Do not require getsubopt() to provide extern char *suboptarg.

We don't use it anyway in mandoc.  Like this, fewer systems need
the compat implementation.  In particular, we can now use the stock
getsubopt() on glibc and musl.

Besides, the comment in the BSD getsubopt.c that error messages are
tricky without *suboptarg is massively overblown.  If you simply
save a copy of the pointer you pass into getsubopt(), that's quite
usable for an error message.

People start campaigning for the addition of *suboptarg to C libraries
on the grounds that mandoc wants it, but actually, i consider library
functions manipulating global data quite ugly, so stop pushing people
into that questionable direction.

While here, add an explicit Copyright header to the test file.
While it's obviously to me what Kristaps intended, others might
consider this file copyrightable and wonder what's up.

3 files changed, 22 insertions, 15 deletions

diff --git a/compat_getsubopt.c b/compat_getsubopt.c
index 3a4a7d4a..880f2f78 100644
--- a/compat_getsubopt.c
+++ b/compat_getsubopt.c
@@ -6,6 +6,7 @@ int dummy;
 
 #else
 
+/*	$Id: compat_getsubopt.c,v 1.5 2014/08/17 20:53:50 schwarze Exp $	*/
 /*	$OpenBSD: getsubopt.c,v 1.4 2005/08/08 08:05:36 espie Exp $	*/
 
 /*-
@@ -41,18 +42,11 @@ int dummy;
 #include <stdlib.h>
 #include <string.h>
 
-/*
- * The SVID interface to getsubopt provides no way of figuring out which
- * part of the suboptions list wasn't matched.  This makes error messages
- * tricky...  The extern variable suboptarg is a pointer to the token
- * which didn't match.
- */
-char *suboptarg;
-
 int
 getsubopt(char **optionp, char * const *tokens, char **valuep)
 {
 	int cnt;
+	char *suboptarg;
 	char *p;
 
 	suboptarg = *valuep = NULL;
diff --git a/configure b/configure
index eb9311e3..baa05ad4 100755
--- a/configure
+++ b/configure
@@ -305,10 +305,8 @@ __HEREDOC__
 [ ${HAVE_FGETLN} -eq 0 ] && \
 	echo "extern	char	 *fgetln(FILE *, size_t *);"
 
-if [ ${HAVE_GETSUBOPT} -eq 0 ]; then
+[ ${HAVE_GETSUBOPT} -eq 0 ] && \
 	echo "extern	int	  getsubopt(char **, char * const *, char **);"
-	echo "extern	char	 *suboptarg;"
-fi
 
 [ ${HAVE_REALLOCARRAY} -eq 0 ] && \
 	echo "extern	void	 *reallocarray(void *, size_t, size_t);"
diff --git a/test-getsubopt.c b/test-getsubopt.c
index 2da98238..b0835697 100644
--- a/test-getsubopt.c
+++ b/test-getsubopt.c
@@ -1,11 +1,26 @@
+/*	$Id: test-getsubopt.c,v 1.3 2014/08/17 20:53:50 schwarze Exp $	*/
+/*
+ * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
 #if defined(__linux__) || defined(__MINT__)
-# define _GNU_SOURCE /* getsubopt() */
+#define _GNU_SOURCE /* getsubopt() */
 #endif
 
 #include <stdlib.h>
 
-extern char *suboptarg;
-
 int
 main(void)
 {
@@ -15,5 +30,5 @@ main(void)
 	char *const tokens[] = { token0, NULL };
 	char *value = NULL;
 	return( ! (0 == getsubopt(&options, tokens, &value)
-	    && suboptarg == buf && value == buf+2 && options == buf+3));
+	    && value == buf+2 && options == buf+3));
 }