Merge branch '5.4' into 6.3

* 5.4:
  [Translation] Fix `TranslationNodeVisitor` with constant domain
  [Messenger] [AMQP] Throw exception on `nack` callback
  [Validator] revise Latvian translations
  [ErrorHandler] Fix `RecursiveDirectoryIterator` exception with wrong composer autoload
  [HttpFoundation] Request without content-type or content-length header should result in null values, not empty strings
  [Cache] Fix possible infinite loop in `CachePoolPass`
  [Mime] Fix undefined array key 0 when empty sender
  [Console] Allow '0' as a $shortcut in InputOption.php
  fix multi-byte code area to convert
  [Validator] Make it explicit when English translation differs from its resource name

Input/InputOption.php

@@ -75,7 +75,7 @@ public function __construct(string $name, string|array $shortcut = null, int $mo
             throw new InvalidArgumentException('An option name cannot be empty.');
         }
 
-        if (empty($shortcut)) {
+        if ('' === $shortcut || [] === $shortcut) {
             $shortcut = null;
         }
 
@@ -84,10 +84,10 @@ public function __construct(string $name, string|array $shortcut = null, int $mo
                 $shortcut = implode('|', $shortcut);
             }
             $shortcuts = preg_split('{(\|)-?}', ltrim($shortcut, '-'));
-            $shortcuts = array_filter($shortcuts);
+            $shortcuts = array_filter($shortcuts, 'strlen');
             $shortcut = implode('|', $shortcuts);
 
-            if (empty($shortcut)) {
+            if ('' === $shortcut) {
                 throw new InvalidArgumentException('An option shortcut cannot be empty.');
             }
         }

Tests/Input/InputOptionTest.php

@@ -59,6 +59,20 @@ public function testShortcut()
         $this->assertEquals('f|ff|fff', $option->getShortcut(), '__construct() removes the leading - of the shortcuts');
         $option = new InputOption('foo');
         $this->assertNull($option->getShortcut(), '__construct() makes the shortcut null by default');
+        $option = new InputOption('foo', '');
+        $this->assertNull($option->getShortcut(), '__construct() makes the shortcut null when given an empty string');
+        $option = new InputOption('foo', []);
+        $this->assertNull($option->getShortcut(), '__construct() makes the shortcut null when given an empty array');
+        $option = new InputOption('foo', ['f', '', 'fff']);
+        $this->assertEquals('f|fff', $option->getShortcut(), '__construct() removes empty shortcuts');
+        $option = new InputOption('foo', 'f||fff');
+        $this->assertEquals('f|fff', $option->getShortcut(), '__construct() removes empty shortcuts');
+        $option = new InputOption('foo', '0');
+        $this->assertEquals('0', $option->getShortcut(), '-0 is an acceptable shortcut value');
+        $option = new InputOption('foo', ['0', 'z']);
+        $this->assertEquals('0|z', $option->getShortcut(), '-0 is an acceptable shortcut value when embedded in an array');
+        $option = new InputOption('foo', '0|z');
+        $this->assertEquals('0|z', $option->getShortcut(), '-0 is an acceptable shortcut value when embedded in a string-list');
     }
 
     public function testModes()