builtin-mailinfo.con commit Update draft release notes to 1.6.6 before merging topics for -rc1 (66abce0)
   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
  10static FILE *cmitmsg, *patchfile, *fin, *fout;
  11
  12static int keep_subject;
  13static const char *metainfo_charset;
  14static struct strbuf line = STRBUF_INIT;
  15static struct strbuf name = STRBUF_INIT;
  16static struct strbuf email = STRBUF_INIT;
  17
  18static enum  {
  19        TE_DONTCARE, TE_QP, TE_BASE64,
  20} transfer_encoding;
  21static enum  {
  22        TYPE_TEXT, TYPE_OTHER,
  23} message_type;
  24
  25static struct strbuf charset = STRBUF_INIT;
  26static int patch_lines;
  27static struct strbuf **p_hdr_data, **s_hdr_data;
  28static int use_scissors;
  29static int use_inbody_headers = 1;
  30
  31#define MAX_HDR_PARSED 10
  32#define MAX_BOUNDARIES 5
  33
  34static void cleanup_space(struct strbuf *sb);
  35
  36
  37static void get_sane_name(struct strbuf *out, struct strbuf *name, struct strbuf *email)
  38{
  39        struct strbuf *src = name;
  40        if (name->len < 3 || 60 < name->len || strchr(name->buf, '@') ||
  41                strchr(name->buf, '<') || strchr(name->buf, '>'))
  42                src = email;
  43        else if (name == out)
  44                return;
  45        strbuf_reset(out);
  46        strbuf_addbuf(out, src);
  47}
  48
  49static void parse_bogus_from(const struct strbuf *line)
  50{
  51        /* John Doe <johndoe> */
  52
  53        char *bra, *ket;
  54        /* This is fallback, so do not bother if we already have an
  55         * e-mail address.
  56         */
  57        if (email.len)
  58                return;
  59
  60        bra = strchr(line->buf, '<');
  61        if (!bra)
  62                return;
  63        ket = strchr(bra, '>');
  64        if (!ket)
  65                return;
  66
  67        strbuf_reset(&email);
  68        strbuf_add(&email, bra + 1, ket - bra - 1);
  69
  70        strbuf_reset(&name);
  71        strbuf_add(&name, line->buf, bra - line->buf);
  72        strbuf_trim(&name);
  73        get_sane_name(&name, &name, &email);
  74}
  75
  76static void handle_from(const struct strbuf *from)
  77{
  78        char *at;
  79        size_t el;
  80        struct strbuf f;
  81
  82        strbuf_init(&f, from->len);
  83        strbuf_addbuf(&f, from);
  84
  85        at = strchr(f.buf, '@');
  86        if (!at) {
  87                parse_bogus_from(from);
  88                return;
  89        }
  90
  91        /*
  92         * If we already have one email, don't take any confusing lines
  93         */
  94        if (email.len && strchr(at + 1, '@')) {
  95                strbuf_release(&f);
  96                return;
  97        }
  98
  99        /* Pick up the string around '@', possibly delimited with <>
 100         * pair; that is the email part.
 101         */
 102        while (at > f.buf) {
 103                char c = at[-1];
 104                if (isspace(c))
 105                        break;
 106                if (c == '<') {
 107                        at[-1] = ' ';
 108                        break;
 109                }
 110                at--;
 111        }
 112        el = strcspn(at, " \n\t\r\v\f>");
 113        strbuf_reset(&email);
 114        strbuf_add(&email, at, el);
 115        strbuf_remove(&f, at - f.buf, el + (at[el] ? 1 : 0));
 116
 117        /* The remainder is name.  It could be
 118         *
 119         * - "John Doe <john.doe@xz>"                   (a), or
 120         * - "john.doe@xz (John Doe)"                   (b), or
 121         * - "John (zzz) Doe <john.doe@xz> (Comment)"   (c)
 122         *
 123         * but we have removed the email part, so
 124         *
 125         * - remove extra spaces which could stay after email (case 'c'), and
 126         * - trim from both ends, possibly removing the () pair at the end
 127         *   (cases 'a' and 'b').
 128         */
 129        cleanup_space(&f);
 130        strbuf_trim(&f);
 131        if (f.buf[0] == '(' && f.len && f.buf[f.len - 1] == ')') {
 132                strbuf_remove(&f, 0, 1);
 133                strbuf_setlen(&f, f.len - 1);
 134        }
 135
 136        get_sane_name(&name, &f, &email);
 137        strbuf_release(&f);
 138}
 139
 140static void handle_header(struct strbuf **out, const struct strbuf *line)
 141{
 142        if (!*out) {
 143                *out = xmalloc(sizeof(struct strbuf));
 144                strbuf_init(*out, line->len);
 145        } else
 146                strbuf_reset(*out);
 147
 148        strbuf_addbuf(*out, line);
 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
 157static int slurp_attr(const char *line, const char *name, struct strbuf *attr)
 158{
 159        const char *ends, *ap = strcasestr(line, name);
 160        size_t sz;
 161
 162        if (!ap) {
 163                strbuf_setlen(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        strbuf_add(attr, ap, sz);
 175        return 1;
 176}
 177
 178static struct strbuf *content[MAX_BOUNDARIES];
 179
 180static struct strbuf **content_top = content;
 181
 182static void handle_content_type(struct strbuf *line)
 183{
 184        struct strbuf *boundary = xmalloc(sizeof(struct strbuf));
 185        strbuf_init(boundary, line->len);
 186
 187        if (!strcasestr(line->buf, "text/"))
 188                 message_type = TYPE_OTHER;
 189        if (slurp_attr(line->buf, "boundary=", boundary)) {
 190                strbuf_insert(boundary, 0, "--", 2);
 191                if (++content_top > &content[MAX_BOUNDARIES]) {
 192                        fprintf(stderr, "Too many boundaries to handle\n");
 193                        exit(1);
 194                }
 195                *content_top = boundary;
 196                boundary = NULL;
 197        }
 198        slurp_attr(line->buf, "charset=", &charset);
 199
 200        if (boundary) {
 201                strbuf_release(boundary);
 202                free(boundary);
 203        }
 204}
 205
 206static void handle_content_transfer_encoding(const struct strbuf *line)
 207{
 208        if (strcasestr(line->buf, "base64"))
 209                transfer_encoding = TE_BASE64;
 210        else if (strcasestr(line->buf, "quoted-printable"))
 211                transfer_encoding = TE_QP;
 212        else
 213                transfer_encoding = TE_DONTCARE;
 214}
 215
 216static int is_multipart_boundary(const struct strbuf *line)
 217{
 218        return (((*content_top)->len <= line->len) &&
 219                !memcmp(line->buf, (*content_top)->buf, (*content_top)->len));
 220}
 221
 222static void cleanup_subject(struct strbuf *subject)
 223{
 224        char *pos;
 225        size_t remove;
 226        while (subject->len) {
 227                switch (*subject->buf) {
 228                case 'r': case 'R':
 229                        if (subject->len <= 3)
 230                                break;
 231                        if (!memcmp(subject->buf + 1, "e:", 2)) {
 232                                strbuf_remove(subject, 0, 3);
 233                                continue;
 234                        }
 235                        break;
 236                case ' ': case '\t': case ':':
 237                        strbuf_remove(subject, 0, 1);
 238                        continue;
 239                case '[':
 240                        if ((pos = strchr(subject->buf, ']'))) {
 241                                remove = pos - subject->buf;
 242                                if (remove <= (subject->len - remove) * 2) {
 243                                        strbuf_remove(subject, 0, remove + 1);
 244                                        continue;
 245                                }
 246                        } else
 247                                strbuf_remove(subject, 0, 1);
 248                        break;
 249                }
 250                strbuf_trim(subject);
 251                return;
 252        }
 253}
 254
 255static void cleanup_space(struct strbuf *sb)
 256{
 257        size_t pos, cnt;
 258        for (pos = 0; pos < sb->len; pos++) {
 259                if (isspace(sb->buf[pos])) {
 260                        sb->buf[pos] = ' ';
 261                        for (cnt = 0; isspace(sb->buf[pos + cnt + 1]); cnt++);
 262                        strbuf_remove(sb, pos + 1, cnt);
 263                }
 264        }
 265}
 266
 267static void decode_header(struct strbuf *line);
 268static const char *header[MAX_HDR_PARSED] = {
 269        "From","Subject","Date",
 270};
 271
 272static inline int cmp_header(const struct strbuf *line, const char *hdr)
 273{
 274        int len = strlen(hdr);
 275        return !strncasecmp(line->buf, hdr, len) && line->len > len &&
 276                        line->buf[len] == ':' && isspace(line->buf[len + 1]);
 277}
 278
 279static int check_header(const struct strbuf *line,
 280                                struct strbuf *hdr_data[], int overwrite)
 281{
 282        int i, ret = 0, len;
 283        struct strbuf sb = STRBUF_INIT;
 284        /* search for the interesting parts */
 285        for (i = 0; header[i]; i++) {
 286                int len = strlen(header[i]);
 287                if ((!hdr_data[i] || overwrite) && cmp_header(line, header[i])) {
 288                        /* Unwrap inline B and Q encoding, and optionally
 289                         * normalize the meta information to utf8.
 290                         */
 291                        strbuf_add(&sb, line->buf + len + 2, line->len - len - 2);
 292                        decode_header(&sb);
 293                        handle_header(&hdr_data[i], &sb);
 294                        ret = 1;
 295                        goto check_header_out;
 296                }
 297        }
 298
 299        /* Content stuff */
 300        if (cmp_header(line, "Content-Type")) {
 301                len = strlen("Content-Type: ");
 302                strbuf_add(&sb, line->buf + len, line->len - len);
 303                decode_header(&sb);
 304                strbuf_insert(&sb, 0, "Content-Type: ", len);
 305                handle_content_type(&sb);
 306                ret = 1;
 307                goto check_header_out;
 308        }
 309        if (cmp_header(line, "Content-Transfer-Encoding")) {
 310                len = strlen("Content-Transfer-Encoding: ");
 311                strbuf_add(&sb, line->buf + len, line->len - len);
 312                decode_header(&sb);
 313                handle_content_transfer_encoding(&sb);
 314                ret = 1;
 315                goto check_header_out;
 316        }
 317
 318        /* for inbody stuff */
 319        if (!prefixcmp(line->buf, ">From") && isspace(line->buf[5])) {
 320                ret = 1; /* Should this return 0? */
 321                goto check_header_out;
 322        }
 323        if (!prefixcmp(line->buf, "[PATCH]") && isspace(line->buf[7])) {
 324                for (i = 0; header[i]; i++) {
 325                        if (!memcmp("Subject", header[i], 7)) {
 326                                handle_header(&hdr_data[i], line);
 327                                ret = 1;
 328                                goto check_header_out;
 329                        }
 330                }
 331        }
 332
 333check_header_out:
 334        strbuf_release(&sb);
 335        return ret;
 336}
 337
 338static int is_rfc2822_header(const struct strbuf *line)
 339{
 340        /*
 341         * The section that defines the loosest possible
 342         * field name is "3.6.8 Optional fields".
 343         *
 344         * optional-field = field-name ":" unstructured CRLF
 345         * field-name = 1*ftext
 346         * ftext = %d33-57 / %59-126
 347         */
 348        int ch;
 349        char *cp = line->buf;
 350
 351        /* Count mbox From headers as headers */
 352        if (!prefixcmp(cp, "From ") || !prefixcmp(cp, ">From "))
 353                return 1;
 354
 355        while ((ch = *cp++)) {
 356                if (ch == ':')
 357                        return 1;
 358                if ((33 <= ch && ch <= 57) ||
 359                    (59 <= ch && ch <= 126))
 360                        continue;
 361                break;
 362        }
 363        return 0;
 364}
 365
 366static int read_one_header_line(struct strbuf *line, FILE *in)
 367{
 368        /* Get the first part of the line. */
 369        if (strbuf_getline(line, in, '\n'))
 370                return 0;
 371
 372        /*
 373         * Is it an empty line or not a valid rfc2822 header?
 374         * If so, stop here, and return false ("not a header")
 375         */
 376        strbuf_rtrim(line);
 377        if (!line->len || !is_rfc2822_header(line)) {
 378                /* Re-add the newline */
 379                strbuf_addch(line, '\n');
 380                return 0;
 381        }
 382
 383        /*
 384         * Now we need to eat all the continuation lines..
 385         * Yuck, 2822 header "folding"
 386         */
 387        for (;;) {
 388                int peek;
 389                struct strbuf continuation = STRBUF_INIT;
 390
 391                peek = fgetc(in); ungetc(peek, in);
 392                if (peek != ' ' && peek != '\t')
 393                        break;
 394                if (strbuf_getline(&continuation, in, '\n'))
 395                        break;
 396                continuation.buf[0] = '\n';
 397                strbuf_rtrim(&continuation);
 398                strbuf_addbuf(line, &continuation);
 399        }
 400
 401        return 1;
 402}
 403
 404static struct strbuf *decode_q_segment(const struct strbuf *q_seg, int rfc2047)
 405{
 406        const char *in = q_seg->buf;
 407        int c;
 408        struct strbuf *out = xmalloc(sizeof(struct strbuf));
 409        strbuf_init(out, q_seg->len);
 410
 411        while ((c = *in++) != 0) {
 412                if (c == '=') {
 413                        int d = *in++;
 414                        if (d == '\n' || !d)
 415                                break; /* drop trailing newline */
 416                        strbuf_addch(out, (hexval(d) << 4) | hexval(*in++));
 417                        continue;
 418                }
 419                if (rfc2047 && c == '_') /* rfc2047 4.2 (2) */
 420                        c = 0x20;
 421                strbuf_addch(out, c);
 422        }
 423        return out;
 424}
 425
 426static struct strbuf *decode_b_segment(const struct strbuf *b_seg)
 427{
 428        /* Decode in..ep, possibly in-place to ot */
 429        int c, pos = 0, acc = 0;
 430        const char *in = b_seg->buf;
 431        struct strbuf *out = xmalloc(sizeof(struct strbuf));
 432        strbuf_init(out, b_seg->len);
 433
 434        while ((c = *in++) != 0) {
 435                if (c == '+')
 436                        c = 62;
 437                else if (c == '/')
 438                        c = 63;
 439                else if ('A' <= c && c <= 'Z')
 440                        c -= 'A';
 441                else if ('a' <= c && c <= 'z')
 442                        c -= 'a' - 26;
 443                else if ('0' <= c && c <= '9')
 444                        c -= '0' - 52;
 445                else
 446                        continue; /* garbage */
 447                switch (pos++) {
 448                case 0:
 449                        acc = (c << 2);
 450                        break;
 451                case 1:
 452                        strbuf_addch(out, (acc | (c >> 4)));
 453                        acc = (c & 15) << 4;
 454                        break;
 455                case 2:
 456                        strbuf_addch(out, (acc | (c >> 2)));
 457                        acc = (c & 3) << 6;
 458                        break;
 459                case 3:
 460                        strbuf_addch(out, (acc | c));
 461                        acc = pos = 0;
 462                        break;
 463                }
 464        }
 465        return out;
 466}
 467
 468/*
 469 * When there is no known charset, guess.
 470 *
 471 * Right now we assume that if the target is UTF-8 (the default),
 472 * and it already looks like UTF-8 (which includes US-ASCII as its
 473 * subset, of course) then that is what it is and there is nothing
 474 * to do.
 475 *
 476 * Otherwise, we default to assuming it is Latin1 for historical
 477 * reasons.
 478 */
 479static const char *guess_charset(const struct strbuf *line, const char *target_charset)
 480{
 481        if (is_encoding_utf8(target_charset)) {
 482                if (is_utf8(line->buf))
 483                        return NULL;
 484        }
 485        return "ISO8859-1";
 486}
 487
 488static void convert_to_utf8(struct strbuf *line, const char *charset)
 489{
 490        char *out;
 491
 492        if (!charset || !*charset) {
 493                charset = guess_charset(line, metainfo_charset);
 494                if (!charset)
 495                        return;
 496        }
 497
 498        if (!strcasecmp(metainfo_charset, charset))
 499                return;
 500        out = reencode_string(line->buf, metainfo_charset, charset);
 501        if (!out)
 502                die("cannot convert from %s to %s",
 503                    charset, metainfo_charset);
 504        strbuf_attach(line, out, strlen(out), strlen(out));
 505}
 506
 507static int decode_header_bq(struct strbuf *it)
 508{
 509        char *in, *ep, *cp;
 510        struct strbuf outbuf = STRBUF_INIT, *dec;
 511        struct strbuf charset_q = STRBUF_INIT, piecebuf = STRBUF_INIT;
 512        int rfc2047 = 0;
 513
 514        in = it->buf;
 515        while (in - it->buf <= it->len && (ep = strstr(in, "=?")) != NULL) {
 516                int encoding;
 517                strbuf_reset(&charset_q);
 518                strbuf_reset(&piecebuf);
 519                rfc2047 = 1;
 520
 521                if (in != ep) {
 522                        /*
 523                         * We are about to process an encoded-word
 524                         * that begins at ep, but there is something
 525                         * before the encoded word.
 526                         */
 527                        char *scan;
 528                        for (scan = in; scan < ep; scan++)
 529                                if (!isspace(*scan))
 530                                        break;
 531
 532                        if (scan != ep || in == it->buf) {
 533                                /*
 534                                 * We should not lose that "something",
 535                                 * unless we have just processed an
 536                                 * encoded-word, and there is only LWS
 537                                 * before the one we are about to process.
 538                                 */
 539                                strbuf_add(&outbuf, in, ep - in);
 540                        }
 541                }
 542                /* E.g.
 543                 * ep : "=?iso-2022-jp?B?GyR...?= foo"
 544                 * ep : "=?ISO-8859-1?Q?Foo=FCbar?= baz"
 545                 */
 546                ep += 2;
 547
 548                if (ep - it->buf >= it->len || !(cp = strchr(ep, '?')))
 549                        goto decode_header_bq_out;
 550
 551                if (cp + 3 - it->buf > it->len)
 552                        goto decode_header_bq_out;
 553                strbuf_add(&charset_q, ep, cp - ep);
 554
 555                encoding = cp[1];
 556                if (!encoding || cp[2] != '?')
 557                        goto decode_header_bq_out;
 558                ep = strstr(cp + 3, "?=");
 559                if (!ep)
 560                        goto decode_header_bq_out;
 561                strbuf_add(&piecebuf, cp + 3, ep - cp - 3);
 562                switch (tolower(encoding)) {
 563                default:
 564                        goto decode_header_bq_out;
 565                case 'b':
 566                        dec = decode_b_segment(&piecebuf);
 567                        break;
 568                case 'q':
 569                        dec = decode_q_segment(&piecebuf, 1);
 570                        break;
 571                }
 572                if (metainfo_charset)
 573                        convert_to_utf8(dec, charset_q.buf);
 574
 575                strbuf_addbuf(&outbuf, dec);
 576                strbuf_release(dec);
 577                free(dec);
 578                in = ep + 2;
 579        }
 580        strbuf_addstr(&outbuf, in);
 581        strbuf_reset(it);
 582        strbuf_addbuf(it, &outbuf);
 583decode_header_bq_out:
 584        strbuf_release(&outbuf);
 585        strbuf_release(&charset_q);
 586        strbuf_release(&piecebuf);
 587        return rfc2047;
 588}
 589
 590static void decode_header(struct strbuf *it)
 591{
 592        if (decode_header_bq(it))
 593                return;
 594        /* otherwise "it" is a straight copy of the input.
 595         * This can be binary guck but there is no charset specified.
 596         */
 597        if (metainfo_charset)
 598                convert_to_utf8(it, "");
 599}
 600
 601static void decode_transfer_encoding(struct strbuf *line)
 602{
 603        struct strbuf *ret;
 604
 605        switch (transfer_encoding) {
 606        case TE_QP:
 607                ret = decode_q_segment(line, 0);
 608                break;
 609        case TE_BASE64:
 610                ret = decode_b_segment(line);
 611                break;
 612        case TE_DONTCARE:
 613        default:
 614                return;
 615        }
 616        strbuf_reset(line);
 617        strbuf_addbuf(line, ret);
 618        strbuf_release(ret);
 619        free(ret);
 620}
 621
 622static void handle_filter(struct strbuf *line);
 623
 624static int find_boundary(void)
 625{
 626        while (!strbuf_getline(&line, fin, '\n')) {
 627                if (*content_top && is_multipart_boundary(&line))
 628                        return 1;
 629        }
 630        return 0;
 631}
 632
 633static int handle_boundary(void)
 634{
 635        struct strbuf newline = STRBUF_INIT;
 636
 637        strbuf_addch(&newline, '\n');
 638again:
 639        if (line.len >= (*content_top)->len + 2 &&
 640            !memcmp(line.buf + (*content_top)->len, "--", 2)) {
 641                /* we hit an end boundary */
 642                /* pop the current boundary off the stack */
 643                strbuf_release(*content_top);
 644                free(*content_top);
 645                *content_top = NULL;
 646
 647                /* technically won't happen as is_multipart_boundary()
 648                   will fail first.  But just in case..
 649                 */
 650                if (--content_top < content) {
 651                        fprintf(stderr, "Detected mismatched boundaries, "
 652                                        "can't recover\n");
 653                        exit(1);
 654                }
 655                handle_filter(&newline);
 656                strbuf_release(&newline);
 657
 658                /* skip to the next boundary */
 659                if (!find_boundary())
 660                        return 0;
 661                goto again;
 662        }
 663
 664        /* set some defaults */
 665        transfer_encoding = TE_DONTCARE;
 666        strbuf_reset(&charset);
 667        message_type = TYPE_TEXT;
 668
 669        /* slurp in this section's info */
 670        while (read_one_header_line(&line, fin))
 671                check_header(&line, p_hdr_data, 0);
 672
 673        strbuf_release(&newline);
 674        /* replenish line */
 675        if (strbuf_getline(&line, fin, '\n'))
 676                return 0;
 677        strbuf_addch(&line, '\n');
 678        return 1;
 679}
 680
 681static inline int patchbreak(const struct strbuf *line)
 682{
 683        size_t i;
 684
 685        /* Beginning of a "diff -" header? */
 686        if (!prefixcmp(line->buf, "diff -"))
 687                return 1;
 688
 689        /* CVS "Index: " line? */
 690        if (!prefixcmp(line->buf, "Index: "))
 691                return 1;
 692
 693        /*
 694         * "--- <filename>" starts patches without headers
 695         * "---<sp>*" is a manual separator
 696         */
 697        if (line->len < 4)
 698                return 0;
 699
 700        if (!prefixcmp(line->buf, "---")) {
 701                /* space followed by a filename? */
 702                if (line->buf[3] == ' ' && !isspace(line->buf[4]))
 703                        return 1;
 704                /* Just whitespace? */
 705                for (i = 3; i < line->len; i++) {
 706                        unsigned char c = line->buf[i];
 707                        if (c == '\n')
 708                                return 1;
 709                        if (!isspace(c))
 710                                break;
 711                }
 712                return 0;
 713        }
 714        return 0;
 715}
 716
 717static int is_scissors_line(const struct strbuf *line)
 718{
 719        size_t i, len = line->len;
 720        int scissors = 0, gap = 0;
 721        int first_nonblank = -1;
 722        int last_nonblank = 0, visible, perforation = 0, in_perforation = 0;
 723        const char *buf = line->buf;
 724
 725        for (i = 0; i < len; i++) {
 726                if (isspace(buf[i])) {
 727                        if (in_perforation) {
 728                                perforation++;
 729                                gap++;
 730                        }
 731                        continue;
 732                }
 733                last_nonblank = i;
 734                if (first_nonblank < 0)
 735                        first_nonblank = i;
 736                if (buf[i] == '-') {
 737                        in_perforation = 1;
 738                        perforation++;
 739                        continue;
 740                }
 741                if (i + 1 < len &&
 742                    (!memcmp(buf + i, ">8", 2) || !memcmp(buf + i, "8<", 2))) {
 743                        in_perforation = 1;
 744                        perforation += 2;
 745                        scissors += 2;
 746                        i++;
 747                        continue;
 748                }
 749                in_perforation = 0;
 750        }
 751
 752        /*
 753         * The mark must be at least 8 bytes long (e.g. "-- >8 --").
 754         * Even though there can be arbitrary cruft on the same line
 755         * (e.g. "cut here"), in order to avoid misidentification, the
 756         * perforation must occupy more than a third of the visible
 757         * width of the line, and dashes and scissors must occupy more
 758         * than half of the perforation.
 759         */
 760
 761        visible = last_nonblank - first_nonblank + 1;
 762        return (scissors && 8 <= visible &&
 763                visible < perforation * 3 &&
 764                gap * 2 < perforation);
 765}
 766
 767static int handle_commit_msg(struct strbuf *line)
 768{
 769        static int still_looking = 1;
 770
 771        if (!cmitmsg)
 772                return 0;
 773
 774        if (still_looking) {
 775                strbuf_ltrim(line);
 776                if (!line->len)
 777                        return 0;
 778        }
 779
 780        if (use_inbody_headers && still_looking) {
 781                still_looking = check_header(line, s_hdr_data, 0);
 782                if (still_looking)
 783                        return 0;
 784        } else
 785                /* Only trim the first (blank) line of the commit message
 786                 * when ignoring in-body headers.
 787                 */
 788                still_looking = 0;
 789
 790        /* normalize the log message to UTF-8. */
 791        if (metainfo_charset)
 792                convert_to_utf8(line, charset.buf);
 793
 794        if (use_scissors && is_scissors_line(line)) {
 795                int i;
 796                if (fseek(cmitmsg, 0L, SEEK_SET))
 797                        die_errno("Could not rewind output message file");
 798                if (ftruncate(fileno(cmitmsg), 0))
 799                        die_errno("Could not truncate output message file at scissors");
 800                still_looking = 1;
 801
 802                /*
 803                 * We may have already read "secondary headers"; purge
 804                 * them to give ourselves a clean restart.
 805                 */
 806                for (i = 0; header[i]; i++) {
 807                        if (s_hdr_data[i])
 808                                strbuf_release(s_hdr_data[i]);
 809                        s_hdr_data[i] = NULL;
 810                }
 811                return 0;
 812        }
 813
 814        if (patchbreak(line)) {
 815                fclose(cmitmsg);
 816                cmitmsg = NULL;
 817                return 1;
 818        }
 819
 820        fputs(line->buf, cmitmsg);
 821        return 0;
 822}
 823
 824static void handle_patch(const struct strbuf *line)
 825{
 826        fwrite(line->buf, 1, line->len, patchfile);
 827        patch_lines++;
 828}
 829
 830static void handle_filter(struct strbuf *line)
 831{
 832        static int filter = 0;
 833
 834        /* filter tells us which part we left off on */
 835        switch (filter) {
 836        case 0:
 837                if (!handle_commit_msg(line))
 838                        break;
 839                filter++;
 840        case 1:
 841                handle_patch(line);
 842                break;
 843        }
 844}
 845
 846static void handle_body(void)
 847{
 848        struct strbuf prev = STRBUF_INIT;
 849
 850        /* Skip up to the first boundary */
 851        if (*content_top) {
 852                if (!find_boundary())
 853                        goto handle_body_out;
 854        }
 855
 856        do {
 857                /* process any boundary lines */
 858                if (*content_top && is_multipart_boundary(&line)) {
 859                        /* flush any leftover */
 860                        if (prev.len) {
 861                                handle_filter(&prev);
 862                                strbuf_reset(&prev);
 863                        }
 864                        if (!handle_boundary())
 865                                goto handle_body_out;
 866                }
 867
 868                /* Unwrap transfer encoding */
 869                decode_transfer_encoding(&line);
 870
 871                switch (transfer_encoding) {
 872                case TE_BASE64:
 873                case TE_QP:
 874                {
 875                        struct strbuf **lines, **it, *sb;
 876
 877                        /* Prepend any previous partial lines */
 878                        strbuf_insert(&line, 0, prev.buf, prev.len);
 879                        strbuf_reset(&prev);
 880
 881                        /* binary data most likely doesn't have newlines */
 882                        if (message_type != TYPE_TEXT) {
 883                                handle_filter(&line);
 884                                break;
 885                        }
 886                        /*
 887                         * This is a decoded line that may contain
 888                         * multiple new lines.  Pass only one chunk
 889                         * at a time to handle_filter()
 890                         */
 891                        lines = strbuf_split(&line, '\n');
 892                        for (it = lines; (sb = *it); it++) {
 893                                if (*(it + 1) == NULL) /* The last line */
 894                                        if (sb->buf[sb->len - 1] != '\n') {
 895                                                /* Partial line, save it for later. */
 896                                                strbuf_addbuf(&prev, sb);
 897                                                break;
 898                                        }
 899                                handle_filter(sb);
 900                        }
 901                        /*
 902                         * The partial chunk is saved in "prev" and will be
 903                         * appended by the next iteration of read_line_with_nul().
 904                         */
 905                        strbuf_list_free(lines);
 906                        break;
 907                }
 908                default:
 909                        handle_filter(&line);
 910                }
 911
 912        } while (!strbuf_getwholeline(&line, fin, '\n'));
 913
 914handle_body_out:
 915        strbuf_release(&prev);
 916}
 917
 918static void output_header_lines(FILE *fout, const char *hdr, const struct strbuf *data)
 919{
 920        const char *sp = data->buf;
 921        while (1) {
 922                char *ep = strchr(sp, '\n');
 923                int len;
 924                if (!ep)
 925                        len = strlen(sp);
 926                else
 927                        len = ep - sp;
 928                fprintf(fout, "%s: %.*s\n", hdr, len, sp);
 929                if (!ep)
 930                        break;
 931                sp = ep + 1;
 932        }
 933}
 934
 935static void handle_info(void)
 936{
 937        struct strbuf *hdr;
 938        int i;
 939
 940        for (i = 0; header[i]; i++) {
 941                /* only print inbody headers if we output a patch file */
 942                if (patch_lines && s_hdr_data[i])
 943                        hdr = s_hdr_data[i];
 944                else if (p_hdr_data[i])
 945                        hdr = p_hdr_data[i];
 946                else
 947                        continue;
 948
 949                if (!memcmp(header[i], "Subject", 7)) {
 950                        if (!keep_subject) {
 951                                cleanup_subject(hdr);
 952                                cleanup_space(hdr);
 953                        }
 954                        output_header_lines(fout, "Subject", hdr);
 955                } else if (!memcmp(header[i], "From", 4)) {
 956                        cleanup_space(hdr);
 957                        handle_from(hdr);
 958                        fprintf(fout, "Author: %s\n", name.buf);
 959                        fprintf(fout, "Email: %s\n", email.buf);
 960                } else {
 961                        cleanup_space(hdr);
 962                        fprintf(fout, "%s: %s\n", header[i], hdr->buf);
 963                }
 964        }
 965        fprintf(fout, "\n");
 966}
 967
 968static int mailinfo(FILE *in, FILE *out, const char *msg, const char *patch)
 969{
 970        int peek;
 971        fin = in;
 972        fout = out;
 973
 974        cmitmsg = fopen(msg, "w");
 975        if (!cmitmsg) {
 976                perror(msg);
 977                return -1;
 978        }
 979        patchfile = fopen(patch, "w");
 980        if (!patchfile) {
 981                perror(patch);
 982                fclose(cmitmsg);
 983                return -1;
 984        }
 985
 986        p_hdr_data = xcalloc(MAX_HDR_PARSED, sizeof(*p_hdr_data));
 987        s_hdr_data = xcalloc(MAX_HDR_PARSED, sizeof(*s_hdr_data));
 988
 989        do {
 990                peek = fgetc(in);
 991        } while (isspace(peek));
 992        ungetc(peek, in);
 993
 994        /* process the email header */
 995        while (read_one_header_line(&line, fin))
 996                check_header(&line, p_hdr_data, 1);
 997
 998        handle_body();
 999        handle_info();
1000
1001        return 0;
1002}
1003
1004static int git_mailinfo_config(const char *var, const char *value, void *unused)
1005{
1006        if (prefixcmp(var, "mailinfo."))
1007                return git_default_config(var, value, unused);
1008        if (!strcmp(var, "mailinfo.scissors")) {
1009                use_scissors = git_config_bool(var, value);
1010                return 0;
1011        }
1012        /* perhaps others here */
1013        return 0;
1014}
1015
1016static const char mailinfo_usage[] =
1017        "git mailinfo [-k] [-u | --encoding=<encoding> | -n] [--scissors | --no-scissors] msg patch < mail >info";
1018
1019int cmd_mailinfo(int argc, const char **argv, const char *prefix)
1020{
1021        const char *def_charset;
1022
1023        /* NEEDSWORK: might want to do the optional .git/ directory
1024         * discovery
1025         */
1026        git_config(git_mailinfo_config, NULL);
1027
1028        def_charset = (git_commit_encoding ? git_commit_encoding : "UTF-8");
1029        metainfo_charset = def_charset;
1030
1031        while (1 < argc && argv[1][0] == '-') {
1032                if (!strcmp(argv[1], "-k"))
1033                        keep_subject = 1;
1034                else if (!strcmp(argv[1], "-u"))
1035                        metainfo_charset = def_charset;
1036                else if (!strcmp(argv[1], "-n"))
1037                        metainfo_charset = NULL;
1038                else if (!prefixcmp(argv[1], "--encoding="))
1039                        metainfo_charset = argv[1] + 11;
1040                else if (!strcmp(argv[1], "--scissors"))
1041                        use_scissors = 1;
1042                else if (!strcmp(argv[1], "--no-scissors"))
1043                        use_scissors = 0;
1044                else if (!strcmp(argv[1], "--no-inbody-headers"))
1045                        use_inbody_headers = 0;
1046                else
1047                        usage(mailinfo_usage);
1048                argc--; argv++;
1049        }
1050
1051        if (argc != 3)
1052                usage(mailinfo_usage);
1053
1054        return !!mailinfo(stdin, stdout, argv[1], argv[2]);
1055}