[csrss]

- Paint the desktop only when getting WM_ERASEBKGND message, and do nothing in WM_PAINT. This is the behavior Windows and Wine implement.
- Add WM_CLOSE stub-handler, though it doesn't change much now - all messages unhandled by the switch are going to return "0" since this proc doesn't call DefWndProcHandler.

svn path=/trunk/; revision=43934

reactos/subsystems/win32/csrss/win32csr/desktopbg.c

@@ -42,23 +42,19 @@ static HWND VisibleDesktopWindow = NULL;
 static LRESULT CALLBACK
 DtbgWindowProc(HWND Wnd, UINT Msg, WPARAM wParam, LPARAM lParam)
 {
-  switch(Msg)
+  PAINTSTRUCT PS;
+  HDC hDC;
+
+    switch(Msg)
     {
       case WM_ERASEBKGND:
+        PaintDesktop((HDC)wParam);
         return 1;
 
       case WM_PAINT:
       {
-        PAINTSTRUCT PS;
-        RECT rc;
-        HDC hDC;
-
-        if(GetUpdateRect(Wnd, &rc, FALSE) &&
-           (hDC = BeginPaint(Wnd, &PS)))
-        {
-          PaintDesktop(hDC);
+        if((hDC = BeginPaint(Wnd, &PS)))
           EndPaint(Wnd, &PS);
-        }
         return 0;
       }
 
@@ -71,6 +67,9 @@ DtbgWindowProc(HWND Wnd, UINT Msg, WPARAM wParam, LPARAM lParam)
       case WM_CREATE:
         return 0;
 
+      case WM_CLOSE:
+        return 0;
+
       case WM_NOTIFY:
       {
         PPRIVATE_NOTIFY_DESKTOP nmh = (PPRIVATE_NOTIFY_DESKTOP)lParam;