function getHeaders(): array
 
         // PHP_AUTH_USER/PHP_AUTH_PW
         if (isset($headers['PHP_AUTH_USER'])) {
-            $headers['AUTHORIZATION'] = 'Basic '.base64_encode($headers['PHP_AUTH_USER'].':'.$headers['PHP_AUTH_PW']);
+            $headers['AUTHORIZATION'] = 'Basic '.base64_encode($headers['PHP_AUTH_USER'].':'.($headers['PHP_AUTH_PW'] ?? ''));
         } elseif (isset($headers['PHP_AUTH_DIGEST'])) {
             $headers['AUTHORIZATION'] = $headers['PHP_AUTH_DIGEST'];
         }

Tests/ServerBagTest.php

@@ -57,6 +57,16 @@ public function testHttpPasswordIsOptional()
         ], $bag->getHeaders());
     }
 
+    public function testHttpPasswordIsOptionalWhenPassedWithHttpPrefix()
+    {
+        $bag = new ServerBag(['HTTP_PHP_AUTH_USER' => 'foo']);
+
+        $this->assertEquals([
+            'AUTHORIZATION' => 'Basic '.base64_encode('foo:'),
+            'PHP_AUTH_USER' => 'foo',
+        ], $bag->getHeaders());
+    }
+
     public function testHttpBasicAuthWithPhpCgi()
     {
         $bag = new ServerBag(['HTTP_AUTHORIZATION' => 'Basic '.base64_encode('foo:bar')]);