/src/git/remote.c

Source
#define USE_THE_REPOSITORY_VARIABLE
#define DISABLE_SIGN_COMPARE_WARNINGS

#include "git-compat-util.h"
#include "abspath.h"
#include "config.h"
#include "environment.h"
#include "gettext.h"
#include "hex.h"
#include "remote.h"
#include "urlmatch.h"
#include "refs.h"
#include "refspec.h"
#include "object-name.h"
#include "odb.h"
#include "path.h"
#include "commit.h"
#include "diff.h"
#include "revision.h"
#include "dir.h"
#include "setup.h"
#include "string-list.h"
#include "strvec.h"
#include "commit-reach.h"
#include "advice.h"
#include "connect.h"
#include "parse-options.h"
#include "transport.h"

enum map_direction { FROM_SRC, FROM_DST };

enum {
  ENABLE_ADVICE_PULL       = (1 << 0),
  ENABLE_ADVICE_PUSH       = (1 << 1),
  ENABLE_ADVICE_DIVERGENCE = (1 << 2),
};

struct counted_string {
  size_t len;
  const char *s;
};

static int valid_remote(const struct remote *remote)
{
  return !!remote->url.nr;
}

static char *alias_url(const char *url, struct rewrites *r)
{
  int i, j;
  struct counted_string *longest;
  int longest_i;

  longest = NULL;
  longest_i = -1;
  for (i = 0; i < r->rewrite_nr; i++) {
    if (!r->rewrite[i])
      continue;
    for (j = 0; j < r->rewrite[i]->instead_of_nr; j++) {
      if (starts_with(url, r->rewrite[i]->instead_of[j].s) &&
          (!longest ||
           longest->len < r->rewrite[i]->instead_of[j].len)) {
        longest = &(r->rewrite[i]->instead_of[j]);
        longest_i = i;
      }
    }
  }
  if (!longest)
    return NULL;

  return xstrfmt("%s%s", r->rewrite[longest_i]->base, url + longest->len);
}

static void add_url(struct remote *remote, const char *url)
{
  if (*url)
    strvec_push(&remote->url, url);
  else
    strvec_clear(&remote->url);
}

static void add_pushurl(struct remote *remote, const char *pushurl)
{
  if (*pushurl)
    strvec_push(&remote->pushurl, pushurl);
  else
    strvec_clear(&remote->pushurl);
}

static void add_pushurl_alias(struct remote_state *remote_state,
            struct remote *remote, const char *url)
{
  char *alias = alias_url(url, &remote_state->rewrites_push);
  if (alias)
    add_pushurl(remote, alias);
  free(alias);
}

static void add_url_alias(struct remote_state *remote_state,
        struct remote *remote, const char *url)
{
  char *alias = alias_url(url, &remote_state->rewrites);
  add_url(remote, alias ? alias : url);
  add_pushurl_alias(remote_state, remote, url);
  free(alias);
}

struct remotes_hash_key {
  const char *str;
  int len;
};

static int remotes_hash_cmp(const void *cmp_data UNUSED,
          const struct hashmap_entry *eptr,
          const struct hashmap_entry *entry_or_key,
          const void *keydata)
{
  const struct remote *a, *b;
  const struct remotes_hash_key *key = keydata;

  a = container_of(eptr, const struct remote, ent);
  b = container_of(entry_or_key, const struct remote, ent);

  if (key)
    return !!xstrncmpz(a->name, key->str, key->len);
  else
    return strcmp(a->name, b->name);
}

static struct remote *make_remote(struct remote_state *remote_state,
          const char *name, int len)
{
  struct remote *ret;
  struct remotes_hash_key lookup;
  struct hashmap_entry lookup_entry, *e;

  if (!len)
    len = strlen(name);

  lookup.str = name;
  lookup.len = len;
  hashmap_entry_init(&lookup_entry, memhash(name, len));

  e = hashmap_get(&remote_state->remotes_hash, &lookup_entry, &lookup);
  if (e)
    return container_of(e, struct remote, ent);

  CALLOC_ARRAY(ret, 1);
  ret->prune = -1;  /* unspecified */
  ret->prune_tags = -1;  /* unspecified */
  ret->name = xstrndup(name, len);
  refspec_init_push(&ret->push);
  refspec_init_fetch(&ret->fetch);
  string_list_init_dup(&ret->server_options);

  ALLOC_GROW(remote_state->remotes, remote_state->remotes_nr + 1,
       remote_state->remotes_alloc);
  remote_state->remotes[remote_state->remotes_nr++] = ret;

  hashmap_entry_init(&ret->ent, lookup_entry.hash);
  if (hashmap_put_entry(&remote_state->remotes_hash, ret, ent))
    BUG("hashmap_put overwrote entry after hashmap_get returned NULL");
  return ret;
}

static void remote_clear(struct remote *remote)
{
  free((char *)remote->name);
  free((char *)remote->foreign_vcs);

  strvec_clear(&remote->url);
  strvec_clear(&remote->pushurl);

  refspec_clear(&remote->push);
  refspec_clear(&remote->fetch);

  free((char *)remote->receivepack);
  free((char *)remote->uploadpack);
  FREE_AND_NULL(remote->http_proxy);
  FREE_AND_NULL(remote->http_proxy_authmethod);
  string_list_clear(&remote->server_options, 0);
}

static void add_merge(struct branch *branch, const char *name)
{
  struct refspec_item *merge;

  ALLOC_GROW(branch->merge, branch->merge_nr + 1,
       branch->merge_alloc);

  merge = xcalloc(1, sizeof(*merge));
  merge->src = xstrdup(name);

  branch->merge[branch->merge_nr++] = merge;
}

struct branches_hash_key {
  const char *str;
  int len;
};

static int branches_hash_cmp(const void *cmp_data UNUSED,
           const struct hashmap_entry *eptr,
           const struct hashmap_entry *entry_or_key,
           const void *keydata)
{
  const struct branch *a, *b;
  const struct branches_hash_key *key = keydata;

  a = container_of(eptr, const struct branch, ent);
  b = container_of(entry_or_key, const struct branch, ent);

  if (key)
    return !!xstrncmpz(a->name, key->str, key->len);
  else
    return strcmp(a->name, b->name);
}

static struct branch *find_branch(struct remote_state *remote_state,
          const char *name, size_t len)
{
  struct branches_hash_key lookup;
  struct hashmap_entry lookup_entry, *e;

  lookup.str = name;
  lookup.len = len;
  hashmap_entry_init(&lookup_entry, memhash(name, len));

  e = hashmap_get(&remote_state->branches_hash, &lookup_entry, &lookup);
  if (e)
    return container_of(e, struct branch, ent);

  return NULL;
}

static void die_on_missing_branch(struct repository *repo,
          struct branch *branch)
{
  /* branch == NULL is always valid because it represents detached HEAD. */
  if (branch &&
      branch != find_branch(repo->remote_state, branch->name,
          strlen(branch->name)))
    die("branch %s was not found in the repository", branch->name);
}

static struct branch *make_branch(struct remote_state *remote_state,
          const char *name, size_t len)
{
  struct branch *ret;

  ret = find_branch(remote_state, name, len);
  if (ret)
    return ret;

  CALLOC_ARRAY(ret, 1);
  ret->name = xstrndup(name, len);
  ret->refname = xstrfmt("refs/heads/%s", ret->name);

  hashmap_entry_init(&ret->ent, memhash(name, len));
  if (hashmap_put_entry(&remote_state->branches_hash, ret, ent))
    BUG("hashmap_put overwrote entry after hashmap_get returned NULL");
  return ret;
}

static void merge_clear(struct branch *branch)
{
  for (int i = 0; i < branch->merge_nr; i++) {
    refspec_item_clear(branch->merge[i]);
    free(branch->merge[i]);
  }
  FREE_AND_NULL(branch->merge);
  branch->merge_nr = 0;
}

static void branch_release(struct branch *branch)
{
  free((char *)branch->name);
  free((char *)branch->refname);
  free(branch->remote_name);
  free(branch->pushremote_name);
  free(branch->push_tracking_ref);
  merge_clear(branch);
}

static struct rewrite *make_rewrite(struct rewrites *r,
            const char *base, size_t len)
{
  struct rewrite *ret;
  int i;

  for (i = 0; i < r->rewrite_nr; i++) {
    if (len == r->rewrite[i]->baselen &&
        !strncmp(base, r->rewrite[i]->base, len))
      return r->rewrite[i];
  }

  ALLOC_GROW(r->rewrite, r->rewrite_nr + 1, r->rewrite_alloc);
  CALLOC_ARRAY(ret, 1);
  r->rewrite[r->rewrite_nr++] = ret;
  ret->base = xstrndup(base, len);
  ret->baselen = len;
  return ret;
}

static void rewrites_release(struct rewrites *r)
{
  for (int i = 0; i < r->rewrite_nr; i++)
    free((char *)r->rewrite[i]->base);
  free(r->rewrite);
  memset(r, 0, sizeof(*r));
}

static void add_instead_of(struct rewrite *rewrite, const char *instead_of)
{
  ALLOC_GROW(rewrite->instead_of, rewrite->instead_of_nr + 1, rewrite->instead_of_alloc);
  rewrite->instead_of[rewrite->instead_of_nr].s = instead_of;
  rewrite->instead_of[rewrite->instead_of_nr].len = strlen(instead_of);
  rewrite->instead_of_nr++;
}

#ifndef WITH_BREAKING_CHANGES
static const char *skip_spaces(const char *s)
{
  while (isspace(*s))
    s++;
  return s;
}

static void warn_about_deprecated_remote_type(const char *type,
                const struct remote *remote)
{
  warning(_("reading remote from \"%s/%s\", which is nominated for removal.\n"
      "\n"
      "If you still use the \"remotes/\" directory it is recommended to\n"
      "migrate to config-based remotes:\n"
      "\n"
      "\tgit remote rename %s %s\n"
      "\n"
      "If you cannot, please let us know why you still need to use it by\n"
      "sending an e-mail to <git@vger.kernel.org>."),
    type, remote->name, remote->name, remote->name);
}

static void read_remotes_file(struct repository *repo, struct remote *remote)
{
  struct strbuf buf = STRBUF_INIT;
  FILE *f = fopen_or_warn(repo_git_path_append(repo, &buf,
                 "remotes/%s", remote->name), "r");

  if (!f)
    goto out;

  warn_about_deprecated_remote_type("remotes", remote);

  remote->configured_in_repo = 1;
  remote->origin = REMOTE_REMOTES;
  while (strbuf_getline(&buf, f) != EOF) {
    const char *v;

    strbuf_rtrim(&buf);

    if (skip_prefix(buf.buf, "URL:", &v))
      add_url_alias(repo->remote_state, remote,
              skip_spaces(v));
    else if (skip_prefix(buf.buf, "Push:", &v))
      refspec_append(&remote->push, skip_spaces(v));
    else if (skip_prefix(buf.buf, "Pull:", &v))
      refspec_append(&remote->fetch, skip_spaces(v));
  }
  fclose(f);

out:
  strbuf_release(&buf);
}

static void read_branches_file(struct repository *repo, struct remote *remote)
{
  char *frag, *to_free = NULL;
  struct strbuf buf = STRBUF_INIT;
  FILE *f = fopen_or_warn(repo_git_path_append(repo, &buf,
                 "branches/%s", remote->name), "r");

  if (!f)
    goto out;

  warn_about_deprecated_remote_type("branches", remote);

  strbuf_getline_lf(&buf, f);
  fclose(f);
  strbuf_trim(&buf);
  if (!buf.len)
    goto out;

  remote->configured_in_repo = 1;
  remote->origin = REMOTE_BRANCHES;

  /*
   * The branches file would have URL and optionally
   * #branch specified.  The default (or specified) branch is
   * fetched and stored in the local branch matching the
   * remote name.
   */
  frag = strchr(buf.buf, '#');
  if (frag)
    *(frag++) = '\0';
  else
    frag = to_free = repo_default_branch_name(repo, 0);

  add_url_alias(repo->remote_state, remote, buf.buf);
  refspec_appendf(&remote->fetch, "refs/heads/%s:refs/heads/%s",
      frag, remote->name);

  /*
   * Cogito compatible push: push current HEAD to remote #branch
   * (master if missing)
   */
  refspec_appendf(&remote->push, "HEAD:refs/heads/%s", frag);
  remote->fetch_tags = 1; /* always auto-follow */

out:
  strbuf_release(&buf);
  free(to_free);
}
#endif /* WITH_BREAKING_CHANGES */

static int handle_config(const char *key, const char *value,
       const struct config_context *ctx, void *cb)
{
  const char *name;
  size_t namelen;
  const char *subkey;
  struct remote *remote;
  struct branch *branch;
  struct remote_state *remote_state = cb;
  const struct key_value_info *kvi = ctx->kvi;

  if (parse_config_key(key, "branch", &name, &namelen, &subkey) >= 0) {
    /* There is no subsection. */
    if (!name)
      return 0;
    /* There is a subsection, but it is empty. */
    if (!namelen)
      return -1;
    branch = make_branch(remote_state, name, namelen);
    if (!strcmp(subkey, "remote")) {
      FREE_AND_NULL(branch->remote_name);
      return git_config_string(&branch->remote_name, key, value);
    } else if (!strcmp(subkey, "pushremote")) {
      FREE_AND_NULL(branch->pushremote_name);
      return git_config_string(&branch->pushremote_name, key, value);
    } else if (!strcmp(subkey, "merge")) {
      if (!value)
        return config_error_nonbool(key);
      add_merge(branch, value);
    }
    return 0;
  }
  if (parse_config_key(key, "url", &name, &namelen, &subkey) >= 0) {
    struct rewrite *rewrite;
    if (!name)
      return 0;
    if (!strcmp(subkey, "insteadof")) {
      if (!value)
        return config_error_nonbool(key);
      rewrite = make_rewrite(&remote_state->rewrites, name,
                 namelen);
      add_instead_of(rewrite, xstrdup(value));
    } else if (!strcmp(subkey, "pushinsteadof")) {
      if (!value)
        return config_error_nonbool(key);
      rewrite = make_rewrite(&remote_state->rewrites_push,
                 name, namelen);
      add_instead_of(rewrite, xstrdup(value));
    }
  }

  if (parse_config_key(key, "remote", &name, &namelen, &subkey) < 0)
    return 0;

  /* Handle remote.* variables */
  if (!name && !strcmp(subkey, "pushdefault")) {
    FREE_AND_NULL(remote_state->pushremote_name);
    return git_config_string(&remote_state->pushremote_name, key,
           value);
  }

  if (!name)
    return 0;
  /* Handle remote.<name>.* variables */
  if (*name == '/') {
    warning(_("config remote shorthand cannot begin with '/': %s"),
      name);
    return 0;
  }
  remote = make_remote(remote_state, name, namelen);
  remote->origin = REMOTE_CONFIG;
  if (kvi->scope == CONFIG_SCOPE_LOCAL ||
      kvi->scope == CONFIG_SCOPE_WORKTREE)
    remote->configured_in_repo = 1;
  if (!strcmp(subkey, "mirror"))
    remote->mirror = git_config_bool(key, value);
  else if (!strcmp(subkey, "skipdefaultupdate"))
    remote->skip_default_update = git_config_bool(key, value);
  else if (!strcmp(subkey, "skipfetchall"))
    remote->skip_default_update = git_config_bool(key, value);
  else if (!strcmp(subkey, "prune"))
    remote->prune = git_config_bool(key, value);
  else if (!strcmp(subkey, "prunetags"))
    remote->prune_tags = git_config_bool(key, value);
  else if (!strcmp(subkey, "url")) {
    if (!value)
      return config_error_nonbool(key);
    add_url(remote, value);
  } else if (!strcmp(subkey, "pushurl")) {
    if (!value)
      return config_error_nonbool(key);
    add_pushurl(remote, value);
  } else if (!strcmp(subkey, "push")) {
    char *v;
    if (git_config_string(&v, key, value))
      return -1;
    refspec_append(&remote->push, v);
    free(v);
  } else if (!strcmp(subkey, "fetch")) {
    char *v;
    if (git_config_string(&v, key, value))
      return -1;
    refspec_append(&remote->fetch, v);
    free(v);
  } else if (!strcmp(subkey, "receivepack")) {
    char *v;
    if (git_config_string(&v, key, value))
      return -1;
    if (!remote->receivepack)
      remote->receivepack = v;
    else
      error(_("more than one receivepack given, using the first"));
  } else if (!strcmp(subkey, "uploadpack")) {
    char *v;
    if (git_config_string(&v, key, value))
      return -1;
    if (!remote->uploadpack)
      remote->uploadpack = v;
    else
      error(_("more than one uploadpack given, using the first"));
  } else if (!strcmp(subkey, "tagopt")) {
    if (!strcmp(value, "--no-tags"))
      remote->fetch_tags = -1;
    else if (!strcmp(value, "--tags"))
      remote->fetch_tags = 2;
  } else if (!strcmp(subkey, "proxy")) {
    FREE_AND_NULL(remote->http_proxy);
    return git_config_string(&remote->http_proxy,
           key, value);
  } else if (!strcmp(subkey, "proxyauthmethod")) {
    FREE_AND_NULL(remote->http_proxy_authmethod);
    return git_config_string(&remote->http_proxy_authmethod,
           key, value);
  } else if (!strcmp(subkey, "vcs")) {
    FREE_AND_NULL(remote->foreign_vcs);
    return git_config_string(&remote->foreign_vcs, key, value);
  } else if (!strcmp(subkey, "serveroption")) {
    return parse_transport_option(key, value,
                &remote->server_options);
  } else if (!strcmp(subkey, "followremotehead")) {
    const char *no_warn_branch;
    if (!strcmp(value, "never"))
      remote->follow_remote_head = FOLLOW_REMOTE_NEVER;
    else if (!strcmp(value, "create"))
      remote->follow_remote_head = FOLLOW_REMOTE_CREATE;
    else if (!strcmp(value, "warn")) {
      remote->follow_remote_head = FOLLOW_REMOTE_WARN;
      remote->no_warn_branch = NULL;
    } else if (skip_prefix(value, "warn-if-not-", &no_warn_branch)) {
      remote->follow_remote_head = FOLLOW_REMOTE_WARN;
      remote->no_warn_branch = no_warn_branch;
    } else if (!strcmp(value, "always")) {
      remote->follow_remote_head = FOLLOW_REMOTE_ALWAYS;
    } else {
      warning(_("unrecognized followRemoteHEAD value '%s' ignored"),
        value);
    }
  }
  return 0;
}

static void alias_all_urls(struct remote_state *remote_state)
{
  int i, j;
  for (i = 0; i < remote_state->remotes_nr; i++) {
    int add_pushurl_aliases;
    if (!remote_state->remotes[i])
      continue;
    for (j = 0; j < remote_state->remotes[i]->pushurl.nr; j++) {
      char *alias = alias_url(remote_state->remotes[i]->pushurl.v[j],
            &remote_state->rewrites);
      if (alias)
        strvec_replace(&remote_state->remotes[i]->pushurl,
                 j, alias);
      free(alias);
    }
    add_pushurl_aliases = remote_state->remotes[i]->pushurl.nr == 0;
    for (j = 0; j < remote_state->remotes[i]->url.nr; j++) {
      char *alias;
      if (add_pushurl_aliases)
        add_pushurl_alias(
          remote_state, remote_state->remotes[i],
          remote_state->remotes[i]->url.v[j]);
      alias = alias_url(remote_state->remotes[i]->url.v[j],
            &remote_state->rewrites);
      if (alias)
        strvec_replace(&remote_state->remotes[i]->url,
                 j, alias);
      free(alias);
    }
  }
}

static void read_config(struct repository *repo, int early)
{
  int flag;

  if (repo->remote_state->initialized)
    return;
  repo->remote_state->initialized = 1;

  repo->remote_state->current_branch = NULL;
  if (startup_info->have_repository && !early) {
    const char *head_ref = refs_resolve_ref_unsafe(
      get_main_ref_store(repo), "HEAD", 0, NULL, &flag);
    if (head_ref && (flag & REF_ISSYMREF) &&
        skip_prefix(head_ref, "refs/heads/", &head_ref)) {
      repo->remote_state->current_branch = make_branch(
        repo->remote_state, head_ref, strlen(head_ref));
    }
  }
  repo_config(repo, handle_config, repo->remote_state);
  alias_all_urls(repo->remote_state);
}

#ifndef WITH_BREAKING_CHANGES
static int valid_remote_nick(const char *name)
{
  if (!name[0] || is_dot_or_dotdot(name))
    return 0;

  /* remote nicknames cannot contain slashes */
  while (*name)
    if (is_dir_sep(*name++))
      return 0;
  return 1;
}
#endif /* WITH_BREAKING_CHANGES */

static const char *remotes_remote_for_branch(struct remote_state *remote_state,
               struct branch *branch,
               int *explicit)
{
  if (branch && branch->remote_name) {
    if (explicit)
      *explicit = 1;
    return branch->remote_name;
  }
  if (explicit)
    *explicit = 0;
  if (remote_state->remotes_nr == 1)
    return remote_state->remotes[0]->name;
  return "origin";
}

const char *remote_for_branch(struct branch *branch, int *explicit)
{
  read_config(the_repository, 0);
  die_on_missing_branch(the_repository, branch);

  return remotes_remote_for_branch(the_repository->remote_state, branch,
           explicit);
}

static const char *
remotes_pushremote_for_branch(struct remote_state *remote_state,
            struct branch *branch, int *explicit)
{
  if (branch && branch->pushremote_name) {
    if (explicit)
      *explicit = 1;
    return branch->pushremote_name;
  }
  if (remote_state->pushremote_name) {
    if (explicit)
      *explicit = 1;
    return remote_state->pushremote_name;
  }
  return remotes_remote_for_branch(remote_state, branch, explicit);
}

const char *pushremote_for_branch(struct branch *branch, int *explicit)
{
  read_config(the_repository, 0);
  die_on_missing_branch(the_repository, branch);

  return remotes_pushremote_for_branch(the_repository->remote_state,
               branch, explicit);
}

static struct remote *remotes_remote_get(struct repository *repo,
           const char *name);

char *remote_ref_for_branch(struct branch *branch, int for_push)
{
  read_config(the_repository, 0);
  die_on_missing_branch(the_repository, branch);

  if (branch) {
    if (!for_push) {
      if (branch->merge_nr) {
        return xstrdup(branch->merge[0]->src);
      }
    } else {
      char *dst;
      const char *remote_name = remotes_pushremote_for_branch(
          the_repository->remote_state, branch,
          NULL);
      struct remote *remote = remotes_remote_get(
        the_repository, remote_name);

      if (remote && remote->push.nr &&
          (dst = apply_refspecs(&remote->push,
              branch->refname))) {
        return dst;
      }
    }
  }
  return NULL;
}

static void validate_remote_url(struct remote *remote)
{
  int i;
  const char *value;
  struct strbuf redacted = STRBUF_INIT;
  int warn_not_die;

  if (repo_config_get_string_tmp(the_repository, "transfer.credentialsinurl", &value))
    return;

  if (!strcmp("warn", value))
    warn_not_die = 1;
  else if (!strcmp("die", value))
    warn_not_die = 0;
  else if (!strcmp("allow", value))
    return;
  else
    die(_("unrecognized value transfer.credentialsInUrl: '%s'"), value);

  for (i = 0; i < remote->url.nr; i++) {
    struct url_info url_info = { 0 };

    if (!url_normalize(remote->url.v[i], &url_info) ||
        !url_info.passwd_off)
      goto loop_cleanup;

    strbuf_reset(&redacted);
    strbuf_add(&redacted, url_info.url, url_info.passwd_off);
    strbuf_addstr(&redacted, "<redacted>");
    strbuf_addstr(&redacted,
            url_info.url + url_info.passwd_off + url_info.passwd_len);

    if (warn_not_die)
      warning(_("URL '%s' uses plaintext credentials"), redacted.buf);
    else
      die(_("URL '%s' uses plaintext credentials"), redacted.buf);

loop_cleanup:
    free(url_info.url);
  }

  strbuf_release(&redacted);
}

static struct remote *
remotes_remote_get_1(struct repository *repo, const char *name,
         const char *(*get_default)(struct remote_state *,
            struct branch *, int *))
{
  struct remote_state *remote_state = repo->remote_state;
  struct remote *ret;
  int name_given = 0;

  if (name)
    name_given = 1;
  else
    name = get_default(remote_state, remote_state->current_branch,
           &name_given);

  ret = make_remote(remote_state, name, 0);
#ifndef WITH_BREAKING_CHANGES
  if (valid_remote_nick(name) && have_git_dir()) {
    if (!valid_remote(ret))
      read_remotes_file(repo, ret);
    if (!valid_remote(ret))
      read_branches_file(repo, ret);
  }
#endif /* WITH_BREAKING_CHANGES */
  if (name_given && !valid_remote(ret))
    add_url_alias(remote_state, ret, name);
  if (!valid_remote(ret))
    return NULL;

  validate_remote_url(ret);

  return ret;
}

static inline struct remote *
remotes_remote_get(struct repository *repo, const char *name)
{
  return remotes_remote_get_1(repo, name, remotes_remote_for_branch);
}

struct remote *remote_get(const char *name)
{
  read_config(the_repository, 0);
  return remotes_remote_get(the_repository, name);
}

struct remote *remote_get_early(const char *name)
{
  read_config(the_repository, 1);
  return remotes_remote_get(the_repository, name);
}

static inline struct remote *
remotes_pushremote_get(struct repository *repo, const char *name)
{
  return remotes_remote_get_1(repo, name, remotes_pushremote_for_branch);
}

struct remote *pushremote_get(const char *name)
{
  read_config(the_repository, 0);
  return remotes_pushremote_get(the_repository, name);
}

int remote_is_configured(struct remote *remote, int in_repo)
{
  if (!remote)
    return 0;
  if (in_repo)
    return remote->configured_in_repo;
  return !!remote->origin;
}

int for_each_remote(each_remote_fn fn, void *priv)
{
  int i, result = 0;
  read_config(the_repository, 0);
  for (i = 0; i < the_repository->remote_state->remotes_nr && !result;
       i++) {
    struct remote *remote =
      the_repository->remote_state->remotes[i];
    if (!remote)
      continue;
    result = fn(remote, priv);
  }
  return result;
}

static void handle_duplicate(struct ref *ref1, struct ref *ref2)
{
  if (strcmp(ref1->name, ref2->name)) {
    if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
        ref2->fetch_head_status != FETCH_HEAD_IGNORE) {
      die(_("Cannot fetch both %s and %s to %s"),
          ref1->name, ref2->name, ref2->peer_ref->name);
    } else if (ref1->fetch_head_status != FETCH_HEAD_IGNORE &&
         ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
      warning(_("%s usually tracks %s, not %s"),
        ref2->peer_ref->name, ref2->name, ref1->name);
    } else if (ref1->fetch_head_status == FETCH_HEAD_IGNORE &&
         ref2->fetch_head_status == FETCH_HEAD_IGNORE) {
      die(_("%s tracks both %s and %s"),
          ref2->peer_ref->name, ref1->name, ref2->name);
    } else {
      /*
       * This last possibility doesn't occur because
       * FETCH_HEAD_IGNORE entries always appear at
       * the end of the list.
       */
      BUG("Internal error");
    }
  }
  free(ref2->peer_ref);
  free(ref2);
}

struct ref *ref_remove_duplicates(struct ref *ref_map)
{
  struct string_list refs = STRING_LIST_INIT_NODUP;
  struct ref *retval = NULL;
  struct ref **p = &retval;

  while (ref_map) {
    struct ref *ref = ref_map;

    ref_map = ref_map->next;
    ref->next = NULL;

    if (!ref->peer_ref) {
      *p = ref;
      p = &ref->next;
    } else {
      struct string_list_item *item =
        string_list_insert(&refs, ref->peer_ref->name);

      if (item->util) {
        /* Entry already existed */
        handle_duplicate((struct ref *)item->util, ref);
      } else {
        *p = ref;
        p = &ref->next;
        item->util = ref;
      }
    }
  }

  string_list_clear(&refs, 0);
  return retval;
}

int remote_has_url(struct remote *remote, const char *url)
{
  int i;
  for (i = 0; i < remote->url.nr; i++) {
    if (!strcmp(remote->url.v[i], url))
      return 1;
  }
  return 0;
}

struct strvec *push_url_of_remote(struct remote *remote)
{
  return remote->pushurl.nr ? &remote->pushurl : &remote->url;
}

void ref_push_report_free(struct ref_push_report *report)
{
  while (report) {
    struct ref_push_report *next = report->next;

    free(report->ref_name);
    free(report->old_oid);
    free(report->new_oid);
    free(report);

    report = next;
  }
}

int remote_find_tracking(struct remote *remote, struct refspec_item *refspec)
{
  return refspec_find_match(&remote->fetch, refspec);
}

static struct ref *alloc_ref_with_prefix(const char *prefix, size_t prefixlen,
    const char *name)
{
  size_t len = strlen(name);
  struct ref *ref = xcalloc(1, st_add4(sizeof(*ref), prefixlen, len, 1));
  memcpy(ref->name, prefix, prefixlen);
  memcpy(ref->name + prefixlen, name, len);
  return ref;
}

struct ref *alloc_ref(const char *name)
{
  return alloc_ref_with_prefix("", 0, name);
}

struct ref *copy_ref(const struct ref *ref)
{
  struct ref *cpy;
  size_t len;
  if (!ref)
    return NULL;
  len = st_add3(sizeof(struct ref), strlen(ref->name), 1);
  cpy = xmalloc(len);
  memcpy(cpy, ref, len);
  cpy->next = NULL;
  cpy->symref = xstrdup_or_null(ref->symref);
  cpy->remote_status = xstrdup_or_null(ref->remote_status);
  cpy->peer_ref = copy_ref(ref->peer_ref);
  return cpy;
}

struct ref *copy_ref_list(const struct ref *ref)
{
  struct ref *ret = NULL;
  struct ref **tail = &ret;
  while (ref) {
    *tail = copy_ref(ref);
    ref = ref->next;
    tail = &((*tail)->next);
  }
  return ret;
}

void free_one_ref(struct ref *ref)
{
  if (!ref)
    return;
  free_one_ref(ref->peer_ref);
  ref_push_report_free(ref->report);
  free(ref->remote_status);
  free(ref->tracking_ref);
  free(ref->symref);
  free(ref);
}

void free_refs(struct ref *ref)
{
  struct ref *next;
  while (ref) {
    next = ref->next;
    free_one_ref(ref);
    ref = next;
  }
}

int count_refspec_match(const char *pattern,
      struct ref *refs,
      struct ref **matched_ref)
{
  int patlen = strlen(pattern);
  struct ref *matched_weak = NULL;
  struct ref *matched = NULL;
  int weak_match = 0;
  int match = 0;

  for (weak_match = match = 0; refs; refs = refs->next) {
    char *name = refs->name;
    int namelen = strlen(name);

    if (!refname_match(pattern, name))
      continue;

    /* A match is "weak" if it is with refs outside
     * heads or tags, and did not specify the pattern
     * in full (e.g. "refs/remotes/origin/master") or at
     * least from the toplevel (e.g. "remotes/origin/master");
     * otherwise "git push $URL master" would result in
     * ambiguity between remotes/origin/master and heads/master
     * at the remote site.
     */
    if (namelen != patlen &&
        patlen != namelen - 5 &&
        !starts_with(name, "refs/heads/") &&
        !starts_with(name, "refs/tags/")) {
      /* We want to catch the case where only weak
       * matches are found and there are multiple
       * matches, and where more than one strong
       * matches are found, as ambiguous.  One
       * strong match with zero or more weak matches
       * are acceptable as a unique match.
       */
      matched_weak = refs;
      weak_match++;
    }
    else {
      matched = refs;
      match++;
    }
  }
  if (!matched) {
    if (matched_ref)
      *matched_ref = matched_weak;
    return weak_match;
  }
  else {
    if (matched_ref)
      *matched_ref = matched;
    return match;
  }
}

void tail_link_ref(struct ref *ref, struct ref ***tail)
{
  **tail = ref;
  while (ref->next)
    ref = ref->next;
  *tail = &ref->next;
}

static struct ref *alloc_delete_ref(void)
{
  struct ref *ref = alloc_ref("(delete)");
  oidclr(&ref->new_oid, the_repository->hash_algo);
  return ref;
}

static int try_explicit_object_name(const char *name,
            struct ref **match)
{
  struct object_id oid;

  if (!*name) {
    if (match)
      *match = alloc_delete_ref();
    return 0;
  }

  if (repo_get_oid(the_repository, name, &oid))
    return -1;

  if (match) {
    *match = alloc_ref(name);
    oidcpy(&(*match)->new_oid, &oid);
  }
  return 0;
}

static struct ref *make_linked_ref(const char *name, struct ref ***tail)
{
  struct ref *ret = alloc_ref(name);
  tail_link_ref(ret, tail);
  return ret;
}

static char *guess_ref(const char *name, struct ref *peer)
{
  struct strbuf buf = STRBUF_INIT;

  const char *r = refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
            peer->name,
            RESOLVE_REF_READING,
            NULL, NULL);
  if (!r)
    return NULL;

  if (starts_with(r, "refs/heads/")) {
    strbuf_addstr(&buf, "refs/heads/");
  } else if (starts_with(r, "refs/tags/")) {
    strbuf_addstr(&buf, "refs/tags/");
  } else {
    return NULL;
  }

  strbuf_addstr(&buf, name);
  return strbuf_detach(&buf, NULL);
}

static int match_explicit_lhs(struct ref *src,
            struct refspec_item *rs,
            struct ref **match,
            int *allocated_match)
{
  switch (count_refspec_match(rs->src, src, match)) {
  case 1:
    if (allocated_match)
      *allocated_match = 0;
    return 0;
  case 0:
    /* The source could be in the get_sha1() format
     * not a reference name.  :refs/other is a
     * way to delete 'other' ref at the remote end.
     */
    if (try_explicit_object_name(rs->src, match) < 0)
      return error(_("src refspec %s does not match any"), rs->src);
    if (allocated_match)
      *allocated_match = 1;
    return 0;
  default:
    return error(_("src refspec %s matches more than one"), rs->src);
  }
}

static void show_push_unqualified_ref_name_error(const char *dst_value,
             const char *matched_src_name)
{
  struct object_id oid;

  /*
   * TRANSLATORS: "matches '%s'%" is the <dst> part of "git push
   * <remote> <src>:<dst>" push, and "being pushed ('%s')" is
   * the <src>.
   */
  error(_("The destination you provided is not a full refname (i.e.,\n"
    "starting with \"refs/\"). We tried to guess what you meant by:\n"
    "\n"
    "- Looking for a ref that matches '%s' on the remote side.\n"
    "- Checking if the <src> being pushed ('%s')\n"
    "  is a ref in \"refs/{heads,tags}/\". If so we add a corresponding\n"
    "  refs/{heads,tags}/ prefix on the remote side.\n"
    "\n"
    "Neither worked, so we gave up. You must fully qualify the ref."),
        dst_value, matched_src_name);

  if (!advice_enabled(ADVICE_PUSH_UNQUALIFIED_REF_NAME))
    return;

  if (repo_get_oid(the_repository, matched_src_name, &oid))
    BUG("'%s' is not a valid object, "
        "match_explicit_lhs() should catch this!",
        matched_src_name);

  switch (odb_read_object_info(the_repository->objects, &oid, NULL)) {
  case OBJ_COMMIT:
    advise(_("The <src> part of the refspec is a commit object.\n"
       "Did you mean to create a new branch by pushing to\n"
       "'%s:refs/heads/%s'?"),
           matched_src_name, dst_value);
    break;
  case OBJ_TAG:
    advise(_("The <src> part of the refspec is a tag object.\n"
       "Did you mean to create a new tag by pushing to\n"
       "'%s:refs/tags/%s'?"),
           matched_src_name, dst_value);
    break;
  case OBJ_TREE:
    advise(_("The <src> part of the refspec is a tree object.\n"
       "Did you mean to tag a new tree by pushing to\n"
       "'%s:refs/tags/%s'?"),
           matched_src_name, dst_value);
    break;
  case OBJ_BLOB:
    advise(_("The <src> part of the refspec is a blob object.\n"
       "Did you mean to tag a new blob by pushing to\n"
       "'%s:refs/tags/%s'?"),
           matched_src_name, dst_value);
    break;
  default:
    advise(_("The <src> part of the refspec ('%s') "
       "is an object ID that doesn't exist.\n"),
           matched_src_name);
    break;
  }
}

static int match_explicit(struct ref *src, struct ref *dst,
        struct ref ***dst_tail,
        struct refspec_item *rs)
{
  struct ref *matched_src = NULL, *matched_dst = NULL;
  int allocated_src = 0, ret;

  const char *dst_value = rs->dst;
  char *dst_guess;

  if (rs->pattern || rs->matching || rs->negative) {
    ret = 0;
    goto out;
  }

  if (match_explicit_lhs(src, rs, &matched_src, &allocated_src) < 0) {
    ret = -1;
    goto out;
  }

  if (!dst_value) {
    int flag;

    dst_value = refs_resolve_ref_unsafe(get_main_ref_store(the_repository),
                matched_src->name,
                RESOLVE_REF_READING,
                NULL, &flag);
    if (!dst_value ||
        ((flag & REF_ISSYMREF) &&
         !starts_with(dst_value, "refs/heads/")))
      die(_("%s cannot be resolved to branch"),
          matched_src->name);
  }

  switch (count_refspec_match(dst_value, dst, &matched_dst)) {
  case 1:
    break;
  case 0:
    if (starts_with(dst_value, "refs/")) {
      matched_dst = make_linked_ref(dst_value, dst_tail);
    } else if (is_null_oid(&matched_src->new_oid)) {
      error(_("unable to delete '%s': remote ref does not exist"),
            dst_value);
    } else if ((dst_guess = guess_ref(dst_value, matched_src))) {
      matched_dst = make_linked_ref(dst_guess, dst_tail);
      free(dst_guess);
    } else {
      show_push_unqualified_ref_name_error(dst_value,
                   matched_src->name);
    }
    break;
  default:
    matched_dst = NULL;
    error(_("dst refspec %s matches more than one"),
          dst_value);
    break;
  }

  if (!matched_dst) {
    ret = -1;
    goto out;
  }

  if (matched_dst->peer_ref) {
    ret = error(_("dst ref %s receives from more than one src"),
          matched_dst->name);
    goto out;
  } else {
    matched_dst->peer_ref = allocated_src ?
          matched_src :
          copy_ref(matched_src);
    matched_dst->force = rs->force;
    matched_src = NULL;
  }

  ret = 0;

out:
  if (allocated_src)
    free_one_ref(matched_src);
  return ret;
}

static int match_explicit_refs(struct ref *src, struct ref *dst,
             struct ref ***dst_tail, struct refspec *rs)
{
  int i, errs;
  for (i = errs = 0; i < rs->nr; i++)
    errs += match_explicit(src, dst, dst_tail, &rs->items[i]);
  return errs;
}

static char *get_ref_match(const struct refspec *rs, const struct ref *ref,
         int send_mirror, int direction,
         const struct refspec_item **ret_pat)
{
  const struct refspec_item *pat;
  char *name;
  int i;
  int matching_refs = -1;
  for (i = 0; i < rs->nr; i++) {
    const struct refspec_item *item = &rs->items[i];

    if (item->negative)
      continue;

    if (item->matching &&
        (matching_refs == -1 || item->force)) {
      matching_refs = i;
      continue;
    }

    if (item->pattern) {
      const char *dst_side = item->dst ? item->dst : item->src;
      int match;
      if (direction == FROM_SRC)
        match = match_refname_with_pattern(item->src, ref->name, dst_side, &name);
      else
        match = match_refname_with_pattern(dst_side, ref->name, item->src, &name);
      if (match) {
        matching_refs = i;
        break;
      }
    }
  }
  if (matching_refs == -1)
    return NULL;

  pat = &rs->items[matching_refs];
  if (pat->matching) {
    /*
     * "matching refs"; traditionally we pushed everything
     * including refs outside refs/heads/ hierarchy, but
     * that does not make much sense these days.
     */
    if (!send_mirror && !starts_with(ref->name, "refs/heads/"))
      return NULL;
    name = xstrdup(ref->name);
  }
  if (ret_pat)
    *ret_pat = pat;
  return name;
}

static struct ref **tail_ref(struct ref **head)
{
  struct ref **tail = head;
  while (*tail)
    tail = &((*tail)->next);
  return tail;
}

static void add_to_tips(struct commit_stack *tips, const struct object_id *oid)
{
  struct commit *commit;

  if (is_null_oid(oid))
    return;
  commit = lookup_commit_reference_gently(the_repository, oid, 1);
  if (!commit || (commit->object.flags & TMP_MARK))
    return;
  commit->object.flags |= TMP_MARK;
  commit_stack_push(tips, commit);
}

static void add_missing_tags(struct ref *src, struct ref **dst, struct ref ***dst_tail)
{
  struct string_list dst_tag = STRING_LIST_INIT_NODUP;
  struct string_list src_tag = STRING_LIST_INIT_NODUP;
  struct string_list_item *item;
  struct ref *ref;
  struct commit_stack sent_tips = COMMIT_STACK_INIT;

  /*
   * Collect everything we know they would have at the end of
   * this push, and collect all tags they have.
   */
  for (ref = *dst; ref; ref = ref->next) {
    if (ref->peer_ref &&
        !is_null_oid(&ref->peer_ref->new_oid))
      add_to_tips(&sent_tips, &ref->peer_ref->new_oid);
    else
      add_to_tips(&sent_tips, &ref->old_oid);
    if (starts_with(ref->name, "refs/tags/"))
      string_list_append(&dst_tag, ref->name);
  }
  clear_commit_marks_many(sent_tips.nr, sent_tips.items, TMP_MARK);

  string_list_sort(&dst_tag);

  /* Collect tags they do not have. */
  for (ref = src; ref; ref = ref->next) {
    if (!starts_with(ref->name, "refs/tags/"))
      continue; /* not a tag */
    if (string_list_has_string(&dst_tag, ref->name))
      continue; /* they already have it */
    if (odb_read_object_info(the_repository->objects,
           &ref->new_oid, NULL) != OBJ_TAG)
      continue; /* be conservative */
    item = string_list_append(&src_tag, ref->name);
    item->util = ref;
  }
  string_list_clear(&dst_tag, 0);

  /*
   * At this point, src_tag lists tags that are missing from
   * dst, and sent_tips lists the tips we are pushing or those
   * that we know they already have. An element in the src_tag
   * that is an ancestor of any of the sent_tips needs to be
   * sent to the other side.
   */
  if (sent_tips.nr) {
    const int reachable_flag = 1;
    struct commit_list *found_commits;
    struct commit_stack src_commits = COMMIT_STACK_INIT;

    for_each_string_list_item(item, &src_tag) {
      struct ref *ref = item->util;
      struct commit *commit;

      if (is_null_oid(&ref->new_oid))
        continue;
      commit = lookup_commit_reference_gently(the_repository,
                &ref->new_oid,
                1);
      if (!commit)
        /* not pushing a commit, which is not an error */
        continue;

      commit_stack_push(&src_commits, commit);
    }

    found_commits = get_reachable_subset(sent_tips.items,
                 sent_tips.nr,
                 src_commits.items,
                 src_commits.nr,
                 reachable_flag);

    for_each_string_list_item(item, &src_tag) {
      struct ref *dst_ref;
      struct ref *ref = item->util;
      struct commit *commit;

      if (is_null_oid(&ref->new_oid))
        continue;
      commit = lookup_commit_reference_gently(the_repository,
                &ref->new_oid,
                1);
      if (!commit)
        /* not pushing a commit, which is not an error */
        continue;

      /*
       * Is this tag, which they do not have, reachable from
       * any of the commits we are sending?
       */
      if (!(commit->object.flags & reachable_flag))
        continue;

      /* Add it in */
      dst_ref = make_linked_ref(ref->name, dst_tail);
      oidcpy(&dst_ref->new_oid, &ref->new_oid);
      dst_ref->peer_ref = copy_ref(ref);
    }

    clear_commit_marks_many(src_commits.nr, src_commits.items,
          reachable_flag);
    commit_stack_clear(&src_commits);
    commit_list_free(found_commits);
  }

  string_list_clear(&src_tag, 0);
  commit_stack_clear(&sent_tips);
}

struct ref *find_ref_by_name(const struct ref *list, const char *name)
{
  for ( ; list; list = list->next)
    if (!strcmp(list->name, name))
      return (struct ref *)list;
  return NULL;
}

static void prepare_ref_index(struct string_list *ref_index, struct ref *ref)
{
  for ( ; ref; ref = ref->next)
    string_list_append_nodup(ref_index, ref->name)->util = ref;

  string_list_sort(ref_index);
}

/*
 * Given only the set of local refs, sanity-check the set of push
 * refspecs. We can't catch all errors that match_push_refs would,
 * but we can catch some errors early before even talking to the
 * remote side.
 */
int check_push_refs(struct ref *src, struct refspec *rs)
{
  int ret = 0;
  int i;

  for (i = 0; i < rs->nr; i++) {
    struct refspec_item *item = &rs->items[i];

    if (item->pattern || item->matching || item->negative)
      continue;

    ret |= match_explicit_lhs(src, item, NULL, NULL);
  }

  return ret;
}

/*
 * Given the set of refs the local repository has, the set of refs the
 * remote repository has, and the refspec used for push, determine
 * what remote refs we will update and with what value by setting
 * peer_ref (which object is being pushed) and force (if the push is
 * forced) in elements of "dst". The function may add new elements to
 * dst (e.g. pushing to a new branch, done in match_explicit_refs).
 */
int match_push_refs(struct ref *src, struct ref **dst,
        struct refspec *rs, int flags)
{
  int send_all = flags & MATCH_REFS_ALL;
  int send_mirror = flags & MATCH_REFS_MIRROR;
  int send_prune = flags & MATCH_REFS_PRUNE;
  int errs;
  struct ref *ref, **dst_tail = tail_ref(dst);
  struct string_list dst_ref_index = STRING_LIST_INIT_NODUP;

  /* If no refspec is provided, use the default ":" */
  if (!rs->nr)
    refspec_append(rs, ":");

  errs = match_explicit_refs(src, *dst, &dst_tail, rs);

  /* pick the remainder */
  for (ref = src; ref; ref = ref->next) {
    struct string_list_item *dst_item;
    struct ref *dst_peer;
    const struct refspec_item *pat = NULL;
    char *dst_name;

    dst_name = get_ref_match(rs, ref, send_mirror, FROM_SRC, &pat);
    if (!dst_name)
      continue;

    if (!dst_ref_index.nr)
      prepare_ref_index(&dst_ref_index, *dst);

    dst_item = string_list_lookup(&dst_ref_index, dst_name);
    dst_peer = dst_item ? dst_item->util : NULL;
    if (dst_peer) {
      if (dst_peer->peer_ref)
        /* We're already sending something to this ref. */
        goto free_name;
    } else {
      if (pat->matching && !(send_all || send_mirror))
        /*
         * Remote doesn't have it, and we have no
         * explicit pattern, and we don't have
         * --all or --mirror.
         */
        goto free_name;

      /* Create a new one and link it */
      dst_peer = make_linked_ref(dst_name, &dst_tail);
      oidcpy(&dst_peer->new_oid, &ref->new_oid);
      string_list_insert(&dst_ref_index,
        dst_peer->name)->util = dst_peer;
    }
    dst_peer->peer_ref = copy_ref(ref);
    dst_peer->force = pat->force;
  free_name:
    free(dst_name);
  }

  string_list_clear(&dst_ref_index, 0);

  if (flags & MATCH_REFS_FOLLOW_TAGS)
    add_missing_tags(src, dst, &dst_tail);

  if (send_prune) {
    struct string_list src_ref_index = STRING_LIST_INIT_NODUP;
    /* check for missing refs on the remote */
    for (ref = *dst; ref; ref = ref->next) {
      char *src_name;

      if (ref->peer_ref)
        /* We're already sending something to this ref. */
        continue;

      src_name = get_ref_match(rs, ref, send_mirror, FROM_DST, NULL);
      if (src_name) {
        if (!src_ref_index.nr)
          prepare_ref_index(&src_ref_index, src);
        if (!string_list_has_string(&src_ref_index,
              src_name))
          ref->peer_ref = alloc_delete_ref();
        free(src_name);
      }
    }
    string_list_clear(&src_ref_index, 0);
  }

  *dst = apply_negative_refspecs(*dst, rs);

  if (errs)
    return -1;
  return 0;
}

void set_ref_status_for_push(struct ref *remote_refs, int send_mirror,
           int force_update)
{
  struct ref *ref;

  for (ref = remote_refs; ref; ref = ref->next) {
    int force_ref_update = ref->force || force_update;
    int reject_reason = 0;

    if (ref->peer_ref)
      oidcpy(&ref->new_oid, &ref->peer_ref->new_oid);
    else if (!send_mirror)
      continue;

    ref->deletion = is_null_oid(&ref->new_oid);
    if (!ref->deletion &&
      oideq(&ref->old_oid, &ref->new_oid)) {
      ref->status = REF_STATUS_UPTODATE;
      continue;
    }

    /*
     * If the remote ref has moved and is now different
     * from what we expect, reject any push.
     *
     * It also is an error if the user told us to check
     * with the remote-tracking branch to find the value
     * to expect, but we did not have such a tracking
     * branch.
     *
     * If the tip of the remote-tracking ref is unreachable
     * from any reflog entry of its local ref indicating a
     * possible update since checkout; reject the push.
     */
    if (ref->expect_old_sha1) {
      if (!oideq(&ref->old_oid, &ref->old_oid_expect))
        reject_reason = REF_STATUS_REJECT_STALE;
      else if (ref->check_reachable && ref->unreachable)
        reject_reason =
          REF_STATUS_REJECT_REMOTE_UPDATED;
      else
        /*
         * If the ref isn't stale, and is reachable
         * from one of the reflog entries of
         * the local branch, force the update.
         */
        force_ref_update = 1;
    }

    /*
     * If the update isn't already rejected then check
     * the usual "must fast-forward" rules.
     *
     * Decide whether an individual refspec A:B can be
     * pushed.  The push will succeed if any of the
     * following are true:
     *
     * (1) the remote reference B does not exist
     *
     * (2) the remote reference B is being removed (i.e.,
     *     pushing :B where no source is specified)
     *
     * (3) the destination is not under refs/tags/, and
     *     if the old and new value is a commit, the new
     *     is a descendant of the old.
     *
     * (4) it is forced using the +A:B notation, or by
     *     passing the --force argument
     */

    if (!reject_reason && !ref->deletion && !is_null_oid(&ref->old_oid)) {
      if (starts_with(ref->name, "refs/tags/"))
        reject_reason = REF_STATUS_REJECT_ALREADY_EXISTS;
      else if (!odb_has_object(the_repository->objects, &ref->old_oid, HAS_OBJECT_RECHECK_PACKED))
        reject_reason = REF_STATUS_REJECT_FETCH_FIRST;
      else if (!lookup_commit_reference_gently(the_repository, &ref->old_oid, 1) ||
         !lookup_commit_reference_gently(the_repository, &ref->new_oid, 1))
        reject_reason = REF_STATUS_REJECT_NEEDS_FORCE;
      else if (!ref_newer(&ref->new_oid, &ref->old_oid))
        reject_reason = REF_STATUS_REJECT_NONFASTFORWARD;
    }

    /*
     * "--force" will defeat any rejection implemented
     * by the rules above.
     */
    if (!force_ref_update)
      ref->status = reject_reason;
    else if (reject_reason)
      ref->forced_update = 1;
  }
}

static void set_merge(struct repository *repo, struct branch *ret)
{
  struct remote *remote;
  char *ref;
  struct object_id oid;
  int i;

  if (!ret)
    return; /* no branch */
  if (ret->set_merge)
    return; /* already run */
  if (!ret->remote_name || !ret->merge_nr) {
    /*
     * no merge config; let's make sure we don't confuse callers
     * with a non-zero merge_nr but a NULL merge
     */
    merge_clear(ret);
    return;
  }
  ret->set_merge = 1;

  remote = remotes_remote_get(repo, ret->remote_name);

  for (i = 0; i < ret->merge_nr; i++) {
    if (!remote_find_tracking(remote, ret->merge[i]) ||
        strcmp(ret->remote_name, "."))
      continue;
    if (repo_dwim_ref(repo, ret->merge[i]->src,
          strlen(ret->merge[i]->src), &oid, &ref,
          0) == 1)
      ret->merge[i]->dst = ref;
    else
      ret->merge[i]->dst = xstrdup(ret->merge[i]->src);
  }
}

static struct branch *repo_branch_get(struct repository *repo, const char *name)
{
  struct branch *ret;

  read_config(repo, 0);
  if (!name || !*name || !strcmp(name, "HEAD"))
    ret = repo->remote_state->current_branch;
  else
    ret = make_branch(repo->remote_state, name,
          strlen(name));
  set_merge(repo, ret);
  return ret;
}

struct branch *branch_get(const char *name)
{
  return repo_branch_get(the_repository, name);
}

const char *repo_default_remote(struct repository *repo)
{
  struct branch *branch;

  read_config(repo, 0);
  branch = repo_branch_get(repo, "HEAD");

  return remotes_remote_for_branch(repo->remote_state, branch, NULL);
}

const char *repo_remote_from_url(struct repository *repo, const char *url)
{
  read_config(repo, 0);

  for (int i = 0; i < repo->remote_state->remotes_nr; i++) {
    struct remote *remote = repo->remote_state->remotes[i];
    if (!remote)
      continue;

    if (remote_has_url(remote, url))
      return remote->name;
  }
  return NULL;
}

int branch_has_merge_config(struct branch *branch)
{
  return branch && branch->set_merge;
}

int branch_merge_matches(struct branch *branch,
                     int i,
                     const char *refname)
{
  if (!branch || i < 0 || i >= branch->merge_nr)
    return 0;
  return refname_match(branch->merge[i]->src, refname);
}

__attribute__((format (printf,2,3)))
static char *error_buf(struct strbuf *err, const char *fmt, ...)
{
  if (err) {
    va_list ap;
    va_start(ap, fmt);
    strbuf_vaddf(err, fmt, ap);
    va_end(ap);
  }
  return NULL;
}

const char *branch_get_upstream(struct branch *branch, struct strbuf *err)
{
  if (!branch)
    return error_buf(err, _("HEAD does not point to a branch"));

  if (!branch->merge || !branch->merge[0]) {
    /*
     * no merge config; is it because the user didn't define any,
     * or because it is not a real branch, and get_branch
     * auto-vivified it?
     */
    if (!refs_ref_exists(get_main_ref_store(the_repository), branch->refname))
      return error_buf(err, _("no such branch: '%s'"),
           branch->name);
    return error_buf(err,
         _("no upstream configured for branch '%s'"),
         branch->name);
  }

  if (!branch->merge[0]->dst)
    return error_buf(err,
         _("upstream branch '%s' not stored as a remote-tracking branch"),
         branch->merge[0]->src);

  return branch->merge[0]->dst;
}

static char *tracking_for_push_dest(struct remote *remote,
            const char *refname,
            struct strbuf *err)
{
  char *ret;

  ret = apply_refspecs(&remote->fetch, refname);
  if (!ret)
    return error_buf(err,
         _("push destination '%s' on remote '%s' has no local tracking branch"),
         refname, remote->name);
  return ret;
}

static char *branch_get_push_1(struct repository *repo,
             struct branch *branch, struct strbuf *err)
{
  struct remote_state *remote_state = repo->remote_state;
  struct remote *remote;

  remote = remotes_remote_get(
    repo,
    remotes_pushremote_for_branch(remote_state, branch, NULL));
  if (!remote)
    return error_buf(err,
         _("branch '%s' has no remote for pushing"),
         branch->name);

  if (remote->push.nr) {
    char *dst;
    char *ret;

    dst = apply_refspecs(&remote->push, branch->refname);
    if (!dst)
      return error_buf(err,
           _("push refspecs for '%s' do not include '%s'"),
           remote->name, branch->name);

    ret = tracking_for_push_dest(remote, dst, err);
    free(dst);
    return ret;
  }

  if (remote->mirror)
    return tracking_for_push_dest(remote, branch->refname, err);

  switch (push_default) {
  case PUSH_DEFAULT_NOTHING:
    return error_buf(err, _("push has no destination (push.default is 'nothing')"));

  case PUSH_DEFAULT_MATCHING:
  case PUSH_DEFAULT_CURRENT:
    return tracking_for_push_dest(remote, branch->refname, err);

  case PUSH_DEFAULT_UPSTREAM:
    return xstrdup_or_null(branch_get_upstream(branch, err));

  case PUSH_DEFAULT_UNSPECIFIED:
  case PUSH_DEFAULT_SIMPLE:
    {
      const char *up;
      char *cur;

      up = branch_get_upstream(branch, err);
      if (!up)
        return NULL;
      cur = tracking_for_push_dest(remote, branch->refname, err);
      if (!cur)
        return NULL;
      if (strcmp(cur, up)) {
        free(cur);
        return error_buf(err,
             _("cannot resolve 'simple' push to a single destination"));
      }
      return cur;
    }
  }

  BUG("unhandled push situation");
}

const char *branch_get_push(struct branch *branch, struct strbuf *err)
{
  read_config(the_repository, 0);
  die_on_missing_branch(the_repository, branch);

  if (!branch)
    return error_buf(err, _("HEAD does not point to a branch"));

  if (!branch->push_tracking_ref)
    branch->push_tracking_ref = branch_get_push_1(
      the_repository, branch, err);
  return branch->push_tracking_ref;
}

static int ignore_symref_update(const char *refname, struct strbuf *scratch)
{
  return !refs_read_symbolic_ref(get_main_ref_store(the_repository), refname, scratch);
}

/*
 * Create and return a list of (struct ref) consisting of copies of
 * each remote_ref that matches refspec.  refspec must be a pattern.
 * Fill in the copies' peer_ref to describe the local tracking refs to
 * which they map.  Omit any references that would map to an existing
 * local symbolic ref.
 */
static struct ref *get_expanded_map(const struct ref *remote_refs,
            const struct refspec_item *refspec)
{
  struct strbuf scratch = STRBUF_INIT;
  const struct ref *ref;
  struct ref *ret = NULL;
  struct ref **tail = &ret;

  for (ref = remote_refs; ref; ref = ref->next) {
    char *expn_name = NULL;

    strbuf_reset(&scratch);

    if (strchr(ref->name, '^'))
      continue; /* a dereference item */
    if (match_refname_with_pattern(refspec->src, ref->name,
              refspec->dst, &expn_name) &&
        !ignore_symref_update(expn_name, &scratch)) {
      struct ref *cpy = copy_ref(ref);

      if (cpy->peer_ref)
        free_one_ref(cpy->peer_ref);
      cpy->peer_ref = alloc_ref(expn_name);
      if (refspec->force)
        cpy->peer_ref->force = 1;
      *tail = cpy;
      tail = &cpy->next;
    }
    free(expn_name);
  }

  strbuf_release(&scratch);
  return ret;
}

static const struct ref *find_ref_by_name_abbrev(const struct ref *refs, const char *name)
{
  const struct ref *ref;
  const struct ref *best_match = NULL;
  int best_score = 0;

  for (ref = refs; ref; ref = ref->next) {
    int score = refname_match(name, ref->name);

    if (best_score < score) {
      best_match = ref;
      best_score = score;
    }
  }
  return best_match;
}

struct ref *get_remote_ref(const struct ref *remote_refs, const char *name)
{
  const struct ref *ref = find_ref_by_name_abbrev(remote_refs, name);

  if (!ref)
    return NULL;

  return copy_ref(ref);
}

static struct ref *get_local_ref(const char *name)
{
  if (!name || name[0] == '\0')
    return NULL;

  if (starts_with(name, "refs/"))
    return alloc_ref(name);

  if (starts_with(name, "heads/") ||
      starts_with(name, "tags/") ||
      starts_with(name, "remotes/"))
    return alloc_ref_with_prefix("refs/", 5, name);

  return alloc_ref_with_prefix("refs/heads/", 11, name);
}

int get_fetch_map(const struct ref *remote_refs,
      const struct refspec_item *refspec,
      struct ref ***tail,
      int missing_ok)
{
  struct ref *ref_map, **rmp;

  if (refspec->negative)
    return 0;

  if (refspec->pattern) {
    ref_map = get_expanded_map(remote_refs, refspec);
  } else {
    const char *name = refspec->src[0] ? refspec->src : "HEAD";

    if (refspec->exact_sha1) {
      ref_map = alloc_ref(name);
      get_oid_hex(name, &ref_map->old_oid);
      ref_map->exact_oid = 1;
    } else {
      ref_map = get_remote_ref(remote_refs, name);
    }
    if (!missing_ok && !ref_map)
      die(_("couldn't find remote ref %s"), name);
    if (ref_map) {
      ref_map->peer_ref = get_local_ref(refspec->dst);
      if (ref_map->peer_ref && refspec->force)
        ref_map->peer_ref->force = 1;
    }
  }

  for (rmp = &ref_map; *rmp; ) {
    if ((*rmp)->peer_ref) {
      if (!starts_with((*rmp)->peer_ref->name, "refs/") ||
          check_refname_format((*rmp)->peer_ref->name, 0)) {
        struct ref *ignore = *rmp;
        error(_("* Ignoring funny ref '%s' locally"),
              (*rmp)->peer_ref->name);
        *rmp = (*rmp)->next;
        free(ignore->peer_ref);
        free(ignore);
        continue;
      }
    }
    rmp = &((*rmp)->next);
  }

  if (ref_map)
    tail_link_ref(ref_map, tail);

  return 0;
}

int resolve_remote_symref(struct ref *ref, struct ref *list)
{
  if (!ref->symref)
    return 0;
  for (; list; list = list->next)
    if (!strcmp(ref->symref, list->name)) {
      oidcpy(&ref->old_oid, &list->old_oid);
      return 0;
    }
  return 1;
}

/*
 * Compute the commit ahead/behind values for the pair branch_name, base.
 *
 * If abf is AHEAD_BEHIND_FULL, compute the full ahead/behind and return the
 * counts in *num_ours and *num_theirs.  If abf is AHEAD_BEHIND_QUICK, skip
 * the (potentially expensive) a/b computation (*num_ours and *num_theirs are
 * set to zero).
 *
 * Returns -1 if num_ours and num_theirs could not be filled in (e.g., ref
 * does not exist).  Returns 0 if the commits are identical.  Returns 1 if
 * commits are different.
 */

static int stat_branch_pair(const char *branch_name, const char *base,
           int *num_ours, int *num_theirs,
           enum ahead_behind_flags abf)
{
  struct object_id oid;
  struct commit *ours, *theirs;
  struct rev_info revs;
  struct strvec argv = STRVEC_INIT;

  /* Cannot stat if what we used to build on no longer exists */
  if (refs_read_ref(get_main_ref_store(the_repository), base, &oid))
    return -1;
  theirs = lookup_commit_reference(the_repository, &oid);
  if (!theirs)
    return -1;

  if (refs_read_ref(get_main_ref_store(the_repository), branch_name, &oid))
    return -1;
  ours = lookup_commit_reference(the_repository, &oid);
  if (!ours)
    return -1;

  *num_theirs = *num_ours = 0;

  /* are we the same? */
  if (theirs == ours)
    return 0;
  if (abf == AHEAD_BEHIND_QUICK)
    return 1;
  if (abf != AHEAD_BEHIND_FULL)
    BUG("stat_branch_pair: invalid abf '%d'", abf);

  /* Run "rev-list --left-right ours...theirs" internally... */
  strvec_push(&argv, ""); /* ignored */
  strvec_push(&argv, "--left-right");
  strvec_pushf(&argv, "%s...%s",
         oid_to_hex(&ours->object.oid),
         oid_to_hex(&theirs->object.oid));
  strvec_push(&argv, "--");

  repo_init_revisions(the_repository, &revs, NULL);
  setup_revisions_from_strvec(&argv, &revs, NULL);
  if (prepare_revision_walk(&revs))
    die(_("revision walk setup failed"));

  /* ... and count the commits on each side. */
  while (1) {
    struct commit *c = get_revision(&revs);
    if (!c)
      break;
    if (c->object.flags & SYMMETRIC_LEFT)
      (*num_ours)++;
    else
      (*num_theirs)++;
  }

  /* clear object flags smudged by the above traversal */
  clear_commit_marks(ours, ALL_REV_FLAGS);
  clear_commit_marks(theirs, ALL_REV_FLAGS);

  strvec_clear(&argv);
  release_revisions(&revs);
  return 1;
}

/*
 * Lookup the tracking branch for the given branch and if present, optionally
 * compute the commit ahead/behind values for the pair.
 *
 * If for_push is true, the tracking branch refers to the push branch,
 * otherwise it refers to the upstream branch.
 *
 * The name of the tracking branch (or NULL if it is not defined) is
 * returned via *tracking_name, if it is not itself NULL.
 *
 * If abf is AHEAD_BEHIND_FULL, compute the full ahead/behind and return the
 * counts in *num_ours and *num_theirs.  If abf is AHEAD_BEHIND_QUICK, skip
 * the (potentially expensive) a/b computation (*num_ours and *num_theirs are
 * set to zero).
 *
 * Returns -1 if num_ours and num_theirs could not be filled in (e.g., no
 * upstream defined, or ref does not exist).  Returns 0 if the commits are
 * identical.  Returns 1 if commits are different.
 */
int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs,
           const char **tracking_name, int for_push,
           enum ahead_behind_flags abf)
{
  const char *base;

  /* Cannot stat unless we are marked to build on top of somebody else. */
  base = for_push ? branch_get_push(branch, NULL) :
    branch_get_upstream(branch, NULL);
  if (tracking_name)
    *tracking_name = base;
  if (!base)
    return -1;

  return stat_branch_pair(branch->refname, base, num_ours, num_theirs, abf);
}

static char *resolve_compare_branch(struct branch *branch, const char *name)
{
  const char *resolved = NULL;

  if (!branch || !name)
    return NULL;

  if (!strcasecmp(name, "@{upstream}")) {
    resolved = branch_get_upstream(branch, NULL);
  } else if (!strcasecmp(name, "@{push}")) {
    resolved = branch_get_push(branch, NULL);
  } else {
    warning(_("ignoring value '%s' for status.compareBranches, "
        "only @{upstream} and @{push} are supported"),
      name);
    return NULL;
  }

  if (resolved)
    return xstrdup(resolved);
  return NULL;
}

static void format_branch_comparison(struct strbuf *sb,
             bool up_to_date,
             int ours, int theirs,
             const char *branch_name,
             enum ahead_behind_flags abf,
             unsigned flags)
{
  bool use_push_advice = (flags & ENABLE_ADVICE_PUSH);
  bool use_pull_advice = (flags & ENABLE_ADVICE_PULL);
  bool use_divergence_advice = (flags & ENABLE_ADVICE_DIVERGENCE);

  if (up_to_date) {
    strbuf_addf(sb,
      _("Your branch is up to date with '%s'.\n"),
      branch_name);
  } else if (abf == AHEAD_BEHIND_QUICK) {
    strbuf_addf(sb,
          _("Your branch and '%s' refer to different commits.\n"),
          branch_name);
    if (use_push_advice && advice_enabled(ADVICE_STATUS_HINTS))
      strbuf_addf(sb, _("  (use \"%s\" for details)\n"),
            "git status --ahead-behind");
  } else if (!theirs) {
    strbuf_addf(sb,
      Q_("Your branch is ahead of '%s' by %d commit.\n",
         "Your branch is ahead of '%s' by %d commits.\n",
         ours),
      branch_name, ours);
    if (use_push_advice && advice_enabled(ADVICE_STATUS_HINTS))
      strbuf_addstr(sb,
        _("  (use \"git push\" to publish your local commits)\n"));
  } else if (!ours) {
    strbuf_addf(sb,
      Q_("Your branch is behind '%s' by %d commit, "
             "and can be fast-forwarded.\n",
         "Your branch is behind '%s' by %d commits, "
             "and can be fast-forwarded.\n",
         theirs),
      branch_name, theirs);
    if (use_pull_advice && advice_enabled(ADVICE_STATUS_HINTS))
      strbuf_addstr(sb,
        _("  (use \"git pull\" to update your local branch)\n"));
  } else {
    strbuf_addf(sb,
      Q_("Your branch and '%s' have diverged,\n"
             "and have %d and %d different commit each, "
             "respectively.\n",
         "Your branch and '%s' have diverged,\n"
             "and have %d and %d different commits each, "
             "respectively.\n",
         ours + theirs),
      branch_name, ours, theirs);
    if (use_divergence_advice && advice_enabled(ADVICE_STATUS_HINTS))
      strbuf_addstr(sb,
        _("  (use \"git pull\" if you want to integrate the remote branch with yours)\n"));
  }
}

/*
 * Return true when there is anything to report, otherwise false.
 */
int format_tracking_info(struct branch *branch, struct strbuf *sb,
       enum ahead_behind_flags abf,
       int show_divergence_advice)
{
  char *compare_branches = NULL;
  struct string_list branches = STRING_LIST_INIT_DUP;
  struct strset processed_refs = STRSET_INIT;
  int reported = 0;
  size_t i;
  const char *upstream_ref;
  const char *push_ref;

  repo_config_get_string(the_repository, "status.comparebranches",
             &compare_branches);

  if (compare_branches) {
    string_list_split(&branches, compare_branches, " ", -1);
    string_list_remove_empty_items(&branches, 0);
  } else {
    string_list_append(&branches, "@{upstream}");
  }

  upstream_ref = branch_get_upstream(branch, NULL);
  push_ref = branch_get_push(branch, NULL);

  for (i = 0; i < branches.nr; i++) {
    char *full_ref;
    char *short_ref;
    int ours, theirs, cmp;
    int is_upstream, is_push;
    unsigned flags = 0;

    full_ref = resolve_compare_branch(branch,
              branches.items[i].string);
    if (!full_ref)
      continue;

    if (!strset_add(&processed_refs, full_ref)) {
      free(full_ref);
      continue;
    }

    short_ref = refs_shorten_unambiguous_ref(
      get_main_ref_store(the_repository), full_ref, 0);

    is_upstream = upstream_ref && !strcmp(full_ref, upstream_ref);
    is_push = push_ref && !strcmp(full_ref, push_ref);

    if (is_upstream && (!push_ref || !strcmp(upstream_ref, push_ref)))
      is_push = 1;

    cmp = stat_branch_pair(branch->refname, full_ref,
               &ours, &theirs, abf);

    if (cmp < 0) {
      if (is_upstream) {
        strbuf_addf(sb,
          _("Your branch is based on '%s', but the upstream is gone.\n"),
          short_ref);
        if (advice_enabled(ADVICE_STATUS_HINTS))
          strbuf_addstr(sb,
            _("  (use \"git branch --unset-upstream\" to fixup)\n"));
        reported = 1;
      }
      free(full_ref);
      free(short_ref);
      continue;
    }

    if (reported)
      strbuf_addstr(sb, "\n");

    if (is_upstream)
      flags |= ENABLE_ADVICE_PULL;
    if (is_push)
      flags |= ENABLE_ADVICE_PUSH;
    if (show_divergence_advice && is_upstream)
      flags |= ENABLE_ADVICE_DIVERGENCE;
    format_branch_comparison(sb, !cmp, ours, theirs, short_ref,
           abf, flags);
    reported = 1;

    free(full_ref);
    free(short_ref);
  }

  string_list_clear(&branches, 0);
  strset_clear(&processed_refs);
  free(compare_branches);
  return reported;
}

static int one_local_ref(const struct reference *ref, void *cb_data)
{
  struct ref ***local_tail = cb_data;
  struct ref *local_ref;

  /* we already know it starts with refs/ to get here */
  if (check_refname_format(ref->name + 5, 0))
    return 0;

  local_ref = alloc_ref(ref->name);
  oidcpy(&local_ref->new_oid, ref->oid);
  **local_tail = local_ref;
  *local_tail = &local_ref->next;
  return 0;
}

struct ref *get_local_heads(void)
{
  struct ref *local_refs = NULL, **local_tail = &local_refs;

  refs_for_each_ref(get_main_ref_store(the_repository), one_local_ref,
        &local_tail);
  return local_refs;
}

struct ref *guess_remote_head(const struct ref *head,
            const struct ref *refs,
            unsigned flags)
{
  const struct ref *r;
  struct ref *list = NULL;
  struct ref **tail = &list;

  if (!head)
    return NULL;

  /*
   * Some transports support directly peeking at
   * where HEAD points; if that is the case, then
   * we don't have to guess.
   */
  if (head->symref)
    return copy_ref(find_ref_by_name(refs, head->symref));

  /* If a remote branch exists with the default branch name, let's use it. */
  if (!(flags & REMOTE_GUESS_HEAD_ALL)) {
    char *default_branch =
      repo_default_branch_name(the_repository,
             flags & REMOTE_GUESS_HEAD_QUIET);
    char *ref = xstrfmt("refs/heads/%s", default_branch);

    r = find_ref_by_name(refs, ref);
    free(ref);
    free(default_branch);

    if (r && oideq(&r->old_oid, &head->old_oid))
      return copy_ref(r);

    /* Fall back to the hard-coded historical default */
    r = find_ref_by_name(refs, "refs/heads/master");
    if (r && oideq(&r->old_oid, &head->old_oid))
      return copy_ref(r);
  }

  /* Look for another ref that points there */
  for (r = refs; r; r = r->next) {
    if (r != head &&
        starts_with(r->name, "refs/heads/") &&
        oideq(&r->old_oid, &head->old_oid)) {
      *tail = copy_ref(r);
      tail = &((*tail)->next);
      if (!(flags & REMOTE_GUESS_HEAD_ALL))
        break;
    }
  }

  return list;
}

struct stale_heads_info {
  struct string_list *ref_names;
  struct ref **stale_refs_tail;
  struct refspec *rs;
};

static int get_stale_heads_cb(const struct reference *ref, void *cb_data)
{
  struct stale_heads_info *info = cb_data;
  struct string_list matches = STRING_LIST_INIT_DUP;
  struct refspec_item query;
  int i, stale = 1;
  memset(&query, 0, sizeof(struct refspec_item));
  query.dst = (char *)ref->name;

  refspec_find_all_matches(info->rs, &query, &matches);
  if (matches.nr == 0)
    goto clean_exit; /* No matches */

  /*
   * If we did find a suitable refspec and it's not a symref and
   * it's not in the list of refs that currently exist in that
   * remote, we consider it to be stale. In order to deal with
   * overlapping refspecs, we need to go over all of the
   * matching refs.
   */
  if (ref->flags & REF_ISSYMREF)
    goto clean_exit;

  for (i = 0; stale && i < matches.nr; i++)
    if (string_list_has_string(info->ref_names, matches.items[i].string))
      stale = 0;

  if (stale) {
    struct ref *linked_ref = make_linked_ref(ref->name, &info->stale_refs_tail);
    oidcpy(&linked_ref->new_oid, ref->oid);
  }

clean_exit:
  string_list_clear(&matches, 0);
  return 0;
}

struct ref *get_stale_heads(struct refspec *rs, struct ref *fetch_map)
{
  struct ref *ref, *stale_refs = NULL;
  struct string_list ref_names = STRING_LIST_INIT_NODUP;
  struct stale_heads_info info;

  info.ref_names = &ref_names;
  info.stale_refs_tail = &stale_refs;
  info.rs = rs;
  for (ref = fetch_map; ref; ref = ref->next)
    string_list_append(&ref_names, ref->name);
  string_list_sort(&ref_names);
  refs_for_each_ref(get_main_ref_store(the_repository),
        get_stale_heads_cb, &info);
  string_list_clear(&ref_names, 0);
  return stale_refs;
}

/*
 * Compare-and-swap
 */
void clear_cas_option(struct push_cas_option *cas)
{
  int i;

  for (i = 0; i < cas->nr; i++)
    free(cas->entry[i].refname);
  free(cas->entry);
  memset(cas, 0, sizeof(*cas));
}

static struct push_cas *add_cas_entry(struct push_cas_option *cas,
              const char *refname,
              size_t refnamelen)
{
  struct push_cas *entry;
  ALLOC_GROW(cas->entry, cas->nr + 1, cas->alloc);
  entry = &cas->entry[cas->nr++];
  memset(entry, 0, sizeof(*entry));
  entry->refname = xmemdupz(refname, refnamelen);
  return entry;
}

static int parse_push_cas_option(struct push_cas_option *cas, const char *arg, int unset)
{
  const char *colon;
  struct push_cas *entry;

  if (unset) {
    /* "--no-<option>" */
    clear_cas_option(cas);
    return 0;
  }

  if (!arg) {
    /* just "--<option>" */
    cas->use_tracking_for_rest = 1;
    return 0;
  }

  /* "--<option>=refname" or "--<option>=refname:value" */
  colon = strchrnul(arg, ':');
  entry = add_cas_entry(cas, arg, colon - arg);
  if (!*colon)
    entry->use_tracking = 1;
  else if (!colon[1])
    oidclr(&entry->expect, the_repository->hash_algo);
  else if (repo_get_oid(the_repository, colon + 1, &entry->expect))
    return error(_("cannot parse expected object name '%s'"),
           colon + 1);
  return 0;
}

int parseopt_push_cas_option(const struct option *opt, const char *arg, int unset)
{
  return parse_push_cas_option(opt->value, arg, unset);
}

int is_empty_cas(const struct push_cas_option *cas)
{
  return !cas->use_tracking_for_rest && !cas->nr;
}

/*
 * Look at remote.fetch refspec and see if we have a remote
 * tracking branch for the refname there. Fill the name of
 * the remote-tracking branch in *dst_refname, and the name
 * of the commit object at its tip in oid[].
 * If we cannot do so, return negative to signal an error.
 */
static int remote_tracking(struct remote *remote, const char *refname,
         struct object_id *oid, char **dst_refname)
{
  char *dst;

  dst = apply_refspecs(&remote->fetch, refname);
  if (!dst)
    return -1; /* no tracking ref for refname at remote */
  if (refs_read_ref(get_main_ref_store(the_repository), dst, oid)) {
    free(dst);
    return -1; /* we know what the tracking ref is but we cannot read it */
  }

  *dst_refname = dst;
  return 0;
}

struct check_and_collect_until_cb_data {
  struct commit *remote_commit;
  struct commit_stack *local_commits;
  timestamp_t remote_reflog_timestamp;
};

/* Get the timestamp of the latest entry. */
static int peek_reflog(const char *refname UNUSED,
           struct object_id *o_oid UNUSED,
           struct object_id *n_oid UNUSED,
           const char *ident UNUSED,
           timestamp_t timestamp, int tz UNUSED,
           const char *message UNUSED, void *cb_data)
{
  timestamp_t *ts = cb_data;
  *ts = timestamp;
  return 1;
}

static int check_and_collect_until(const char *refname UNUSED,
           struct object_id *o_oid UNUSED,
           struct object_id *n_oid,
           const char *ident UNUSED,
           timestamp_t timestamp, int tz UNUSED,
           const char *message UNUSED, void *cb_data)
{
  struct commit *commit;
  struct check_and_collect_until_cb_data *cb = cb_data;

  /* An entry was found. */
  if (oideq(n_oid, &cb->remote_commit->object.oid))
    return 1;

  if ((commit = lookup_commit_reference(the_repository, n_oid)))
    commit_stack_push(cb->local_commits, commit);

  /*
   * If the reflog entry timestamp is older than the remote ref's
   * latest reflog entry, there is no need to check or collect
   * entries older than this one.
   */
  if (timestamp < cb->remote_reflog_timestamp)
    return -1;

  return 0;
}

#define MERGE_BASES_BATCH_SIZE 8

/*
 * Iterate through the reflog of the local ref to check if there is an entry
 * for the given remote-tracking ref; runs until the timestamp of an entry is
 * older than latest timestamp of remote-tracking ref's reflog. Any commits
 * are that seen along the way are collected into an array to check if the
 * remote-tracking ref is reachable from any of them.
 */
static int is_reachable_in_reflog(const char *local, const struct ref *remote)
{
  timestamp_t date;
  struct commit *commit;
  struct commit **chunk;
  struct check_and_collect_until_cb_data cb;
  struct commit_stack arr = COMMIT_STACK_INIT;
  size_t size = 0;
  int ret = 0;

  commit = lookup_commit_reference(the_repository, &remote->old_oid);
  if (!commit)
    goto cleanup_return;

  /*
   * Get the timestamp from the latest entry
   * of the remote-tracking ref's reflog.
   */
  refs_for_each_reflog_ent_reverse(get_main_ref_store(the_repository),
           remote->tracking_ref, peek_reflog,
           &date);

  cb.remote_commit = commit;
  cb.local_commits = &arr;
  cb.remote_reflog_timestamp = date;
  ret = refs_for_each_reflog_ent_reverse(get_main_ref_store(the_repository),
                 local, check_and_collect_until,
                 &cb);

  /* We found an entry in the reflog. */
  if (ret > 0)
    goto cleanup_return;

  /*
   * Check if the remote commit is reachable from any
   * of the commits in the collected array, in batches.
   */
  for (chunk = arr.items; chunk < arr.items + arr.nr; chunk += size) {
    size = arr.items + arr.nr - chunk;
    if (MERGE_BASES_BATCH_SIZE < size)
      size = MERGE_BASES_BATCH_SIZE;

    if ((ret = repo_in_merge_bases_many(the_repository, commit, size, chunk, 0)))
      break;
  }

cleanup_return:
  commit_stack_clear(&arr);
  return ret;
}

/*
 * Check for reachability of a remote-tracking
 * ref in the reflog entries of its local ref.
 */
static void check_if_includes_upstream(struct ref *remote)
{
  struct ref *local = get_local_ref(remote->name);
  if (!local)
    return;

  if (is_reachable_in_reflog(local->name, remote) <= 0)
    remote->unreachable = 1;
  free_one_ref(local);
}

static void apply_cas(struct push_cas_option *cas,
          struct remote *remote,
          struct ref *ref)
{
  int i;

  /* Find an explicit --<option>=<name>[:<value>] entry */
  for (i = 0; i < cas->nr; i++) {
    struct push_cas *entry = &cas->entry[i];
    if (!refname_match(entry->refname, ref->name))
      continue;
    ref->expect_old_sha1 = 1;
    if (!entry->use_tracking)
      oidcpy(&ref->old_oid_expect, &entry->expect);
    else if (remote_tracking(remote, ref->name,
           &ref->old_oid_expect,
           &ref->tracking_ref))
      oidclr(&ref->old_oid_expect, the_repository->hash_algo);
    else
      ref->check_reachable = cas->use_force_if_includes;
    return;
  }

  /* Are we using "--<option>" to cover all? */
  if (!cas->use_tracking_for_rest)
    return;

  ref->expect_old_sha1 = 1;
  if (remote_tracking(remote, ref->name,
          &ref->old_oid_expect,
          &ref->tracking_ref))
    oidclr(&ref->old_oid_expect, the_repository->hash_algo);
  else
    ref->check_reachable = cas->use_force_if_includes;
}

void apply_push_cas(struct push_cas_option *cas,
        struct remote *remote,
        struct ref *remote_refs)
{
  struct ref *ref;
  for (ref = remote_refs; ref; ref = ref->next) {
    apply_cas(cas, remote, ref);

    /*
     * If "compare-and-swap" is in "use_tracking[_for_rest]"
     * mode, and if "--force-if-includes" was specified, run
     * the check.
     */
    if (ref->check_reachable)
      check_if_includes_upstream(ref);
  }
}

struct remote_state *remote_state_new(void)
{
  struct remote_state *r;

  CALLOC_ARRAY(r, 1);

  hashmap_init(&r->remotes_hash, remotes_hash_cmp, NULL, 0);
  hashmap_init(&r->branches_hash, branches_hash_cmp, NULL, 0);
  return r;
}

void remote_state_clear(struct remote_state *remote_state)
{
  struct hashmap_iter iter;
  struct branch *b;
  int i;

  for (i = 0; i < remote_state->remotes_nr; i++)
    remote_clear(remote_state->remotes[i]);
  FREE_AND_NULL(remote_state->remotes);
  FREE_AND_NULL(remote_state->pushremote_name);
  remote_state->remotes_alloc = 0;
  remote_state->remotes_nr = 0;

  rewrites_release(&remote_state->rewrites);
  rewrites_release(&remote_state->rewrites_push);

  hashmap_clear_and_free(&remote_state->remotes_hash, struct remote, ent);
  hashmap_for_each_entry(&remote_state->branches_hash, &iter, b, ent) {
    branch_release(b);
    free(b);
  }
  hashmap_clear(&remote_state->branches_hash);
}

/*
 * Returns 1 if it was the last chop before ':'.
 */
static int chop_last_dir(char **remoteurl, int is_relative)
{
  char *rfind = find_last_dir_sep(*remoteurl);
  if (rfind) {
    *rfind = '\0';
    return 0;
  }

  rfind = strrchr(*remoteurl, ':');
  if (rfind) {
    *rfind = '\0';
    return 1;
  }

  if (is_relative || !strcmp(".", *remoteurl))
    die(_("cannot strip one component off url '%s'"),
      *remoteurl);

  free(*remoteurl);
  *remoteurl = xstrdup(".");
  return 0;
}

char *relative_url(const char *remote_url, const char *url,
       const char *up_path)
{
  int is_relative = 0;
  int colonsep = 0;
  char *out;
  char *remoteurl;
  struct strbuf sb = STRBUF_INIT;
  size_t len;

  if (!url_is_local_not_ssh(url) || is_absolute_path(url))
    return xstrdup(url);

  len = strlen(remote_url);
  if (!len)
    BUG("invalid empty remote_url");

  remoteurl = xstrdup(remote_url);
  if (is_dir_sep(remoteurl[len-1]))
    remoteurl[len-1] = '\0';

  if (!url_is_local_not_ssh(remoteurl) || is_absolute_path(remoteurl))
    is_relative = 0;
  else {
    is_relative = 1;
    /*
     * Prepend a './' to ensure all relative
     * remoteurls start with './' or '../'
     */
    if (!starts_with_dot_slash_native(remoteurl) &&
        !starts_with_dot_dot_slash_native(remoteurl)) {
      strbuf_reset(&sb);
      strbuf_addf(&sb, "./%s", remoteurl);
      free(remoteurl);
      remoteurl = strbuf_detach(&sb, NULL);
    }
  }
  /*
   * When the url starts with '../', remove that and the
   * last directory in remoteurl.
   */
  while (*url) {
    if (starts_with_dot_dot_slash_native(url)) {
      url += 3;
      colonsep |= chop_last_dir(&remoteurl, is_relative);
    } else if (starts_with_dot_slash_native(url))
      url += 2;
    else
      break;
  }
  strbuf_reset(&sb);
  strbuf_addf(&sb, "%s%s%s", remoteurl, colonsep ? ":" : "/", url);
  if (ends_with(url, "/"))
    strbuf_setlen(&sb, sb.len - 1);
  free(remoteurl);

  if (starts_with_dot_slash_native(sb.buf))
    out = xstrdup(sb.buf + 2);
  else
    out = xstrdup(sb.buf);

  if (!up_path || !is_relative) {
    strbuf_release(&sb);
    return out;
  }

  strbuf_reset(&sb);
  strbuf_addf(&sb, "%s%s", up_path, out);
  free(out);
  return strbuf_detach(&sb, NULL);
}

int valid_remote_name(const char *name)
{
  int result;
  struct strbuf refspec = STRBUF_INIT;
  strbuf_addf(&refspec, "refs/heads/test:refs/remotes/%s/test", name);
  result = valid_fetch_refspec(refspec.buf);
  strbuf_release(&refspec);
  return result;
}

Coverage Report

Created: 2026-03-31 06:24