[patch] Allow to link with ncursesw

[John Baldwin]

On Wednesday, September 20, 2017 10:22:29 PM Pedro Alves wrote:
> On 09/20/2017 08:51 PM, Matthias Klose wrote:
> > On 20.09.2017 20:39, Pedro Alves wrote:
> 
> >> Did you reach out to readline/bash, see if they're willing
> >> to try ncursesw before ncurses too?  Don't we need at least
> >> a local patch to our local readline copy, to avoid breaking
> >> those that use it and have it link with ncurses?
> > 
> > afaik, this is only the case if readline is linked with one of the curses
> > libraries.  However these days everybody seems to have readline linked to just
> > tinfo, so this shouldn't be an issue?
> 
> Everybody on GNU/Linux, it seems.  However, the Python bug
> report talked about FreeBSD's readline linked with ncurses
> Do you know whether they've switched to tinfo as well
> meanwhile?  [Adding John as FreeBSD maintainer.]

FreeBSD still links libreadline against curses:

% ldd /usr/local/lib/libreadline.so.7
/usr/local/lib/libreadline.so.7:
        libncursesw.so.8 => /lib/libncursesw.so.8 (0x801251000)
        libc.so.7 => /lib/libc.so.7 (0x800825000)

However, it seems to be linked against libncursesw.  gdb on this same
system (11.1) is linked against both ncurses libraries:

% ldd /usr/local/bin/gdb80 
/usr/local/bin/gdb80:
        libreadline.so.7 => /usr/local/lib/libreadline.so.7 (0x801dda000)
        libncurses.so.8 => /lib/libncurses.so.8 (0x80202b000)
        libkvm.so.7 => /lib/libkvm.so.7 (0x802281000)
        libutil.so.9 => /lib/libutil.so.9 (0x80248f000)
        libm.so.5 => /lib/libm.so.5 (0x8026a3000)
        libthr.so.3 => /lib/libthr.so.3 (0x8028cd000)
        libintl.so.8 => /usr/local/lib/libintl.so.8 (0x802af5000)
        libpython2.7.so.1 => /usr/local/lib/libpython2.7.so.1 (0x802d00000)
        libexpat.so.1 => /usr/local/lib/libexpat.so.1 (0x8030e3000)
        liblzma.so.5 => /usr/lib/liblzma.so.5 (0x80330e000)
        libc++.so.1 => /usr/lib/libc++.so.1 (0x803537000)
        libcxxrt.so.1 => /lib/libcxxrt.so.1 (0x803801000)
        libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x803a20000)
        libc.so.7 => /lib/libc.so.7 (0x803c2f000)
        libncursesw.so.8 => /lib/libncursesw.so.8 (0x803fec000)
        libelf.so.2 => /lib/libelf.so.2 (0x80424b000)

Given that readline on FreeBSD now uses ncursesw and that the original
python report was from several years ago when that probably wasn't true,
I'm inclined to think that using ncursesw might be fine.  I'll try a test
build of this patch tomorrow.

-- 
John Baldwin