lib/remote: Store name of remote providing keyring for dynamic remotes

When pulling from a dynamic (peer to peer) remote, the remote’s name is
set to a unique, generated string which doesn’t exist in repo/config. If
doing a non-mirror pull, however, we don’t want to use this name in the
refspecs for newly created or updated refs — we want to use the name of
the remote which provided the keyring for the pull (this will be a
remote from repo/config whose collection ID matches that being used for
the peer to peer pull).

Store both names in OstreeRemote. The name to use for refspecs is stored
as refspec_name, and is typically NULL unless it differs from name.

Signed-off-by: Philip Withnall <withnall@endlessm.com>

Closes: #1202
Approved by: cgwalters

src/libostree/ostree-repo-finder-avahi.c

@@ -821,7 +821,7 @@ ostree_avahi_service_build_repo_finder_result (OstreeAvahiService
       /* Build an #OstreeRemote. Use the escaped URI, since remote->name
        * is used in file paths, so needs to not contain special characters. */
       g_autofree gchar *name = uri_and_keyring_to_name (repo);
-      remote = ostree_remote_new (name);
+      remote = ostree_remote_new_dynamic (name, repo->keyring_remote->name);
 
       g_clear_pointer (&remote->keyring, g_free);
       remote->keyring = g_strdup (repo->keyring_remote->keyring);