convert.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "object-store.h"
   4 #include "attr.h"
   5 #include "run-command.h"
   6 #include "quote.h"
   7 #include "sigchain.h"
   8 #include "pkt-line.h"
   9 #include "sub-process.h"
  10 #include "utf8.h"
  11 #include "ll-merge.h"
  12
  13 /*
  14  * convert.c - convert a file when checking it out and checking it in.
  15  *
  16  * This should use the pathname to decide on whether it wants to do some
  17  * more interesting conversions (automatic gzip/unzip, general format
  18  * conversions etc etc), but by default it just does automatic CRLF<->LF
  19  * translation when the "text" attribute or "auto_crlf" option is set.
  20  */
  21
  22 /* Stat bits: When BIN is set, the txt bits are unset */
  23 #define CONVERT_STAT_BITS_TXT_LF    0x1
  24 #define CONVERT_STAT_BITS_TXT_CRLF  0x2
  25 #define CONVERT_STAT_BITS_BIN       0x4
  26
  27 enum crlf_action {
  28         CRLF_UNDEFINED,
  29         CRLF_BINARY,
  30         CRLF_TEXT,
  31         CRLF_TEXT_INPUT,
  32         CRLF_TEXT_CRLF,
  33         CRLF_AUTO,
  34         CRLF_AUTO_INPUT,
  35         CRLF_AUTO_CRLF
  36 };
  37
  38 struct text_stat {
  39         /* NUL, CR, LF and CRLF counts */
  40         unsigned nul, lonecr, lonelf, crlf;
  41
  42         /* These are just approximations! */
  43         unsigned printable, nonprintable;
  44 };
  45
  46 static void gather_stats(const char *buf, unsigned long size, struct text_stat *stats)
  47 {
  48         unsigned long i;
  49
  50         memset(stats, 0, sizeof(*stats));
  51
  52         for (i = 0; i < size; i++) {
  53                 unsigned char c = buf[i];
  54                 if (c == '\r') {
  55                         if (i+1 < size && buf[i+1] == '\n') {
  56                                 stats->crlf++;
  57                                 i++;
  58                         } else
  59                                 stats->lonecr++;
  60                         continue;
  61                 }
  62                 if (c == '\n') {
  63                         stats->lonelf++;
  64                         continue;
  65                 }
  66                 if (c == 127)
  67                         /* DEL */
  68                         stats->nonprintable++;
  69                 else if (c < 32) {
  70                         switch (c) {
  71                                 /* BS, HT, ESC and FF */
  72                         case '\b': case '\t': case '\033': case '\014':
  73                                 stats->printable++;
  74                                 break;
  75                         case 0:
  76                                 stats->nul++;
  77                                 /* fall through */
  78                         default:
  79                                 stats->nonprintable++;
  80                         }
  81                 }
  82                 else
  83                         stats->printable++;
  84         }
  85
  86         /* If file ends with EOF then don't count this EOF as non-printable. */
  87         if (size >= 1 && buf[size-1] == '\032')
  88                 stats->nonprintable--;
  89 }
  90
  91 /*
  92  * The same heuristics as diff.c::mmfile_is_binary()
  93  * We treat files with bare CR as binary
  94  */
  95 static int convert_is_binary(const struct text_stat *stats)
  96 {
  97         if (stats->lonecr)
  98                 return 1;
  99         if (stats->nul)
 100                 return 1;
 101         if ((stats->printable >> 7) < stats->nonprintable)
 102                 return 1;
 103         return 0;
 104 }
 105
 106 static unsigned int gather_convert_stats(const char *data, unsigned long size)
 107 {
 108         struct text_stat stats;
 109         int ret = 0;
 110         if (!data || !size)
 111                 return 0;
 112         gather_stats(data, size, &stats);
 113         if (convert_is_binary(&stats))
 114                 ret |= CONVERT_STAT_BITS_BIN;
 115         if (stats.crlf)
 116                 ret |= CONVERT_STAT_BITS_TXT_CRLF;
 117         if (stats.lonelf)
 118                 ret |=  CONVERT_STAT_BITS_TXT_LF;
 119
 120         return ret;
 121 }
 122
 123 static const char *gather_convert_stats_ascii(const char *data, unsigned long size)
 124 {
 125         unsigned int convert_stats = gather_convert_stats(data, size);
 126
 127         if (convert_stats & CONVERT_STAT_BITS_BIN)
 128                 return "-text";
 129         switch (convert_stats) {
 130         case CONVERT_STAT_BITS_TXT_LF:
 131                 return "lf";
 132         case CONVERT_STAT_BITS_TXT_CRLF:
 133                 return "crlf";
 134         case CONVERT_STAT_BITS_TXT_LF | CONVERT_STAT_BITS_TXT_CRLF:
 135                 return "mixed";
 136         default:
 137                 return "none";
 138         }
 139 }
 140
 141 const char *get_cached_convert_stats_ascii(const struct index_state *istate,
 142                                            const char *path)
 143 {
 144         const char *ret;
 145         unsigned long sz;
 146         void *data = read_blob_data_from_index(istate, path, &sz);
 147         ret = gather_convert_stats_ascii(data, sz);
 148         free(data);
 149         return ret;
 150 }
 151
 152 const char *get_wt_convert_stats_ascii(const char *path)
 153 {
 154         const char *ret = "";
 155         struct strbuf sb = STRBUF_INIT;
 156         if (strbuf_read_file(&sb, path, 0) >= 0)
 157                 ret = gather_convert_stats_ascii(sb.buf, sb.len);
 158         strbuf_release(&sb);
 159         return ret;
 160 }
 161
 162 static int text_eol_is_crlf(void)
 163 {
 164         if (auto_crlf == AUTO_CRLF_TRUE)
 165                 return 1;
 166         else if (auto_crlf == AUTO_CRLF_INPUT)
 167                 return 0;
 168         if (core_eol == EOL_CRLF)
 169                 return 1;
 170         if (core_eol == EOL_UNSET && EOL_NATIVE == EOL_CRLF)
 171                 return 1;
 172         return 0;
 173 }
 174
 175 static enum eol output_eol(enum crlf_action crlf_action)
 176 {
 177         switch (crlf_action) {
 178         case CRLF_BINARY:
 179                 return EOL_UNSET;
 180         case CRLF_TEXT_CRLF:
 181                 return EOL_CRLF;
 182         case CRLF_TEXT_INPUT:
 183                 return EOL_LF;
 184         case CRLF_UNDEFINED:
 185         case CRLF_AUTO_CRLF:
 186                 return EOL_CRLF;
 187         case CRLF_AUTO_INPUT:
 188                 return EOL_LF;
 189         case CRLF_TEXT:
 190         case CRLF_AUTO:
 191                 /* fall through */
 192                 return text_eol_is_crlf() ? EOL_CRLF : EOL_LF;
 193         }
 194         warning(_("illegal crlf_action %d"), (int)crlf_action);
 195         return core_eol;
 196 }
 197
 198 static void check_global_conv_flags_eol(const char *path,
 199                             struct text_stat *old_stats, struct text_stat *new_stats,
 200                             int conv_flags)
 201 {
 202         if (old_stats->crlf && !new_stats->crlf ) {
 203                 /*
 204                  * CRLFs would not be restored by checkout
 205                  */
 206                 if (conv_flags & CONV_EOL_RNDTRP_DIE)
 207                         die(_("CRLF would be replaced by LF in %s"), path);
 208                 else if (conv_flags & CONV_EOL_RNDTRP_WARN)
 209                         warning(_("CRLF will be replaced by LF in %s.\n"
 210                                   "The file will have its original line"
 211                                   " endings in your working directory"), path);
 212         } else if (old_stats->lonelf && !new_stats->lonelf ) {
 213                 /*
 214                  * CRLFs would be added by checkout
 215                  */
 216                 if (conv_flags & CONV_EOL_RNDTRP_DIE)
 217                         die(_("LF would be replaced by CRLF in %s"), path);
 218                 else if (conv_flags & CONV_EOL_RNDTRP_WARN)
 219                         warning(_("LF will be replaced by CRLF in %s.\n"
 220                                   "The file will have its original line"
 221                                   " endings in your working directory"), path);
 222         }
 223 }
 224
 225 static int has_crlf_in_index(const struct index_state *istate, const char *path)
 226 {
 227         unsigned long sz;
 228         void *data;
 229         const char *crp;
 230         int has_crlf = 0;
 231
 232         data = read_blob_data_from_index(istate, path, &sz);
 233         if (!data)
 234                 return 0;
 235
 236         crp = memchr(data, '\r', sz);
 237         if (crp) {
 238                 unsigned int ret_stats;
 239                 ret_stats = gather_convert_stats(data, sz);
 240                 if (!(ret_stats & CONVERT_STAT_BITS_BIN) &&
 241                     (ret_stats & CONVERT_STAT_BITS_TXT_CRLF))
 242                         has_crlf = 1;
 243         }
 244         free(data);
 245         return has_crlf;
 246 }
 247
 248 static int will_convert_lf_to_crlf(struct text_stat *stats,
 249                                    enum crlf_action crlf_action)
 250 {
 251         if (output_eol(crlf_action) != EOL_CRLF)
 252                 return 0;
 253         /* No "naked" LF? Nothing to convert, regardless. */
 254         if (!stats->lonelf)
 255                 return 0;
 256
 257         if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) {
 258                 /* If we have any CR or CRLF line endings, we do not touch it */
 259                 /* This is the new safer autocrlf-handling */
 260                 if (stats->lonecr || stats->crlf)
 261                         return 0;
 262
 263                 if (convert_is_binary(stats))
 264                         return 0;
 265         }
 266         return 1;
 267
 268 }
 269
 270 static int validate_encoding(const char *path, const char *enc,
 271                       const char *data, size_t len, int die_on_error)
 272 {
 273         const char *stripped;
 274
 275         /* We only check for UTF here as UTF?? can be an alias for UTF-?? */
 276         if (skip_iprefix(enc, "UTF", &stripped)) {
 277                 skip_prefix(stripped, "-", &stripped);
 278
 279                 /*
 280                  * Check for detectable errors in UTF encodings
 281                  */
 282                 if (has_prohibited_utf_bom(enc, data, len)) {
 283                         const char *error_msg = _(
 284                                 "BOM is prohibited in '%s' if encoded as %s");
 285                         /*
 286                          * This advice is shown for UTF-??BE and UTF-??LE encodings.
 287                          * We cut off the last two characters of the encoding name
 288                          * to generate the encoding name suitable for BOMs.
 289                          */
 290                         const char *advise_msg = _(
 291                                 "The file '%s' contains a byte order "
 292                                 "mark (BOM). Please use UTF-%.*s as "
 293                                 "working-tree-encoding.");
 294                         int stripped_len = strlen(stripped) - strlen("BE");
 295                         advise(advise_msg, path, stripped_len, stripped);
 296                         if (die_on_error)
 297                                 die(error_msg, path, enc);
 298                         else {
 299                                 return error(error_msg, path, enc);
 300                         }
 301
 302                 } else if (is_missing_required_utf_bom(enc, data, len)) {
 303                         const char *error_msg = _(
 304                                 "BOM is required in '%s' if encoded as %s");
 305                         const char *advise_msg = _(
 306                                 "The file '%s' is missing a byte order "
 307                                 "mark (BOM). Please use UTF-%sBE or UTF-%sLE "
 308                                 "(depending on the byte order) as "
 309                                 "working-tree-encoding.");
 310                         advise(advise_msg, path, stripped, stripped);
 311                         if (die_on_error)
 312                                 die(error_msg, path, enc);
 313                         else {
 314                                 return error(error_msg, path, enc);
 315                         }
 316                 }
 317
 318         }
 319         return 0;
 320 }
 321
 322 static void trace_encoding(const char *context, const char *path,
 323                            const char *encoding, const char *buf, size_t len)
 324 {
 325         static struct trace_key coe = TRACE_KEY_INIT(WORKING_TREE_ENCODING);
 326         struct strbuf trace = STRBUF_INIT;
 327         int i;
 328
 329         strbuf_addf(&trace, "%s (%s, considered %s):\n", context, path, encoding);
 330         for (i = 0; i < len && buf; ++i) {
 331                 strbuf_addf(
 332                         &trace, "| \033[2m%2i:\033[0m %2x \033[2m%c\033[0m%c",
 333                         i,
 334                         (unsigned char) buf[i],
 335                         (buf[i] > 32 && buf[i] < 127 ? buf[i] : ' '),
 336                         ((i+1) % 8 && (i+1) < len ? ' ' : '\n')
 337                 );
 338         }
 339         strbuf_addchars(&trace, '\n', 1);
 340
 341         trace_strbuf(&coe, &trace);
 342         strbuf_release(&trace);
 343 }
 344
 345 static int check_roundtrip(const char *enc_name)
 346 {
 347         /*
 348          * check_roundtrip_encoding contains a string of comma and/or
 349          * space separated encodings (eg. "UTF-16, ASCII, CP1125").
 350          * Search for the given encoding in that string.
 351          */
 352         const char *found = strcasestr(check_roundtrip_encoding, enc_name);
 353         const char *next;
 354         int len;
 355         if (!found)
 356                 return 0;
 357         next = found + strlen(enc_name);
 358         len = strlen(check_roundtrip_encoding);
 359         return (found && (
 360                         /*
 361                          * check that the found encoding is at the
 362                          * beginning of check_roundtrip_encoding or
 363                          * that it is prefixed with a space or comma
 364                          */
 365                         found == check_roundtrip_encoding || (
 366                                 (isspace(found[-1]) || found[-1] == ',')
 367                         )
 368                 ) && (
 369                         /*
 370                          * check that the found encoding is at the
 371                          * end of check_roundtrip_encoding or
 372                          * that it is suffixed with a space or comma
 373                          */
 374                         next == check_roundtrip_encoding + len || (
 375                                 next < check_roundtrip_encoding + len &&
 376                                 (isspace(next[0]) || next[0] == ',')
 377                         )
 378                 ));
 379 }
 380
 381 static const char *default_encoding = "UTF-8";
 382
 383 static int encode_to_git(const char *path, const char *src, size_t src_len,
 384                          struct strbuf *buf, const char *enc, int conv_flags)
 385 {
 386         char *dst;
 387         size_t dst_len;
 388         int die_on_error = conv_flags & CONV_WRITE_OBJECT;
 389
 390         /*
 391          * No encoding is specified or there is nothing to encode.
 392          * Tell the caller that the content was not modified.
 393          */
 394         if (!enc || (src && !src_len))
 395                 return 0;
 396
 397         /*
 398          * Looks like we got called from "would_convert_to_git()".
 399          * This means Git wants to know if it would encode (= modify!)
 400          * the content. Let's answer with "yes", since an encoding was
 401          * specified.
 402          */
 403         if (!buf && !src)
 404                 return 1;
 405
 406         if (validate_encoding(path, enc, src, src_len, die_on_error))
 407                 return 0;
 408
 409         trace_encoding("source", path, enc, src, src_len);
 410         dst = reencode_string_len(src, src_len, default_encoding, enc,
 411                                   &dst_len);
 412         if (!dst) {
 413                 /*
 414                  * We could add the blob "as-is" to Git. However, on checkout
 415                  * we would try to re-encode to the original encoding. This
 416                  * would fail and we would leave the user with a messed-up
 417                  * working tree. Let's try to avoid this by screaming loud.
 418                  */
 419                 const char* msg = _("failed to encode '%s' from %s to %s");
 420                 if (die_on_error)
 421                         die(msg, path, enc, default_encoding);
 422                 else {
 423                         error(msg, path, enc, default_encoding);
 424                         return 0;
 425                 }
 426         }
 427         trace_encoding("destination", path, default_encoding, dst, dst_len);
 428
 429         /*
 430          * UTF supports lossless conversion round tripping [1] and conversions
 431          * between UTF and other encodings are mostly round trip safe as
 432          * Unicode aims to be a superset of all other character encodings.
 433          * However, certain encodings (e.g. SHIFT-JIS) are known to have round
 434          * trip issues [2]. Check the round trip conversion for all encodings
 435          * listed in core.checkRoundtripEncoding.
 436          *
 437          * The round trip check is only performed if content is written to Git.
 438          * This ensures that no information is lost during conversion to/from
 439          * the internal UTF-8 representation.
 440          *
 441          * Please note, the code below is not tested because I was not able to
 442          * generate a faulty round trip without an iconv error. Iconv errors
 443          * are already caught above.
 444          *
 445          * [1] http://unicode.org/faq/utf_bom.html#gen2
 446          * [2] https://support.microsoft.com/en-us/help/170559/prb-conversion-problem-between-shift-jis-and-unicode
 447          */
 448         if (die_on_error && check_roundtrip(enc)) {
 449                 char *re_src;
 450                 size_t re_src_len;
 451
 452                 re_src = reencode_string_len(dst, dst_len,
 453                                              enc, default_encoding,
 454                                              &re_src_len);
 455
 456                 trace_printf("Checking roundtrip encoding for %s...\n", enc);
 457                 trace_encoding("reencoded source", path, enc,
 458                                re_src, re_src_len);
 459
 460                 if (!re_src || src_len != re_src_len ||
 461                     memcmp(src, re_src, src_len)) {
 462                         const char* msg = _("encoding '%s' from %s to %s and "
 463                                             "back is not the same");
 464                         die(msg, path, enc, default_encoding);
 465                 }
 466
 467                 free(re_src);
 468         }
 469
 470         strbuf_attach(buf, dst, dst_len, dst_len + 1);
 471         return 1;
 472 }
 473
 474 static int encode_to_worktree(const char *path, const char *src, size_t src_len,
 475                               struct strbuf *buf, const char *enc)
 476 {
 477         char *dst;
 478         size_t dst_len;
 479
 480         /*
 481          * No encoding is specified or there is nothing to encode.
 482          * Tell the caller that the content was not modified.
 483          */
 484         if (!enc || (src && !src_len))
 485                 return 0;
 486
 487         dst = reencode_string_len(src, src_len, enc, default_encoding,
 488                                   &dst_len);
 489         if (!dst) {
 490                 error(_("failed to encode '%s' from %s to %s"),
 491                       path, default_encoding, enc);
 492                 return 0;
 493         }
 494
 495         strbuf_attach(buf, dst, dst_len, dst_len + 1);
 496         return 1;
 497 }
 498
 499 static int crlf_to_git(const struct index_state *istate,
 500                        const char *path, const char *src, size_t len,
 501                        struct strbuf *buf,
 502                        enum crlf_action crlf_action, int conv_flags)
 503 {
 504         struct text_stat stats;
 505         char *dst;
 506         int convert_crlf_into_lf;
 507
 508         if (crlf_action == CRLF_BINARY ||
 509             (src && !len))
 510                 return 0;
 511
 512         /*
 513          * If we are doing a dry-run and have no source buffer, there is
 514          * nothing to analyze; we must assume we would convert.
 515          */
 516         if (!buf && !src)
 517                 return 1;
 518
 519         gather_stats(src, len, &stats);
 520         /* Optimization: No CRLF? Nothing to convert, regardless. */
 521         convert_crlf_into_lf = !!stats.crlf;
 522
 523         if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) {
 524                 if (convert_is_binary(&stats))
 525                         return 0;
 526                 /*
 527                  * If the file in the index has any CR in it, do not
 528                  * convert.  This is the new safer autocrlf handling,
 529                  * unless we want to renormalize in a merge or
 530                  * cherry-pick.
 531                  */
 532                 if ((!(conv_flags & CONV_EOL_RENORMALIZE)) &&
 533                     has_crlf_in_index(istate, path))
 534                         convert_crlf_into_lf = 0;
 535         }
 536         if (((conv_flags & CONV_EOL_RNDTRP_WARN) ||
 537              ((conv_flags & CONV_EOL_RNDTRP_DIE) && len))) {
 538                 struct text_stat new_stats;
 539                 memcpy(&new_stats, &stats, sizeof(new_stats));
 540                 /* simulate "git add" */
 541                 if (convert_crlf_into_lf) {
 542                         new_stats.lonelf += new_stats.crlf;
 543                         new_stats.crlf = 0;
 544                 }
 545                 /* simulate "git checkout" */
 546                 if (will_convert_lf_to_crlf(&new_stats, crlf_action)) {
 547                         new_stats.crlf += new_stats.lonelf;
 548                         new_stats.lonelf = 0;
 549                 }
 550                 check_global_conv_flags_eol(path, &stats, &new_stats, conv_flags);
 551         }
 552         if (!convert_crlf_into_lf)
 553                 return 0;
 554
 555         /*
 556          * At this point all of our source analysis is done, and we are sure we
 557          * would convert. If we are in dry-run mode, we can give an answer.
 558          */
 559         if (!buf)
 560                 return 1;
 561
 562         /* only grow if not in place */
 563         if (strbuf_avail(buf) + buf->len < len)
 564                 strbuf_grow(buf, len - buf->len);
 565         dst = buf->buf;
 566         if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) {
 567                 /*
 568                  * If we guessed, we already know we rejected a file with
 569                  * lone CR, and we can strip a CR without looking at what
 570                  * follow it.
 571                  */
 572                 do {
 573                         unsigned char c = *src++;
 574                         if (c != '\r')
 575                                 *dst++ = c;
 576                 } while (--len);
 577         } else {
 578                 do {
 579                         unsigned char c = *src++;
 580                         if (! (c == '\r' && (1 < len && *src == '\n')))
 581                                 *dst++ = c;
 582                 } while (--len);
 583         }
 584         strbuf_setlen(buf, dst - buf->buf);
 585         return 1;
 586 }
 587
 588 static int crlf_to_worktree(const char *src, size_t len,
 589                             struct strbuf *buf, enum crlf_action crlf_action)
 590 {
 591         char *to_free = NULL;
 592         struct text_stat stats;
 593
 594         if (!len || output_eol(crlf_action) != EOL_CRLF)
 595                 return 0;
 596
 597         gather_stats(src, len, &stats);
 598         if (!will_convert_lf_to_crlf(&stats, crlf_action))
 599                 return 0;
 600
 601         /* are we "faking" in place editing ? */
 602         if (src == buf->buf)
 603                 to_free = strbuf_detach(buf, NULL);
 604
 605         strbuf_grow(buf, len + stats.lonelf);
 606         for (;;) {
 607                 const char *nl = memchr(src, '\n', len);
 608                 if (!nl)
 609                         break;
 610                 if (nl > src && nl[-1] == '\r') {
 611                         strbuf_add(buf, src, nl + 1 - src);
 612                 } else {
 613                         strbuf_add(buf, src, nl - src);
 614                         strbuf_addstr(buf, "\r\n");
 615                 }
 616                 len -= nl + 1 - src;
 617                 src  = nl + 1;
 618         }
 619         strbuf_add(buf, src, len);
 620
 621         free(to_free);
 622         return 1;
 623 }
 624
 625 struct filter_params {
 626         const char *src;
 627         unsigned long size;
 628         int fd;
 629         const char *cmd;
 630         const char *path;
 631 };
 632
 633 static int filter_buffer_or_fd(int in, int out, void *data)
 634 {
 635         /*
 636          * Spawn cmd and feed the buffer contents through its stdin.
 637          */
 638         struct child_process child_process = CHILD_PROCESS_INIT;
 639         struct filter_params *params = (struct filter_params *)data;
 640         int write_err, status;
 641
 642         /* apply % substitution to cmd */
 643         struct strbuf cmd = STRBUF_INIT;
 644         struct strbuf path = STRBUF_INIT;
 645         struct strbuf_expand_dict_entry dict[] = {
 646                 { "f", NULL, },
 647                 { NULL, NULL, },
 648         };
 649
 650         /* quote the path to preserve spaces, etc. */
 651         sq_quote_buf(&path, params->path);
 652         dict[0].value = path.buf;
 653
 654         /* expand all %f with the quoted path */
 655         strbuf_expand(&cmd, params->cmd, strbuf_expand_dict_cb, &dict);
 656         strbuf_release(&path);
 657
 658         strvec_push(&child_process.args, cmd.buf);
 659         child_process.use_shell = 1;
 660         child_process.in = -1;
 661         child_process.out = out;
 662
 663         if (start_command(&child_process)) {
 664                 strbuf_release(&cmd);
 665                 return error(_("cannot fork to run external filter '%s'"),
 666                              params->cmd);
 667         }
 668
 669         sigchain_push(SIGPIPE, SIG_IGN);
 670
 671         if (params->src) {
 672                 write_err = (write_in_full(child_process.in,
 673                                            params->src, params->size) < 0);
 674                 if (errno == EPIPE)
 675                         write_err = 0;
 676         } else {
 677                 write_err = copy_fd(params->fd, child_process.in);
 678                 if (write_err == COPY_WRITE_ERROR && errno == EPIPE)
 679                         write_err = 0;
 680         }
 681
 682         if (close(child_process.in))
 683                 write_err = 1;
 684         if (write_err)
 685                 error(_("cannot feed the input to external filter '%s'"),
 686                       params->cmd);
 687
 688         sigchain_pop(SIGPIPE);
 689
 690         status = finish_command(&child_process);
 691         if (status)
 692                 error(_("external filter '%s' failed %d"), params->cmd, status);
 693
 694         strbuf_release(&cmd);
 695         return (write_err || status);
 696 }
 697
 698 static int apply_single_file_filter(const char *path, const char *src, size_t len, int fd,
 699                                     struct strbuf *dst, const char *cmd)
 700 {
 701         /*
 702          * Create a pipeline to have the command filter the buffer's
 703          * contents.
 704          *
 705          * (child --> cmd) --> us
 706          */
 707         int err = 0;
 708         struct strbuf nbuf = STRBUF_INIT;
 709         struct async async;
 710         struct filter_params params;
 711
 712         memset(&async, 0, sizeof(async));
 713         async.proc = filter_buffer_or_fd;
 714         async.data = &params;
 715         async.out = -1;
 716         params.src = src;
 717         params.size = len;
 718         params.fd = fd;
 719         params.cmd = cmd;
 720         params.path = path;
 721
 722         fflush(NULL);
 723         if (start_async(&async))
 724                 return 0;       /* error was already reported */
 725
 726         if (strbuf_read(&nbuf, async.out, 0) < 0) {
 727                 err = error(_("read from external filter '%s' failed"), cmd);
 728         }
 729         if (close(async.out)) {
 730                 err = error(_("read from external filter '%s' failed"), cmd);
 731         }
 732         if (finish_async(&async)) {
 733                 err = error(_("external filter '%s' failed"), cmd);
 734         }
 735
 736         if (!err) {
 737                 strbuf_swap(dst, &nbuf);
 738         }
 739         strbuf_release(&nbuf);
 740         return !err;
 741 }
 742
 743 #define CAP_CLEAN    (1u<<0)
 744 #define CAP_SMUDGE   (1u<<1)
 745 #define CAP_DELAY    (1u<<2)
 746
 747 struct cmd2process {
 748         struct subprocess_entry subprocess; /* must be the first member! */
 749         unsigned int supported_capabilities;
 750 };
 751
 752 static int subprocess_map_initialized;
 753 static struct hashmap subprocess_map;
 754
 755 static int start_multi_file_filter_fn(struct subprocess_entry *subprocess)
 756 {
 757         static int versions[] = {2, 0};
 758         static struct subprocess_capability capabilities[] = {
 759                 { "clean",  CAP_CLEAN  },
 760                 { "smudge", CAP_SMUDGE },
 761                 { "delay",  CAP_DELAY  },
 762                 { NULL, 0 }
 763         };
 764         struct cmd2process *entry = (struct cmd2process *)subprocess;
 765         return subprocess_handshake(subprocess, "git-filter", versions, NULL,
 766                                     capabilities,
 767                                     &entry->supported_capabilities);
 768 }
 769
 770 static void handle_filter_error(const struct strbuf *filter_status,
 771                                 struct cmd2process *entry,
 772                                 const unsigned int wanted_capability)
 773 {
 774         if (!strcmp(filter_status->buf, "error"))
 775                 ; /* The filter signaled a problem with the file. */
 776         else if (!strcmp(filter_status->buf, "abort") && wanted_capability) {
 777                 /*
 778                  * The filter signaled a permanent problem. Don't try to filter
 779                  * files with the same command for the lifetime of the current
 780                  * Git process.
 781                  */
 782                  entry->supported_capabilities &= ~wanted_capability;
 783         } else {
 784                 /*
 785                  * Something went wrong with the protocol filter.
 786                  * Force shutdown and restart if another blob requires filtering.
 787                  */
 788                 error(_("external filter '%s' failed"), entry->subprocess.cmd);
 789                 subprocess_stop(&subprocess_map, &entry->subprocess);
 790                 free(entry);
 791         }
 792 }
 793
 794 static int apply_multi_file_filter(const char *path, const char *src, size_t len,
 795                                    int fd, struct strbuf *dst, const char *cmd,
 796                                    const unsigned int wanted_capability,
 797                                    const struct checkout_metadata *meta,
 798                                    struct delayed_checkout *dco)
 799 {
 800         int err;
 801         int can_delay = 0;
 802         struct cmd2process *entry;
 803         struct child_process *process;
 804         struct strbuf nbuf = STRBUF_INIT;
 805         struct strbuf filter_status = STRBUF_INIT;
 806         const char *filter_type;
 807
 808         if (!subprocess_map_initialized) {
 809                 subprocess_map_initialized = 1;
 810                 hashmap_init(&subprocess_map, cmd2process_cmp, NULL, 0);
 811                 entry = NULL;
 812         } else {
 813                 entry = (struct cmd2process *)subprocess_find_entry(&subprocess_map, cmd);
 814         }
 815
 816         fflush(NULL);
 817
 818         if (!entry) {
 819                 entry = xmalloc(sizeof(*entry));
 820                 entry->supported_capabilities = 0;
 821
 822                 if (subprocess_start(&subprocess_map, &entry->subprocess, cmd, start_multi_file_filter_fn)) {
 823                         free(entry);
 824                         return 0;
 825                 }
 826         }
 827         process = &entry->subprocess.process;
 828
 829         if (!(entry->supported_capabilities & wanted_capability))
 830                 return 0;
 831
 832         if (wanted_capability & CAP_CLEAN)
 833                 filter_type = "clean";
 834         else if (wanted_capability & CAP_SMUDGE)
 835                 filter_type = "smudge";
 836         else
 837                 die(_("unexpected filter type"));
 838
 839         sigchain_push(SIGPIPE, SIG_IGN);
 840
 841         assert(strlen(filter_type) < LARGE_PACKET_DATA_MAX - strlen("command=\n"));
 842         err = packet_write_fmt_gently(process->in, "command=%s\n", filter_type);
 843         if (err)
 844                 goto done;
 845
 846         err = strlen(path) > LARGE_PACKET_DATA_MAX - strlen("pathname=\n");
 847         if (err) {
 848                 error(_("path name too long for external filter"));
 849                 goto done;
 850         }
 851
 852         err = packet_write_fmt_gently(process->in, "pathname=%s\n", path);
 853         if (err)
 854                 goto done;
 855
 856         if (meta && meta->refname) {
 857                 err = packet_write_fmt_gently(process->in, "ref=%s\n", meta->refname);
 858                 if (err)
 859                         goto done;
 860         }
 861
 862         if (meta && !is_null_oid(&meta->treeish)) {
 863                 err = packet_write_fmt_gently(process->in, "treeish=%s\n", oid_to_hex(&meta->treeish));
 864                 if (err)
 865                         goto done;
 866         }
 867
 868         if (meta && !is_null_oid(&meta->blob)) {
 869                 err = packet_write_fmt_gently(process->in, "blob=%s\n", oid_to_hex(&meta->blob));
 870                 if (err)
 871                         goto done;
 872         }
 873
 874         if ((entry->supported_capabilities & CAP_DELAY) &&
 875             dco && dco->state == CE_CAN_DELAY) {
 876                 can_delay = 1;
 877                 err = packet_write_fmt_gently(process->in, "can-delay=1\n");
 878                 if (err)
 879                         goto done;
 880         }
 881
 882         err = packet_flush_gently(process->in);
 883         if (err)
 884                 goto done;
 885
 886         if (fd >= 0)
 887                 err = write_packetized_from_fd(fd, process->in);
 888         else
 889                 err = write_packetized_from_buf(src, len, process->in);
 890         if (err)
 891                 goto done;
 892
 893         err = subprocess_read_status(process->out, &filter_status);
 894         if (err)
 895                 goto done;
 896
 897         if (can_delay && !strcmp(filter_status.buf, "delayed")) {
 898                 string_list_insert(&dco->filters, cmd);
 899                 string_list_insert(&dco->paths, path);
 900         } else {
 901                 /* The filter got the blob and wants to send us a response. */
 902                 err = strcmp(filter_status.buf, "success");
 903                 if (err)
 904                         goto done;
 905
 906                 err = read_packetized_to_strbuf(process->out, &nbuf) < 0;
 907                 if (err)
 908                         goto done;
 909
 910                 err = subprocess_read_status(process->out, &filter_status);
 911                 if (err)
 912                         goto done;
 913
 914                 err = strcmp(filter_status.buf, "success");
 915         }
 916
 917 done:
 918         sigchain_pop(SIGPIPE);
 919
 920         if (err)
 921                 handle_filter_error(&filter_status, entry, wanted_capability);
 922         else
 923                 strbuf_swap(dst, &nbuf);
 924         strbuf_release(&nbuf);
 925         return !err;
 926 }
 927
 928
 929 int async_query_available_blobs(const char *cmd, struct string_list *available_paths)
 930 {
 931         int err;
 932         char *line;
 933         struct cmd2process *entry;
 934         struct child_process *process;
 935         struct strbuf filter_status = STRBUF_INIT;
 936
 937         assert(subprocess_map_initialized);
 938         entry = (struct cmd2process *)subprocess_find_entry(&subprocess_map, cmd);
 939         if (!entry) {
 940                 error(_("external filter '%s' is not available anymore although "
 941                         "not all paths have been filtered"), cmd);
 942                 return 0;
 943         }
 944         process = &entry->subprocess.process;
 945         sigchain_push(SIGPIPE, SIG_IGN);
 946
 947         err = packet_write_fmt_gently(
 948                 process->in, "command=list_available_blobs\n");
 949         if (err)
 950                 goto done;
 951
 952         err = packet_flush_gently(process->in);
 953         if (err)
 954                 goto done;
 955
 956         while ((line = packet_read_line(process->out, NULL))) {
 957                 const char *path;
 958                 if (skip_prefix(line, "pathname=", &path))
 959                         string_list_insert(available_paths, xstrdup(path));
 960                 else
 961                         ; /* ignore unknown keys */
 962         }
 963
 964         err = subprocess_read_status(process->out, &filter_status);
 965         if (err)
 966                 goto done;
 967
 968         err = strcmp(filter_status.buf, "success");
 969
 970 done:
 971         sigchain_pop(SIGPIPE);
 972
 973         if (err)
 974                 handle_filter_error(&filter_status, entry, 0);
 975         return !err;
 976 }
 977
 978 static struct convert_driver {
 979         const char *name;
 980         struct convert_driver *next;
 981         const char *smudge;
 982         const char *clean;
 983         const char *process;
 984         int required;
 985 } *user_convert, **user_convert_tail;
 986
 987 static int apply_filter(const char *path, const char *src, size_t len,
 988                         int fd, struct strbuf *dst, struct convert_driver *drv,
 989                         const unsigned int wanted_capability,
 990                         const struct checkout_metadata *meta,
 991                         struct delayed_checkout *dco)
 992 {
 993         const char *cmd = NULL;
 994
 995         if (!drv)
 996                 return 0;
 997
 998         if (!dst)
 999                 return 1;
1000
1001         if ((wanted_capability & CAP_CLEAN) && !drv->process && drv->clean)
1002                 cmd = drv->clean;
1003         else if ((wanted_capability & CAP_SMUDGE) && !drv->process && drv->smudge)
1004                 cmd = drv->smudge;
1005
1006         if (cmd && *cmd)
1007                 return apply_single_file_filter(path, src, len, fd, dst, cmd);
1008         else if (drv->process && *drv->process)
1009                 return apply_multi_file_filter(path, src, len, fd, dst,
1010                         drv->process, wanted_capability, meta, dco);
1011
1012         return 0;
1013 }
1014
1015 static int read_convert_config(const char *var, const char *value, void *cb)
1016 {
1017         const char *key, *name;
1018         size_t namelen;
1019         struct convert_driver *drv;
1020
1021         /*
1022          * External conversion drivers are configured using
1023          * "filter.<name>.variable".
1024          */
1025         if (parse_config_key(var, "filter", &name, &namelen, &key) < 0 || !name)
1026                 return 0;
1027         for (drv = user_convert; drv; drv = drv->next)
1028                 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
1029                         break;
1030         if (!drv) {
1031                 drv = xcalloc(1, sizeof(struct convert_driver));
1032                 drv->name = xmemdupz(name, namelen);
1033                 *user_convert_tail = drv;
1034                 user_convert_tail = &(drv->next);
1035         }
1036
1037         /*
1038          * filter.<name>.smudge and filter.<name>.clean specifies
1039          * the command line:
1040          *
1041          *      command-line
1042          *
1043          * The command-line will not be interpolated in any way.
1044          */
1045
1046         if (!strcmp("smudge", key))
1047                 return git_config_string(&drv->smudge, var, value);
1048
1049         if (!strcmp("clean", key))
1050                 return git_config_string(&drv->clean, var, value);
1051
1052         if (!strcmp("process", key))
1053                 return git_config_string(&drv->process, var, value);
1054
1055         if (!strcmp("required", key)) {
1056                 drv->required = git_config_bool(var, value);
1057                 return 0;
1058         }
1059
1060         return 0;
1061 }
1062
1063 static int count_ident(const char *cp, unsigned long size)
1064 {
1065         /*
1066          * "$Id: 0000000000000000000000000000000000000000 $" <=> "$Id$"
1067          */
1068         int cnt = 0;
1069         char ch;
1070
1071         while (size) {
1072                 ch = *cp++;
1073                 size--;
1074                 if (ch != '$')
1075                         continue;
1076                 if (size < 3)
1077                         break;
1078                 if (memcmp("Id", cp, 2))
1079                         continue;
1080                 ch = cp[2];
1081                 cp += 3;
1082                 size -= 3;
1083                 if (ch == '$')
1084                         cnt++; /* $Id$ */
1085                 if (ch != ':')
1086                         continue;
1087
1088                 /*
1089                  * "$Id: ... "; scan up to the closing dollar sign and discard.
1090                  */
1091                 while (size) {
1092                         ch = *cp++;
1093                         size--;
1094                         if (ch == '$') {
1095                                 cnt++;
1096                                 break;
1097                         }
1098                         if (ch == '\n')
1099                                 break;
1100                 }
1101         }
1102         return cnt;
1103 }
1104
1105 static int ident_to_git(const char *src, size_t len,
1106                         struct strbuf *buf, int ident)
1107 {
1108         char *dst, *dollar;
1109
1110         if (!ident || (src && !count_ident(src, len)))
1111                 return 0;
1112
1113         if (!buf)
1114                 return 1;
1115
1116         /* only grow if not in place */
1117         if (strbuf_avail(buf) + buf->len < len)
1118                 strbuf_grow(buf, len - buf->len);
1119         dst = buf->buf;
1120         for (;;) {
1121                 dollar = memchr(src, '$', len);
1122                 if (!dollar)
1123                         break;
1124                 memmove(dst, src, dollar + 1 - src);
1125                 dst += dollar + 1 - src;
1126                 len -= dollar + 1 - src;
1127                 src  = dollar + 1;
1128
1129                 if (len > 3 && !memcmp(src, "Id:", 3)) {
1130                         dollar = memchr(src + 3, '$', len - 3);
1131                         if (!dollar)
1132                                 break;
1133                         if (memchr(src + 3, '\n', dollar - src - 3)) {
1134                                 /* Line break before the next dollar. */
1135                                 continue;
1136                         }
1137
1138                         memcpy(dst, "Id$", 3);
1139                         dst += 3;
1140                         len -= dollar + 1 - src;
1141                         src  = dollar + 1;
1142                 }
1143         }
1144         memmove(dst, src, len);
1145         strbuf_setlen(buf, dst + len - buf->buf);
1146         return 1;
1147 }
1148
1149 static int ident_to_worktree(const char *src, size_t len,
1150                              struct strbuf *buf, int ident)
1151 {
1152         struct object_id oid;
1153         char *to_free = NULL, *dollar, *spc;
1154         int cnt;
1155
1156         if (!ident)
1157                 return 0;
1158
1159         cnt = count_ident(src, len);
1160         if (!cnt)
1161                 return 0;
1162
1163         /* are we "faking" in place editing ? */
1164         if (src == buf->buf)
1165                 to_free = strbuf_detach(buf, NULL);
1166         hash_object_file(the_hash_algo, src, len, "blob", &oid);
1167
1168         strbuf_grow(buf, len + cnt * (the_hash_algo->hexsz + 3));
1169         for (;;) {
1170                 /* step 1: run to the next '$' */
1171                 dollar = memchr(src, '$', len);
1172                 if (!dollar)
1173                         break;
1174                 strbuf_add(buf, src, dollar + 1 - src);
1175                 len -= dollar + 1 - src;
1176                 src  = dollar + 1;
1177
1178                 /* step 2: does it looks like a bit like Id:xxx$ or Id$ ? */
1179                 if (len < 3 || memcmp("Id", src, 2))
1180                         continue;
1181
1182                 /* step 3: skip over Id$ or Id:xxxxx$ */
1183                 if (src[2] == '$') {
1184                         src += 3;
1185                         len -= 3;
1186                 } else if (src[2] == ':') {
1187                         /*
1188                          * It's possible that an expanded Id has crept its way into the
1189                          * repository, we cope with that by stripping the expansion out.
1190                          * This is probably not a good idea, since it will cause changes
1191                          * on checkout, which won't go away by stash, but let's keep it
1192                          * for git-style ids.
1193                          */
1194                         dollar = memchr(src + 3, '$', len - 3);
1195                         if (!dollar) {
1196                                 /* incomplete keyword, no more '$', so just quit the loop */
1197                                 break;
1198                         }
1199
1200                         if (memchr(src + 3, '\n', dollar - src - 3)) {
1201                                 /* Line break before the next dollar. */
1202                                 continue;
1203                         }
1204
1205                         spc = memchr(src + 4, ' ', dollar - src - 4);
1206                         if (spc && spc < dollar-1) {
1207                                 /* There are spaces in unexpected places.
1208                                  * This is probably an id from some other
1209                                  * versioning system. Keep it for now.
1210                                  */
1211                                 continue;
1212                         }
1213
1214                         len -= dollar + 1 - src;
1215                         src  = dollar + 1;
1216                 } else {
1217                         /* it wasn't a "Id$" or "Id:xxxx$" */
1218                         continue;
1219                 }
1220
1221                 /* step 4: substitute */
1222                 strbuf_addstr(buf, "Id: ");
1223                 strbuf_addstr(buf, oid_to_hex(&oid));
1224                 strbuf_addstr(buf, " $");
1225         }
1226         strbuf_add(buf, src, len);
1227
1228         free(to_free);
1229         return 1;
1230 }
1231
1232 static const char *git_path_check_encoding(struct attr_check_item *check)
1233 {
1234         const char *value = check->value;
1235
1236         if (ATTR_UNSET(value) || !strlen(value))
1237                 return NULL;
1238
1239         if (ATTR_TRUE(value) || ATTR_FALSE(value)) {
1240                 die(_("true/false are no valid working-tree-encodings"));
1241         }
1242
1243         /* Don't encode to the default encoding */
1244         if (same_encoding(value, default_encoding))
1245                 return NULL;
1246
1247         return value;
1248 }
1249
1250 static enum crlf_action git_path_check_crlf(struct attr_check_item *check)
1251 {
1252         const char *value = check->value;
1253
1254         if (ATTR_TRUE(value))
1255                 return CRLF_TEXT;
1256         else if (ATTR_FALSE(value))
1257                 return CRLF_BINARY;
1258         else if (ATTR_UNSET(value))
1259                 ;
1260         else if (!strcmp(value, "input"))
1261                 return CRLF_TEXT_INPUT;
1262         else if (!strcmp(value, "auto"))
1263                 return CRLF_AUTO;
1264         return CRLF_UNDEFINED;
1265 }
1266
1267 static enum eol git_path_check_eol(struct attr_check_item *check)
1268 {
1269         const char *value = check->value;
1270
1271         if (ATTR_UNSET(value))
1272                 ;
1273         else if (!strcmp(value, "lf"))
1274                 return EOL_LF;
1275         else if (!strcmp(value, "crlf"))
1276                 return EOL_CRLF;
1277         return EOL_UNSET;
1278 }
1279
1280 static struct convert_driver *git_path_check_convert(struct attr_check_item *check)
1281 {
1282         const char *value = check->value;
1283         struct convert_driver *drv;
1284
1285         if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1286                 return NULL;
1287         for (drv = user_convert; drv; drv = drv->next)
1288                 if (!strcmp(value, drv->name))
1289                         return drv;
1290         return NULL;
1291 }
1292
1293 static int git_path_check_ident(struct attr_check_item *check)
1294 {
1295         const char *value = check->value;
1296
1297         return !!ATTR_TRUE(value);
1298 }
1299
1300 struct conv_attrs {
1301         struct convert_driver *drv;
1302         enum crlf_action attr_action; /* What attr says */
1303         enum crlf_action crlf_action; /* When no attr is set, use core.autocrlf */
1304         int ident;
1305         const char *working_tree_encoding; /* Supported encoding or default encoding if NULL */
1306 };
1307
1308 static struct attr_check *check;
1309
1310 static void convert_attrs(const struct index_state *istate,
1311                           struct conv_attrs *ca, const char *path)
1312 {
1313         struct attr_check_item *ccheck = NULL;
1314
1315         if (!check) {
1316                 check = attr_check_initl("crlf", "ident", "filter",
1317                                          "eol", "text", "working-tree-encoding",
1318                                          NULL);
1319                 user_convert_tail = &user_convert;
1320                 git_config(read_convert_config, NULL);
1321         }
1322
1323         git_check_attr(istate, path, check);
1324         ccheck = check->items;
1325         ca->crlf_action = git_path_check_crlf(ccheck + 4);
1326         if (ca->crlf_action == CRLF_UNDEFINED)
1327                 ca->crlf_action = git_path_check_crlf(ccheck + 0);
1328         ca->ident = git_path_check_ident(ccheck + 1);
1329         ca->drv = git_path_check_convert(ccheck + 2);
1330         if (ca->crlf_action != CRLF_BINARY) {
1331                 enum eol eol_attr = git_path_check_eol(ccheck + 3);
1332                 if (ca->crlf_action == CRLF_AUTO && eol_attr == EOL_LF)
1333                         ca->crlf_action = CRLF_AUTO_INPUT;
1334                 else if (ca->crlf_action == CRLF_AUTO && eol_attr == EOL_CRLF)
1335                         ca->crlf_action = CRLF_AUTO_CRLF;
1336                 else if (eol_attr == EOL_LF)
1337                         ca->crlf_action = CRLF_TEXT_INPUT;
1338                 else if (eol_attr == EOL_CRLF)
1339                         ca->crlf_action = CRLF_TEXT_CRLF;
1340         }
1341         ca->working_tree_encoding = git_path_check_encoding(ccheck + 5);
1342
1343         /* Save attr and make a decision for action */
1344         ca->attr_action = ca->crlf_action;
1345         if (ca->crlf_action == CRLF_TEXT)
1346                 ca->crlf_action = text_eol_is_crlf() ? CRLF_TEXT_CRLF : CRLF_TEXT_INPUT;
1347         if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_FALSE)
1348                 ca->crlf_action = CRLF_BINARY;
1349         if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_TRUE)
1350                 ca->crlf_action = CRLF_AUTO_CRLF;
1351         if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_INPUT)
1352                 ca->crlf_action = CRLF_AUTO_INPUT;
1353 }
1354
1355 void reset_parsed_attributes(void)
1356 {
1357         struct convert_driver *drv, *next;
1358
1359         attr_check_free(check);
1360         check = NULL;
1361         reset_merge_attributes();
1362
1363         for (drv = user_convert; drv; drv = next) {
1364                 next = drv->next;
1365                 free((void *)drv->name);
1366                 free(drv);
1367         }
1368         user_convert = NULL;
1369         user_convert_tail = NULL;
1370 }
1371
1372 int would_convert_to_git_filter_fd(const struct index_state *istate, const char *path)
1373 {
1374         struct conv_attrs ca;
1375
1376         convert_attrs(istate, &ca, path);
1377         if (!ca.drv)
1378                 return 0;
1379
1380         /*
1381          * Apply a filter to an fd only if the filter is required to succeed.
1382          * We must die if the filter fails, because the original data before
1383          * filtering is not available.
1384          */
1385         if (!ca.drv->required)
1386                 return 0;
1387
1388         return apply_filter(path, NULL, 0, -1, NULL, ca.drv, CAP_CLEAN, NULL, NULL);
1389 }
1390
1391 const char *get_convert_attr_ascii(const struct index_state *istate, const char *path)
1392 {
1393         struct conv_attrs ca;
1394
1395         convert_attrs(istate, &ca, path);
1396         switch (ca.attr_action) {
1397         case CRLF_UNDEFINED:
1398                 return "";
1399         case CRLF_BINARY:
1400                 return "-text";
1401         case CRLF_TEXT:
1402                 return "text";
1403         case CRLF_TEXT_INPUT:
1404                 return "text eol=lf";
1405         case CRLF_TEXT_CRLF:
1406                 return "text eol=crlf";
1407         case CRLF_AUTO:
1408                 return "text=auto";
1409         case CRLF_AUTO_CRLF:
1410                 return "text=auto eol=crlf";
1411         case CRLF_AUTO_INPUT:
1412                 return "text=auto eol=lf";
1413         }
1414         return "";
1415 }
1416
1417 int convert_to_git(const struct index_state *istate,
1418                    const char *path, const char *src, size_t len,
1419                    struct strbuf *dst, int conv_flags)
1420 {
1421         int ret = 0;
1422         struct conv_attrs ca;
1423
1424         convert_attrs(istate, &ca, path);
1425
1426         ret |= apply_filter(path, src, len, -1, dst, ca.drv, CAP_CLEAN, NULL, NULL);
1427         if (!ret && ca.drv && ca.drv->required)
1428                 die(_("%s: clean filter '%s' failed"), path, ca.drv->name);
1429
1430         if (ret && dst) {
1431                 src = dst->buf;
1432                 len = dst->len;
1433         }
1434
1435         ret |= encode_to_git(path, src, len, dst, ca.working_tree_encoding, conv_flags);
1436         if (ret && dst) {
1437                 src = dst->buf;
1438                 len = dst->len;
1439         }
1440
1441         if (!(conv_flags & CONV_EOL_KEEP_CRLF)) {
1442                 ret |= crlf_to_git(istate, path, src, len, dst, ca.crlf_action, conv_flags);
1443                 if (ret && dst) {
1444                         src = dst->buf;
1445                         len = dst->len;
1446                 }
1447         }
1448         return ret | ident_to_git(src, len, dst, ca.ident);
1449 }
1450
1451 void convert_to_git_filter_fd(const struct index_state *istate,
1452                               const char *path, int fd, struct strbuf *dst,
1453                               int conv_flags)
1454 {
1455         struct conv_attrs ca;
1456         convert_attrs(istate, &ca, path);
1457
1458         assert(ca.drv);
1459         assert(ca.drv->clean || ca.drv->process);
1460
1461         if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN, NULL, NULL))
1462                 die(_("%s: clean filter '%s' failed"), path, ca.drv->name);
1463
1464         encode_to_git(path, dst->buf, dst->len, dst, ca.working_tree_encoding, conv_flags);
1465         crlf_to_git(istate, path, dst->buf, dst->len, dst, ca.crlf_action, conv_flags);
1466         ident_to_git(dst->buf, dst->len, dst, ca.ident);
1467 }
1468
1469 static int convert_to_working_tree_internal(const struct index_state *istate,
1470                                             const char *path, const char *src,
1471                                             size_t len, struct strbuf *dst,
1472                                             int normalizing,
1473                                             const struct checkout_metadata *meta,
1474                                             struct delayed_checkout *dco)
1475 {
1476         int ret = 0, ret_filter = 0;
1477         struct conv_attrs ca;
1478
1479         convert_attrs(istate, &ca, path);
1480
1481         ret |= ident_to_worktree(src, len, dst, ca.ident);
1482         if (ret) {
1483                 src = dst->buf;
1484                 len = dst->len;
1485         }
1486         /*
1487          * CRLF conversion can be skipped if normalizing, unless there
1488          * is a smudge or process filter (even if the process filter doesn't
1489          * support smudge).  The filters might expect CRLFs.
1490          */
1491         if ((ca.drv && (ca.drv->smudge || ca.drv->process)) || !normalizing) {
1492                 ret |= crlf_to_worktree(src, len, dst, ca.crlf_action);
1493                 if (ret) {
1494                         src = dst->buf;
1495                         len = dst->len;
1496                 }
1497         }
1498
1499         ret |= encode_to_worktree(path, src, len, dst, ca.working_tree_encoding);
1500         if (ret) {
1501                 src = dst->buf;
1502                 len = dst->len;
1503         }
1504
1505         ret_filter = apply_filter(
1506                 path, src, len, -1, dst, ca.drv, CAP_SMUDGE, meta, dco);
1507         if (!ret_filter && ca.drv && ca.drv->required)
1508                 die(_("%s: smudge filter %s failed"), path, ca.drv->name);
1509
1510         return ret | ret_filter;
1511 }
1512
1513 int async_convert_to_working_tree(const struct index_state *istate,
1514                                   const char *path, const char *src,
1515                                   size_t len, struct strbuf *dst,
1516                                   const struct checkout_metadata *meta,
1517                                   void *dco)
1518 {
1519         return convert_to_working_tree_internal(istate, path, src, len, dst, 0, meta, dco);
1520 }
1521
1522 int convert_to_working_tree(const struct index_state *istate,
1523                             const char *path, const char *src,
1524                             size_t len, struct strbuf *dst,
1525                             const struct checkout_metadata *meta)
1526 {
1527         return convert_to_working_tree_internal(istate, path, src, len, dst, 0, meta, NULL);
1528 }
1529
1530 int renormalize_buffer(const struct index_state *istate, const char *path,
1531                        const char *src, size_t len, struct strbuf *dst)
1532 {
1533         int ret = convert_to_working_tree_internal(istate, path, src, len, dst, 1, NULL, NULL);
1534         if (ret) {
1535                 src = dst->buf;
1536                 len = dst->len;
1537         }
1538         return ret | convert_to_git(istate, path, src, len, dst, CONV_EOL_RENORMALIZE);
1539 }
1540
1541 /*****************************************************************
1542  *
1543  * Streaming conversion support
1544  *
1545  *****************************************************************/
1546
1547 typedef int (*filter_fn)(struct stream_filter *,
1548                          const char *input, size_t *isize_p,
1549                          char *output, size_t *osize_p);
1550 typedef void (*free_fn)(struct stream_filter *);
1551
1552 struct stream_filter_vtbl {
1553         filter_fn filter;
1554         free_fn free;
1555 };
1556
1557 struct stream_filter {
1558         struct stream_filter_vtbl *vtbl;
1559 };
1560
1561 static int null_filter_fn(struct stream_filter *filter,
1562                           const char *input, size_t *isize_p,
1563                           char *output, size_t *osize_p)
1564 {
1565         size_t count;
1566
1567         if (!input)
1568                 return 0; /* we do not keep any states */
1569         count = *isize_p;
1570         if (*osize_p < count)
1571                 count = *osize_p;
1572         if (count) {
1573                 memmove(output, input, count);
1574                 *isize_p -= count;
1575                 *osize_p -= count;
1576         }
1577         return 0;
1578 }
1579
1580 static void null_free_fn(struct stream_filter *filter)
1581 {
1582         ; /* nothing -- null instances are shared */
1583 }
1584
1585 static struct stream_filter_vtbl null_vtbl = {
1586         null_filter_fn,
1587         null_free_fn,
1588 };
1589
1590 static struct stream_filter null_filter_singleton = {
1591         &null_vtbl,
1592 };
1593
1594 int is_null_stream_filter(struct stream_filter *filter)
1595 {
1596         return filter == &null_filter_singleton;
1597 }
1598
1599
1600 /*
1601  * LF-to-CRLF filter
1602  */
1603
1604 struct lf_to_crlf_filter {
1605         struct stream_filter filter;
1606         unsigned has_held:1;
1607         char held;
1608 };
1609
1610 static int lf_to_crlf_filter_fn(struct stream_filter *filter,
1611                                 const char *input, size_t *isize_p,
1612                                 char *output, size_t *osize_p)
1613 {
1614         size_t count, o = 0;
1615         struct lf_to_crlf_filter *lf_to_crlf = (struct lf_to_crlf_filter *)filter;
1616
1617         /*
1618          * We may be holding onto the CR to see if it is followed by a
1619          * LF, in which case we would need to go to the main loop.
1620          * Otherwise, just emit it to the output stream.
1621          */
1622         if (lf_to_crlf->has_held && (lf_to_crlf->held != '\r' || !input)) {
1623                 output[o++] = lf_to_crlf->held;
1624                 lf_to_crlf->has_held = 0;
1625         }
1626
1627         /* We are told to drain */
1628         if (!input) {
1629                 *osize_p -= o;
1630                 return 0;
1631         }
1632
1633         count = *isize_p;
1634         if (count || lf_to_crlf->has_held) {
1635                 size_t i;
1636                 int was_cr = 0;
1637
1638                 if (lf_to_crlf->has_held) {
1639                         was_cr = 1;
1640                         lf_to_crlf->has_held = 0;
1641                 }
1642
1643                 for (i = 0; o < *osize_p && i < count; i++) {
1644                         char ch = input[i];
1645
1646                         if (ch == '\n') {
1647                                 output[o++] = '\r';
1648                         } else if (was_cr) {
1649                                 /*
1650                                  * Previous round saw CR and it is not followed
1651                                  * by a LF; emit the CR before processing the
1652                                  * current character.
1653                                  */
1654                                 output[o++] = '\r';
1655                         }
1656
1657                         /*
1658                          * We may have consumed the last output slot,
1659                          * in which case we need to break out of this
1660                          * loop; hold the current character before
1661                          * returning.
1662                          */
1663                         if (*osize_p <= o) {
1664                                 lf_to_crlf->has_held = 1;
1665                                 lf_to_crlf->held = ch;
1666                                 continue; /* break but increment i */
1667                         }
1668
1669                         if (ch == '\r') {
1670                                 was_cr = 1;
1671                                 continue;
1672                         }
1673
1674                         was_cr = 0;
1675                         output[o++] = ch;
1676                 }
1677
1678                 *osize_p -= o;
1679                 *isize_p -= i;
1680
1681                 if (!lf_to_crlf->has_held && was_cr) {
1682                         lf_to_crlf->has_held = 1;
1683                         lf_to_crlf->held = '\r';
1684                 }
1685         }
1686         return 0;
1687 }
1688
1689 static void lf_to_crlf_free_fn(struct stream_filter *filter)
1690 {
1691         free(filter);
1692 }
1693
1694 static struct stream_filter_vtbl lf_to_crlf_vtbl = {
1695         lf_to_crlf_filter_fn,
1696         lf_to_crlf_free_fn,
1697 };
1698
1699 static struct stream_filter *lf_to_crlf_filter(void)
1700 {
1701         struct lf_to_crlf_filter *lf_to_crlf = xcalloc(1, sizeof(*lf_to_crlf));
1702
1703         lf_to_crlf->filter.vtbl = &lf_to_crlf_vtbl;
1704         return (struct stream_filter *)lf_to_crlf;
1705 }
1706
1707 /*
1708  * Cascade filter
1709  */
1710 #define FILTER_BUFFER 1024
1711 struct cascade_filter {
1712         struct stream_filter filter;
1713         struct stream_filter *one;
1714         struct stream_filter *two;
1715         char buf[FILTER_BUFFER];
1716         int end, ptr;
1717 };
1718
1719 static int cascade_filter_fn(struct stream_filter *filter,
1720                              const char *input, size_t *isize_p,
1721                              char *output, size_t *osize_p)
1722 {
1723         struct cascade_filter *cas = (struct cascade_filter *) filter;
1724         size_t filled = 0;
1725         size_t sz = *osize_p;
1726         size_t to_feed, remaining;
1727
1728         /*
1729          * input -- (one) --> buf -- (two) --> output
1730          */
1731         while (filled < sz) {
1732                 remaining = sz - filled;
1733
1734                 /* do we already have something to feed two with? */
1735                 if (cas->ptr < cas->end) {
1736                         to_feed = cas->end - cas->ptr;
1737                         if (stream_filter(cas->two,
1738                                           cas->buf + cas->ptr, &to_feed,
1739                                           output + filled, &remaining))
1740                                 return -1;
1741                         cas->ptr += (cas->end - cas->ptr) - to_feed;
1742                         filled = sz - remaining;
1743                         continue;
1744                 }
1745
1746                 /* feed one from upstream and have it emit into our buffer */
1747                 to_feed = input ? *isize_p : 0;
1748                 if (input && !to_feed)
1749                         break;
1750                 remaining = sizeof(cas->buf);
1751                 if (stream_filter(cas->one,
1752                                   input, &to_feed,
1753                                   cas->buf, &remaining))
1754                         return -1;
1755                 cas->end = sizeof(cas->buf) - remaining;
1756                 cas->ptr = 0;
1757                 if (input) {
1758                         size_t fed = *isize_p - to_feed;
1759                         *isize_p -= fed;
1760                         input += fed;
1761                 }
1762
1763                 /* do we know that we drained one completely? */
1764                 if (input || cas->end)
1765                         continue;
1766
1767                 /* tell two to drain; we have nothing more to give it */
1768                 to_feed = 0;
1769                 remaining = sz - filled;
1770                 if (stream_filter(cas->two,
1771                                   NULL, &to_feed,
1772                                   output + filled, &remaining))
1773                         return -1;
1774                 if (remaining == (sz - filled))
1775                         break; /* completely drained two */
1776                 filled = sz - remaining;
1777         }
1778         *osize_p -= filled;
1779         return 0;
1780 }
1781
1782 static void cascade_free_fn(struct stream_filter *filter)
1783 {
1784         struct cascade_filter *cas = (struct cascade_filter *)filter;
1785         free_stream_filter(cas->one);
1786         free_stream_filter(cas->two);
1787         free(filter);
1788 }
1789
1790 static struct stream_filter_vtbl cascade_vtbl = {
1791         cascade_filter_fn,
1792         cascade_free_fn,
1793 };
1794
1795 static struct stream_filter *cascade_filter(struct stream_filter *one,
1796                                             struct stream_filter *two)
1797 {
1798         struct cascade_filter *cascade;
1799
1800         if (!one || is_null_stream_filter(one))
1801                 return two;
1802         if (!two || is_null_stream_filter(two))
1803                 return one;
1804
1805         cascade = xmalloc(sizeof(*cascade));
1806         cascade->one = one;
1807         cascade->two = two;
1808         cascade->end = cascade->ptr = 0;
1809         cascade->filter.vtbl = &cascade_vtbl;
1810         return (struct stream_filter *)cascade;
1811 }
1812
1813 /*
1814  * ident filter
1815  */
1816 #define IDENT_DRAINING (-1)
1817 #define IDENT_SKIPPING (-2)
1818 struct ident_filter {
1819         struct stream_filter filter;
1820         struct strbuf left;
1821         int state;
1822         char ident[GIT_MAX_HEXSZ + 5]; /* ": x40 $" */
1823 };
1824
1825 static int is_foreign_ident(const char *str)
1826 {
1827         int i;
1828
1829         if (!skip_prefix(str, "$Id: ", &str))
1830                 return 0;
1831         for (i = 0; str[i]; i++) {
1832                 if (isspace(str[i]) && str[i+1] != '$')
1833                         return 1;
1834         }
1835         return 0;
1836 }
1837
1838 static void ident_drain(struct ident_filter *ident, char **output_p, size_t *osize_p)
1839 {
1840         size_t to_drain = ident->left.len;
1841
1842         if (*osize_p < to_drain)
1843                 to_drain = *osize_p;
1844         if (to_drain) {
1845                 memcpy(*output_p, ident->left.buf, to_drain);
1846                 strbuf_remove(&ident->left, 0, to_drain);
1847                 *output_p += to_drain;
1848                 *osize_p -= to_drain;
1849         }
1850         if (!ident->left.len)
1851                 ident->state = 0;
1852 }
1853
1854 static int ident_filter_fn(struct stream_filter *filter,
1855                            const char *input, size_t *isize_p,
1856                            char *output, size_t *osize_p)
1857 {
1858         struct ident_filter *ident = (struct ident_filter *)filter;
1859         static const char head[] = "$Id";
1860
1861         if (!input) {
1862                 /* drain upon eof */
1863                 switch (ident->state) {
1864                 default:
1865                         strbuf_add(&ident->left, head, ident->state);
1866                         /* fallthrough */
1867                 case IDENT_SKIPPING:
1868                         /* fallthrough */
1869                 case IDENT_DRAINING:
1870                         ident_drain(ident, &output, osize_p);
1871                 }
1872                 return 0;
1873         }
1874
1875         while (*isize_p || (ident->state == IDENT_DRAINING)) {
1876                 int ch;
1877
1878                 if (ident->state == IDENT_DRAINING) {
1879                         ident_drain(ident, &output, osize_p);
1880                         if (!*osize_p)
1881                                 break;
1882                         continue;
1883                 }
1884
1885                 ch = *(input++);
1886                 (*isize_p)--;
1887
1888                 if (ident->state == IDENT_SKIPPING) {
1889                         /*
1890                          * Skipping until '$' or LF, but keeping them
1891                          * in case it is a foreign ident.
1892                          */
1893                         strbuf_addch(&ident->left, ch);
1894                         if (ch != '\n' && ch != '$')
1895                                 continue;
1896                         if (ch == '$' && !is_foreign_ident(ident->left.buf)) {
1897                                 strbuf_setlen(&ident->left, sizeof(head) - 1);
1898                                 strbuf_addstr(&ident->left, ident->ident);
1899                         }
1900                         ident->state = IDENT_DRAINING;
1901                         continue;
1902                 }
1903
1904                 if (ident->state < sizeof(head) &&
1905                     head[ident->state] == ch) {
1906                         ident->state++;
1907                         continue;
1908                 }
1909
1910                 if (ident->state)
1911                         strbuf_add(&ident->left, head, ident->state);
1912                 if (ident->state == sizeof(head) - 1) {
1913                         if (ch != ':' && ch != '$') {
1914                                 strbuf_addch(&ident->left, ch);
1915                                 ident->state = 0;
1916                                 continue;
1917                         }
1918
1919                         if (ch == ':') {
1920                                 strbuf_addch(&ident->left, ch);
1921                                 ident->state = IDENT_SKIPPING;
1922                         } else {
1923                                 strbuf_addstr(&ident->left, ident->ident);
1924                                 ident->state = IDENT_DRAINING;
1925                         }
1926                         continue;
1927                 }
1928
1929                 strbuf_addch(&ident->left, ch);
1930                 ident->state = IDENT_DRAINING;
1931         }
1932         return 0;
1933 }
1934
1935 static void ident_free_fn(struct stream_filter *filter)
1936 {
1937         struct ident_filter *ident = (struct ident_filter *)filter;
1938         strbuf_release(&ident->left);
1939         free(filter);
1940 }
1941
1942 static struct stream_filter_vtbl ident_vtbl = {
1943         ident_filter_fn,
1944         ident_free_fn,
1945 };
1946
1947 static struct stream_filter *ident_filter(const struct object_id *oid)
1948 {
1949         struct ident_filter *ident = xmalloc(sizeof(*ident));
1950
1951         xsnprintf(ident->ident, sizeof(ident->ident),
1952                   ": %s $", oid_to_hex(oid));
1953         strbuf_init(&ident->left, 0);
1954         ident->filter.vtbl = &ident_vtbl;
1955         ident->state = 0;
1956         return (struct stream_filter *)ident;
1957 }
1958
1959 /*
1960  * Return an appropriately constructed filter for the path, or NULL if
1961  * the contents cannot be filtered without reading the whole thing
1962  * in-core.
1963  *
1964  * Note that you would be crazy to set CRLF, smudge/clean or ident to a
1965  * large binary blob you would want us not to slurp into the memory!
1966  */
1967 struct stream_filter *get_stream_filter(const struct index_state *istate,
1968                                         const char *path,
1969                                         const struct object_id *oid)
1970 {
1971         struct conv_attrs ca;
1972         struct stream_filter *filter = NULL;
1973
1974         convert_attrs(istate, &ca, path);
1975         if (ca.drv && (ca.drv->process || ca.drv->smudge || ca.drv->clean))
1976                 return NULL;
1977
1978         if (ca.working_tree_encoding)
1979                 return NULL;
1980
1981         if (ca.crlf_action == CRLF_AUTO || ca.crlf_action == CRLF_AUTO_CRLF)
1982                 return NULL;
1983
1984         if (ca.ident)
1985                 filter = ident_filter(oid);
1986
1987         if (output_eol(ca.crlf_action) == EOL_CRLF)
1988                 filter = cascade_filter(filter, lf_to_crlf_filter());
1989         else
1990                 filter = cascade_filter(filter, &null_filter_singleton);
1991
1992         return filter;
1993 }
1994
1995 void free_stream_filter(struct stream_filter *filter)
1996 {
1997         filter->vtbl->free(filter);
1998 }
1999
2000 int stream_filter(struct stream_filter *filter,
2001                   const char *input, size_t *isize_p,
2002                   char *output, size_t *osize_p)
2003 {
2004         return filter->vtbl->filter(filter, input, isize_p, output, osize_p);
2005 }
2006
2007 void init_checkout_metadata(struct checkout_metadata *meta, const char *refname,
2008                             const struct object_id *treeish,
2009                             const struct object_id *blob)
2010 {
2011         memset(meta, 0, sizeof(*meta));
2012         if (refname)
2013                 meta->refname = refname;
2014         if (treeish)
2015                 oidcpy(&meta->treeish, treeish);
2016         if (blob)
2017                 oidcpy(&meta->blob, blob);
2018 }
2019
2020 void clone_checkout_metadata(struct checkout_metadata *dst,
2021                              const struct checkout_metadata *src,
2022                              const struct object_id *blob)
2023 {
2024         memcpy(dst, src, sizeof(*dst));
2025         if (blob)
2026                 oidcpy(&dst->blob, blob);
2027 }