Lock WindowForClientLooperPort method and add comment that the window lock has to be held if accessing the a WindowList.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@38215 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/servers/app/Desktop.cpp

@@ -2487,6 +2487,8 @@ Desktop::AllWindows()
 Window*
 Desktop::WindowForClientLooperPort(port_id port)
 {
+	AutoReadLocker locker(fWindowLock);
+
 	for (Window* window = fAllWindows.FirstWindow(); window != NULL;
 			window = window->NextWindow(kAllWindowList)) {
 		if (window->ServerWindow()->ClientLooperPort() == port)

src/servers/app/Desktop.h

@@ -257,6 +257,7 @@ public:
 			void				WriteWindowOrder(int32 workspace,
 									BPrivate::LinkSender& sender);
 
+			//! The window lock has to be held when accessing a window list!
 			WindowList&			CurrentWindows();
 			WindowList&			AllWindows();