git_repository_set_head: use remote name in reflog

When `git_repository_set_head` is provided a remote reference, update
the reflog with the tag name, like we do with a branch.  This helps
consumers match the semantics of `git checkout remote`.

src/repository.c

@@ -2525,7 +2525,9 @@ static int checkout_message(git_buf *out, git_reference *old, const char *new)
 
 	git_buf_puts(out, " to ");
 
-	if (git_reference__is_branch(new) || git_reference__is_tag(new))
+	if (git_reference__is_branch(new) ||
+		git_reference__is_tag(new) ||
+		git_reference__is_remote(new))
 		git_buf_puts(out, git_reference__shorthand(new));
 	else
 		git_buf_puts(out, new);
@@ -2603,7 +2605,7 @@ int git_repository_set_head(
 					git_reference_name(ref), true, git_buf_cstr(&log_message));
 		} else {
 			error = detach(repo, git_reference_target(ref),
-				git_reference_is_tag(ref) ? refname : NULL);
+				git_reference_is_tag(ref) || git_reference_is_remote(ref) ? refname : NULL);
 		}
 	} else if (git_reference__is_branch(refname)) {
 		error = git_reference_symbolic_create(&new_head, repo, GIT_HEAD_FILE, refname,

tests/repo/head.c

@@ -262,16 +262,18 @@ void test_repo_head__setting_head_updates_reflog(void)
 	cl_git_pass(git_repository_set_head_detached(repo, git_object_id(tag)));
 	cl_git_pass(git_repository_set_head(repo, "refs/heads/haacked"));
 	cl_git_pass(git_repository_set_head(repo, "refs/tags/test"));
+	cl_git_pass(git_repository_set_head(repo, "refs/remotes/test/master"));
 
-	test_reflog(repo, 3, NULL, "refs/heads/haacked", "foo@example.com", "checkout: moving from master to haacked");
-	test_reflog(repo, 2, NULL, "tags/test^{commit}", "foo@example.com", "checkout: moving from unborn to e90810b8df3e80c413d903f631643c716887138d");
-	test_reflog(repo, 1, "tags/test^{commit}", "refs/heads/haacked", "foo@example.com", "checkout: moving from e90810b8df3e80c413d903f631643c716887138d to haacked");
-	test_reflog(repo, 0, "refs/heads/haacked", "tags/test^{commit}", "foo@example.com", "checkout: moving from haacked to test");
+	test_reflog(repo, 4, NULL, "refs/heads/haacked", "foo@example.com", "checkout: moving from master to haacked");
+	test_reflog(repo, 3, NULL, "tags/test^{commit}", "foo@example.com", "checkout: moving from unborn to e90810b8df3e80c413d903f631643c716887138d");
+	test_reflog(repo, 2, "tags/test^{commit}", "refs/heads/haacked", "foo@example.com", "checkout: moving from e90810b8df3e80c413d903f631643c716887138d to haacked");
+	test_reflog(repo, 1, "refs/heads/haacked", "tags/test^{commit}", "foo@example.com", "checkout: moving from haacked to test");
+	test_reflog(repo, 0, "tags/test^{commit}", "refs/remotes/test/master", "foo@example.com", "checkout: moving from e90810b8df3e80c413d903f631643c716887138d to test/master");
 
 	cl_git_pass(git_annotated_commit_from_revspec(&annotated, repo, "haacked~0"));
 	cl_git_pass(git_repository_set_head_detached_from_annotated(repo, annotated));
 
-	test_reflog(repo, 0, NULL, "refs/heads/haacked", "foo@example.com", "checkout: moving from e90810b8df3e80c413d903f631643c716887138d to haacked~0");
+	test_reflog(repo, 0, NULL, "refs/heads/haacked", "foo@example.com", "checkout: moving from be3563ae3f795b2b4353bcce3a527ad0a4f7f644 to haacked~0");
 
 	git_annotated_commit_free(annotated);
 	git_object_free(tag);