1 files changed, 655 insertions, 0 deletions
diff --git a/src/libgit2/clone.c b/src/libgit2/clone.c
new file mode 100644
index 000000000..1843875f8
--- /dev/null
+++ b/src/libgit2/clone.c
@@ -0,0 +1,655 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "clone.h"
+
+#include "git2/clone.h"
+#include "git2/remote.h"
+#include "git2/revparse.h"
+#include "git2/branch.h"
+#include "git2/config.h"
+#include "git2/checkout.h"
+#include "git2/commit.h"
+#include "git2/tree.h"
+
+#include "remote.h"
+#include "futils.h"
+#include "refs.h"
+#include "fs_path.h"
+#include "repository.h"
+#include "odb.h"
+
+static int clone_local_into(git_repository *repo, git_remote *remote, const git_fetch_options *fetch_opts, const git_checkout_options *co_opts, const char *branch, int link);
+
+static int create_branch(
+	git_reference **branch,
+	git_repository *repo,
+	const git_oid *target,
+	const char *name,
+	const char *log_message)
+{
+	git_commit *head_obj = NULL;
+	git_reference *branch_ref = NULL;
+	git_str refname = GIT_STR_INIT;
+	int error;
+
+	/* Find the target commit */
+	if ((error = git_commit_lookup(&head_obj, repo, target)) < 0)
+		return error;
+
+	/* Create the new branch */
+	if ((error = git_str_printf(&refname, GIT_REFS_HEADS_DIR "%s", name)) < 0)
+		return error;
+
+	error = git_reference_create(&branch_ref, repo, git_str_cstr(&refname), target, 0, log_message);
+	git_str_dispose(&refname);
+	git_commit_free(head_obj);
+
+	if (!error)
+		*branch = branch_ref;
+	else
+		git_reference_free(branch_ref);
+
+	return error;
+}
+
+static int setup_tracking_config(
+	git_repository *repo,
+	const char *branch_name,
+	const char *remote_name,
+	const char *merge_target)
+{
+	git_config *cfg;
+	git_str remote_key = GIT_STR_INIT, merge_key = GIT_STR_INIT;
+	int error = -1;
+
+	if (git_repository_config__weakptr(&cfg, repo) < 0)
+		return -1;
+
+	if (git_str_printf(&remote_key, "branch.%s.remote", branch_name) < 0)
+		goto cleanup;
+
+	if (git_str_printf(&merge_key, "branch.%s.merge", branch_name) < 0)
+		goto cleanup;
+
+	if (git_config_set_string(cfg, git_str_cstr(&remote_key), remote_name) < 0)
+		goto cleanup;
+
+	if (git_config_set_string(cfg, git_str_cstr(&merge_key), merge_target) < 0)
+		goto cleanup;
+
+	error = 0;
+
+cleanup:
+	git_str_dispose(&remote_key);
+	git_str_dispose(&merge_key);
+	return error;
+}
+
+static int create_tracking_branch(
+	git_reference **branch,
+	git_repository *repo,
+	const git_oid *target,
+	const char *branch_name,
+	const char *log_message)
+{
+	int error;
+
+	if ((error = create_branch(branch, repo, target, branch_name, log_message)) < 0)
+		return error;
+
+	return setup_tracking_config(
+		repo,
+		branch_name,
+		GIT_REMOTE_ORIGIN,
+		git_reference_name(*branch));
+}
+
+static int update_head_to_new_branch(
+	git_repository *repo,
+	const git_oid *target,
+	const char *name,
+	const char *reflog_message)
+{
+	git_reference *tracking_branch = NULL;
+	int error;
+
+	if (!git__prefixcmp(name, GIT_REFS_HEADS_DIR))
+		name += strlen(GIT_REFS_HEADS_DIR);
+
+	error = create_tracking_branch(&tracking_branch, repo, target, name,
+			reflog_message);
+
+	if (!error)
+		error = git_repository_set_head(
+			repo, git_reference_name(tracking_branch));
+
+	git_reference_free(tracking_branch);
+
+	/* if it already existed, then the user's refspec created it for us, ignore it' */
+	if (error == GIT_EEXISTS)
+		error = 0;
+
+	return error;
+}
+
+static int update_head_to_default(git_repository *repo)
+{
+	git_str initialbranch = GIT_STR_INIT;
+	const char *branch_name;
+	int error = 0;
+
+	if ((error = git_repository_initialbranch(&initialbranch, repo)) < 0)
+		goto done;
+
+	if (git__prefixcmp(initialbranch.ptr, GIT_REFS_HEADS_DIR) != 0) {
+		git_error_set(GIT_ERROR_INVALID, "invalid initial branch '%s'", initialbranch.ptr);
+		error = -1;
+		goto done;
+	}
+
+	branch_name = initialbranch.ptr + strlen(GIT_REFS_HEADS_DIR);
+
+	error = setup_tracking_config(repo, branch_name, GIT_REMOTE_ORIGIN,
+		initialbranch.ptr);
+
+done:
+	git_str_dispose(&initialbranch);
+	return error;
+}
+
+static int update_remote_head(
+	git_repository *repo,
+	git_remote *remote,
+	git_str *target,
+	const char *reflog_message)
+{
+	git_refspec *refspec;
+	git_reference *remote_head = NULL;
+	git_str remote_head_name = GIT_STR_INIT;
+	git_str remote_branch_name = GIT_STR_INIT;
+	int error;
+
+	/* Determine the remote tracking ref name from the local branch */
+	refspec = git_remote__matching_refspec(remote, git_str_cstr(target));
+
+	if (refspec == NULL) {
+		git_error_set(GIT_ERROR_NET, "the remote's default branch does not fit the refspec configuration");
+		error = GIT_EINVALIDSPEC;
+		goto cleanup;
+	}
+
+	if ((error = git_refspec__transform(
+		&remote_branch_name,
+		refspec,
+		git_str_cstr(target))) < 0)
+		goto cleanup;
+
+	if ((error = git_str_printf(&remote_head_name,
+		"%s%s/%s",
+		GIT_REFS_REMOTES_DIR,
+		git_remote_name(remote),
+		GIT_HEAD_FILE)) < 0)
+		goto cleanup;
+
+	error = git_reference_symbolic_create(
+		&remote_head,
+		repo,
+		git_str_cstr(&remote_head_name),
+		git_str_cstr(&remote_branch_name),
+		true,
+		reflog_message);
+
+cleanup:
+	git_reference_free(remote_head);
+	git_str_dispose(&remote_branch_name);
+	git_str_dispose(&remote_head_name);
+	return error;
+}
+
+static int update_head_to_remote(
+		git_repository *repo,
+		git_remote *remote,
+		const char *reflog_message)
+{
+	int error = 0;
+	size_t refs_len;
+	const git_remote_head *remote_head, **refs;
+	const git_oid *remote_head_id;
+	git_str branch = GIT_STR_INIT;
+
+	if ((error = git_remote_ls(&refs, &refs_len, remote)) < 0)
+		return error;
+
+	/* We cloned an empty repository or one with an unborn HEAD */
+	if (refs_len == 0 || strcmp(refs[0]->name, GIT_HEAD_FILE))
+		return update_head_to_default(repo);
+
+	/* We know we have HEAD, let's see where it points */
+	remote_head = refs[0];
+	GIT_ASSERT(remote_head);
+
+	remote_head_id = &remote_head->oid;
+
+	error = git_remote__default_branch(&branch, remote);
+	if (error == GIT_ENOTFOUND) {
+		error = git_repository_set_head_detached(
+			repo, remote_head_id);
+		goto cleanup;
+	}
+
+	if ((error = update_remote_head(repo, remote, &branch, reflog_message)) < 0)
+		goto cleanup;
+
+	error = update_head_to_new_branch(
+		repo,
+		remote_head_id,
+		git_str_cstr(&branch),
+		reflog_message);
+
+cleanup:
+	git_str_dispose(&branch);
+
+	return error;
+}
+
+static int update_head_to_branch(
+		git_repository *repo,
+		git_remote *remote,
+		const char *branch,
+		const char *reflog_message)
+{
+	int retcode;
+	git_str remote_branch_name = GIT_STR_INIT;
+	git_reference *remote_ref = NULL;
+	git_str default_branch = GIT_STR_INIT;
+
+	GIT_ASSERT_ARG(remote);
+	GIT_ASSERT_ARG(branch);
+
+	if ((retcode = git_str_printf(&remote_branch_name, GIT_REFS_REMOTES_DIR "%s/%s",
+		git_remote_name(remote), branch)) < 0 )
+		goto cleanup;
+
+	if ((retcode = git_reference_lookup(&remote_ref, repo, git_str_cstr(&remote_branch_name))) < 0)
+		goto cleanup;
+
+	if ((retcode = update_head_to_new_branch(repo, git_reference_target(remote_ref), branch,
+			reflog_message)) < 0)
+		goto cleanup;
+
+	if ((retcode = git_remote__default_branch(&default_branch, remote)) < 0)
+		goto cleanup;
+
+	if (!git_remote__matching_refspec(remote, git_str_cstr(&default_branch)))
+		goto cleanup;
+
+	retcode = update_remote_head(repo, remote, &default_branch, reflog_message);
+
+cleanup:
+	git_reference_free(remote_ref);
+	git_str_dispose(&remote_branch_name);
+	git_str_dispose(&default_branch);
+	return retcode;
+}
+
+static int default_repository_create(git_repository **out, const char *path, int bare, void *payload)
+{
+	GIT_UNUSED(payload);
+
+	return git_repository_init(out, path, bare);
+}
+
+static int default_remote_create(
+		git_remote **out,
+		git_repository *repo,
+		const char *name,
+		const char *url,
+		void *payload)
+{
+	GIT_UNUSED(payload);
+
+	return git_remote_create(out, repo, name, url);
+}
+
+/*
+ * submodules?
+ */
+
+static int create_and_configure_origin(
+		git_remote **out,
+		git_repository *repo,
+		const char *url,
+		const git_clone_options *options)
+{
+	int error;
+	git_remote *origin = NULL;
+	char buf[GIT_PATH_MAX];
+	git_remote_create_cb remote_create = options->remote_cb;
+	void *payload = options->remote_cb_payload;
+
+	/* If the path exists and is a dir, the url should be the absolute path */
+	if (git_fs_path_root(url) < 0 && git_fs_path_exists(url) && git_fs_path_isdir(url)) {
+		if (p_realpath(url, buf) == NULL)
+			return -1;
+
+		url = buf;
+	}
+
+	if (!remote_create) {
+		remote_create = default_remote_create;
+		payload = NULL;
+	}
+
+	if ((error = remote_create(&origin, repo, "origin", url, payload)) < 0)
+		goto on_error;
+
+	*out = origin;
+	return 0;
+
+on_error:
+	git_remote_free(origin);
+	return error;
+}
+
+static bool should_checkout(
+	git_repository *repo,
+	bool is_bare,
+	const git_checkout_options *opts)
+{
+	if (is_bare)
+		return false;
+
+	if (!opts)
+		return false;
+
+	if (opts->checkout_strategy == GIT_CHECKOUT_NONE)
+		return false;
+
+	return !git_repository_head_unborn(repo);
+}
+
+static int checkout_branch(git_repository *repo, git_remote *remote, const git_checkout_options *co_opts, const char *branch, const char *reflog_message)
+{
+	int error;
+
+	if (branch)
+		error = update_head_to_branch(repo, remote, branch, reflog_message);
+	/* Point HEAD to the same ref as the remote's head */
+	else
+		error = update_head_to_remote(repo, remote, reflog_message);
+
+	if (!error && should_checkout(repo, git_repository_is_bare(repo), co_opts))
+		error = git_checkout_head(repo, co_opts);
+
+	return error;
+}
+
+static int clone_into(git_repository *repo, git_remote *_remote, const git_fetch_options *opts, const git_checkout_options *co_opts, const char *branch)
+{
+	int error;
+	git_str reflog_message = GIT_STR_INIT;
+	git_fetch_options fetch_opts;
+	git_remote *remote;
+
+	GIT_ASSERT_ARG(repo);
+	GIT_ASSERT_ARG(_remote);
+
+	if (!git_repository_is_empty(repo)) {
+		git_error_set(GIT_ERROR_INVALID, "the repository is not empty");
+		return -1;
+	}
+
+	if ((error = git_remote_dup(&remote, _remote)) < 0)
+		return error;
+
+	memcpy(&fetch_opts, opts, sizeof(git_fetch_options));
+	fetch_opts.update_fetchhead = 0;
+	fetch_opts.download_tags = GIT_REMOTE_DOWNLOAD_TAGS_ALL;
+	git_str_printf(&reflog_message, "clone: from %s", git_remote_url(remote));
+
+	if ((error = git_remote_fetch(remote, NULL, &fetch_opts, git_str_cstr(&reflog_message))) != 0)
+		goto cleanup;
+
+	error = checkout_branch(repo, remote, co_opts, branch, git_str_cstr(&reflog_message));
+
+cleanup:
+	git_remote_free(remote);
+	git_str_dispose(&reflog_message);
+
+	return error;
+}
+
+int git_clone__should_clone_local(const char *url_or_path, git_clone_local_t local)
+{
+	git_str fromurl = GIT_STR_INIT;
+	const char *path = url_or_path;
+	bool is_url, is_local;
+
+	if (local == GIT_CLONE_NO_LOCAL)
+		return 0;
+
+	if ((is_url = git_fs_path_is_local_file_url(url_or_path)) != 0) {
+		if (git_fs_path_fromurl(&fromurl, url_or_path) < 0) {
+			is_local = -1;
+			goto done;
+		}
+
+		path = fromurl.ptr;
+	}
+
+	is_local = (!is_url || local != GIT_CLONE_LOCAL_AUTO) &&
+		git_fs_path_isdir(path);
+
+done:
+	git_str_dispose(&fromurl);
+	return is_local;
+}
+
+static int git__clone(
+	git_repository **out,
+	const char *url,
+	const char *local_path,
+	const git_clone_options *_options,
+	int use_existing)
+{
+	int error = 0;
+	git_repository *repo = NULL;
+	git_remote *origin;
+	git_clone_options options = GIT_CLONE_OPTIONS_INIT;
+	uint32_t rmdir_flags = GIT_RMDIR_REMOVE_FILES;
+	git_repository_create_cb repository_cb;
+
+	GIT_ASSERT_ARG(out);
+	GIT_ASSERT_ARG(url);
+	GIT_ASSERT_ARG(local_path);
+
+	if (_options)
+		memcpy(&options, _options, sizeof(git_clone_options));
+
+	GIT_ERROR_CHECK_VERSION(&options, GIT_CLONE_OPTIONS_VERSION, "git_clone_options");
+
+	/* Only clone to a new directory or an empty directory */
+	if (git_fs_path_exists(local_path) && !use_existing && !git_fs_path_is_empty_dir(local_path)) {
+		git_error_set(GIT_ERROR_INVALID,
+			"'%s' exists and is not an empty directory", local_path);
+		return GIT_EEXISTS;
+	}
+
+	/* Only remove the root directory on failure if we create it */
+	if (git_fs_path_exists(local_path))
+		rmdir_flags |= GIT_RMDIR_SKIP_ROOT;
+
+	if (options.repository_cb)
+		repository_cb = options.repository_cb;
+	else
+		repository_cb = default_repository_create;
+
+	if ((error = repository_cb(&repo, local_path, options.bare, options.repository_cb_payload)) < 0)
+		return error;
+
+	if (!(error = create_and_configure_origin(&origin, repo, url, &options))) {
+		int clone_local = git_clone__should_clone_local(url, options.local);
+		int link = options.local != GIT_CLONE_LOCAL_NO_LINKS;
+
+		if (clone_local == 1)
+			error = clone_local_into(
+				repo, origin, &options.fetch_opts, &options.checkout_opts,
+				options.checkout_branch, link);
+		else if (clone_local == 0)
+			error = clone_into(
+				repo, origin, &options.fetch_opts, &options.checkout_opts,
+				options.checkout_branch);
+		else
+			error = -1;
+
+		git_remote_free(origin);
+	}
+
+	if (error != 0) {
+		git_error_state last_error = {0};
+		git_error_state_capture(&last_error, error);
+
+		git_repository_free(repo);
+		repo = NULL;
+
+		(void)git_futils_rmdir_r(local_path, NULL, rmdir_flags);
+
+		git_error_state_restore(&last_error);
+	}
+
+	*out = repo;
+	return error;
+}
+
+int git_clone(
+	git_repository **out,
+	const char *url,
+	const char *local_path,
+	const git_clone_options *_options)
+{
+	return git__clone(out, url, local_path, _options, 0);
+}
+
+int git_clone__submodule(
+	git_repository **out,
+	const char *url,
+	const char *local_path,
+	const git_clone_options *_options)
+{
+	return git__clone(out, url, local_path, _options, 1);
+}
+
+int git_clone_options_init(git_clone_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_clone_options, GIT_CLONE_OPTIONS_INIT);
+	return 0;
+}
+
+#ifndef GIT_DEPRECATE_HARD
+int git_clone_init_options(git_clone_options *opts, unsigned int version)
+{
+	return git_clone_options_init(opts, version);
+}
+#endif
+
+static bool can_link(const char *src, const char *dst, int link)
+{
+#ifdef GIT_WIN32
+	GIT_UNUSED(src);
+	GIT_UNUSED(dst);
+	GIT_UNUSED(link);
+	return false;
+#else
+
+	struct stat st_src, st_dst;
+
+	if (!link)
+		return false;
+
+	if (p_stat(src, &st_src) < 0)
+		return false;
+
+	if (p_stat(dst, &st_dst) < 0)
+		return false;
+
+	return st_src.st_dev == st_dst.st_dev;
+#endif
+}
+
+static int clone_local_into(git_repository *repo, git_remote *remote, const git_fetch_options *fetch_opts, const git_checkout_options *co_opts, const char *branch, int link)
+{
+	int error, flags;
+	git_repository *src;
+	git_str src_odb = GIT_STR_INIT, dst_odb = GIT_STR_INIT, src_path = GIT_STR_INIT;
+	git_str reflog_message = GIT_STR_INIT;
+
+	GIT_ASSERT_ARG(repo);
+	GIT_ASSERT_ARG(remote);
+
+	if (!git_repository_is_empty(repo)) {
+		git_error_set(GIT_ERROR_INVALID, "the repository is not empty");
+		return -1;
+	}
+
+	/*
+	 * Let's figure out what path we should use for the source
+	 * repo, if it's not rooted, the path should be relative to
+	 * the repository's worktree/gitdir.
+	 */
+	if ((error = git_fs_path_from_url_or_path(&src_path, git_remote_url(remote))) < 0)
+		return error;
+
+	/* Copy .git/objects/ from the source to the target */
+	if ((error = git_repository_open(&src, git_str_cstr(&src_path))) < 0) {
+		git_str_dispose(&src_path);
+		return error;
+	}
+
+	if (git_repository__item_path(&src_odb, src, GIT_REPOSITORY_ITEM_OBJECTS) < 0 ||
+	    git_repository__item_path(&dst_odb, repo, GIT_REPOSITORY_ITEM_OBJECTS) < 0) {
+		error = -1;
+		goto cleanup;
+	}
+
+	flags = 0;
+	if (can_link(git_repository_path(src), git_repository_path(repo), link))
+		flags |= GIT_CPDIR_LINK_FILES;
+
+	error = git_futils_cp_r(git_str_cstr(&src_odb), git_str_cstr(&dst_odb),
+				flags, GIT_OBJECT_DIR_MODE);
+
+	/*
+	 * can_link() doesn't catch all variations, so if we hit an
+	 * error and did want to link, let's try again without trying
+	 * to link.
+	 */
+	if (error < 0 && link) {
+		flags &= ~GIT_CPDIR_LINK_FILES;
+		error = git_futils_cp_r(git_str_cstr(&src_odb), git_str_cstr(&dst_odb),
+					flags, GIT_OBJECT_DIR_MODE);
+	}
+
+	if (error < 0)
+		goto cleanup;
+
+	git_str_printf(&reflog_message, "clone: from %s", git_remote_url(remote));
+
+	if ((error = git_remote_fetch(remote, NULL, fetch_opts, git_str_cstr(&reflog_message))) != 0)
+		goto cleanup;
+
+	error = checkout_branch(repo, remote, co_opts, branch, git_str_cstr(&reflog_message));
+
+cleanup:
+	git_str_dispose(&reflog_message);
+	git_str_dispose(&src_path);
+	git_str_dispose(&src_odb);
+	git_str_dispose(&dst_odb);
+	git_repository_free(src);
+	return error;
+}