/src/git/worktree.c

Source
#define USE_THE_REPOSITORY_VARIABLE
#define DISABLE_SIGN_COMPARE_WARNINGS

#include "git-compat-util.h"
#include "abspath.h"
#include "environment.h"
#include "gettext.h"
#include "path.h"
#include "repository.h"
#include "refs.h"
#include "setup.h"
#include "strbuf.h"
#include "worktree.h"
#include "dir.h"
#include "wt-status.h"
#include "config.h"

void free_worktree(struct worktree *worktree)
{
  if (!worktree)
    return;
  free(worktree->path);
  free(worktree->id);
  free(worktree->head_ref);
  free(worktree->lock_reason);
  free(worktree->prune_reason);
  free(worktree);
}

void free_worktrees(struct worktree **worktrees)
{
  int i = 0;
  for (i = 0; worktrees[i]; i++)
    free_worktree(worktrees[i]);
  free (worktrees);
}

/**
 * Update head_oid, 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;
}

static int is_current_worktree(struct worktree *wt)
{
  char *git_dir = absolute_pathdup(repo_get_git_dir(the_repository));
  char *wt_git_dir = get_worktree_git_dir(wt);
  int is_current = !fspathcmp(git_dir, absolute_path(wt_git_dir));
  free(wt_git_dir);
  free(git_dir);
  return is_current;
}

/*
* When in a secondary worktree, and when extensions.worktreeConfig
* is true, only $commondir/config and $commondir/worktrees/<id>/
* config.worktree are consulted, hence any core.bare=true setting in
* $commondir/config.worktree gets overlooked. Thus, check it manually
* to determine if the repository is bare.
*/
static int is_main_worktree_bare(struct repository *repo)
{
  int bare = 0;
  struct config_set cs = {0};
  char *worktree_config = xstrfmt("%s/config.worktree", repo_get_common_dir(repo));

  git_configset_init(&cs);
  git_configset_add_file(&cs, worktree_config);
  git_configset_get_bool(&cs, "core.bare", &bare);

  git_configset_clear(&cs);
  free(worktree_config);
  return bare;
}

/**
 * get the main worktree
 */
static struct worktree *get_main_worktree(int skip_reading_head)
{
  struct worktree *worktree = NULL;
  struct strbuf worktree_path = STRBUF_INIT;

  strbuf_add_real_path(&worktree_path, repo_get_common_dir(the_repository));
  strbuf_strip_suffix(&worktree_path, "/.git");

  CALLOC_ARRAY(worktree, 1);
  worktree->repo = the_repository;
  worktree->path = strbuf_detach(&worktree_path, NULL);
  worktree->is_current = is_current_worktree(worktree);
  worktree->is_bare = (is_bare_repository_cfg == 1) ||
    is_bare_repository() ||
    /*
     * When in a secondary worktree we have to also verify if the main
     * worktree is bare in $commondir/config.worktree.
     * This check is unnecessary if we're currently in the main worktree,
     * as prior checks already consulted all configs of the current worktree.
     */
    (!worktree->is_current && is_main_worktree_bare(the_repository));

  if (!skip_reading_head)
    add_head_info(worktree);
  return worktree;
}

struct worktree *get_linked_worktree(const char *id,
             int skip_reading_head)
{
  struct worktree *worktree = NULL;
  struct strbuf path = STRBUF_INIT;
  struct strbuf worktree_path = STRBUF_INIT;

  if (!id)
    die("Missing linked worktree name");

  repo_common_path_append(the_repository, &path, "worktrees/%s/gitdir", id);
  if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
    /* invalid gitdir file */
    goto done;
  strbuf_rtrim(&worktree_path);
  strbuf_strip_suffix(&worktree_path, "/.git");

  if (!is_absolute_path(worktree_path.buf)) {
    strbuf_strip_suffix(&path, "gitdir");
    strbuf_addbuf(&path, &worktree_path);
    strbuf_realpath_forgiving(&worktree_path, path.buf, 0);
  }

  CALLOC_ARRAY(worktree, 1);
  worktree->repo = the_repository;
  worktree->path = strbuf_detach(&worktree_path, NULL);
  worktree->id = xstrdup(id);
  worktree->is_current = is_current_worktree(worktree);
  if (!skip_reading_head)
    add_head_info(worktree);

done:
  strbuf_release(&path);
  strbuf_release(&worktree_path);
  return worktree;
}

/*
 * NEEDSWORK: This function exists so that we can look up metadata of a
 * worktree without trying to access any of its internals like the refdb. It
 * would be preferable to instead have a corruption-tolerant function for
 * retrieving worktree metadata that could be used when the worktree is known
 * to not be in a healthy state, e.g. when creating or repairing it.
 */
static struct worktree **get_worktrees_internal(int skip_reading_head)
{
  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(skip_reading_head);

  strbuf_addf(&path, "%s/worktrees", repo_get_common_dir(the_repository));
  dir = opendir(path.buf);
  strbuf_release(&path);
  if (dir) {
    while ((d = readdir_skip_dot_and_dotdot(dir)) != NULL) {
      struct worktree *linked = NULL;

      if ((linked = get_linked_worktree(d->d_name, skip_reading_head))) {
        ALLOC_GROW(list, counter + 1, alloc);
        list[counter++] = linked;
      }
    }
    closedir(dir);
  }
  ALLOC_GROW(list, counter + 1, alloc);
  list[counter] = NULL;

  return list;
}

struct worktree **get_worktrees(void)
{
  return get_worktrees_internal(0);
}

struct worktree **get_worktrees_without_reading_head(void)
{
  return get_worktrees_internal(1);
}

char *get_worktree_git_dir(const struct worktree *wt)
{
  if (!wt)
    return xstrdup(repo_get_git_dir(the_repository));
  else if (!wt->id)
    return xstrdup(repo_get_common_dir(the_repository));
  else
    return repo_common_path(the_repository, "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 *to_free = NULL;

  if ((wt = find_worktree_by_suffix(list, arg)))
    return wt;

  if (prefix)
    arg = to_free = prefix_filename(prefix, arg);
  wt = find_worktree_by_path(list, arg);
  free(to_free);
  return wt;
}

struct worktree *find_worktree_by_path(struct worktree **list, const char *p)
{
  struct strbuf wt_path = STRBUF_INIT;
  char *path = real_pathdup(p, 0);

  if (!path)
    return NULL;
  for (; *list; list++) {
    if (!strbuf_realpath(&wt_path, (*list)->path, 0))
      continue;

    if (!fspathcmp(path, wt_path.buf))
      break;
  }
  free(path);
  strbuf_release(&wt_path);
  return *list;
}

int is_main_worktree(const struct worktree *wt)
{
  return !wt->id;
}

const char *worktree_lock_reason(struct worktree *wt)
{
  if (is_main_worktree(wt))
    return NULL;

  if (!wt->lock_reason_valid) {
    struct strbuf path = STRBUF_INIT;

    strbuf_addstr(&path, worktree_git_path(the_repository, 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;
}

const char *worktree_prune_reason(struct worktree *wt, timestamp_t expire)
{
  struct strbuf reason = STRBUF_INIT;
  char *path = NULL;

  if (is_main_worktree(wt))
    return NULL;
  if (wt->prune_reason_valid)
    return wt->prune_reason;

  if (should_prune_worktree(wt->id, &reason, &path, expire))
    wt->prune_reason = strbuf_detach(&reason, NULL);
  wt->prune_reason_valid = 1;

  strbuf_release(&reason);
  free(path);
  return wt->prune_reason;
}

/* convenient wrapper to deal with NULL strbuf */
__attribute__((format (printf, 2, 3)))
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;
  struct strbuf realpath = STRBUF_INIT;
  struct strbuf buf = 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"),
           repo_common_path_replace(the_repository, &buf, "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;
  }

  strbuf_realpath(&realpath, repo_common_path_replace(the_repository, &buf, "worktrees/%s", wt->id), 1);
  ret = fspathcmp(path, realpath.buf);

  if (ret)
    strbuf_addf_gently(errmsg, _("'%s' does not point back to '%s'"),
           wt->path, repo_common_path_replace(the_repository, &buf,
                      "worktrees/%s", wt->id));
done:
  free(path);
  strbuf_release(&buf);
  strbuf_release(&wt_path);
  strbuf_release(&realpath);
  return ret;
}

void update_worktree_location(struct worktree *wt, const char *path_,
            int use_relative_paths)
{
  struct strbuf path = STRBUF_INIT;
  struct strbuf dotgit = STRBUF_INIT;
  struct strbuf gitdir = STRBUF_INIT;
  char *wt_gitdir;

  if (is_main_worktree(wt))
    BUG("can't relocate main worktree");

  wt_gitdir = repo_common_path(the_repository, "worktrees/%s/gitdir", wt->id);
  strbuf_realpath(&gitdir, wt_gitdir, 1);
  strbuf_realpath(&path, path_, 1);
  strbuf_addf(&dotgit, "%s/.git", path.buf);
  if (fspathcmp(wt->path, path.buf)) {
    write_worktree_linking_files(dotgit, gitdir, use_relative_paths);

    free(wt->path);
    wt->path = strbuf_detach(&path, NULL);
  }
  strbuf_release(&path);
  strbuf_release(&dotgit);
  strbuf_release(&gitdir);
  free(wt_gitdir);
}

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 &&
           skip_prefix(target, "refs/heads/", &target) &&
           !strcmp(state.branch, target);
  wt_status_state_free_buffers(&state);
  return found_rebase;
}

int is_worktree_being_bisected(const struct worktree *wt,
             const char *target)
{
  struct wt_status_state state;
  int found_bisect;

  memset(&state, 0, sizeof(state));
  found_bisect = wt_status_check_bisect(wt, &state) &&
           state.bisecting_from &&
           skip_prefix(target, "refs/heads/", &target) &&
           !strcmp(state.bisecting_from, target);
  wt_status_state_free_buffers(&state);
  return found_bisect;
}

/*
 * 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.
 */
int is_shared_symref(const struct worktree *wt, const char *symref,
         const char *target)
{
  const char *symref_target;
  struct ref_store *refs;
  int flags;

  if (wt->is_bare)
    return 0;

  if (wt->is_detached && !strcmp(symref, "HEAD")) {
    if (is_worktree_being_rebased(wt, target))
      return 1;
    if (is_worktree_being_bisected(wt, target))
      return 1;
  }

  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))
    return 1;

  return 0;
}

const struct worktree *find_shared_symref(struct worktree **worktrees,
            const char *symref,
            const char *target)
{

  for (int i = 0; worktrees[i]; i++)
    if (is_shared_symref(worktrees[i], symref, target))
      return worktrees[i];

  return NULL;
}

int submodule_uses_worktrees(const char *path)
{
  char *submodule_gitdir;
  struct strbuf sb = STRBUF_INIT, err = STRBUF_INIT;
  DIR *dir;
  struct dirent *d;
  int ret = 0;
  struct repository_format format = REPOSITORY_FORMAT_INIT;

  submodule_gitdir = repo_submodule_path(the_repository,
                 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);

  strbuf_addstr(&sb, "/config");
  read_repository_format(&format, sb.buf);
  if (verify_repository_format(&format, &err)) {
    strbuf_release(&err);
    strbuf_release(&sb);
    clear_repository_format(&format);
    return 1;
  }
  clear_repository_format(&format);
  strbuf_release(&err);

  /* 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;

  d = readdir_skip_dot_and_dotdot(dir);
  if (d)
    ret = 1;
  closedir(dir);
  return ret;
}

void strbuf_worktree_ref(const struct worktree *wt,
       struct strbuf *sb,
       const char *refname)
{
  if (parse_worktree_ref(refname, NULL, NULL, NULL) ==
        REF_WORKTREE_CURRENT &&
      wt && !wt->is_current) {
    if (is_main_worktree(wt))
      strbuf_addstr(sb, "main-worktree/");
    else
      strbuf_addf(sb, "worktrees/%s/", wt->id);
  }
  strbuf_addstr(sb, refname);
}

int other_head_refs(each_ref_fn fn, void *cb_data)
{
  struct worktree **worktrees, **p;
  struct strbuf refname = STRBUF_INIT;
  int ret = 0;

  worktrees = get_worktrees();
  for (p = worktrees; *p; p++) {
    struct worktree *wt = *p;
    struct object_id oid;
    int flag;

    if (wt->is_current)
      continue;

    strbuf_reset(&refname);
    strbuf_worktree_ref(wt, &refname, "HEAD");
    if (refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
              refname.buf,
              RESOLVE_REF_READING,
              &oid, &flag)) {
      struct reference ref = {
        .name = refname.buf,
        .oid = &oid,
        .flags = flag,
      };

      ret = fn(&ref, cb_data);
    }
    if (ret)
      break;
  }
  free_worktrees(worktrees);
  strbuf_release(&refname);
  return ret;
}

/*
 * Repair worktree's /path/to/worktree/.git file if missing, corrupt, or not
 * pointing at <repo>/worktrees/<id>.
 */
static void repair_gitfile(struct worktree *wt,
         worktree_repair_fn fn, void *cb_data,
         int use_relative_paths)
{
  struct strbuf dotgit = STRBUF_INIT;
  struct strbuf gitdir = STRBUF_INIT;
  struct strbuf repo = STRBUF_INIT;
  struct strbuf backlink = STRBUF_INIT;
  char *dotgit_contents = NULL;
  const char *repair = NULL;
  char *path = NULL;
  int err;

  /* missing worktree can't be repaired */
  if (!file_exists(wt->path))
    goto done;

  if (!is_directory(wt->path)) {
    fn(1, wt->path, _("not a directory"), cb_data);
    goto done;
  }

  path = repo_common_path(the_repository, "worktrees/%s", wt->id);
  strbuf_realpath(&repo, path, 1);
  strbuf_addf(&dotgit, "%s/.git", wt->path);
  strbuf_addf(&gitdir, "%s/gitdir", repo.buf);
  dotgit_contents = xstrdup_or_null(read_gitfile_gently(dotgit.buf, &err));

  if (dotgit_contents) {
    if (is_absolute_path(dotgit_contents)) {
      strbuf_addstr(&backlink, dotgit_contents);
    } else {
      strbuf_addf(&backlink, "%s/%s", wt->path, dotgit_contents);
      strbuf_realpath_forgiving(&backlink, backlink.buf, 0);
    }
  }

  if (err == READ_GITFILE_ERR_NOT_A_FILE)
    fn(1, wt->path, _(".git is not a file"), cb_data);
  else if (err)
    repair = _(".git file broken");
  else if (fspathcmp(backlink.buf, repo.buf))
    repair = _(".git file incorrect");
  else if (use_relative_paths == is_absolute_path(dotgit_contents))
    repair = _(".git file absolute/relative path mismatch");

  if (repair) {
    fn(0, wt->path, repair, cb_data);
    write_worktree_linking_files(dotgit, gitdir, use_relative_paths);
  }

done:
  free(dotgit_contents);
  free(path);
  strbuf_release(&repo);
  strbuf_release(&dotgit);
  strbuf_release(&gitdir);
  strbuf_release(&backlink);
}

static void repair_noop(int iserr UNUSED,
      const char *path UNUSED,
      const char *msg UNUSED,
      void *cb_data UNUSED)
{
  /* nothing */
}

void repair_worktrees(worktree_repair_fn fn, void *cb_data, int use_relative_paths)
{
  struct worktree **worktrees = get_worktrees_internal(1);
  struct worktree **wt = worktrees + 1; /* +1 skips main worktree */

  if (!fn)
    fn = repair_noop;
  for (; *wt; wt++)
    repair_gitfile(*wt, fn, cb_data, use_relative_paths);
  free_worktrees(worktrees);
}

void repair_worktree_after_gitdir_move(struct worktree *wt, const char *old_path)
{
  struct strbuf gitdir = STRBUF_INIT;
  struct strbuf dotgit = STRBUF_INIT;
  int is_relative_path;
  char *path = NULL;

  if (is_main_worktree(wt))
    goto done;

  path = repo_common_path(the_repository, "worktrees/%s/gitdir", wt->id);
  strbuf_realpath(&gitdir, path, 1);

  if (strbuf_read_file(&dotgit, gitdir.buf, 0) < 0)
    goto done;

  strbuf_rtrim(&dotgit);
  is_relative_path = ! is_absolute_path(dotgit.buf);
  if (is_relative_path) {
    strbuf_insertf(&dotgit, 0, "%s/worktrees/%s/", old_path, wt->id);
    strbuf_realpath_forgiving(&dotgit, dotgit.buf, 0);
  }

  if (!file_exists(dotgit.buf))
    goto done;

  write_worktree_linking_files(dotgit, gitdir, is_relative_path);
done:
  strbuf_release(&gitdir);
  strbuf_release(&dotgit);
  free(path);
}

void repair_worktrees_after_gitdir_move(const char *old_path)
{
  struct worktree **worktrees = get_worktrees_internal(1);
  struct worktree **wt = worktrees + 1; /* +1 skips main worktree */

  for (; *wt; wt++)
    repair_worktree_after_gitdir_move(*wt, old_path);
  free_worktrees(worktrees);
}

static int is_main_worktree_path(const char *path)
{
  struct strbuf target = STRBUF_INIT;
  struct strbuf maindir = STRBUF_INIT;
  int cmp;

  strbuf_add_real_path(&target, path);
  strbuf_strip_suffix(&target, "/.git");
  strbuf_add_real_path(&maindir, repo_get_common_dir(the_repository));
  strbuf_strip_suffix(&maindir, "/.git");
  cmp = fspathcmp(maindir.buf, target.buf);

  strbuf_release(&maindir);
  strbuf_release(&target);
  return !cmp;
}

/*
 * If both the main worktree and linked worktree have been moved, then the
 * gitfile /path/to/worktree/.git won't point into the repository, thus we
 * won't know which <repo>/worktrees/<id>/gitdir to repair. However, we may
 * be able to infer the gitdir by manually reading /path/to/worktree/.git,
 * extracting the <id>, and checking if <repo>/worktrees/<id> exists.
 *
 * Returns -1 on failure and strbuf.len on success.
 */
static ssize_t infer_backlink(const char *gitfile, struct strbuf *inferred)
{
  struct strbuf actual = STRBUF_INIT;
  const char *id;

  if (strbuf_read_file(&actual, gitfile, 0) < 0)
    goto error;
  if (!starts_with(actual.buf, "gitdir:"))
    goto error;
  if (!(id = find_last_dir_sep(actual.buf)))
    goto error;
  strbuf_trim(&actual);
  id++; /* advance past '/' to point at <id> */
  if (!*id)
    goto error;
  repo_common_path_replace(the_repository, inferred, "worktrees/%s", id);
  if (!is_directory(inferred->buf))
    goto error;

  strbuf_release(&actual);
  return inferred->len;
error:
  strbuf_release(&actual);
  strbuf_reset(inferred); /* clear invalid path */
  return -1;
}

/*
 * Repair <repo>/worktrees/<id>/gitdir if missing, corrupt, or not pointing at
 * the worktree's path.
 */
void repair_worktree_at_path(const char *path,
           worktree_repair_fn fn, void *cb_data,
           int use_relative_paths)
{
  struct strbuf dotgit = STRBUF_INIT;
  struct strbuf backlink = STRBUF_INIT;
  struct strbuf inferred_backlink = STRBUF_INIT;
  struct strbuf gitdir = STRBUF_INIT;
  struct strbuf olddotgit = STRBUF_INIT;
  char *dotgit_contents = NULL;
  const char *repair = NULL;
  int err;

  if (!fn)
    fn = repair_noop;

  if (is_main_worktree_path(path))
    goto done;

  strbuf_addf(&dotgit, "%s/.git", path);
  if (!strbuf_realpath(&dotgit, dotgit.buf, 0)) {
    fn(1, path, _("not a valid path"), cb_data);
    goto done;
  }

  infer_backlink(dotgit.buf, &inferred_backlink);
  strbuf_realpath_forgiving(&inferred_backlink, inferred_backlink.buf, 0);
  dotgit_contents = xstrdup_or_null(read_gitfile_gently(dotgit.buf, &err));
  if (dotgit_contents) {
    if (is_absolute_path(dotgit_contents)) {
      strbuf_addstr(&backlink, dotgit_contents);
    } else {
      strbuf_addbuf(&backlink, &dotgit);
      strbuf_strip_suffix(&backlink, ".git");
      strbuf_addstr(&backlink, dotgit_contents);
      strbuf_realpath_forgiving(&backlink, backlink.buf, 0);
    }
  } else if (err == READ_GITFILE_ERR_NOT_A_FILE) {
    fn(1, dotgit.buf, _("unable to locate repository; .git is not a file"), cb_data);
    goto done;
  } else if (err == READ_GITFILE_ERR_NOT_A_REPO) {
    if (inferred_backlink.len) {
      /*
       * Worktree's .git file does not point at a repository
       * but we found a .git/worktrees/<id> in this
       * repository with the same <id> as recorded in the
       * worktree's .git file so make the worktree point at
       * the discovered .git/worktrees/<id>.
       */
      strbuf_swap(&backlink, &inferred_backlink);
    } else {
      fn(1, dotgit.buf, _("unable to locate repository; .git file does not reference a repository"), cb_data);
      goto done;
    }
  } else {
    fn(1, dotgit.buf, _("unable to locate repository; .git file broken"), cb_data);
    goto done;
  }

  /*
   * If we got this far, either the worktree's .git file pointed at a
   * valid repository (i.e. read_gitfile_gently() returned success) or
   * the .git file did not point at a repository but we were able to
   * infer a suitable new value for the .git file by locating a
   * .git/worktrees/<id> in *this* repository corresponding to the <id>
   * recorded in the worktree's .git file.
   *
   * However, if, at this point, inferred_backlink is non-NULL (i.e. we
   * found a suitable .git/worktrees/<id> in *this* repository) *and* the
   * worktree's .git file points at a valid repository *and* those two
   * paths differ, then that indicates that the user probably *copied*
   * the main and linked worktrees to a new location as a unit rather
   * than *moving* them. Thus, the copied worktree's .git file actually
   * points at the .git/worktrees/<id> in the *original* repository, not
   * in the "copy" repository. In this case, point the "copy" worktree's
   * .git file at the "copy" repository.
   */
  if (inferred_backlink.len && fspathcmp(backlink.buf, inferred_backlink.buf))
    strbuf_swap(&backlink, &inferred_backlink);

  strbuf_addf(&gitdir, "%s/gitdir", backlink.buf);
  if (strbuf_read_file(&olddotgit, gitdir.buf, 0) < 0)
    repair = _("gitdir unreadable");
  else if (use_relative_paths == is_absolute_path(olddotgit.buf))
    repair = _("gitdir absolute/relative path mismatch");
  else {
    strbuf_rtrim(&olddotgit);
    if (!is_absolute_path(olddotgit.buf)) {
      strbuf_insertf(&olddotgit, 0, "%s/", backlink.buf);
      strbuf_realpath_forgiving(&olddotgit, olddotgit.buf, 0);
    }
    if (fspathcmp(olddotgit.buf, dotgit.buf))
      repair = _("gitdir incorrect");
  }

  if (repair) {
    fn(0, gitdir.buf, repair, cb_data);
    write_worktree_linking_files(dotgit, gitdir, use_relative_paths);
  }
done:
  free(dotgit_contents);
  strbuf_release(&olddotgit);
  strbuf_release(&backlink);
  strbuf_release(&inferred_backlink);
  strbuf_release(&gitdir);
  strbuf_release(&dotgit);
}

int should_prune_worktree(const char *id, struct strbuf *reason, char **wtpath, timestamp_t expire)
{
  struct stat st;
  struct strbuf dotgit = STRBUF_INIT;
  struct strbuf gitdir = STRBUF_INIT;
  struct strbuf repo = STRBUF_INIT;
  struct strbuf file = STRBUF_INIT;
  char *path = NULL;
  int rc = 0;
  int fd;
  size_t len;
  ssize_t read_result;

  *wtpath = NULL;

  path = repo_common_path(the_repository, "worktrees/%s", id);
  strbuf_realpath(&repo, path, 1);
  FREE_AND_NULL(path);

  strbuf_addf(&gitdir, "%s/gitdir", repo.buf);
  if (!is_directory(repo.buf)) {
    strbuf_addstr(reason, _("not a valid directory"));
    rc = 1;
    goto done;
  }
  strbuf_addf(&file, "%s/locked", repo.buf);
  if (file_exists(file.buf)) {
    goto done;
  }
  if (stat(gitdir.buf, &st)) {
    strbuf_addstr(reason, _("gitdir file does not exist"));
    rc = 1;
    goto done;
  }
  fd = open(gitdir.buf, O_RDONLY);
  if (fd < 0) {
    strbuf_addf(reason, _("unable to read gitdir file (%s)"),
          strerror(errno));
    rc = 1;
    goto done;
  }
  len = xsize_t(st.st_size);
  path = xmallocz(len);

  read_result = read_in_full(fd, path, len);
  close(fd);
  if (read_result < 0) {
    strbuf_addf(reason, _("unable to read gitdir file (%s)"),
          strerror(errno));
    rc = 1;
    goto done;
  } else if (read_result != len) {
    strbuf_addf(reason,
          _("short read (expected %"PRIuMAX" bytes, read %"PRIuMAX")"),
          (uintmax_t)len, (uintmax_t)read_result);
    rc = 1;
    goto done;
  }
  while (len && (path[len - 1] == '\n' || path[len - 1] == '\r'))
    len--;
  if (!len) {
    strbuf_addstr(reason, _("invalid gitdir file"));
    rc = 1;
    goto done;
  }
  path[len] = '\0';
  if (is_absolute_path(path)) {
    strbuf_addstr(&dotgit, path);
  } else {
    strbuf_addf(&dotgit, "%s/%s", repo.buf, path);
    strbuf_realpath_forgiving(&dotgit, dotgit.buf, 0);
  }
  if (!file_exists(dotgit.buf)) {
    strbuf_reset(&file);
    strbuf_addf(&file, "%s/index", repo.buf);
    if (stat(file.buf, &st) || st.st_mtime <= expire) {
      strbuf_addstr(reason, _("gitdir file points to non-existent location"));
      rc = 1;
      goto done;
    }
  }
  *wtpath = strbuf_detach(&dotgit, NULL);
done:
  free(path);
  strbuf_release(&dotgit);
  strbuf_release(&gitdir);
  strbuf_release(&repo);
  strbuf_release(&file);
  return rc;
}

static int move_config_setting(const char *key, const char *value,
             const char *from_file, const char *to_file)
{
  if (repo_config_set_in_file_gently(the_repository, to_file, key, NULL, value))
    return error(_("unable to set %s in '%s'"), key, to_file);
  if (repo_config_set_in_file_gently(the_repository, from_file, key, NULL, NULL))
    return error(_("unable to unset %s in '%s'"), key, from_file);
  return 0;
}

int init_worktree_config(struct repository *r)
{
  int res = 0;
  int bare = 0;
  struct config_set cs = { { 0 } };
  const char *core_worktree;
  char *common_config_file;
  char *main_worktree_file;

  /*
   * If the extension is already enabled, then we can skip the
   * upgrade process.
   */
  if (r->repository_format_worktree_config)
    return 0;
  if ((res = repo_config_set_gently(the_repository, "extensions.worktreeConfig", "true")))
    return error(_("failed to set extensions.worktreeConfig setting"));

  common_config_file = xstrfmt("%s/config", r->commondir);
  main_worktree_file = xstrfmt("%s/config.worktree", r->commondir);

  git_configset_init(&cs);
  git_configset_add_file(&cs, common_config_file);

  /*
   * If core.bare is true in the common config file, then we need to
   * move it to the main worktree's config file or it will break all
   * worktrees. If it is false, then leave it in place because it
   * _could_ be negating a global core.bare=true.
   */
  if (!git_configset_get_bool(&cs, "core.bare", &bare) && bare) {
    if ((res = move_config_setting("core.bare", "true",
                 common_config_file,
                 main_worktree_file)))
      goto cleanup;
  }
  /*
   * If core.worktree is set, then the main worktree is located
   * somewhere different than the parent of the common Git dir.
   * Relocate that value to avoid breaking all worktrees with this
   * upgrade to worktree config.
   */
  if (!git_configset_get_value(&cs, "core.worktree", &core_worktree, NULL)) {
    if ((res = move_config_setting("core.worktree", core_worktree,
                 common_config_file,
                 main_worktree_file)))
      goto cleanup;
  }

  /*
   * Ensure that we use worktree config for the remaining lifetime
   * of the current process.
   */
  r->repository_format_worktree_config = 1;

cleanup:
  git_configset_clear(&cs);
  free(common_config_file);
  free(main_worktree_file);
  return res;
}

void write_worktree_linking_files(struct strbuf dotgit, struct strbuf gitdir,
          int use_relative_paths)
{
  struct strbuf path = STRBUF_INIT;
  struct strbuf repo = STRBUF_INIT;
  struct strbuf tmp = STRBUF_INIT;

  strbuf_addbuf(&path, &dotgit);
  strbuf_strip_suffix(&path, "/.git");
  strbuf_realpath(&path, path.buf, 1);
  strbuf_addbuf(&repo, &gitdir);
  strbuf_strip_suffix(&repo, "/gitdir");
  strbuf_realpath(&repo, repo.buf, 1);

  if (use_relative_paths && !the_repository->repository_format_relative_worktrees) {
    if (upgrade_repository_format(1) < 0)
      die(_("unable to upgrade repository format to support relative worktrees"));
    if (repo_config_set_gently(the_repository, "extensions.relativeWorktrees", "true"))
      die(_("unable to set extensions.relativeWorktrees setting"));
    the_repository->repository_format_relative_worktrees = 1;
  }

  if (use_relative_paths) {
    write_file(gitdir.buf, "%s/.git", relative_path(path.buf, repo.buf, &tmp));
    write_file(dotgit.buf, "gitdir: %s", relative_path(repo.buf, path.buf, &tmp));
  } else {
    write_file(gitdir.buf, "%s/.git", path.buf);
    write_file(dotgit.buf, "gitdir: %s", repo.buf);
  }

  strbuf_release(&path);
  strbuf_release(&repo);
  strbuf_release(&tmp);
}

Coverage Report

Created: 2025-12-31 07:01