builtin-mailinfo.c

   1 /*
   2  * Another stupid program, this one parsing the headers of an
   3  * email to figure out authorship and subject
   4  */
   5 #include "cache.h"
   6 #include "builtin.h"
   7
   8 static FILE *cmitmsg, *patchfile, *fin, *fout;
   9
  10 static int keep_subject;
  11 static const char *metainfo_charset;
  12 static char line[1000];
  13 static char date[1000];
  14 static char name[1000];
  15 static char email[1000];
  16 static char subject[1000];
  17
  18 static enum  {
  19         TE_DONTCARE, TE_QP, TE_BASE64,
  20 } transfer_encoding;
  21 static char charset[256];
  22
  23 static char multipart_boundary[1000];
  24 static int multipart_boundary_len;
  25 static int patch_lines;
  26
  27 static char *sanity_check(char *name, char *email)
  28 {
  29         int len = strlen(name);
  30         if (len < 3 || len > 60)
  31                 return email;
  32         if (strchr(name, '@') || strchr(name, '<') || strchr(name, '>'))
  33                 return email;
  34         return name;
  35 }
  36
  37 static int bogus_from(char *line)
  38 {
  39         /* John Doe <johndoe> */
  40         char *bra, *ket, *dst, *cp;
  41
  42         /* This is fallback, so do not bother if we already have an
  43          * e-mail address.
  44          */
  45         if (*email)
  46                 return 0;
  47
  48         bra = strchr(line, '<');
  49         if (!bra)
  50                 return 0;
  51         ket = strchr(bra, '>');
  52         if (!ket)
  53                 return 0;
  54
  55         for (dst = email, cp = bra+1; cp < ket; )
  56                 *dst++ = *cp++;
  57         *dst = 0;
  58         for (cp = line; isspace(*cp); cp++)
  59                 ;
  60         for (bra--; isspace(*bra); bra--)
  61                 *bra = 0;
  62         cp = sanity_check(cp, email);
  63         strcpy(name, cp);
  64         return 1;
  65 }
  66
  67 static int handle_from(char *in_line)
  68 {
  69         char line[1000];
  70         char *at;
  71         char *dst;
  72
  73         strcpy(line, in_line);
  74         at = strchr(line, '@');
  75         if (!at)
  76                 return bogus_from(line);
  77
  78         /*
  79          * If we already have one email, don't take any confusing lines
  80          */
  81         if (*email && strchr(at+1, '@'))
  82                 return 0;
  83
  84         /* Pick up the string around '@', possibly delimited with <>
  85          * pair; that is the email part.  White them out while copying.
  86          */
  87         while (at > line) {
  88                 char c = at[-1];
  89                 if (isspace(c))
  90                         break;
  91                 if (c == '<') {
  92                         at[-1] = ' ';
  93                         break;
  94                 }
  95                 at--;
  96         }
  97         dst = email;
  98         for (;;) {
  99                 unsigned char c = *at;
 100                 if (!c || c == '>' || isspace(c)) {
 101                         if (c == '>')
 102                                 *at = ' ';
 103                         break;
 104                 }
 105                 *at++ = ' ';
 106                 *dst++ = c;
 107         }
 108         *dst++ = 0;
 109
 110         /* The remainder is name.  It could be "John Doe <john.doe@xz>"
 111          * or "john.doe@xz (John Doe)", but we have whited out the
 112          * email part, so trim from both ends, possibly removing
 113          * the () pair at the end.
 114          */
 115         at = line + strlen(line);
 116         while (at > line) {
 117                 unsigned char c = *--at;
 118                 if (!isspace(c)) {
 119                         at[(c == ')') ? 0 : 1] = 0;
 120                         break;
 121                 }
 122         }
 123
 124         at = line;
 125         for (;;) {
 126                 unsigned char c = *at;
 127                 if (!c || !isspace(c)) {
 128                         if (c == '(')
 129                                 at++;
 130                         break;
 131                 }
 132                 at++;
 133         }
 134         at = sanity_check(at, email);
 135         strcpy(name, at);
 136         return 1;
 137 }
 138
 139 static int handle_date(char *line)
 140 {
 141         strcpy(date, line);
 142         return 0;
 143 }
 144
 145 static int handle_subject(char *line)
 146 {
 147         strcpy(subject, line);
 148         return 0;
 149 }
 150
 151 /* NOTE NOTE NOTE.  We do not claim we do full MIME.  We just attempt
 152  * to have enough heuristics to grok MIME encoded patches often found
 153  * on our mailing lists.  For example, we do not even treat header lines
 154  * case insensitively.
 155  */
 156
 157 static int slurp_attr(const char *line, const char *name, char *attr)
 158 {
 159         const char *ends, *ap = strcasestr(line, name);
 160         size_t sz;
 161
 162         if (!ap) {
 163                 *attr = 0;
 164                 return 0;
 165         }
 166         ap += strlen(name);
 167         if (*ap == '"') {
 168                 ap++;
 169                 ends = "\"";
 170         }
 171         else
 172                 ends = "; \t";
 173         sz = strcspn(ap, ends);
 174         memcpy(attr, ap, sz);
 175         attr[sz] = 0;
 176         return 1;
 177 }
 178
 179 static int handle_subcontent_type(char *line)
 180 {
 181         /* We do not want to mess with boundary.  Note that we do not
 182          * handle nested multipart.
 183          */
 184         if (strcasestr(line, "boundary=")) {
 185                 fprintf(stderr, "Not handling nested multipart message.\n");
 186                 exit(1);
 187         }
 188         slurp_attr(line, "charset=", charset);
 189         if (*charset) {
 190                 int i, c;
 191                 for (i = 0; (c = charset[i]) != 0; i++)
 192                         charset[i] = tolower(c);
 193         }
 194         return 0;
 195 }
 196
 197 static int handle_content_type(char *line)
 198 {
 199         *multipart_boundary = 0;
 200         if (slurp_attr(line, "boundary=", multipart_boundary + 2)) {
 201                 memcpy(multipart_boundary, "--", 2);
 202                 multipart_boundary_len = strlen(multipart_boundary);
 203         }
 204         slurp_attr(line, "charset=", charset);
 205         return 0;
 206 }
 207
 208 static int handle_content_transfer_encoding(char *line)
 209 {
 210         if (strcasestr(line, "base64"))
 211                 transfer_encoding = TE_BASE64;
 212         else if (strcasestr(line, "quoted-printable"))
 213                 transfer_encoding = TE_QP;
 214         else
 215                 transfer_encoding = TE_DONTCARE;
 216         return 0;
 217 }
 218
 219 static int is_multipart_boundary(const char *line)
 220 {
 221         return (!memcmp(line, multipart_boundary, multipart_boundary_len));
 222 }
 223
 224 static int eatspace(char *line)
 225 {
 226         int len = strlen(line);
 227         while (len > 0 && isspace(line[len-1]))
 228                 line[--len] = 0;
 229         return len;
 230 }
 231
 232 #define SEEN_FROM 01
 233 #define SEEN_DATE 02
 234 #define SEEN_SUBJECT 04
 235 #define SEEN_BOGUS_UNIX_FROM 010
 236 #define SEEN_PREFIX  020
 237
 238 /* First lines of body can have From:, Date:, and Subject: or empty */
 239 static void handle_inbody_header(int *seen, char *line)
 240 {
 241         if (*seen & SEEN_PREFIX)
 242                 return;
 243         if (isspace(*line)) {
 244                 char *cp;
 245                 for (cp = line + 1; *cp; cp++) {
 246                         if (!isspace(*cp))
 247                                 break;
 248                 }
 249                 if (!*cp)
 250                         return;
 251         }
 252         if (!memcmp(">From", line, 5) && isspace(line[5])) {
 253                 if (!(*seen & SEEN_BOGUS_UNIX_FROM)) {
 254                         *seen |= SEEN_BOGUS_UNIX_FROM;
 255                         return;
 256                 }
 257         }
 258         if (!memcmp("From:", line, 5) && isspace(line[5])) {
 259                 if (!(*seen & SEEN_FROM) && handle_from(line+6)) {
 260                         *seen |= SEEN_FROM;
 261                         return;
 262                 }
 263         }
 264         if (!memcmp("Date:", line, 5) && isspace(line[5])) {
 265                 if (!(*seen & SEEN_DATE)) {
 266                         handle_date(line+6);
 267                         *seen |= SEEN_DATE;
 268                         return;
 269                 }
 270         }
 271         if (!memcmp("Subject:", line, 8) && isspace(line[8])) {
 272                 if (!(*seen & SEEN_SUBJECT)) {
 273                         handle_subject(line+9);
 274                         *seen |= SEEN_SUBJECT;
 275                         return;
 276                 }
 277         }
 278         if (!memcmp("[PATCH]", line, 7) && isspace(line[7])) {
 279                 if (!(*seen & SEEN_SUBJECT)) {
 280                         handle_subject(line);
 281                         *seen |= SEEN_SUBJECT;
 282                         return;
 283                 }
 284         }
 285         *seen |= SEEN_PREFIX;
 286 }
 287
 288 static char *cleanup_subject(char *subject)
 289 {
 290         if (keep_subject)
 291                 return subject;
 292         for (;;) {
 293                 char *p;
 294                 int len, remove;
 295                 switch (*subject) {
 296                 case 'r': case 'R':
 297                         if (!memcmp("e:", subject+1, 2)) {
 298                                 subject +=3;
 299                                 continue;
 300                         }
 301                         break;
 302                 case ' ': case '\t': case ':':
 303                         subject++;
 304                         continue;
 305
 306                 case '[':
 307                         p = strchr(subject, ']');
 308                         if (!p) {
 309                                 subject++;
 310                                 continue;
 311                         }
 312                         len = strlen(p);
 313                         remove = p - subject;
 314                         if (remove <= len *2) {
 315                                 subject = p+1;
 316                                 continue;
 317                         }
 318                         break;
 319                 }
 320                 eatspace(subject);
 321                 return subject;
 322         }
 323 }
 324
 325 static void cleanup_space(char *buf)
 326 {
 327         unsigned char c;
 328         while ((c = *buf) != 0) {
 329                 buf++;
 330                 if (isspace(c)) {
 331                         buf[-1] = ' ';
 332                         c = *buf;
 333                         while (isspace(c)) {
 334                                 int len = strlen(buf);
 335                                 memmove(buf, buf+1, len);
 336                                 c = *buf;
 337                         }
 338                 }
 339         }
 340 }
 341
 342 static void decode_header(char *it);
 343 typedef int (*header_fn_t)(char *);
 344 struct header_def {
 345         const char *name;
 346         header_fn_t func;
 347         int namelen;
 348 };
 349
 350 static void check_header(char *line, struct header_def *header)
 351 {
 352         int i;
 353
 354         if (header[0].namelen <= 0) {
 355                 for (i = 0; header[i].name; i++)
 356                         header[i].namelen = strlen(header[i].name);
 357         }
 358         for (i = 0; header[i].name; i++) {
 359                 int len = header[i].namelen;
 360                 if (!strncasecmp(line, header[i].name, len) &&
 361                     line[len] == ':' && isspace(line[len + 1])) {
 362                         /* Unwrap inline B and Q encoding, and optionally
 363                          * normalize the meta information to utf8.
 364                          */
 365                         decode_header(line + len + 2);
 366                         header[i].func(line + len + 2);
 367                         break;
 368                 }
 369         }
 370 }
 371
 372 static void check_subheader_line(char *line)
 373 {
 374         static struct header_def header[] = {
 375                 { "Content-Type", handle_subcontent_type },
 376                 { "Content-Transfer-Encoding",
 377                   handle_content_transfer_encoding },
 378                 { NULL },
 379         };
 380         check_header(line, header);
 381 }
 382 static void check_header_line(char *line)
 383 {
 384         static struct header_def header[] = {
 385                 { "From", handle_from },
 386                 { "Date", handle_date },
 387                 { "Subject", handle_subject },
 388                 { "Content-Type", handle_content_type },
 389                 { "Content-Transfer-Encoding",
 390                   handle_content_transfer_encoding },
 391                 { NULL },
 392         };
 393         check_header(line, header);
 394 }
 395
 396 static int is_rfc2822_header(char *line)
 397 {
 398         /*
 399          * The section that defines the loosest possible
 400          * field name is "3.6.8 Optional fields".
 401          *
 402          * optional-field = field-name ":" unstructured CRLF
 403          * field-name = 1*ftext
 404          * ftext = %d33-57 / %59-126
 405          */
 406         int ch;
 407         char *cp = line;
 408         while ((ch = *cp++)) {
 409                 if (ch == ':')
 410                         return cp != line;
 411                 if ((33 <= ch && ch <= 57) ||
 412                     (59 <= ch && ch <= 126))
 413                         continue;
 414                 break;
 415         }
 416         return 0;
 417 }
 418
 419 static int read_one_header_line(char *line, int sz, FILE *in)
 420 {
 421         int ofs = 0;
 422         while (ofs < sz) {
 423                 int peek, len;
 424                 if (fgets(line + ofs, sz - ofs, in) == NULL)
 425                         break;
 426                 len = eatspace(line + ofs);
 427                 if ((len == 0) || !is_rfc2822_header(line)) {
 428                         /* Re-add the newline */
 429                         line[ofs + len] = '\n';
 430                         line[ofs + len + 1] = '\0';
 431                         break;
 432                 }
 433                 ofs += len;
 434                 /* Yuck, 2822 header "folding" */
 435                 peek = fgetc(in); ungetc(peek, in);
 436                 if (peek != ' ' && peek != '\t')
 437                         break;
 438         }
 439         /* Count mbox From headers as headers */
 440         if (!ofs && (!memcmp(line, "From ", 5) || !memcmp(line, ">From ", 6)))
 441                 ofs = 1;
 442         return ofs;
 443 }
 444
 445 static int decode_q_segment(char *in, char *ot, char *ep, int rfc2047)
 446 {
 447         int c;
 448         while ((c = *in++) != 0 && (in <= ep)) {
 449                 if (c == '=') {
 450                         int d = *in++;
 451                         if (d == '\n' || !d)
 452                                 break; /* drop trailing newline */
 453                         *ot++ = ((hexval(d) << 4) | hexval(*in++));
 454                         continue;
 455                 }
 456                 if (rfc2047 && c == '_') /* rfc2047 4.2 (2) */
 457                         c = 0x20;
 458                 *ot++ = c;
 459         }
 460         *ot = 0;
 461         return 0;
 462 }
 463
 464 static int decode_b_segment(char *in, char *ot, char *ep)
 465 {
 466         /* Decode in..ep, possibly in-place to ot */
 467         int c, pos = 0, acc = 0;
 468
 469         while ((c = *in++) != 0 && (in <= ep)) {
 470                 if (c == '+')
 471                         c = 62;
 472                 else if (c == '/')
 473                         c = 63;
 474                 else if ('A' <= c && c <= 'Z')
 475                         c -= 'A';
 476                 else if ('a' <= c && c <= 'z')
 477                         c -= 'a' - 26;
 478                 else if ('0' <= c && c <= '9')
 479                         c -= '0' - 52;
 480                 else if (c == '=') {
 481                         /* padding is almost like (c == 0), except we do
 482                          * not output NUL resulting only from it;
 483                          * for now we just trust the data.
 484                          */
 485                         c = 0;
 486                 }
 487                 else
 488                         continue; /* garbage */
 489                 switch (pos++) {
 490                 case 0:
 491                         acc = (c << 2);
 492                         break;
 493                 case 1:
 494                         *ot++ = (acc | (c >> 4));
 495                         acc = (c & 15) << 4;
 496                         break;
 497                 case 2:
 498                         *ot++ = (acc | (c >> 2));
 499                         acc = (c & 3) << 6;
 500                         break;
 501                 case 3:
 502                         *ot++ = (acc | c);
 503                         acc = pos = 0;
 504                         break;
 505                 }
 506         }
 507         *ot = 0;
 508         return 0;
 509 }
 510
 511 static void convert_to_utf8(char *line, char *charset)
 512 {
 513 #ifndef NO_ICONV
 514         char *in, *out;
 515         size_t insize, outsize, nrc;
 516         char outbuf[4096]; /* cheat */
 517         static char latin_one[] = "latin1";
 518         char *input_charset = *charset ? charset : latin_one;
 519         iconv_t conv = iconv_open(metainfo_charset, input_charset);
 520
 521         if (conv == (iconv_t) -1) {
 522                 static int warned_latin1_once = 0;
 523                 if (input_charset != latin_one) {
 524                         fprintf(stderr, "cannot convert from %s to %s\n",
 525                                 input_charset, metainfo_charset);
 526                         *charset = 0;
 527                 }
 528                 else if (!warned_latin1_once) {
 529                         warned_latin1_once = 1;
 530                         fprintf(stderr, "tried to convert from %s to %s, "
 531                                 "but your iconv does not work with it.\n",
 532                                 input_charset, metainfo_charset);
 533                 }
 534                 return;
 535         }
 536         in = line;
 537         insize = strlen(in);
 538         out = outbuf;
 539         outsize = sizeof(outbuf);
 540         nrc = iconv(conv, &in, &insize, &out, &outsize);
 541         iconv_close(conv);
 542         if (nrc == (size_t) -1)
 543                 return;
 544         *out = 0;
 545         strcpy(line, outbuf);
 546 #endif
 547 }
 548
 549 static int decode_header_bq(char *it)
 550 {
 551         char *in, *out, *ep, *cp, *sp;
 552         char outbuf[1000];
 553         int rfc2047 = 0;
 554
 555         in = it;
 556         out = outbuf;
 557         while ((ep = strstr(in, "=?")) != NULL) {
 558                 int sz, encoding;
 559                 char charset_q[256], piecebuf[256];
 560                 rfc2047 = 1;
 561
 562                 if (in != ep) {
 563                         sz = ep - in;
 564                         memcpy(out, in, sz);
 565                         out += sz;
 566                         in += sz;
 567                 }
 568                 /* E.g.
 569                  * ep : "=?iso-2022-jp?B?GyR...?= foo"
 570                  * ep : "=?ISO-8859-1?Q?Foo=FCbar?= baz"
 571                  */
 572                 ep += 2;
 573                 cp = strchr(ep, '?');
 574                 if (!cp)
 575                         return rfc2047; /* no munging */
 576                 for (sp = ep; sp < cp; sp++)
 577                         charset_q[sp - ep] = tolower(*sp);
 578                 charset_q[cp - ep] = 0;
 579                 encoding = cp[1];
 580                 if (!encoding || cp[2] != '?')
 581                         return rfc2047; /* no munging */
 582                 ep = strstr(cp + 3, "?=");
 583                 if (!ep)
 584                         return rfc2047; /* no munging */
 585                 switch (tolower(encoding)) {
 586                 default:
 587                         return rfc2047; /* no munging */
 588                 case 'b':
 589                         sz = decode_b_segment(cp + 3, piecebuf, ep);
 590                         break;
 591                 case 'q':
 592                         sz = decode_q_segment(cp + 3, piecebuf, ep, 1);
 593                         break;
 594                 }
 595                 if (sz < 0)
 596                         return rfc2047;
 597                 if (metainfo_charset)
 598                         convert_to_utf8(piecebuf, charset_q);
 599                 strcpy(out, piecebuf);
 600                 out += strlen(out);
 601                 in = ep + 2;
 602         }
 603         strcpy(out, in);
 604         strcpy(it, outbuf);
 605         return rfc2047;
 606 }
 607
 608 static void decode_header(char *it)
 609 {
 610
 611         if (decode_header_bq(it))
 612                 return;
 613         /* otherwise "it" is a straight copy of the input.
 614          * This can be binary guck but there is no charset specified.
 615          */
 616         if (metainfo_charset)
 617                 convert_to_utf8(it, "");
 618 }
 619
 620 static void decode_transfer_encoding(char *line)
 621 {
 622         char *ep;
 623
 624         switch (transfer_encoding) {
 625         case TE_QP:
 626                 ep = line + strlen(line);
 627                 decode_q_segment(line, line, ep, 0);
 628                 break;
 629         case TE_BASE64:
 630                 ep = line + strlen(line);
 631                 decode_b_segment(line, line, ep);
 632                 break;
 633         case TE_DONTCARE:
 634                 break;
 635         }
 636 }
 637
 638 static void handle_info(void)
 639 {
 640         char *sub;
 641
 642         sub = cleanup_subject(subject);
 643         cleanup_space(name);
 644         cleanup_space(date);
 645         cleanup_space(email);
 646         cleanup_space(sub);
 647
 648         fprintf(fout, "Author: %s\nEmail: %s\nSubject: %s\nDate: %s\n\n",
 649                name, email, sub, date);
 650 }
 651
 652 /* We are inside message body and have read line[] already.
 653  * Spit out the commit log.
 654  */
 655 static int handle_commit_msg(int *seen)
 656 {
 657         if (!cmitmsg)
 658                 return 0;
 659         do {
 660                 if (!memcmp("diff -", line, 6) ||
 661                     !memcmp("---", line, 3) ||
 662                     !memcmp("Index: ", line, 7))
 663                         break;
 664                 if ((multipart_boundary[0] && is_multipart_boundary(line))) {
 665                         /* We come here when the first part had only
 666                          * the commit message without any patch.  We
 667                          * pretend we have not seen this line yet, and
 668                          * go back to the loop.
 669                          */
 670                         return 1;
 671                 }
 672
 673                 /* Unwrap transfer encoding and optionally
 674                  * normalize the log message to UTF-8.
 675                  */
 676                 decode_transfer_encoding(line);
 677                 if (metainfo_charset)
 678                         convert_to_utf8(line, charset);
 679
 680                 handle_inbody_header(seen, line);
 681                 if (!(*seen & SEEN_PREFIX))
 682                         continue;
 683
 684                 fputs(line, cmitmsg);
 685         } while (fgets(line, sizeof(line), fin) != NULL);
 686         fclose(cmitmsg);
 687         cmitmsg = NULL;
 688         return 0;
 689 }
 690
 691 /* We have done the commit message and have the first
 692  * line of the patch in line[].
 693  */
 694 static void handle_patch(void)
 695 {
 696         do {
 697                 if (multipart_boundary[0] && is_multipart_boundary(line))
 698                         break;
 699                 /* Only unwrap transfer encoding but otherwise do not
 700                  * do anything.  We do *NOT* want UTF-8 conversion
 701                  * here; we are dealing with the user payload.
 702                  */
 703                 decode_transfer_encoding(line);
 704                 fputs(line, patchfile);
 705                 patch_lines++;
 706         } while (fgets(line, sizeof(line), fin) != NULL);
 707 }
 708
 709 /* multipart boundary and transfer encoding are set up for us, and we
 710  * are at the end of the sub header.  do equivalent of handle_body up
 711  * to the next boundary without closing patchfile --- we will expect
 712  * that the first part to contain commit message and a patch, and
 713  * handle other parts as pure patches.
 714  */
 715 static int handle_multipart_one_part(int *seen)
 716 {
 717         int n = 0;
 718
 719         while (fgets(line, sizeof(line), fin) != NULL) {
 720         again:
 721                 n++;
 722                 if (is_multipart_boundary(line))
 723                         break;
 724                 if (handle_commit_msg(seen))
 725                         goto again;
 726                 handle_patch();
 727                 break;
 728         }
 729         if (n == 0)
 730                 return -1;
 731         return 0;
 732 }
 733
 734 static void handle_multipart_body(void)
 735 {
 736         int seen = 0;
 737         int part_num = 0;
 738
 739         /* Skip up to the first boundary */
 740         while (fgets(line, sizeof(line), fin) != NULL)
 741                 if (is_multipart_boundary(line)) {
 742                         part_num = 1;
 743                         break;
 744                 }
 745         if (!part_num)
 746                 return;
 747         /* We are on boundary line.  Start slurping the subhead. */
 748         while (1) {
 749                 int hdr = read_one_header_line(line, sizeof(line), fin);
 750                 if (!hdr) {
 751                         if (handle_multipart_one_part(&seen) < 0)
 752                                 return;
 753                         /* Reset per part headers */
 754                         transfer_encoding = TE_DONTCARE;
 755                         charset[0] = 0;
 756                 }
 757                 else
 758                         check_subheader_line(line);
 759         }
 760         fclose(patchfile);
 761         if (!patch_lines) {
 762                 fprintf(stderr, "No patch found\n");
 763                 exit(1);
 764         }
 765 }
 766
 767 /* Non multipart message */
 768 static void handle_body(void)
 769 {
 770         int seen = 0;
 771
 772         handle_commit_msg(&seen);
 773         handle_patch();
 774         fclose(patchfile);
 775         if (!patch_lines) {
 776                 fprintf(stderr, "No patch found\n");
 777                 exit(1);
 778         }
 779 }
 780
 781 int mailinfo(FILE *in, FILE *out, int ks, const char *encoding,
 782              const char *msg, const char *patch)
 783 {
 784         keep_subject = ks;
 785         metainfo_charset = encoding;
 786         fin = in;
 787         fout = out;
 788
 789         cmitmsg = fopen(msg, "w");
 790         if (!cmitmsg) {
 791                 perror(msg);
 792                 return -1;
 793         }
 794         patchfile = fopen(patch, "w");
 795         if (!patchfile) {
 796                 perror(patch);
 797                 fclose(cmitmsg);
 798                 return -1;
 799         }
 800         while (1) {
 801                 int hdr = read_one_header_line(line, sizeof(line), fin);
 802                 if (!hdr) {
 803                         if (multipart_boundary[0])
 804                                 handle_multipart_body();
 805                         else
 806                                 handle_body();
 807                         handle_info();
 808                         break;
 809                 }
 810                 check_header_line(line);
 811         }
 812
 813         return 0;
 814 }
 815
 816 static const char mailinfo_usage[] =
 817         "git-mailinfo [-k] [-u | --encoding=<encoding>] msg patch <mail >info";
 818
 819 int cmd_mailinfo(int argc, const char **argv, const char *prefix)
 820 {
 821         /* NEEDSWORK: might want to do the optional .git/ directory
 822          * discovery
 823          */
 824         git_config(git_default_config);
 825
 826         while (1 < argc && argv[1][0] == '-') {
 827                 if (!strcmp(argv[1], "-k"))
 828                         keep_subject = 1;
 829                 else if (!strcmp(argv[1], "-u"))
 830                         metainfo_charset = git_commit_encoding;
 831                 else if (!strncmp(argv[1], "--encoding=", 11))
 832                         metainfo_charset = argv[1] + 11;
 833                 else
 834                         usage(mailinfo_usage);
 835                 argc--; argv++;
 836         }
 837
 838         if (argc != 3)
 839                 usage(mailinfo_usage);
 840
 841         return !!mailinfo(stdin, stdout, keep_subject, metainfo_charset, argv[1], argv[2]);
 842 }