main: fix error message for missing argument

[Akim Demaille]

I was surprised to see:

$ LC_ALL=C bison --defines
bison: --defines: missing operand
Try 'bison --help' for more information.

This must be quite an old error.

I confess I’m confused with the way program_name works: sometimes
it’s complete, sometimes it’s the only basename (because getprogname
and program_name are not the same).  So our error messages are
inconsistent.

Messages from getopt(), full path:

$ LC_ALL=C /opt/local/bin/bison --asd
/opt/local/bin/bison: unrecognized option '--asd'
Try ‘/opt/local/bin/bison --help' for more information.

Messages from error(), base name:

$ LC_ALL=C /opt/local/bin/bison 1 2 3
bison: extra operand '2'
Try '/opt/local/bin/bison --help' for more information.


I’ve had a look at the coreutils, I don’t understand what the
difference is.  It’s not really a big problem, but…

‘Operand’ sounds a bit weird.  I’d rather use ‘argument’.

commit bae14b08b002495416870c7488f0f2f1d184c962
Author: Akim Demaille <address@hidden>
Date:   Thu Oct 4 21:38:32 2018 +0200

    main: fix error message for missing argument
    
    * src/getargs.c (getargs): Don't display any argv other that argv[0]
    when reporting a missing argument.
    * tests/bison.in: Neutralize path differences in stderr.
    * tests/input.at (Invalid number of arguments): New.

diff --git a/src/getargs.c b/src/getargs.c
index 95c681b5..ac9f11c8 100644
--- a/src/getargs.c
+++ b/src/getargs.c
@@ -724,7 +724,7 @@ getargs (int argc, char *argv[])
   if (argc - optind != 1)
     {
       if (argc - optind < 1)
-        error (0, 0, _("%s: missing operand"), quotearg_colon (argv[argc - 
1]));
+        error (0, 0, _("missing operand"));
       else
         error (0, 0, _("extra operand %s"), quote (argv[optind + 1]));
       usage (EXIT_FAILURE);
diff --git a/tests/bison.in b/tests/bison.in
index d3b8ba61..99f7ef40 100644
--- a/tests/bison.in
+++ b/tests/bison.in
@@ -25,9 +25,15 @@ abs_top_builddir='@abs_top_builddir@'
 BISON_PKGDATADIR=$abs_top_srcdir/data
 export BISON_PKGDATADIR
 
-$PREBISON "$abs_top_builddir/src/bison" ${1+"$@"}
+stderr=tmp-bison.$$
+$PREBISON "$abs_top_builddir/src/bison" ${1+"$@"} 2>"$stderr"
 status=$?
 
+# Neutralize path differences in error messages so that check and
+# installcheck behave the same way.
+sed -e "s,$abs_top_builddir/src/,,g" <"$stderr" >&2
+rm -f "$stderr"
+
 # As a special dark magic, if we are actually using this wrapper to
 # compile Bison's src/parse-gram.y, post-process the synclines to
 # avoid dependencies on the user's set up (srcdir vs. builddir).
diff --git a/tests/input.at b/tests/input.at
index 527c0398..9b8c453b 100644
--- a/tests/input.at
+++ b/tests/input.at
@@ -20,6 +20,31 @@ AT_BANNER([[Input Processing.]])
 # Mostly test that we are robust to mistakes.
 
 
+## ----------------------------- ##
+## Invalid number of arguments.  ##
+## ----------------------------- ##
+
+AT_SETUP([Invalid number of arguments])
+
+AT_BISON_CHECK([], [1], [],
+[[bison: missing operand
+Try 'bison --help' for more information.
+]])
+
+AT_BISON_CHECK([1.y 2.y], [1], [],
+[[bison: extra operand '2.y'
+Try 'bison --help' for more information.
+]])
+
+AT_BISON_CHECK([--skeleton], [1], [],
+[[bison: option '--skeleton' requires an argument
+Try 'bison --help' for more information.
+]])
+
+AT_CLEANUP
+
+
+
 ## ----------------- ##
 ## Invalid options.  ##
 ## ----------------- ##