builtin-mailinfo.con commit combine-diff.c: type sanity (2386c29)
   1/*
   2 * Another stupid program, this one parsing the headers of an
   3 * email to figure out authorship and subject
   4 */
   5#define _GNU_SOURCE
   6#include <stdio.h>
   7#include <stdlib.h>
   8#include <string.h>
   9#include <ctype.h>
  10#ifndef NO_ICONV
  11#include <iconv.h>
  12#endif
  13#include "git-compat-util.h"
  14#include "cache.h"
  15#include "builtin.h"
  16
  17static FILE *cmitmsg, *patchfile, *fin, *fout;
  18
  19static int keep_subject = 0;
  20static const char *metainfo_charset = NULL;
  21static char line[1000];
  22static char date[1000];
  23static char name[1000];
  24static char email[1000];
  25static char subject[1000];
  26
  27static enum  {
  28        TE_DONTCARE, TE_QP, TE_BASE64,
  29} transfer_encoding;
  30static char charset[256];
  31
  32static char multipart_boundary[1000];
  33static int multipart_boundary_len;
  34static int patch_lines = 0;
  35
  36static char *sanity_check(char *name, char *email)
  37{
  38        int len = strlen(name);
  39        if (len < 3 || len > 60)
  40                return email;
  41        if (strchr(name, '@') || strchr(name, '<') || strchr(name, '>'))
  42                return email;
  43        return name;
  44}
  45
  46static int bogus_from(char *line)
  47{
  48        /* John Doe <johndoe> */
  49        char *bra, *ket, *dst, *cp;
  50
  51        /* This is fallback, so do not bother if we already have an
  52         * e-mail address.
  53         */
  54        if (*email)
  55                return 0;
  56
  57        bra = strchr(line, '<');
  58        if (!bra)
  59                return 0;
  60        ket = strchr(bra, '>');
  61        if (!ket)
  62                return 0;
  63
  64        for (dst = email, cp = bra+1; cp < ket; )
  65                *dst++ = *cp++;
  66        *dst = 0;
  67        for (cp = line; isspace(*cp); cp++)
  68                ;
  69        for (bra--; isspace(*bra); bra--)
  70                *bra = 0;
  71        cp = sanity_check(cp, email);
  72        strcpy(name, cp);
  73        return 1;
  74}
  75
  76static int handle_from(char *in_line)
  77{
  78        char line[1000];
  79        char *at;
  80        char *dst;
  81
  82        strcpy(line, in_line);
  83        at = strchr(line, '@');
  84        if (!at)
  85                return bogus_from(line);
  86
  87        /*
  88         * If we already have one email, don't take any confusing lines
  89         */
  90        if (*email && strchr(at+1, '@'))
  91                return 0;
  92
  93        /* Pick up the string around '@', possibly delimited with <>
  94         * pair; that is the email part.  White them out while copying.
  95         */
  96        while (at > line) {
  97                char c = at[-1];
  98                if (isspace(c))
  99                        break;
 100                if (c == '<') {
 101                        at[-1] = ' ';
 102                        break;
 103                }
 104                at--;
 105        }
 106        dst = email;
 107        for (;;) {
 108                unsigned char c = *at;
 109                if (!c || c == '>' || isspace(c)) {
 110                        if (c == '>')
 111                                *at = ' ';
 112                        break;
 113                }
 114                *at++ = ' ';
 115                *dst++ = c;
 116        }
 117        *dst++ = 0;
 118
 119        /* The remainder is name.  It could be "John Doe <john.doe@xz>"
 120         * or "john.doe@xz (John Doe)", but we have whited out the
 121         * email part, so trim from both ends, possibly removing
 122         * the () pair at the end.
 123         */
 124        at = line + strlen(line);
 125        while (at > line) {
 126                unsigned char c = *--at;
 127                if (!isspace(c)) {
 128                        at[(c == ')') ? 0 : 1] = 0;
 129                        break;
 130                }
 131        }
 132
 133        at = line;
 134        for (;;) {
 135                unsigned char c = *at;
 136                if (!c || !isspace(c)) {
 137                        if (c == '(')
 138                                at++;
 139                        break;
 140                }
 141                at++;
 142        }
 143        at = sanity_check(at, email);
 144        strcpy(name, at);
 145        return 1;
 146}
 147
 148static int handle_date(char *line)
 149{
 150        strcpy(date, line);
 151        return 0;
 152}
 153
 154static int handle_subject(char *line)
 155{
 156        strcpy(subject, line);
 157        return 0;
 158}
 159
 160/* NOTE NOTE NOTE.  We do not claim we do full MIME.  We just attempt
 161 * to have enough heuristics to grok MIME encoded patches often found
 162 * on our mailing lists.  For example, we do not even treat header lines
 163 * case insensitively.
 164 */
 165
 166static int slurp_attr(const char *line, const char *name, char *attr)
 167{
 168        char *ends, *ap = strcasestr(line, name);
 169        size_t sz;
 170
 171        if (!ap) {
 172                *attr = 0;
 173                return 0;
 174        }
 175        ap += strlen(name);
 176        if (*ap == '"') {
 177                ap++;
 178                ends = "\"";
 179        }
 180        else
 181                ends = "; \t";
 182        sz = strcspn(ap, ends);
 183        memcpy(attr, ap, sz);
 184        attr[sz] = 0;
 185        return 1;
 186}
 187
 188static int handle_subcontent_type(char *line)
 189{
 190        /* We do not want to mess with boundary.  Note that we do not
 191         * handle nested multipart.
 192         */
 193        if (strcasestr(line, "boundary=")) {
 194                fprintf(stderr, "Not handling nested multipart message.\n");
 195                exit(1);
 196        }
 197        slurp_attr(line, "charset=", charset);
 198        if (*charset) {
 199                int i, c;
 200                for (i = 0; (c = charset[i]) != 0; i++)
 201                        charset[i] = tolower(c);
 202        }
 203        return 0;
 204}
 205
 206static int handle_content_type(char *line)
 207{
 208        *multipart_boundary = 0;
 209        if (slurp_attr(line, "boundary=", multipart_boundary + 2)) {
 210                memcpy(multipart_boundary, "--", 2);
 211                multipart_boundary_len = strlen(multipart_boundary);
 212        }
 213        slurp_attr(line, "charset=", charset);
 214        return 0;
 215}
 216
 217static int handle_content_transfer_encoding(char *line)
 218{
 219        if (strcasestr(line, "base64"))
 220                transfer_encoding = TE_BASE64;
 221        else if (strcasestr(line, "quoted-printable"))
 222                transfer_encoding = TE_QP;
 223        else
 224                transfer_encoding = TE_DONTCARE;
 225        return 0;
 226}
 227
 228static int is_multipart_boundary(const char *line)
 229{
 230        return (!memcmp(line, multipart_boundary, multipart_boundary_len));
 231}
 232
 233static int eatspace(char *line)
 234{
 235        int len = strlen(line);
 236        while (len > 0 && isspace(line[len-1]))
 237                line[--len] = 0;
 238        return len;
 239}
 240
 241#define SEEN_FROM 01
 242#define SEEN_DATE 02
 243#define SEEN_SUBJECT 04
 244#define SEEN_BOGUS_UNIX_FROM 010
 245#define SEEN_PREFIX  020
 246
 247/* First lines of body can have From:, Date:, and Subject: or empty */
 248static void handle_inbody_header(int *seen, char *line)
 249{
 250        if (*seen & SEEN_PREFIX)
 251                return;
 252        if (isspace(*line)) {
 253                char *cp;
 254                for (cp = line + 1; *cp; cp++) {
 255                        if (!isspace(*cp))
 256                                break;
 257                }
 258                if (!*cp)
 259                        return;
 260        }
 261        if (!memcmp(">From", line, 5) && isspace(line[5])) {
 262                if (!(*seen & SEEN_BOGUS_UNIX_FROM)) {
 263                        *seen |= SEEN_BOGUS_UNIX_FROM;
 264                        return;
 265                }
 266        }
 267        if (!memcmp("From:", line, 5) && isspace(line[5])) {
 268                if (!(*seen & SEEN_FROM) && handle_from(line+6)) {
 269                        *seen |= SEEN_FROM;
 270                        return;
 271                }
 272        }
 273        if (!memcmp("Date:", line, 5) && isspace(line[5])) {
 274                if (!(*seen & SEEN_DATE)) {
 275                        handle_date(line+6);
 276                        *seen |= SEEN_DATE;
 277                        return;
 278                }
 279        }
 280        if (!memcmp("Subject:", line, 8) && isspace(line[8])) {
 281                if (!(*seen & SEEN_SUBJECT)) {
 282                        handle_subject(line+9);
 283                        *seen |= SEEN_SUBJECT;
 284                        return;
 285                }
 286        }
 287        if (!memcmp("[PATCH]", line, 7) && isspace(line[7])) {
 288                if (!(*seen & SEEN_SUBJECT)) {
 289                        handle_subject(line);
 290                        *seen |= SEEN_SUBJECT;
 291                        return;
 292                }
 293        }
 294        *seen |= SEEN_PREFIX;
 295}
 296
 297static char *cleanup_subject(char *subject)
 298{
 299        if (keep_subject)
 300                return subject;
 301        for (;;) {
 302                char *p;
 303                int len, remove;
 304                switch (*subject) {
 305                case 'r': case 'R':
 306                        if (!memcmp("e:", subject+1, 2)) {
 307                                subject +=3;
 308                                continue;
 309                        }
 310                        break;
 311                case ' ': case '\t': case ':':
 312                        subject++;
 313                        continue;
 314
 315                case '[':
 316                        p = strchr(subject, ']');
 317                        if (!p) {
 318                                subject++;
 319                                continue;
 320                        }
 321                        len = strlen(p);
 322                        remove = p - subject;
 323                        if (remove <= len *2) {
 324                                subject = p+1;
 325                                continue;
 326                        }
 327                        break;
 328                }
 329                eatspace(subject);
 330                return subject;
 331        }
 332}
 333
 334static void cleanup_space(char *buf)
 335{
 336        unsigned char c;
 337        while ((c = *buf) != 0) {
 338                buf++;
 339                if (isspace(c)) {
 340                        buf[-1] = ' ';
 341                        c = *buf;
 342                        while (isspace(c)) {
 343                                int len = strlen(buf);
 344                                memmove(buf, buf+1, len);
 345                                c = *buf;
 346                        }
 347                }
 348        }
 349}
 350
 351static void decode_header_bq(char *it);
 352typedef int (*header_fn_t)(char *);
 353struct header_def {
 354        const char *name;
 355        header_fn_t func;
 356        int namelen;
 357};
 358
 359static void check_header(char *line, struct header_def *header)
 360{
 361        int i;
 362
 363        if (header[0].namelen <= 0) {
 364                for (i = 0; header[i].name; i++)
 365                        header[i].namelen = strlen(header[i].name);
 366        }
 367        for (i = 0; header[i].name; i++) {
 368                int len = header[i].namelen;
 369                if (!strncasecmp(line, header[i].name, len) &&
 370                    line[len] == ':' && isspace(line[len + 1])) {
 371                        /* Unwrap inline B and Q encoding, and optionally
 372                         * normalize the meta information to utf8.
 373                         */
 374                        decode_header_bq(line + len + 2);
 375                        header[i].func(line + len + 2);
 376                        break;
 377                }
 378        }
 379}
 380
 381static void check_subheader_line(char *line)
 382{
 383        static struct header_def header[] = {
 384                { "Content-Type", handle_subcontent_type },
 385                { "Content-Transfer-Encoding",
 386                  handle_content_transfer_encoding },
 387                { NULL },
 388        };
 389        check_header(line, header);
 390}
 391static void check_header_line(char *line)
 392{
 393        static struct header_def header[] = {
 394                { "From", handle_from },
 395                { "Date", handle_date },
 396                { "Subject", handle_subject },
 397                { "Content-Type", handle_content_type },
 398                { "Content-Transfer-Encoding",
 399                  handle_content_transfer_encoding },
 400                { NULL },
 401        };
 402        check_header(line, header);
 403}
 404
 405static int is_rfc2822_header(char *line)
 406{
 407        /*
 408         * The section that defines the loosest possible
 409         * field name is "3.6.8 Optional fields".
 410         *
 411         * optional-field = field-name ":" unstructured CRLF
 412         * field-name = 1*ftext
 413         * ftext = %d33-57 / %59-126
 414         */
 415        int ch;
 416        char *cp = line;
 417        while ((ch = *cp++)) {
 418                if (ch == ':')
 419                        return cp != line;
 420                if ((33 <= ch && ch <= 57) ||
 421                    (59 <= ch && ch <= 126))
 422                        continue;
 423                break;
 424        }
 425        return 0;
 426}
 427
 428static int read_one_header_line(char *line, int sz, FILE *in)
 429{
 430        int ofs = 0;
 431        while (ofs < sz) {
 432                int peek, len;
 433                if (fgets(line + ofs, sz - ofs, in) == NULL)
 434                        break;
 435                len = eatspace(line + ofs);
 436                if ((len == 0) || !is_rfc2822_header(line)) {
 437                        /* Re-add the newline */
 438                        line[ofs + len] = '\n';
 439                        line[ofs + len + 1] = '\0';
 440                        break;
 441                }
 442                ofs += len;
 443                /* Yuck, 2822 header "folding" */
 444                peek = fgetc(in); ungetc(peek, in);
 445                if (peek != ' ' && peek != '\t')
 446                        break;
 447        }
 448        /* Count mbox From headers as headers */
 449        if (!ofs && !memcmp(line, "From ", 5))
 450                ofs = 1;
 451        return ofs;
 452}
 453
 454static unsigned hexval(int c)
 455{
 456        if (c >= '0' && c <= '9')
 457                return c - '0';
 458        if (c >= 'a' && c <= 'f')
 459                return c - 'a' + 10;
 460        if (c >= 'A' && c <= 'F')
 461                return c - 'A' + 10;
 462        return ~0;
 463}
 464
 465static int decode_q_segment(char *in, char *ot, char *ep, int rfc2047)
 466{
 467        int c;
 468        while ((c = *in++) != 0 && (in <= ep)) {
 469                if (c == '=') {
 470                        int d = *in++;
 471                        if (d == '\n' || !d)
 472                                break; /* drop trailing newline */
 473                        *ot++ = ((hexval(d) << 4) | hexval(*in++));
 474                        continue;
 475                }
 476                if (rfc2047 && c == '_') /* rfc2047 4.2 (2) */
 477                        c = 0x20;
 478                *ot++ = c;
 479        }
 480        *ot = 0;
 481        return 0;
 482}
 483
 484static int decode_b_segment(char *in, char *ot, char *ep)
 485{
 486        /* Decode in..ep, possibly in-place to ot */
 487        int c, pos = 0, acc = 0;
 488
 489        while ((c = *in++) != 0 && (in <= ep)) {
 490                if (c == '+')
 491                        c = 62;
 492                else if (c == '/')
 493                        c = 63;
 494                else if ('A' <= c && c <= 'Z')
 495                        c -= 'A';
 496                else if ('a' <= c && c <= 'z')
 497                        c -= 'a' - 26;
 498                else if ('0' <= c && c <= '9')
 499                        c -= '0' - 52;
 500                else if (c == '=') {
 501                        /* padding is almost like (c == 0), except we do
 502                         * not output NUL resulting only from it;
 503                         * for now we just trust the data.
 504                         */
 505                        c = 0;
 506                }
 507                else
 508                        continue; /* garbage */
 509                switch (pos++) {
 510                case 0:
 511                        acc = (c << 2);
 512                        break;
 513                case 1:
 514                        *ot++ = (acc | (c >> 4));
 515                        acc = (c & 15) << 4;
 516                        break;
 517                case 2:
 518                        *ot++ = (acc | (c >> 2));
 519                        acc = (c & 3) << 6;
 520                        break;
 521                case 3:
 522                        *ot++ = (acc | c);
 523                        acc = pos = 0;
 524                        break;
 525                }
 526        }
 527        *ot = 0;
 528        return 0;
 529}
 530
 531static void convert_to_utf8(char *line, char *charset)
 532{
 533#ifndef NO_ICONV
 534        char *in, *out;
 535        size_t insize, outsize, nrc;
 536        char outbuf[4096]; /* cheat */
 537        static char latin_one[] = "latin1";
 538        char *input_charset = *charset ? charset : latin_one;
 539        iconv_t conv = iconv_open(metainfo_charset, input_charset);
 540
 541        if (conv == (iconv_t) -1) {
 542                static int warned_latin1_once = 0;
 543                if (input_charset != latin_one) {
 544                        fprintf(stderr, "cannot convert from %s to %s\n",
 545                                input_charset, metainfo_charset);
 546                        *charset = 0;
 547                }
 548                else if (!warned_latin1_once) {
 549                        warned_latin1_once = 1;
 550                        fprintf(stderr, "tried to convert from %s to %s, "
 551                                "but your iconv does not work with it.\n",
 552                                input_charset, metainfo_charset);
 553                }
 554                return;
 555        }
 556        in = line;
 557        insize = strlen(in);
 558        out = outbuf;
 559        outsize = sizeof(outbuf);
 560        nrc = iconv(conv, &in, &insize, &out, &outsize);
 561        iconv_close(conv);
 562        if (nrc == (size_t) -1)
 563                return;
 564        *out = 0;
 565        strcpy(line, outbuf);
 566#endif
 567}
 568
 569static void decode_header_bq(char *it)
 570{
 571        char *in, *out, *ep, *cp, *sp;
 572        char outbuf[1000];
 573
 574        in = it;
 575        out = outbuf;
 576        while ((ep = strstr(in, "=?")) != NULL) {
 577                int sz, encoding;
 578                char charset_q[256], piecebuf[256];
 579                if (in != ep) {
 580                        sz = ep - in;
 581                        memcpy(out, in, sz);
 582                        out += sz;
 583                        in += sz;
 584                }
 585                /* E.g.
 586                 * ep : "=?iso-2022-jp?B?GyR...?= foo"
 587                 * ep : "=?ISO-8859-1?Q?Foo=FCbar?= baz"
 588                 */
 589                ep += 2;
 590                cp = strchr(ep, '?');
 591                if (!cp)
 592                        return; /* no munging */
 593                for (sp = ep; sp < cp; sp++)
 594                        charset_q[sp - ep] = tolower(*sp);
 595                charset_q[cp - ep] = 0;
 596                encoding = cp[1];
 597                if (!encoding || cp[2] != '?')
 598                        return; /* no munging */
 599                ep = strstr(cp + 3, "?=");
 600                if (!ep)
 601                        return; /* no munging */
 602                switch (tolower(encoding)) {
 603                default:
 604                        return; /* no munging */
 605                case 'b':
 606                        sz = decode_b_segment(cp + 3, piecebuf, ep);
 607                        break;
 608                case 'q':
 609                        sz = decode_q_segment(cp + 3, piecebuf, ep, 1);
 610                        break;
 611                }
 612                if (sz < 0)
 613                        return;
 614                if (metainfo_charset)
 615                        convert_to_utf8(piecebuf, charset_q);
 616                strcpy(out, piecebuf);
 617                out += strlen(out);
 618                in = ep + 2;
 619        }
 620        strcpy(out, in);
 621        strcpy(it, outbuf);
 622}
 623
 624static void decode_transfer_encoding(char *line)
 625{
 626        char *ep;
 627
 628        switch (transfer_encoding) {
 629        case TE_QP:
 630                ep = line + strlen(line);
 631                decode_q_segment(line, line, ep, 0);
 632                break;
 633        case TE_BASE64:
 634                ep = line + strlen(line);
 635                decode_b_segment(line, line, ep);
 636                break;
 637        case TE_DONTCARE:
 638                break;
 639        }
 640}
 641
 642static void handle_info(void)
 643{
 644        char *sub;
 645
 646        sub = cleanup_subject(subject);
 647        cleanup_space(name);
 648        cleanup_space(date);
 649        cleanup_space(email);
 650        cleanup_space(sub);
 651
 652        fprintf(fout, "Author: %s\nEmail: %s\nSubject: %s\nDate: %s\n\n",
 653               name, email, sub, date);
 654}
 655
 656/* We are inside message body and have read line[] already.
 657 * Spit out the commit log.
 658 */
 659static int handle_commit_msg(int *seen)
 660{
 661        if (!cmitmsg)
 662                return 0;
 663        do {
 664                if (!memcmp("diff -", line, 6) ||
 665                    !memcmp("---", line, 3) ||
 666                    !memcmp("Index: ", line, 7))
 667                        break;
 668                if ((multipart_boundary[0] && is_multipart_boundary(line))) {
 669                        /* We come here when the first part had only
 670                         * the commit message without any patch.  We
 671                         * pretend we have not seen this line yet, and
 672                         * go back to the loop.
 673                         */
 674                        return 1;
 675                }
 676
 677                /* Unwrap transfer encoding and optionally
 678                 * normalize the log message to UTF-8.
 679                 */
 680                decode_transfer_encoding(line);
 681                if (metainfo_charset)
 682                        convert_to_utf8(line, charset);
 683
 684                handle_inbody_header(seen, line);
 685                if (!(*seen & SEEN_PREFIX))
 686                        continue;
 687
 688                fputs(line, cmitmsg);
 689        } while (fgets(line, sizeof(line), fin) != NULL);
 690        fclose(cmitmsg);
 691        cmitmsg = NULL;
 692        return 0;
 693}
 694
 695/* We have done the commit message and have the first
 696 * line of the patch in line[].
 697 */
 698static void handle_patch(void)
 699{
 700        do {
 701                if (multipart_boundary[0] && is_multipart_boundary(line))
 702                        break;
 703                /* Only unwrap transfer encoding but otherwise do not
 704                 * do anything.  We do *NOT* want UTF-8 conversion
 705                 * here; we are dealing with the user payload.
 706                 */
 707                decode_transfer_encoding(line);
 708                fputs(line, patchfile);
 709                patch_lines++;
 710        } while (fgets(line, sizeof(line), fin) != NULL);
 711}
 712
 713/* multipart boundary and transfer encoding are set up for us, and we
 714 * are at the end of the sub header.  do equivalent of handle_body up
 715 * to the next boundary without closing patchfile --- we will expect
 716 * that the first part to contain commit message and a patch, and
 717 * handle other parts as pure patches.
 718 */
 719static int handle_multipart_one_part(int *seen)
 720{
 721        int n = 0;
 722
 723        while (fgets(line, sizeof(line), fin) != NULL) {
 724        again:
 725                n++;
 726                if (is_multipart_boundary(line))
 727                        break;
 728                if (handle_commit_msg(seen))
 729                        goto again;
 730                handle_patch();
 731                break;
 732        }
 733        if (n == 0)
 734                return -1;
 735        return 0;
 736}
 737
 738static void handle_multipart_body(void)
 739{
 740        int seen = 0;
 741        int part_num = 0;
 742
 743        /* Skip up to the first boundary */
 744        while (fgets(line, sizeof(line), fin) != NULL)
 745                if (is_multipart_boundary(line)) {
 746                        part_num = 1;
 747                        break;
 748                }
 749        if (!part_num)
 750                return;
 751        /* We are on boundary line.  Start slurping the subhead. */
 752        while (1) {
 753                int hdr = read_one_header_line(line, sizeof(line), fin);
 754                if (!hdr) {
 755                        if (handle_multipart_one_part(&seen) < 0)
 756                                return;
 757                        /* Reset per part headers */
 758                        transfer_encoding = TE_DONTCARE;
 759                        charset[0] = 0;
 760                }
 761                else
 762                        check_subheader_line(line);
 763        }
 764        fclose(patchfile);
 765        if (!patch_lines) {
 766                fprintf(stderr, "No patch found\n");
 767                exit(1);
 768        }
 769}
 770
 771/* Non multipart message */
 772static void handle_body(void)
 773{
 774        int seen = 0;
 775
 776        handle_commit_msg(&seen);
 777        handle_patch();
 778        fclose(patchfile);
 779        if (!patch_lines) {
 780                fprintf(stderr, "No patch found\n");
 781                exit(1);
 782        }
 783}
 784
 785int mailinfo(FILE *in, FILE *out, int ks, const char *encoding,
 786             const char *msg, const char *patch)
 787{
 788        keep_subject = ks;
 789        metainfo_charset = encoding;
 790        fin = in;
 791        fout = out;
 792
 793        cmitmsg = fopen(msg, "w");
 794        if (!cmitmsg) {
 795                perror(msg);
 796                return -1;
 797        }
 798        patchfile = fopen(patch, "w");
 799        if (!patchfile) {
 800                perror(patch);
 801                fclose(cmitmsg);
 802                return -1;
 803        }
 804        while (1) {
 805                int hdr = read_one_header_line(line, sizeof(line), fin);
 806                if (!hdr) {
 807                        if (multipart_boundary[0])
 808                                handle_multipart_body();
 809                        else
 810                                handle_body();
 811                        handle_info();
 812                        break;
 813                }
 814                check_header_line(line);
 815        }
 816
 817        return 0;
 818}
 819
 820static const char mailinfo_usage[] =
 821        "git-mailinfo [-k] [-u | --encoding=<encoding>] msg patch <mail >info";
 822
 823int cmd_mailinfo(int argc, const char **argv, char **envp)
 824{
 825        /* NEEDSWORK: might want to do the optional .git/ directory
 826         * discovery
 827         */
 828        git_config(git_default_config);
 829
 830        while (1 < argc && argv[1][0] == '-') {
 831                if (!strcmp(argv[1], "-k"))
 832                        keep_subject = 1;
 833                else if (!strcmp(argv[1], "-u"))
 834                        metainfo_charset = git_commit_encoding;
 835                else if (!strncmp(argv[1], "--encoding=", 11))
 836                        metainfo_charset = argv[1] + 11;
 837                else
 838                        usage(mailinfo_usage);
 839                argc--; argv++;
 840        }
 841
 842        if (argc != 3)
 843                usage(mailinfo_usage);
 844
 845        return !!mailinfo(stdin, stdout, keep_subject, metainfo_charset, argv[1], argv[2]);
 846}