Adding upstream version 1:2.43.0.upstream/1%2.43.0

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1048 insertions, 0 deletions

diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
new file mode 100644
index 0000000..5c8ffb1
--- /dev/null
+++ b/builtin/sparse-checkout.c
@@ -0,0 +1,1048 @@
+#include "builtin.h"
+#include "config.h"
+#include "dir.h"
+#include "environment.h"
+#include "gettext.h"
+#include "object-file.h"
+#include "object-name.h"
+#include "parse-options.h"
+#include "pathspec.h"
+#include "repository.h"
+#include "run-command.h"
+#include "strbuf.h"
+#include "string-list.h"
+#include "cache-tree.h"
+#include "lockfile.h"
+#include "resolve-undo.h"
+#include "unpack-trees.h"
+#include "wt-status.h"
+#include "quote.h"
+#include "setup.h"
+#include "sparse-index.h"
+#include "worktree.h"
+
+static const char *empty_base = "";
+
+static char const * const builtin_sparse_checkout_usage[] = {
+	N_("git sparse-checkout (init | list | set | add | reapply | disable | check-rules) [<options>]"),
+	NULL
+};
+
+static void write_patterns_to_file(FILE *fp, struct pattern_list *pl)
+{
+	int i;
+
+	for (i = 0; i < pl->nr; i++) {
+		struct path_pattern *p = pl->patterns[i];
+
+		if (p->flags & PATTERN_FLAG_NEGATIVE)
+			fprintf(fp, "!");
+
+		fprintf(fp, "%s", p->pattern);
+
+		if (p->flags & PATTERN_FLAG_MUSTBEDIR)
+			fprintf(fp, "/");
+
+		fprintf(fp, "\n");
+	}
+}
+
+static char const * const builtin_sparse_checkout_list_usage[] = {
+	"git sparse-checkout list",
+	NULL
+};
+
+static int sparse_checkout_list(int argc, const char **argv, const char *prefix)
+{
+	static struct option builtin_sparse_checkout_list_options[] = {
+		OPT_END(),
+	};
+	struct pattern_list pl;
+	char *sparse_filename;
+	int res;
+
+	setup_work_tree();
+	if (!core_apply_sparse_checkout)
+		die(_("this worktree is not sparse"));
+
+	argc = parse_options(argc, argv, prefix,
+			     builtin_sparse_checkout_list_options,
+			     builtin_sparse_checkout_list_usage, 0);
+
+	memset(&pl, 0, sizeof(pl));
+
+	pl.use_cone_patterns = core_sparse_checkout_cone;
+
+	sparse_filename = get_sparse_checkout_filename();
+	res = add_patterns_from_file_to_list(sparse_filename, "", 0, &pl, NULL, 0);
+	free(sparse_filename);
+
+	if (res < 0) {
+		warning(_("this worktree is not sparse (sparse-checkout file may not exist)"));
+		return 0;
+	}
+
+	if (pl.use_cone_patterns) {
+		int i;
+		struct pattern_entry *pe;
+		struct hashmap_iter iter;
+		struct string_list sl = STRING_LIST_INIT_DUP;
+
+		hashmap_for_each_entry(&pl.recursive_hashmap, &iter, pe, ent) {
+			/* pe->pattern starts with "/", skip it */
+			string_list_insert(&sl, pe->pattern + 1);
+		}
+
+		string_list_sort(&sl);
+
+		for (i = 0; i < sl.nr; i++) {
+			quote_c_style(sl.items[i].string, NULL, stdout, 0);
+			printf("\n");
+		}
+
+		return 0;
+	}
+
+	write_patterns_to_file(stdout, &pl);
+	clear_pattern_list(&pl);
+
+	return 0;
+}
+
+static void clean_tracked_sparse_directories(struct repository *r)
+{
+	int i, was_full = 0;
+	struct strbuf path = STRBUF_INIT;
+	size_t pathlen;
+	struct string_list_item *item;
+	struct string_list sparse_dirs = STRING_LIST_INIT_DUP;
+
+	/*
+	 * If we are not using cone mode patterns, then we cannot
+	 * delete directories outside of the sparse cone.
+	 */
+	if (!r || !r->index || !r->worktree)
+		return;
+	if (init_sparse_checkout_patterns(r->index) ||
+	    !r->index->sparse_checkout_patterns->use_cone_patterns)
+		return;
+
+	/*
+	 * Use the sparse index as a data structure to assist finding
+	 * directories that are safe to delete. This conversion to a
+	 * sparse index will not delete directories that contain
+	 * conflicted entries or submodules.
+	 */
+	if (r->index->sparse_index == INDEX_EXPANDED) {
+		/*
+		 * If something, such as a merge conflict or other concern,
+		 * prevents us from converting to a sparse index, then do
+		 * not try deleting files.
+		 */
+		if (convert_to_sparse(r->index, SPARSE_INDEX_MEMORY_ONLY))
+			return;
+		was_full = 1;
+	}
+
+	strbuf_addstr(&path, r->worktree);
+	strbuf_complete(&path, '/');
+	pathlen = path.len;
+
+	/*
+	 * Collect directories that have gone out of scope but also
+	 * exist on disk, so there is some work to be done. We need to
+	 * store the entries in a list before exploring, since that might
+	 * expand the sparse-index again.
+	 */
+	for (i = 0; i < r->index->cache_nr; i++) {
+		struct cache_entry *ce = r->index->cache[i];
+
+		if (S_ISSPARSEDIR(ce->ce_mode) &&
+		    repo_file_exists(r, ce->name))
+			string_list_append(&sparse_dirs, ce->name);
+	}
+
+	for_each_string_list_item(item, &sparse_dirs) {
+		struct dir_struct dir = DIR_INIT;
+		struct pathspec p = { 0 };
+		struct strvec s = STRVEC_INIT;
+
+		strbuf_setlen(&path, pathlen);
+		strbuf_addstr(&path, item->string);
+
+		dir.flags |= DIR_SHOW_IGNORED_TOO;
+
+		setup_standard_excludes(&dir);
+		strvec_push(&s, path.buf);
+
+		parse_pathspec(&p, PATHSPEC_GLOB, 0, NULL, s.v);
+		fill_directory(&dir, r->index, &p);
+
+		if (dir.nr) {
+			warning(_("directory '%s' contains untracked files,"
+				  " but is not in the sparse-checkout cone"),
+				item->string);
+		} else if (remove_dir_recursively(&path, 0)) {
+			/*
+			 * Removal is "best effort". If something blocks
+			 * the deletion, then continue with a warning.
+			 */
+			warning(_("failed to remove directory '%s'"),
+				item->string);
+		}
+
+		strvec_clear(&s);
+		clear_pathspec(&p);
+		dir_clear(&dir);
+	}
+
+	string_list_clear(&sparse_dirs, 0);
+	strbuf_release(&path);
+
+	if (was_full)
+		ensure_full_index(r->index);
+}
+
+static int update_working_directory(struct pattern_list *pl)
+{
+	enum update_sparsity_result result;
+	struct unpack_trees_options o;
+	struct lock_file lock_file = LOCK_INIT;
+	struct repository *r = the_repository;
+
+	/* If no branch has been checked out, there are no updates to make. */
+	if (is_index_unborn(r->index))
+		return UPDATE_SPARSITY_SUCCESS;
+
+	r->index->sparse_checkout_patterns = pl;
+
+	memset(&o, 0, sizeof(o));
+	o.verbose_update = isatty(2);
+	o.update = 1;
+	o.head_idx = -1;
+	o.src_index = r->index;
+	o.dst_index = r->index;
+	o.skip_sparse_checkout = 0;
+
+	setup_work_tree();
+
+	repo_hold_locked_index(r, &lock_file, LOCK_DIE_ON_ERROR);
+
+	setup_unpack_trees_porcelain(&o, "sparse-checkout");
+	result = update_sparsity(&o, pl);
+	clear_unpack_trees_porcelain(&o);
+
+	if (result == UPDATE_SPARSITY_WARNINGS)
+		/*
+		 * We don't do any special handling of warnings from untracked
+		 * files in the way or dirty entries that can't be removed.
+		 */
+		result = UPDATE_SPARSITY_SUCCESS;
+	if (result == UPDATE_SPARSITY_SUCCESS)
+		write_locked_index(r->index, &lock_file, COMMIT_LOCK);
+	else
+		rollback_lock_file(&lock_file);
+
+	clean_tracked_sparse_directories(r);
+
+	r->index->sparse_checkout_patterns = NULL;
+	return result;
+}
+
+static char *escaped_pattern(char *pattern)
+{
+	char *p = pattern;
+	struct strbuf final = STRBUF_INIT;
+
+	while (*p) {
+		if (is_glob_special(*p))
+			strbuf_addch(&final, '\\');
+
+		strbuf_addch(&final, *p);
+		p++;
+	}
+
+	return strbuf_detach(&final, NULL);
+}
+
+static void write_cone_to_file(FILE *fp, struct pattern_list *pl)
+{
+	int i;
+	struct pattern_entry *pe;
+	struct hashmap_iter iter;
+	struct string_list sl = STRING_LIST_INIT_DUP;
+	struct strbuf parent_pattern = STRBUF_INIT;
+
+	hashmap_for_each_entry(&pl->parent_hashmap, &iter, pe, ent) {
+		if (hashmap_get_entry(&pl->recursive_hashmap, pe, ent, NULL))
+			continue;
+
+		if (!hashmap_contains_parent(&pl->recursive_hashmap,
+					     pe->pattern,
+					     &parent_pattern))
+			string_list_insert(&sl, pe->pattern);
+	}
+
+	string_list_sort(&sl);
+	string_list_remove_duplicates(&sl, 0);
+
+	fprintf(fp, "/*\n!/*/\n");
+
+	for (i = 0; i < sl.nr; i++) {
+		char *pattern = escaped_pattern(sl.items[i].string);
+
+		if (strlen(pattern))
+			fprintf(fp, "%s/\n!%s/*/\n", pattern, pattern);
+		free(pattern);
+	}
+
+	string_list_clear(&sl, 0);
+
+	hashmap_for_each_entry(&pl->recursive_hashmap, &iter, pe, ent) {
+		if (!hashmap_contains_parent(&pl->recursive_hashmap,
+					     pe->pattern,
+					     &parent_pattern))
+			string_list_insert(&sl, pe->pattern);
+	}
+
+	strbuf_release(&parent_pattern);
+
+	string_list_sort(&sl);
+	string_list_remove_duplicates(&sl, 0);
+
+	for (i = 0; i < sl.nr; i++) {
+		char *pattern = escaped_pattern(sl.items[i].string);
+		fprintf(fp, "%s/\n", pattern);
+		free(pattern);
+	}
+}
+
+static int write_patterns_and_update(struct pattern_list *pl)
+{
+	char *sparse_filename;
+	FILE *fp;
+	int fd;
+	struct lock_file lk = LOCK_INIT;
+	int result;
+
+	sparse_filename = get_sparse_checkout_filename();
+
+	if (safe_create_leading_directories(sparse_filename))
+		die(_("failed to create directory for sparse-checkout file"));
+
+	fd = hold_lock_file_for_update(&lk, sparse_filename,
+				      LOCK_DIE_ON_ERROR);
+	free(sparse_filename);
+
+	result = update_working_directory(pl);
+	if (result) {
+		rollback_lock_file(&lk);
+		clear_pattern_list(pl);
+		update_working_directory(NULL);
+		return result;
+	}
+
+	fp = xfdopen(fd, "w");
+
+	if (core_sparse_checkout_cone)
+		write_cone_to_file(fp, pl);
+	else
+		write_patterns_to_file(fp, pl);
+
+	fflush(fp);
+	commit_lock_file(&lk);
+
+	clear_pattern_list(pl);
+
+	return 0;
+}
+
+enum sparse_checkout_mode {
+	MODE_NO_PATTERNS = 0,
+	MODE_ALL_PATTERNS = 1,
+	MODE_CONE_PATTERNS = 2,
+};
+
+static int set_config(enum sparse_checkout_mode mode)
+{
+	/* Update to use worktree config, if not already. */
+	if (init_worktree_config(the_repository)) {
+		error(_("failed to initialize worktree config"));
+		return 1;
+	}
+
+	if (repo_config_set_worktree_gently(the_repository,
+					    "core.sparseCheckout",
+					    mode ? "true" : "false") ||
+	    repo_config_set_worktree_gently(the_repository,
+					    "core.sparseCheckoutCone",
+					    mode == MODE_CONE_PATTERNS ?
+						"true" : "false"))
+		return 1;
+
+	if (mode == MODE_NO_PATTERNS)
+		return set_sparse_index_config(the_repository, 0);
+
+	return 0;
+}
+
+static enum sparse_checkout_mode update_cone_mode(int *cone_mode) {
+	/* If not specified, use previous definition of cone mode */
+	if (*cone_mode == -1 && core_apply_sparse_checkout)
+		*cone_mode = core_sparse_checkout_cone;
+
+	/* Set cone/non-cone mode appropriately */
+	core_apply_sparse_checkout = 1;
+	if (*cone_mode == 1 || *cone_mode == -1) {
+		core_sparse_checkout_cone = 1;
+		return MODE_CONE_PATTERNS;
+	}
+	core_sparse_checkout_cone = 0;
+	return MODE_ALL_PATTERNS;
+}
+
+static int update_modes(int *cone_mode, int *sparse_index)
+{
+	int mode, record_mode;
+
+	/* Determine if we need to record the mode; ensure sparse checkout on */
+	record_mode = (*cone_mode != -1) || !core_apply_sparse_checkout;
+
+	mode = update_cone_mode(cone_mode);
+	if (record_mode && set_config(mode))
+		return 1;
+
+	/* Set sparse-index/non-sparse-index mode if specified */
+	if (*sparse_index >= 0) {
+		if (set_sparse_index_config(the_repository, *sparse_index) < 0)
+			die(_("failed to modify sparse-index config"));
+
+		/* force an index rewrite */
+		repo_read_index(the_repository);
+		the_repository->index->updated_workdir = 1;
+
+		if (!*sparse_index)
+			ensure_full_index(the_repository->index);
+	}
+
+	return 0;
+}
+
+static char const * const builtin_sparse_checkout_init_usage[] = {
+	"git sparse-checkout init [--cone] [--[no-]sparse-index]",
+	NULL
+};
+
+static struct sparse_checkout_init_opts {
+	int cone_mode;
+	int sparse_index;
+} init_opts;
+
+static int sparse_checkout_init(int argc, const char **argv, const char *prefix)
+{
+	struct pattern_list pl;
+	char *sparse_filename;
+	int res;
+	struct object_id oid;
+	struct strbuf pattern = STRBUF_INIT;
+
+	static struct option builtin_sparse_checkout_init_options[] = {
+		OPT_BOOL(0, "cone", &init_opts.cone_mode,
+			 N_("initialize the sparse-checkout in cone mode")),
+		OPT_BOOL(0, "sparse-index", &init_opts.sparse_index,
+			 N_("toggle the use of a sparse index")),
+		OPT_END(),
+	};
+
+	setup_work_tree();
+	repo_read_index(the_repository);
+
+	init_opts.cone_mode = -1;
+	init_opts.sparse_index = -1;
+
+	argc = parse_options(argc, argv, prefix,
+			     builtin_sparse_checkout_init_options,
+			     builtin_sparse_checkout_init_usage, 0);
+
+	if (update_modes(&init_opts.cone_mode, &init_opts.sparse_index))
+		return 1;
+
+	memset(&pl, 0, sizeof(pl));
+
+	sparse_filename = get_sparse_checkout_filename();
+	res = add_patterns_from_file_to_list(sparse_filename, "", 0, &pl, NULL, 0);
+
+	/* If we already have a sparse-checkout file, use it. */
+	if (res >= 0) {
+		free(sparse_filename);
+		return update_working_directory(NULL);
+	}
+
+	if (repo_get_oid(the_repository, "HEAD", &oid)) {
+		FILE *fp;
+
+		/* assume we are in a fresh repo, but update the sparse-checkout file */
+		if (safe_create_leading_directories(sparse_filename))
+			die(_("unable to create leading directories of %s"),
+			    sparse_filename);
+		fp = xfopen(sparse_filename, "w");
+		if (!fp)
+			die(_("failed to open '%s'"), sparse_filename);
+
+		free(sparse_filename);
+		fprintf(fp, "/*\n!/*/\n");
+		fclose(fp);
+		return 0;
+	}
+
+	strbuf_addstr(&pattern, "/*");
+	add_pattern(strbuf_detach(&pattern, NULL), empty_base, 0, &pl, 0);
+	strbuf_addstr(&pattern, "!/*/");
+	add_pattern(strbuf_detach(&pattern, NULL), empty_base, 0, &pl, 0);
+	pl.use_cone_patterns = init_opts.cone_mode;
+
+	return write_patterns_and_update(&pl);
+}
+
+static void insert_recursive_pattern(struct pattern_list *pl, struct strbuf *path)
+{
+	struct pattern_entry *e = xmalloc(sizeof(*e));
+	e->patternlen = path->len;
+	e->pattern = strbuf_detach(path, NULL);
+	hashmap_entry_init(&e->ent, fspathhash(e->pattern));
+
+	hashmap_add(&pl->recursive_hashmap, &e->ent);
+
+	while (e->patternlen) {
+		char *slash = strrchr(e->pattern, '/');
+		char *oldpattern = e->pattern;
+		size_t newlen;
+
+		if (!slash || slash == e->pattern)
+			break;
+
+		newlen = slash - e->pattern;
+		e = xmalloc(sizeof(struct pattern_entry));
+		e->patternlen = newlen;
+		e->pattern = xstrndup(oldpattern, newlen);
+		hashmap_entry_init(&e->ent, fspathhash(e->pattern));
+
+		if (!hashmap_get_entry(&pl->parent_hashmap, e, ent, NULL))
+			hashmap_add(&pl->parent_hashmap, &e->ent);
+	}
+}
+
+static void strbuf_to_cone_pattern(struct strbuf *line, struct pattern_list *pl)
+{
+	strbuf_trim(line);
+
+	strbuf_trim_trailing_dir_sep(line);
+
+	if (strbuf_normalize_path(line))
+		die(_("could not normalize path %s"), line->buf);
+
+	if (!line->len)
+		return;
+
+	if (line->buf[0] != '/')
+		strbuf_insertstr(line, 0, "/");
+
+	insert_recursive_pattern(pl, line);
+}
+
+static void add_patterns_from_input(struct pattern_list *pl,
+				    int argc, const char **argv,
+				    FILE *file)
+{
+	int i;
+	if (core_sparse_checkout_cone) {
+		struct strbuf line = STRBUF_INIT;
+
+		hashmap_init(&pl->recursive_hashmap, pl_hashmap_cmp, NULL, 0);
+		hashmap_init(&pl->parent_hashmap, pl_hashmap_cmp, NULL, 0);
+		pl->use_cone_patterns = 1;
+
+		if (file) {
+			struct strbuf unquoted = STRBUF_INIT;
+			while (!strbuf_getline(&line, file)) {
+				if (line.buf[0] == '"') {
+					strbuf_reset(&unquoted);
+					if (unquote_c_style(&unquoted, line.buf, NULL))
+						die(_("unable to unquote C-style string '%s'"),
+						line.buf);
+
+					strbuf_swap(&unquoted, &line);
+				}
+
+				strbuf_to_cone_pattern(&line, pl);
+			}
+
+			strbuf_release(&unquoted);
+		} else {
+			for (i = 0; i < argc; i++) {
+				strbuf_setlen(&line, 0);
+				strbuf_addstr(&line, argv[i]);
+				strbuf_to_cone_pattern(&line, pl);
+			}
+		}
+	} else {
+		if (file) {
+			struct strbuf line = STRBUF_INIT;
+
+			while (!strbuf_getline(&line, file)) {
+				size_t len;
+				char *buf = strbuf_detach(&line, &len);
+				add_pattern(buf, empty_base, 0, pl, 0);
+			}
+		} else {
+			for (i = 0; i < argc; i++)
+				add_pattern(argv[i], empty_base, 0, pl, 0);
+		}
+	}
+}
+
+enum modify_type {
+	REPLACE,
+	ADD,
+};
+
+static void add_patterns_cone_mode(int argc, const char **argv,
+				   struct pattern_list *pl,
+				   int use_stdin)
+{
+	struct strbuf buffer = STRBUF_INIT;
+	struct pattern_entry *pe;
+	struct hashmap_iter iter;
+	struct pattern_list existing;
+	char *sparse_filename = get_sparse_checkout_filename();
+
+	add_patterns_from_input(pl, argc, argv,
+				use_stdin ? stdin : NULL);
+
+	memset(&existing, 0, sizeof(existing));
+	existing.use_cone_patterns = core_sparse_checkout_cone;
+
+	if (add_patterns_from_file_to_list(sparse_filename, "", 0,
+					   &existing, NULL, 0))
+		die(_("unable to load existing sparse-checkout patterns"));
+	free(sparse_filename);
+
+	if (!existing.use_cone_patterns)
+		die(_("existing sparse-checkout patterns do not use cone mode"));
+
+	hashmap_for_each_entry(&existing.recursive_hashmap, &iter, pe, ent) {
+		if (!hashmap_contains_parent(&pl->recursive_hashmap,
+					pe->pattern, &buffer) ||
+		    !hashmap_contains_parent(&pl->parent_hashmap,
+					pe->pattern, &buffer)) {
+			strbuf_reset(&buffer);
+			strbuf_addstr(&buffer, pe->pattern);
+			insert_recursive_pattern(pl, &buffer);
+		}
+	}
+
+	clear_pattern_list(&existing);
+	strbuf_release(&buffer);
+}
+
+static void add_patterns_literal(int argc, const char **argv,
+				 struct pattern_list *pl,
+				 int use_stdin)
+{
+	char *sparse_filename = get_sparse_checkout_filename();
+	if (add_patterns_from_file_to_list(sparse_filename, "", 0,
+					   pl, NULL, 0))
+		die(_("unable to load existing sparse-checkout patterns"));
+	free(sparse_filename);
+	add_patterns_from_input(pl, argc, argv, use_stdin ? stdin : NULL);
+}
+
+static int modify_pattern_list(int argc, const char **argv, int use_stdin,
+			       enum modify_type m)
+{
+	int result;
+	int changed_config = 0;
+	struct pattern_list *pl = xcalloc(1, sizeof(*pl));
+
+	switch (m) {
+	case ADD:
+		if (core_sparse_checkout_cone)
+			add_patterns_cone_mode(argc, argv, pl, use_stdin);
+		else
+			add_patterns_literal(argc, argv, pl, use_stdin);
+		break;
+
+	case REPLACE:
+		add_patterns_from_input(pl, argc, argv,
+					use_stdin ? stdin : NULL);
+		break;
+	}
+
+	if (!core_apply_sparse_checkout) {
+		set_config(MODE_ALL_PATTERNS);
+		core_apply_sparse_checkout = 1;
+		changed_config = 1;
+	}
+
+	result = write_patterns_and_update(pl);
+
+	if (result && changed_config)
+		set_config(MODE_NO_PATTERNS);
+
+	clear_pattern_list(pl);
+	free(pl);
+	return result;
+}
+
+static void sanitize_paths(int argc, const char **argv,
+			   const char *prefix, int skip_checks)
+{
+	int i;
+
+	if (!argc)
+		return;
+
+	if (prefix && *prefix && core_sparse_checkout_cone) {
+		/*
+		 * The args are not pathspecs, so unfortunately we
+		 * cannot imitate how cmd_add() uses parse_pathspec().
+		 */
+		int prefix_len = strlen(prefix);
+
+		for (i = 0; i < argc; i++)
+			argv[i] = prefix_path(prefix, prefix_len, argv[i]);
+	}
+
+	if (skip_checks)
+		return;
+
+	if (prefix && *prefix && !core_sparse_checkout_cone)
+		die(_("please run from the toplevel directory in non-cone mode"));
+
+	if (core_sparse_checkout_cone) {
+		for (i = 0; i < argc; i++) {
+			if (argv[i][0] == '/')
+				die(_("specify directories rather than patterns (no leading slash)"));
+			if (argv[i][0] == '!')
+				die(_("specify directories rather than patterns.  If your directory starts with a '!', pass --skip-checks"));
+			if (strpbrk(argv[i], "*?[]"))
+				die(_("specify directories rather than patterns.  If your directory really has any of '*?[]\\' in it, pass --skip-checks"));
+		}
+	}
+
+	for (i = 0; i < argc; i++) {
+		struct cache_entry *ce;
+		struct index_state *index = the_repository->index;
+		int pos = index_name_pos(index, argv[i], strlen(argv[i]));
+
+		if (pos < 0)
+			continue;
+		ce = index->cache[pos];
+		if (S_ISSPARSEDIR(ce->ce_mode))
+			continue;
+
+		if (core_sparse_checkout_cone)
+			die(_("'%s' is not a directory; to treat it as a directory anyway, rerun with --skip-checks"), argv[i]);
+		else
+			warning(_("pass a leading slash before paths such as '%s' if you want a single file (see NON-CONE PROBLEMS in the git-sparse-checkout manual)."), argv[i]);
+	}
+}
+
+static char const * const builtin_sparse_checkout_add_usage[] = {
+	N_("git sparse-checkout add [--skip-checks] (--stdin | <patterns>)"),
+	NULL
+};
+
+static struct sparse_checkout_add_opts {
+	int skip_checks;
+	int use_stdin;
+} add_opts;
+
+static int sparse_checkout_add(int argc, const char **argv, const char *prefix)
+{
+	static struct option builtin_sparse_checkout_add_options[] = {
+		OPT_BOOL_F(0, "skip-checks", &add_opts.skip_checks,
+			   N_("skip some sanity checks on the given paths that might give false positives"),
+			   PARSE_OPT_NONEG),
+		OPT_BOOL(0, "stdin", &add_opts.use_stdin,
+			 N_("read patterns from standard in")),
+		OPT_END(),
+	};
+
+	setup_work_tree();
+	if (!core_apply_sparse_checkout)
+		die(_("no sparse-checkout to add to"));
+
+	repo_read_index(the_repository);
+
+	argc = parse_options(argc, argv, prefix,
+			     builtin_sparse_checkout_add_options,
+			     builtin_sparse_checkout_add_usage,
+			     PARSE_OPT_KEEP_UNKNOWN_OPT);
+
+	sanitize_paths(argc, argv, prefix, add_opts.skip_checks);
+
+	return modify_pattern_list(argc, argv, add_opts.use_stdin, ADD);
+}
+
+static char const * const builtin_sparse_checkout_set_usage[] = {
+	N_("git sparse-checkout set [--[no-]cone] [--[no-]sparse-index] [--skip-checks] (--stdin | <patterns>)"),
+	NULL
+};
+
+static struct sparse_checkout_set_opts {
+	int cone_mode;
+	int sparse_index;
+	int skip_checks;
+	int use_stdin;
+} set_opts;
+
+static int sparse_checkout_set(int argc, const char **argv, const char *prefix)
+{
+	int default_patterns_nr = 2;
+	const char *default_patterns[] = {"/*", "!/*/", NULL};
+
+	static struct option builtin_sparse_checkout_set_options[] = {
+		OPT_BOOL(0, "cone", &set_opts.cone_mode,
+			 N_("initialize the sparse-checkout in cone mode")),
+		OPT_BOOL(0, "sparse-index", &set_opts.sparse_index,
+			 N_("toggle the use of a sparse index")),
+		OPT_BOOL_F(0, "skip-checks", &set_opts.skip_checks,
+			   N_("skip some sanity checks on the given paths that might give false positives"),
+			   PARSE_OPT_NONEG),
+		OPT_BOOL_F(0, "stdin", &set_opts.use_stdin,
+			   N_("read patterns from standard in"),
+			   PARSE_OPT_NONEG),
+		OPT_END(),
+	};
+
+	setup_work_tree();
+	repo_read_index(the_repository);
+
+	set_opts.cone_mode = -1;
+	set_opts.sparse_index = -1;
+
+	argc = parse_options(argc, argv, prefix,
+			     builtin_sparse_checkout_set_options,
+			     builtin_sparse_checkout_set_usage,
+			     PARSE_OPT_KEEP_UNKNOWN_OPT);
+
+	if (update_modes(&set_opts.cone_mode, &set_opts.sparse_index))
+		return 1;
+
+	/*
+	 * Cone mode automatically specifies the toplevel directory.  For
+	 * non-cone mode, if nothing is specified, manually select just the
+	 * top-level directory (much as 'init' would do).
+	 */
+	if (!core_sparse_checkout_cone && argc == 0) {
+		argv = default_patterns;
+		argc = default_patterns_nr;
+	} else {
+		sanitize_paths(argc, argv, prefix, set_opts.skip_checks);
+	}
+
+	return modify_pattern_list(argc, argv, set_opts.use_stdin, REPLACE);
+}
+
+static char const * const builtin_sparse_checkout_reapply_usage[] = {
+	"git sparse-checkout reapply [--[no-]cone] [--[no-]sparse-index]",
+	NULL
+};
+
+static struct sparse_checkout_reapply_opts {
+	int cone_mode;
+	int sparse_index;
+} reapply_opts;
+
+static int sparse_checkout_reapply(int argc, const char **argv,
+				   const char *prefix)
+{
+	static struct option builtin_sparse_checkout_reapply_options[] = {
+		OPT_BOOL(0, "cone", &reapply_opts.cone_mode,
+			 N_("initialize the sparse-checkout in cone mode")),
+		OPT_BOOL(0, "sparse-index", &reapply_opts.sparse_index,
+			 N_("toggle the use of a sparse index")),
+		OPT_END(),
+	};
+
+	setup_work_tree();
+	if (!core_apply_sparse_checkout)
+		die(_("must be in a sparse-checkout to reapply sparsity patterns"));
+
+	reapply_opts.cone_mode = -1;
+	reapply_opts.sparse_index = -1;
+
+	argc = parse_options(argc, argv, prefix,
+			     builtin_sparse_checkout_reapply_options,
+			     builtin_sparse_checkout_reapply_usage, 0);
+
+	repo_read_index(the_repository);
+
+	if (update_modes(&reapply_opts.cone_mode, &reapply_opts.sparse_index))
+		return 1;
+
+	return update_working_directory(NULL);
+}
+
+static char const * const builtin_sparse_checkout_disable_usage[] = {
+	"git sparse-checkout disable",
+	NULL
+};
+
+static int sparse_checkout_disable(int argc, const char **argv,
+				   const char *prefix)
+{
+	static struct option builtin_sparse_checkout_disable_options[] = {
+		OPT_END(),
+	};
+	struct pattern_list pl;
+	struct strbuf match_all = STRBUF_INIT;
+
+	/*
+	 * We do not exit early if !core_apply_sparse_checkout; due to the
+	 * ability for users to manually muck things up between
+	 *   direct editing of .git/info/sparse-checkout
+	 *   running read-tree -m u HEAD or update-index --skip-worktree
+	 *   direct toggling of config options
+	 * users might end up with an index with SKIP_WORKTREE bit set on
+	 * some files and not know how to undo it.  So, here we just
+	 * forcibly return to a dense checkout regardless of initial state.
+	 */
+
+	setup_work_tree();
+	argc = parse_options(argc, argv, prefix,
+			     builtin_sparse_checkout_disable_options,
+			     builtin_sparse_checkout_disable_usage, 0);
+
+	repo_read_index(the_repository);
+
+	memset(&pl, 0, sizeof(pl));
+	hashmap_init(&pl.recursive_hashmap, pl_hashmap_cmp, NULL, 0);
+	hashmap_init(&pl.parent_hashmap, pl_hashmap_cmp, NULL, 0);
+	pl.use_cone_patterns = 0;
+	core_apply_sparse_checkout = 1;
+
+	strbuf_addstr(&match_all, "/*");
+	add_pattern(strbuf_detach(&match_all, NULL), empty_base, 0, &pl, 0);
+
+	prepare_repo_settings(the_repository);
+	the_repository->settings.sparse_index = 0;
+
+	if (update_working_directory(&pl))
+		die(_("error while refreshing working directory"));
+
+	clear_pattern_list(&pl);
+	return set_config(MODE_NO_PATTERNS);
+}
+
+static char const * const builtin_sparse_checkout_check_rules_usage[] = {
+	N_("git sparse-checkout check-rules [-z] [--skip-checks]"
+	   "[--[no-]cone] [--rules-file <file>]"),
+	NULL
+};
+
+static struct sparse_checkout_check_rules_opts {
+	int cone_mode;
+	int null_termination;
+	char *rules_file;
+} check_rules_opts;
+
+static int check_rules(struct pattern_list *pl, int null_terminated) {
+	struct strbuf line = STRBUF_INIT;
+	struct strbuf unquoted = STRBUF_INIT;
+	char *path;
+	int line_terminator = null_terminated ? 0 : '\n';
+	strbuf_getline_fn getline_fn = null_terminated ? strbuf_getline_nul
+		: strbuf_getline;
+	the_repository->index->sparse_checkout_patterns = pl;
+	while (!getline_fn(&line, stdin)) {
+		path = line.buf;
+		if (!null_terminated && line.buf[0] == '"') {
+			strbuf_reset(&unquoted);
+			if (unquote_c_style(&unquoted, line.buf, NULL))
+				die(_("unable to unquote C-style string '%s'"),
+					line.buf);
+
+			path = unquoted.buf;
+		}
+
+		if (path_in_sparse_checkout(path, the_repository->index))
+			write_name_quoted(path, stdout, line_terminator);
+	}
+	strbuf_release(&line);
+	strbuf_release(&unquoted);
+
+	return 0;
+}
+
+static int sparse_checkout_check_rules(int argc, const char **argv, const char *prefix)
+{
+	static struct option builtin_sparse_checkout_check_rules_options[] = {
+		OPT_BOOL('z', NULL, &check_rules_opts.null_termination,
+			 N_("terminate input and output files by a NUL character")),
+		OPT_BOOL(0, "cone", &check_rules_opts.cone_mode,
+			 N_("when used with --rules-file interpret patterns as cone mode patterns")),
+		OPT_FILENAME(0, "rules-file", &check_rules_opts.rules_file,
+			 N_("use patterns in <file> instead of the current ones.")),
+		OPT_END(),
+	};
+
+	FILE *fp;
+	int ret;
+	struct pattern_list pl = {0};
+	char *sparse_filename;
+	check_rules_opts.cone_mode = -1;
+
+	argc = parse_options(argc, argv, prefix,
+			     builtin_sparse_checkout_check_rules_options,
+			     builtin_sparse_checkout_check_rules_usage,
+			     PARSE_OPT_KEEP_UNKNOWN_OPT);
+
+	if (check_rules_opts.rules_file && check_rules_opts.cone_mode < 0)
+		check_rules_opts.cone_mode = 1;
+
+	update_cone_mode(&check_rules_opts.cone_mode);
+	pl.use_cone_patterns = core_sparse_checkout_cone;
+	if (check_rules_opts.rules_file) {
+		fp = xfopen(check_rules_opts.rules_file, "r");
+		add_patterns_from_input(&pl, argc, argv, fp);
+		fclose(fp);
+	} else {
+		sparse_filename = get_sparse_checkout_filename();
+		if (add_patterns_from_file_to_list(sparse_filename, "", 0, &pl,
+						   NULL, 0))
+			die(_("unable to load existing sparse-checkout patterns"));
+		free(sparse_filename);
+	}
+
+	ret = check_rules(&pl, check_rules_opts.null_termination);
+	clear_pattern_list(&pl);
+	return ret;
+}
+
+int cmd_sparse_checkout(int argc, const char **argv, const char *prefix)
+{
+	parse_opt_subcommand_fn *fn = NULL;
+	struct option builtin_sparse_checkout_options[] = {
+		OPT_SUBCOMMAND("list", &fn, sparse_checkout_list),
+		OPT_SUBCOMMAND("init", &fn, sparse_checkout_init),
+		OPT_SUBCOMMAND("set", &fn, sparse_checkout_set),
+		OPT_SUBCOMMAND("add", &fn, sparse_checkout_add),
+		OPT_SUBCOMMAND("reapply", &fn, sparse_checkout_reapply),
+		OPT_SUBCOMMAND("disable", &fn, sparse_checkout_disable),
+		OPT_SUBCOMMAND("check-rules", &fn, sparse_checkout_check_rules),
+		OPT_END(),
+	};
+
+	argc = parse_options(argc, argv, prefix,
+			     builtin_sparse_checkout_options,
+			     builtin_sparse_checkout_usage, 0);
+
+	git_config(git_default_config, NULL);
+
+	prepare_repo_settings(the_repository);
+	the_repository->settings.command_requires_full_index = 0;
+
+	return fn(argc, argv, prefix);
+}