fix: avoid "No clang found" when the clang cache is deleted by a parallel request

redaxo/src/core/lib/clang/clang.php

@@ -243,10 +243,14 @@ private static function checkCache()
         }
 
         $file = rex_path::coreCache('clang.cache');
-        if (!is_file($file)) {
-            rex_clang_service::generateCache();
+        $cache = rex_file::getCache($file);
+
+        // deliberately no is_file() check: a parallel cache clear could delete the file between check and read
+        if (!$cache) {
+            $cache = rex_clang_service::generateCache();
         }
-        foreach (rex_file::getCache($file) as $id => $data) {
+
+        foreach ($cache as $id => $data) {
             $clang = new self();
             $clang->id = (int) $id;
             $clang->priority = (int) $data['priority'];

redaxo/src/core/lib/clang/service.php

@@ -127,7 +127,7 @@ public static function deleteCLang($id)
      * Schreibt Spracheigenschaften in die Datei include/clang.php.
      *
      * @throws rex_exception
-     * @return void
+     * @return array<int, array<string, scalar|null>>
      */
     public static function generateCache()
     {
@@ -146,5 +146,7 @@ public static function generateCache()
         if (!rex_file::putCache($file, $clangs)) {
             throw new rex_exception('Clang cache file could not be generated');
         }
+
+        return $clangs;
     }
 }