Merge branch '5.4' into 6.3

* 5.4:
  [Config] Prefixing FileExistenceResource::__toString() to avoid conflict with FileResource
  [String] Method toByteString conversion using iconv is unreachable
  [HttpKernel] Fix PHP deprecation

Author: nicolas-grekas

AbstractString.php

@@ -512,8 +512,11 @@ public function toByteString(string $toEncoding = null): ByteString
         try {
             try {
                 $b->string = mb_convert_encoding($this->string, $toEncoding, 'UTF-8');
-            } catch (InvalidArgumentException $e) {
+            } catch (InvalidArgumentException|\ValueError $e) {
                 if (!\function_exists('iconv')) {
+                    if ($e instanceof \ValueError) {
+                        throw new InvalidArgumentException($e->getMessage(), $e->getCode(), $e);
+                    }
                     throw $e;
                 }
 

Tests/AbstractAsciiTestCase.php

@@ -1581,4 +1581,22 @@ public static function provideWidth(): array
             [17, "\u{007f}\u{007f}f\u{001b}[0moo\u{0001}bar\u{007f}cccïf\u{008e}cy\u{0005}1", false], // f[0moobarcccïfcy1
         ];
     }
+
+    /**
+     * @dataProvider provideToByteString
+     */
+    public function testToByteString(string $origin, string $encoding)
+    {
+        $instance = static::createFromString($origin)->toByteString($encoding);
+        $this->assertInstanceOf(ByteString::class, $instance);
+    }
+
+    public static function provideToByteString(): array
+    {
+        return [
+            ['žsžsý', 'UTF-8'],
+            ['žsžsý', 'windows-1250'],
+            ['žsžsý', 'Windows-1252'],
+        ];
+    }
 }