Strange terminal with ncurses 6.0 and readline

[BERTRAND Joël]

        Hello,

	I'm using readline and ncurses on a huge program I write for a long 
time (http://www.rpl2.net). Yesterday, I have upgraded ncurses from last 
5.9 patch to 6.0. I have seen some trouble with readline. For example, 
backpspace doesn't work anymore :

rayleigh:[~/gopher/rpl2/build-amd64/src] > rpl -is
+++RPL/2 (R) version 4.1.22 (Mercredi 15/07/2015, 13:20:38 CEST)
+++Copyright (C) 1989 à 2014, 2015 BERTRAND Joël

+++Ce logiciel est un logiciel libre sans aucune garantie de fonctionnement.
+++Pour plus de détails, utilisez la commande 'warranty'.

RPL/2> azerty      1234

1: 1234
RPL/2>

	All backspaces are printed as regular space even if 'azerty' string is 
delete. Arrow keys doesn't work anymore as expected. If I link the same 
program against ncurses 5.9, it runs like a charm.

	I don't understand interaction between ncurses and readline. My program 
is statically linked against readline _and_ ncurses.

        Best regards,

        JKB