[Intl] fix #39100

AmirHo3ein13 · AmirHo3ein13 · commit 7433519d6d82 · 2021-02-14T21:33:26.000+03:30
locale_parse returns null if `$locale` length is greater than `INTL_MAX_LOCALE_LEN`.
throw InvalidArgumentException if $locale length is greater than INTL_MAX_LOCALE_LEN.
diff --git a/src/Symfony/Component/Intl/Locale.php b/src/Symfony/Component/Intl/Locale.php
@@ -68,7 +68,14 @@ public static function getDefaultFallback(): ?string
     public static function getFallback(string $locale): ?string
     {
         if (\function_exists('locale_parse')) {
-            $localeSubTags = locale_parse($locale);
+            if (null === $localeSubTags = locale_parse($locale)) {
+                if (\defined('INTL_MAX_LOCALE_LEN')) {
+                    $message = sprintf('The length of $locale must be less than %s', INTL_MAX_LOCALE_LEN);
+                }
+
+                throw new \InvalidArgumentException($message ?? '');
+            }
+
             if (1 === \count($localeSubTags)) {
                 if ('root' !== self::$defaultFallback && self::$defaultFallback === $localeSubTags['language']) {
                     return 'root';
