a libtool.m4 patch

[Bruno Haible]

Hi,

libtool-1.4 libtool.m4, when used together with autoconf-2.13, leads to
autoconf errors due to its use of the 'symbols' builtin in comments.

To reproduce:
  - take gettext-0.10.38,
  - replace m4/libtool.m4 and ltmain.sh with the ones from libtool-1.4,
  - run "./aclocal.sh aclocal -I m4"
  - run "automake --gnits --include-deps Makefile"
  - run "autoconf"

I get
  autoconf: Undefined macros:
  configure.in:43:jm_AC_TYPE_UNSIGNED_LONG_LONG

The error message is a red herring (yes, autoconf-2.13 error reporting is
not good). When I search for jm_AC_TYPE_UNSIGNED_LONG_LONG in the generated
configure, I see constructions like this:

/* The mapping between symbol names and AC_ACVERSION,...[many macro 
names],undivert. */

They come from libtool.m4 using the 'symbols' builtin of m4. The following
patch fixes it. Note the problem doesn't occur with autoconf-2.50 any more,
but I would like to support autoconf-2.13 for quite some time in my *.m4
macros. The patch below has no effect in autoconf-2.50.


*** libtool.m4.bak      Fri Jun  8 23:54:45 2001
--- libtool.m4  Thu Jun 14 13:26:54 2001
***************
*** 22,27 ****
--- 22,30 ----
  ## configuration script generated by Autoconf, you may include it under
  ## the same distribution terms that you use for the rest of that program.
  
+ # The next line was added by Bruno Haible 2001-06-08.
+ builtin([undefine],[symbols])
+ 
  # serial 46 AC_PROG_LIBTOOL
  AC_DEFUN([AC_PROG_LIBTOOL],
  [AC_REQUIRE([AC_LIBTOOL_SETUP])dnl