A not existing hook function in a plugin will always cause a true return value to not break interrupt flow.

mfechner · mfechner · commit eb6a46eeca3e · 2015-03-24T10:51:12.000+01:00
diff --git a/library/ViMbAdmin/Plugin.php b/library/ViMbAdmin/Plugin.php
@@ -70,6 +70,7 @@ public function update( $controller, $action, $hook, OSS_Controller_Action $cont
         $hookfn = "{$controller}_{$action}_{$hook}";
         if( method_exists( $this, $hookfn ) )
             return $this->$hookfn( $controllerObject, $params );
+        return true;
     }
 
 

Original file line number	Diff line number	Diff line change
`@@ -70,6 +70,7 @@ public function update( $controller, $action, $hook, OSS_Controller_Action $cont`
`70`	`70`	`$hookfn = "{$controller}_{$action}_{$hook}";`
`71`	`71`	`if( method_exists( $this, $hookfn ) )`
`72`	`72`	`return $this->$hookfn( $controllerObject, $params );`
	`73`	`+ return true;`
`73`	`74`	`}`
`74`	`75`
`75`	`76`