Fix #20532: Add missing return statements in CacheController::actionFlushSchema, FixtureController::actionUnload, HelpController::actionIndex and ServeController::actionIndex

framework/console/controllers/CacheController.php

@@ -169,6 +169,8 @@ class CacheController extends Controller
         } catch (\Exception $e) {
             $this->stdout($e->getMessage() . "\n\n", Console::FG_RED);
         }
+
+        return ExitCode::OK;
     }
 
     /**

framework/console/controllers/FixtureController.php

@@ -232,6 +232,8 @@ class FixtureController extends Controller
 
         $this->unloadFixtures($this->createFixtures($fixtures));
         $this->notifyUnloaded($fixtures);
+
+        return ExitCode::OK;
     }
 
     /**

framework/console/controllers/HelpController.php

@@ -11,6 +11,7 @@ use Yii;
 use yii\base\Application;
 use yii\console\Controller;
 use yii\console\Exception;
+use yii\console\ExitCode;
 use yii\helpers\Console;
 use yii\helpers\Inflector;
 
@@ -66,6 +67,8 @@ class HelpController extends Controller
         } else {
             $this->getDefaultHelp();
         }
+
+        return ExitCode::OK;
     }
 
     /**

framework/console/controllers/ServeController.php

@@ -9,6 +9,7 @@ namespace yii\console\controllers;
 
 use Yii;
 use yii\console\Controller;
+use yii\console\ExitCode;
 use yii\helpers\Console;
 
 /**
@@ -87,6 +88,8 @@ class ServeController extends Controller
         }
 
         $this->runCommand($command);
+
+        return ExitCode::OK;
     }
 
     /**