[Autoconf] Testsuite fails to catch shell errors

[Pavel Roskin]

Hello!

Somebody running Digital Unix reported recently a problem with
AC_HEADER_TIOCGWINSZ.

It appears that the problem can be reproduced on GNU/Linux (and perhaps
all other OS'es) but the testsuite fails to detect it.

configure from this configure.in:

AC_INIT
AC_HEADER_TIOCGWINSZ
AC_OUTPUT

prints this:

checking for gcc... gcc
checking whether the C compiler works... yes
checking whether we are cross compiling... no
checking whether we are using GNU C... yes
checking whether gcc accepts -g... yes
checking for object suffix... o
checking for Cygwin environment... no
checking for mingw32 environment... no
checking for EMX OS/2 environment... no
checking for executable suffix...
checking POSIX termios... yes
checking how to run the C preprocessor... gcc -E
checking whether termios.h defines TIOCGWINSZ...
./configure: test: !=: unary operator expected
creating ./config.status

and yet the testsuite fails to catch it!

Please avoid blindly putting quotes in every test - that variable
ac_cv_sys_tiocgwinsz_in_termios_h is supposed to be "yes" or "no" so we
should fix the problem rather than to hide it.

What about the testsuite, I suggest to make this change to the testsuite
and fix the failing macros step-by-step:

====================
Index: tests/atspecific.m4
--- tests/atspecific.m4 Tue Sep 19 08:30:17 2000
+++ tests/atspecific.m4 Tue Sep 19 14:00:16 2000
@@ -96,7 +96,7 @@
 dnl lines, so grepping -v warning is not enough.
 AT_CHECK([autoconf --autoconf-dir .. -l $at_srcdir], 0,, ignore)
 AT_CHECK([autoheader --autoconf-dir .. -l $at_srcdir], 0,, ignore)
-AT_CHECK([top_srcdir=$top_srcdir ./configure], 0, ignore, ignore)
+AT_CHECK([top_srcdir=$top_srcdir ./configure], 0, ignore, [])
 test -n "$at_verbose" && echo "--- config.log" && cat config.log
 
 dnl Some tests might exit prematurely when they find a problem, in
====================

There are more problems than just AC_HEADER_TIOCGWINSZ, and all of them
need to be discovered and fixed.

By the way, make sure to install Fortran - there are problems with
AC_F77_FUNC as well.

There is enough work for many people, and yet it needs to be done
really soon.

Regards,
Pavel Roskin