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 #include "utf8.h"
   8 #include "strbuf.h"
   9
  10 static FILE *cmitmsg, *patchfile, *fin, *fout;
  11
  12 static int keep_subject;
  13 static const char *metainfo_charset;
  14 static struct strbuf line = STRBUF_INIT;
  15 static struct strbuf name = STRBUF_INIT;
  16 static struct strbuf email = STRBUF_INIT;
  17
  18 static enum  {
  19         TE_DONTCARE, TE_QP, TE_BASE64,
  20 } transfer_encoding;
  21 static enum  {
  22         TYPE_TEXT, TYPE_OTHER,
  23 } message_type;
  24
  25 static struct strbuf charset = STRBUF_INIT;
  26 static int patch_lines;
  27 static struct strbuf **p_hdr_data, **s_hdr_data;
  28
  29 #define MAX_HDR_PARSED 10
  30 #define MAX_BOUNDARIES 5
  31
  32 static void get_sane_name(struct strbuf *out, struct strbuf *name, struct strbuf *email)
  33 {
  34         struct strbuf *src = name;
  35         if (name->len < 3 || 60 < name->len || strchr(name->buf, '@') ||
  36                 strchr(name->buf, '<') || strchr(name->buf, '>'))
  37                 src = email;
  38         else if (name == out)
  39                 return;
  40         strbuf_reset(out);
  41         strbuf_addbuf(out, src);
  42 }
  43
  44 static void parse_bogus_from(const struct strbuf *line)
  45 {
  46         /* John Doe <johndoe> */
  47
  48         char *bra, *ket;
  49         /* This is fallback, so do not bother if we already have an
  50          * e-mail address.
  51          */
  52         if (email.len)
  53                 return;
  54
  55         bra = strchr(line->buf, '<');
  56         if (!bra)
  57                 return;
  58         ket = strchr(bra, '>');
  59         if (!ket)
  60                 return;
  61
  62         strbuf_reset(&email);
  63         strbuf_add(&email, bra + 1, ket - bra - 1);
  64
  65         strbuf_reset(&name);
  66         strbuf_add(&name, line->buf, bra - line->buf);
  67         strbuf_trim(&name);
  68         get_sane_name(&name, &name, &email);
  69 }
  70
  71 static void handle_from(const struct strbuf *from)
  72 {
  73         char *at;
  74         size_t el;
  75         struct strbuf f;
  76
  77         strbuf_init(&f, from->len);
  78         strbuf_addbuf(&f, from);
  79
  80         at = strchr(f.buf, '@');
  81         if (!at) {
  82                 parse_bogus_from(from);
  83                 return;
  84         }
  85
  86         /*
  87          * If we already have one email, don't take any confusing lines
  88          */
  89         if (email.len && strchr(at + 1, '@')) {
  90                 strbuf_release(&f);
  91                 return;
  92         }
  93
  94         /* Pick up the string around '@', possibly delimited with <>
  95          * pair; that is the email part.
  96          */
  97         while (at > f.buf) {
  98                 char c = at[-1];
  99                 if (isspace(c))
 100                         break;
 101                 if (c == '<') {
 102                         at[-1] = ' ';
 103                         break;
 104                 }
 105                 at--;
 106         }
 107         el = strcspn(at, " \n\t\r\v\f>");
 108         strbuf_reset(&email);
 109         strbuf_add(&email, at, el);
 110         strbuf_remove(&f, at - f.buf, el + (at[el] ? 1 : 0));
 111
 112         /* The remainder is name.  It could be "John Doe <john.doe@xz>"
 113          * or "john.doe@xz (John Doe)", but we have removed the
 114          * email part, so trim from both ends, possibly removing
 115          * the () pair at the end.
 116          */
 117         strbuf_trim(&f);
 118         if (f.buf[0] == '(' && f.len && f.buf[f.len - 1] == ')') {
 119                 strbuf_remove(&f, 0, 1);
 120                 strbuf_setlen(&f, f.len - 1);
 121         }
 122
 123         get_sane_name(&name, &f, &email);
 124         strbuf_release(&f);
 125 }
 126
 127 static void handle_header(struct strbuf **out, const struct strbuf *line)
 128 {
 129         if (!*out) {
 130                 *out = xmalloc(sizeof(struct strbuf));
 131                 strbuf_init(*out, line->len);
 132         } else
 133                 strbuf_reset(*out);
 134
 135         strbuf_addbuf(*out, line);
 136 }
 137
 138 /* NOTE NOTE NOTE.  We do not claim we do full MIME.  We just attempt
 139  * to have enough heuristics to grok MIME encoded patches often found
 140  * on our mailing lists.  For example, we do not even treat header lines
 141  * case insensitively.
 142  */
 143
 144 static int slurp_attr(const char *line, const char *name, struct strbuf *attr)
 145 {
 146         const char *ends, *ap = strcasestr(line, name);
 147         size_t sz;
 148
 149         if (!ap) {
 150                 strbuf_setlen(attr, 0);
 151                 return 0;
 152         }
 153         ap += strlen(name);
 154         if (*ap == '"') {
 155                 ap++;
 156                 ends = "\"";
 157         }
 158         else
 159                 ends = "; \t";
 160         sz = strcspn(ap, ends);
 161         strbuf_add(attr, ap, sz);
 162         return 1;
 163 }
 164
 165 static struct strbuf *content[MAX_BOUNDARIES];
 166
 167 static struct strbuf **content_top = content;
 168
 169 static void handle_content_type(struct strbuf *line)
 170 {
 171         struct strbuf *boundary = xmalloc(sizeof(struct strbuf));
 172         strbuf_init(boundary, line->len);
 173
 174         if (!strcasestr(line->buf, "text/"))
 175                  message_type = TYPE_OTHER;
 176         if (slurp_attr(line->buf, "boundary=", boundary)) {
 177                 strbuf_insert(boundary, 0, "--", 2);
 178                 if (++content_top > &content[MAX_BOUNDARIES]) {
 179                         fprintf(stderr, "Too many boundaries to handle\n");
 180                         exit(1);
 181                 }
 182                 *content_top = boundary;
 183                 boundary = NULL;
 184         }
 185         if (slurp_attr(line->buf, "charset=", &charset))
 186                 strbuf_tolower(&charset);
 187
 188         if (boundary) {
 189                 strbuf_release(boundary);
 190                 free(boundary);
 191         }
 192 }
 193
 194 static void handle_content_transfer_encoding(const struct strbuf *line)
 195 {
 196         if (strcasestr(line->buf, "base64"))
 197                 transfer_encoding = TE_BASE64;
 198         else if (strcasestr(line->buf, "quoted-printable"))
 199                 transfer_encoding = TE_QP;
 200         else
 201                 transfer_encoding = TE_DONTCARE;
 202 }
 203
 204 static int is_multipart_boundary(const struct strbuf *line)
 205 {
 206         return (((*content_top)->len <= line->len) &&
 207                 !memcmp(line->buf, (*content_top)->buf, (*content_top)->len));
 208 }
 209
 210 static void cleanup_subject(struct strbuf *subject)
 211 {
 212         char *pos;
 213         size_t remove;
 214         while (subject->len) {
 215                 switch (*subject->buf) {
 216                 case 'r': case 'R':
 217                         if (subject->len <= 3)
 218                                 break;
 219                         if (!memcmp(subject->buf + 1, "e:", 2)) {
 220                                 strbuf_remove(subject, 0, 3);
 221                                 continue;
 222                         }
 223                         break;
 224                 case ' ': case '\t': case ':':
 225                         strbuf_remove(subject, 0, 1);
 226                         continue;
 227                 case '[':
 228                         if ((pos = strchr(subject->buf, ']'))) {
 229                                 remove = pos - subject->buf;
 230                                 if (remove <= (subject->len - remove) * 2) {
 231                                         strbuf_remove(subject, 0, remove + 1);
 232                                         continue;
 233                                 }
 234                         } else
 235                                 strbuf_remove(subject, 0, 1);
 236                         break;
 237                 }
 238                 strbuf_trim(subject);
 239                 return;
 240         }
 241 }
 242
 243 static void cleanup_space(struct strbuf *sb)
 244 {
 245         size_t pos, cnt;
 246         for (pos = 0; pos < sb->len; pos++) {
 247                 if (isspace(sb->buf[pos])) {
 248                         sb->buf[pos] = ' ';
 249                         for (cnt = 0; isspace(sb->buf[pos + cnt + 1]); cnt++);
 250                         strbuf_remove(sb, pos + 1, cnt);
 251                 }
 252         }
 253 }
 254
 255 static void decode_header(struct strbuf *line);
 256 static const char *header[MAX_HDR_PARSED] = {
 257         "From","Subject","Date",
 258 };
 259
 260 static inline int cmp_header(const struct strbuf *line, const char *hdr)
 261 {
 262         int len = strlen(hdr);
 263         return !strncasecmp(line->buf, hdr, len) && line->len > len &&
 264                         line->buf[len] == ':' && isspace(line->buf[len + 1]);
 265 }
 266
 267 static int check_header(const struct strbuf *line,
 268                                 struct strbuf *hdr_data[], int overwrite)
 269 {
 270         int i, ret = 0, len;
 271         struct strbuf sb = STRBUF_INIT;
 272         /* search for the interesting parts */
 273         for (i = 0; header[i]; i++) {
 274                 int len = strlen(header[i]);
 275                 if ((!hdr_data[i] || overwrite) && cmp_header(line, header[i])) {
 276                         /* Unwrap inline B and Q encoding, and optionally
 277                          * normalize the meta information to utf8.
 278                          */
 279                         strbuf_add(&sb, line->buf + len + 2, line->len - len - 2);
 280                         decode_header(&sb);
 281                         handle_header(&hdr_data[i], &sb);
 282                         ret = 1;
 283                         goto check_header_out;
 284                 }
 285         }
 286
 287         /* Content stuff */
 288         if (cmp_header(line, "Content-Type")) {
 289                 len = strlen("Content-Type: ");
 290                 strbuf_add(&sb, line->buf + len, line->len - len);
 291                 decode_header(&sb);
 292                 strbuf_insert(&sb, 0, "Content-Type: ", len);
 293                 handle_content_type(&sb);
 294                 ret = 1;
 295                 goto check_header_out;
 296         }
 297         if (cmp_header(line, "Content-Transfer-Encoding")) {
 298                 len = strlen("Content-Transfer-Encoding: ");
 299                 strbuf_add(&sb, line->buf + len, line->len - len);
 300                 decode_header(&sb);
 301                 handle_content_transfer_encoding(&sb);
 302                 ret = 1;
 303                 goto check_header_out;
 304         }
 305
 306         /* for inbody stuff */
 307         if (!prefixcmp(line->buf, ">From") && isspace(line->buf[5])) {
 308                 ret = 1; /* Should this return 0? */
 309                 goto check_header_out;
 310         }
 311         if (!prefixcmp(line->buf, "[PATCH]") && isspace(line->buf[7])) {
 312                 for (i = 0; header[i]; i++) {
 313                         if (!memcmp("Subject", header[i], 7)) {
 314                                 handle_header(&hdr_data[i], line);
 315                                 ret = 1;
 316                                 goto check_header_out;
 317                         }
 318                 }
 319         }
 320
 321 check_header_out:
 322         strbuf_release(&sb);
 323         return ret;
 324 }
 325
 326 static int is_rfc2822_header(const struct strbuf *line)
 327 {
 328         /*
 329          * The section that defines the loosest possible
 330          * field name is "3.6.8 Optional fields".
 331          *
 332          * optional-field = field-name ":" unstructured CRLF
 333          * field-name = 1*ftext
 334          * ftext = %d33-57 / %59-126
 335          */
 336         int ch;
 337         char *cp = line->buf;
 338
 339         /* Count mbox From headers as headers */
 340         if (!prefixcmp(cp, "From ") || !prefixcmp(cp, ">From "))
 341                 return 1;
 342
 343         while ((ch = *cp++)) {
 344                 if (ch == ':')
 345                         return 1;
 346                 if ((33 <= ch && ch <= 57) ||
 347                     (59 <= ch && ch <= 126))
 348                         continue;
 349                 break;
 350         }
 351         return 0;
 352 }
 353
 354 static int read_one_header_line(struct strbuf *line, FILE *in)
 355 {
 356         /* Get the first part of the line. */
 357         if (strbuf_getline(line, in, '\n'))
 358                 return 0;
 359
 360         /*
 361          * Is it an empty line or not a valid rfc2822 header?
 362          * If so, stop here, and return false ("not a header")
 363          */
 364         strbuf_rtrim(line);
 365         if (!line->len || !is_rfc2822_header(line)) {
 366                 /* Re-add the newline */
 367                 strbuf_addch(line, '\n');
 368                 return 0;
 369         }
 370
 371         /*
 372          * Now we need to eat all the continuation lines..
 373          * Yuck, 2822 header "folding"
 374          */
 375         for (;;) {
 376                 int peek;
 377                 struct strbuf continuation = STRBUF_INIT;
 378
 379                 peek = fgetc(in); ungetc(peek, in);
 380                 if (peek != ' ' && peek != '\t')
 381                         break;
 382                 if (strbuf_getline(&continuation, in, '\n'))
 383                         break;
 384                 continuation.buf[0] = '\n';
 385                 strbuf_rtrim(&continuation);
 386                 strbuf_addbuf(line, &continuation);
 387         }
 388
 389         return 1;
 390 }
 391
 392 static struct strbuf *decode_q_segment(const struct strbuf *q_seg, int rfc2047)
 393 {
 394         const char *in = q_seg->buf;
 395         int c;
 396         struct strbuf *out = xmalloc(sizeof(struct strbuf));
 397         strbuf_init(out, q_seg->len);
 398
 399         while ((c = *in++) != 0) {
 400                 if (c == '=') {
 401                         int d = *in++;
 402                         if (d == '\n' || !d)
 403                                 break; /* drop trailing newline */
 404                         strbuf_addch(out, (hexval(d) << 4) | hexval(*in++));
 405                         continue;
 406                 }
 407                 if (rfc2047 && c == '_') /* rfc2047 4.2 (2) */
 408                         c = 0x20;
 409                 strbuf_addch(out, c);
 410         }
 411         return out;
 412 }
 413
 414 static struct strbuf *decode_b_segment(const struct strbuf *b_seg)
 415 {
 416         /* Decode in..ep, possibly in-place to ot */
 417         int c, pos = 0, acc = 0;
 418         const char *in = b_seg->buf;
 419         struct strbuf *out = xmalloc(sizeof(struct strbuf));
 420         strbuf_init(out, b_seg->len);
 421
 422         while ((c = *in++) != 0) {
 423                 if (c == '+')
 424                         c = 62;
 425                 else if (c == '/')
 426                         c = 63;
 427                 else if ('A' <= c && c <= 'Z')
 428                         c -= 'A';
 429                 else if ('a' <= c && c <= 'z')
 430                         c -= 'a' - 26;
 431                 else if ('0' <= c && c <= '9')
 432                         c -= '0' - 52;
 433                 else
 434                         continue; /* garbage */
 435                 switch (pos++) {
 436                 case 0:
 437                         acc = (c << 2);
 438                         break;
 439                 case 1:
 440                         strbuf_addch(out, (acc | (c >> 4)));
 441                         acc = (c & 15) << 4;
 442                         break;
 443                 case 2:
 444                         strbuf_addch(out, (acc | (c >> 2)));
 445                         acc = (c & 3) << 6;
 446                         break;
 447                 case 3:
 448                         strbuf_addch(out, (acc | c));
 449                         acc = pos = 0;
 450                         break;
 451                 }
 452         }
 453         return out;
 454 }
 455
 456 /*
 457  * When there is no known charset, guess.
 458  *
 459  * Right now we assume that if the target is UTF-8 (the default),
 460  * and it already looks like UTF-8 (which includes US-ASCII as its
 461  * subset, of course) then that is what it is and there is nothing
 462  * to do.
 463  *
 464  * Otherwise, we default to assuming it is Latin1 for historical
 465  * reasons.
 466  */
 467 static const char *guess_charset(const struct strbuf *line, const char *target_charset)
 468 {
 469         if (is_encoding_utf8(target_charset)) {
 470                 if (is_utf8(line->buf))
 471                         return NULL;
 472         }
 473         return "latin1";
 474 }
 475
 476 static void convert_to_utf8(struct strbuf *line, const char *charset)
 477 {
 478         char *out;
 479
 480         if (!charset || !*charset) {
 481                 charset = guess_charset(line, metainfo_charset);
 482                 if (!charset)
 483                         return;
 484         }
 485
 486         if (!strcmp(metainfo_charset, charset))
 487                 return;
 488         out = reencode_string(line->buf, metainfo_charset, charset);
 489         if (!out)
 490                 die("cannot convert from %s to %s\n",
 491                     charset, metainfo_charset);
 492         strbuf_attach(line, out, strlen(out), strlen(out));
 493 }
 494
 495 static int decode_header_bq(struct strbuf *it)
 496 {
 497         char *in, *ep, *cp;
 498         struct strbuf outbuf = STRBUF_INIT, *dec;
 499         struct strbuf charset_q = STRBUF_INIT, piecebuf = STRBUF_INIT;
 500         int rfc2047 = 0;
 501
 502         in = it->buf;
 503         while (in - it->buf <= it->len && (ep = strstr(in, "=?")) != NULL) {
 504                 int encoding;
 505                 strbuf_reset(&charset_q);
 506                 strbuf_reset(&piecebuf);
 507                 rfc2047 = 1;
 508
 509                 if (in != ep) {
 510                         /*
 511                          * We are about to process an encoded-word
 512                          * that begins at ep, but there is something
 513                          * before the encoded word.
 514                          */
 515                         char *scan;
 516                         for (scan = in; scan < ep; scan++)
 517                                 if (!isspace(*scan))
 518                                         break;
 519
 520                         if (scan != ep || in == it->buf) {
 521                                 /*
 522                                  * We should not lose that "something",
 523                                  * unless we have just processed an
 524                                  * encoded-word, and there is only LWS
 525                                  * before the one we are about to process.
 526                                  */
 527                                 strbuf_add(&outbuf, in, ep - in);
 528                         }
 529                         in = ep;
 530                 }
 531                 /* E.g.
 532                  * ep : "=?iso-2022-jp?B?GyR...?= foo"
 533                  * ep : "=?ISO-8859-1?Q?Foo=FCbar?= baz"
 534                  */
 535                 ep += 2;
 536
 537                 if (ep - it->buf >= it->len || !(cp = strchr(ep, '?')))
 538                         goto decode_header_bq_out;
 539
 540                 if (cp + 3 - it->buf > it->len)
 541                         goto decode_header_bq_out;
 542                 strbuf_add(&charset_q, ep, cp - ep);
 543                 strbuf_tolower(&charset_q);
 544
 545                 encoding = cp[1];
 546                 if (!encoding || cp[2] != '?')
 547                         goto decode_header_bq_out;
 548                 ep = strstr(cp + 3, "?=");
 549                 if (!ep)
 550                         goto decode_header_bq_out;
 551                 strbuf_add(&piecebuf, cp + 3, ep - cp - 3);
 552                 switch (tolower(encoding)) {
 553                 default:
 554                         goto decode_header_bq_out;
 555                 case 'b':
 556                         dec = decode_b_segment(&piecebuf);
 557                         break;
 558                 case 'q':
 559                         dec = decode_q_segment(&piecebuf, 1);
 560                         break;
 561                 }
 562                 if (metainfo_charset)
 563                         convert_to_utf8(dec, charset_q.buf);
 564
 565                 strbuf_addbuf(&outbuf, dec);
 566                 strbuf_release(dec);
 567                 free(dec);
 568                 in = ep + 2;
 569         }
 570         strbuf_addstr(&outbuf, in);
 571         strbuf_reset(it);
 572         strbuf_addbuf(it, &outbuf);
 573 decode_header_bq_out:
 574         strbuf_release(&outbuf);
 575         strbuf_release(&charset_q);
 576         strbuf_release(&piecebuf);
 577         return rfc2047;
 578 }
 579
 580 static void decode_header(struct strbuf *it)
 581 {
 582         if (decode_header_bq(it))
 583                 return;
 584         /* otherwise "it" is a straight copy of the input.
 585          * This can be binary guck but there is no charset specified.
 586          */
 587         if (metainfo_charset)
 588                 convert_to_utf8(it, "");
 589 }
 590
 591 static void decode_transfer_encoding(struct strbuf *line)
 592 {
 593         struct strbuf *ret;
 594
 595         switch (transfer_encoding) {
 596         case TE_QP:
 597                 ret = decode_q_segment(line, 0);
 598                 break;
 599         case TE_BASE64:
 600                 ret = decode_b_segment(line);
 601                 break;
 602         case TE_DONTCARE:
 603         default:
 604                 return;
 605         }
 606         strbuf_reset(line);
 607         strbuf_addbuf(line, ret);
 608         strbuf_release(ret);
 609         free(ret);
 610 }
 611
 612 static void handle_filter(struct strbuf *line);
 613
 614 static int find_boundary(void)
 615 {
 616         while (!strbuf_getline(&line, fin, '\n')) {
 617                 if (*content_top && is_multipart_boundary(&line))
 618                         return 1;
 619         }
 620         return 0;
 621 }
 622
 623 static int handle_boundary(void)
 624 {
 625         struct strbuf newline = STRBUF_INIT;
 626
 627         strbuf_addch(&newline, '\n');
 628 again:
 629         if (line.len >= (*content_top)->len + 2 &&
 630             !memcmp(line.buf + (*content_top)->len, "--", 2)) {
 631                 /* we hit an end boundary */
 632                 /* pop the current boundary off the stack */
 633                 strbuf_release(*content_top);
 634                 free(*content_top);
 635                 *content_top = NULL;
 636
 637                 /* technically won't happen as is_multipart_boundary()
 638                    will fail first.  But just in case..
 639                  */
 640                 if (--content_top < content) {
 641                         fprintf(stderr, "Detected mismatched boundaries, "
 642                                         "can't recover\n");
 643                         exit(1);
 644                 }
 645                 handle_filter(&newline);
 646                 strbuf_release(&newline);
 647
 648                 /* skip to the next boundary */
 649                 if (!find_boundary())
 650                         return 0;
 651                 goto again;
 652         }
 653
 654         /* set some defaults */
 655         transfer_encoding = TE_DONTCARE;
 656         strbuf_reset(&charset);
 657         message_type = TYPE_TEXT;
 658
 659         /* slurp in this section's info */
 660         while (read_one_header_line(&line, fin))
 661                 check_header(&line, p_hdr_data, 0);
 662
 663         strbuf_release(&newline);
 664         /* replenish line */
 665         if (strbuf_getline(&line, fin, '\n'))
 666                 return 0;
 667         strbuf_addch(&line, '\n');
 668         return 1;
 669 }
 670
 671 static inline int patchbreak(const struct strbuf *line)
 672 {
 673         size_t i;
 674
 675         /* Beginning of a "diff -" header? */
 676         if (!prefixcmp(line->buf, "diff -"))
 677                 return 1;
 678
 679         /* CVS "Index: " line? */
 680         if (!prefixcmp(line->buf, "Index: "))
 681                 return 1;
 682
 683         /*
 684          * "--- <filename>" starts patches without headers
 685          * "---<sp>*" is a manual separator
 686          */
 687         if (line->len < 4)
 688                 return 0;
 689
 690         if (!prefixcmp(line->buf, "---")) {
 691                 /* space followed by a filename? */
 692                 if (line->buf[3] == ' ' && !isspace(line->buf[4]))
 693                         return 1;
 694                 /* Just whitespace? */
 695                 for (i = 3; i < line->len; i++) {
 696                         unsigned char c = line->buf[i];
 697                         if (c == '\n')
 698                                 return 1;
 699                         if (!isspace(c))
 700                                 break;
 701                 }
 702                 return 0;
 703         }
 704         return 0;
 705 }
 706
 707 static int handle_commit_msg(struct strbuf *line)
 708 {
 709         static int still_looking = 1;
 710
 711         if (!cmitmsg)
 712                 return 0;
 713
 714         if (still_looking) {
 715                 strbuf_ltrim(line);
 716                 if (!line->len)
 717                         return 0;
 718                 if ((still_looking = check_header(line, s_hdr_data, 0)) != 0)
 719                         return 0;
 720         }
 721
 722         /* normalize the log message to UTF-8. */
 723         if (metainfo_charset)
 724                 convert_to_utf8(line, charset.buf);
 725
 726         if (patchbreak(line)) {
 727                 fclose(cmitmsg);
 728                 cmitmsg = NULL;
 729                 return 1;
 730         }
 731
 732         fputs(line->buf, cmitmsg);
 733         return 0;
 734 }
 735
 736 static void handle_patch(const struct strbuf *line)
 737 {
 738         fwrite(line->buf, 1, line->len, patchfile);
 739         patch_lines++;
 740 }
 741
 742 static void handle_filter(struct strbuf *line)
 743 {
 744         static int filter = 0;
 745
 746         /* filter tells us which part we left off on */
 747         switch (filter) {
 748         case 0:
 749                 if (!handle_commit_msg(line))
 750                         break;
 751                 filter++;
 752         case 1:
 753                 handle_patch(line);
 754                 break;
 755         }
 756 }
 757
 758 static void handle_body(void)
 759 {
 760         int len = 0;
 761         struct strbuf prev = STRBUF_INIT;
 762
 763         /* Skip up to the first boundary */
 764         if (*content_top) {
 765                 if (!find_boundary())
 766                         goto handle_body_out;
 767         }
 768
 769         do {
 770                 strbuf_setlen(&line, line.len + len);
 771
 772                 /* process any boundary lines */
 773                 if (*content_top && is_multipart_boundary(&line)) {
 774                         /* flush any leftover */
 775                         if (prev.len) {
 776                                 handle_filter(&prev);
 777                                 strbuf_reset(&prev);
 778                         }
 779                         if (!handle_boundary())
 780                                 goto handle_body_out;
 781                 }
 782
 783                 /* Unwrap transfer encoding */
 784                 decode_transfer_encoding(&line);
 785
 786                 switch (transfer_encoding) {
 787                 case TE_BASE64:
 788                 case TE_QP:
 789                 {
 790                         struct strbuf **lines, **it, *sb;
 791
 792                         /* Prepend any previous partial lines */
 793                         strbuf_insert(&line, 0, prev.buf, prev.len);
 794                         strbuf_reset(&prev);
 795
 796                         /* binary data most likely doesn't have newlines */
 797                         if (message_type != TYPE_TEXT) {
 798                                 handle_filter(&line);
 799                                 break;
 800                         }
 801                         /*
 802                          * This is a decoded line that may contain
 803                          * multiple new lines.  Pass only one chunk
 804                          * at a time to handle_filter()
 805                          */
 806                         lines = strbuf_split(&line, '\n');
 807                         for (it = lines; (sb = *it); it++) {
 808                                 if (*(it + 1) == NULL) /* The last line */
 809                                         if (sb->buf[sb->len - 1] != '\n') {
 810                                                 /* Partial line, save it for later. */
 811                                                 strbuf_addbuf(&prev, sb);
 812                                                 break;
 813                                         }
 814                                 handle_filter(sb);
 815                         }
 816                         /*
 817                          * The partial chunk is saved in "prev" and will be
 818                          * appended by the next iteration of read_line_with_nul().
 819                          */
 820                         strbuf_list_free(lines);
 821                         break;
 822                 }
 823                 default:
 824                         handle_filter(&line);
 825                 }
 826
 827                 strbuf_reset(&line);
 828                 if (strbuf_avail(&line) < 100)
 829                         strbuf_grow(&line, 100);
 830         } while ((len = read_line_with_nul(line.buf, strbuf_avail(&line), fin)));
 831
 832 handle_body_out:
 833         strbuf_release(&prev);
 834 }
 835
 836 static void output_header_lines(FILE *fout, const char *hdr, const struct strbuf *data)
 837 {
 838         const char *sp = data->buf;
 839         while (1) {
 840                 char *ep = strchr(sp, '\n');
 841                 int len;
 842                 if (!ep)
 843                         len = strlen(sp);
 844                 else
 845                         len = ep - sp;
 846                 fprintf(fout, "%s: %.*s\n", hdr, len, sp);
 847                 if (!ep)
 848                         break;
 849                 sp = ep + 1;
 850         }
 851 }
 852
 853 static void handle_info(void)
 854 {
 855         struct strbuf *hdr;
 856         int i;
 857
 858         for (i = 0; header[i]; i++) {
 859                 /* only print inbody headers if we output a patch file */
 860                 if (patch_lines && s_hdr_data[i])
 861                         hdr = s_hdr_data[i];
 862                 else if (p_hdr_data[i])
 863                         hdr = p_hdr_data[i];
 864                 else
 865                         continue;
 866
 867                 if (!memcmp(header[i], "Subject", 7)) {
 868                         if (!keep_subject) {
 869                                 cleanup_subject(hdr);
 870                                 cleanup_space(hdr);
 871                         }
 872                         output_header_lines(fout, "Subject", hdr);
 873                 } else if (!memcmp(header[i], "From", 4)) {
 874                         cleanup_space(hdr);
 875                         handle_from(hdr);
 876                         fprintf(fout, "Author: %s\n", name.buf);
 877                         fprintf(fout, "Email: %s\n", email.buf);
 878                 } else {
 879                         cleanup_space(hdr);
 880                         fprintf(fout, "%s: %s\n", header[i], hdr->buf);
 881                 }
 882         }
 883         fprintf(fout, "\n");
 884 }
 885
 886 static int mailinfo(FILE *in, FILE *out, int ks, const char *encoding,
 887                     const char *msg, const char *patch)
 888 {
 889         int peek;
 890         keep_subject = ks;
 891         metainfo_charset = encoding;
 892         fin = in;
 893         fout = out;
 894
 895         cmitmsg = fopen(msg, "w");
 896         if (!cmitmsg) {
 897                 perror(msg);
 898                 return -1;
 899         }
 900         patchfile = fopen(patch, "w");
 901         if (!patchfile) {
 902                 perror(patch);
 903                 fclose(cmitmsg);
 904                 return -1;
 905         }
 906
 907         p_hdr_data = xcalloc(MAX_HDR_PARSED, sizeof(*p_hdr_data));
 908         s_hdr_data = xcalloc(MAX_HDR_PARSED, sizeof(*s_hdr_data));
 909
 910         do {
 911                 peek = fgetc(in);
 912         } while (isspace(peek));
 913         ungetc(peek, in);
 914
 915         /* process the email header */
 916         while (read_one_header_line(&line, fin))
 917                 check_header(&line, p_hdr_data, 1);
 918
 919         handle_body();
 920         handle_info();
 921
 922         return 0;
 923 }
 924
 925 static const char mailinfo_usage[] =
 926         "git mailinfo [-k] [-u | --encoding=<encoding> | -n] msg patch <mail >info";
 927
 928 int cmd_mailinfo(int argc, const char **argv, const char *prefix)
 929 {
 930         const char *def_charset;
 931
 932         /* NEEDSWORK: might want to do the optional .git/ directory
 933          * discovery
 934          */
 935         git_config(git_default_config, NULL);
 936
 937         def_charset = (git_commit_encoding ? git_commit_encoding : "utf-8");
 938         metainfo_charset = def_charset;
 939
 940         while (1 < argc && argv[1][0] == '-') {
 941                 if (!strcmp(argv[1], "-k"))
 942                         keep_subject = 1;
 943                 else if (!strcmp(argv[1], "-u"))
 944                         metainfo_charset = def_charset;
 945                 else if (!strcmp(argv[1], "-n"))
 946                         metainfo_charset = NULL;
 947                 else if (!prefixcmp(argv[1], "--encoding="))
 948                         metainfo_charset = argv[1] + 11;
 949                 else
 950                         usage(mailinfo_usage);
 951                 argc--; argv++;
 952         }
 953
 954         if (argc != 3)
 955                 usage(mailinfo_usage);
 956
 957         return !!mailinfo(stdin, stdout, keep_subject, metainfo_charset, argv[1], argv[2]);
 958 }