According to this message on bug-ncurses, the fixes could be incomplete,
although I doubt that person is using the exact same subset of the
upstream patch as the one I am proposing:

https://lists.gnu.org/archive/html/bug-ncurses/2017-07/msg00008.html

On the general subject of ncurses bugs, the ncurses author issues patch
releases for ncurses frequently:

ftp://invisible-island.net/ncurses/6.0/

I didn't know that and I haven't read the changelogs to see if there are
other very important fixes for us to use.