Re: emacs-29 b54febef5d7: Fix NetBSD build with and without ncurses

Re: emacs-29 b54febef5d7: Fix NetBSD build with and without ncurses

[Po Lu]

Eli Zaretskii <eliz@gnu.org> writes:

> branch: emacs-29
> commit b54febef5d735efdc907c5e5cd016bed74e338a8
> Author: Valtteri Vuorikoski <vuori@notcom.org>
> Commit: Eli Zaretskii <eliz@gnu.org>
>
>     Fix NetBSD build with and without ncurses
>     
>     * configure.ac (netbsd): Don't set TERMINFO=no unless the termcap
>     library is either -ltermcap or -lcurses.  This prevents aborts
>     because on recent versions of NetBSD libtermcap is actually a
>     symlink to libterminfo. (Bug#64577)
>     
>     Copyright-paperwork-exempt: yes
> ---
>  configure.ac | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/configure.ac b/configure.ac
> index 19575e80cf4..df74f8cd2f8 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -5212,7 +5212,11 @@ fail;
>      ;;
>  
>    netbsd)
> -    if test "x$LIBS_TERMCAP" != "x-lterminfo"; then
> +    # NetBSD versions prior to 6.0 lack native terminfo, but have a
> +    # tputs() built on top of termcap in these libraries. Use native
> +    # termcap instead in this case. NetBSD >= 6.0 has native terminfo
> +    # implementation in -lterminfo.
> +    if test "x$LIBS_TERMCAP" = "x-ltermcap" -o "x$LIBS_TERMCAP" = "x-lcurses"; then

From (autoconf)Portable Shell:

     The `-a', `-o', `(', and `)' operands are not present in all
     implementations, and have been marked obsolete by Posix 2008.  This
     is because there are inherent ambiguities in using them.  For
     example, `test "$1" -a "$2"' looks like a binary operator to check
     whether two strings are both non-empty, but if `$1' is the literal
     `!', then some implementations of `test'' treat it as a negation of
     the unary operator `-a'.

Will anyone object if I change this to:

  AS_IF([test "x$LIBS_TERMCAP" != "x-lterminfo" \
         || test "x$LIBS_TERMCAP" = "x-lcurses"],
        [...])

on the release branch?

Re: emacs-29 b54febef5d7: Fix NetBSD build with and without ncurses

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: Valtteri Vuorikoski <vuori@notcom.org>
> Date: Sun, 16 Jul 2023 18:02:44 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > -    if test "x$LIBS_TERMCAP" != "x-lterminfo"; then
> > +    # NetBSD versions prior to 6.0 lack native terminfo, but have a
> > +    # tputs() built on top of termcap in these libraries. Use native
> > +    # termcap instead in this case. NetBSD >= 6.0 has native terminfo
> > +    # implementation in -lterminfo.
> > +    if test "x$LIBS_TERMCAP" = "x-ltermcap" -o "x$LIBS_TERMCAP" = "x-lcurses"; then
> 
> >From (autoconf)Portable Shell:
> 
>      The `-a', `-o', `(', and `)' operands are not present in all
>      implementations, and have been marked obsolete by Posix 2008.  This
>      is because there are inherent ambiguities in using them.  For
>      example, `test "$1" -a "$2"' looks like a binary operator to check
>      whether two strings are both non-empty, but if `$1' is the literal
>      `!', then some implementations of `test'' treat it as a negation of
>      the unary operator `-a'.

We use -o in other places with 'test'.  So this is evidently not a
problem.

> Will anyone object if I change this to:
> 
>   AS_IF([test "x$LIBS_TERMCAP" != "x-lterminfo" \
>          || test "x$LIBS_TERMCAP" = "x-lcurses"],
>         [...])
> 
> on the release branch?

Please don't.

Re: emacs-29 b54febef5d7: Fix NetBSD build with and without ncurses

[Po Lu]

Eli Zaretskii <eliz@gnu.org> writes:

> We use -o in other places with 'test'.

Not in Emacs 28.

configure.in only contains `test ... -o ...' in two places, both
additions in Emacs 29, which will also affect user's ability to
configure Emacs.  So I would really prefer to have this fixed in the
release branch.

> So this is evidently not a problem.

Dozens of years of Autoconf developers' experience says otherwise.

Re: emacs-29 b54febef5d7: Fix NetBSD build with and without ncurses

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: emacs-devel@gnu.org,  vuori@notcom.org
> Date: Sun, 16 Jul 2023 19:55:52 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > We use -o in other places with 'test'.
> 
> Not in Emacs 28.

We are not releasing Emacs 28 anymore.

> configure.in only contains `test ... -o ...' in two places, both
> additions in Emacs 29, which will also affect user's ability to
> configure Emacs.  So I would really prefer to have this fixed in the
> release branch.
> 
> > So this is evidently not a problem.
> 
> Dozens of years of Autoconf developers' experience says otherwise.

Sorry, I'm not going to install unnecessary changes on emacs-29 at
this stage.  It's too late for that.  The change I installed was
tested on the only affected system, and any further changes mean more
delays and/or risk of introducing bugs.

Re: emacs-29 b54febef5d7: Fix NetBSD build with and without ncurses

[Po Lu]

Eli Zaretskii <eliz@gnu.org> writes:

> Sorry, I'm not going to install unnecessary changes on emacs-29 at
> this stage.  It's too late for that.  The change I installed was
> tested on the only affected system, and any further changes mean more
> delays and/or risk of introducing bugs.

That change is to Shell syntax within configure.ac, which affects every
single system we support.