Bugfixes to help command

lib/Shell.php

@@ -113,8 +113,8 @@ class Shell
         }
         $context->setShell($this);
         $this->context = $context;
-        $context->onEnter();
         $this->dispatchEvent(self::EVT_CONTEXT_CHANGED);
+        $context->onEnter();
     }
 
     /**
@@ -429,12 +429,15 @@ class Shell
                     $_($command, $args,$info);
                 }
                 if (count($ghelp)) {
+                    foreach ($ghelp as $command=>$info) {
                         printf("\e[1mCommands from parent contexts:\e[0m\n");
                         if (strpos($command," ")!==false) {
                             list($command,$args) = explode(" ",$command,2);
                         } else $args=null;
+                        if (!array_key_exists($command,$ghelp)) continue;
                         $_($command, $args,$info);
                     }
+                }
                 printf("\e[1mGlobal commands:\e[0m\n");
                     $_("exit", null, "Leave the shell");
                     $_(".", null, "Show the context tree");