Imported Upstream version 2.6.3

m4/nut_check_libltdl.m4

@@ -0,0 +1,27 @@
+dnl Check for LIBLTDL compiler flags. On success, set nut_have_libltdl="yes"
+dnl and set LIBLTDL_CFLAGS and LIBLTDL_LIBS. On failure, set
+dnl nut_have_libltdl="no". This macro can be run multiple times, but will
+dnl do the checking only once. 
+
+AC_DEFUN([NUT_CHECK_LIBLTDL], 
+[
+if test -z "${nut_have_libltdl_seen}"; then
+	nut_have_libltdl_seen=yes
+
+	dnl save LIBS
+	LIBS_ORIG="${LIBS}"
+	LIBS=""
+
+	AC_CHECK_HEADERS(ltdl.h, [nut_have_libltdl=yes], [nut_have_libltdl=no], [AC_INCLUDES_DEFAULT])
+	AC_SEARCH_LIBS(lt_dlinit, ltdl, [], [nut_have_libltdl=no])
+
+	if test "${nut_have_libltdl}" = "yes"; then
+		AC_DEFINE(HAVE_LIBLTDL, 1, [Define to enable libltdl support])
+		LIBLTDL_CFLAGS=""
+		LIBLTDL_LIBS="${LIBS}"
+	fi
+
+	dnl restore original LIBS
+	LIBS="${LIBS_ORIG}"
+fi
+])