/src/git/builtin/am.c

Source (jump to first uncovered line)
/*
 * Builtin "git am"
 *
 * Based on git-am.sh by Junio C Hamano.
 */

#include "builtin.h"
#include "abspath.h"
#include "advice.h"
#include "config.h"
#include "editor.h"
#include "environment.h"
#include "gettext.h"
#include "hex.h"
#include "parse-options.h"
#include "dir.h"
#include "run-command.h"
#include "hook.h"
#include "quote.h"
#include "tempfile.h"
#include "lockfile.h"
#include "cache-tree.h"
#include "refs.h"
#include "commit.h"
#include "diff.h"
#include "unpack-trees.h"
#include "branch.h"
#include "object-name.h"
#include "preload-index.h"
#include "sequencer.h"
#include "revision.h"
#include "merge-recursive.h"
#include "log-tree.h"
#include "notes-utils.h"
#include "rerere.h"
#include "mailinfo.h"
#include "apply.h"
#include "string-list.h"
#include "pager.h"
#include "path.h"
#include "repository.h"
#include "pretty.h"

/**
 * Returns the length of the first line of msg.
 */
static int linelen(const char *msg)
{
  return strchrnul(msg, '\n') - msg;
}

/**
 * Returns true if `str` consists of only whitespace, false otherwise.
 */
static int str_isspace(const char *str)
{
  for (; *str; str++)
    if (!isspace(*str))
      return 0;

  return 1;
}

enum patch_format {
  PATCH_FORMAT_UNKNOWN = 0,
  PATCH_FORMAT_MBOX,
  PATCH_FORMAT_STGIT,
  PATCH_FORMAT_STGIT_SERIES,
  PATCH_FORMAT_HG,
  PATCH_FORMAT_MBOXRD
};

enum keep_type {
  KEEP_FALSE = 0,
  KEEP_TRUE,      /* pass -k flag to git-mailinfo */
  KEEP_NON_PATCH  /* pass -b flag to git-mailinfo */
};

enum scissors_type {
  SCISSORS_UNSET = -1,
  SCISSORS_FALSE = 0,  /* pass --no-scissors to git-mailinfo */
  SCISSORS_TRUE        /* pass --scissors to git-mailinfo */
};

enum signoff_type {
  SIGNOFF_FALSE = 0,
  SIGNOFF_TRUE = 1,
  SIGNOFF_EXPLICIT /* --signoff was set on the command-line */
};

enum resume_type {
  RESUME_FALSE = 0,
  RESUME_APPLY,
  RESUME_RESOLVED,
  RESUME_SKIP,
  RESUME_ABORT,
  RESUME_QUIT,
  RESUME_SHOW_PATCH_RAW,
  RESUME_SHOW_PATCH_DIFF,
  RESUME_ALLOW_EMPTY,
};

enum empty_action {
  STOP_ON_EMPTY_COMMIT = 0,  /* output errors and stop in the middle of an am session */
  DROP_EMPTY_COMMIT,         /* skip with a notice message, unless "--quiet" has been passed */
  KEEP_EMPTY_COMMIT,         /* keep recording as empty commits */
};

struct am_state {
  /* state directory path */
  char *dir;

  /* current and last patch numbers, 1-indexed */
  int cur;
  int last;

  /* commit metadata and message */
  char *author_name;
  char *author_email;
  char *author_date;
  char *msg;
  size_t msg_len;

  /* when --rebasing, records the original commit the patch came from */
  struct object_id orig_commit;

  /* number of digits in patch filename */
  int prec;

  /* various operating modes and command line options */
  int interactive;
  int no_verify;
  int threeway;
  int quiet;
  int signoff; /* enum signoff_type */
  int utf8;
  int keep; /* enum keep_type */
  int message_id;
  int scissors; /* enum scissors_type */
  int quoted_cr; /* enum quoted_cr_action */
  int empty_type; /* enum empty_action */
  struct strvec git_apply_opts;
  const char *resolvemsg;
  int committer_date_is_author_date;
  int ignore_date;
  int allow_rerere_autoupdate;
  const char *sign_commit;
  int rebasing;
};

/**
 * Initializes am_state with the default values.
 */
static void am_state_init(struct am_state *state)
{
  int gpgsign;

  memset(state, 0, sizeof(*state));

  state->dir = git_pathdup("rebase-apply");

  state->prec = 4;

  git_config_get_bool("am.threeway", &state->threeway);

  state->utf8 = 1;

  git_config_get_bool("am.messageid", &state->message_id);

  state->scissors = SCISSORS_UNSET;
  state->quoted_cr = quoted_cr_unset;

  strvec_init(&state->git_apply_opts);

  if (!git_config_get_bool("commit.gpgsign", &gpgsign))
    state->sign_commit = gpgsign ? "" : NULL;
}

/**
 * Releases memory allocated by an am_state.
 */
static void am_state_release(struct am_state *state)
{
  free(state->dir);
  free(state->author_name);
  free(state->author_email);
  free(state->author_date);
  free(state->msg);
  strvec_clear(&state->git_apply_opts);
}

static int am_option_parse_quoted_cr(const struct option *opt,
             const char *arg, int unset)
{
  BUG_ON_OPT_NEG(unset);

  if (mailinfo_parse_quoted_cr_action(arg, opt->value) != 0)
    return error(_("bad action '%s' for '%s'"), arg, "--quoted-cr");
  return 0;
}

static int am_option_parse_empty(const struct option *opt,
             const char *arg, int unset)
{
  int *opt_value = opt->value;

  BUG_ON_OPT_NEG(unset);

  if (!strcmp(arg, "stop"))
    *opt_value = STOP_ON_EMPTY_COMMIT;
  else if (!strcmp(arg, "drop"))
    *opt_value = DROP_EMPTY_COMMIT;
  else if (!strcmp(arg, "keep"))
    *opt_value = KEEP_EMPTY_COMMIT;
  else
    return error(_("invalid value for '%s': '%s'"), "--empty", arg);

  return 0;
}

/**
 * Returns path relative to the am_state directory.
 */
static inline const char *am_path(const struct am_state *state, const char *path)
{
  return mkpath("%s/%s", state->dir, path);
}

/**
 * For convenience to call write_file()
 */
static void write_state_text(const struct am_state *state,
           const char *name, const char *string)
{
  write_file(am_path(state, name), "%s", string);
}

static void write_state_count(const struct am_state *state,
            const char *name, int value)
{
  write_file(am_path(state, name), "%d", value);
}

static void write_state_bool(const struct am_state *state,
           const char *name, int value)
{
  write_state_text(state, name, value ? "t" : "f");
}

/**
 * If state->quiet is false, calls fprintf(fp, fmt, ...), and appends a newline
 * at the end.
 */
__attribute__((format (printf, 3, 4)))
static void say(const struct am_state *state, FILE *fp, const char *fmt, ...)
{
  va_list ap;

  va_start(ap, fmt);
  if (!state->quiet) {
    vfprintf(fp, fmt, ap);
    putc('\n', fp);
  }
  va_end(ap);
}

/**
 * Returns 1 if there is an am session in progress, 0 otherwise.
 */
static int am_in_progress(const struct am_state *state)
{
  struct stat st;

  if (lstat(state->dir, &st) < 0 || !S_ISDIR(st.st_mode))
    return 0;
  if (lstat(am_path(state, "last"), &st) || !S_ISREG(st.st_mode))
    return 0;
  if (lstat(am_path(state, "next"), &st) || !S_ISREG(st.st_mode))
    return 0;
  return 1;
}

/**
 * Reads the contents of `file` in the `state` directory into `sb`. Returns the
 * number of bytes read on success, -1 if the file does not exist. If `trim` is
 * set, trailing whitespace will be removed.
 */
static int read_state_file(struct strbuf *sb, const struct am_state *state,
      const char *file, int trim)
{
  strbuf_reset(sb);

  if (strbuf_read_file(sb, am_path(state, file), 0) >= 0) {
    if (trim)
      strbuf_trim(sb);

    return sb->len;
  }

  if (errno == ENOENT)
    return -1;

  die_errno(_("could not read '%s'"), am_path(state, file));
}

/**
 * Reads and parses the state directory's "author-script" file, and sets
 * state->author_name, state->author_email and state->author_date accordingly.
 * Returns 0 on success, -1 if the file could not be parsed.
 *
 * The author script is of the format:
 *
 *  GIT_AUTHOR_NAME='$author_name'
 *  GIT_AUTHOR_EMAIL='$author_email'
 *  GIT_AUTHOR_DATE='$author_date'
 *
 * where $author_name, $author_email and $author_date are quoted. We are strict
 * with our parsing, as the file was meant to be eval'd in the old git-am.sh
 * script, and thus if the file differs from what this function expects, it is
 * better to bail out than to do something that the user does not expect.
 */
static int read_am_author_script(struct am_state *state)
{
  const char *filename = am_path(state, "author-script");

  assert(!state->author_name);
  assert(!state->author_email);
  assert(!state->author_date);

  return read_author_script(filename, &state->author_name,
          &state->author_email, &state->author_date, 1);
}

/**
 * Saves state->author_name, state->author_email and state->author_date in the
 * state directory's "author-script" file.
 */
static void write_author_script(const struct am_state *state)
{
  struct strbuf sb = STRBUF_INIT;

  strbuf_addstr(&sb, "GIT_AUTHOR_NAME=");
  sq_quote_buf(&sb, state->author_name);
  strbuf_addch(&sb, '\n');

  strbuf_addstr(&sb, "GIT_AUTHOR_EMAIL=");
  sq_quote_buf(&sb, state->author_email);
  strbuf_addch(&sb, '\n');

  strbuf_addstr(&sb, "GIT_AUTHOR_DATE=");
  sq_quote_buf(&sb, state->author_date);
  strbuf_addch(&sb, '\n');

  write_state_text(state, "author-script", sb.buf);

  strbuf_release(&sb);
}

/**
 * Reads the commit message from the state directory's "final-commit" file,
 * setting state->msg to its contents and state->msg_len to the length of its
 * contents in bytes.
 *
 * Returns 0 on success, -1 if the file does not exist.
 */
static int read_commit_msg(struct am_state *state)
{
  struct strbuf sb = STRBUF_INIT;

  assert(!state->msg);

  if (read_state_file(&sb, state, "final-commit", 0) < 0) {
    strbuf_release(&sb);
    return -1;
  }

  state->msg = strbuf_detach(&sb, &state->msg_len);
  return 0;
}

/**
 * Saves state->msg in the state directory's "final-commit" file.
 */
static void write_commit_msg(const struct am_state *state)
{
  const char *filename = am_path(state, "final-commit");
  write_file_buf(filename, state->msg, state->msg_len);
}

/**
 * Loads state from disk.
 */
static void am_load(struct am_state *state)
{
  struct strbuf sb = STRBUF_INIT;

  if (read_state_file(&sb, state, "next", 1) < 0)
    BUG("state file 'next' does not exist");
  state->cur = strtol(sb.buf, NULL, 10);

  if (read_state_file(&sb, state, "last", 1) < 0)
    BUG("state file 'last' does not exist");
  state->last = strtol(sb.buf, NULL, 10);

  if (read_am_author_script(state) < 0)
    die(_("could not parse author script"));

  read_commit_msg(state);

  if (read_state_file(&sb, state, "original-commit", 1) < 0)
    oidclr(&state->orig_commit, the_repository->hash_algo);
  else if (get_oid_hex(sb.buf, &state->orig_commit) < 0)
    die(_("could not parse %s"), am_path(state, "original-commit"));

  read_state_file(&sb, state, "threeway", 1);
  state->threeway = !strcmp(sb.buf, "t");

  read_state_file(&sb, state, "quiet", 1);
  state->quiet = !strcmp(sb.buf, "t");

  read_state_file(&sb, state, "sign", 1);
  state->signoff = !strcmp(sb.buf, "t");

  read_state_file(&sb, state, "utf8", 1);
  state->utf8 = !strcmp(sb.buf, "t");

  if (file_exists(am_path(state, "rerere-autoupdate"))) {
    read_state_file(&sb, state, "rerere-autoupdate", 1);
    state->allow_rerere_autoupdate = strcmp(sb.buf, "t") ?
      RERERE_NOAUTOUPDATE : RERERE_AUTOUPDATE;
  } else {
    state->allow_rerere_autoupdate = 0;
  }

  read_state_file(&sb, state, "keep", 1);
  if (!strcmp(sb.buf, "t"))
    state->keep = KEEP_TRUE;
  else if (!strcmp(sb.buf, "b"))
    state->keep = KEEP_NON_PATCH;
  else
    state->keep = KEEP_FALSE;

  read_state_file(&sb, state, "messageid", 1);
  state->message_id = !strcmp(sb.buf, "t");

  read_state_file(&sb, state, "scissors", 1);
  if (!strcmp(sb.buf, "t"))
    state->scissors = SCISSORS_TRUE;
  else if (!strcmp(sb.buf, "f"))
    state->scissors = SCISSORS_FALSE;
  else
    state->scissors = SCISSORS_UNSET;

  read_state_file(&sb, state, "quoted-cr", 1);
  if (!*sb.buf)
    state->quoted_cr = quoted_cr_unset;
  else if (mailinfo_parse_quoted_cr_action(sb.buf, &state->quoted_cr) != 0)
    die(_("could not parse %s"), am_path(state, "quoted-cr"));

  read_state_file(&sb, state, "apply-opt", 1);
  strvec_clear(&state->git_apply_opts);
  if (sq_dequote_to_strvec(sb.buf, &state->git_apply_opts) < 0)
    die(_("could not parse %s"), am_path(state, "apply-opt"));

  state->rebasing = !!file_exists(am_path(state, "rebasing"));

  strbuf_release(&sb);
}

/**
 * Removes the am_state directory, forcefully terminating the current am
 * session.
 */
static void am_destroy(const struct am_state *state)
{
  struct strbuf sb = STRBUF_INIT;

  strbuf_addstr(&sb, state->dir);
  remove_dir_recursively(&sb, 0);
  strbuf_release(&sb);
}

/**
 * Runs applypatch-msg hook. Returns its exit code.
 */
static int run_applypatch_msg_hook(struct am_state *state)
{
  int ret = 0;

  assert(state->msg);

  if (!state->no_verify)
    ret = run_hooks_l(the_repository, "applypatch-msg",
          am_path(state, "final-commit"), NULL);

  if (!ret) {
    FREE_AND_NULL(state->msg);
    if (read_commit_msg(state) < 0)
      die(_("'%s' was deleted by the applypatch-msg hook"),
        am_path(state, "final-commit"));
  }

  return ret;
}

/**
 * Runs post-rewrite hook. Returns it exit code.
 */
static int run_post_rewrite_hook(const struct am_state *state)
{
  struct run_hooks_opt opt = RUN_HOOKS_OPT_INIT;

  strvec_push(&opt.args, "rebase");
  opt.path_to_stdin = am_path(state, "rewritten");

  return run_hooks_opt(the_repository, "post-rewrite", &opt);
}

/**
 * Reads the state directory's "rewritten" file, and copies notes from the old
 * commits listed in the file to their rewritten commits.
 *
 * Returns 0 on success, -1 on failure.
 */
static int copy_notes_for_rebase(const struct am_state *state)
{
  struct notes_rewrite_cfg *c;
  struct strbuf sb = STRBUF_INIT;
  const char *invalid_line = _("Malformed input line: '%s'.");
  const char *msg = "Notes added by 'git rebase'";
  FILE *fp;
  int ret = 0;

  assert(state->rebasing);

  c = init_copy_notes_for_rewrite("rebase");
  if (!c)
    return 0;

  fp = xfopen(am_path(state, "rewritten"), "r");

  while (!strbuf_getline_lf(&sb, fp)) {
    struct object_id from_obj, to_obj;
    const char *p;

    if (sb.len != the_hash_algo->hexsz * 2 + 1) {
      ret = error(invalid_line, sb.buf);
      goto finish;
    }

    if (parse_oid_hex(sb.buf, &from_obj, &p)) {
      ret = error(invalid_line, sb.buf);
      goto finish;
    }

    if (*p != ' ') {
      ret = error(invalid_line, sb.buf);
      goto finish;
    }

    if (get_oid_hex(p + 1, &to_obj)) {
      ret = error(invalid_line, sb.buf);
      goto finish;
    }

    if (copy_note_for_rewrite(c, &from_obj, &to_obj))
      ret = error(_("Failed to copy notes from '%s' to '%s'"),
          oid_to_hex(&from_obj), oid_to_hex(&to_obj));
  }

finish:
  finish_copy_notes_for_rewrite(the_repository, c, msg);
  fclose(fp);
  strbuf_release(&sb);
  return ret;
}

/**
 * Determines if the file looks like a piece of RFC2822 mail by grabbing all
 * non-indented lines and checking if they look like they begin with valid
 * header field names.
 *
 * Returns 1 if the file looks like a piece of mail, 0 otherwise.
 */
static int is_mail(FILE *fp)
{
  const char *header_regex = "^[!-9;-~]+:";
  struct strbuf sb = STRBUF_INIT;
  regex_t regex;
  int ret = 1;

  if (fseek(fp, 0L, SEEK_SET))
    die_errno(_("fseek failed"));

  if (regcomp(&regex, header_regex, REG_NOSUB | REG_EXTENDED))
    die("invalid pattern: %s", header_regex);

  while (!strbuf_getline(&sb, fp)) {
    if (!sb.len)
      break; /* End of header */

    /* Ignore indented folded lines */
    if (*sb.buf == '\t' || *sb.buf == ' ')
      continue;

    /* It's a header if it matches header_regex */
    if (regexec(&regex, sb.buf, 0, NULL, 0)) {
      ret = 0;
      goto done;
    }
  }

done:
  regfree(&regex);
  strbuf_release(&sb);
  return ret;
}

/**
 * Attempts to detect the patch_format of the patches contained in `paths`,
 * returning the PATCH_FORMAT_* enum value. Returns PATCH_FORMAT_UNKNOWN if
 * detection fails.
 */
static int detect_patch_format(const char **paths)
{
  enum patch_format ret = PATCH_FORMAT_UNKNOWN;
  struct strbuf l1 = STRBUF_INIT;
  struct strbuf l2 = STRBUF_INIT;
  struct strbuf l3 = STRBUF_INIT;
  FILE *fp;

  /*
   * We default to mbox format if input is from stdin and for directories
   */
  if (!*paths || !strcmp(*paths, "-") || is_directory(*paths))
    return PATCH_FORMAT_MBOX;

  /*
   * Otherwise, check the first few lines of the first patch, starting
   * from the first non-blank line, to try to detect its format.
   */

  fp = xfopen(*paths, "r");

  while (!strbuf_getline(&l1, fp)) {
    if (l1.len)
      break;
  }

  if (starts_with(l1.buf, "From ") || starts_with(l1.buf, "From: ")) {
    ret = PATCH_FORMAT_MBOX;
    goto done;
  }

  if (starts_with(l1.buf, "# This series applies on GIT commit")) {
    ret = PATCH_FORMAT_STGIT_SERIES;
    goto done;
  }

  if (!strcmp(l1.buf, "# HG changeset patch")) {
    ret = PATCH_FORMAT_HG;
    goto done;
  }

  strbuf_getline(&l2, fp);
  strbuf_getline(&l3, fp);

  /*
   * If the second line is empty and the third is a From, Author or Date
   * entry, this is likely an StGit patch.
   */
  if (l1.len && !l2.len &&
    (starts_with(l3.buf, "From:") ||
     starts_with(l3.buf, "Author:") ||
     starts_with(l3.buf, "Date:"))) {
    ret = PATCH_FORMAT_STGIT;
    goto done;
  }

  if (l1.len && is_mail(fp)) {
    ret = PATCH_FORMAT_MBOX;
    goto done;
  }

done:
  fclose(fp);
  strbuf_release(&l1);
  strbuf_release(&l2);
  strbuf_release(&l3);
  return ret;
}

/**
 * Splits out individual email patches from `paths`, where each path is either
 * a mbox file or a Maildir. Returns 0 on success, -1 on failure.
 */
static int split_mail_mbox(struct am_state *state, const char **paths,
        int keep_cr, int mboxrd)
{
  struct child_process cp = CHILD_PROCESS_INIT;
  struct strbuf last = STRBUF_INIT;
  int ret;

  cp.git_cmd = 1;
  strvec_push(&cp.args, "mailsplit");
  strvec_pushf(&cp.args, "-d%d", state->prec);
  strvec_pushf(&cp.args, "-o%s", state->dir);
  strvec_push(&cp.args, "-b");
  if (keep_cr)
    strvec_push(&cp.args, "--keep-cr");
  if (mboxrd)
    strvec_push(&cp.args, "--mboxrd");
  strvec_push(&cp.args, "--");
  strvec_pushv(&cp.args, paths);

  ret = capture_command(&cp, &last, 8);
  if (ret)
    goto exit;

  state->cur = 1;
  state->last = strtol(last.buf, NULL, 10);

exit:
  strbuf_release(&last);
  return ret ? -1 : 0;
}

/**
 * Callback signature for split_mail_conv(). The foreign patch should be
 * read from `in`, and the converted patch (in RFC2822 mail format) should be
 * written to `out`. Return 0 on success, or -1 on failure.
 */
typedef int (*mail_conv_fn)(FILE *out, FILE *in, int keep_cr);

/**
 * Calls `fn` for each file in `paths` to convert the foreign patch to the
 * RFC2822 mail format suitable for parsing with git-mailinfo.
 *
 * Returns 0 on success, -1 on failure.
 */
static int split_mail_conv(mail_conv_fn fn, struct am_state *state,
      const char **paths, int keep_cr)
{
  static const char *stdin_only[] = {"-", NULL};
  int i;

  if (!*paths)
    paths = stdin_only;

  for (i = 0; *paths; paths++, i++) {
    FILE *in, *out;
    const char *mail;
    int ret;

    if (!strcmp(*paths, "-"))
      in = stdin;
    else
      in = fopen(*paths, "r");

    if (!in)
      return error_errno(_("could not open '%s' for reading"),
             *paths);

    mail = mkpath("%s/%0*d", state->dir, state->prec, i + 1);

    out = fopen(mail, "w");
    if (!out) {
      if (in != stdin)
        fclose(in);
      return error_errno(_("could not open '%s' for writing"),
             mail);
    }

    ret = fn(out, in, keep_cr);

    fclose(out);
    if (in != stdin)
      fclose(in);

    if (ret)
      return error(_("could not parse patch '%s'"), *paths);
  }

  state->cur = 1;
  state->last = i;
  return 0;
}

/**
 * A split_mail_conv() callback that converts an StGit patch to an RFC2822
 * message suitable for parsing with git-mailinfo.
 */
static int stgit_patch_to_mail(FILE *out, FILE *in, int keep_cr UNUSED)
{
  struct strbuf sb = STRBUF_INIT;
  int subject_printed = 0;

  while (!strbuf_getline_lf(&sb, in)) {
    const char *str;

    if (str_isspace(sb.buf))
      continue;
    else if (skip_prefix(sb.buf, "Author:", &str))
      fprintf(out, "From:%s\n", str);
    else if (starts_with(sb.buf, "From") || starts_with(sb.buf, "Date"))
      fprintf(out, "%s\n", sb.buf);
    else if (!subject_printed) {
      fprintf(out, "Subject: %s\n", sb.buf);
      subject_printed = 1;
    } else {
      fprintf(out, "\n%s\n", sb.buf);
      break;
    }
  }

  strbuf_reset(&sb);
  while (strbuf_fread(&sb, 8192, in) > 0) {
    fwrite(sb.buf, 1, sb.len, out);
    strbuf_reset(&sb);
  }

  strbuf_release(&sb);
  return 0;
}

/**
 * This function only supports a single StGit series file in `paths`.
 *
 * Given an StGit series file, converts the StGit patches in the series into
 * RFC2822 messages suitable for parsing with git-mailinfo, and queues them in
 * the state directory.
 *
 * Returns 0 on success, -1 on failure.
 */
static int split_mail_stgit_series(struct am_state *state, const char **paths,
          int keep_cr)
{
  const char *series_dir;
  char *series_dir_buf;
  FILE *fp;
  struct strvec patches = STRVEC_INIT;
  struct strbuf sb = STRBUF_INIT;
  int ret;

  if (!paths[0] || paths[1])
    return error(_("Only one StGIT patch series can be applied at once"));

  series_dir_buf = xstrdup(*paths);
  series_dir = dirname(series_dir_buf);

  fp = fopen(*paths, "r");
  if (!fp)
    return error_errno(_("could not open '%s' for reading"), *paths);

  while (!strbuf_getline_lf(&sb, fp)) {
    if (*sb.buf == '#')
      continue; /* skip comment lines */

    strvec_push(&patches, mkpath("%s/%s", series_dir, sb.buf));
  }

  fclose(fp);
  strbuf_release(&sb);
  free(series_dir_buf);

  ret = split_mail_conv(stgit_patch_to_mail, state, patches.v, keep_cr);

  strvec_clear(&patches);
  return ret;
}

/**
 * A split_patches_conv() callback that converts a mercurial patch to a RFC2822
 * message suitable for parsing with git-mailinfo.
 */
static int hg_patch_to_mail(FILE *out, FILE *in, int keep_cr UNUSED)
{
  struct strbuf sb = STRBUF_INIT;
  int rc = 0;

  while (!strbuf_getline_lf(&sb, in)) {
    const char *str;

    if (skip_prefix(sb.buf, "# User ", &str))
      fprintf(out, "From: %s\n", str);
    else if (skip_prefix(sb.buf, "# Date ", &str)) {
      timestamp_t timestamp;
      long tz, tz2;
      char *end;

      errno = 0;
      timestamp = parse_timestamp(str, &end, 10);
      if (errno) {
        rc = error(_("invalid timestamp"));
        goto exit;
      }

      if (!skip_prefix(end, " ", &str)) {
        rc = error(_("invalid Date line"));
        goto exit;
      }

      errno = 0;
      tz = strtol(str, &end, 10);
      if (errno) {
        rc = error(_("invalid timezone offset"));
        goto exit;
      }

      if (*end) {
        rc = error(_("invalid Date line"));
        goto exit;
      }

      /*
       * mercurial's timezone is in seconds west of UTC,
       * however git's timezone is in hours + minutes east of
       * UTC. Convert it.
       */
      tz2 = labs(tz) / 3600 * 100 + labs(tz) % 3600 / 60;
      if (tz > 0)
        tz2 = -tz2;

      fprintf(out, "Date: %s\n", show_date(timestamp, tz2, DATE_MODE(RFC2822)));
    } else if (starts_with(sb.buf, "# ")) {
      continue;
    } else {
      fprintf(out, "\n%s\n", sb.buf);
      break;
    }
  }

  strbuf_reset(&sb);
  while (strbuf_fread(&sb, 8192, in) > 0) {
    fwrite(sb.buf, 1, sb.len, out);
    strbuf_reset(&sb);
  }
exit:
  strbuf_release(&sb);
  return rc;
}

/**
 * Splits a list of files/directories into individual email patches. Each path
 * in `paths` must be a file/directory that is formatted according to
 * `patch_format`.
 *
 * Once split out, the individual email patches will be stored in the state
 * directory, with each patch's filename being its index, padded to state->prec
 * digits.
 *
 * state->cur will be set to the index of the first mail, and state->last will
 * be set to the index of the last mail.
 *
 * Set keep_cr to 0 to convert all lines ending with \r\n to end with \n, 1
 * to disable this behavior, -1 to use the default configured setting.
 *
 * Returns 0 on success, -1 on failure.
 */
static int split_mail(struct am_state *state, enum patch_format patch_format,
      const char **paths, int keep_cr)
{
  if (keep_cr < 0) {
    keep_cr = 0;
    git_config_get_bool("am.keepcr", &keep_cr);
  }

  switch (patch_format) {
  case PATCH_FORMAT_MBOX:
    return split_mail_mbox(state, paths, keep_cr, 0);
  case PATCH_FORMAT_STGIT:
    return split_mail_conv(stgit_patch_to_mail, state, paths, keep_cr);
  case PATCH_FORMAT_STGIT_SERIES:
    return split_mail_stgit_series(state, paths, keep_cr);
  case PATCH_FORMAT_HG:
    return split_mail_conv(hg_patch_to_mail, state, paths, keep_cr);
  case PATCH_FORMAT_MBOXRD:
    return split_mail_mbox(state, paths, keep_cr, 1);
  default:
    BUG("invalid patch_format");
  }
  return -1;
}

/**
 * Setup a new am session for applying patches
 */
static void am_setup(struct am_state *state, enum patch_format patch_format,
      const char **paths, int keep_cr)
{
  struct object_id curr_head;
  const char *str;
  struct strbuf sb = STRBUF_INIT;

  if (!patch_format)
    patch_format = detect_patch_format(paths);

  if (!patch_format) {
    fprintf_ln(stderr, _("Patch format detection failed."));
    exit(128);
  }

  if (mkdir(state->dir, 0777) < 0 && errno != EEXIST)
    die_errno(_("failed to create directory '%s'"), state->dir);
  refs_delete_ref(get_main_ref_store(the_repository), NULL,
      "REBASE_HEAD", NULL, REF_NO_DEREF);

  if (split_mail(state, patch_format, paths, keep_cr) < 0) {
    am_destroy(state);
    die(_("Failed to split patches."));
  }

  if (state->rebasing)
    state->threeway = 1;

  write_state_bool(state, "threeway", state->threeway);
  write_state_bool(state, "quiet", state->quiet);
  write_state_bool(state, "sign", state->signoff);
  write_state_bool(state, "utf8", state->utf8);

  if (state->allow_rerere_autoupdate)
    write_state_bool(state, "rerere-autoupdate",
       state->allow_rerere_autoupdate == RERERE_AUTOUPDATE);

  switch (state->keep) {
  case KEEP_FALSE:
    str = "f";
    break;
  case KEEP_TRUE:
    str = "t";
    break;
  case KEEP_NON_PATCH:
    str = "b";
    break;
  default:
    BUG("invalid value for state->keep");
  }

  write_state_text(state, "keep", str);
  write_state_bool(state, "messageid", state->message_id);

  switch (state->scissors) {
  case SCISSORS_UNSET:
    str = "";
    break;
  case SCISSORS_FALSE:
    str = "f";
    break;
  case SCISSORS_TRUE:
    str = "t";
    break;
  default:
    BUG("invalid value for state->scissors");
  }
  write_state_text(state, "scissors", str);

  switch (state->quoted_cr) {
  case quoted_cr_unset:
    str = "";
    break;
  case quoted_cr_nowarn:
    str = "nowarn";
    break;
  case quoted_cr_warn:
    str = "warn";
    break;
  case quoted_cr_strip:
    str = "strip";
    break;
  default:
    BUG("invalid value for state->quoted_cr");
  }
  write_state_text(state, "quoted-cr", str);

  sq_quote_argv(&sb, state->git_apply_opts.v);
  write_state_text(state, "apply-opt", sb.buf);

  if (state->rebasing)
    write_state_text(state, "rebasing", "");
  else
    write_state_text(state, "applying", "");

  if (!repo_get_oid(the_repository, "HEAD", &curr_head)) {
    write_state_text(state, "abort-safety", oid_to_hex(&curr_head));
    if (!state->rebasing)
      refs_update_ref(get_main_ref_store(the_repository),
          "am", "ORIG_HEAD", &curr_head, NULL,
          0,
          UPDATE_REFS_DIE_ON_ERR);
  } else {
    write_state_text(state, "abort-safety", "");
    if (!state->rebasing)
      refs_delete_ref(get_main_ref_store(the_repository),
          NULL, "ORIG_HEAD", NULL, 0);
  }

  /*
   * NOTE: Since the "next" and "last" files determine if an am_state
   * session is in progress, they should be written last.
   */

  write_state_count(state, "next", state->cur);
  write_state_count(state, "last", state->last);

  strbuf_release(&sb);
}

/**
 * Increments the patch pointer, and cleans am_state for the application of the
 * next patch.
 */
static void am_next(struct am_state *state)
{
  struct object_id head;

  FREE_AND_NULL(state->author_name);
  FREE_AND_NULL(state->author_email);
  FREE_AND_NULL(state->author_date);
  FREE_AND_NULL(state->msg);
  state->msg_len = 0;

  unlink(am_path(state, "author-script"));
  unlink(am_path(state, "final-commit"));

  oidclr(&state->orig_commit, the_repository->hash_algo);
  unlink(am_path(state, "original-commit"));
  refs_delete_ref(get_main_ref_store(the_repository), NULL,
      "REBASE_HEAD", NULL, REF_NO_DEREF);

  if (!repo_get_oid(the_repository, "HEAD", &head))
    write_state_text(state, "abort-safety", oid_to_hex(&head));
  else
    write_state_text(state, "abort-safety", "");

  state->cur++;
  write_state_count(state, "next", state->cur);
}

/**
 * Returns the filename of the current patch email.
 */
static const char *msgnum(const struct am_state *state)
{
  static struct strbuf sb = STRBUF_INIT;

  strbuf_reset(&sb);
  strbuf_addf(&sb, "%0*d", state->prec, state->cur);

  return sb.buf;
}

/**
 * Dies with a user-friendly message on how to proceed after resolving the
 * problem. This message can be overridden with state->resolvemsg.
 */
static void NORETURN die_user_resolve(const struct am_state *state)
{
  if (state->resolvemsg) {
    advise_if_enabled(ADVICE_MERGE_CONFLICT, "%s", state->resolvemsg);
  } else {
    const char *cmdline = state->interactive ? "git am -i" : "git am";
    struct strbuf sb = STRBUF_INIT;

    strbuf_addf(&sb, _("When you have resolved this problem, run \"%s --continue\".\n"), cmdline);
    strbuf_addf(&sb, _("If you prefer to skip this patch, run \"%s --skip\" instead.\n"), cmdline);

    if (advice_enabled(ADVICE_AM_WORK_DIR) &&
        is_empty_or_missing_file(am_path(state, "patch")) &&
        !repo_index_has_changes(the_repository, NULL, NULL))
      strbuf_addf(&sb, _("To record the empty patch as an empty commit, run \"%s --allow-empty\".\n"), cmdline);

    strbuf_addf(&sb, _("To restore the original branch and stop patching, run \"%s --abort\"."), cmdline);

    advise_if_enabled(ADVICE_MERGE_CONFLICT, "%s", sb.buf);
    strbuf_release(&sb);
  }

  exit(128);
}

/**
 * Appends signoff to the "msg" field of the am_state.
 */
static void am_append_signoff(struct am_state *state)
{
  struct strbuf sb = STRBUF_INIT;

  strbuf_attach(&sb, state->msg, state->msg_len, state->msg_len);
  append_signoff(&sb, 0, 0);
  state->msg = strbuf_detach(&sb, &state->msg_len);
}

/**
 * Parses `mail` using git-mailinfo, extracting its patch and authorship info.
 * state->msg will be set to the patch message. state->author_name,
 * state->author_email and state->author_date will be set to the patch author's
 * name, email and date respectively. The patch body will be written to the
 * state directory's "patch" file.
 *
 * Returns 1 if the patch should be skipped, 0 otherwise.
 */
static int parse_mail(struct am_state *state, const char *mail)
{
  FILE *fp;
  struct strbuf sb = STRBUF_INIT;
  struct strbuf msg = STRBUF_INIT;
  struct strbuf author_name = STRBUF_INIT;
  struct strbuf author_date = STRBUF_INIT;
  struct strbuf author_email = STRBUF_INIT;
  int ret = 0;
  struct mailinfo mi;

  setup_mailinfo(&mi);

  if (state->utf8)
    mi.metainfo_charset = get_commit_output_encoding();
  else
    mi.metainfo_charset = NULL;

  switch (state->keep) {
  case KEEP_FALSE:
    break;
  case KEEP_TRUE:
    mi.keep_subject = 1;
    break;
  case KEEP_NON_PATCH:
    mi.keep_non_patch_brackets_in_subject = 1;
    break;
  default:
    BUG("invalid value for state->keep");
  }

  if (state->message_id)
    mi.add_message_id = 1;

  switch (state->scissors) {
  case SCISSORS_UNSET:
    break;
  case SCISSORS_FALSE:
    mi.use_scissors = 0;
    break;
  case SCISSORS_TRUE:
    mi.use_scissors = 1;
    break;
  default:
    BUG("invalid value for state->scissors");
  }

  switch (state->quoted_cr) {
  case quoted_cr_unset:
    break;
  case quoted_cr_nowarn:
  case quoted_cr_warn:
  case quoted_cr_strip:
    mi.quoted_cr = state->quoted_cr;
    break;
  default:
    BUG("invalid value for state->quoted_cr");
  }

  mi.input = xfopen(mail, "r");
  mi.output = xfopen(am_path(state, "info"), "w");
  if (mailinfo(&mi, am_path(state, "msg"), am_path(state, "patch")))
    die("could not parse patch");

  fclose(mi.input);
  fclose(mi.output);

  if (mi.format_flowed)
    warning(_("Patch sent with format=flowed; "
        "space at the end of lines might be lost."));

  /* Extract message and author information */
  fp = xfopen(am_path(state, "info"), "r");
  while (!strbuf_getline_lf(&sb, fp)) {
    const char *x;

    if (skip_prefix(sb.buf, "Subject: ", &x)) {
      if (msg.len)
        strbuf_addch(&msg, '\n');
      strbuf_addstr(&msg, x);
    } else if (skip_prefix(sb.buf, "Author: ", &x))
      strbuf_addstr(&author_name, x);
    else if (skip_prefix(sb.buf, "Email: ", &x))
      strbuf_addstr(&author_email, x);
    else if (skip_prefix(sb.buf, "Date: ", &x))
      strbuf_addstr(&author_date, x);
  }
  fclose(fp);

  /* Skip pine's internal folder data */
  if (!strcmp(author_name.buf, "Mail System Internal Data")) {
    ret = 1;
    goto finish;
  }

  strbuf_addstr(&msg, "\n\n");
  strbuf_addbuf(&msg, &mi.log_message);
  strbuf_stripspace(&msg, NULL);

  assert(!state->author_name);
  state->author_name = strbuf_detach(&author_name, NULL);

  assert(!state->author_email);
  state->author_email = strbuf_detach(&author_email, NULL);

  assert(!state->author_date);
  state->author_date = strbuf_detach(&author_date, NULL);

  assert(!state->msg);
  state->msg = strbuf_detach(&msg, &state->msg_len);

finish:
  strbuf_release(&msg);
  strbuf_release(&author_date);
  strbuf_release(&author_email);
  strbuf_release(&author_name);
  strbuf_release(&sb);
  clear_mailinfo(&mi);
  return ret;
}

/**
 * Sets commit_id to the commit hash where the mail was generated from.
 * Returns 0 on success, -1 on failure.
 */
static int get_mail_commit_oid(struct object_id *commit_id, const char *mail)
{
  struct strbuf sb = STRBUF_INIT;
  FILE *fp = xfopen(mail, "r");
  const char *x;
  int ret = 0;

  if (strbuf_getline_lf(&sb, fp) ||
      !skip_prefix(sb.buf, "From ", &x) ||
      get_oid_hex(x, commit_id) < 0)
    ret = -1;

  strbuf_release(&sb);
  fclose(fp);
  return ret;
}

/**
 * Sets state->msg, state->author_name, state->author_email, state->author_date
 * to the commit's respective info.
 */
static void get_commit_info(struct am_state *state, struct commit *commit)
{
  const char *buffer, *ident_line, *msg;
  size_t ident_len;
  struct ident_split id;

  buffer = repo_logmsg_reencode(the_repository, commit, NULL,
              get_commit_output_encoding());

  ident_line = find_commit_header(buffer, "author", &ident_len);
  if (!ident_line)
    die(_("missing author line in commit %s"),
          oid_to_hex(&commit->object.oid));
  if (split_ident_line(&id, ident_line, ident_len) < 0)
    die(_("invalid ident line: %.*s"), (int)ident_len, ident_line);

  assert(!state->author_name);
  if (id.name_begin)
    state->author_name =
      xmemdupz(id.name_begin, id.name_end - id.name_begin);
  else
    state->author_name = xstrdup("");

  assert(!state->author_email);
  if (id.mail_begin)
    state->author_email =
      xmemdupz(id.mail_begin, id.mail_end - id.mail_begin);
  else
    state->author_email = xstrdup("");

  assert(!state->author_date);
  state->author_date = xstrdup(show_ident_date(&id, DATE_MODE(NORMAL)));

  assert(!state->msg);
  msg = strstr(buffer, "\n\n");
  if (!msg)
    die(_("unable to parse commit %s"), oid_to_hex(&commit->object.oid));
  state->msg = xstrdup(msg + 2);
  state->msg_len = strlen(state->msg);
  repo_unuse_commit_buffer(the_repository, commit, buffer);
}

/**
 * Writes `commit` as a patch to the state directory's "patch" file.
 */
static void write_commit_patch(const struct am_state *state, struct commit *commit)
{
  struct rev_info rev_info;
  FILE *fp;

  fp = xfopen(am_path(state, "patch"), "w");
  repo_init_revisions(the_repository, &rev_info, NULL);
  rev_info.diff = 1;
  rev_info.abbrev = 0;
  rev_info.disable_stdin = 1;
  rev_info.show_root_diff = 1;
  rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
  rev_info.no_commit_id = 1;
  rev_info.diffopt.flags.binary = 1;
  rev_info.diffopt.flags.full_index = 1;
  rev_info.diffopt.use_color = 0;
  rev_info.diffopt.file = fp;
  rev_info.diffopt.close_file = 1;
  add_pending_object(&rev_info, &commit->object, "");
  diff_setup_done(&rev_info.diffopt);
  log_tree_commit(&rev_info, commit);
  release_revisions(&rev_info);
}

/**
 * Writes the diff of the index against HEAD as a patch to the state
 * directory's "patch" file.
 */
static void write_index_patch(const struct am_state *state)
{
  struct tree *tree;
  struct object_id head;
  struct rev_info rev_info;
  FILE *fp;

  if (!repo_get_oid(the_repository, "HEAD", &head)) {
    struct commit *commit = lookup_commit_or_die(&head, "HEAD");
    tree = repo_get_commit_tree(the_repository, commit);
  } else
    tree = lookup_tree(the_repository,
           the_repository->hash_algo->empty_tree);

  fp = xfopen(am_path(state, "patch"), "w");
  repo_init_revisions(the_repository, &rev_info, NULL);
  rev_info.diff = 1;
  rev_info.disable_stdin = 1;
  rev_info.no_commit_id = 1;
  rev_info.diffopt.output_format = DIFF_FORMAT_PATCH;
  rev_info.diffopt.use_color = 0;
  rev_info.diffopt.file = fp;
  rev_info.diffopt.close_file = 1;
  add_pending_object(&rev_info, &tree->object, "");
  diff_setup_done(&rev_info.diffopt);
  run_diff_index(&rev_info, DIFF_INDEX_CACHED);
  release_revisions(&rev_info);
}

/**
 * Like parse_mail(), but parses the mail by looking up its commit ID
 * directly. This is used in --rebasing mode to bypass git-mailinfo's munging
 * of patches.
 *
 * state->orig_commit will be set to the original commit ID.
 *
 * Will always return 0 as the patch should never be skipped.
 */
static int parse_mail_rebase(struct am_state *state, const char *mail)
{
  struct commit *commit;
  struct object_id commit_oid;

  if (get_mail_commit_oid(&commit_oid, mail) < 0)
    die(_("could not parse %s"), mail);

  commit = lookup_commit_or_die(&commit_oid, mail);

  get_commit_info(state, commit);

  write_commit_patch(state, commit);

  oidcpy(&state->orig_commit, &commit_oid);
  write_state_text(state, "original-commit", oid_to_hex(&commit_oid));
  refs_update_ref(get_main_ref_store(the_repository), "am",
      "REBASE_HEAD", &commit_oid,
      NULL, REF_NO_DEREF, UPDATE_REFS_DIE_ON_ERR);

  return 0;
}

/**
 * Applies current patch with git-apply. Returns 0 on success, -1 otherwise. If
 * `index_file` is not NULL, the patch will be applied to that index.
 */
static int run_apply(const struct am_state *state, const char *index_file)
{
  struct strvec apply_paths = STRVEC_INIT;
  struct strvec apply_opts = STRVEC_INIT;
  struct apply_state apply_state;
  int res, opts_left;
  int force_apply = 0;
  int options = 0;
  const char **apply_argv;

  if (init_apply_state(&apply_state, the_repository, NULL))
    BUG("init_apply_state() failed");

  strvec_push(&apply_opts, "apply");
  strvec_pushv(&apply_opts, state->git_apply_opts.v);

  /*
   * Build a copy that apply_parse_options() can rearrange.
   * apply_opts.v keeps referencing the allocated strings for
   * strvec_clear() to release.
   */
  DUP_ARRAY(apply_argv, apply_opts.v, apply_opts.nr);

  opts_left = apply_parse_options(apply_opts.nr, apply_argv,
          &apply_state, &force_apply, &options,
          NULL);

  if (opts_left != 0)
    die("unknown option passed through to git apply");

  if (index_file) {
    apply_state.index_file = index_file;
    apply_state.cached = 1;
  } else
    apply_state.check_index = 1;

  /*
   * If we are allowed to fall back on 3-way merge, don't give false
   * errors during the initial attempt.
   */
  if (state->threeway && !index_file)
    apply_state.apply_verbosity = verbosity_silent;

  if (check_apply_state(&apply_state, force_apply))
    BUG("check_apply_state() failed");

  strvec_push(&apply_paths, am_path(state, "patch"));

  res = apply_all_patches(&apply_state, apply_paths.nr, apply_paths.v, options);

  strvec_clear(&apply_paths);
  strvec_clear(&apply_opts);
  clear_apply_state(&apply_state);
  free(apply_argv);

  if (res)
    return res;

  if (index_file) {
    /* Reload index as apply_all_patches() will have modified it. */
    discard_index(the_repository->index);
    read_index_from(the_repository->index, index_file, get_git_dir());
  }

  return 0;
}

/**
 * Builds an index that contains just the blobs needed for a 3way merge.
 */
static int build_fake_ancestor(const struct am_state *state, const char *index_file)
{
  struct child_process cp = CHILD_PROCESS_INIT;

  cp.git_cmd = 1;
  strvec_push(&cp.args, "apply");
  strvec_pushv(&cp.args, state->git_apply_opts.v);
  strvec_pushf(&cp.args, "--build-fake-ancestor=%s", index_file);
  strvec_push(&cp.args, am_path(state, "patch"));

  if (run_command(&cp))
    return -1;

  return 0;
}

/**
 * Attempt a threeway merge, using index_path as the temporary index.
 */
static int fall_back_threeway(const struct am_state *state, const char *index_path)
{
  struct object_id their_tree, our_tree;
  struct object_id bases[1] = { 0 };
  struct merge_options o;
  struct commit *result;
  char *their_tree_name;

  if (repo_get_oid(the_repository, "HEAD", &our_tree) < 0)
    oidcpy(&our_tree, the_hash_algo->empty_tree);

  if (build_fake_ancestor(state, index_path))
    return error("could not build fake ancestor");

  discard_index(the_repository->index);
  read_index_from(the_repository->index, index_path, get_git_dir());

  if (write_index_as_tree(&bases[0], the_repository->index, index_path, 0, NULL))
    return error(_("Repository lacks necessary blobs to fall back on 3-way merge."));

  say(state, stdout, _("Using index info to reconstruct a base tree..."));

  if (!state->quiet) {
    /*
     * List paths that needed 3-way fallback, so that the user can
     * review them with extra care to spot mismerges.
     */
    struct rev_info rev_info;

    repo_init_revisions(the_repository, &rev_info, NULL);
    rev_info.diffopt.output_format = DIFF_FORMAT_NAME_STATUS;
    rev_info.diffopt.filter |= diff_filter_bit('A');
    rev_info.diffopt.filter |= diff_filter_bit('M');
    add_pending_oid(&rev_info, "HEAD", &our_tree, 0);
    diff_setup_done(&rev_info.diffopt);
    run_diff_index(&rev_info, DIFF_INDEX_CACHED);
    release_revisions(&rev_info);
  }

  if (run_apply(state, index_path))
    return error(_("Did you hand edit your patch?\n"
        "It does not apply to blobs recorded in its index."));

  if (write_index_as_tree(&their_tree, the_repository->index, index_path, 0, NULL))
    return error("could not write tree");

  say(state, stdout, _("Falling back to patching base and 3-way merge..."));

  discard_index(the_repository->index);
  repo_read_index(the_repository);

  /*
   * This is not so wrong. Depending on which base we picked, orig_tree
   * may be wildly different from ours, but their_tree has the same set of
   * wildly different changes in parts the patch did not touch, so
   * recursive ends up canceling them, saying that we reverted all those
   * changes.
   */

  init_ui_merge_options(&o, the_repository);

  o.branch1 = "HEAD";
  their_tree_name = xstrfmt("%.*s", linelen(state->msg), state->msg);
  o.branch2 = their_tree_name;
  o.detect_directory_renames = MERGE_DIRECTORY_RENAMES_NONE;

  if (state->quiet)
    o.verbosity = 0;

  if (merge_recursive_generic(&o, &our_tree, &their_tree, 1, bases, &result)) {
    repo_rerere(the_repository, state->allow_rerere_autoupdate);
    free(their_tree_name);
    return error(_("Failed to merge in the changes."));
  }

  free(their_tree_name);
  return 0;
}

/**
 * Commits the current index with state->msg as the commit message and
 * state->author_name, state->author_email and state->author_date as the author
 * information.
 */
static void do_commit(const struct am_state *state)
{
  struct object_id tree, parent, commit;
  const struct object_id *old_oid;
  struct commit_list *parents = NULL;
  const char *reflog_msg, *author, *committer = NULL;
  struct strbuf sb = STRBUF_INIT;

  if (!state->no_verify && run_hooks(the_repository, "pre-applypatch"))
    exit(1);

  if (write_index_as_tree(&tree, the_repository->index, get_index_file(), 0, NULL))
    die(_("git write-tree failed to write a tree"));

  if (!repo_get_oid_commit(the_repository, "HEAD", &parent)) {
    old_oid = &parent;
    commit_list_insert(lookup_commit(the_repository, &parent),
           &parents);
  } else {
    old_oid = NULL;
    say(state, stderr, _("applying to an empty history"));
  }

  author = fmt_ident(state->author_name, state->author_email,
    WANT_AUTHOR_IDENT,
      state->ignore_date ? NULL : state->author_date,
      IDENT_STRICT);

  if (state->committer_date_is_author_date)
    committer = fmt_ident(getenv("GIT_COMMITTER_NAME"),
              getenv("GIT_COMMITTER_EMAIL"),
              WANT_COMMITTER_IDENT,
              state->ignore_date ? NULL
               : state->author_date,
              IDENT_STRICT);

  if (commit_tree_extended(state->msg, state->msg_len, &tree, parents,
         &commit, author, committer, state->sign_commit,
         NULL))
    die(_("failed to write commit object"));

  reflog_msg = getenv("GIT_REFLOG_ACTION");
  if (!reflog_msg)
    reflog_msg = "am";

  strbuf_addf(&sb, "%s: %.*s", reflog_msg, linelen(state->msg),
      state->msg);

  refs_update_ref(get_main_ref_store(the_repository), sb.buf, "HEAD",
      &commit, old_oid, 0,
      UPDATE_REFS_DIE_ON_ERR);

  if (state->rebasing) {
    FILE *fp = xfopen(am_path(state, "rewritten"), "a");

    assert(!is_null_oid(&state->orig_commit));
    fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
    fprintf(fp, "%s\n", oid_to_hex(&commit));
    fclose(fp);
  }

  run_hooks(the_repository, "post-applypatch");

  free_commit_list(parents);
  strbuf_release(&sb);
}

/**
 * Validates the am_state for resuming -- the "msg" and authorship fields must
 * be filled up.
 */
static void validate_resume_state(const struct am_state *state)
{
  if (!state->msg)
    die(_("cannot resume: %s does not exist."),
      am_path(state, "final-commit"));

  if (!state->author_name || !state->author_email || !state->author_date)
    die(_("cannot resume: %s does not exist."),
      am_path(state, "author-script"));
}

/**
 * Interactively prompt the user on whether the current patch should be
 * applied.
 *
 * Returns 0 if the user chooses to apply the patch, 1 if the user chooses to
 * skip it.
 */
static int do_interactive(struct am_state *state)
{
  assert(state->msg);

  for (;;) {
    char reply[64];

    puts(_("Commit Body is:"));
    puts("--------------------------");
    printf("%s", state->msg);
    puts("--------------------------");

    /*
     * TRANSLATORS: Make sure to include [y], [n], [e], [v] and [a]
     * in your translation. The program will only accept English
     * input at this point.
     */
    printf(_("Apply? [y]es/[n]o/[e]dit/[v]iew patch/[a]ccept all: "));
    if (!fgets(reply, sizeof(reply), stdin))
      die("unable to read from stdin; aborting");

    if (*reply == 'y' || *reply == 'Y') {
      return 0;
    } else if (*reply == 'a' || *reply == 'A') {
      state->interactive = 0;
      return 0;
    } else if (*reply == 'n' || *reply == 'N') {
      return 1;
    } else if (*reply == 'e' || *reply == 'E') {
      struct strbuf msg = STRBUF_INIT;

      if (!launch_editor(am_path(state, "final-commit"), &msg, NULL)) {
        free(state->msg);
        state->msg = strbuf_detach(&msg, &state->msg_len);
      }
      strbuf_release(&msg);
    } else if (*reply == 'v' || *reply == 'V') {
      const char *pager = git_pager(1);
      struct child_process cp = CHILD_PROCESS_INIT;

      if (!pager)
        pager = "cat";
      prepare_pager_args(&cp, pager);
      strvec_push(&cp.args, am_path(state, "patch"));
      run_command(&cp);
    }
  }
}

/**
 * Applies all queued mail.
 *
 * If `resume` is true, we are "resuming". The "msg" and authorship fields, as
 * well as the state directory's "patch" file is used as-is for applying the
 * patch and committing it.
 */
static void am_run(struct am_state *state, int resume)
{
  struct strbuf sb = STRBUF_INIT;

  unlink(am_path(state, "dirtyindex"));

  if (repo_refresh_and_write_index(the_repository, REFRESH_QUIET, 0, 0,
           NULL, NULL, NULL) < 0)
    die(_("unable to write index file"));

  if (repo_index_has_changes(the_repository, NULL, &sb)) {
    write_state_bool(state, "dirtyindex", 1);
    die(_("Dirty index: cannot apply patches (dirty: %s)"), sb.buf);
  }

  strbuf_release(&sb);

  while (state->cur <= state->last) {
    const char *mail = am_path(state, msgnum(state));
    int apply_status;
    int to_keep;

    reset_ident_date();

    if (!file_exists(mail))
      goto next;

    if (resume) {
      validate_resume_state(state);
    } else {
      int skip;

      if (state->rebasing)
        skip = parse_mail_rebase(state, mail);
      else
        skip = parse_mail(state, mail);

      if (skip)
        goto next; /* mail should be skipped */

      if (state->signoff)
        am_append_signoff(state);

      write_author_script(state);
      write_commit_msg(state);
    }

    if (state->interactive && do_interactive(state))
      goto next;

    to_keep = 0;
    if (is_empty_or_missing_file(am_path(state, "patch"))) {
      switch (state->empty_type) {
      case DROP_EMPTY_COMMIT:
        say(state, stdout, _("Skipping: %.*s"), linelen(state->msg), state->msg);
        goto next;
        break;
      case KEEP_EMPTY_COMMIT:
        to_keep = 1;
        say(state, stdout, _("Creating an empty commit: %.*s"),
          linelen(state->msg), state->msg);
        break;
      case STOP_ON_EMPTY_COMMIT:
        printf_ln(_("Patch is empty."));
        die_user_resolve(state);
        break;
      }
    }

    if (run_applypatch_msg_hook(state))
      exit(1);
    if (to_keep)
      goto commit;

    say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);

    apply_status = run_apply(state, NULL);

    if (apply_status && state->threeway) {
      struct strbuf sb = STRBUF_INIT;

      strbuf_addstr(&sb, am_path(state, "patch-merge-index"));
      apply_status = fall_back_threeway(state, sb.buf);
      strbuf_release(&sb);

      /*
       * Applying the patch to an earlier tree and merging
       * the result may have produced the same tree as ours.
       */
      if (!apply_status &&
          !repo_index_has_changes(the_repository, NULL, NULL)) {
        say(state, stdout, _("No changes -- Patch already applied."));
        goto next;
      }
    }

    if (apply_status) {
      printf_ln(_("Patch failed at %s %.*s"), msgnum(state),
        linelen(state->msg), state->msg);

      if (advice_enabled(ADVICE_AM_WORK_DIR))
        advise(_("Use 'git am --show-current-patch=diff' to see the failed patch"));

      die_user_resolve(state);
    }

commit:
    do_commit(state);

next:
    am_next(state);

    if (resume)
      am_load(state);
    resume = 0;
  }

  if (!is_empty_or_missing_file(am_path(state, "rewritten"))) {
    assert(state->rebasing);
    copy_notes_for_rebase(state);
    run_post_rewrite_hook(state);
  }

  /*
   * In rebasing mode, it's up to the caller to take care of
   * housekeeping.
   */
  if (!state->rebasing) {
    am_destroy(state);
    run_auto_maintenance(state->quiet);
  }
}

/**
 * Resume the current am session after patch application failure. The user did
 * all the hard work, and we do not have to do any patch application. Just
 * trust and commit what the user has in the index and working tree. If `allow_empty`
 * is true, commit as an empty commit when index has not changed and lacking a patch.
 */
static void am_resolve(struct am_state *state, int allow_empty)
{
  validate_resume_state(state);

  say(state, stdout, _("Applying: %.*s"), linelen(state->msg), state->msg);

  if (!repo_index_has_changes(the_repository, NULL, NULL)) {
    if (allow_empty && is_empty_or_missing_file(am_path(state, "patch"))) {
      printf_ln(_("No changes - recorded it as an empty commit."));
    } else {
      printf_ln(_("No changes - did you forget to use 'git add'?\n"
            "If there is nothing left to stage, chances are that something else\n"
            "already introduced the same changes; you might want to skip this patch."));
      die_user_resolve(state);
    }
  }

  if (unmerged_index(the_repository->index)) {
    printf_ln(_("You still have unmerged paths in your index.\n"
      "You should 'git add' each file with resolved conflicts to mark them as such.\n"
      "You might run `git rm` on a file to accept \"deleted by them\" for it."));
    die_user_resolve(state);
  }

  if (state->interactive) {
    write_index_patch(state);
    if (do_interactive(state))
      goto next;
  }

  repo_rerere(the_repository, 0);

  do_commit(state);

next:
  am_next(state);
  am_load(state);
  am_run(state, 0);
}

/**
 * Performs a checkout fast-forward from `head` to `remote`. If `reset` is
 * true, any unmerged entries will be discarded. Returns 0 on success, -1 on
 * failure.
 */
static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
{
  struct lock_file lock_file = LOCK_INIT;
  struct unpack_trees_options opts;
  struct tree_desc t[2];

  if (parse_tree(head) || parse_tree(remote))
    return -1;

  repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);

  refresh_index(the_repository->index, REFRESH_QUIET, NULL, NULL, NULL);

  memset(&opts, 0, sizeof(opts));
  opts.head_idx = 1;
  opts.src_index = the_repository->index;
  opts.dst_index = the_repository->index;
  opts.update = 1;
  opts.merge = 1;
  opts.reset = reset ? UNPACK_RESET_PROTECT_UNTRACKED : 0;
  opts.preserve_ignored = 0; /* FIXME: !overwrite_ignore */
  opts.fn = twoway_merge;
  init_tree_desc(&t[0], &head->object.oid, head->buffer, head->size);
  init_tree_desc(&t[1], &remote->object.oid, remote->buffer, remote->size);

  if (unpack_trees(2, t, &opts)) {
    rollback_lock_file(&lock_file);
    return -1;
  }

  if (write_locked_index(the_repository->index, &lock_file, COMMIT_LOCK))
    die(_("unable to write new index file"));

  return 0;
}

/**
 * Merges a tree into the index. The index's stat info will take precedence
 * over the merged tree's. Returns 0 on success, -1 on failure.
 */
static int merge_tree(struct tree *tree)
{
  struct lock_file lock_file = LOCK_INIT;
  struct unpack_trees_options opts;
  struct tree_desc t[1];

  if (parse_tree(tree))
    return -1;

  repo_hold_locked_index(the_repository, &lock_file, LOCK_DIE_ON_ERROR);

  memset(&opts, 0, sizeof(opts));
  opts.head_idx = 1;
  opts.src_index = the_repository->index;
  opts.dst_index = the_repository->index;
  opts.merge = 1;
  opts.fn = oneway_merge;
  init_tree_desc(&t[0], &tree->object.oid, tree->buffer, tree->size);

  if (unpack_trees(1, t, &opts)) {
    rollback_lock_file(&lock_file);
    return -1;
  }

  if (write_locked_index(the_repository->index, &lock_file, COMMIT_LOCK))
    die(_("unable to write new index file"));

  return 0;
}

/**
 * Clean the index without touching entries that are not modified between
 * `head` and `remote`.
 */
static int clean_index(const struct object_id *head, const struct object_id *remote)
{
  struct tree *head_tree, *remote_tree, *index_tree;
  struct object_id index;

  head_tree = parse_tree_indirect(head);
  if (!head_tree)
    return error(_("Could not parse object '%s'."), oid_to_hex(head));

  remote_tree = parse_tree_indirect(remote);
  if (!remote_tree)
    return error(_("Could not parse object '%s'."), oid_to_hex(remote));

  repo_read_index_unmerged(the_repository);

  if (fast_forward_to(head_tree, head_tree, 1))
    return -1;

  if (write_index_as_tree(&index, the_repository->index, get_index_file(), 0, NULL))
    return -1;

  index_tree = parse_tree_indirect(&index);
  if (!index_tree)
    return error(_("Could not parse object '%s'."), oid_to_hex(&index));

  if (fast_forward_to(index_tree, remote_tree, 0))
    return -1;

  if (merge_tree(remote_tree))
    return -1;

  remove_branch_state(the_repository, 0);

  return 0;
}

/**
 * Resets rerere's merge resolution metadata.
 */
static void am_rerere_clear(void)
{
  struct string_list merge_rr = STRING_LIST_INIT_DUP;
  rerere_clear(the_repository, &merge_rr);
  string_list_clear(&merge_rr, 1);
}

/**
 * Resume the current am session by skipping the current patch.
 */
static void am_skip(struct am_state *state)
{
  struct object_id head;

  am_rerere_clear();

  if (repo_get_oid(the_repository, "HEAD", &head))
    oidcpy(&head, the_hash_algo->empty_tree);

  if (clean_index(&head, &head))
    die(_("failed to clean index"));

  if (state->rebasing) {
    FILE *fp = xfopen(am_path(state, "rewritten"), "a");

    assert(!is_null_oid(&state->orig_commit));
    fprintf(fp, "%s ", oid_to_hex(&state->orig_commit));
    fprintf(fp, "%s\n", oid_to_hex(&head));
    fclose(fp);
  }

  am_next(state);
  am_load(state);
  am_run(state, 0);
}

/**
 * Returns true if it is safe to reset HEAD to the ORIG_HEAD, false otherwise.
 *
 * It is not safe to reset HEAD when:
 * 1. git-am previously failed because the index was dirty.
 * 2. HEAD has moved since git-am previously failed.
 */
static int safe_to_abort(const struct am_state *state)
{
  struct strbuf sb = STRBUF_INIT;
  struct object_id abort_safety, head;

  if (file_exists(am_path(state, "dirtyindex")))
    return 0;

  if (read_state_file(&sb, state, "abort-safety", 1) > 0) {
    if (get_oid_hex(sb.buf, &abort_safety))
      die(_("could not parse %s"), am_path(state, "abort-safety"));
  } else
    oidclr(&abort_safety, the_repository->hash_algo);
  strbuf_release(&sb);

  if (repo_get_oid(the_repository, "HEAD", &head))
    oidclr(&head, the_repository->hash_algo);

  if (oideq(&head, &abort_safety))
    return 1;

  warning(_("You seem to have moved HEAD since the last 'am' failure.\n"
    "Not rewinding to ORIG_HEAD"));

  return 0;
}

/**
 * Aborts the current am session if it is safe to do so.
 */
static void am_abort(struct am_state *state)
{
  struct object_id curr_head, orig_head;
  int has_curr_head, has_orig_head;
  char *curr_branch;

  if (!safe_to_abort(state)) {
    am_destroy(state);
    return;
  }

  am_rerere_clear();

  curr_branch = refs_resolve_refdup(get_main_ref_store(the_repository),
            "HEAD", 0, &curr_head, NULL);
  has_curr_head = curr_branch && !is_null_oid(&curr_head);
  if (!has_curr_head)
    oidcpy(&curr_head, the_hash_algo->empty_tree);

  has_orig_head = !repo_get_oid(the_repository, "ORIG_HEAD", &orig_head);
  if (!has_orig_head)
    oidcpy(&orig_head, the_hash_algo->empty_tree);

  if (clean_index(&curr_head, &orig_head))
    die(_("failed to clean index"));

  if (has_orig_head)
    refs_update_ref(get_main_ref_store(the_repository),
        "am --abort", "HEAD", &orig_head,
        has_curr_head ? &curr_head : NULL, 0,
        UPDATE_REFS_DIE_ON_ERR);
  else if (curr_branch)
    refs_delete_ref(get_main_ref_store(the_repository), NULL,
        curr_branch, NULL, REF_NO_DEREF);

  free(curr_branch);
  am_destroy(state);
}

static int show_patch(struct am_state *state, enum resume_type resume_mode)
{
  struct strbuf sb = STRBUF_INIT;
  const char *patch_path;
  int len;

  if (!is_null_oid(&state->orig_commit)) {
    struct child_process cmd = CHILD_PROCESS_INIT;

    strvec_pushl(&cmd.args, "show", oid_to_hex(&state->orig_commit),
           "--", NULL);
    cmd.git_cmd = 1;
    return run_command(&cmd);
  }

  switch (resume_mode) {
  case RESUME_SHOW_PATCH_RAW:
    patch_path = am_path(state, msgnum(state));
    break;
  case RESUME_SHOW_PATCH_DIFF:
    patch_path = am_path(state, "patch");
    break;
  default:
    BUG("invalid mode for --show-current-patch");
  }

  len = strbuf_read_file(&sb, patch_path, 0);
  if (len < 0)
    die_errno(_("failed to read '%s'"), patch_path);

  setup_pager();
  write_in_full(1, sb.buf, sb.len);
  strbuf_release(&sb);
  return 0;
}

/**
 * parse_options() callback that validates and sets opt->value to the
 * PATCH_FORMAT_* enum value corresponding to `arg`.
 */
static int parse_opt_patchformat(const struct option *opt, const char *arg, int unset)
{
  int *opt_value = opt->value;

  if (unset)
    *opt_value = PATCH_FORMAT_UNKNOWN;
  else if (!strcmp(arg, "mbox"))
    *opt_value = PATCH_FORMAT_MBOX;
  else if (!strcmp(arg, "stgit"))
    *opt_value = PATCH_FORMAT_STGIT;
  else if (!strcmp(arg, "stgit-series"))
    *opt_value = PATCH_FORMAT_STGIT_SERIES;
  else if (!strcmp(arg, "hg"))
    *opt_value = PATCH_FORMAT_HG;
  else if (!strcmp(arg, "mboxrd"))
    *opt_value = PATCH_FORMAT_MBOXRD;
  /*
   * Please update $__git_patchformat in git-completion.bash
   * when you add new options
   */
  else
    return error(_("invalid value for '%s': '%s'"),
           "--patch-format", arg);
  return 0;
}

static int parse_opt_show_current_patch(const struct option *opt, const char *arg, int unset)
{
  int *opt_value = opt->value;

  BUG_ON_OPT_NEG(unset);

  if (!arg)
    *opt_value = opt->defval;
  else if (!strcmp(arg, "raw"))
    *opt_value = RESUME_SHOW_PATCH_RAW;
  else if (!strcmp(arg, "diff"))
    *opt_value = RESUME_SHOW_PATCH_DIFF;
  /*
   * Please update $__git_showcurrentpatch in git-completion.bash
   * when you add new options
   */
  else
    return error(_("invalid value for '%s': '%s'"),
           "--show-current-patch", arg);
  return 0;
}

int cmd_am(int argc, const char **argv, const char *prefix)
{
  struct am_state state;
  int binary = -1;
  int keep_cr = -1;
  int patch_format = PATCH_FORMAT_UNKNOWN;
  enum resume_type resume_mode = RESUME_FALSE;
  int in_progress;
  int ret = 0;

  const char * const usage[] = {
    N_("git am [<options>] [(<mbox> | <Maildir>)...]"),
    N_("git am [<options>] (--continue | --skip | --abort)"),
    NULL
  };

  struct option options[] = {
    OPT_BOOL('i', "interactive", &state.interactive,
      N_("run interactively")),
    OPT_BOOL('n', "no-verify", &state.no_verify,
      N_("bypass pre-applypatch and applypatch-msg hooks")),
    OPT_HIDDEN_BOOL('b', "binary", &binary,
      N_("historical option -- no-op")),
    OPT_BOOL('3', "3way", &state.threeway,
      N_("allow fall back on 3way merging if needed")),
    OPT__QUIET(&state.quiet, N_("be quiet")),
    OPT_SET_INT('s', "signoff", &state.signoff,
      N_("add a Signed-off-by trailer to the commit message"),
      SIGNOFF_EXPLICIT),
    OPT_BOOL('u', "utf8", &state.utf8,
      N_("recode into utf8 (default)")),
    OPT_SET_INT('k', "keep", &state.keep,
      N_("pass -k flag to git-mailinfo"), KEEP_TRUE),
    OPT_SET_INT(0, "keep-non-patch", &state.keep,
      N_("pass -b flag to git-mailinfo"), KEEP_NON_PATCH),
    OPT_BOOL('m', "message-id", &state.message_id,
      N_("pass -m flag to git-mailinfo")),
    OPT_SET_INT(0, "keep-cr", &keep_cr,
          N_("pass --keep-cr flag to git-mailsplit for mbox format"),
          1),
    OPT_BOOL('c', "scissors", &state.scissors,
      N_("strip everything before a scissors line")),
    OPT_CALLBACK_F(0, "quoted-cr", &state.quoted_cr, N_("action"),
             N_("pass it through git-mailinfo"),
             PARSE_OPT_NONEG, am_option_parse_quoted_cr),
    OPT_PASSTHRU_ARGV(0, "whitespace", &state.git_apply_opts, N_("action"),
      N_("pass it through git-apply"),
      0),
    OPT_PASSTHRU_ARGV(0, "ignore-space-change", &state.git_apply_opts, NULL,
      N_("pass it through git-apply"),
      PARSE_OPT_NOARG),
    OPT_PASSTHRU_ARGV(0, "ignore-whitespace", &state.git_apply_opts, NULL,
      N_("pass it through git-apply"),
      PARSE_OPT_NOARG),
    OPT_PASSTHRU_ARGV(0, "directory", &state.git_apply_opts, N_("root"),
      N_("pass it through git-apply"),
      0),
    OPT_PASSTHRU_ARGV(0, "exclude", &state.git_apply_opts, N_("path"),
      N_("pass it through git-apply"),
      0),
    OPT_PASSTHRU_ARGV(0, "include", &state.git_apply_opts, N_("path"),
      N_("pass it through git-apply"),
      0),
    OPT_PASSTHRU_ARGV('C', NULL, &state.git_apply_opts, N_("n"),
      N_("pass it through git-apply"),
      0),
    OPT_PASSTHRU_ARGV('p', NULL, &state.git_apply_opts, N_("num"),
      N_("pass it through git-apply"),
      0),
    OPT_CALLBACK(0, "patch-format", &patch_format, N_("format"),
      N_("format the patch(es) are in"),
      parse_opt_patchformat),
    OPT_PASSTHRU_ARGV(0, "reject", &state.git_apply_opts, NULL,
      N_("pass it through git-apply"),
      PARSE_OPT_NOARG),
    OPT_STRING(0, "resolvemsg", &state.resolvemsg, NULL,
      N_("override error message when patch failure occurs")),
    OPT_CMDMODE(0, "continue", &resume_mode,
      N_("continue applying patches after resolving a conflict"),
      RESUME_RESOLVED),
    OPT_CMDMODE('r', "resolved", &resume_mode,
      N_("synonyms for --continue"),
      RESUME_RESOLVED),
    OPT_CMDMODE(0, "skip", &resume_mode,
      N_("skip the current patch"),
      RESUME_SKIP),
    OPT_CMDMODE(0, "abort", &resume_mode,
      N_("restore the original branch and abort the patching operation"),
      RESUME_ABORT),
    OPT_CMDMODE(0, "quit", &resume_mode,
      N_("abort the patching operation but keep HEAD where it is"),
      RESUME_QUIT),
    { OPTION_CALLBACK, 0, "show-current-patch", &resume_mode,
      "(diff|raw)",
      N_("show the patch being applied"),
      PARSE_OPT_CMDMODE | PARSE_OPT_OPTARG | PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP,
      parse_opt_show_current_patch, RESUME_SHOW_PATCH_RAW },
    OPT_CMDMODE(0, "retry", &resume_mode,
      N_("try to apply current patch again"),
      RESUME_APPLY),
    OPT_CMDMODE(0, "allow-empty", &resume_mode,
      N_("record the empty patch as an empty commit"),
      RESUME_ALLOW_EMPTY),
    OPT_BOOL(0, "committer-date-is-author-date",
      &state.committer_date_is_author_date,
      N_("lie about committer date")),
    OPT_BOOL(0, "ignore-date", &state.ignore_date,
      N_("use current timestamp for author date")),
    OPT_RERERE_AUTOUPDATE(&state.allow_rerere_autoupdate),
    { OPTION_STRING, 'S', "gpg-sign", &state.sign_commit, N_("key-id"),
      N_("GPG-sign commits"),
      PARSE_OPT_OPTARG, NULL, (intptr_t) "" },
    OPT_CALLBACK_F(0, "empty", &state.empty_type, "(stop|drop|keep)",
      N_("how to handle empty patches"),
      PARSE_OPT_NONEG, am_option_parse_empty),
    OPT_HIDDEN_BOOL(0, "rebasing", &state.rebasing,
      N_("(internal use for git-rebase)")),
    OPT_END()
  };

  if (argc == 2 && !strcmp(argv[1], "-h"))
    usage_with_options(usage, options);

  git_config(git_default_config, NULL);

  am_state_init(&state);

  in_progress = am_in_progress(&state);
  if (in_progress)
    am_load(&state);

  argc = parse_options(argc, argv, prefix, options, usage, 0);

  if (binary >= 0)
    fprintf_ln(stderr, _("The -b/--binary option has been a no-op for long time, and\n"
        "it will be removed. Please do not use it anymore."));

  /* Ensure a valid committer ident can be constructed */
  git_committer_info(IDENT_STRICT);

  if (repo_read_index_preload(the_repository, NULL, 0) < 0)
    die(_("failed to read the index"));

  if (in_progress) {
    /*
     * Catch user error to feed us patches when there is a session
     * in progress:
     *
     * 1. mbox path(s) are provided on the command-line.
     * 2. stdin is not a tty: the user is trying to feed us a patch
     *    from standard input. This is somewhat unreliable -- stdin
     *    could be /dev/null for example and the caller did not
     *    intend to feed us a patch but wanted to continue
     *    unattended.
     */
    if (argc || (resume_mode == RESUME_FALSE && !isatty(0)))
      die(_("previous rebase directory %s still exists but mbox given."),
        state.dir);

    if (resume_mode == RESUME_FALSE)
      resume_mode = RESUME_APPLY;

    if (state.signoff == SIGNOFF_EXPLICIT)
      am_append_signoff(&state);
  } else {
    struct strvec paths = STRVEC_INIT;
    int i;

    /*
     * Handle stray state directory in the independent-run case. In
     * the --rebasing case, it is up to the caller to take care of
     * stray directories.
     */
    if (file_exists(state.dir) && !state.rebasing) {
      if (resume_mode == RESUME_ABORT || resume_mode == RESUME_QUIT) {
        am_destroy(&state);
        am_state_release(&state);
        return 0;
      }

      die(_("Stray %s directory found.\n"
        "Use \"git am --abort\" to remove it."),
        state.dir);
    }

    if (resume_mode)
      die(_("Resolve operation not in progress, we are not resuming."));

    for (i = 0; i < argc; i++) {
      if (is_absolute_path(argv[i]) || !prefix)
        strvec_push(&paths, argv[i]);
      else
        strvec_push(&paths, mkpath("%s/%s", prefix, argv[i]));
    }

    if (state.interactive && !paths.nr)
      die(_("interactive mode requires patches on the command line"));

    am_setup(&state, patch_format, paths.v, keep_cr);

    strvec_clear(&paths);
  }

  switch (resume_mode) {
  case RESUME_FALSE:
    am_run(&state, 0);
    break;
  case RESUME_APPLY:
    am_run(&state, 1);
    break;
  case RESUME_RESOLVED:
  case RESUME_ALLOW_EMPTY:
    am_resolve(&state, resume_mode == RESUME_ALLOW_EMPTY ? 1 : 0);
    break;
  case RESUME_SKIP:
    am_skip(&state);
    break;
  case RESUME_ABORT:
    am_abort(&state);
    break;
  case RESUME_QUIT:
    am_rerere_clear();
    am_destroy(&state);
    break;
  case RESUME_SHOW_PATCH_RAW:
  case RESUME_SHOW_PATCH_DIFF:
    ret = show_patch(&state, resume_mode);
    break;
  default:
    BUG("invalid resume value");
  }

  am_state_release(&state);

  return ret;
}

Coverage Report

Created: 2024-09-08 06:24