minor symfony#60233 [String] ignore the current locale before transliterating ASCII codes with iconv() (xabbuh)

This PR was merged into the 6.4 branch.

Discussion
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[String] ignore the current locale before transliterating ASCII codes with iconv()

| Q             | A
| ------------- | ---
| Branch?       | 6.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Issues        |
| License       | MIT

see https://github.com/symfony/symfony/actions/runs/14509713498/job/40705561464?pr=58370#step:9:1891

Commits
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d304d5d ignore the current locale before transliterating ASCII codes with iconv()

Author: nicolas-grekas

src/Symfony/Component/String/AbstractUnicodeString.php

@@ -135,15 +135,21 @@ public function ascii(array $rules = []): self
             } elseif (!\function_exists('iconv')) {
                 $s = preg_replace('/[^\x00-\x7F]/u', '?', $s);
             } else {
-                $s = @preg_replace_callback('/[^\x00-\x7F]/u', static function ($c) {
-                    $c = (string) iconv('UTF-8', 'ASCII//TRANSLIT', $c[0]);
-
-                    if ('' === $c && '' === iconv('UTF-8', 'ASCII//TRANSLIT', '²')) {
-                        throw new \LogicException(sprintf('"%s" requires a translit-able iconv implementation, try installing "gnu-libiconv" if you\'re using Alpine Linux.', static::class));
-                    }
+                $previousLocale = setlocale(\LC_CTYPE, 0);
+                try {
+                    setlocale(\LC_CTYPE, 'C');
+                    $s = @preg_replace_callback('/[^\x00-\x7F]/u', static function ($c) {
+                        $c = (string) iconv('UTF-8', 'ASCII//TRANSLIT', $c[0]);
+
+                        if ('' === $c && '' === iconv('UTF-8', 'ASCII//TRANSLIT', '²')) {
+                            throw new \LogicException(sprintf('"%s" requires a translit-able iconv implementation, try installing "gnu-libiconv" if you\'re using Alpine Linux.', static::class));
+                        }
 
-                    return 1 < \strlen($c) ? ltrim($c, '\'`"^~') : ('' !== $c ? $c : '?');
-                }, $s);
+                        return 1 < \strlen($c) ? ltrim($c, '\'`"^~') : ('' !== $c ? $c : '?');
+                    }, $s);
+                } finally {
+                    setlocale(\LC_CTYPE, $previousLocale);
+                }
             }
         }
 

src/Symfony/Component/String/Tests/Slugger/AsciiSluggerTest.php

@@ -106,4 +106,19 @@ public static function provideSlugEmojiTests(): iterable
             'undefined_locale', // Behaves the same as if emoji support is disabled
         ];
     }
+
+    /**
+     * @requires extension intl
+     */
+    public function testSlugEmojiWithSetLocale()
+    {
+        if (!setlocale(LC_ALL, 'C.UTF-8')) {
+            $this->markTestSkipped('Unable to switch to the "C.UTF-8" locale.');
+        }
+
+        $slugger = new AsciiSlugger();
+        $slugger = $slugger->withEmoji(true);
+
+        $this->assertSame('a-and-a-go-to', (string) $slugger->slug('a 😺, 🐈‍⬛, and a 🦁 go to 🏞️... 😍 🎉 💛', '-'));
+    }
 }