From: Maarten ter Huurne <maarten@treewalker.org>
Date: Sun, 14 Sep 2014 11:16:58 +0200
Subject: Avoid mis-identifying systems as SVR4

My openSUSE 13.1 Linux system was detected as SVR4 because it had
libelf installed. This leads to linking with libelf, even though no
symbols from that library were actually used, and to a workaround for
a buggy getlogin() being enabled.

It is not documented which exact SVR4 system had the bug that the
workaround was added for, so all I could do is make an educated guess
at the #defines its compiler would be likely to set.

Signed-off-by: Maarten ter Huurne <maarten@treewalker.org>
---
 configure.in | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/configure.in b/configure.in
index f78f81f..181b7f9 100644
--- a/configure.in
+++ b/configure.in
@@ -178,14 +178,24 @@ AC_EGREP_CPP(yes,
 #endif
 ], LIBS="$LIBS -lsocket -linet";seqptx=1)
 
+AC_CHECKING(SVR4)
+AC_EGREP_CPP(yes,
+[main () {
+#if defined(SVR4) || defined(__SVR4)
+  yes;
+#endif
+], AC_NOTE(- you have a SVR4 system) AC_DEFINE(SVR4) svr4=1)
+if test -n "$svr4" ; then
 oldlibs="$LIBS"
 LIBS="$LIBS -lelf"
 AC_CHECKING(SVR4)
 AC_TRY_LINK([#include <utmpx.h>
 ],,
-[AC_CHECK_HEADER(dwarf.h, AC_DEFINE(SVR4) AC_DEFINE(BUGGYGETLOGIN),
-[AC_CHECK_HEADER(elf.h, AC_DEFINE(SVR4) AC_DEFINE(BUGGYGETLOGIN))])]
+[AC_CHECK_HEADER(dwarf.h, AC_DEFINE(BUGGYGETLOGIN),
+[AC_CHECK_HEADER(elf.h, AC_DEFINE(BUGGYGETLOGIN))])]
 ,LIBS="$oldlibs")
+fi
+
 AC_CHECK_HEADERS([stropts.h string.h strings.h])
 
 AC_CHECKING(for Solaris 2.x)
-- 
1.8.4.5