server: Allow creating a real explorer desktop window for invisible window stations.

dlls/user32/tests/winstation.c

@@ -1049,7 +1049,6 @@ static void test_invisible_winstation_child(char *expected_info)
     ok(!!hwnd, "GetDesktopWindow failed, error %lu.\n", GetLastError());
 
     ret = SendMessageW(hwnd, WM_NCHITTEST, 0, 0);
-    todo_wine
     ok(ret == HTCLIENT, "SendMessageW failed, error %lu.\n", GetLastError());
 }
 

dlls/win32u/winstation.c

@@ -420,14 +420,24 @@ static inline TEB64 *NtCurrentTeb64(void) { return (TEB64 *)NtCurrentTeb()->GdiB
 
 HWND get_desktop_window(void)
 {
+    static const WCHAR wine_service_station_name[] =
+        {'_','_','w','i','n','e','s','e','r','v','i','c','e','_','w','i','n','s','t','a','t','i','o','n',0};
     struct ntuser_thread_info *thread_info = NtUserGetThreadInfo();
+    WCHAR name[MAX_PATH];
+    BOOL is_service;
 
     if (thread_info->top_window) return UlongToHandle( thread_info->top_window );
 
+    /* don't create an actual explorer desktop window for services */
+    if (NtUserGetObjectInformation( NtUserGetProcessWindowStation(), UOI_NAME, name, sizeof(name), NULL )
+        && !wcscmp( name, wine_service_station_name ))
+        is_service = TRUE;
+    else
+        is_service = FALSE;
 
     SERVER_START_REQ( get_desktop_window )
     {
-        req->force = 0;
+        req->force = is_service;
         if (!wine_server_call( req ))
         {
             thread_info->top_window = reply->top_window;

server/window.c

@@ -2151,14 +2151,10 @@ DECL_HANDLER(destroy_window)
 DECL_HANDLER(get_desktop_window)
 {
     struct desktop *desktop = get_thread_desktop( current, 0 );
-    int force;
 
     if (!desktop) return;
 
-    /* if winstation is invisible, then avoid roundtrip */
-    force = req->force || !(desktop->winstation->flags & WSF_VISIBLE);
-
-    if (!desktop->top_window && force)  /* create it */
+    if (!desktop->top_window && req->force)  /* create it */
     {
         if ((desktop->top_window = create_window( NULL, NULL, DESKTOP_ATOM, 0 )))
         {
@@ -2167,7 +2163,7 @@ DECL_HANDLER(get_desktop_window)
         }
     }
 
-    if (!desktop->msg_window && force)  /* create it */
+    if (!desktop->msg_window && req->force)  /* create it */
     {
         static const WCHAR messageW[] = {'M','e','s','s','a','g','e'};
         static const struct unicode_str name = { messageW, sizeof(messageW) };