autofs-5.0.7 - workaround missing GNU versionsort extension

From: Chris Packham <chris.packham@alliedtelesis.co.nz>

alphasort() and scandir() are specified in POSIX.1-2008, versionsort()
is a GNU extension. When versionsort isn't available fallback to using
alphasort.
---

 CHANGELOG            |    1 +
 configure            |   62 ++++++++++++++++++++++++++++++++++++++++++++++++++
 configure.in         |    6 +++++
 include/config.h.in  |    3 ++
 modules/lookup_dir.c |    5 ++++
 5 files changed, 77 insertions(+), 0 deletions(-)


diff --git a/CHANGELOG b/CHANGELOG
index 4eaa9f9..39388a5 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -27,6 +27,7 @@
 - lib/defaults.c: use WITH_LDAP conditional around LDAP types.
 - make yellow pages support optional.
 - modules/replicated.c: use sin6_addr.s6_addr32.
+- workaround missing GNU versionsort extension.
 
 25/07/2012 autofs-5.0.7
 =======================
diff --git a/configure b/configure
index cf6428c..c1423d8 100755
--- a/configure
+++ b/configure
@@ -4010,6 +4010,68 @@ $as_echo "yes" >&6; }
   KRB5_FLAGS=`$KRB5_CONFIG --cflags`
 fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing versionsort" >&5
+$as_echo_n "checking for library containing versionsort... " >&6; }
+if ${ac_cv_search_versionsort+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_func_search_save_LIBS=$LIBS
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char versionsort ();
+int
+main ()
+{
+return versionsort ();
+  ;
+  return 0;
+}
+_ACEOF
+for ac_lib in '' ; do
+  if test -z "$ac_lib"; then
+    ac_res="none required"
+  else
+    ac_res=-l$ac_lib
+    LIBS="-l$ac_lib  $ac_func_search_save_LIBS"
+  fi
+  if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_search_versionsort=$ac_res
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext
+  if ${ac_cv_search_versionsort+:} false; then :
+  break
+fi
+done
+if ${ac_cv_search_versionsort+:} false; then :
+
+else
+  ac_cv_search_versionsort=no
+fi
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_versionsort" >&5
+$as_echo "$ac_cv_search_versionsort" >&6; }
+ac_res=$ac_cv_search_versionsort
+if test "$ac_res" != no; then :
+  test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+
+fi
+
+if test "$ac_cv_search_versionsort" = "no"; then
+
+$as_echo "#define WITHOUT_VERSIONSORT 1" >>confdefs.h
+
+fi
+
 #
 # glibc/libc 6 new libraries
 #
diff --git a/configure.in b/configure.in
index 363c376..4029375 100644
--- a/configure.in
+++ b/configure.in
@@ -163,6 +163,12 @@ AF_SLOPPY_MOUNT()
 AF_CHECK_LIBXML()
 AF_CHECK_KRB5()
 
+AC_SEARCH_LIBS([versionsort],[])
+if test "$ac_cv_search_versionsort" = "no"; then
+	AC_DEFINE(WITHOUT_VERSIONSORT, 1,
+		[Define if your C library does not provide versionsort])
+fi
+
 #
 # glibc/libc 6 new libraries
 #
diff --git a/include/config.h.in b/include/config.h.in
index 7f1c5b5..a2a05a8 100644
--- a/include/config.h.in
+++ b/include/config.h.in
@@ -135,6 +135,9 @@
 /* Define to 1 to use the libtirpc tsd usage workaround */
 #undef TIRPC_WORKAROUND
 
+/* Define if your C library does not provide versionsort */
+#undef WITHOUT_VERSIONSORT
+
 /* Define if using the dmalloc debugging malloc package */
 #undef WITH_DMALLOC
 
diff --git a/modules/lookup_dir.c b/modules/lookup_dir.c
index 33901c0..07471b7 100644
--- a/modules/lookup_dir.c
+++ b/modules/lookup_dir.c
@@ -39,6 +39,11 @@
 #define AUTOFS_DIR_EXT ".autofs"
 #define AUTOFS_DIR_EXTSIZ (sizeof(AUTOFS_DIR_EXT) - 1)
 
+/* Work around non-GNU systems that don't provide versionsort */
+#ifdef WITHOUT_VERSIONSORT
+#define versionsort alphasort
+#endif
+
 struct lookup_context {
   const char *mapname;
 };