merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 106 insertions, 51 deletions

diff --git a/third_party/git/builtin/clone.c b/third_party/git/builtin/clone.c
index f665b28ccccf..391aa41075ee 100644
--- a/third_party/git/builtin/clone.c
+++ b/third_party/git/builtin/clone.c
@@ -32,7 +32,6 @@
 #include "connected.h"
 #include "packfile.h"
 #include "list-objects-filter-options.h"
-#include "object-store.h"
 
 /*
  * Overall FIXMEs:
@@ -60,6 +59,7 @@ static const char *real_git_dir;
 static char *option_upload_pack = "git-upload-pack";
 static int option_verbosity;
 static int option_progress = -1;
+static int option_sparse_checkout;
 static enum transport_family family;
 static struct string_list option_config = STRING_LIST_INIT_NODUP;
 static struct string_list option_required_reference = STRING_LIST_INIT_NODUP;
@@ -102,10 +102,10 @@ static struct option builtin_clone_options[] = {
 		    N_("don't use local hardlinks, always copy")),
 	OPT_BOOL('s', "shared", &option_shared,
 		    N_("setup as shared repository")),
-	OPT_ALIAS(0, "recursive", "recurse-submodules"),
 	{ OPTION_CALLBACK, 0, "recurse-submodules", &option_recurse_submodules,
 	  N_("pathspec"), N_("initialize submodules in the clone"),
 	  PARSE_OPT_OPTARG, recurse_submodules_cb, (intptr_t)"." },
+	OPT_ALIAS(0, "recursive", "recurse-submodules"),
 	OPT_INTEGER('j', "jobs", &max_jobs,
 		    N_("number of submodules cloned in parallel")),
 	OPT_STRING(0, "template", &option_template, N_("template-directory"),
@@ -147,6 +147,8 @@ static struct option builtin_clone_options[] = {
 	OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
 	OPT_BOOL(0, "remote-submodules", &option_remote_submodules,
 		    N_("any cloned submodules will use their remote-tracking branch")),
+	OPT_BOOL(0, "sparse", &option_sparse_checkout,
+		    N_("initialize sparse-checkout file to include only files at root")),
 	OPT_END()
 };
 
@@ -418,6 +420,7 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 	struct dir_iterator *iter;
 	int iter_status;
 	unsigned int flags;
+	struct strbuf realpath = STRBUF_INIT;
 
 	mkdir_if_missing(dest->buf, 0777);
 
@@ -452,7 +455,8 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 		if (unlink(dest->buf) && errno != ENOENT)
 			die_errno(_("failed to unlink '%s'"), dest->buf);
 		if (!option_no_hardlinks) {
-			if (!link(real_path(src->buf), dest->buf))
+			strbuf_realpath(&realpath, src->buf, 1);
+			if (!link(realpath.buf, dest->buf))
 				continue;
 			if (option_local > 0)
 				die_errno(_("failed to create link '%s'"), dest->buf);
@@ -466,6 +470,8 @@ static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 		strbuf_setlen(src, src_len);
 		die(_("failed to iterate over '%s'"), src->buf);
 	}
+
+	strbuf_release(&realpath);
 }
 
 static void clone_local(const char *src_repo, const char *dest_repo)
@@ -637,7 +643,9 @@ static void write_followtags(const struct ref *refs, const char *msg)
 			continue;
 		if (ends_with(ref->name, "^{}"))
 			continue;
-		if (!has_object_file(&ref->old_oid))
+		if (!has_object_file_with_flags(&ref->old_oid,
+						OBJECT_INFO_QUICK |
+						OBJECT_INFO_SKIP_FETCH_OBJECT))
 			continue;
 		update_ref(msg, ref->name, &ref->old_oid, NULL, 0,
 			   UPDATE_REFS_DIE_ON_ERR);
@@ -670,8 +678,7 @@ static void update_remote_refs(const struct ref *refs,
 			       const char *branch_top,
 			       const char *msg,
 			       struct transport *transport,
-			       int check_connectivity,
-			       int check_refs_only)
+			       int check_connectivity)
 {
 	const struct ref *rm = mapped_refs;
 
@@ -680,7 +687,6 @@ static void update_remote_refs(const struct ref *refs,
 
 		opt.transport = transport;
 		opt.progress = transport->progress;
-		opt.check_refs_only = !!check_refs_only;
 
 		if (check_connected(iterate_ref_map, &rm, &opt))
 			die(_("remote did not send all necessary objects"));
@@ -734,6 +740,27 @@ static void update_head(const struct ref *our, const struct ref *remote,
 	}
 }
 
+static int git_sparse_checkout_init(const char *repo)
+{
+	struct strvec argv = STRVEC_INIT;
+	int result = 0;
+	strvec_pushl(&argv, "-C", repo, "sparse-checkout", "init", NULL);
+
+	/*
+	 * We must apply the setting in the current process
+	 * for the later checkout to use the sparse-checkout file.
+	 */
+	core_apply_sparse_checkout = 1;
+
+	if (run_command_v_opt(argv.v, RUN_GIT_CMD)) {
+		error(_("failed to initialize sparse-checkout"));
+		result = 1;
+	}
+
+	strvec_clear(&argv);
+	return result;
+}
+
 static int checkout(int submodule_progress)
 {
 	struct object_id oid;
@@ -756,11 +783,11 @@ static int checkout(int submodule_progress)
 	if (!strcmp(head, "HEAD")) {
 		if (advice_detached_head)
 			detach_advice(oid_to_hex(&oid));
+		FREE_AND_NULL(head);
 	} else {
 		if (!starts_with(head, "refs/heads/"))
 			die(_("HEAD not found below refs/heads!"));
 	}
-	free(head);
 
 	/* We need to be in the new work tree for the checkout */
 	setup_work_tree();
@@ -775,6 +802,7 @@ static int checkout(int submodule_progress)
 	opts.verbose_update = (option_verbosity >= 0);
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
+	init_checkout_metadata(&opts.meta, head, &oid, NULL);
 
 	tree = parse_tree_indirect(&oid);
 	parse_tree(tree);
@@ -782,35 +810,42 @@ static int checkout(int submodule_progress)
 	if (unpack_trees(1, &t, &opts) < 0)
 		die(_("unable to checkout working tree"));
 
+	free(head);
+
 	if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 		die(_("unable to write new index file"));
 
-	err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
+	err |= run_hook_le(NULL, "post-checkout", oid_to_hex(&null_oid),
 			   oid_to_hex(&oid), "1", NULL);
 
 	if (!err && (option_recurse_submodules.nr > 0)) {
-		struct argv_array args = ARGV_ARRAY_INIT;
-		argv_array_pushl(&args, "submodule", "update", "--init", "--recursive", NULL);
+		struct strvec args = STRVEC_INIT;
+		strvec_pushl(&args, "submodule", "update", "--require-init", "--recursive", NULL);
 
 		if (option_shallow_submodules == 1)
-			argv_array_push(&args, "--depth=1");
+			strvec_push(&args, "--depth=1");
 
 		if (max_jobs != -1)
-			argv_array_pushf(&args, "--jobs=%d", max_jobs);
+			strvec_pushf(&args, "--jobs=%d", max_jobs);
 
 		if (submodule_progress)
-			argv_array_push(&args, "--progress");
+			strvec_push(&args, "--progress");
 
 		if (option_verbosity < 0)
-			argv_array_push(&args, "--quiet");
+			strvec_push(&args, "--quiet");
 
 		if (option_remote_submodules) {
-			argv_array_push(&args, "--remote");
-			argv_array_push(&args, "--no-fetch");
+			strvec_push(&args, "--remote");
+			strvec_push(&args, "--no-fetch");
 		}
 
-		err = run_command_v_opt(args.argv, RUN_GIT_CMD);
-		argv_array_clear(&args);
+		if (option_single_branch >= 0)
+			strvec_push(&args, option_single_branch ?
+					       "--single-branch" :
+					       "--no-single-branch");
+
+		err = run_command_v_opt(args.v, RUN_GIT_CMD);
+		strvec_clear(&args);
 	}
 
 	return err;
@@ -900,7 +935,7 @@ static void dissociate_from_references(void)
 	free(alternates);
 }
 
-static int dir_exists(const char *path)
+static int path_exists(const char *path)
 {
 	struct stat sb;
 	return !stat(path, &sb);
@@ -910,15 +945,14 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 {
 	int is_bundle = 0, is_local;
 	const char *repo_name, *repo, *work_tree, *git_dir;
-	char *path, *dir;
-	int dest_exists;
+	char *path, *dir, *display_repo = NULL;
+	int dest_exists, real_dest_exists = 0;
 	const struct ref *refs, *remote_head;
 	const struct ref *remote_head_points_at;
 	const struct ref *our_head_points_at;
 	struct ref *mapped_refs;
 	const struct ref *ref;
 	struct strbuf key = STRBUF_INIT;
-	struct strbuf default_refspec = STRBUF_INIT;
 	struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 	struct transport *transport = NULL;
 	const char *src_ref_prefix = "refs/heads/";
@@ -926,9 +960,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	int err = 0, complete_refs_before_fetch = 1;
 	int submodule_progress;
 
-	struct argv_array ref_prefixes = ARGV_ARRAY_INIT;
-
-	fetch_if_missing = 0;
+	struct strvec ref_prefixes = STRVEC_INIT;
 
 	packet_trace_identity("clone");
 	argc = parse_options(argc, argv, prefix, builtin_clone_options,
@@ -967,10 +999,11 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	path = get_repo_path(repo_name, &is_bundle);
 	if (path)
 		repo = absolute_pathdup(repo_name);
-	else if (!strchr(repo_name, ':'))
-		die(_("repository '%s' does not exist"), repo_name);
-	else
+	else if (strchr(repo_name, ':')) {
 		repo = repo_name;
+		display_repo = transport_anonymize_url(repo);
+	} else
+		die(_("repository '%s' does not exist"), repo_name);
 
 	/* no need to be strict, transport_set_option() will validate it again */
 	if (option_depth && atoi(option_depth) < 1)
@@ -982,18 +1015,28 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		dir = guess_dir_name(repo_name, is_bundle, option_bare);
 	strip_trailing_slashes(dir);
 
-	dest_exists = dir_exists(dir);
+	dest_exists = path_exists(dir);
 	if (dest_exists && !is_empty_dir(dir))
 		die(_("destination path '%s' already exists and is not "
 			"an empty directory."), dir);
 
-	strbuf_addf(&reflog_msg, "clone: from %s", repo);
+	if (real_git_dir) {
+		real_dest_exists = path_exists(real_git_dir);
+		if (real_dest_exists && !is_empty_dir(real_git_dir))
+			die(_("repository path '%s' already exists and is not "
+				"an empty directory."), real_git_dir);
+	}
+
+
+	strbuf_addf(&reflog_msg, "clone: from %s",
+		    display_repo ? display_repo : repo);
+	free(display_repo);
 
 	if (option_bare)
 		work_tree = NULL;
 	else {
 		work_tree = getenv("GIT_WORK_TREE");
-		if (work_tree && dir_exists(work_tree))
+		if (work_tree && path_exists(work_tree))
 			die(_("working tree '%s' already exists."), work_tree);
 	}
 
@@ -1021,7 +1064,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	}
 
 	if (real_git_dir) {
-		if (dir_exists(real_git_dir))
+		if (real_dest_exists)
 			junk_git_dir_flags |= REMOVE_DIR_KEEP_TOPLEVEL;
 		junk_git_dir = real_git_dir;
 	} else {
@@ -1075,7 +1118,8 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		}
 	}
 
-	init_db(git_dir, real_git_dir, option_template, INIT_DB_QUIET);
+	init_db(git_dir, real_git_dir, option_template, GIT_HASH_UNKNOWN, NULL,
+		INIT_DB_QUIET);
 
 	if (real_git_dir)
 		git_dir = real_git_dir;
@@ -1107,11 +1151,13 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	if (option_required_reference.nr || option_optional_reference.nr)
 		setup_reference();
 
+	if (option_sparse_checkout && git_sparse_checkout_init(dir))
+		return 1;
+
 	remote = remote_get(option_origin);
 
-	strbuf_addf(&default_refspec, "+%s*:%s*", src_ref_prefix,
-		    branch_top.buf);
-	refspec_append(&remote->fetch, default_refspec.buf);
+	refspec_appendf(&remote->fetch, "+%s*:%s*", src_ref_prefix,
+			branch_top.buf);
 
 	transport = transport_get(remote, remote->url[0]);
 	transport_set_verbosity(transport, option_verbosity, option_progress);
@@ -1160,29 +1206,36 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		transport->server_options = &server_options;
 
 	if (filter_options.choice) {
-		struct strbuf expanded_filter_spec = STRBUF_INIT;
-		expand_list_objects_filter_spec(&filter_options,
-						&expanded_filter_spec);
+		const char *spec =
+			expand_list_objects_filter_spec(&filter_options);
 		transport_set_option(transport, TRANS_OPT_LIST_OBJECTS_FILTER,
-				     expanded_filter_spec.buf);
+				     spec);
 		transport_set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
-		strbuf_release(&expanded_filter_spec);
 	}
 
 	if (transport->smart_options && !deepen && !filter_options.choice)
 		transport->smart_options->check_self_contained_and_connected = 1;
 
 
-	argv_array_push(&ref_prefixes, "HEAD");
+	strvec_push(&ref_prefixes, "HEAD");
 	refspec_ref_prefixes(&remote->fetch, &ref_prefixes);
 	if (option_branch)
 		expand_ref_prefix(&ref_prefixes, option_branch);
 	if (!option_no_tags)
-		argv_array_push(&ref_prefixes, "refs/tags/");
+		strvec_push(&ref_prefixes, "refs/tags/");
 
 	refs = transport_get_remote_refs(transport, &ref_prefixes);
 
 	if (refs) {
+		int hash_algo = hash_algo_by_ptr(transport_get_hash_algo(transport));
+
+		/*
+		 * Now that we know what algorithm the remote side is using,
+		 * let's set ours to the same thing.
+		 */
+		initialize_repository_version(hash_algo, 1);
+		repo_set_hash_algo(the_repository, hash_algo);
+
 		mapped_refs = wanted_peer_refs(refs, &remote->fetch);
 		/*
 		 * transport_get_remote_refs() may return refs with null sha-1
@@ -1229,9 +1282,13 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 		remote_head_points_at = NULL;
 		remote_head = NULL;
 		option_no_checkout = 1;
-		if (!option_bare)
-			install_branch_config(0, "master", option_origin,
-					      "refs/heads/master");
+		if (!option_bare) {
+			const char *branch = git_default_branch_name();
+			char *ref = xstrfmt("refs/heads/%s", branch);
+
+			install_branch_config(0, branch, option_origin, ref);
+			free(ref);
+		}
 	}
 
 	write_refspec_config(src_ref_prefix, our_head_points_at,
@@ -1247,7 +1304,7 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
 	update_remote_refs(refs, mapped_refs, remote_head_points_at,
 			   branch_top.buf, reflog_msg.buf, transport,
-			   !is_local, filter_options.choice);
+			   !is_local);
 
 	update_head(our_head_points_at, remote_head, reflog_msg.buf);
 
@@ -1268,15 +1325,13 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 	}
 
 	junk_mode = JUNK_LEAVE_REPO;
-	fetch_if_missing = 1;
 	err = checkout(submodule_progress);
 
 	strbuf_release(&reflog_msg);
 	strbuf_release(&branch_top);
 	strbuf_release(&key);
-	strbuf_release(&default_refspec);
 	junk_mode = JUNK_LEAVE_ALL;
 
-	argv_array_clear(&ref_prefixes);
+	strvec_clear(&ref_prefixes);
 	return err;
 }