Comment 8 for bug 1116006

All the above 3 patches were already included in 5.16, i.e.
* xscreensaver-demo does truncate http:// into http:/
* xscreensaver-demo now uses memmove instead of strcpy when source and destination overlaps, which will _perhaps_ fix some strange about "degraeve" into "degraee" and so on.

For reference, the diff of demo-Gtk.c between 5.15 and 5.16 is attached.