Merge branch 'upstream-LibArchive' into update-libarchive

Resolve conflicts in C code by taking their side.  Resolve conflicts in
CMake code by integrating the changes.

1 files changed, 12 insertions, 1 deletions

diff --git a/Utilities/cmlibarchive/libarchive/archive_hmac_private.h b/Utilities/cmlibarchive/libarchive/archive_hmac_private.h
index a9fb8ec..64de743 100644
--- a/Utilities/cmlibarchive/libarchive/archive_hmac_private.h
+++ b/Utilities/cmlibarchive/libarchive/archive_hmac_private.h
@@ -30,6 +30,17 @@
 #ifndef ARCHIVE_HMAC_PRIVATE_H_INCLUDED
 #define ARCHIVE_HMAC_PRIVATE_H_INCLUDED
 
+/*
+ * On systems that do not support any recognized crypto libraries,
+ * the archive_hmac.c file is expected to define no usable symbols.
+ *
+ * But some compilers and linkers choke on empty object files, so
+ * define a public symbol that will always exist.  This could
+ * be removed someday if this file gains another always-present
+ * symbol definition.
+ */
+int __libarchive_hmac_build_hack(void);
+
 #ifdef __APPLE__
 # include <AvailabilityMacros.h>
 # if MAC_OS_X_VERSION_MAX_ALLOWED >= 1060
@@ -53,7 +64,7 @@ typedef struct {
 
 } archive_hmac_sha1_ctx;
 
-#elif defined(HAVE_LIBNETTLE)
+#elif defined(HAVE_LIBNETTLE) && defined(HAVE_NETTLE_HMAC_H)
 #include <nettle/hmac.h>
 
 typedef	struct hmac_sha1_ctx archive_hmac_sha1_ctx;