Merge branch '4.4'

* 4.4:
  cs fix
  Fix inconsistent return points.
  [Config] Add handling for ignored keys in ArrayNode::mergeValues.
  Fix inconsistent return points.
  [Security/Core] UserInterface::getPassword() can return null
  cs fix
  cs fix
  Fix missing exporter in PHPUnit constraint poylfill
  added `Process::getLastOutputTime()` method
  [Router] Fix TraceableUrlMatcher behaviour with trailing slash
  [HttpKernel] Remove outdated docblock comment
  Fix handling for session parameters
  Revert "bug #33092 [DependencyInjection] Improve an exception message (fabpot)"

Author: nicolas-grekas

Parser/Tokenizer/TokenizerEscaping.php

@@ -58,6 +58,8 @@ private function replaceUnicodeSequences(string $value): string
             if (0x10000 > $c) {
                 return \chr(0xE0 | $c >> 12).\chr(0x80 | $c >> 6 & 0x3F).\chr(0x80 | $c & 0x3F);
             }
+
+            return '';
         }, $value);
     }
 }

XPath/Translator.php

@@ -114,6 +114,9 @@ public function selectorToXPath(SelectorNode $selector, string $prefix = 'descen
         return ($prefix ?: '').$this->nodeToXPath($selector);
     }
 
+    /**
+     * @return $this
+     */
     public function registerExtension(Extension\ExtensionInterface $extension): self
     {
         $this->extensions[$extension->getName()] = $extension;
@@ -139,6 +142,9 @@ public function getExtension(string $name): Extension\ExtensionInterface
         return $this->extensions[$name];
     }
 
+    /**
+     * @return $this
+     */
     public function registerParserShortcut(ParserInterface $shortcut): self
     {
         $this->shortcutParsers[] = $shortcut;