gettext 0.18.1: fallback for AC_USE_SYSTEM_EXTENSIONS in fcntl-o.m4

[Christian Weisgerber]

Pulling in the new AM_GNU_GETTEXT macro from gettext 0.18.1 causes
errors with older versions of autoconf, such as 2.59, because
AC_USE_SYSTEM_EXTENSIONS is required but not defined.  The requirement
originates in fcntl-o.m4.  Maybe it is possible to fallback to
AC_GNU_SOURCE there as is done in threadlib.m4.


--- gettext-runtime/m4/fcntl-o.m4.orig  Thu Jul  1 07:44:09 2010
+++ gettext-runtime/m4/fcntl-o.m4       Thu Jul  1 07:44:43 2010
@@ -12,7 +12,9 @@ dnl Written by Paul Eggert.
 AC_DEFUN([gl_FCNTL_O_FLAGS],
 [
   dnl Persuade glibc <fcntl.h> to define O_NOATIME and O_NOFOLLOW.
-  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+  m4_ifdef([AC_USE_SYSTEM_EXTENSIONS],
+    [AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])],
+    [AC_REQUIRE([AC_GNU_SOURCE])])
   AC_CACHE_CHECK([for working fcntl.h], [gl_cv_header_working_fcntl_h],
     [AC_RUN_IFELSE(
        [AC_LANG_PROGRAM(
-- 
Christian "naddy" Weisgerber                          address@hidden