Re: RL_LIB_READLINE_VERSION

[Ralf Wildenhues]

* Ralf Corsepius wrote on Mon, Jan 16, 2006 at 06:36:34AM CET:
> On Sun, 2006-01-15 at 12:09 -0500, Bob Rossi wrote:
> > > * Bob Rossi wrote on Sat, Jan 14, 2006 at 10:15:10PM CET:
> > > > 
> > > > >   config/readline_check_version.m4:1: warning: underquoted definition
> > > > >   of BASH_CHECK_LIB_TERMCAP

> > Yeah, switching from debian to ubuntu really is nice. Just out of
> > curiosity, what's the reason for the change?
> Bugs - The autoconf-2.13 syntax is broken and relied upon exploiting
> improper code.

AC_DEFINE(foo, [bar baz])
AC_DEFINE(foo, [bar baz])

will cause an error, because in the second line, `foo' is expanded to
`bar baz' before AC_DEFINE is evaluated, so you're trying to define a
macro named `bar baz'.  This won't happen if the second line reads

AC_DEFINE([foo], [bar baz])

Combine that with the fact that newer aclocal versions may evaluate the
same macro definitions more than once.

The "new" syntax is backward-compatible to the dark ages, and should
have been, had it not been for the lazyness of the people in the dark
ages, used and promoted from day one.

Cheers,
Ralf