core: In user mode checkouts of archives, use hard links

Now that we've done all the gyrations to separate content from
metadata in archives, we can just hard link when doing user checkouts.

src/libostree/ostree-repo.c

@@ -2262,7 +2262,18 @@ checkout_tree (OstreeRepo               *self,
         {
           const char *checksum = _ostree_repo_file_get_checksum ((OstreeRepoFile*)src_child);
 
-          if (priv->mode == OSTREE_REPO_MODE_ARCHIVE)
+          if (priv->mode == OSTREE_REPO_MODE_ARCHIVE && mode == OSTREE_REPO_CHECKOUT_MODE_USER)
+            {
+              g_clear_object (&object_path);
+              object_path = ostree_repo_get_object_path (self, checksum, OSTREE_OBJECT_TYPE_ARCHIVED_FILE_CONTENT);
+
+              if (link (ot_gfile_get_path_cached (object_path), ot_gfile_get_path_cached (dest_path)) < 0)
+                {
+                  ot_util_set_error_from_errno (error, errno);
+                  goto out;
+                }
+            }
+          else if (priv->mode == OSTREE_REPO_MODE_ARCHIVE)
             {
               ot_clear_gvariant (&archive_metadata);
               if (!ostree_repo_load_variant (self, OSTREE_OBJECT_TYPE_ARCHIVED_FILE_META, checksum, &archive_metadata, error))

tests/t0000-basic.sh

@@ -19,7 +19,7 @@
 
 set -e
 
-echo "1..17"
+echo "1..18"
 
 . libtest.sh
 
@@ -148,3 +148,6 @@ ostree --repo=repo2 checkout test2 test2-checkout-from-local-clone
 cd test2-checkout-from-local-clone
 assert_file_has_content yet/another/tree/green 'leaf'
 echo "ok local clone checkout"
+
+$OSTREE checkout -U test2 checkout-user-test2
+echo "ok user checkout"

tests/t0001-archive.sh

@@ -21,7 +21,7 @@ set -e
 
 . libtest.sh
 
-echo '1..5'
+echo '1..6'
 
 setup_test_repository "archive"
 echo "ok setup"
@@ -47,3 +47,6 @@ ostree --repo=repo2 checkout test2 test2-checkout-from-local-clone
 cd test2-checkout-from-local-clone
 assert_file_has_content baz/cow moo
 echo "ok local clone checkout"
+
+$OSTREE checkout -U test2 checkout-user-test2
+echo "ok user checkout"