Squashed 'third_party/git/' content from commit cb71568594

git-subtree-dir: third_party/git
git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7

1 files changed, 594 insertions, 0 deletions

diff --git a/worktree.c b/worktree.c
new file mode 100644
index 0000000000..5b4793caa3
--- /dev/null
+++ b/worktree.c
@@ -0,0 +1,594 @@
+#include "cache.h"
+#include "repository.h"
+#include "refs.h"
+#include "strbuf.h"
+#include "worktree.h"
+#include "dir.h"
+#include "wt-status.h"
+
+void free_worktrees(struct worktree **worktrees)
+{
+	int i = 0;
+
+	for (i = 0; worktrees[i]; i++) {
+		free(worktrees[i]->path);
+		free(worktrees[i]->id);
+		free(worktrees[i]->head_ref);
+		free(worktrees[i]->lock_reason);
+		free(worktrees[i]);
+	}
+	free (worktrees);
+}
+
+/**
+ * Update head_sha1, head_ref and is_detached of the given worktree
+ */
+static void add_head_info(struct worktree *wt)
+{
+	int flags;
+	const char *target;
+
+	target = refs_resolve_ref_unsafe(get_worktree_ref_store(wt),
+					 "HEAD",
+					 0,
+					 &wt->head_oid, &flags);
+	if (!target)
+		return;
+
+	if (flags & REF_ISSYMREF)
+		wt->head_ref = xstrdup(target);
+	else
+		wt->is_detached = 1;
+}
+
+/**
+ * get the main worktree
+ */
+static struct worktree *get_main_worktree(void)
+{
+	struct worktree *worktree = NULL;
+	struct strbuf path = STRBUF_INIT;
+	struct strbuf worktree_path = STRBUF_INIT;
+
+	strbuf_add_absolute_path(&worktree_path, get_git_common_dir());
+	if (!strbuf_strip_suffix(&worktree_path, "/.git"))
+		strbuf_strip_suffix(&worktree_path, "/.");
+
+	strbuf_addf(&path, "%s/HEAD", get_git_common_dir());
+
+	worktree = xcalloc(1, sizeof(*worktree));
+	worktree->path = strbuf_detach(&worktree_path, NULL);
+	/*
+	 * NEEDSWORK: If this function is called from a secondary worktree and
+	 * config.worktree is present, is_bare_repository_cfg will reflect the
+	 * contents of config.worktree, not the contents of the main worktree.
+	 * This means that worktree->is_bare may be set to 0 even if the main
+	 * worktree is configured to be bare.
+	 */
+	worktree->is_bare = (is_bare_repository_cfg == 1) ||
+		is_bare_repository();
+	add_head_info(worktree);
+
+	strbuf_release(&path);
+	strbuf_release(&worktree_path);
+	return worktree;
+}
+
+static struct worktree *get_linked_worktree(const char *id)
+{
+	struct worktree *worktree = NULL;
+	struct strbuf path = STRBUF_INIT;
+	struct strbuf worktree_path = STRBUF_INIT;
+
+	if (!id)
+		die("Missing linked worktree name");
+
+	strbuf_git_common_path(&path, the_repository, "worktrees/%s/gitdir", id);
+	if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
+		/* invalid gitdir file */
+		goto done;
+
+	strbuf_rtrim(&worktree_path);
+	if (!strbuf_strip_suffix(&worktree_path, "/.git")) {
+		strbuf_reset(&worktree_path);
+		strbuf_add_absolute_path(&worktree_path, ".");
+		strbuf_strip_suffix(&worktree_path, "/.");
+	}
+
+	strbuf_reset(&path);
+	strbuf_addf(&path, "%s/worktrees/%s/HEAD", get_git_common_dir(), id);
+
+	worktree = xcalloc(1, sizeof(*worktree));
+	worktree->path = strbuf_detach(&worktree_path, NULL);
+	worktree->id = xstrdup(id);
+	add_head_info(worktree);
+
+done:
+	strbuf_release(&path);
+	strbuf_release(&worktree_path);
+	return worktree;
+}
+
+static void mark_current_worktree(struct worktree **worktrees)
+{
+	char *git_dir = absolute_pathdup(get_git_dir());
+	int i;
+
+	for (i = 0; worktrees[i]; i++) {
+		struct worktree *wt = worktrees[i];
+		const char *wt_git_dir = get_worktree_git_dir(wt);
+
+		if (!fspathcmp(git_dir, absolute_path(wt_git_dir))) {
+			wt->is_current = 1;
+			break;
+		}
+	}
+	free(git_dir);
+}
+
+static int compare_worktree(const void *a_, const void *b_)
+{
+	const struct worktree *const *a = a_;
+	const struct worktree *const *b = b_;
+	return fspathcmp((*a)->path, (*b)->path);
+}
+
+struct worktree **get_worktrees(unsigned flags)
+{
+	struct worktree **list = NULL;
+	struct strbuf path = STRBUF_INIT;
+	DIR *dir;
+	struct dirent *d;
+	int counter = 0, alloc = 2;
+
+	ALLOC_ARRAY(list, alloc);
+
+	list[counter++] = get_main_worktree();
+
+	strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
+	dir = opendir(path.buf);
+	strbuf_release(&path);
+	if (dir) {
+		while ((d = readdir(dir)) != NULL) {
+			struct worktree *linked = NULL;
+			if (is_dot_or_dotdot(d->d_name))
+				continue;
+
+			if ((linked = get_linked_worktree(d->d_name))) {
+				ALLOC_GROW(list, counter + 1, alloc);
+				list[counter++] = linked;
+			}
+		}
+		closedir(dir);
+	}
+	ALLOC_GROW(list, counter + 1, alloc);
+	list[counter] = NULL;
+
+	if (flags & GWT_SORT_LINKED)
+		/*
+		 * don't sort the first item (main worktree), which will
+		 * always be the first
+		 */
+		QSORT(list + 1, counter - 1, compare_worktree);
+
+	mark_current_worktree(list);
+	return list;
+}
+
+const char *get_worktree_git_dir(const struct worktree *wt)
+{
+	if (!wt)
+		return get_git_dir();
+	else if (!wt->id)
+		return get_git_common_dir();
+	else
+		return git_common_path("worktrees/%s", wt->id);
+}
+
+static struct worktree *find_worktree_by_suffix(struct worktree **list,
+						const char *suffix)
+{
+	struct worktree *found = NULL;
+	int nr_found = 0, suffixlen;
+
+	suffixlen = strlen(suffix);
+	if (!suffixlen)
+		return NULL;
+
+	for (; *list && nr_found < 2; list++) {
+		const char	*path	 = (*list)->path;
+		int		 pathlen = strlen(path);
+		int		 start	 = pathlen - suffixlen;
+
+		/* suffix must start at directory boundary */
+		if ((!start || (start > 0 && is_dir_sep(path[start - 1]))) &&
+		    !fspathcmp(suffix, path + start)) {
+			found = *list;
+			nr_found++;
+		}
+	}
+	return nr_found == 1 ? found : NULL;
+}
+
+struct worktree *find_worktree(struct worktree **list,
+			       const char *prefix,
+			       const char *arg)
+{
+	struct worktree *wt;
+	char *path;
+	char *to_free = NULL;
+
+	if ((wt = find_worktree_by_suffix(list, arg)))
+		return wt;
+
+	if (prefix)
+		arg = to_free = prefix_filename(prefix, arg);
+	path = real_pathdup(arg, 0);
+	if (!path) {
+		free(to_free);
+		return NULL;
+	}
+	for (; *list; list++) {
+		const char *wt_path = real_path_if_valid((*list)->path);
+
+		if (wt_path && !fspathcmp(path, wt_path))
+			break;
+	}
+	free(path);
+	free(to_free);
+	return *list;
+}
+
+int is_main_worktree(const struct worktree *wt)
+{
+	return !wt->id;
+}
+
+const char *worktree_lock_reason(struct worktree *wt)
+{
+	assert(!is_main_worktree(wt));
+
+	if (!wt->lock_reason_valid) {
+		struct strbuf path = STRBUF_INIT;
+
+		strbuf_addstr(&path, worktree_git_path(wt, "locked"));
+		if (file_exists(path.buf)) {
+			struct strbuf lock_reason = STRBUF_INIT;
+			if (strbuf_read_file(&lock_reason, path.buf, 0) < 0)
+				die_errno(_("failed to read '%s'"), path.buf);
+			strbuf_trim(&lock_reason);
+			wt->lock_reason = strbuf_detach(&lock_reason, NULL);
+		} else
+			wt->lock_reason = NULL;
+		wt->lock_reason_valid = 1;
+		strbuf_release(&path);
+	}
+
+	return wt->lock_reason;
+}
+
+/* convenient wrapper to deal with NULL strbuf */
+static void strbuf_addf_gently(struct strbuf *buf, const char *fmt, ...)
+{
+	va_list params;
+
+	if (!buf)
+		return;
+
+	va_start(params, fmt);
+	strbuf_vaddf(buf, fmt, params);
+	va_end(params);
+}
+
+int validate_worktree(const struct worktree *wt, struct strbuf *errmsg,
+		      unsigned flags)
+{
+	struct strbuf wt_path = STRBUF_INIT;
+	char *path = NULL;
+	int err, ret = -1;
+
+	strbuf_addf(&wt_path, "%s/.git", wt->path);
+
+	if (is_main_worktree(wt)) {
+		if (is_directory(wt_path.buf)) {
+			ret = 0;
+			goto done;
+		}
+		/*
+		 * Main worktree using .git file to point to the
+		 * repository would make it impossible to know where
+		 * the actual worktree is if this function is executed
+		 * from another worktree. No .git file support for now.
+		 */
+		strbuf_addf_gently(errmsg,
+				   _("'%s' at main working tree is not the repository directory"),
+				   wt_path.buf);
+		goto done;
+	}
+
+	/*
+	 * Make sure "gitdir" file points to a real .git file and that
+	 * file points back here.
+	 */
+	if (!is_absolute_path(wt->path)) {
+		strbuf_addf_gently(errmsg,
+				   _("'%s' file does not contain absolute path to the working tree location"),
+				   git_common_path("worktrees/%s/gitdir", wt->id));
+		goto done;
+	}
+
+	if (flags & WT_VALIDATE_WORKTREE_MISSING_OK &&
+	    !file_exists(wt->path)) {
+		ret = 0;
+		goto done;
+	}
+
+	if (!file_exists(wt_path.buf)) {
+		strbuf_addf_gently(errmsg, _("'%s' does not exist"), wt_path.buf);
+		goto done;
+	}
+
+	path = xstrdup_or_null(read_gitfile_gently(wt_path.buf, &err));
+	if (!path) {
+		strbuf_addf_gently(errmsg, _("'%s' is not a .git file, error code %d"),
+				   wt_path.buf, err);
+		goto done;
+	}
+
+	ret = fspathcmp(path, real_path(git_common_path("worktrees/%s", wt->id)));
+
+	if (ret)
+		strbuf_addf_gently(errmsg, _("'%s' does not point back to '%s'"),
+				   wt->path, git_common_path("worktrees/%s", wt->id));
+done:
+	free(path);
+	strbuf_release(&wt_path);
+	return ret;
+}
+
+void update_worktree_location(struct worktree *wt, const char *path_)
+{
+	struct strbuf path = STRBUF_INIT;
+
+	if (is_main_worktree(wt))
+		BUG("can't relocate main worktree");
+
+	strbuf_realpath(&path, path_, 1);
+	if (fspathcmp(wt->path, path.buf)) {
+		write_file(git_common_path("worktrees/%s/gitdir", wt->id),
+			   "%s/.git", path.buf);
+		free(wt->path);
+		wt->path = strbuf_detach(&path, NULL);
+	}
+	strbuf_release(&path);
+}
+
+int is_worktree_being_rebased(const struct worktree *wt,
+			      const char *target)
+{
+	struct wt_status_state state;
+	int found_rebase;
+
+	memset(&state, 0, sizeof(state));
+	found_rebase = wt_status_check_rebase(wt, &state) &&
+		((state.rebase_in_progress ||
+		  state.rebase_interactive_in_progress) &&
+		 state.branch &&
+		 starts_with(target, "refs/heads/") &&
+		 !strcmp(state.branch, target + strlen("refs/heads/")));
+	free(state.branch);
+	free(state.onto);
+	return found_rebase;
+}
+
+int is_worktree_being_bisected(const struct worktree *wt,
+			       const char *target)
+{
+	struct wt_status_state state;
+	int found_rebase;
+
+	memset(&state, 0, sizeof(state));
+	found_rebase = wt_status_check_bisect(wt, &state) &&
+		state.branch &&
+		starts_with(target, "refs/heads/") &&
+		!strcmp(state.branch, target + strlen("refs/heads/"));
+	free(state.branch);
+	return found_rebase;
+}
+
+/*
+ * note: this function should be able to detect shared symref even if
+ * HEAD is temporarily detached (e.g. in the middle of rebase or
+ * bisect). New commands that do similar things should update this
+ * function as well.
+ */
+const struct worktree *find_shared_symref(const char *symref,
+					  const char *target)
+{
+	const struct worktree *existing = NULL;
+	static struct worktree **worktrees;
+	int i = 0;
+
+	if (worktrees)
+		free_worktrees(worktrees);
+	worktrees = get_worktrees(0);
+
+	for (i = 0; worktrees[i]; i++) {
+		struct worktree *wt = worktrees[i];
+		const char *symref_target;
+		struct ref_store *refs;
+		int flags;
+
+		if (wt->is_bare)
+			continue;
+
+		if (wt->is_detached && !strcmp(symref, "HEAD")) {
+			if (is_worktree_being_rebased(wt, target)) {
+				existing = wt;
+				break;
+			}
+			if (is_worktree_being_bisected(wt, target)) {
+				existing = wt;
+				break;
+			}
+		}
+
+		refs = get_worktree_ref_store(wt);
+		symref_target = refs_resolve_ref_unsafe(refs, symref, 0,
+							NULL, &flags);
+		if ((flags & REF_ISSYMREF) &&
+		    symref_target && !strcmp(symref_target, target)) {
+			existing = wt;
+			break;
+		}
+	}
+
+	return existing;
+}
+
+int submodule_uses_worktrees(const char *path)
+{
+	char *submodule_gitdir;
+	struct strbuf sb = STRBUF_INIT;
+	DIR *dir;
+	struct dirent *d;
+	int ret = 0;
+	struct repository_format format = REPOSITORY_FORMAT_INIT;
+
+	submodule_gitdir = git_pathdup_submodule(path, "%s", "");
+	if (!submodule_gitdir)
+		return 0;
+
+	/* The env would be set for the superproject. */
+	get_common_dir_noenv(&sb, submodule_gitdir);
+	free(submodule_gitdir);
+
+	/*
+	 * The check below is only known to be good for repository format
+	 * version 0 at the time of writing this code.
+	 */
+	strbuf_addstr(&sb, "/config");
+	read_repository_format(&format, sb.buf);
+	if (format.version != 0) {
+		strbuf_release(&sb);
+		clear_repository_format(&format);
+		return 1;
+	}
+	clear_repository_format(&format);
+
+	/* Replace config by worktrees. */
+	strbuf_setlen(&sb, sb.len - strlen("config"));
+	strbuf_addstr(&sb, "worktrees");
+
+	/* See if there is any file inside the worktrees directory. */
+	dir = opendir(sb.buf);
+	strbuf_release(&sb);
+
+	if (!dir)
+		return 0;
+
+	while ((d = readdir(dir)) != NULL) {
+		if (is_dot_or_dotdot(d->d_name))
+			continue;
+
+		ret = 1;
+		break;
+	}
+	closedir(dir);
+	return ret;
+}
+
+int parse_worktree_ref(const char *worktree_ref, const char **name,
+		       int *name_length, const char **ref)
+{
+	if (skip_prefix(worktree_ref, "main-worktree/", &worktree_ref)) {
+		if (!*worktree_ref)
+			return -1;
+		if (name)
+			*name = NULL;
+		if (name_length)
+			*name_length = 0;
+		if (ref)
+			*ref = worktree_ref;
+		return 0;
+	}
+	if (skip_prefix(worktree_ref, "worktrees/", &worktree_ref)) {
+		const char *slash = strchr(worktree_ref, '/');
+
+		if (!slash || slash == worktree_ref || !slash[1])
+			return -1;
+		if (name)
+			*name = worktree_ref;
+		if (name_length)
+			*name_length = slash - worktree_ref;
+		if (ref)
+			*ref = slash + 1;
+		return 0;
+	}
+	return -1;
+}
+
+void strbuf_worktree_ref(const struct worktree *wt,
+			 struct strbuf *sb,
+			 const char *refname)
+{
+	switch (ref_type(refname)) {
+	case REF_TYPE_PSEUDOREF:
+	case REF_TYPE_PER_WORKTREE:
+		if (wt && !wt->is_current) {
+			if (is_main_worktree(wt))
+				strbuf_addstr(sb, "main-worktree/");
+			else
+				strbuf_addf(sb, "worktrees/%s/", wt->id);
+		}
+		break;
+
+	case REF_TYPE_MAIN_PSEUDOREF:
+	case REF_TYPE_OTHER_PSEUDOREF:
+		break;
+
+	case REF_TYPE_NORMAL:
+		/*
+		 * For shared refs, don't prefix worktrees/ or
+		 * main-worktree/. It's not necessary and
+		 * files-backend.c can't handle it anyway.
+		 */
+		break;
+	}
+	strbuf_addstr(sb, refname);
+}
+
+const char *worktree_ref(const struct worktree *wt, const char *refname)
+{
+	static struct strbuf sb = STRBUF_INIT;
+
+	strbuf_reset(&sb);
+	strbuf_worktree_ref(wt, &sb, refname);
+	return sb.buf;
+}
+
+int other_head_refs(each_ref_fn fn, void *cb_data)
+{
+	struct worktree **worktrees, **p;
+	int ret = 0;
+
+	worktrees = get_worktrees(0);
+	for (p = worktrees; *p; p++) {
+		struct worktree *wt = *p;
+		struct object_id oid;
+		int flag;
+
+		if (wt->is_current)
+			continue;
+
+		if (!refs_read_ref_full(get_main_ref_store(the_repository),
+					worktree_ref(wt, "HEAD"),
+					RESOLVE_REF_READING,
+					&oid, &flag))
+			ret = fn(worktree_ref(wt, "HEAD"), &oid, flag, cb_data);
+		if (ret)
+			break;
+	}
+	free_worktrees(worktrees);
+	return ret;
+}