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 = (char *) "unknown";
  50 #ifndef NO_GECOS_IN_PWENT
  51                 fallback.pw_gecos = (char *) "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 }
 215
 216 static int has_non_crud(const char *str)
 217 {
 218         for (; *str; str++) {
 219                 if (!crud(*str))
 220                         return 1;
 221         }
 222         return 0;
 223 }
 224
 225 /*
 226  * Copy over a string to the destination, but avoid special
 227  * characters ('\n', '<' and '>') and remove crud at the end
 228  */
 229 static void strbuf_addstr_without_crud(struct strbuf *sb, const char *src)
 230 {
 231         size_t i, len;
 232         unsigned char c;
 233
 234         /* Remove crud from the beginning.. */
 235         while ((c = *src) != 0) {
 236                 if (!crud(c))
 237                         break;
 238                 src++;
 239         }
 240
 241         /* Remove crud from the end.. */
 242         len = strlen(src);
 243         while (len > 0) {
 244                 c = src[len-1];
 245                 if (!crud(c))
 246                         break;
 247                 --len;
 248         }
 249
 250         /*
 251          * Copy the rest to the buffer, but avoid the special
 252          * characters '\n' '<' and '>' that act as delimiters on
 253          * an identification line. We can only remove crud, never add it,
 254          * so 'len' is our maximum.
 255          */
 256         strbuf_grow(sb, len);
 257         for (i = 0; i < len; i++) {
 258                 c = *src++;
 259                 switch (c) {
 260                 case '\n': case '<': case '>':
 261                         continue;
 262                 }
 263                 sb->buf[sb->len++] = c;
 264         }
 265         sb->buf[sb->len] = '\0';
 266 }
 267
 268 /*
 269  * Reverse of fmt_ident(); given an ident line, split the fields
 270  * to allow the caller to parse it.
 271  * Signal a success by returning 0, but date/tz fields of the result
 272  * can still be NULL if the input line only has the name/email part
 273  * (e.g. reading from a reflog entry).
 274  */
 275 int split_ident_line(struct ident_split *split, const char *line, int len)
 276 {
 277         const char *cp;
 278         size_t span;
 279         int status = -1;
 280
 281         memset(split, 0, sizeof(*split));
 282
 283         split->name_begin = line;
 284         for (cp = line; *cp && cp < line + len; cp++)
 285                 if (*cp == '<') {
 286                         split->mail_begin = cp + 1;
 287                         break;
 288                 }
 289         if (!split->mail_begin)
 290                 return status;
 291
 292         for (cp = split->mail_begin - 2; line <= cp; cp--)
 293                 if (!isspace(*cp)) {
 294                         split->name_end = cp + 1;
 295                         break;
 296                 }
 297         if (!split->name_end) {
 298                 /* no human readable name */
 299                 split->name_end = split->name_begin;
 300         }
 301
 302         for (cp = split->mail_begin; cp < line + len; cp++)
 303                 if (*cp == '>') {
 304                         split->mail_end = cp;
 305                         break;
 306                 }
 307         if (!split->mail_end)
 308                 return status;
 309
 310         /*
 311          * Look from the end-of-line to find the trailing ">" of the mail
 312          * address, even though we should already know it as split->mail_end.
 313          * This can help in cases of broken idents with an extra ">" somewhere
 314          * in the email address.  Note that we are assuming the timestamp will
 315          * never have a ">" in it.
 316          *
 317          * Note that we will always find some ">" before going off the front of
 318          * the string, because will always hit the split->mail_end closing
 319          * bracket.
 320          */
 321         for (cp = line + len - 1; *cp != '>'; cp--)
 322                 ;
 323
 324         for (cp = cp + 1; cp < line + len && isspace(*cp); cp++)
 325                 ;
 326         if (line + len <= cp)
 327                 goto person_only;
 328         split->date_begin = cp;
 329         span = strspn(cp, "0123456789");
 330         if (!span)
 331                 goto person_only;
 332         split->date_end = split->date_begin + span;
 333         for (cp = split->date_end; cp < line + len && isspace(*cp); cp++)
 334                 ;
 335         if (line + len <= cp || (*cp != '+' && *cp != '-'))
 336                 goto person_only;
 337         split->tz_begin = cp;
 338         span = strspn(cp + 1, "0123456789");
 339         if (!span)
 340                 goto person_only;
 341         split->tz_end = split->tz_begin + 1 + span;
 342         return 0;
 343
 344 person_only:
 345         split->date_begin = NULL;
 346         split->date_end = NULL;
 347         split->tz_begin = NULL;
 348         split->tz_end = NULL;
 349         return 0;
 350 }
 351
 352 /*
 353  * Returns the difference between the new and old length of the ident line.
 354  */
 355 static ssize_t rewrite_ident_line(const char *person, size_t len,
 356                                    struct strbuf *buf,
 357                                    struct string_list *mailmap)
 358 {
 359         size_t namelen, maillen;
 360         const char *name;
 361         const char *mail;
 362         struct ident_split ident;
 363
 364         if (split_ident_line(&ident, person, len))
 365                 return 0;
 366
 367         mail = ident.mail_begin;
 368         maillen = ident.mail_end - ident.mail_begin;
 369         name = ident.name_begin;
 370         namelen = ident.name_end - ident.name_begin;
 371
 372         if (map_user(mailmap, &mail, &maillen, &name, &namelen)) {
 373                 struct strbuf namemail = STRBUF_INIT;
 374                 size_t newlen;
 375
 376                 strbuf_addf(&namemail, "%.*s <%.*s>",
 377                             (int)namelen, name, (int)maillen, mail);
 378
 379                 strbuf_splice(buf, ident.name_begin - buf->buf,
 380                               ident.mail_end - ident.name_begin + 1,
 381                               namemail.buf, namemail.len);
 382                 newlen = namemail.len;
 383
 384                 strbuf_release(&namemail);
 385
 386                 return newlen - (ident.mail_end - ident.name_begin);
 387         }
 388
 389         return 0;
 390 }
 391
 392 void apply_mailmap_to_header(struct strbuf *buf, const char **header,
 393                                struct string_list *mailmap)
 394 {
 395         size_t buf_offset = 0;
 396
 397         if (!mailmap)
 398                 return;
 399
 400         for (;;) {
 401                 const char *person, *line;
 402                 size_t i;
 403                 int found_header = 0;
 404
 405                 line = buf->buf + buf_offset;
 406                 if (!*line || *line == '\n')
 407                         return; /* End of headers */
 408
 409                 for (i = 0; header[i]; i++)
 410                         if (skip_prefix(line, header[i], &person)) {
 411                                 const char *endp = strchrnul(person, '\n');
 412                                 found_header = 1;
 413                                 buf_offset += endp - line;
 414                                 buf_offset += rewrite_ident_line(person, endp - person, buf, mailmap);
 415                                 break;
 416                         }
 417
 418                 if (!found_header) {
 419                         buf_offset = strchrnul(line, '\n') - buf->buf;
 420                         if (buf->buf[buf_offset] == '\n')
 421                                 buf_offset++;
 422                 }
 423         }
 424 }
 425
 426 static void ident_env_hint(enum want_ident whose_ident)
 427 {
 428         switch (whose_ident) {
 429         case WANT_AUTHOR_IDENT:
 430                 fputs(_("Author identity unknown\n"), stderr);
 431                 break;
 432         case WANT_COMMITTER_IDENT:
 433                 fputs(_("Committer identity unknown\n"), stderr);
 434                 break;
 435         default:
 436                 break;
 437         }
 438
 439         fputs(_("\n"
 440                 "*** Please tell me who you are.\n"
 441                 "\n"
 442                 "Run\n"
 443                 "\n"
 444                 "  git config --global user.email \"you@example.com\"\n"
 445                 "  git config --global user.name \"Your Name\"\n"
 446                 "\n"
 447                 "to set your account\'s default identity.\n"
 448                 "Omit --global to set the identity only in this repository.\n"
 449                 "\n"), stderr);
 450 }
 451
 452 const char *fmt_ident(const char *name, const char *email,
 453                       enum want_ident whose_ident, const char *date_str, int flag)
 454 {
 455         static int index;
 456         static struct strbuf ident_pool[2] = { STRBUF_INIT, STRBUF_INIT };
 457         int strict = (flag & IDENT_STRICT);
 458         int want_date = !(flag & IDENT_NO_DATE);
 459         int want_name = !(flag & IDENT_NO_NAME);
 460
 461         struct strbuf *ident = &ident_pool[index];
 462         index = (index + 1) % ARRAY_SIZE(ident_pool);
 463
 464         if (!email) {
 465                 if (whose_ident == WANT_AUTHOR_IDENT && git_author_email.len)
 466                         email = git_author_email.buf;
 467                 else if (whose_ident == WANT_COMMITTER_IDENT && git_committer_email.len)
 468                         email = git_committer_email.buf;
 469         }
 470         if (!email) {
 471                 if (strict && ident_use_config_only
 472                     && !(ident_config_given & IDENT_MAIL_GIVEN)) {
 473                         ident_env_hint(whose_ident);
 474                         die(_("no email was given and auto-detection is disabled"));
 475                 }
 476                 email = ident_default_email();
 477                 if (strict && default_email_is_bogus) {
 478                         ident_env_hint(whose_ident);
 479                         die(_("unable to auto-detect email address (got '%s')"), email);
 480                 }
 481         }
 482
 483         if (want_name) {
 484                 int using_default = 0;
 485                 if (!name) {
 486                         if (whose_ident == WANT_AUTHOR_IDENT && git_author_name.len)
 487                                 name = git_author_name.buf;
 488                         else if (whose_ident == WANT_COMMITTER_IDENT &&
 489                                         git_committer_name.len)
 490                                 name = git_committer_name.buf;
 491                 }
 492                 if (!name) {
 493                         if (strict && ident_use_config_only
 494                             && !(ident_config_given & IDENT_NAME_GIVEN)) {
 495                                 ident_env_hint(whose_ident);
 496                                 die(_("no name was given and auto-detection is disabled"));
 497                         }
 498                         name = ident_default_name();
 499                         using_default = 1;
 500                         if (strict && default_name_is_bogus) {
 501                                 ident_env_hint(whose_ident);
 502                                 die(_("unable to auto-detect name (got '%s')"), name);
 503                         }
 504                 }
 505                 if (!*name) {
 506                         struct passwd *pw;
 507                         if (strict) {
 508                                 if (using_default)
 509                                         ident_env_hint(whose_ident);
 510                                 die(_("empty ident name (for <%s>) not allowed"), email);
 511                         }
 512                         pw = xgetpwuid_self(NULL);
 513                         name = pw->pw_name;
 514                 }
 515                 if (strict && !has_non_crud(name))
 516                         die(_("name consists only of disallowed characters: %s"), name);
 517         }
 518
 519         strbuf_reset(ident);
 520         if (want_name) {
 521                 strbuf_addstr_without_crud(ident, name);
 522                 strbuf_addstr(ident, " <");
 523         }
 524         strbuf_addstr_without_crud(ident, email);
 525         if (want_name)
 526                 strbuf_addch(ident, '>');
 527         if (want_date) {
 528                 strbuf_addch(ident, ' ');
 529                 if (date_str && date_str[0]) {
 530                         if (parse_date(date_str, ident) < 0)
 531                                 die(_("invalid date format: %s"), date_str);
 532                 }
 533                 else
 534                         strbuf_addstr(ident, ident_default_date());
 535         }
 536
 537         return ident->buf;
 538 }
 539
 540 const char *fmt_name(enum want_ident whose_ident)
 541 {
 542         char *name = NULL;
 543         char *email = NULL;
 544
 545         switch (whose_ident) {
 546         case WANT_BLANK_IDENT:
 547                 break;
 548         case WANT_AUTHOR_IDENT:
 549                 name = getenv("GIT_AUTHOR_NAME");
 550                 email = getenv("GIT_AUTHOR_EMAIL");
 551                 break;
 552         case WANT_COMMITTER_IDENT:
 553                 name = getenv("GIT_COMMITTER_NAME");
 554                 email = getenv("GIT_COMMITTER_EMAIL");
 555                 break;
 556         }
 557         return fmt_ident(name, email, whose_ident, NULL,
 558                         IDENT_STRICT | IDENT_NO_DATE);
 559 }
 560
 561 const char *git_author_info(int flag)
 562 {
 563         if (getenv("GIT_AUTHOR_NAME"))
 564                 author_ident_explicitly_given |= IDENT_NAME_GIVEN;
 565         if (getenv("GIT_AUTHOR_EMAIL"))
 566                 author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 567         return fmt_ident(getenv("GIT_AUTHOR_NAME"),
 568                          getenv("GIT_AUTHOR_EMAIL"),
 569                          WANT_AUTHOR_IDENT,
 570                          getenv("GIT_AUTHOR_DATE"),
 571                          flag);
 572 }
 573
 574 const char *git_committer_info(int flag)
 575 {
 576         if (getenv("GIT_COMMITTER_NAME"))
 577                 committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
 578         if (getenv("GIT_COMMITTER_EMAIL"))
 579                 committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 580         return fmt_ident(getenv("GIT_COMMITTER_NAME"),
 581                          getenv("GIT_COMMITTER_EMAIL"),
 582                          WANT_COMMITTER_IDENT,
 583                          getenv("GIT_COMMITTER_DATE"),
 584                          flag);
 585 }
 586
 587 static int ident_is_sufficient(int user_ident_explicitly_given)
 588 {
 589 #ifndef WINDOWS
 590         return (user_ident_explicitly_given & IDENT_MAIL_GIVEN);
 591 #else
 592         return (user_ident_explicitly_given == IDENT_ALL_GIVEN);
 593 #endif
 594 }
 595
 596 int committer_ident_sufficiently_given(void)
 597 {
 598         return ident_is_sufficient(committer_ident_explicitly_given);
 599 }
 600
 601 int author_ident_sufficiently_given(void)
 602 {
 603         return ident_is_sufficient(author_ident_explicitly_given);
 604 }
 605
 606 static int set_ident(const char *var, const char *value)
 607 {
 608         if (!strcmp(var, "author.name")) {
 609                 if (!value)
 610                         return config_error_nonbool(var);
 611                 strbuf_reset(&git_author_name);
 612                 strbuf_addstr(&git_author_name, value);
 613                 author_ident_explicitly_given |= IDENT_NAME_GIVEN;
 614                 ident_config_given |= IDENT_NAME_GIVEN;
 615                 return 0;
 616         }
 617
 618         if (!strcmp(var, "author.email")) {
 619                 if (!value)
 620                         return config_error_nonbool(var);
 621                 strbuf_reset(&git_author_email);
 622                 strbuf_addstr(&git_author_email, value);
 623                 author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 624                 ident_config_given |= IDENT_MAIL_GIVEN;
 625                 return 0;
 626         }
 627
 628         if (!strcmp(var, "committer.name")) {
 629                 if (!value)
 630                         return config_error_nonbool(var);
 631                 strbuf_reset(&git_committer_name);
 632                 strbuf_addstr(&git_committer_name, value);
 633                 committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
 634                 ident_config_given |= IDENT_NAME_GIVEN;
 635                 return 0;
 636         }
 637
 638         if (!strcmp(var, "committer.email")) {
 639                 if (!value)
 640                         return config_error_nonbool(var);
 641                 strbuf_reset(&git_committer_email);
 642                 strbuf_addstr(&git_committer_email, value);
 643                 committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 644                 ident_config_given |= IDENT_MAIL_GIVEN;
 645                 return 0;
 646         }
 647
 648         if (!strcmp(var, "user.name")) {
 649                 if (!value)
 650                         return config_error_nonbool(var);
 651                 strbuf_reset(&git_default_name);
 652                 strbuf_addstr(&git_default_name, value);
 653                 committer_ident_explicitly_given |= IDENT_NAME_GIVEN;
 654                 author_ident_explicitly_given |= IDENT_NAME_GIVEN;
 655                 ident_config_given |= IDENT_NAME_GIVEN;
 656                 return 0;
 657         }
 658
 659         if (!strcmp(var, "user.email")) {
 660                 if (!value)
 661                         return config_error_nonbool(var);
 662                 strbuf_reset(&git_default_email);
 663                 strbuf_addstr(&git_default_email, value);
 664                 committer_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 665                 author_ident_explicitly_given |= IDENT_MAIL_GIVEN;
 666                 ident_config_given |= IDENT_MAIL_GIVEN;
 667                 return 0;
 668         }
 669
 670         return 0;
 671 }
 672
 673 int git_ident_config(const char *var, const char *value,
 674                      const struct config_context *ctx UNUSED,
 675                      void *data UNUSED)
 676 {
 677         if (!strcmp(var, "user.useconfigonly")) {
 678                 ident_use_config_only = git_config_bool(var, value);
 679                 return 0;
 680         }
 681
 682         return set_ident(var, value);
 683 }
 684
 685 static void set_env_if(const char *key, const char *value, int *given, int bit)
 686 {
 687         if ((*given & bit) || getenv(key))
 688                 return; /* nothing to do */
 689         setenv(key, value, 0);
 690         *given |= bit;
 691 }
 692
 693 void prepare_fallback_ident(const char *name, const char *email)
 694 {
 695         set_env_if("GIT_AUTHOR_NAME", name,
 696                    &author_ident_explicitly_given, IDENT_NAME_GIVEN);
 697         set_env_if("GIT_AUTHOR_EMAIL", email,
 698                    &author_ident_explicitly_given, IDENT_MAIL_GIVEN);
 699         set_env_if("GIT_COMMITTER_NAME", name,
 700                    &committer_ident_explicitly_given, IDENT_NAME_GIVEN);
 701         set_env_if("GIT_COMMITTER_EMAIL", email,
 702                    &committer_ident_explicitly_given, IDENT_MAIL_GIVEN);
 703 }
 704
 705 static int buf_cmp(const char *a_begin, const char *a_end,
 706                    const char *b_begin, const char *b_end)
 707 {
 708         int a_len = a_end - a_begin;
 709         int b_len = b_end - b_begin;
 710         int min = a_len < b_len ? a_len : b_len;
 711         int cmp;
 712
 713         cmp = memcmp(a_begin, b_begin, min);
 714         if (cmp)
 715                 return cmp;
 716
 717         return a_len - b_len;
 718 }
 719
 720 int ident_cmp(const struct ident_split *a,
 721               const struct ident_split *b)
 722 {
 723         int cmp;
 724
 725         cmp = buf_cmp(a->mail_begin, a->mail_end,
 726                       b->mail_begin, b->mail_end);
 727         if (cmp)
 728                 return cmp;
 729
 730         return buf_cmp(a->name_begin, a->name_end,
 731                        b->name_begin, b->name_end);
 732 }