thodg/libgit2

diff --git a/src/checkout.c b/src/checkout.c
index fa0609f..7c90ef8 100644
--- a/src/checkout.c
+++ b/src/checkout.c
@@ -851,7 +851,7 @@ static void report_progress(
 			data->opts.progress_payload);
 }
 
-static int checkout_safe_for_update_only(const char *path, mode_t expected_mode)
+int git_checkout__safe_for_update_only(const char *path, mode_t expected_mode)
 {
 	struct stat st;
 
@@ -921,7 +921,7 @@ static int checkout_blob(
 		return -1;
 
 	if ((data->strategy & GIT_CHECKOUT_UPDATE_ONLY) != 0) {
-		int rval = checkout_safe_for_update_only(
+		int rval = git_checkout__safe_for_update_only(
 			git_buf_cstr(&data->path), file->mode);
 		if (rval <= 0)
 			return rval;
diff --git a/src/checkout.h b/src/checkout.h
index 27e682f..9a80989 100644
--- a/src/checkout.h
+++ b/src/checkout.h
@@ -40,6 +40,10 @@ extern int git_checkout_iterator(
 	git_iterator *target,
 	const git_checkout_opts *opts);
 
+int git_checkout__safe_for_update_only(
+	const char *path,
+	mode_t expected_mode);
+
 int git_checkout__write_content(
 	checkout_data *data,
 	const git_oid *oid,
diff --git a/src/checkout_conflicts.c b/src/checkout_conflicts.c
index eb1ac6e..aa90647 100644
--- a/src/checkout_conflicts.c
+++ b/src/checkout_conflicts.c
@@ -410,6 +410,7 @@ static int checkout_write_entry(
 {
 	const char *hint_path = NULL, *suffix;
 	struct stat st;
+	int error;
 
 	assert (side == conflict->ours || side == conflict->theirs);
 
@@ -434,6 +435,10 @@ static int checkout_write_entry(
 		hint_path = side->path;
 	}
 
+	if ((data->strategy & GIT_CHECKOUT_UPDATE_ONLY) != 0 &&
+		(error = git_checkout__safe_for_update_only(git_buf_cstr(&data->path), side->mode)) <= 0)
+		return error;
+
 	return git_checkout__write_content(data,
 		&side->oid, git_buf_cstr(&data->path), hint_path, side->mode, &st);
 }
@@ -528,8 +533,14 @@ static int checkout_write_merge(
 		goto done;
 	}
 
-	if ((error = checkout_merge_path(&path_workdir, data, conflict, &result)) < 0 ||
-		(error = git_futils_mkpath2file(path_workdir.ptr, 0755)) < 0 ||
+	if ((error = checkout_merge_path(&path_workdir, data, conflict, &result)) < 0)
+		goto done;
+
+	if ((data->strategy & GIT_CHECKOUT_UPDATE_ONLY) != 0 &&
+		(error = git_checkout__safe_for_update_only(git_buf_cstr(&path_workdir), result.mode)) <= 0)
+		goto done;
+
+	if ((error = git_futils_mkpath2file(path_workdir.ptr, 0755)) < 0 ||
 		(error = git_filebuf_open(&output, path_workdir.ptr, GIT_FILEBUF_DO_NOT_BUFFER)) < 0 ||
 		(error = git_filebuf_write(&output, result.data, result.len)) < 0 ||
 		(error = git_filebuf_commit(&output, result.mode)) < 0)
diff --git a/tests-clar/checkout/conflict.c b/tests-clar/checkout/conflict.c
index 8b6dd4c..0b37ec8 100644
--- a/tests-clar/checkout/conflict.c
+++ b/tests-clar/checkout/conflict.c
@@ -82,7 +82,9 @@ static void create_index(struct checkout_index_entry *entries, size_t entries_le
 
 	for (i = 0; i < entries_len; i++) {
 		git_buf_joinpath(&path, TEST_REPO_PATH, entries[i].path);
-		p_unlink(git_buf_cstr(&path));
+
+		if (entries[i].stage == 3 && (i == 0 || strcmp(entries[i-1].path, entries[i].path) != 0 || entries[i-1].stage != 2))
+			p_unlink(git_buf_cstr(&path));
 
 		git_index_remove_bypath(g_index, entries[i].path);
 	}
@@ -203,6 +205,7 @@ void test_checkout_conflict__ignored(void)
 	opts.checkout_strategy |= GIT_CHECKOUT_SKIP_UNMERGED;
 
 	create_conflicting_index();
+	cl_git_pass(p_unlink(TEST_REPO_PATH "/conflicting.txt"));
 
 	cl_git_pass(git_checkout_index(g_repo, g_index, &opts));
 
@@ -974,3 +977,48 @@ void test_checkout_conflict__name_mangled_file_exists_in_workdir(void)
 	ensure_workdir("directory_file-one~ours_0", 0100644, CONFLICTING_OURS_OID);
 	ensure_workdir("directory_file-two~theirs_0", 0100644, CONFLICTING_THEIRS_OID);
 }
+
+void test_checkout_conflict__update_only(void)
+{
+	git_checkout_opts opts = GIT_CHECKOUT_OPTS_INIT;
+
+	struct checkout_index_entry checkout_index_entries[] = {
+		{ 0100644, AUTOMERGEABLE_ANCESTOR_OID, 1, "automergeable.txt" },
+		{ 0100644, AUTOMERGEABLE_OURS_OID, 2, "automergeable.txt" },
+		{ 0100644, AUTOMERGEABLE_THEIRS_OID, 3, "automergeable.txt" },
+
+		{ 0100644, CONFLICTING_ANCESTOR_OID, 1, "modify-delete" },
+		{ 0100644, CONFLICTING_THEIRS_OID, 3, "modify-delete" },
+
+		{ 0100644, CONFLICTING_ANCESTOR_OID, 1, "directory_file-one" },
+		{ 0100644, CONFLICTING_OURS_OID, 2, "directory_file-one" },
+		{ 0100644, CONFLICTING_THEIRS_OID, 0, "directory_file-one/file" },
+
+		{ 0100644, CONFLICTING_ANCESTOR_OID, 1, "directory_file-two" },
+		{ 0100644, CONFLICTING_OURS_OID, 0, "directory_file-two/file" },
+		{ 0100644, CONFLICTING_THEIRS_OID, 3, "directory_file-two" },
+	};
+
+	opts.checkout_strategy |= GIT_CHECKOUT_UPDATE_ONLY;
+
+	create_index(checkout_index_entries, 3);
+	git_index_write(g_index);
+
+	cl_git_pass(p_mkdir("merge-resolve/directory_file-two", 0777));
+	cl_git_rewritefile("merge-resolve/directory_file-two/file", CONFLICTING_OURS_FILE);
+
+	cl_git_pass(git_checkout_index(g_repo, g_index, &opts));
+
+	ensure_workdir_contents("automergeable.txt", AUTOMERGEABLE_MERGED_FILE);
+	ensure_workdir("directory_file-two/file", 0100644, CONFLICTING_OURS_OID);
+
+	cl_assert(!git_path_exists("merge-resolve/modify-delete"));
+	cl_assert(!git_path_exists("merge-resolve/test-one.txt"));
+	cl_assert(!git_path_exists("merge-resolve/test-one-side-one.txt"));
+	cl_assert(!git_path_exists("merge-resolve/test-one-side-two.txt"));
+	cl_assert(!git_path_exists("merge-resolve/test-one.txt~ours"));
+	cl_assert(!git_path_exists("merge-resolve/test-one.txt~theirs"));
+	cl_assert(!git_path_exists("merge-resolve/directory_file-one/file"));
+	cl_assert(!git_path_exists("merge-resolve/directory_file-one~ours"));
+	cl_assert(!git_path_exists("merge-resolve/directory_file-two~theirs"));
+}