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 "git-compat-util.h"
   9 #include "ident.h"
  10 #include "config.h"
  11 #include "date.h"
  12 #include "gettext.h"
  13 #include "mailmap.h"
  14 #include "strbuf.h"
  15
  16 static struct strbuf git_default_name = STRBUF_INIT;
  17 static struct strbuf git_default_email = STRBUF_INIT;
  18 static struct strbuf git_default_date = STRBUF_INIT;
  19 static struct strbuf git_author_name = STRBUF_INIT;
  20 static struct strbuf git_author_email = STRBUF_INIT;
  21 static struct strbuf git_committer_name = STRBUF_INIT;
  22 static struct strbuf git_committer_email = STRBUF_INIT;
  23 static int default_email_is_bogus;
  24 static int default_name_is_bogus;
  25
  26 static int ident_use_config_only;
  27
  28 #define IDENT_NAME_GIVEN 01
  29 #define IDENT_MAIL_GIVEN 02
  30 #define IDENT_ALL_GIVEN (IDENT_NAME_GIVEN|IDENT_MAIL_GIVEN)
  31 static int committer_ident_explicitly_given;
  32 static int author_ident_explicitly_given;
  33 static int ident_config_given;
  34
  35 #ifdef NO_GECOS_IN_PWENT
  36 #define get_gecos(ignored) "&"
  37 #else
  38 #define get_gecos(struct_passwd) ((struct_passwd)->pw_gecos)
  39 #endif
  40
  41 static struct passwd *xgetpwuid_self(int *is_bogus)
  42 {
  43         struct passwd *pw;
  44
  45         errno = 0;
  46         pw = getpwuid(getuid());
  47         if (!pw) {
  48                 static struct passwd fallback;
  49                 fallback.pw_name = "unknown";
  50 #ifndef NO_GECOS_IN_PWENT
  51                 fallback.pw_gecos = "Unknown";
  52 #endif
  53                 pw = &fallback;
  54                 if (is_bogus)
  55                         *is_bogus = 1;
  56         }
  57         return pw;
  58 }
  59
  60 static void copy_gecos(const struct passwd *w, struct strbuf *name)
  61 {
  62         char *src;
  63
  64         /* Traditionally GECOS field had office phone numbers etc, separated
  65          * with commas.  Also & stands for capitalized form of the login name.
  66          */
  67
  68         for (src = get_gecos(w); *src && *src != ','; src++) {
  69                 int ch = *src;
  70                 if (ch != '&')
  71                         strbuf_addch(name, ch);
  72                 else {
  73                         /* Sorry, Mr. McDonald... */
  74                         strbuf_addch(name, toupper(*w->pw_name));
  75                         strbuf_addstr(name, w->pw_name + 1);
  76                 }
  77         }
  78 }
  79
  80 static int add_mailname_host(struct strbuf *buf)
  81 {
  82         FILE *mailname;
  83         struct strbuf mailnamebuf = STRBUF_INIT;
  84
  85         mailname = fopen_or_warn("/etc/mailname", "r");
  86         if (!mailname)
  87                 return -1;
  88
  89         if (strbuf_getline(&mailnamebuf, mailname) == EOF) {
  90                 if (ferror(mailname))
  91                         warning_errno("cannot read /etc/mailname");
  92                 strbuf_release(&mailnamebuf);
  93                 fclose(mailname);
  94                 return -1;
  95         }
  96         /* success! */
  97         strbuf_addbuf(buf, &mailnamebuf);
  98         strbuf_release(&mailnamebuf);
  99         fclose(mailname);
 100         return 0;
 101 }
 102
 103 static int canonical_name(const char *host, struct strbuf *out)
 104 {
 105         int status = -1;
 106
 107 #ifndef NO_IPV6
 108         struct addrinfo hints, *ai;
 109         memset (&hints, '\0', sizeof (hints));
 110         hints.ai_flags = AI_CANONNAME;
 111         if (!getaddrinfo(host, NULL, &hints, &ai)) {
 112                 if (ai && ai->ai_canonname && strchr(ai->ai_canonname, '.')) {
 113                         strbuf_addstr(out, ai->ai_canonname);
 114                         status = 0;
 115                 }
 116                 freeaddrinfo(ai);
 117         }
 118 #else
 119         struct hostent *he = gethostbyname(host);
 120         if (he && strchr(he->h_name, '.')) {
 121                 strbuf_addstr(out, he->h_name);
 122                 status = 0;
 123         }
 124 #endif /* NO_IPV6 */
 125
 126         return status;
 127 }
 128
 129 static void add_domainname(struct strbuf *out, int *is_bogus)
 130 {
 131         char buf[HOST_NAME_MAX + 1];
 132
 133         if (xgethostname(buf, sizeof(buf))) {
 134                 warning_errno("cannot get host name");
 135                 strbuf_addstr(out, "(none)");
 136                 *is_bogus = 1;
 137                 return;
 138         }
 139         if (strchr(buf, '.'))
 140                 strbuf_addstr(out, buf);
 141         else if (canonical_name(buf, out) < 0) {
 142                 strbuf_addf(out, "%s.(none)", buf);
 143                 *is_bogus = 1;
 144         }
 145 }
 146
 147 static void copy_email(const struct passwd *pw, struct strbuf *email,
 148                        int *is_bogus)
 149 {
 150         /*
 151          * Make up a fake email address
 152          * (name + '@' + hostname [+ '.' + domainname])
 153          */
 154         strbuf_addstr(email, pw->pw_name);
 155         strbuf_addch(email, '@');
 156
 157         if (!add_mailname_host(email))
 158                 return; /* read from "/etc/mailname" (Debian) */
 159         add_domainname(email, is_bogus);
 160 }
 161
 162 const char *ident_default_name(void)
 163 {
 164         if (!(ident_config_given & IDENT_NAME_GIVEN) && !git_default_name.len) {
 165                 copy_gecos(xgetpwuid_self(&default_name_is_bogus), &git_default_name);
 166                 strbuf_trim(&git_default_name);
 167         }
 168         return git_default_name.buf;
 169 }
 170
 171 const char *ident_default_email(void)
 172 {
 173         if (!(ident_config_given & IDENT_MAIL_GIVEN) && !git_default_email.len) {
 174                 const char *email = getenv("EMAIL");
 175
 176                 if (email && email[0]) {
 177                         strbuf_addstr(&git_default_email, email);
 178                         committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 179                         author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 180                 } else if ((email = query_user_email()) && email[0]) {
 181                         strbuf_addstr(&git_default_email, email);
 182                         free((char *)email);
 183                 } else
 184                         copy_email(xgetpwuid_self(&default_email_is_bogus),
 185                                    &git_default_email, &default_email_is_bogus);
 186                 strbuf_trim(&git_default_email);
 187         }
 188         return git_default_email.buf;
 189 }
 190
 191 static const char *ident_default_date(void)
 192 {
 193         if (!git_default_date.len)
 194                 datestamp(&git_default_date);
 195         return git_default_date.buf;
 196 }
 197
 198 void reset_ident_date(void)
 199 {
 200         strbuf_reset(&git_default_date);
 201 }
 202
 203 static int crud(unsigned char c)
 204 {
 205         return  c <= 32  ||
 206                 c == '.' ||
 207                 c == ',' ||
 208                 c == ':' ||
 209                 c == ';' ||
 210                 c == '<' ||
 211                 c == '>' ||
 212                 c == '"' ||
 213                 c == '\\' ||
 214                 c == '\'';
 215 }
 216
 217 static int has_non_crud(const char *str)
 218 {
 219         for (; *str; str++) {
 220                 if (!crud(*str))
 221                         return 1;
 222         }
 223         return 0;
 224 }
 225
 226 /*
 227  * Copy over a string to the destination, but avoid special
 228  * characters ('\n', '<' and '>') and remove crud at the end
 229  */
 230 static void strbuf_addstr_without_crud(struct strbuf *sb, const char *src)
 231 {
 232         size_t i, len;
 233         unsigned char c;
 234
 235         /* Remove crud from the beginning.. */
 236         while ((c = *src) != 0) {
 237                 if (!crud(c))
 238                         break;
 239                 src++;
 240         }
 241
 242         /* Remove crud from the end.. */
 243         len = strlen(src);
 244         while (len > 0) {
 245                 c = src[len-1];
 246                 if (!crud(c))
 247                         break;
 248                 --len;
 249         }
 250
 251         /*
 252          * Copy the rest to the buffer, but avoid the special
 253          * characters '\n' '<' and '>' that act as delimiters on
 254          * an identification line. We can only remove crud, never add it,
 255          * so 'len' is our maximum.
 256          */
 257         strbuf_grow(sb, len);
 258         for (i = 0; i < len; i++) {
 259                 c = *src++;
 260                 switch (c) {
 261                 case '\n': case '<': case '>':
 262                         continue;
 263                 }
 264                 sb->buf[sb->len++] = c;
 265         }
 266         sb->buf[sb->len] = '\0';
 267 }
 268
 269 /*
 270  * Reverse of fmt_ident(); given an ident line, split the fields
 271  * to allow the caller to parse it.
 272  * Signal a success by returning 0, but date/tz fields of the result
 273  * can still be NULL if the input line only has the name/email part
 274  * (e.g. reading from a reflog entry).
 275  */
 276 int split_ident_line(struct ident_split *split, const char *line, int len)
 277 {
 278         const char *cp;
 279         size_t span;
 280         int status = -1;
 281
 282         memset(split, 0, sizeof(*split));
 283
 284         split->name_begin = line;
 285         for (cp = line; *cp && cp < line + len; cp++)
 286                 if (*cp == '<') {
 287                         split->mail_begin = cp + 1;
 288                         break;
 289                 }
 290         if (!split->mail_begin)
 291                 return status;
 292
 293         for (cp = split->mail_begin - 2; line <= cp; cp--)
 294                 if (!isspace(*cp)) {
 295                         split->name_end = cp + 1;
 296                         break;
 297                 }
 298         if (!split->name_end) {
 299                 /* no human readable name */
 300                 split->name_end = split->name_begin;
 301         }
 302
 303         for (cp = split->mail_begin; cp < line + len; cp++)
 304                 if (*cp == '>') {
 305                         split->mail_end = cp;
 306                         break;
 307                 }
 308         if (!split->mail_end)
 309                 return status;
 310
 311         /*
 312          * Look from the end-of-line to find the trailing ">" of the mail
 313          * address, even though we should already know it as split->mail_end.
 314          * This can help in cases of broken idents with an extra ">" somewhere
 315          * in the email address.  Note that we are assuming the timestamp will
 316          * never have a ">" in it.
 317          *
 318          * Note that we will always find some ">" before going off the front of
 319          * the string, because will always hit the split->mail_end closing
 320          * bracket.
 321          */
 322         for (cp = line + len - 1; *cp != '>'; cp--)
 323                 ;
 324
 325         for (cp = cp + 1; cp < line + len && isspace(*cp); cp++)
 326                 ;
 327         if (line + len <= cp)
 328                 goto person_only;
 329         split->date_begin = cp;
 330         span = strspn(cp, "0123456789");
 331         if (!span)
 332                 goto person_only;
 333         split->date_end = split->date_begin + span;
 334         for (cp = split->date_end; cp < line + len && isspace(*cp); cp++)
 335                 ;
 336         if (line + len <= cp || (*cp != '+' && *cp != '-'))
 337                 goto person_only;
 338         split->tz_begin = cp;
 339         span = strspn(cp + 1, "0123456789");
 340         if (!span)
 341                 goto person_only;
 342         split->tz_end = split->tz_begin + 1 + span;
 343         return 0;
 344
 345 person_only:
 346         split->date_begin = NULL;
 347         split->date_end = NULL;
 348         split->tz_begin = NULL;
 349         split->tz_end = NULL;
 350         return 0;
 351 }
 352
 353 /*
 354  * Returns the difference between the new and old length of the ident line.
 355  */
 356 static ssize_t rewrite_ident_line(const char *person, size_t len,
 357                                    struct strbuf *buf,
 358                                    struct string_list *mailmap)
 359 {
 360         size_t namelen, maillen;
 361         const char *name;
 362         const char *mail;
 363         struct ident_split ident;
 364
 365         if (split_ident_line(&ident, person, len))
 366                 return 0;
 367
 368         mail = ident.mail_begin;
 369         maillen = ident.mail_end - ident.mail_begin;
 370         name = ident.name_begin;
 371         namelen = ident.name_end - ident.name_begin;
 372
 373         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
 374                 struct strbuf namemail = STRBUF_INIT;
 375                 size_t newlen;
 376
 377                 strbuf_addf(&namemail, "%.*s <%.*s>",
 378                             (int)namelen, name, (int)maillen, mail);
 379
 380                 strbuf_splice(buf, ident.name_begin - buf->buf,
 381                               ident.mail_end - ident.name_begin + 1,
 382                               namemail.buf, namemail.len);
 383                 newlen = namemail.len;
 384
 385                 strbuf_release(&namemail);
 386
 387                 return newlen - (ident.mail_end - ident.name_begin);
 388         }
 389
 390         return 0;
 391 }
 392
 393 void apply_mailmap_to_header(struct strbuf *buf, const char **header,
 394                                struct string_list *mailmap)
 395 {
 396         size_t buf_offset = 0;
 397
 398         if (!mailmap)
 399                 return;
 400
 401         for (;;) {
 402                 const char *person, *line;
 403                 size_t i;
 404                 int found_header = 0;
 405
 406                 line = buf->buf + buf_offset;
 407                 if (!*line || *line == '\n')
 408                         return; /* End of headers */
 409
 410                 for (i = 0; header[i]; i++)
 411                         if (skip_prefix(line, header[i], &person)) {
 412                                 const char *endp = strchrnul(person, '\n');
 413                                 found_header = 1;
 414                                 buf_offset += endp - line;
 415                                 buf_offset += rewrite_ident_line(person, endp - person, buf, mailmap);
 416                                 break;
 417                         }
 418
 419                 if (!found_header) {
 420                         buf_offset = strchrnul(line, '\n') - buf->buf;
 421                         if (buf->buf[buf_offset] == '\n')
 422                                 buf_offset++;
 423                 }
 424         }
 425 }
 426
 427 static void ident_env_hint(enum want_ident whose_ident)
 428 {
 429         switch (whose_ident) {
 430         case WANT_AUTHOR_IDENT:
 431                 fputs(_("Author identity unknown\n"), stderr);
 432                 break;
 433         case WANT_COMMITTER_IDENT:
 434                 fputs(_("Committer identity unknown\n"), stderr);
 435                 break;
 436         default:
 437                 break;
 438         }
 439
 440         fputs(_("\n"
 441                 "*** Please tell me who you are.\n"
 442                 "\n"
 443                 "Run\n"
 444                 "\n"
 445                 "  git config --global user.email \"you@example.com\"\n"
 446                 "  git config --global user.name \"Your Name\"\n"
 447                 "\n"
 448                 "to set your account\'s default identity.\n"
 449                 "Omit --global to set the identity only in this repository.\n"
 450                 "\n"), stderr);
 451 }
 452
 453 const char *fmt_ident(const char *name, const char *email,
 454                       enum want_ident whose_ident, const char *date_str, int flag)
 455 {
 456         static int index;
 457         static struct strbuf ident_pool[2] = { STRBUF_INIT, STRBUF_INIT };
 458         int strict = (flag & IDENT_STRICT);
 459         int want_date = !(flag & IDENT_NO_DATE);
 460         int want_name = !(flag & IDENT_NO_NAME);
 461
 462         struct strbuf *ident = &ident_pool[index];
 463         index = (index + 1) % ARRAY_SIZE(ident_pool);
 464
 465         if (!email) {
 466                 if (whose_ident == WANT_AUTHOR_IDENT && git_author_email.len)
 467                         email = git_author_email.buf;
 468                 else if (whose_ident == WANT_COMMITTER_IDENT && git_committer_email.len)
 469                         email = git_committer_email.buf;
 470         }
 471         if (!email) {
 472                 if (strict && ident_use_config_only
 473                     && !(ident_config_given & IDENT_MAIL_GIVEN)) {
 474                         ident_env_hint(whose_ident);
 475                         die(_("no email was given and auto-detection is disabled"));
 476                 }
 477                 email = ident_default_email();
 478                 if (strict && default_email_is_bogus) {
 479                         ident_env_hint(whose_ident);
 480                         die(_("unable to auto-detect email address (got '%s')"), email);
 481                 }
 482         }
 483
 484         if (want_name) {
 485                 int using_default = 0;
 486                 if (!name) {
 487                         if (whose_ident == WANT_AUTHOR_IDENT && git_author_name.len)
 488                                 name = git_author_name.buf;
 489                         else if (whose_ident == WANT_COMMITTER_IDENT &&
 490                                         git_committer_name.len)
 491                                 name = git_committer_name.buf;
 492                 }
 493                 if (!name) {
 494                         if (strict && ident_use_config_only
 495                             && !(ident_config_given & IDENT_NAME_GIVEN)) {
 496                                 ident_env_hint(whose_ident);
 497                                 die(_("no name was given and auto-detection is disabled"));
 498                         }
 499                         name = ident_default_name();
 500                         using_default = 1;
 501                         if (strict && default_name_is_bogus) {
 502                                 ident_env_hint(whose_ident);
 503                                 die(_("unable to auto-detect name (got '%s')"), name);
 504                         }
 505                 }
 506                 if (!*name) {
 507                         struct passwd *pw;
 508                         if (strict) {
 509                                 if (using_default)
 510                                         ident_env_hint(whose_ident);
 511                                 die(_("empty ident name (for <%s>) not allowed"), email);
 512                         }
 513                         pw = xgetpwuid_self(NULL);
 514                         name = pw->pw_name;
 515                 }
 516                 if (strict && !has_non_crud(name))
 517                         die(_("name consists only of disallowed characters: %s"), name);
 518         }
 519
 520         strbuf_reset(ident);
 521         if (want_name) {
 522                 strbuf_addstr_without_crud(ident, name);
 523                 strbuf_addstr(ident, " <");
 524         }
 525         strbuf_addstr_without_crud(ident, email);
 526         if (want_name)
 527                 strbuf_addch(ident, '>');
 528         if (want_date) {
 529                 strbuf_addch(ident, ' ');
 530                 if (date_str && date_str[0]) {
 531                         if (parse_date(date_str, ident) < 0)
 532                                 die(_("invalid date format: %s"), date_str);
 533                 }
 534                 else
 535                         strbuf_addstr(ident, ident_default_date());
 536         }
 537
 538         return ident->buf;
 539 }
 540
 541 const char *fmt_name(enum want_ident whose_ident)
 542 {
 543         char *name = NULL;
 544         char *email = NULL;
 545
 546         switch (whose_ident) {
 547         case WANT_BLANK_IDENT:
 548                 break;
 549         case WANT_AUTHOR_IDENT:
 550                 name = getenv("GIT_AUTHOR_NAME");
 551                 email = getenv("GIT_AUTHOR_EMAIL");
 552                 break;
 553         case WANT_COMMITTER_IDENT:
 554                 name = getenv("GIT_COMMITTER_NAME");
 555                 email = getenv("GIT_COMMITTER_EMAIL");
 556                 break;
 557         }
 558         return fmt_ident(name, email, whose_ident, NULL,
 559                         IDENT_STRICT | IDENT_NO_DATE);
 560 }
 561
 562 const char *git_author_info(int flag)
 563 {
 564         if (getenv("GIT_AUTHOR_NAME"))
 565                 author_ident_explicitly_given |= IDENT_NAME_GIVEN;
 566         if (getenv("GIT_AUTHOR_EMAIL"))
 567                 author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 568         return fmt_ident(getenv("GIT_AUTHOR_NAME"),
 569                          getenv("GIT_AUTHOR_EMAIL"),
 570                          WANT_AUTHOR_IDENT,
 571                          getenv("GIT_AUTHOR_DATE"),
 572                          flag);
 573 }
 574
 575 const char *git_committer_info(int flag)
 576 {
 577         if (getenv("GIT_COMMITTER_NAME"))
 578                 committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
 579         if (getenv("GIT_COMMITTER_EMAIL"))
 580                 committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 581         return fmt_ident(getenv("GIT_COMMITTER_NAME"),
 582                          getenv("GIT_COMMITTER_EMAIL"),
 583                          WANT_COMMITTER_IDENT,
 584                          getenv("GIT_COMMITTER_DATE"),
 585                          flag);
 586 }
 587
 588 static int ident_is_sufficient(int user_ident_explicitly_given)
 589 {
 590 #ifndef WINDOWS
 591         return (user_ident_explicitly_given & IDENT_MAIL_GIVEN);
 592 #else
 593         return (user_ident_explicitly_given == IDENT_ALL_GIVEN);
 594 #endif
 595 }
 596
 597 int committer_ident_sufficiently_given(void)
 598 {
 599         return ident_is_sufficient(committer_ident_explicitly_given);
 600 }
 601
 602 int author_ident_sufficiently_given(void)
 603 {
 604         return ident_is_sufficient(author_ident_explicitly_given);
 605 }
 606
 607 static int set_ident(const char *var, const char *value)
 608 {
 609         if (!strcmp(var, "author.name")) {
 610                 if (!value)
 611                         return config_error_nonbool(var);
 612                 strbuf_reset(&git_author_name);
 613                 strbuf_addstr(&git_author_name, value);
 614                 author_ident_explicitly_given |= IDENT_NAME_GIVEN;
 615                 ident_config_given |= IDENT_NAME_GIVEN;
 616                 return 0;
 617         }
 618
 619         if (!strcmp(var, "author.email")) {
 620                 if (!value)
 621                         return config_error_nonbool(var);
 622                 strbuf_reset(&git_author_email);
 623                 strbuf_addstr(&git_author_email, value);
 624                 author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 625                 ident_config_given |= IDENT_MAIL_GIVEN;
 626                 return 0;
 627         }
 628
 629         if (!strcmp(var, "committer.name")) {
 630                 if (!value)
 631                         return config_error_nonbool(var);
 632                 strbuf_reset(&git_committer_name);
 633                 strbuf_addstr(&git_committer_name, value);
 634                 committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
 635                 ident_config_given |= IDENT_NAME_GIVEN;
 636                 return 0;
 637         }
 638
 639         if (!strcmp(var, "committer.email")) {
 640                 if (!value)
 641                         return config_error_nonbool(var);
 642                 strbuf_reset(&git_committer_email);
 643                 strbuf_addstr(&git_committer_email, value);
 644                 committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 645                 ident_config_given |= IDENT_MAIL_GIVEN;
 646                 return 0;
 647         }
 648
 649         if (!strcmp(var, "user.name")) {
 650                 if (!value)
 651                         return config_error_nonbool(var);
 652                 strbuf_reset(&git_default_name);
 653                 strbuf_addstr(&git_default_name, value);
 654                 committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
 655                 author_ident_explicitly_given |= IDENT_NAME_GIVEN;
 656                 ident_config_given |= IDENT_NAME_GIVEN;
 657                 return 0;
 658         }
 659
 660         if (!strcmp(var, "user.email")) {
 661                 if (!value)
 662                         return config_error_nonbool(var);
 663                 strbuf_reset(&git_default_email);
 664                 strbuf_addstr(&git_default_email, value);
 665                 committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 666                 author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 667                 ident_config_given |= IDENT_MAIL_GIVEN;
 668                 return 0;
 669         }
 670
 671         return 0;
 672 }
 673
 674 int git_ident_config(const char *var, const char *value,
 675                      const struct config_context *ctx UNUSED,
 676                      void *data UNUSED)
 677 {
 678         if (!strcmp(var, "user.useconfigonly")) {
 679                 ident_use_config_only = git_config_bool(var, value);
 680                 return 0;
 681         }
 682
 683         return set_ident(var, value);
 684 }
 685
 686 static void set_env_if(const char *key, const char *value, int *given, int bit)
 687 {
 688         if ((*given & bit) || getenv(key))
 689                 return; /* nothing to do */
 690         setenv(key, value, 0);
 691         *given |= bit;
 692 }
 693
 694 void prepare_fallback_ident(const char *name, const char *email)
 695 {
 696         set_env_if("GIT_AUTHOR_NAME", name,
 697                    &author_ident_explicitly_given, IDENT_NAME_GIVEN);
 698         set_env_if("GIT_AUTHOR_EMAIL", email,
 699                    &author_ident_explicitly_given, IDENT_MAIL_GIVEN);
 700         set_env_if("GIT_COMMITTER_NAME", name,
 701                    &committer_ident_explicitly_given, IDENT_NAME_GIVEN);
 702         set_env_if("GIT_COMMITTER_EMAIL", email,
 703                    &committer_ident_explicitly_given, IDENT_MAIL_GIVEN);
 704 }
 705
 706 static int buf_cmp(const char *a_begin, const char *a_end,
 707                    const char *b_begin, const char *b_end)
 708 {
 709         int a_len = a_end - a_begin;
 710         int b_len = b_end - b_begin;
 711         int min = a_len < b_len ? a_len : b_len;
 712         int cmp;
 713
 714         cmp = memcmp(a_begin, b_begin, min);
 715         if (cmp)
 716                 return cmp;
 717
 718         return a_len - b_len;
 719 }
 720
 721 int ident_cmp(const struct ident_split *a,
 722               const struct ident_split *b)
 723 {
 724         int cmp;
 725
 726         cmp = buf_cmp(a->mail_begin, a->mail_end,
 727                       b->mail_begin, b->mail_end);
 728         if (cmp)
 729                 return cmp;
 730
 731         return buf_cmp(a->name_begin, a->name_end,
 732                        b->name_begin, b->name_end);
 733 }