undefine before redefining

diff --git a/m4/isc-posix.m4 b/m4/isc-posix.m4
index 4dd2afa..7f4a166 100644 (file)
--- a/m4/isc-posix.m4
+++ b/m4/isc-posix.m4
@@ -1,12 +1,13 @@
 #serial 1
-# This test replaces the one in autoconf.
-# Currently this macro should have the same name as the autoconf macro
-# because gettext's gettext.m4 (distributed in the automake package)
-# still uses it.  Otherwise, the use in gettext.m4 makes autoheader
-# give these diagnostics:
-#   configure.in:556: AC_TRY_COMPILE was called before AC_ISC_POSIX
-#   configure.in:556: AC_TRY_RUN was called before AC_ISC_POSIX
+dnl This test replaces the one in autoconf.
+dnl Currently this macro should have the same name as the autoconf macro
+dnl because gettext's gettext.m4 (distributed in the automake package)
+dnl still uses it.  Otherwise, the use in gettext.m4 makes autoheader
+dnl give these diagnostics:
+dnl   configure.in:556: AC_TRY_COMPILE was called before AC_ISC_POSIX
+dnl   configure.in:556: AC_TRY_RUN was called before AC_ISC_POSIX
 
+undefine([AC_ISC_POSIX])
 AC_DEFUN(AC_ISC_POSIX,
   [
     dnl This test replaces the obsolescent AC_ISC_POSIX kludge.