Check both -lrt and -lposix4 for fdatasync, to cover all Solaris versions.

configure

@@ -4407,7 +4407,7 @@ else
   cat conftest.$ac_ext >&5
 fi
 rm -f conftest*
-test "$ac_cv_search_fdatasync" = "no" && for i in rt; do
+test "$ac_cv_search_fdatasync" = "no" && for i in rt posix4; do
 LIBS="-l$i  $ac_func_search_save_LIBS"
 cat > conftest.$ac_ext <<EOF
 #line 4414 "configure"
@@ -8051,7 +8051,7 @@ EOF
 
 else
   echo "$ac_t""no" 1>&6
-{ echo "configure: error: atexi() nor on_exit() found" 1>&2; exit 1; }
+{ echo "configure: error: neither atexit() nor on_exit() found" 1>&2; exit 1; }
 fi
 done
 

configure.in

@@ -751,7 +751,7 @@ AC_EGREP_HEADER(z_streamp, zlib.h, [
 AC_CHECK_LIB(z,        inflate)
 ])
 # Solaris:
-AC_SEARCH_LIBS(fdatasync, rt)
+AC_SEARCH_LIBS(fdatasync, [rt posix4])
 
 if test "$with_krb4" = yes ; then
   AC_CHECK_LIB(des, [des_encrypt], [], [AC_MSG_ERROR([library 'des' is required for Kerberos 4])])
@@ -1161,7 +1161,7 @@ AC_CHECK_FUNC(atexit,
 	[AC_DEFINE(HAVE_ATEXIT)],
 	[AC_CHECK_FUNCS(on_exit,
 		[AC_DEFINE(HAVE_ON_EXIT)],
-		[AC_MSG_ERROR([atexi() nor on_exit() found])])])
+		[AC_MSG_ERROR([neither atexit() nor on_exit() found])])])
 
 dnl Need a #define for the size of Datum (unsigned long)