/src/git/pretty.c

Source
#define USE_THE_REPOSITORY_VARIABLE
#define DISABLE_SIGN_COMPARE_WARNINGS

#include "git-compat-util.h"
#include "config.h"
#include "commit.h"
#include "environment.h"
#include "gettext.h"
#include "hash.h"
#include "hex.h"
#include "utf8.h"
#include "diff.h"
#include "pager.h"
#include "revision.h"
#include "string-list.h"
#include "mailmap.h"
#include "log-tree.h"
#include "notes.h"
#include "color.h"
#include "reflog-walk.h"
#include "gpg-interface.h"
#include "trailer.h"
#include "run-command.h"
#include "object-name.h"

/*
 * The limit for formatting directives, which enable the caller to append
 * arbitrarily many bytes to the formatted buffer. This includes padding
 * and wrapping formatters.
 */
#define FORMATTING_LIMIT (16 * 1024)

static char *user_format;
static struct cmt_fmt_map {
  const char *name;
  enum cmit_fmt format;
  int is_tformat;
  int expand_tabs_in_log;
  int is_alias;
  enum date_mode_type default_date_mode_type;
  const char *user_format;
} *commit_formats;
static size_t builtin_formats_len;
static size_t commit_formats_len;
static size_t commit_formats_alloc;
static struct cmt_fmt_map *find_commit_format(const char *sought);

int commit_format_is_empty(enum cmit_fmt fmt)
{
  return fmt == CMIT_FMT_USERFORMAT && !*user_format;
}

static void save_user_format(struct rev_info *rev, const char *cp, int is_tformat)
{
  free(user_format);
  user_format = xstrdup(cp);
  if (is_tformat)
    rev->use_terminator = 1;
  rev->commit_format = CMIT_FMT_USERFORMAT;
}

static int git_pretty_formats_config(const char *var, const char *value,
             const struct config_context *ctx UNUSED,
             void *cb UNUSED)
{
  struct cmt_fmt_map *commit_format = NULL;
  const char *name, *stripped;
  char *fmt;
  int i;

  if (!skip_prefix(var, "pretty.", &name))
    return 0;

  for (i = 0; i < builtin_formats_len; i++) {
    if (!strcmp(commit_formats[i].name, name))
      return 0;
  }

  for (i = builtin_formats_len; i < commit_formats_len; i++) {
    if (!strcmp(commit_formats[i].name, name)) {
      commit_format = &commit_formats[i];
      break;
    }
  }

  if (!commit_format) {
    ALLOC_GROW(commit_formats, commit_formats_len+1,
         commit_formats_alloc);
    commit_format = &commit_formats[commit_formats_len];
    memset(commit_format, 0, sizeof(*commit_format));
    commit_formats_len++;
  }

  free((char *)commit_format->name);
  commit_format->name = xstrdup(name);
  commit_format->format = CMIT_FMT_USERFORMAT;
  if (git_config_string(&fmt, var, value))
    return -1;

  free((char *)commit_format->user_format);
  if (skip_prefix(fmt, "format:", &stripped)) {
    commit_format->is_tformat = 0;
    commit_format->user_format = xstrdup(stripped);
    free(fmt);
  } else if (skip_prefix(fmt, "tformat:", &stripped)) {
    commit_format->is_tformat = 1;
    commit_format->user_format = xstrdup(stripped);
    free(fmt);
  } else if (strchr(fmt, '%')) {
    commit_format->is_tformat = 1;
    commit_format->user_format = fmt;
  } else {
    commit_format->is_alias = 1;
    commit_format->user_format = fmt;
  }

  return 0;
}

static void setup_commit_formats(void)
{
  struct cmt_fmt_map builtin_formats[] = {
    { "raw",  CMIT_FMT_RAW,   0,  0 },
    { "medium", CMIT_FMT_MEDIUM,  0,  8 },
    { "short",  CMIT_FMT_SHORT,   0,  0 },
    { "email",  CMIT_FMT_EMAIL,   0,  0 },
    { "mboxrd", CMIT_FMT_MBOXRD,  0,  0 },
    { "fuller", CMIT_FMT_FULLER,  0,  8 },
    { "full", CMIT_FMT_FULL,    0,  8 },
    { "oneline",  CMIT_FMT_ONELINE, 1,  0 },
    { "reference",  CMIT_FMT_USERFORMAT,  1,  0,
      0, DATE_SHORT, "%C(auto)%h (%s, %ad)" },
    /*
     * Please update $__git_log_pretty_formats in
     * git-completion.bash when you add new formats.
     */
  };
  commit_formats_len = ARRAY_SIZE(builtin_formats);
  builtin_formats_len = commit_formats_len;
  ALLOC_GROW(commit_formats, commit_formats_len, commit_formats_alloc);
  COPY_ARRAY(commit_formats, builtin_formats,
       ARRAY_SIZE(builtin_formats));

  repo_config(the_repository, git_pretty_formats_config, NULL);
}

static struct cmt_fmt_map *find_commit_format_recursive(const char *sought,
              const char *original,
              int num_redirections)
{
  struct cmt_fmt_map *found = NULL;
  size_t found_match_len = 0;
  int i;

  if (num_redirections >= commit_formats_len)
    die("invalid --pretty format: "
        "'%s' references an alias which points to itself",
        original);

  for (i = 0; i < commit_formats_len; i++) {
    size_t match_len;

    if (!istarts_with(commit_formats[i].name, sought))
      continue;

    match_len = strlen(commit_formats[i].name);
    if (found == NULL || found_match_len > match_len) {
      found = &commit_formats[i];
      found_match_len = match_len;
    }
  }

  if (found && found->is_alias) {
    found = find_commit_format_recursive(found->user_format,
                 original,
                 num_redirections+1);
  }

  return found;
}

static struct cmt_fmt_map *find_commit_format(const char *sought)
{
  if (!commit_formats)
    setup_commit_formats();

  return find_commit_format_recursive(sought, sought, 0);
}

void get_commit_format(const char *arg, struct rev_info *rev)
{
  struct cmt_fmt_map *commit_format;

  rev->use_terminator = 0;
  if (!arg) {
    rev->commit_format = CMIT_FMT_DEFAULT;
    return;
  }
  if (skip_prefix(arg, "format:", &arg)) {
    save_user_format(rev, arg, 0);
    return;
  }

  if (!*arg || skip_prefix(arg, "tformat:", &arg) || strchr(arg, '%')) {
    save_user_format(rev, arg, 1);
    return;
  }

  commit_format = find_commit_format(arg);
  if (!commit_format)
    die("invalid --pretty format: %s", arg);

  rev->commit_format = commit_format->format;
  rev->use_terminator = commit_format->is_tformat;
  rev->expand_tabs_in_log_default = commit_format->expand_tabs_in_log;
  if (!rev->date_mode_explicit && commit_format->default_date_mode_type)
    rev->date_mode.type = commit_format->default_date_mode_type;
  if (commit_format->format == CMIT_FMT_USERFORMAT) {
    save_user_format(rev, commit_format->user_format,
         commit_format->is_tformat);
  }
}

/*
 * Generic support for pretty-printing the header
 */
static int get_one_line(const char *msg)
{
  int ret = 0;

  for (;;) {
    char c = *msg++;
    if (!c)
      break;
    ret++;
    if (c == '\n')
      break;
  }
  return ret;
}

/* High bit set, or ISO-2022-INT */
static int non_ascii(int ch)
{
  return !isascii(ch) || ch == '\033';
}

int has_non_ascii(const char *s)
{
  int ch;
  if (!s)
    return 0;
  while ((ch = *s++) != '\0') {
    if (non_ascii(ch))
      return 1;
  }
  return 0;
}

static int is_rfc822_special(char ch)
{
  switch (ch) {
  case '(':
  case ')':
  case '<':
  case '>':
  case '[':
  case ']':
  case ':':
  case ';':
  case '@':
  case ',':
  case '.':
  case '"':
  case '\\':
    return 1;
  default:
    return 0;
  }
}

static int needs_rfc822_quoting(const char *s, int len)
{
  int i;
  for (i = 0; i < len; i++)
    if (is_rfc822_special(s[i]))
      return 1;
  return 0;
}

static int last_line_length(struct strbuf *sb)
{
  int i;

  /* How many bytes are already used on the last line? */
  for (i = sb->len - 1; i >= 0; i--)
    if (sb->buf[i] == '\n')
      break;
  return sb->len - (i + 1);
}

static void add_rfc822_quoted(struct strbuf *out, const char *s, int len)
{
  int i;

  /* just a guess, we may have to also backslash-quote */
  strbuf_grow(out, len + 2);

  strbuf_addch(out, '"');
  for (i = 0; i < len; i++) {
    switch (s[i]) {
    case '"':
    case '\\':
      strbuf_addch(out, '\\');
      /* fall through */
    default:
      strbuf_addch(out, s[i]);
    }
  }
  strbuf_addch(out, '"');
}

enum rfc2047_type {
  RFC2047_SUBJECT,
  RFC2047_ADDRESS
};

static int is_rfc2047_special(char ch, enum rfc2047_type type)
{
  /*
   * rfc2047, section 4.2:
   *
   *    8-bit values which correspond to printable ASCII characters other
   *    than "=", "?", and "_" (underscore), MAY be represented as those
   *    characters.  (But see section 5 for restrictions.)  In
   *    particular, SPACE and TAB MUST NOT be represented as themselves
   *    within encoded words.
   */

  /*
   * rule out non-ASCII characters and non-printable characters (the
   * non-ASCII check should be redundant as isprint() is not localized
   * and only knows about ASCII, but be defensive about that)
   */
  if (non_ascii(ch) || !isprint(ch))
    return 1;

  /*
   * rule out special printable characters (' ' should be the only
   * whitespace character considered printable, but be defensive and use
   * isspace())
   */
  if (isspace(ch) || ch == '=' || ch == '?' || ch == '_')
    return 1;

  /*
   * rfc2047, section 5.3:
   *
   *    As a replacement for a 'word' entity within a 'phrase', for example,
   *    one that precedes an address in a From, To, or Cc header.  The ABNF
   *    definition for 'phrase' from RFC 822 thus becomes:
   *
   *    phrase = 1*( encoded-word / word )
   *
   *    In this case the set of characters that may be used in a "Q"-encoded
   *    'encoded-word' is restricted to: <upper and lower case ASCII
   *    letters, decimal digits, "!", "*", "+", "-", "/", "=", and "_"
   *    (underscore, ASCII 95.)>.  An 'encoded-word' that appears within a
   *    'phrase' MUST be separated from any adjacent 'word', 'text' or
   *    'special' by 'linear-white-space'.
   */

  if (type != RFC2047_ADDRESS)
    return 0;

  /* '=' and '_' are special cases and have been checked above */
  return !(isalnum(ch) || ch == '!' || ch == '*' || ch == '+' || ch == '-' || ch == '/');
}

static int needs_rfc2047_encoding(const char *line, int len)
{
  int i;

  for (i = 0; i < len; i++) {
    int ch = line[i];
    if (non_ascii(ch) || ch == '\n')
      return 1;
    if ((i + 1 < len) && (ch == '=' && line[i+1] == '?'))
      return 1;
  }

  return 0;
}

static void add_rfc2047(struct strbuf *sb, const char *line, size_t len,
           const char *encoding, enum rfc2047_type type)
{
  static const int max_encoded_length = 76; /* per rfc2047 */
  int i;
  int line_len = last_line_length(sb);

  strbuf_addf(sb, "=?%s?q?", encoding);
  line_len += strlen(encoding) + 5; /* 5 for =??q? */

  while (len) {
    /*
     * RFC 2047, section 5 (3):
     *
     * Each 'encoded-word' MUST represent an integral number of
     * characters.  A multi-octet character may not be split across
     * adjacent 'encoded- word's.
     */
    const unsigned char *p = (const unsigned char *)line;
    int chrlen = mbs_chrlen(&line, &len, encoding);
    int is_special = (chrlen > 1) || is_rfc2047_special(*p, type);

    /* "=%02X" * chrlen, or the byte itself */
    const char *encoded_fmt = is_special ? "=%02X"    : "%c";
    int     encoded_len = is_special ? 3 * chrlen : 1;

    /*
     * According to RFC 2047, we could encode the special character
     * ' ' (space) with '_' (underscore) for readability. But many
     * programs do not understand this and just leave the
     * underscore in place. Thus, we do nothing special here, which
     * causes ' ' to be encoded as '=20', avoiding this problem.
     */

    if (line_len + encoded_len + 2 > max_encoded_length) {
      /* It won't fit with trailing "?=" --- break the line */
      strbuf_addf(sb, "?=\n =?%s?q?", encoding);
      line_len = strlen(encoding) + 5 + 1; /* =??q? plus SP */
    }

    for (i = 0; i < chrlen; i++)
      strbuf_addf(sb, encoded_fmt, p[i]);
    line_len += encoded_len;
  }
  strbuf_addstr(sb, "?=");
}

const char *show_ident_date(const struct ident_split *ident,
          struct date_mode mode)
{
  timestamp_t date = 0;
  long tz = 0;

  if (ident->date_begin && ident->date_end)
    date = parse_timestamp(ident->date_begin, NULL, 10);
  if (date_overflows(date))
    date = 0;
  else {
    if (ident->tz_begin && ident->tz_end)
      tz = strtol(ident->tz_begin, NULL, 10);
    if (tz >= INT_MAX || tz <= INT_MIN)
      tz = 0;
  }
  return show_date(date, tz, mode);
}

static inline void strbuf_add_with_color(struct strbuf *sb, const char *color,
           const char *buf, size_t buflen)
{
  strbuf_addstr(sb, color);
  strbuf_add(sb, buf, buflen);
  if (*color)
    strbuf_addstr(sb, GIT_COLOR_RESET);
}

static void append_line_with_color(struct strbuf *sb, struct grep_opt *opt,
           const char *line, size_t linelen,
           enum git_colorbool color, enum grep_context ctx,
           enum grep_header_field field)
{
  const char *buf, *eol, *line_color, *match_color;
  regmatch_t match;
  int eflags = 0;

  buf = line;
  eol = buf + linelen;

  if (!opt || !want_color(color) || opt->invert)
    goto end;

  line_color = opt->colors[GREP_COLOR_SELECTED];
  match_color = opt->colors[GREP_COLOR_MATCH_SELECTED];

  while (grep_next_match(opt, buf, eol, ctx, &match, field, eflags)) {
    if (match.rm_so == match.rm_eo)
      break;

    strbuf_add_with_color(sb, line_color, buf, match.rm_so);
    strbuf_add_with_color(sb, match_color, buf + match.rm_so,
              match.rm_eo - match.rm_so);
    buf += match.rm_eo;
    eflags = REG_NOTBOL;
  }

  if (eflags)
    strbuf_add_with_color(sb, line_color, buf, eol - buf);
  else {
end:
    strbuf_add(sb, buf, eol - buf);
  }
}

static int use_in_body_from(const struct pretty_print_context *pp,
          const struct ident_split *ident)
{
  if (pp->rev && pp->rev->force_in_body_from)
    return 1;
  if (ident_cmp(pp->from_ident, ident))
    return 1;
  return 0;
}

void pp_user_info(struct pretty_print_context *pp,
      const char *what, struct strbuf *sb,
      const char *line, const char *encoding)
{
  struct ident_split ident;
  char *line_end;
  const char *mailbuf, *namebuf;
  size_t namelen, maillen;
  int max_length = 78; /* per rfc2822 */

  if (pp->fmt == CMIT_FMT_ONELINE)
    return;

  line_end = strchrnul(line, '\n');
  if (split_ident_line(&ident, line, line_end - line))
    return;

  mailbuf = ident.mail_begin;
  maillen = ident.mail_end - ident.mail_begin;
  namebuf = ident.name_begin;
  namelen = ident.name_end - ident.name_begin;

  if (pp->mailmap)
    map_user(pp->mailmap, &mailbuf, &maillen, &namebuf, &namelen);

  if (cmit_fmt_is_mail(pp->fmt)) {
    if (pp->from_ident && use_in_body_from(pp, &ident)) {
      struct strbuf buf = STRBUF_INIT;

      strbuf_addstr(&buf, "From: ");
      strbuf_add(&buf, namebuf, namelen);
      strbuf_addstr(&buf, " <");
      strbuf_add(&buf, mailbuf, maillen);
      strbuf_addstr(&buf, ">\n");
      string_list_append(&pp->in_body_headers,
             strbuf_detach(&buf, NULL));

      mailbuf = pp->from_ident->mail_begin;
      maillen = pp->from_ident->mail_end - mailbuf;
      namebuf = pp->from_ident->name_begin;
      namelen = pp->from_ident->name_end - namebuf;
    }

    strbuf_addstr(sb, "From: ");
    if (pp->encode_email_headers &&
        needs_rfc2047_encoding(namebuf, namelen)) {
      add_rfc2047(sb, namebuf, namelen,
            encoding, RFC2047_ADDRESS);
      max_length = 76; /* per rfc2047 */
    } else if (needs_rfc822_quoting(namebuf, namelen)) {
      struct strbuf quoted = STRBUF_INIT;
      add_rfc822_quoted(&quoted, namebuf, namelen);
      strbuf_add_wrapped_bytes(sb, quoted.buf, quoted.len,
              -6, 1, max_length);
      strbuf_release(&quoted);
    } else {
      strbuf_add_wrapped_bytes(sb, namebuf, namelen,
             -6, 1, max_length);
    }

    if (max_length <
        last_line_length(sb) + strlen(" <") + maillen + strlen(">"))
      strbuf_addch(sb, '\n');
    strbuf_addf(sb, " <%.*s>\n", (int)maillen, mailbuf);
  } else {
    struct strbuf id = STRBUF_INIT;
    enum grep_header_field field = GREP_HEADER_FIELD_MAX;
    struct grep_opt *opt = pp->rev ? &pp->rev->grep_filter : NULL;

    if (!strcmp(what, "Author"))
      field = GREP_HEADER_AUTHOR;
    else if (!strcmp(what, "Commit"))
      field = GREP_HEADER_COMMITTER;

    strbuf_addf(sb, "%s: ", what);
    if (pp->fmt == CMIT_FMT_FULLER)
      strbuf_addchars(sb, ' ', 4);

    strbuf_addf(&id, "%.*s <%.*s>", (int)namelen, namebuf,
          (int)maillen, mailbuf);

    append_line_with_color(sb, opt, id.buf, id.len, pp->color,
               GREP_CONTEXT_HEAD, field);
    strbuf_addch(sb, '\n');
    strbuf_release(&id);
  }

  switch (pp->fmt) {
  case CMIT_FMT_MEDIUM:
    strbuf_addf(sb, "Date:   %s\n",
          show_ident_date(&ident, pp->date_mode));
    break;
  case CMIT_FMT_EMAIL:
  case CMIT_FMT_MBOXRD:
    strbuf_addf(sb, "Date: %s\n",
          show_ident_date(&ident, DATE_MODE(RFC2822)));
    break;
  case CMIT_FMT_FULLER:
    strbuf_addf(sb, "%sDate: %s\n", what,
          show_ident_date(&ident, pp->date_mode));
    break;
  default:
    /* notin' */
    break;
  }
}

static int is_blank_line(const char *line, int *len_p)
{
  int len = *len_p;
  while (len && isspace(line[len - 1]))
    len--;
  *len_p = len;
  return !len;
}

const char *skip_blank_lines(const char *msg)
{
  for (;;) {
    int linelen = get_one_line(msg);
    int ll = linelen;
    if (!linelen)
      break;
    if (!is_blank_line(msg, &ll))
      break;
    msg += linelen;
  }
  return msg;
}

static void add_merge_info(const struct pretty_print_context *pp,
         struct strbuf *sb, const struct commit *commit)
{
  struct commit_list *parent = commit->parents;

  if ((pp->fmt == CMIT_FMT_ONELINE) || (cmit_fmt_is_mail(pp->fmt)) ||
      !parent || !parent->next)
    return;

  strbuf_addstr(sb, "Merge:");

  while (parent) {
    struct object_id *oidp = &parent->item->object.oid;
    strbuf_addch(sb, ' ');
    if (pp->abbrev)
      strbuf_add_unique_abbrev(sb, oidp, pp->abbrev);
    else
      strbuf_add_oid_hex(sb, oidp);
    parent = parent->next;
  }
  strbuf_addch(sb, '\n');
}

static char *get_header(const char *msg, const char *key)
{
  size_t len;
  const char *v = find_commit_header(msg, key, &len);
  return v ? xmemdupz(v, len) : NULL;
}

static char *replace_encoding_header(char *buf, const char *encoding)
{
  struct strbuf tmp = STRBUF_INIT;
  size_t start, len;
  char *cp = buf;

  /* guess if there is an encoding header before a \n\n */
  while (!starts_with(cp, "encoding ")) {
    cp = strchr(cp, '\n');
    if (!cp || *++cp == '\n')
      return buf;
  }
  start = cp - buf;
  cp = strchr(cp, '\n');
  if (!cp)
    return buf; /* should not happen but be defensive */
  len = cp + 1 - (buf + start);

  strbuf_attach(&tmp, buf, strlen(buf), strlen(buf) + 1);
  if (is_encoding_utf8(encoding)) {
    /* we have re-coded to UTF-8; drop the header */
    strbuf_remove(&tmp, start, len);
  } else {
    /* just replaces XXXX in 'encoding XXXX\n' */
    strbuf_splice(&tmp, start + strlen("encoding "),
            len - strlen("encoding \n"),
            encoding, strlen(encoding));
  }
  return strbuf_detach(&tmp, NULL);
}

const char *repo_logmsg_reencode(struct repository *r,
         const struct commit *commit,
         char **commit_encoding,
         const char *output_encoding)
{
  static const char *utf8 = "UTF-8";
  const char *use_encoding;
  char *encoding;
  const char *msg = repo_get_commit_buffer(r, commit, NULL);
  char *out;

  if (!output_encoding || !*output_encoding) {
    if (commit_encoding)
      *commit_encoding = get_header(msg, "encoding");
    return msg;
  }
  encoding = get_header(msg, "encoding");
  if (commit_encoding)
    *commit_encoding = encoding;
  use_encoding = encoding ? encoding : utf8;
  if (same_encoding(use_encoding, output_encoding)) {
    /*
     * No encoding work to be done. If we have no encoding header
     * at all, then there's nothing to do, and we can return the
     * message verbatim (whether newly allocated or not).
     */
    if (!encoding)
      return msg;

    /*
     * Otherwise, we still want to munge the encoding header in the
     * result, which will be done by modifying the buffer. If we
     * are using a fresh copy, we can reuse it. But if we are using
     * the cached copy from repo_get_commit_buffer, we need to duplicate it
     * to avoid munging the cached copy.
     */
    if (msg == get_cached_commit_buffer(r, commit, NULL))
      out = xstrdup(msg);
    else
      out = (char *)msg;
  }
  else {
    /*
     * There's actual encoding work to do. Do the reencoding, which
     * still leaves the header to be replaced in the next step. At
     * this point, we are done with msg. If we allocated a fresh
     * copy, we can free it.
     */
    out = reencode_string(msg, output_encoding, use_encoding);
    if (out)
      repo_unuse_commit_buffer(r, commit, msg);
  }

  /*
   * This replacement actually consumes the buffer we hand it, so we do
   * not have to worry about freeing the old "out" here.
   */
  if (out)
    out = replace_encoding_header(out, output_encoding);

  if (!commit_encoding)
    free(encoding);
  /*
   * If the re-encoding failed, out might be NULL here; in that
   * case we just return the commit message verbatim.
   */
  return out ? out : msg;
}

static int mailmap_name(const char **email, size_t *email_len,
      const char **name, size_t *name_len)
{
  static struct string_list *mail_map;
  if (!mail_map) {
    CALLOC_ARRAY(mail_map, 1);
    read_mailmap(the_repository, mail_map);
  }
  return mail_map->nr && map_user(mail_map, email, email_len, name, name_len);
}

static size_t format_person_part(struct strbuf *sb, char part,
         const char *msg, int len,
         struct date_mode dmode)
{
  /* currently all placeholders have same length */
  const int placeholder_len = 2;
  struct ident_split s;
  const char *name, *mail;
  size_t maillen, namelen;

  if (split_ident_line(&s, msg, len) < 0)
    goto skip;

  name = s.name_begin;
  namelen = s.name_end - s.name_begin;
  mail = s.mail_begin;
  maillen = s.mail_end - s.mail_begin;

  if (part == 'N' || part == 'E' || part == 'L') /* mailmap lookup */
    mailmap_name(&mail, &maillen, &name, &namelen);
  if (part == 'n' || part == 'N') { /* name */
    strbuf_add(sb, name, namelen);
    return placeholder_len;
  }
  if (part == 'e' || part == 'E') { /* email */
    strbuf_add(sb, mail, maillen);
    return placeholder_len;
  }
  if (part == 'l' || part == 'L') { /* local-part */
    const char *at = memchr(mail, '@', maillen);
    if (at)
      maillen = at - mail;
    strbuf_add(sb, mail, maillen);
    return placeholder_len;
  }

  if (!s.date_begin)
    goto skip;

  if (part == 't') { /* date, UNIX timestamp */
    strbuf_add(sb, s.date_begin, s.date_end - s.date_begin);
    return placeholder_len;
  }

  switch (part) {
  case 'd': /* date */
    strbuf_addstr(sb, show_ident_date(&s, dmode));
    return placeholder_len;
  case 'D': /* date, RFC2822 style */
    strbuf_addstr(sb, show_ident_date(&s, DATE_MODE(RFC2822)));
    return placeholder_len;
  case 'r': /* date, relative */
    strbuf_addstr(sb, show_ident_date(&s, DATE_MODE(RELATIVE)));
    return placeholder_len;
  case 'i': /* date, ISO 8601-like */
    strbuf_addstr(sb, show_ident_date(&s, DATE_MODE(ISO8601)));
    return placeholder_len;
  case 'I': /* date, ISO 8601 strict */
    strbuf_addstr(sb, show_ident_date(&s, DATE_MODE(ISO8601_STRICT)));
    return placeholder_len;
  case 'h': /* date, human */
    strbuf_addstr(sb, show_ident_date(&s, DATE_MODE(HUMAN)));
    return placeholder_len;
  case 's':
    strbuf_addstr(sb, show_ident_date(&s, DATE_MODE(SHORT)));
    return placeholder_len;
  }

skip:
  /*
   * reading from either a bogus commit, or a reflog entry with
   * %gn, %ge, etc.; 'sb' cannot be updated, but we still need
   * to compute a valid return value.
   */
  if (part == 'n' || part == 'e' || part == 't' || part == 'd'
      || part == 'D' || part == 'r' || part == 'i')
    return placeholder_len;

  return 0; /* unknown placeholder */
}

struct chunk {
  size_t off;
  size_t len;
};

enum flush_type {
  no_flush,
  flush_right,
  flush_left,
  flush_left_and_steal,
  flush_both
};

enum trunc_type {
  trunc_none,
  trunc_left,
  trunc_middle,
  trunc_right
};

struct format_commit_context {
  struct repository *repository;
  const struct commit *commit;
  const struct pretty_print_context *pretty_ctx;
  unsigned commit_header_parsed:1;
  unsigned commit_message_parsed:1;
  struct signature_check signature_check;
  enum flush_type flush_type;
  enum trunc_type truncate;
  const char *message;
  char *commit_encoding;
  size_t width, indent1, indent2;
  enum git_colorbool auto_color;
  int padding;

  /* These offsets are relative to the start of the commit message. */
  struct chunk author;
  struct chunk committer;
  size_t message_off;
  size_t subject_off;
  size_t body_off;

  /* The following ones are relative to the result struct strbuf. */
  size_t wrap_start;
};

static void parse_commit_header(struct format_commit_context *context)
{
  const char *msg = context->message;
  int i;

  for (i = 0; msg[i]; i++) {
    const char *name;
    int eol;
    for (eol = i; msg[eol] && msg[eol] != '\n'; eol++)
      ; /* do nothing */

    if (i == eol) {
      break;
    } else if (skip_prefix(msg + i, "author ", &name)) {
      context->author.off = name - msg;
      context->author.len = msg + eol - name;
    } else if (skip_prefix(msg + i, "committer ", &name)) {
      context->committer.off = name - msg;
      context->committer.len = msg + eol - name;
    }
    i = eol;
  }
  context->message_off = i;
  context->commit_header_parsed = 1;
}

static int istitlechar(char c)
{
  return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') ||
    (c >= '0' && c <= '9') || c == '.' || c == '_';
}

void format_sanitized_subject(struct strbuf *sb, const char *msg, size_t len)
{
  size_t trimlen;
  size_t start_len = sb->len;
  int space = 2;
  int i;

  for (i = 0; i < len; i++) {
    if (istitlechar(msg[i])) {
      if (space == 1)
        strbuf_addch(sb, '-');
      space = 0;
      strbuf_addch(sb, msg[i]);
      if (msg[i] == '.')
        while (msg[i+1] == '.')
          i++;
    } else
      space |= 1;
  }

  /* trim any trailing '.' or '-' characters */
  trimlen = 0;
  while (sb->len - trimlen > start_len &&
    (sb->buf[sb->len - 1 - trimlen] == '.'
    || sb->buf[sb->len - 1 - trimlen] == '-'))
    trimlen++;
  strbuf_remove(sb, sb->len - trimlen, trimlen);
}

const char *format_subject(struct strbuf *sb, const char *msg,
         const char *line_separator)
{
  int first = 1;

  for (;;) {
    const char *line = msg;
    int linelen = get_one_line(line);

    msg += linelen;
    if (!linelen || is_blank_line(line, &linelen))
      break;

    if (!sb)
      continue;
    strbuf_grow(sb, linelen + 2);
    if (!first)
      strbuf_addstr(sb, line_separator);
    strbuf_add(sb, line, linelen);
    first = 0;
  }
  return msg;
}

static void parse_commit_message(struct format_commit_context *c)
{
  const char *msg = c->message + c->message_off;
  const char *start = c->message;

  msg = skip_blank_lines(msg);
  c->subject_off = msg - start;

  msg = format_subject(NULL, msg, NULL);
  msg = skip_blank_lines(msg);
  c->body_off = msg - start;

  c->commit_message_parsed = 1;
}

static void strbuf_wrap(struct strbuf *sb, size_t pos,
      size_t width, size_t indent1, size_t indent2)
{
  struct strbuf tmp = STRBUF_INIT;

  if (pos)
    strbuf_add(&tmp, sb->buf, pos);
  strbuf_add_wrapped_text(&tmp, sb->buf + pos,
        cast_size_t_to_int(indent1),
        cast_size_t_to_int(indent2),
        cast_size_t_to_int(width));
  strbuf_swap(&tmp, sb);
  strbuf_release(&tmp);
}

static void rewrap_message_tail(struct strbuf *sb,
        struct format_commit_context *c,
        size_t new_width, size_t new_indent1,
        size_t new_indent2)
{
  if (c->width == new_width && c->indent1 == new_indent1 &&
      c->indent2 == new_indent2)
    return;
  if (c->wrap_start < sb->len)
    strbuf_wrap(sb, c->wrap_start, c->width, c->indent1, c->indent2);
  c->wrap_start = sb->len;
  c->width = new_width;
  c->indent1 = new_indent1;
  c->indent2 = new_indent2;
}

static int format_reflog_person(struct strbuf *sb,
        char part,
        struct reflog_walk_info *log,
        struct date_mode dmode)
{
  const char *ident;

  if (!log)
    return 2;

  ident = get_reflog_ident(log);
  if (!ident)
    return 2;

  return format_person_part(sb, part, ident, strlen(ident), dmode);
}

static size_t parse_color(struct strbuf *sb, /* in UTF-8 */
        const char *placeholder,
        struct format_commit_context *c)
{
  const char *rest = placeholder;
  const char *basic_color = NULL;

  if (placeholder[1] == '(') {
    const char *begin = placeholder + 2;
    const char *end = strchr(begin, ')');
    char color[COLOR_MAXLEN];

    if (!end)
      return 0;

    if (skip_prefix(begin, "auto,", &begin)) {
      if (!want_color(c->pretty_ctx->color))
        return end - placeholder + 1;
    } else if (skip_prefix(begin, "always,", &begin)) {
      /* nothing to do; we do not respect want_color at all */
    } else {
      /* the default is the same as "auto" */
      if (!want_color(c->pretty_ctx->color))
        return end - placeholder + 1;
    }

    if (color_parse_mem(begin, end - begin, color) < 0)
      die(_("unable to parse --pretty format"));
    strbuf_addstr(sb, color);
    return end - placeholder + 1;
  }

  /*
   * We handle things like "%C(red)" above; for historical reasons, there
   * are a few colors that can be specified without parentheses (and
   * they cannot support things like "auto" or "always" at all).
   */
  if (skip_prefix(placeholder + 1, "red", &rest))
    basic_color = GIT_COLOR_RED;
  else if (skip_prefix(placeholder + 1, "green", &rest))
    basic_color = GIT_COLOR_GREEN;
  else if (skip_prefix(placeholder + 1, "blue", &rest))
    basic_color = GIT_COLOR_BLUE;
  else if (skip_prefix(placeholder + 1, "reset", &rest))
    basic_color = GIT_COLOR_RESET;

  if (basic_color && want_color(c->pretty_ctx->color))
    strbuf_addstr(sb, basic_color);

  return rest - placeholder;
}

static size_t parse_padding_placeholder(const char *placeholder,
          struct format_commit_context *c)
{
  const char *ch = placeholder;
  enum flush_type flush_type;
  int to_column = 0;

  switch (*ch++) {
  case '<':
    flush_type = flush_right;
    break;
  case '>':
    if (*ch == '<') {
      flush_type = flush_both;
      ch++;
    } else if (*ch == '>') {
      flush_type = flush_left_and_steal;
      ch++;
    } else
      flush_type = flush_left;
    break;
  default:
    return 0;
  }

  /* the next value means "wide enough to that column" */
  if (*ch == '|') {
    to_column = 1;
    ch++;
  }

  if (*ch == '(') {
    const char *start = ch + 1;
    const char *end = start + strcspn(start, ",)");
    char *next;
    int width;
    if (!*end || end == start)
      return 0;
    width = strtol(start, &next, 10);

    /*
     * We need to limit the amount of padding, or otherwise this
     * would allow the user to pad the buffer by arbitrarily many
     * bytes and thus cause resource exhaustion.
     */
    if (width < -FORMATTING_LIMIT || width > FORMATTING_LIMIT)
      return 0;

    if (next == start || width == 0)
      return 0;
    if (width < 0) {
      if (to_column)
        width += term_columns();
      if (width < 0)
        return 0;
    }
    c->padding = to_column ? -width : width;
    c->flush_type = flush_type;

    if (*end == ',') {
      start = end + 1;
      end = strchr(start, ')');
      if (!end || end == start)
        return 0;
      if (starts_with(start, "trunc)"))
        c->truncate = trunc_right;
      else if (starts_with(start, "ltrunc)"))
        c->truncate = trunc_left;
      else if (starts_with(start, "mtrunc)"))
        c->truncate = trunc_middle;
      else
        return 0;
    } else
      c->truncate = trunc_none;

    return end - placeholder + 1;
  }
  return 0;
}

static int match_placeholder_arg_value(const char *to_parse, const char *candidate,
               const char **end, const char **valuestart,
               size_t *valuelen)
{
  const char *p;

  if (!(skip_prefix(to_parse, candidate, &p)))
    return 0;
  if (valuestart) {
    if (*p == '=') {
      *valuestart = p + 1;
      *valuelen = strcspn(*valuestart, ",)");
      p = *valuestart + *valuelen;
    } else {
      if (*p != ',' && *p != ')')
        return 0;
      *valuestart = NULL;
      *valuelen = 0;
    }
  }
  if (*p == ',') {
    *end = p + 1;
    return 1;
  }
  if (*p == ')') {
    *end = p;
    return 1;
  }
  return 0;
}

static int match_placeholder_bool_arg(const char *to_parse, const char *candidate,
              const char **end, int *val)
{
  const char *argval;
  char *strval;
  size_t arglen;
  int v;

  if (!match_placeholder_arg_value(to_parse, candidate, end, &argval, &arglen))
    return 0;

  if (!argval) {
    *val = 1;
    return 1;
  }

  strval = xstrndup(argval, arglen);
  v = git_parse_maybe_bool(strval);
  free(strval);

  if (v == -1)
    return 0;

  *val = v;

  return 1;
}

static int format_trailer_match_cb(const struct strbuf *key, void *ud)
{
  const struct string_list *list = ud;
  const struct string_list_item *item;

  for_each_string_list_item (item, list) {
    if (key->len == (uintptr_t)item->util &&
        !strncasecmp(item->string, key->buf, key->len))
      return 1;
  }
  return 0;
}

static struct strbuf *expand_string_arg(struct strbuf *sb,
          const char *argval, size_t arglen)
{
  char *fmt = xstrndup(argval, arglen);
  const char *format = fmt;

  strbuf_reset(sb);
  while (strbuf_expand_step(sb, &format)) {
    size_t len;

    if (skip_prefix(format, "%", &format))
      strbuf_addch(sb, '%');
    else if ((len = strbuf_expand_literal(sb, format)))
      format += len;
    else
      strbuf_addch(sb, '%');
  }
  free(fmt);
  return sb;
}

int format_set_trailers_options(struct process_trailer_options *opts,
        struct string_list *filter_list,
        struct strbuf *sepbuf,
        struct strbuf *kvsepbuf,
        const char **arg,
        char **invalid_arg)
{
  for (;;) {
    const char *argval;
    size_t arglen;

    if (**arg == ')')
      break;

    if (match_placeholder_arg_value(*arg, "key", arg, &argval, &arglen)) {
      uintptr_t len = arglen;

      if (!argval)
        return -1;

      if (len && argval[len - 1] == ':')
        len--;
      string_list_append(filter_list, argval)->util = (char *)len;

      opts->filter = format_trailer_match_cb;
      opts->filter_data = filter_list;
      opts->only_trailers = 1;
    } else if (match_placeholder_arg_value(*arg, "separator", arg, &argval, &arglen)) {
      opts->separator = expand_string_arg(sepbuf, argval, arglen);
    } else if (match_placeholder_arg_value(*arg, "key_value_separator", arg, &argval, &arglen)) {
      opts->key_value_separator = expand_string_arg(kvsepbuf, argval, arglen);
    } else if (!match_placeholder_bool_arg(*arg, "only", arg, &opts->only_trailers) &&
         !match_placeholder_bool_arg(*arg, "unfold", arg, &opts->unfold) &&
         !match_placeholder_bool_arg(*arg, "keyonly", arg, &opts->key_only) &&
         !match_placeholder_bool_arg(*arg, "valueonly", arg, &opts->value_only)) {
      if (invalid_arg) {
        size_t len = strcspn(*arg, ",)");
        *invalid_arg = xstrndup(*arg, len);
      }
      return -1;
    }
  }
  return 0;
}

static size_t parse_describe_args(const char *start, struct strvec *args)
{
  struct {
    const char *name;
    enum {
      DESCRIBE_ARG_BOOL,
      DESCRIBE_ARG_INTEGER,
      DESCRIBE_ARG_STRING,
    } type;
  }  option[] = {
    { "tags", DESCRIBE_ARG_BOOL},
    { "abbrev", DESCRIBE_ARG_INTEGER },
    { "exclude", DESCRIBE_ARG_STRING },
    { "match", DESCRIBE_ARG_STRING },
  };
  const char *arg = start;

  for (;;) {
    int found = 0;
    const char *argval;
    size_t arglen = 0;
    int optval = 0;
    int i;

    for (i = 0; !found && i < ARRAY_SIZE(option); i++) {
      switch (option[i].type) {
      case DESCRIBE_ARG_BOOL:
        if (match_placeholder_bool_arg(arg, option[i].name, &arg, &optval)) {
          if (optval)
            strvec_pushf(args, "--%s", option[i].name);
          else
            strvec_pushf(args, "--no-%s", option[i].name);
          found = 1;
        }
        break;
      case DESCRIBE_ARG_INTEGER:
        if (match_placeholder_arg_value(arg, option[i].name, &arg,
                &argval, &arglen)) {
          char *endptr;
          if (!arglen)
            return 0;
          strtol(argval, &endptr, 10);
          if (endptr - argval != arglen)
            return 0;
          strvec_pushf(args, "--%s=%.*s", option[i].name, (int)arglen, argval);
          found = 1;
        }
        break;
      case DESCRIBE_ARG_STRING:
        if (match_placeholder_arg_value(arg, option[i].name, &arg,
                &argval, &arglen)) {
          if (!arglen)
            return 0;
          strvec_pushf(args, "--%s=%.*s", option[i].name, (int)arglen, argval);
          found = 1;
        }
        break;
      }
    }
    if (!found)
      break;

  }
  return arg - start;
}


static int parse_decoration_option(const char **arg,
           const char *name,
           char **opt)
{
  const char *argval;
  size_t arglen;

  if (match_placeholder_arg_value(*arg, name, arg, &argval, &arglen)) {
    struct strbuf sb = STRBUF_INIT;

    expand_string_arg(&sb, argval, arglen);
    *opt = strbuf_detach(&sb, NULL);
    return 1;
  }
  return 0;
}

static void parse_decoration_options(const char **arg,
             struct decoration_options *opts)
{
  while (parse_decoration_option(arg, "prefix", &opts->prefix) ||
         parse_decoration_option(arg, "suffix", &opts->suffix) ||
         parse_decoration_option(arg, "separator", &opts->separator) ||
         parse_decoration_option(arg, "pointer", &opts->pointer) ||
         parse_decoration_option(arg, "tag", &opts->tag))
    ;
}

static void free_decoration_options(const struct decoration_options *opts)
{
  free(opts->prefix);
  free(opts->suffix);
  free(opts->separator);
  free(opts->pointer);
  free(opts->tag);
}

static size_t format_commit_one(struct strbuf *sb, /* in UTF-8 */
        const char *placeholder,
        void *context)
{
  struct format_commit_context *c = context;
  const struct commit *commit = c->commit;
  const char *msg = c->message;
  struct commit_list *p;
  const char *arg, *eol;
  size_t res;
  char **slot;

  /* these are independent of the commit */
  res = strbuf_expand_literal(sb, placeholder);
  if (res)
    return res;

  switch (placeholder[0]) {
  case 'C':
    if (starts_with(placeholder + 1, "(auto)")) {
      c->auto_color = c->pretty_ctx->color;
      if (want_color(c->auto_color) && sb->len)
        strbuf_addstr(sb, GIT_COLOR_RESET);
      return 7; /* consumed 7 bytes, "C(auto)" */
    } else {
      int ret = parse_color(sb, placeholder, c);
      if (ret)
        c->auto_color = GIT_COLOR_NEVER;
      /*
       * Otherwise, we decided to treat %C<unknown>
       * as a literal string, and the previous
       * %C(auto) is still valid.
       */
      return ret;
    }
  case 'w':
    if (placeholder[1] == '(') {
      unsigned long width = 0, indent1 = 0, indent2 = 0;
      char *next;
      const char *start = placeholder + 2;
      const char *end = strchr(start, ')');
      if (!end)
        return 0;
      if (end > start) {
        width = strtoul(start, &next, 10);
        if (*next == ',') {
          indent1 = strtoul(next + 1, &next, 10);
          if (*next == ',') {
            indent2 = strtoul(next + 1,
                 &next, 10);
          }
        }
        if (*next != ')')
          return 0;
      }

      /*
       * We need to limit the format here as it allows the
       * user to prepend arbitrarily many bytes to the buffer
       * when rewrapping.
       */
      if (width > FORMATTING_LIMIT ||
          indent1 > FORMATTING_LIMIT ||
          indent2 > FORMATTING_LIMIT)
        return 0;
      rewrap_message_tail(sb, c, width, indent1, indent2);
      return end - placeholder + 1;
    } else
      return 0;

  case '<':
  case '>':
    return parse_padding_placeholder(placeholder, c);
  }

  if (skip_prefix(placeholder, "(describe", &arg)) {
    struct child_process cmd = CHILD_PROCESS_INIT;
    struct strbuf out = STRBUF_INIT;
    struct strbuf err = STRBUF_INIT;
    struct pretty_print_describe_status *describe_status;

    describe_status = c->pretty_ctx->describe_status;
    if (describe_status) {
      if (!describe_status->max_invocations)
        return 0;
      describe_status->max_invocations--;
    }

    cmd.git_cmd = 1;
    strvec_push(&cmd.args, "describe");

    if (*arg == ':') {
      arg++;
      arg += parse_describe_args(arg, &cmd.args);
    }

    if (*arg != ')') {
      child_process_clear(&cmd);
      return 0;
    }

    strvec_push(&cmd.args, oid_to_hex(&commit->object.oid));
    pipe_command(&cmd, NULL, 0, &out, 0, &err, 0);
    strbuf_rtrim(&out);
    strbuf_addbuf(sb, &out);
    strbuf_release(&out);
    strbuf_release(&err);
    return arg - placeholder + 1;
  }

  /* these depend on the commit */
  if (!commit->object.parsed)
    parse_object(the_repository, &commit->object.oid);

  if (starts_with(placeholder, "(count)")) {
    if (!c->pretty_ctx->rev)
      die(_("%s is not supported by this command"), "%(count)");
    strbuf_addf(sb, "%0*d", decimal_width(c->pretty_ctx->rev->total),
          c->pretty_ctx->rev->nr);
    return 7;
  }

  if (starts_with(placeholder, "(total)")) {
    if (!c->pretty_ctx->rev)
      die(_("%s is not supported by this command"), "%(total)");
    strbuf_addf(sb, "%d", c->pretty_ctx->rev->total);
    return 7;
  }

  switch (placeholder[0]) {
  case 'H':   /* commit hash */
    strbuf_addstr(sb, diff_get_color(c->auto_color, DIFF_COMMIT));
    strbuf_add_oid_hex(sb, &commit->object.oid);
    strbuf_addstr(sb, diff_get_color(c->auto_color, DIFF_RESET));
    return 1;
  case 'h':   /* abbreviated commit hash */
    strbuf_addstr(sb, diff_get_color(c->auto_color, DIFF_COMMIT));
    strbuf_add_unique_abbrev(sb, &commit->object.oid,
           c->pretty_ctx->abbrev);
    strbuf_addstr(sb, diff_get_color(c->auto_color, DIFF_RESET));
    return 1;
  case 'T':   /* tree hash */
    strbuf_add_oid_hex(sb, get_commit_tree_oid(commit));
    return 1;
  case 't':   /* abbreviated tree hash */
    strbuf_add_unique_abbrev(sb,
           get_commit_tree_oid(commit),
           c->pretty_ctx->abbrev);
    return 1;
  case 'P':   /* parent hashes */
    for (p = commit->parents; p; p = p->next) {
      if (p != commit->parents)
        strbuf_addch(sb, ' ');
      strbuf_add_oid_hex(sb, &p->item->object.oid);
    }
    return 1;
  case 'p':   /* abbreviated parent hashes */
    for (p = commit->parents; p; p = p->next) {
      if (p != commit->parents)
        strbuf_addch(sb, ' ');
      strbuf_add_unique_abbrev(sb, &p->item->object.oid,
             c->pretty_ctx->abbrev);
    }
    return 1;
  case 'm':   /* left/right/bottom */
    strbuf_addstr(sb, get_revision_mark(NULL, commit));
    return 1;
  case 'd':
    format_decorations(sb, commit, c->auto_color, NULL);
    return 1;
  case 'D':
    {
      const struct decoration_options opts = {
        .prefix = (char *) "",
        .suffix = (char *) "",
      };

      format_decorations(sb, commit, c->auto_color, &opts);
      return 1;
    }
  case 'S':   /* tag/branch like --source */
    if (!(c->pretty_ctx->rev && c->pretty_ctx->rev->sources))
      return 0;
    slot = revision_sources_at(c->pretty_ctx->rev->sources, commit);
    if (!(slot && *slot))
      return 0;
    strbuf_addstr(sb, *slot);
    return 1;
  case 'g':   /* reflog info */
    switch(placeholder[1]) {
    case 'd': /* reflog selector */
    case 'D':
      if (c->pretty_ctx->reflog_info)
        get_reflog_selector(sb,
                c->pretty_ctx->reflog_info,
                c->pretty_ctx->date_mode,
                c->pretty_ctx->date_mode_explicit,
                (placeholder[1] == 'd'));
      return 2;
    case 's': /* reflog message */
      if (c->pretty_ctx->reflog_info)
        get_reflog_message(sb, c->pretty_ctx->reflog_info);
      return 2;
    case 'n':
    case 'N':
    case 'e':
    case 'E':
      return format_reflog_person(sb,
                placeholder[1],
                c->pretty_ctx->reflog_info,
                c->pretty_ctx->date_mode);
    }
    return 0; /* unknown %g placeholder */
  case 'N':
    if (c->pretty_ctx->notes_message) {
      strbuf_addstr(sb, c->pretty_ctx->notes_message);
      return 1;
    }
    return 0;
  }

  if (placeholder[0] == 'G') {
    if (!c->signature_check.result)
      check_commit_signature(c->commit, &(c->signature_check));
    switch (placeholder[1]) {
    case 'G':
      if (c->signature_check.output)
        strbuf_addstr(sb, c->signature_check.output);
      break;
    case '?':
      switch (c->signature_check.result) {
      case 'G':
        switch (c->signature_check.trust_level) {
        case TRUST_UNDEFINED:
        case TRUST_NEVER:
          strbuf_addch(sb, 'U');
          break;
        default:
          strbuf_addch(sb, 'G');
          break;
        }
        break;
      case 'B':
      case 'E':
      case 'N':
      case 'X':
      case 'Y':
      case 'R':
        strbuf_addch(sb, c->signature_check.result);
      }
      break;
    case 'S':
      if (c->signature_check.signer)
        strbuf_addstr(sb, c->signature_check.signer);
      break;
    case 'K':
      if (c->signature_check.key)
        strbuf_addstr(sb, c->signature_check.key);
      break;
    case 'F':
      if (c->signature_check.fingerprint)
        strbuf_addstr(sb, c->signature_check.fingerprint);
      break;
    case 'P':
      if (c->signature_check.primary_key_fingerprint)
        strbuf_addstr(sb, c->signature_check.primary_key_fingerprint);
      break;
    case 'T':
      strbuf_addstr(sb, gpg_trust_level_to_str(c->signature_check.trust_level));
      break;
    default:
      return 0;
    }
    return 2;
  }

  if (skip_prefix(placeholder, "(decorate", &arg)) {
    struct decoration_options opts = { NULL };
    size_t ret = 0;

    if (*arg == ':') {
      arg++;
      parse_decoration_options(&arg, &opts);
    }
    if (*arg == ')') {
      format_decorations(sb, commit, c->auto_color, &opts);
      ret = arg - placeholder + 1;
    }

    free_decoration_options(&opts);
    return ret;
  }

  /* For the rest we have to parse the commit header. */
  if (!c->commit_header_parsed) {
    msg = c->message =
      repo_logmsg_reencode(c->repository, commit,
               &c->commit_encoding, "UTF-8");
    parse_commit_header(c);
  }

  switch (placeholder[0]) {
  case 'a': /* author ... */
    return format_person_part(sb, placeholder[1],
           msg + c->author.off, c->author.len,
           c->pretty_ctx->date_mode);
  case 'c': /* committer ... */
    return format_person_part(sb, placeholder[1],
           msg + c->committer.off, c->committer.len,
           c->pretty_ctx->date_mode);
  case 'e': /* encoding */
    if (c->commit_encoding)
      strbuf_addstr(sb, c->commit_encoding);
    return 1;
  case 'B': /* raw body */
    /* message_off is always left at the initial newline */
    strbuf_addstr(sb, msg + c->message_off + 1);
    return 1;
  }

  /* Now we need to parse the commit message. */
  if (!c->commit_message_parsed)
    parse_commit_message(c);

  switch (placeholder[0]) {
  case 's': /* subject */
    format_subject(sb, msg + c->subject_off, " ");
    return 1;
  case 'f': /* sanitized subject */
    eol = strchrnul(msg + c->subject_off, '\n');
    format_sanitized_subject(sb, msg + c->subject_off, eol - (msg + c->subject_off));
    return 1;
  case 'b': /* body */
    strbuf_addstr(sb, msg + c->body_off);
    return 1;
  }

  if (skip_prefix(placeholder, "(trailers", &arg)) {
    struct process_trailer_options opts = PROCESS_TRAILER_OPTIONS_INIT;
    struct string_list filter_list = STRING_LIST_INIT_NODUP;
    struct strbuf sepbuf = STRBUF_INIT;
    struct strbuf kvsepbuf = STRBUF_INIT;
    size_t ret = 0;

    opts.no_divider = 1;

    if (*arg == ':') {
      arg++;
      if (format_set_trailers_options(&opts, &filter_list, &sepbuf, &kvsepbuf, &arg, NULL))
        goto trailer_out;
    }
    if (*arg == ')') {
      format_trailers_from_commit(&opts, msg + c->subject_off, sb);
      ret = arg - placeholder + 1;
    }
  trailer_out:
    string_list_clear(&filter_list, 0);
    strbuf_release(&kvsepbuf);
    strbuf_release(&sepbuf);
    return ret;
  }

  return 0; /* unknown placeholder */
}

static size_t format_and_pad_commit(struct strbuf *sb, /* in UTF-8 */
            const char *placeholder,
            struct format_commit_context *c)
{
  struct strbuf local_sb = STRBUF_INIT;
  size_t total_consumed = 0;
  int len, padding = c->padding;

  if (padding < 0) {
    const char *start = strrchr(sb->buf, '\n');
    int occupied;
    if (!start)
      start = sb->buf;
    occupied = utf8_strnwidth(start, strlen(start), 1);
    occupied += c->pretty_ctx->graph_width;
    padding = (-padding) - occupied;
  }
  while (1) {
    int modifier = *placeholder == 'C';
    size_t consumed = format_commit_one(&local_sb, placeholder, c);
    total_consumed += consumed;

    if (!modifier)
      break;

    placeholder += consumed;
    if (*placeholder != '%')
      break;
    placeholder++;
    total_consumed++;
  }
  len = utf8_strnwidth(local_sb.buf, local_sb.len, 1);

  if (c->flush_type == flush_left_and_steal) {
    const char *ch = sb->buf + sb->len - 1;
    while (len > padding && ch > sb->buf) {
      const char *p;
      if (*ch == ' ') {
        ch--;
        padding++;
        continue;
      }
      /* check for trailing ansi sequences */
      if (*ch != 'm')
        break;
      p = ch - 1;
      while (p > sb->buf && ch - p < 10 && *p != '\033')
        p--;
      if (*p != '\033' ||
          ch + 1 - p != display_mode_esc_sequence_len(p))
        break;
      /*
       * got a good ansi sequence, put it back to
       * local_sb as we're cutting sb
       */
      strbuf_insert(&local_sb, 0, p, ch + 1 - p);
      ch = p - 1;
    }
    strbuf_setlen(sb, ch + 1 - sb->buf);
    c->flush_type = flush_left;
  }

  if (len > padding) {
    switch (c->truncate) {
    case trunc_left:
      strbuf_utf8_replace(&local_sb,
              0, len - (padding - 2),
              "..");
      break;
    case trunc_middle:
      strbuf_utf8_replace(&local_sb,
              padding / 2 - 1,
              len - (padding - 2),
              "..");
      break;
    case trunc_right:
      strbuf_utf8_replace(&local_sb,
              padding - 2, len - (padding - 2),
              "..");
      break;
    case trunc_none:
      break;
    }
    strbuf_addbuf(sb, &local_sb);
  } else {
    size_t sb_len = sb->len, offset = 0;
    if (c->flush_type == flush_left)
      offset = padding - len;
    else if (c->flush_type == flush_both)
      offset = (padding - len) / 2;
    /*
     * we calculate padding in columns, now
     * convert it back to chars
     */
    padding = padding - len + local_sb.len;
    strbuf_addchars(sb, ' ', padding);
    memcpy(sb->buf + sb_len + offset, local_sb.buf,
           local_sb.len);
  }
  strbuf_release(&local_sb);
  c->flush_type = no_flush;
  return total_consumed;
}

static size_t format_commit_item(struct strbuf *sb, /* in UTF-8 */
         const char *placeholder,
         struct format_commit_context *context)
{
  size_t consumed, orig_len;
  enum {
    NO_MAGIC,
    ADD_LF_BEFORE_NON_EMPTY,
    DEL_LF_BEFORE_EMPTY,
    ADD_SP_BEFORE_NON_EMPTY
  } magic = NO_MAGIC;

  switch (placeholder[0]) {
  case '-':
    magic = DEL_LF_BEFORE_EMPTY;
    break;
  case '+':
    magic = ADD_LF_BEFORE_NON_EMPTY;
    break;
  case ' ':
    magic = ADD_SP_BEFORE_NON_EMPTY;
    break;
  default:
    break;
  }
  if (magic != NO_MAGIC) {
    placeholder++;

    switch (placeholder[0]) {
    case 'w':
      /*
       * `%+w()` cannot ever expand to a non-empty string,
       * and it potentially changes the layout of preceding
       * contents. We're thus not able to handle the magic in
       * this combination and refuse the pattern.
       */
      return 0;
    };
  }

  orig_len = sb->len;
  if (context->flush_type == no_flush)
    consumed = format_commit_one(sb, placeholder, context);
  else
    consumed = format_and_pad_commit(sb, placeholder, context);
  if (magic == NO_MAGIC)
    return consumed;

  if ((orig_len == sb->len) && magic == DEL_LF_BEFORE_EMPTY) {
    while (sb->len && sb->buf[sb->len - 1] == '\n')
      strbuf_setlen(sb, sb->len - 1);
  } else if (orig_len != sb->len) {
    if (magic == ADD_LF_BEFORE_NON_EMPTY)
      strbuf_insertstr(sb, orig_len, "\n");
    else if (magic == ADD_SP_BEFORE_NON_EMPTY)
      strbuf_insertstr(sb, orig_len, " ");
  }
  return consumed + 1;
}

void userformat_find_requirements(const char *fmt, struct userformat_want *w)
{
  if (!fmt) {
    if (!user_format)
      return;
    fmt = user_format;
  }
  while ((fmt = strchr(fmt, '%'))) {
    fmt++;
    if (skip_prefix(fmt, "%", &fmt))
      continue;

    if (*fmt == '+' || *fmt == '-' || *fmt == ' ')
      fmt++;

    switch (*fmt) {
    case 'N':
      w->notes = 1;
      break;
    case 'S':
      w->source = 1;
      break;
    case 'd':
    case 'D':
      w->decorate = 1;
      break;
    case '(':
      if (starts_with(fmt + 1, "decorate"))
        w->decorate = 1;
      break;
    }
  }
}

void repo_format_commit_message(struct repository *r,
        const struct commit *commit,
        const char *format, struct strbuf *sb,
        const struct pretty_print_context *pretty_ctx)
{
  struct format_commit_context context = {
    .repository = r,
    .commit = commit,
    .pretty_ctx = pretty_ctx,
    .wrap_start = sb->len
  };
  const char *output_enc = pretty_ctx->output_encoding;
  const char *utf8 = "UTF-8";

  while (strbuf_expand_step(sb, &format)) {
    size_t len;

    if (skip_prefix(format, "%", &format))
      strbuf_addch(sb, '%');
    else if ((len = format_commit_item(sb, format, &context)))
      format += len;
    else
      strbuf_addch(sb, '%');
  }
  rewrap_message_tail(sb, &context, 0, 0, 0);

  /*
   * Convert output to an actual output encoding; note that
   * format_commit_item() will always use UTF-8, so we don't
   * have to bother if that's what the output wants.
   */
  if (output_enc) {
    if (same_encoding(utf8, output_enc))
      output_enc = NULL;
  } else {
    if (context.commit_encoding &&
        !same_encoding(context.commit_encoding, utf8))
      output_enc = context.commit_encoding;
  }

  if (output_enc) {
    size_t outsz;
    char *out = reencode_string_len(sb->buf, sb->len,
            output_enc, utf8, &outsz);
    if (out)
      strbuf_attach(sb, out, outsz, outsz + 1);
  }

  free(context.commit_encoding);
  repo_unuse_commit_buffer(r, commit, context.message);
  signature_check_clear(&context.signature_check);
}

static void pp_header(struct pretty_print_context *pp,
          const char *encoding,
          const struct commit *commit,
          const char **msg_p,
          struct strbuf *sb)
{
  int parents_shown = 0;

  for (;;) {
    const char *name, *line = *msg_p;
    int linelen = get_one_line(*msg_p);

    if (!linelen)
      return;
    *msg_p += linelen;

    if (linelen == 1)
      /* End of header */
      return;

    if (pp->fmt == CMIT_FMT_RAW) {
      strbuf_add(sb, line, linelen);
      continue;
    }

    if (starts_with(line, "parent ")) {
      if (linelen != the_hash_algo->hexsz + 8)
        die("bad parent line in commit");
      continue;
    }

    if (!parents_shown) {
      unsigned num = commit_list_count(commit->parents);
      /* with enough slop */
      strbuf_grow(sb, num * (GIT_MAX_HEXSZ + 10) + 20);
      add_merge_info(pp, sb, commit);
      parents_shown = 1;
    }

    /*
     * MEDIUM == DEFAULT shows only author with dates.
     * FULL shows both authors but not dates.
     * FULLER shows both authors and dates.
     */
    if (skip_prefix(line, "author ", &name)) {
      strbuf_grow(sb, linelen + 80);
      pp_user_info(pp, "Author", sb, name, encoding);
    }
    if (skip_prefix(line, "committer ", &name) &&
        (pp->fmt == CMIT_FMT_FULL || pp->fmt == CMIT_FMT_FULLER)) {
      strbuf_grow(sb, linelen + 80);
      pp_user_info(pp, "Commit", sb, name, encoding);
    }
  }
}

void pp_email_subject(struct pretty_print_context *pp,
          const char **msg_p,
          struct strbuf *sb,
          const char *encoding,
          int need_8bit_cte)
{
  static const int max_length = 78; /* per rfc2047 */
  struct strbuf title;

  strbuf_init(&title, 80);
  *msg_p = format_subject(&title, *msg_p,
        pp->preserve_subject ? "\n" : " ");

  strbuf_grow(sb, title.len + 1024);
  fmt_output_email_subject(sb, pp->rev);
  if (pp->encode_email_headers &&
      needs_rfc2047_encoding(title.buf, title.len))
    add_rfc2047(sb, title.buf, title.len,
          encoding, RFC2047_SUBJECT);
  else
    strbuf_add_wrapped_bytes(sb, title.buf, title.len,
           -last_line_length(sb), 1, max_length);
  strbuf_addch(sb, '\n');

  if (need_8bit_cte == 0) {
    int i;
    for (i = 0; i < pp->in_body_headers.nr; i++) {
      if (has_non_ascii(pp->in_body_headers.items[i].string)) {
        need_8bit_cte = 1;
        break;
      }
    }
  }

  if (need_8bit_cte > 0) {
    const char *header_fmt =
      "MIME-Version: 1.0\n"
      "Content-Type: text/plain; charset=%s\n"
      "Content-Transfer-Encoding: 8bit\n";
    strbuf_addf(sb, header_fmt, encoding);
  }
  if (pp->after_subject) {
    strbuf_addstr(sb, pp->after_subject);
  }

  strbuf_addch(sb, '\n');

  if (pp->in_body_headers.nr) {
    int i;
    for (i = 0; i < pp->in_body_headers.nr; i++) {
      strbuf_addstr(sb, pp->in_body_headers.items[i].string);
      free(pp->in_body_headers.items[i].string);
    }
    string_list_clear(&pp->in_body_headers, 0);
    strbuf_addch(sb, '\n');
  }

  strbuf_release(&title);
}

static int pp_utf8_width(const char *start, const char *end)
{
  int width = 0;
  size_t remain = end - start;

  while (remain) {
    int n = utf8_width(&start, &remain);
    if (n < 0 || !start)
      return -1;
    width += n;
  }
  return width;
}

static void strbuf_add_tabexpand(struct strbuf *sb, struct grep_opt *opt,
         enum git_colorbool color, int tabwidth, const char *line,
         int linelen)
{
  const char *tab;

  while ((tab = memchr(line, '\t', linelen)) != NULL) {
    int width = pp_utf8_width(line, tab);

    /*
     * If it wasn't well-formed utf8, or it
     * had characters with badly defined
     * width (control characters etc), just
     * give up on trying to align things.
     */
    if (width < 0)
      break;

    /* Output the data .. */
    append_line_with_color(sb, opt, line, tab - line, color,
               GREP_CONTEXT_BODY,
               GREP_HEADER_FIELD_MAX);

    /* .. and the de-tabified tab */
    strbuf_addchars(sb, ' ', tabwidth - (width % tabwidth));

    /* Skip over the printed part .. */
    linelen -= tab + 1 - line;
    line = tab + 1;
  }

  /*
   * Print out everything after the last tab without
   * worrying about width - there's nothing more to
   * align.
   */
  append_line_with_color(sb, opt, line, linelen, color, GREP_CONTEXT_BODY,
             GREP_HEADER_FIELD_MAX);
}

/*
 * pp_handle_indent() prints out the indentation, and
 * the whole line (without the final newline), after
 * de-tabifying.
 */
static void pp_handle_indent(struct pretty_print_context *pp,
           struct strbuf *sb, int indent,
           const char *line, int linelen)
{
  struct grep_opt *opt = pp->rev ? &pp->rev->grep_filter : NULL;

  strbuf_addchars(sb, ' ', indent);
  if (pp->expand_tabs_in_log)
    strbuf_add_tabexpand(sb, opt, pp->color, pp->expand_tabs_in_log,
             line, linelen);
  else
    append_line_with_color(sb, opt, line, linelen, pp->color,
               GREP_CONTEXT_BODY,
               GREP_HEADER_FIELD_MAX);
}

static int is_mboxrd_from(const char *line, int len)
{
  /*
   * a line matching /^From $/ here would only have len == 4
   * at this point because is_empty_line would've trimmed all
   * trailing space
   */
  return len > 4 && starts_with(line + strspn(line, ">"), "From ");
}

void pp_remainder(struct pretty_print_context *pp,
      const char **msg_p,
      struct strbuf *sb,
      int indent)
{
  struct grep_opt *opt = pp->rev ? &pp->rev->grep_filter : NULL;
  int first = 1;

  for (;;) {
    const char *line = *msg_p;
    int linelen = get_one_line(line);
    *msg_p += linelen;

    if (!linelen)
      break;

    if (is_blank_line(line, &linelen)) {
      if (first)
        continue;
      if (pp->fmt == CMIT_FMT_SHORT)
        break;
    }
    first = 0;

    strbuf_grow(sb, linelen + indent + 20);
    if (indent)
      pp_handle_indent(pp, sb, indent, line, linelen);
    else if (pp->expand_tabs_in_log)
      strbuf_add_tabexpand(sb, opt, pp->color,
               pp->expand_tabs_in_log, line,
               linelen);
    else {
      if (pp->fmt == CMIT_FMT_MBOXRD &&
          is_mboxrd_from(line, linelen))
        strbuf_addch(sb, '>');

      append_line_with_color(sb, opt, line, linelen,
                 pp->color, GREP_CONTEXT_BODY,
                 GREP_HEADER_FIELD_MAX);
    }
    strbuf_addch(sb, '\n');
  }
}

void pretty_print_commit(struct pretty_print_context *pp,
       const struct commit *commit,
       struct strbuf *sb)
{
  unsigned long beginning_of_body;
  int indent = 4;
  const char *msg;
  const char *reencoded;
  const char *encoding;
  int need_8bit_cte = pp->need_8bit_cte;

  if (pp->fmt == CMIT_FMT_USERFORMAT) {
    repo_format_commit_message(the_repository, commit,
             user_format, sb, pp);
    return;
  }

  encoding = get_log_output_encoding();
  msg = reencoded = repo_logmsg_reencode(the_repository, commit, NULL,
                 encoding);

  if (pp->fmt == CMIT_FMT_ONELINE || cmit_fmt_is_mail(pp->fmt))
    indent = 0;

  /*
   * We need to check and emit Content-type: to mark it
   * as 8-bit if we haven't done so.
   */
  if (cmit_fmt_is_mail(pp->fmt) && need_8bit_cte == 0) {
    int i, ch, in_body;

    for (in_body = i = 0; (ch = msg[i]); i++) {
      if (!in_body) {
        /* author could be non 7-bit ASCII but
         * the log may be so; skip over the
         * header part first.
         */
        if (ch == '\n' && msg[i+1] == '\n')
          in_body = 1;
      }
      else if (non_ascii(ch)) {
        need_8bit_cte = 1;
        break;
      }
    }
  }

  pp_header(pp, encoding, commit, &msg, sb);
  if (pp->fmt != CMIT_FMT_ONELINE && !cmit_fmt_is_mail(pp->fmt)) {
    strbuf_addch(sb, '\n');
  }

  /* Skip excess blank lines at the beginning of body, if any... */
  msg = skip_blank_lines(msg);

  /* These formats treat the title line specially. */
  if (pp->fmt == CMIT_FMT_ONELINE) {
    msg = format_subject(sb, msg, " ");
    strbuf_addch(sb, '\n');
  } else if (cmit_fmt_is_mail(pp->fmt))
    pp_email_subject(pp, &msg, sb, encoding, need_8bit_cte);

  beginning_of_body = sb->len;
  if (pp->fmt != CMIT_FMT_ONELINE)
    pp_remainder(pp, &msg, sb, indent);
  strbuf_rtrim(sb);

  /* Make sure there is an EOLN for the non-oneline case */
  if (pp->fmt != CMIT_FMT_ONELINE)
    strbuf_addch(sb, '\n');

  /*
   * The caller may append additional body text in e-mail
   * format.  Make sure we did not strip the blank line
   * between the header and the body.
   */
  if (cmit_fmt_is_mail(pp->fmt) && sb->len <= beginning_of_body)
    strbuf_addch(sb, '\n');

  repo_unuse_commit_buffer(the_repository, commit, reencoded);
}

void pp_commit_easy(enum cmit_fmt fmt, const struct commit *commit,
        struct strbuf *sb)
{
  struct pretty_print_context pp = {0};
  pp.fmt = fmt;
  pretty_print_commit(&pp, commit, sb);
}

Coverage Report

Created: 2026-10-17 07:15