Merge branch 'systray_show' into 'master'

explorer: Prevent apps from showing Wine specific shell tray window with no icons.

See merge request wine/wine!6728

programs/explorer/systray.c

@@ -1110,6 +1110,18 @@ static LRESULT WINAPI shell_traywnd_proc( HWND hwnd, UINT msg, WPARAM wparam, LP
         else do_show_systray();
         break;
 
+    case WM_WINDOWPOSCHANGING:
+    {
+        WINDOWPOS *p = (WINDOWPOS *)lparam;
+
+        if (p->flags & SWP_SHOWWINDOW && (!show_systray || (!nb_displayed && !enable_taskbar)))
+        {
+            TRACE( "WM_WINDOWPOSCHANGING clearing SWP_SHOWWINDOW.\n" );
+            p->flags &= ~SWP_SHOWWINDOW;
+        }
+        break;
+    }
+
     case WM_MOVE:
         update_systray_balloon_position();
         break;