ident.c

   1 /*
   2  * ident.c
   3  *
   4  * create git identifier lines of the form "name <email> date"
   5  *
   6  * Copyright (C) 2005 Linus Torvalds
   7  */
   8 #include "cache.h"
   9 #include "config.h"
  10 #include "date.h"
  11 #include "mailmap.h"
  12
  13 static struct strbuf git_default_name = STRBUF_INIT;
  14 static struct strbuf git_default_email = STRBUF_INIT;
  15 static struct strbuf git_default_date = STRBUF_INIT;
  16 static struct strbuf git_author_name = STRBUF_INIT;
  17 static struct strbuf git_author_email = STRBUF_INIT;
  18 static struct strbuf git_committer_name = STRBUF_INIT;
  19 static struct strbuf git_committer_email = STRBUF_INIT;
  20 static int default_email_is_bogus;
  21 static int default_name_is_bogus;
  22
  23 static int ident_use_config_only;
  24
  25 #define IDENT_NAME_GIVEN 01
  26 #define IDENT_MAIL_GIVEN 02
  27 #define IDENT_ALL_GIVEN (IDENT_NAME_GIVEN|IDENT_MAIL_GIVEN)
  28 static int committer_ident_explicitly_given;
  29 static int author_ident_explicitly_given;
  30 static int ident_config_given;
  31
  32 #ifdef NO_GECOS_IN_PWENT
  33 #define get_gecos(ignored) "&"
  34 #else
  35 #define get_gecos(struct_passwd) ((struct_passwd)->pw_gecos)
  36 #endif
  37
  38 static struct passwd *xgetpwuid_self(int *is_bogus)
  39 {
  40         struct passwd *pw;
  41
  42         errno = 0;
  43         pw = getpwuid(getuid());
  44         if (!pw) {
  45                 static struct passwd fallback;
  46                 fallback.pw_name = "unknown";
  47 #ifndef NO_GECOS_IN_PWENT
  48                 fallback.pw_gecos = "Unknown";
  49 #endif
  50                 pw = &fallback;
  51                 if (is_bogus)
  52                         *is_bogus = 1;
  53         }
  54         return pw;
  55 }
  56
  57 static void copy_gecos(const struct passwd *w, struct strbuf *name)
  58 {
  59         char *src;
  60
  61         /* Traditionally GECOS field had office phone numbers etc, separated
  62          * with commas.  Also & stands for capitalized form of the login name.
  63          */
  64
  65         for (src = get_gecos(w); *src && *src != ','; src++) {
  66                 int ch = *src;
  67                 if (ch != '&')
  68                         strbuf_addch(name, ch);
  69                 else {
  70                         /* Sorry, Mr. McDonald... */
  71                         strbuf_addch(name, toupper(*w->pw_name));
  72                         strbuf_addstr(name, w->pw_name + 1);
  73                 }
  74         }
  75 }
  76
  77 static int add_mailname_host(struct strbuf *buf)
  78 {
  79         FILE *mailname;
  80         struct strbuf mailnamebuf = STRBUF_INIT;
  81
  82         mailname = fopen_or_warn("/etc/mailname", "r");
  83         if (!mailname)
  84                 return -1;
  85
  86         if (strbuf_getline(&mailnamebuf, mailname) == EOF) {
  87                 if (ferror(mailname))
  88                         warning_errno("cannot read /etc/mailname");
  89                 strbuf_release(&mailnamebuf);
  90                 fclose(mailname);
  91                 return -1;
  92         }
  93         /* success! */
  94         strbuf_addbuf(buf, &mailnamebuf);
  95         strbuf_release(&mailnamebuf);
  96         fclose(mailname);
  97         return 0;
  98 }
  99
 100 static int canonical_name(const char *host, struct strbuf *out)
 101 {
 102         int status = -1;
 103
 104 #ifndef NO_IPV6
 105         struct addrinfo hints, *ai;
 106         memset (&hints, '\0', sizeof (hints));
 107         hints.ai_flags = AI_CANONNAME;
 108         if (!getaddrinfo(host, NULL, &hints, &ai)) {
 109                 if (ai && ai->ai_canonname && strchr(ai->ai_canonname, '.')) {
 110                         strbuf_addstr(out, ai->ai_canonname);
 111                         status = 0;
 112                 }
 113                 freeaddrinfo(ai);
 114         }
 115 #else
 116         struct hostent *he = gethostbyname(host);
 117         if (he && strchr(he->h_name, '.')) {
 118                 strbuf_addstr(out, he->h_name);
 119                 status = 0;
 120         }
 121 #endif /* NO_IPV6 */
 122
 123         return status;
 124 }
 125
 126 static void add_domainname(struct strbuf *out, int *is_bogus)
 127 {
 128         char buf[HOST_NAME_MAX + 1];
 129
 130         if (xgethostname(buf, sizeof(buf))) {
 131                 warning_errno("cannot get host name");
 132                 strbuf_addstr(out, "(none)");
 133                 *is_bogus = 1;
 134                 return;
 135         }
 136         if (strchr(buf, '.'))
 137                 strbuf_addstr(out, buf);
 138         else if (canonical_name(buf, out) < 0) {
 139                 strbuf_addf(out, "%s.(none)", buf);
 140                 *is_bogus = 1;
 141         }
 142 }
 143
 144 static void copy_email(const struct passwd *pw, struct strbuf *email,
 145                        int *is_bogus)
 146 {
 147         /*
 148          * Make up a fake email address
 149          * (name + '@' + hostname [+ '.' + domainname])
 150          */
 151         strbuf_addstr(email, pw->pw_name);
 152         strbuf_addch(email, '@');
 153
 154         if (!add_mailname_host(email))
 155                 return; /* read from "/etc/mailname" (Debian) */
 156         add_domainname(email, is_bogus);
 157 }
 158
 159 const char *ident_default_name(void)
 160 {
 161         if (!(ident_config_given & IDENT_NAME_GIVEN) && !git_default_name.len) {
 162                 copy_gecos(xgetpwuid_self(&default_name_is_bogus), &git_default_name);
 163                 strbuf_trim(&git_default_name);
 164         }
 165         return git_default_name.buf;
 166 }
 167
 168 const char *ident_default_email(void)
 169 {
 170         if (!(ident_config_given & IDENT_MAIL_GIVEN) && !git_default_email.len) {
 171                 const char *email = getenv("EMAIL");
 172
 173                 if (email && email[0]) {
 174                         strbuf_addstr(&git_default_email, email);
 175                         committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 176                         author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 177                 } else if ((email = query_user_email()) && email[0]) {
 178                         strbuf_addstr(&git_default_email, email);
 179                         free((char *)email);
 180                 } else
 181                         copy_email(xgetpwuid_self(&default_email_is_bogus),
 182                                    &git_default_email, &default_email_is_bogus);
 183                 strbuf_trim(&git_default_email);
 184         }
 185         return git_default_email.buf;
 186 }
 187
 188 static const char *ident_default_date(void)
 189 {
 190         if (!git_default_date.len)
 191                 datestamp(&git_default_date);
 192         return git_default_date.buf;
 193 }
 194
 195 void reset_ident_date(void)
 196 {
 197         strbuf_reset(&git_default_date);
 198 }
 199
 200 static int crud(unsigned char c)
 201 {
 202         return  c <= 32  ||
 203                 c == '.' ||
 204                 c == ',' ||
 205                 c == ':' ||
 206                 c == ';' ||
 207                 c == '<' ||
 208                 c == '>' ||
 209                 c == '"' ||
 210                 c == '\\' ||
 211                 c == '\'';
 212 }
 213
 214 static int has_non_crud(const char *str)
 215 {
 216         for (; *str; str++) {
 217                 if (!crud(*str))
 218                         return 1;
 219         }
 220         return 0;
 221 }
 222
 223 /*
 224  * Copy over a string to the destination, but avoid special
 225  * characters ('\n', '<' and '>') and remove crud at the end
 226  */
 227 static void strbuf_addstr_without_crud(struct strbuf *sb, const char *src)
 228 {
 229         size_t i, len;
 230         unsigned char c;
 231
 232         /* Remove crud from the beginning.. */
 233         while ((c = *src) != 0) {
 234                 if (!crud(c))
 235                         break;
 236                 src++;
 237         }
 238
 239         /* Remove crud from the end.. */
 240         len = strlen(src);
 241         while (len > 0) {
 242                 c = src[len-1];
 243                 if (!crud(c))
 244                         break;
 245                 --len;
 246         }
 247
 248         /*
 249          * Copy the rest to the buffer, but avoid the special
 250          * characters '\n' '<' and '>' that act as delimiters on
 251          * an identification line. We can only remove crud, never add it,
 252          * so 'len' is our maximum.
 253          */
 254         strbuf_grow(sb, len);
 255         for (i = 0; i < len; i++) {
 256                 c = *src++;
 257                 switch (c) {
 258                 case '\n': case '<': case '>':
 259                         continue;
 260                 }
 261                 sb->buf[sb->len++] = c;
 262         }
 263         sb->buf[sb->len] = '\0';
 264 }
 265
 266 /*
 267  * Reverse of fmt_ident(); given an ident line, split the fields
 268  * to allow the caller to parse it.
 269  * Signal a success by returning 0, but date/tz fields of the result
 270  * can still be NULL if the input line only has the name/email part
 271  * (e.g. reading from a reflog entry).
 272  */
 273 int split_ident_line(struct ident_split *split, const char *line, int len)
 274 {
 275         const char *cp;
 276         size_t span;
 277         int status = -1;
 278
 279         memset(split, 0, sizeof(*split));
 280
 281         split->name_begin = line;
 282         for (cp = line; *cp && cp < line + len; cp++)
 283                 if (*cp == '<') {
 284                         split->mail_begin = cp + 1;
 285                         break;
 286                 }
 287         if (!split->mail_begin)
 288                 return status;
 289
 290         for (cp = split->mail_begin - 2; line <= cp; cp--)
 291                 if (!isspace(*cp)) {
 292                         split->name_end = cp + 1;
 293                         break;
 294                 }
 295         if (!split->name_end) {
 296                 /* no human readable name */
 297                 split->name_end = split->name_begin;
 298         }
 299
 300         for (cp = split->mail_begin; cp < line + len; cp++)
 301                 if (*cp == '>') {
 302                         split->mail_end = cp;
 303                         break;
 304                 }
 305         if (!split->mail_end)
 306                 return status;
 307
 308         /*
 309          * Look from the end-of-line to find the trailing ">" of the mail
 310          * address, even though we should already know it as split->mail_end.
 311          * This can help in cases of broken idents with an extra ">" somewhere
 312          * in the email address.  Note that we are assuming the timestamp will
 313          * never have a ">" in it.
 314          *
 315          * Note that we will always find some ">" before going off the front of
 316          * the string, because will always hit the split->mail_end closing
 317          * bracket.
 318          */
 319         for (cp = line + len - 1; *cp != '>'; cp--)
 320                 ;
 321
 322         for (cp = cp + 1; cp < line + len && isspace(*cp); cp++)
 323                 ;
 324         if (line + len <= cp)
 325                 goto person_only;
 326         split->date_begin = cp;
 327         span = strspn(cp, "0123456789");
 328         if (!span)
 329                 goto person_only;
 330         split->date_end = split->date_begin + span;
 331         for (cp = split->date_end; cp < line + len && isspace(*cp); cp++)
 332                 ;
 333         if (line + len <= cp || (*cp != '+' && *cp != '-'))
 334                 goto person_only;
 335         split->tz_begin = cp;
 336         span = strspn(cp + 1, "0123456789");
 337         if (!span)
 338                 goto person_only;
 339         split->tz_end = split->tz_begin + 1 + span;
 340         return 0;
 341
 342 person_only:
 343         split->date_begin = NULL;
 344         split->date_end = NULL;
 345         split->tz_begin = NULL;
 346         split->tz_end = NULL;
 347         return 0;
 348 }
 349
 350 /*
 351  * Returns the difference between the new and old length of the ident line.
 352  */
 353 static ssize_t rewrite_ident_line(const char *person, size_t len,
 354                                    struct strbuf *buf,
 355                                    struct string_list *mailmap)
 356 {
 357         size_t namelen, maillen;
 358         const char *name;
 359         const char *mail;
 360         struct ident_split ident;
 361
 362         if (split_ident_line(&ident, person, len))
 363                 return 0;
 364
 365         mail = ident.mail_begin;
 366         maillen = ident.mail_end - ident.mail_begin;
 367         name = ident.name_begin;
 368         namelen = ident.name_end - ident.name_begin;
 369
 370         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
 371                 struct strbuf namemail = STRBUF_INIT;
 372                 size_t newlen;
 373
 374                 strbuf_addf(&namemail, "%.*s <%.*s>",
 375                             (int)namelen, name, (int)maillen, mail);
 376
 377                 strbuf_splice(buf, ident.name_begin - buf->buf,
 378                               ident.mail_end - ident.name_begin + 1,
 379                               namemail.buf, namemail.len);
 380                 newlen = namemail.len;
 381
 382                 strbuf_release(&namemail);
 383
 384                 return newlen - (ident.mail_end - ident.name_begin);
 385         }
 386
 387         return 0;
 388 }
 389
 390 void apply_mailmap_to_header(struct strbuf *buf, const char **header,
 391                                struct string_list *mailmap)
 392 {
 393         size_t buf_offset = 0;
 394
 395         if (!mailmap)
 396                 return;
 397
 398         for (;;) {
 399                 const char *person, *line;
 400                 size_t i;
 401                 int found_header = 0;
 402
 403                 line = buf->buf + buf_offset;
 404                 if (!*line || *line == '\n')
 405                         return; /* End of headers */
 406
 407                 for (i = 0; header[i]; i++)
 408                         if (skip_prefix(line, header[i], &person)) {
 409                                 const char *endp = strchrnul(person, '\n');
 410                                 found_header = 1;
 411                                 buf_offset += endp - line;
 412                                 buf_offset += rewrite_ident_line(person, endp - person, buf, mailmap);
 413                                 break;
 414                         }
 415
 416                 if (!found_header) {
 417                         buf_offset = strchrnul(line, '\n') - buf->buf;
 418                         if (buf->buf[buf_offset] == '\n')
 419                                 buf_offset++;
 420                 }
 421         }
 422 }
 423
 424 static void ident_env_hint(enum want_ident whose_ident)
 425 {
 426         switch (whose_ident) {
 427         case WANT_AUTHOR_IDENT:
 428                 fputs(_("Author identity unknown\n"), stderr);
 429                 break;
 430         case WANT_COMMITTER_IDENT:
 431                 fputs(_("Committer identity unknown\n"), stderr);
 432                 break;
 433         default:
 434                 break;
 435         }
 436
 437         fputs(_("\n"
 438                 "*** Please tell me who you are.\n"
 439                 "\n"
 440                 "Run\n"
 441                 "\n"
 442                 "  git config --global user.email \"you@example.com\"\n"
 443                 "  git config --global user.name \"Your Name\"\n"
 444                 "\n"
 445                 "to set your account\'s default identity.\n"
 446                 "Omit --global to set the identity only in this repository.\n"
 447                 "\n"), stderr);
 448 }
 449
 450 const char *fmt_ident(const char *name, const char *email,
 451                       enum want_ident whose_ident, const char *date_str, int flag)
 452 {
 453         static int index;
 454         static struct strbuf ident_pool[2] = { STRBUF_INIT, STRBUF_INIT };
 455         int strict = (flag & IDENT_STRICT);
 456         int want_date = !(flag & IDENT_NO_DATE);
 457         int want_name = !(flag & IDENT_NO_NAME);
 458
 459         struct strbuf *ident = &ident_pool[index];
 460         index = (index + 1) % ARRAY_SIZE(ident_pool);
 461
 462         if (!email) {
 463                 if (whose_ident == WANT_AUTHOR_IDENT && git_author_email.len)
 464                         email = git_author_email.buf;
 465                 else if (whose_ident == WANT_COMMITTER_IDENT && git_committer_email.len)
 466                         email = git_committer_email.buf;
 467         }
 468         if (!email) {
 469                 if (strict && ident_use_config_only
 470                     && !(ident_config_given & IDENT_MAIL_GIVEN)) {
 471                         ident_env_hint(whose_ident);
 472                         die(_("no email was given and auto-detection is disabled"));
 473                 }
 474                 email = ident_default_email();
 475                 if (strict && default_email_is_bogus) {
 476                         ident_env_hint(whose_ident);
 477                         die(_("unable to auto-detect email address (got '%s')"), email);
 478                 }
 479         }
 480
 481         if (want_name) {
 482                 int using_default = 0;
 483                 if (!name) {
 484                         if (whose_ident == WANT_AUTHOR_IDENT && git_author_name.len)
 485                                 name = git_author_name.buf;
 486                         else if (whose_ident == WANT_COMMITTER_IDENT &&
 487                                         git_committer_name.len)
 488                                 name = git_committer_name.buf;
 489                 }
 490                 if (!name) {
 491                         if (strict && ident_use_config_only
 492                             && !(ident_config_given & IDENT_NAME_GIVEN)) {
 493                                 ident_env_hint(whose_ident);
 494                                 die(_("no name was given and auto-detection is disabled"));
 495                         }
 496                         name = ident_default_name();
 497                         using_default = 1;
 498                         if (strict && default_name_is_bogus) {
 499                                 ident_env_hint(whose_ident);
 500                                 die(_("unable to auto-detect name (got '%s')"), name);
 501                         }
 502                 }
 503                 if (!*name) {
 504                         struct passwd *pw;
 505                         if (strict) {
 506                                 if (using_default)
 507                                         ident_env_hint(whose_ident);
 508                                 die(_("empty ident name (for <%s>) not allowed"), email);
 509                         }
 510                         pw = xgetpwuid_self(NULL);
 511                         name = pw->pw_name;
 512                 }
 513                 if (strict && !has_non_crud(name))
 514                         die(_("name consists only of disallowed characters: %s"), name);
 515         }
 516
 517         strbuf_reset(ident);
 518         if (want_name) {
 519                 strbuf_addstr_without_crud(ident, name);
 520                 strbuf_addstr(ident, " <");
 521         }
 522         strbuf_addstr_without_crud(ident, email);
 523         if (want_name)
 524                 strbuf_addch(ident, '>');
 525         if (want_date) {
 526                 strbuf_addch(ident, ' ');
 527                 if (date_str && date_str[0]) {
 528                         if (parse_date(date_str, ident) < 0)
 529                                 die(_("invalid date format: %s"), date_str);
 530                 }
 531                 else
 532                         strbuf_addstr(ident, ident_default_date());
 533         }
 534
 535         return ident->buf;
 536 }
 537
 538 const char *fmt_name(enum want_ident whose_ident)
 539 {
 540         char *name = NULL;
 541         char *email = NULL;
 542
 543         switch (whose_ident) {
 544         case WANT_BLANK_IDENT:
 545                 break;
 546         case WANT_AUTHOR_IDENT:
 547                 name = getenv("GIT_AUTHOR_NAME");
 548                 email = getenv("GIT_AUTHOR_EMAIL");
 549                 break;
 550         case WANT_COMMITTER_IDENT:
 551                 name = getenv("GIT_COMMITTER_NAME");
 552                 email = getenv("GIT_COMMITTER_EMAIL");
 553                 break;
 554         }
 555         return fmt_ident(name, email, whose_ident, NULL,
 556                         IDENT_STRICT | IDENT_NO_DATE);
 557 }
 558
 559 const char *git_author_info(int flag)
 560 {
 561         if (getenv("GIT_AUTHOR_NAME"))
 562                 author_ident_explicitly_given |= IDENT_NAME_GIVEN;
 563         if (getenv("GIT_AUTHOR_EMAIL"))
 564                 author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 565         return fmt_ident(getenv("GIT_AUTHOR_NAME"),
 566                          getenv("GIT_AUTHOR_EMAIL"),
 567                          WANT_AUTHOR_IDENT,
 568                          getenv("GIT_AUTHOR_DATE"),
 569                          flag);
 570 }
 571
 572 const char *git_committer_info(int flag)
 573 {
 574         if (getenv("GIT_COMMITTER_NAME"))
 575                 committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
 576         if (getenv("GIT_COMMITTER_EMAIL"))
 577                 committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 578         return fmt_ident(getenv("GIT_COMMITTER_NAME"),
 579                          getenv("GIT_COMMITTER_EMAIL"),
 580                          WANT_COMMITTER_IDENT,
 581                          getenv("GIT_COMMITTER_DATE"),
 582                          flag);
 583 }
 584
 585 static int ident_is_sufficient(int user_ident_explicitly_given)
 586 {
 587 #ifndef WINDOWS
 588         return (user_ident_explicitly_given & IDENT_MAIL_GIVEN);
 589 #else
 590         return (user_ident_explicitly_given == IDENT_ALL_GIVEN);
 591 #endif
 592 }
 593
 594 int committer_ident_sufficiently_given(void)
 595 {
 596         return ident_is_sufficient(committer_ident_explicitly_given);
 597 }
 598
 599 int author_ident_sufficiently_given(void)
 600 {
 601         return ident_is_sufficient(author_ident_explicitly_given);
 602 }
 603
 604 static int set_ident(const char *var, const char *value)
 605 {
 606         if (!strcmp(var, "author.name")) {
 607                 if (!value)
 608                         return config_error_nonbool(var);
 609                 strbuf_reset(&git_author_name);
 610                 strbuf_addstr(&git_author_name, value);
 611                 author_ident_explicitly_given |= IDENT_NAME_GIVEN;
 612                 ident_config_given |= IDENT_NAME_GIVEN;
 613                 return 0;
 614         }
 615
 616         if (!strcmp(var, "author.email")) {
 617                 if (!value)
 618                         return config_error_nonbool(var);
 619                 strbuf_reset(&git_author_email);
 620                 strbuf_addstr(&git_author_email, value);
 621                 author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 622                 ident_config_given |= IDENT_MAIL_GIVEN;
 623                 return 0;
 624         }
 625
 626         if (!strcmp(var, "committer.name")) {
 627                 if (!value)
 628                         return config_error_nonbool(var);
 629                 strbuf_reset(&git_committer_name);
 630                 strbuf_addstr(&git_committer_name, value);
 631                 committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
 632                 ident_config_given |= IDENT_NAME_GIVEN;
 633                 return 0;
 634         }
 635
 636         if (!strcmp(var, "committer.email")) {
 637                 if (!value)
 638                         return config_error_nonbool(var);
 639                 strbuf_reset(&git_committer_email);
 640                 strbuf_addstr(&git_committer_email, value);
 641                 committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 642                 ident_config_given |= IDENT_MAIL_GIVEN;
 643                 return 0;
 644         }
 645
 646         if (!strcmp(var, "user.name")) {
 647                 if (!value)
 648                         return config_error_nonbool(var);
 649                 strbuf_reset(&git_default_name);
 650                 strbuf_addstr(&git_default_name, value);
 651                 committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
 652                 author_ident_explicitly_given |= IDENT_NAME_GIVEN;
 653                 ident_config_given |= IDENT_NAME_GIVEN;
 654                 return 0;
 655         }
 656
 657         if (!strcmp(var, "user.email")) {
 658                 if (!value)
 659                         return config_error_nonbool(var);
 660                 strbuf_reset(&git_default_email);
 661                 strbuf_addstr(&git_default_email, value);
 662                 committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 663                 author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 664                 ident_config_given |= IDENT_MAIL_GIVEN;
 665                 return 0;
 666         }
 667
 668         return 0;
 669 }
 670
 671 int git_ident_config(const char *var, const char *value, void *data)
 672 {
 673         if (!strcmp(var, "user.useconfigonly")) {
 674                 ident_use_config_only = git_config_bool(var, value);
 675                 return 0;
 676         }
 677
 678         return set_ident(var, value);
 679 }
 680
 681 static void set_env_if(const char *key, const char *value, int *given, int bit)
 682 {
 683         if ((*given & bit) || getenv(key))
 684                 return; /* nothing to do */
 685         setenv(key, value, 0);
 686         *given |= bit;
 687 }
 688
 689 void prepare_fallback_ident(const char *name, const char *email)
 690 {
 691         set_env_if("GIT_AUTHOR_NAME", name,
 692                    &author_ident_explicitly_given, IDENT_NAME_GIVEN);
 693         set_env_if("GIT_AUTHOR_EMAIL", email,
 694                    &author_ident_explicitly_given, IDENT_MAIL_GIVEN);
 695         set_env_if("GIT_COMMITTER_NAME", name,
 696                    &committer_ident_explicitly_given, IDENT_NAME_GIVEN);
 697         set_env_if("GIT_COMMITTER_EMAIL", email,
 698                    &committer_ident_explicitly_given, IDENT_MAIL_GIVEN);
 699 }
 700
 701 static int buf_cmp(const char *a_begin, const char *a_end,
 702                    const char *b_begin, const char *b_end)
 703 {
 704         int a_len = a_end - a_begin;
 705         int b_len = b_end - b_begin;
 706         int min = a_len < b_len ? a_len : b_len;
 707         int cmp;
 708
 709         cmp = memcmp(a_begin, b_begin, min);
 710         if (cmp)
 711                 return cmp;
 712
 713         return a_len - b_len;
 714 }
 715
 716 int ident_cmp(const struct ident_split *a,
 717               const struct ident_split *b)
 718 {
 719         int cmp;
 720
 721         cmp = buf_cmp(a->mail_begin, a->mail_end,
 722                       b->mail_begin, b->mail_end);
 723         if (cmp)
 724                 return cmp;
 725
 726         return buf_cmp(a->name_begin, a->name_end,
 727                        b->name_begin, b->name_end);
 728 }