user32: Support the MOUSEEVENTF_VIRTUALDESK flag in SendInput().

dlls/user32/input.c

@@ -141,9 +141,18 @@ static void update_mouse_coords( INPUT *input )
 
     if (input->u.mi.dwFlags & MOUSEEVENTF_ABSOLUTE)
     {
+        if (input->u.mi.dwFlags & MOUSEEVENTF_VIRTUALDESK)
+        {
+            RECT rc = get_virtual_screen_rect();
+            input->u.mi.dx = rc.left + ((input->u.mi.dx * (rc.right - rc.left)) >> 16);
+            input->u.mi.dy = rc.top  + ((input->u.mi.dy * (rc.bottom - rc.top)) >> 16);
+        }
+        else
+        {
             input->u.mi.dx = (input->u.mi.dx * GetSystemMetrics( SM_CXSCREEN )) >> 16;
             input->u.mi.dy = (input->u.mi.dy * GetSystemMetrics( SM_CYSCREEN )) >> 16;
         }
+    }
     else
     {
         int accel[3];