Configure: Check if libfetch version is >= 2.21

Commit 6f97842 started using libfetch's conditional GET. This requires
libfetch to be version 2.21 or greater.

Change configure.ac to check for the existence of the last_modified field in
the url struct, which was introduced with libfetch 2.21.

Signed-off-by: Henning Garus <henning.garus@gmail.com>
[Xav : moved AC_CHECK_MEMBER outside of AC_CHECK_LIB]
Signed-off-by: Xavier Chantry <shiningxc@gmail.com>
Signed-off-by: Dan McGee <dan@archlinux.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/configure.ac b/configure.ac
index b2164b9e..2c08d790 100644
--- a/configure.ac
+++ b/configure.ac
@@ -144,6 +144,11 @@ if test "x$internaldownload" = "xyes" ; then
 	# Check for a download library if it was actually requested
 	AC_CHECK_LIB([fetch], [fetchParseURL], ,
 		AC_MSG_ERROR([libfetch is needed to compile with internal download support]) )
+	# Check if libfetch supports conditional GET
+	# (version >=2.21, struct url has member last_modified)
+	AC_CHECK_MEMBER(struct url.last_modified, ,
+		AC_MSG_ERROR([libfetch must be version 2.21 or greater]),
+		[#include <fetch.h>] )
 else
 	AC_MSG_RESULT(no)
 fi