lib/patch.c

   1 /*
   2  * Copyright (c) 2022 Omar Polo <op@openbsd.org>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  *
  16  * Apply patches.
  17  *
  18  * Things that we may want to support:
  19  *     + support indented patches?
  20  *     + support other kinds of patches?
  21  */
  22 #include "got_compat.h"
  23
  24 #include <sys/types.h>
  25 #include <sys/queue.h>
  26 #include <sys/socket.h>
  27 #include <sys/stat.h>
  28 #include <sys/uio.h>
  29
  30 #include <ctype.h>
  31 #include <errno.h>
  32 #include <limits.h>
  33 #include <stdint.h>
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <unistd.h>
  38
  39 #include "got_error.h"
  40 #include "got_object.h"
  41 #include "got_path.h"
  42 #include "got_reference.h"
  43 #include "got_cancel.h"
  44 #include "got_worktree.h"
  45 #include "got_repository.h"
  46 #include "got_opentemp.h"
  47 #include "got_patch.h"
  48 #include "got_diff.h"
  49
  50 #include "got_lib_delta.h"
  51 #include "got_lib_diff.h"
  52 #include "got_lib_object.h"
  53 #include "got_lib_privsep.h"
  54 #include "got_lib_hash.h"
  55
  56 #ifndef MIN
  57 #define MIN(a, b) ((a) < (b) ? (a) : (b))
  58 #endif
  59
  60 struct got_patch_hunk {
  61         STAILQ_ENTRY(got_patch_hunk) entries;
  62         const struct got_error *err;
  63         int     ws_mangled;
  64         int     offset;
  65         int     old_nonl;
  66         int     new_nonl;
  67         int     old_from;
  68         int     old_lines;
  69         int     new_from;
  70         int     new_lines;
  71         size_t  len;
  72         size_t  cap;
  73         char    **lines;
  74 };
  75
  76 STAILQ_HEAD(got_patch_hunk_head, got_patch_hunk);
  77 struct got_patch {
  78         int      xbit;
  79         char    *old;
  80         char    *new;
  81         char     cid[41];
  82         char     blob[41];
  83         struct got_patch_hunk_head head;
  84 };
  85
  86 struct patch_args {
  87         got_patch_progress_cb progress_cb;
  88         void    *progress_arg;
  89         struct got_patch_hunk_head *head;
  90 };
  91
  92 static mode_t
  93 apply_umask(mode_t mode)
  94 {
  95         mode_t um;
  96
  97         um = umask(000);
  98         umask(um);
  99         return mode & ~um;
 100 }
 101
 102 static const struct got_error *
 103 send_patch(struct imsgbuf *ibuf, int fd)
 104 {
 105         const struct got_error *err = NULL;
 106
 107         if (imsg_compose(ibuf, GOT_IMSG_PATCH_FILE, 0, 0, fd,
 108             NULL, 0) == -1) {
 109                 err = got_error_from_errno(
 110                     "imsg_compose GOT_IMSG_PATCH_FILE");
 111                 close(fd);
 112                 return err;
 113         }
 114
 115         return got_privsep_flush_imsg(ibuf);
 116 }
 117
 118 static void
 119 patch_free(struct got_patch *p)
 120 {
 121         struct got_patch_hunk *h;
 122         size_t i;
 123
 124         while (!STAILQ_EMPTY(&p->head)) {
 125                 h = STAILQ_FIRST(&p->head);
 126                 STAILQ_REMOVE_HEAD(&p->head, entries);
 127
 128                 for (i = 0; i < h->len; ++i)
 129                         free(h->lines[i]);
 130                 free(h->lines);
 131                 free(h);
 132         }
 133
 134         free(p->new);
 135         free(p->old);
 136
 137         memset(p, 0, sizeof(*p));
 138         STAILQ_INIT(&p->head);
 139 }
 140
 141 static const struct got_error *
 142 pushline(struct got_patch_hunk *h, const char *line)
 143 {
 144         void    *t;
 145         size_t   newcap;
 146
 147         if (h->len == h->cap) {
 148                 if ((newcap = h->cap * 1.5) == 0)
 149                         newcap = 16;
 150                 t = recallocarray(h->lines, h->cap, newcap,
 151                     sizeof(h->lines[0]));
 152                 if (t == NULL)
 153                         return got_error_from_errno("recallocarray");
 154                 h->lines = t;
 155                 h->cap = newcap;
 156         }
 157
 158         if ((t = strdup(line)) == NULL)
 159                 return got_error_from_errno("strdup");
 160
 161         h->lines[h->len++] = t;
 162         return NULL;
 163 }
 164
 165 static const struct got_error *
 166 recv_patch(struct imsgbuf *ibuf, int *done, struct got_patch *p, int strip)
 167 {
 168         const struct got_error *err = NULL;
 169         struct imsg imsg;
 170         struct got_imsg_patch_hunk hdr;
 171         struct got_imsg_patch patch;
 172         struct got_patch_hunk *h = NULL;
 173         size_t datalen;
 174         int lastmode = -1;
 175
 176         memset(p, 0, sizeof(*p));
 177         STAILQ_INIT(&p->head);
 178
 179         err = got_privsep_recv_imsg(&imsg, ibuf, 0);
 180         if (err)
 181                 return err;
 182         if (imsg.hdr.type == GOT_IMSG_PATCH_EOF) {
 183                 *done = 1;
 184                 goto done;
 185         }
 186         if (imsg.hdr.type != GOT_IMSG_PATCH) {
 187                 err = got_error(GOT_ERR_PRIVSEP_MSG);
 188                 goto done;
 189         }
 190         datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
 191         if (datalen != sizeof(patch)) {
 192                 err = got_error(GOT_ERR_PRIVSEP_LEN);
 193                 goto done;
 194         }
 195         memcpy(&patch, imsg.data, sizeof(patch));
 196
 197         if (patch.old[sizeof(patch.old)-1] != '\0' ||
 198             patch.new[sizeof(patch.new)-1] != '\0' ||
 199             patch.cid[sizeof(patch.cid)-1] != '\0' ||
 200             patch.blob[sizeof(patch.blob)-1] != '\0') {
 201                 err = got_error(GOT_ERR_PRIVSEP_LEN);
 202                 goto done;
 203         }
 204
 205         if (*patch.cid != '\0')
 206                 strlcpy(p->cid, patch.cid, sizeof(p->cid));
 207
 208         if (*patch.blob != '\0')
 209                 strlcpy(p->blob, patch.blob, sizeof(p->blob));
 210
 211         p->xbit = patch.xbit;
 212
 213         /* automatically set strip=1 for git-style diffs */
 214         if (strip == -1 && patch.git &&
 215             (*patch.old == '\0' || !strncmp(patch.old, "a/", 2)) &&
 216             (*patch.new == '\0' || !strncmp(patch.new, "b/", 2)))
 217                 strip = 1;
 218
 219         /* prefer the new name if not /dev/null for not git-style diffs */
 220         if (!patch.git && *patch.new != '\0' && *patch.old != '\0') {
 221                 err = got_path_strip(&p->old, patch.new, strip);
 222                 if (err)
 223                         goto done;
 224         } else if (*patch.old != '\0') {
 225                 err = got_path_strip(&p->old, patch.old, strip);
 226                 if (err)
 227                         goto done;
 228         }
 229
 230         if (*patch.new != '\0') {
 231                 err = got_path_strip(&p->new, patch.new, strip);
 232                 if (err)
 233                         goto done;
 234         }
 235
 236         if (p->old == NULL && p->new == NULL) {
 237                 err = got_error(GOT_ERR_PATCH_MALFORMED);
 238                 goto done;
 239         }
 240
 241         imsg_free(&imsg);
 242
 243         for (;;) {
 244                 char *t;
 245
 246                 err = got_privsep_recv_imsg(&imsg, ibuf, 0);
 247                 if (err) {
 248                         patch_free(p);
 249                         return err;
 250                 }
 251
 252                 datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
 253                 switch (imsg.hdr.type) {
 254                 case GOT_IMSG_PATCH_DONE:
 255                         if (h != NULL && h->len == 0)
 256                                 err = got_error(GOT_ERR_PATCH_MALFORMED);
 257                         goto done;
 258                 case GOT_IMSG_PATCH_HUNK:
 259                         if (h != NULL &&
 260                             (h->len == 0 || h->old_nonl || h->new_nonl)) {
 261                                 err = got_error(GOT_ERR_PATCH_MALFORMED);
 262                                 goto done;
 263                         }
 264                         lastmode = -1;
 265                         if (datalen != sizeof(hdr)) {
 266                                 err = got_error(GOT_ERR_PRIVSEP_LEN);
 267                                 goto done;
 268                         }
 269                         memcpy(&hdr, imsg.data, sizeof(hdr));
 270                         if (hdr.oldfrom < 0 || hdr.newfrom < 0) {
 271                                 err = got_error(GOT_ERR_PRIVSEP_LEN);
 272                                 goto done;
 273                         }
 274                         if ((h = calloc(1, sizeof(*h))) == NULL) {
 275                                 err = got_error_from_errno("calloc");
 276                                 goto done;
 277                         }
 278                         h->old_from = hdr.oldfrom;
 279                         h->old_lines = hdr.oldlines;
 280                         h->new_from = hdr.newfrom;
 281                         h->new_lines = hdr.newlines;
 282                         STAILQ_INSERT_TAIL(&p->head, h, entries);
 283                         break;
 284                 case GOT_IMSG_PATCH_LINE:
 285                         if (h == NULL) {
 286                                 err = got_error(GOT_ERR_PRIVSEP_MSG);
 287                                 goto done;
 288                         }
 289                         t = imsg.data;
 290                         /* at least one char */
 291                         if (datalen < 2 || t[datalen-1] != '\0') {
 292                                 err = got_error(GOT_ERR_PRIVSEP_MSG);
 293                                 goto done;
 294                         }
 295                         if (*t != ' ' && *t != '-' && *t != '+' &&
 296                             *t != '\\') {
 297                                 err = got_error(GOT_ERR_PRIVSEP_MSG);
 298                                 goto done;
 299                         }
 300
 301                         if (*t != '\\')
 302                                 err = pushline(h, t);
 303                         else if (lastmode == '-')
 304                                 h->old_nonl = 1;
 305                         else if (lastmode == '+')
 306                                 h->new_nonl = 1;
 307                         else
 308                                 err = got_error(GOT_ERR_PATCH_MALFORMED);
 309
 310                         if (err)
 311                                 goto done;
 312
 313                         lastmode = *t;
 314                         break;
 315                 default:
 316                         err = got_error(GOT_ERR_PRIVSEP_MSG);
 317                         goto done;
 318                 }
 319
 320                 imsg_free(&imsg);
 321         }
 322
 323 done:
 324         if (err)
 325                 patch_free(p);
 326
 327         imsg_free(&imsg);
 328         return err;
 329 }
 330
 331 static void
 332 reverse_patch(struct got_patch *p)
 333 {
 334         struct got_patch_hunk *h;
 335         size_t i;
 336         int tmp;
 337
 338         STAILQ_FOREACH(h, &p->head, entries) {
 339                 tmp = h->old_from;
 340                 h->old_from = h->new_from;
 341                 h->new_from = tmp;
 342
 343                 tmp = h->old_lines;
 344                 h->old_lines = h->new_lines;
 345                 h->new_lines = tmp;
 346
 347                 tmp = h->old_nonl;
 348                 h->old_nonl = h->new_nonl;
 349                 h->new_nonl = tmp;
 350
 351                 for (i = 0; i < h->len; ++i) {
 352                         if (*h->lines[i] == '+')
 353                                 *h->lines[i] = '-';
 354                         else if (*h->lines[i] == '-')
 355                                 *h->lines[i] = '+';
 356                 }
 357         }
 358 }
 359
 360 /*
 361  * Copy data from orig starting at copypos until pos into tmp.
 362  * If pos is -1, copy until EOF.
 363  */
 364 static const struct got_error *
 365 copy(FILE *tmp, FILE *orig, off_t copypos, off_t pos)
 366 {
 367         char buf[BUFSIZ];
 368         size_t len, r, w;
 369
 370         if (fseeko(orig, copypos, SEEK_SET) == -1)
 371                 return got_error_from_errno("fseeko");
 372
 373         while (pos == -1 || copypos < pos) {
 374                 len = sizeof(buf);
 375                 if (pos > 0)
 376                         len = MIN(len, (size_t)pos - copypos);
 377                 r = fread(buf, 1, len, orig);
 378                 if (r != len && ferror(orig))
 379                         return got_error_from_errno("fread");
 380                 w = fwrite(buf, 1, r, tmp);
 381                 if (w != r)
 382                         return got_error_from_errno("fwrite");
 383                 copypos += len;
 384                 if (r != len && feof(orig)) {
 385                         if (pos == -1)
 386                                 return NULL;
 387                         return got_error(GOT_ERR_HUNK_FAILED);
 388                 }
 389         }
 390         return NULL;
 391 }
 392
 393 static int linecmp(const char *, const char *, int *);
 394
 395 static const struct got_error *
 396 locate_hunk(FILE *orig, struct got_patch_hunk *h, off_t *pos, int *lineno)
 397 {
 398         const struct got_error *err = NULL;
 399         char *line = NULL;
 400         char mode = *h->lines[0];
 401         size_t linesize = 0;
 402         ssize_t linelen;
 403         off_t match = -1;
 404         int mangled = 0, match_lineno = -1;
 405
 406         for (;;) {
 407                 linelen = getline(&line, &linesize, orig);
 408                 if (linelen == -1) {
 409                         if (ferror(orig))
 410                                 err = got_error_from_errno("getline");
 411                         else if (match == -1)
 412                                 err = got_error(GOT_ERR_HUNK_FAILED);
 413                         break;
 414                 }
 415                 if (line[linelen - 1] == '\n')
 416                         line[linelen - 1] = '\0';
 417                 (*lineno)++;
 418
 419                 if ((mode == ' ' && !linecmp(h->lines[0] + 1, line, &mangled)) ||
 420                     (mode == '-' && !linecmp(h->lines[0] + 1, line, &mangled)) ||
 421                     (mode == '+' && *lineno == h->old_from)) {
 422                         match = ftello(orig);
 423                         if (match == -1) {
 424                                 err = got_error_from_errno("ftello");
 425                                 break;
 426                         }
 427                         match -= linelen;
 428                         match_lineno = (*lineno)-1;
 429                 }
 430
 431                 if (*lineno >= h->old_from && match != -1) {
 432                         if (mangled)
 433                                 h->ws_mangled = 1;
 434                         break;
 435                 }
 436         }
 437
 438         if (err == NULL) {
 439                 *pos = match;
 440                 *lineno = match_lineno;
 441                 if (fseeko(orig, match, SEEK_SET) == -1)
 442                         err = got_error_from_errno("fseeko");
 443         }
 444
 445         free(line);
 446         return err;
 447 }
 448
 449 static int
 450 linecmp(const char *a, const char *b, int *mangled)
 451 {
 452         int c;
 453
 454         *mangled = 0;
 455         c = strcmp(a, b);
 456         if (c == 0)
 457                 return c;
 458
 459         *mangled = 1;
 460         for (;;) {
 461                 while (*a == '\t' || *a == ' ' || *a == '\f')
 462                         a++;
 463                 while (*b == '\t' || *b == ' ' || *b == '\f')
 464                         b++;
 465                 if (*a == '\0' || *a != *b)
 466                         break;
 467                 a++, b++;
 468         }
 469
 470         return *a - *b;
 471 }
 472
 473 static const struct got_error *
 474 test_hunk(FILE *orig, struct got_patch_hunk *h)
 475 {
 476         const struct got_error *err = NULL;
 477         char *line = NULL;
 478         size_t linesize = 0, i = 0;
 479         ssize_t linelen;
 480         int mangled;
 481
 482         for (i = 0; i < h->len; ++i) {
 483                 switch (*h->lines[i]) {
 484                 case '+':
 485                         continue;
 486                 case ' ':
 487                 case '-':
 488                         linelen = getline(&line, &linesize, orig);
 489                         if (linelen == -1) {
 490                                 if (ferror(orig))
 491                                         err = got_error_from_errno("getline");
 492                                 else
 493                                         err = got_error(
 494                                             GOT_ERR_HUNK_FAILED);
 495                                 goto done;
 496                         }
 497                         if (line[linelen - 1] == '\n')
 498                                 line[linelen - 1] = '\0';
 499                         if (linecmp(h->lines[i] + 1, line, &mangled)) {
 500                                 err = got_error(GOT_ERR_HUNK_FAILED);
 501                                 goto done;
 502                         }
 503                         if (mangled)
 504                                 h->ws_mangled = 1;
 505                         break;
 506                 }
 507         }
 508
 509 done:
 510         free(line);
 511         return err;
 512 }
 513
 514 static const struct got_error *
 515 apply_hunk(FILE *orig, FILE *tmp, struct got_patch_hunk *h, int *lineno,
 516     off_t from)
 517 {
 518         const struct got_error *err = NULL;
 519         const char *t;
 520         size_t linesize = 0, i, new = 0;
 521         char *line = NULL;
 522         char mode;
 523         ssize_t linelen;
 524
 525         if (orig != NULL && fseeko(orig, from, SEEK_SET) == -1)
 526                 return got_error_from_errno("fseeko");
 527
 528         for (i = 0; i < h->len; ++i) {
 529                 switch (mode = *h->lines[i]) {
 530                 case '-':
 531                 case ' ':
 532                         (*lineno)++;
 533                         if (orig != NULL) {
 534                                 linelen = getline(&line, &linesize, orig);
 535                                 if (linelen == -1) {
 536                                         err = got_error_from_errno("getline");
 537                                         goto done;
 538                                 }
 539                                 if (line[linelen - 1] == '\n')
 540                                         line[linelen - 1] = '\0';
 541                                 t = line;
 542                         } else
 543                                 t = h->lines[i] + 1;
 544                         if (mode == '-')
 545                                 continue;
 546                         if (fprintf(tmp, "%s\n", t) < 0) {
 547                                 err = got_error_from_errno("fprintf");
 548                                 goto done;
 549                         }
 550                         break;
 551                 case '+':
 552                         new++;
 553                         if (fprintf(tmp, "%s", h->lines[i] + 1) < 0) {
 554                                 err = got_error_from_errno("fprintf");
 555                                 goto done;
 556                         }
 557                         if (new != h->new_lines || !h->new_nonl) {
 558                                 if (fprintf(tmp, "\n") < 0) {
 559                                         err = got_error_from_errno("fprintf");
 560                                         goto done;
 561                                 }
 562                         }
 563                         break;
 564                 }
 565         }
 566
 567 done:
 568         free(line);
 569         return err;
 570 }
 571
 572 static const struct got_error *
 573 patch_file(struct got_patch *p, FILE *orig, FILE *tmp)
 574 {
 575         const struct got_error *err = NULL;
 576         struct got_patch_hunk *h;
 577         struct stat sb;
 578         int lineno = 0;
 579         off_t copypos, pos;
 580         char *line = NULL;
 581         size_t linesize = 0;
 582         ssize_t linelen;
 583
 584         if (p->old == NULL) {                           /* create */
 585                 h = STAILQ_FIRST(&p->head);
 586                 if (h == NULL || STAILQ_NEXT(h, entries) != NULL)
 587                         return got_error(GOT_ERR_PATCH_MALFORMED);
 588                 return apply_hunk(orig, tmp, h, &lineno, 0);
 589         }
 590
 591         /* When deleting binary files there are no hunks to apply. */
 592         if (p->new == NULL && STAILQ_EMPTY(&p->head))
 593                 return NULL;
 594
 595         if (fstat(fileno(orig), &sb) == -1)
 596                 return got_error_from_errno("fstat");
 597
 598         copypos = 0;
 599         STAILQ_FOREACH(h, &p->head, entries) {
 600         tryagain:
 601                 err = locate_hunk(orig, h, &pos, &lineno);
 602                 if (err != NULL && err->code == GOT_ERR_HUNK_FAILED)
 603                         h->err = err;
 604                 if (err != NULL)
 605                         return err;
 606                 err = copy(tmp, orig, copypos, pos);
 607                 if (err != NULL)
 608                         return err;
 609                 copypos = pos;
 610
 611                 err = test_hunk(orig, h);
 612                 if (err != NULL && err->code == GOT_ERR_HUNK_FAILED) {
 613                         /*
 614                          * try to apply the hunk again starting the search
 615                          * after the previous partial match.
 616                          */
 617                         if (fseeko(orig, pos, SEEK_SET) == -1)
 618                                 return got_error_from_errno("fseeko");
 619                         linelen = getline(&line, &linesize, orig);
 620                         if (linelen == -1)
 621                                 return got_error_from_errno("getline");
 622                         lineno++;
 623                         goto tryagain;
 624                 }
 625                 if (err != NULL)
 626                         return err;
 627
 628                 if (lineno + 1 != h->old_from)
 629                         h->offset = lineno + 1 - h->old_from;
 630
 631                 err = apply_hunk(orig, tmp, h, &lineno, pos);
 632                 if (err != NULL)
 633                         return err;
 634
 635                 copypos = ftello(orig);
 636                 if (copypos == -1)
 637                         return got_error_from_errno("ftello");
 638         }
 639
 640         if (p->new == NULL && sb.st_size != copypos) {
 641                 h = STAILQ_FIRST(&p->head);
 642                 h->err = got_error(GOT_ERR_HUNK_FAILED);
 643                 err = h->err;
 644         } else if (!feof(orig))
 645                 err = copy(tmp, orig, copypos, -1);
 646
 647         return err;
 648 }
 649
 650 static const struct got_error *
 651 report_progress(struct patch_args *pa, const char *old, const char *new,
 652     unsigned char status, const struct got_error *orig_error)
 653 {
 654         const struct got_error *err;
 655         struct got_patch_hunk *h;
 656
 657         err = pa->progress_cb(pa->progress_arg, old, new, status,
 658             orig_error, 0, 0, 0, 0, 0, 0, NULL);
 659         if (err)
 660                 return err;
 661
 662         STAILQ_FOREACH(h, pa->head, entries) {
 663                 if (h->offset == 0 && !h->ws_mangled && h->err == NULL)
 664                         continue;
 665
 666                 err = pa->progress_cb(pa->progress_arg, old, new, 0, NULL,
 667                     h->old_from, h->old_lines, h->new_from, h->new_lines,
 668                     h->offset, h->ws_mangled, h->err);
 669                 if (err)
 670                         return err;
 671         }
 672
 673         return NULL;
 674 }
 675
 676 static const struct got_error *
 677 patch_delete(void *arg, unsigned char status, unsigned char staged_status,
 678     const char *path)
 679 {
 680         return report_progress(arg, path, NULL, status, NULL);
 681 }
 682
 683 static const struct got_error *
 684 patch_add(void *arg, unsigned char status, const char *path)
 685 {
 686         return report_progress(arg, NULL, path, status, NULL);
 687 }
 688
 689 static const struct got_error *
 690 open_blob(char **path, FILE **fp, const char *blobid,
 691     struct got_repository *repo)
 692 {
 693         const struct got_error *err = NULL;
 694         struct got_blob_object *blob = NULL;
 695         struct got_object_id id, *idptr, *matched_id = NULL;
 696         int fd = -1;
 697
 698         *fp = NULL;
 699         *path = NULL;
 700
 701         if (strlen(blobid) != SHA1_DIGEST_STRING_LENGTH - 1) {
 702                 err = got_repo_match_object_id(&matched_id, NULL, blobid,
 703                     GOT_OBJ_TYPE_BLOB, NULL /* do not resolve tags */,
 704                     repo);
 705                 if (err)
 706                         return err;
 707                 idptr = matched_id;
 708         } else {
 709                 if (!got_parse_object_id(&id, blobid, GOT_HASH_SHA1))
 710                         return got_error(GOT_ERR_BAD_OBJ_ID_STR);
 711                 idptr = &id;
 712         }
 713
 714         fd = got_opentempfd();
 715         if (fd == -1) {
 716                 err = got_error_from_errno("got_opentempfd");
 717                 goto done;
 718         }
 719
 720         err = got_object_open_as_blob(&blob, repo, idptr, 8192, fd);
 721         if (err)
 722                 goto done;
 723
 724         err = got_opentemp_named(path, fp, GOT_TMPDIR_STR "/got-patch-blob",
 725             "");
 726         if (err)
 727                 goto done;
 728
 729         err = got_object_blob_dump_to_file(NULL, NULL, NULL, *fp, blob);
 730         if (err)
 731                 goto done;
 732
 733 done:
 734         if (fd != -1 && close(fd) == -1 && err == NULL)
 735                 err = got_error_from_errno("close");
 736         if (blob)
 737                 got_object_blob_close(blob);
 738         if (matched_id != NULL)
 739                 free(matched_id);
 740         if (err) {
 741                 if (*fp != NULL)
 742                         fclose(*fp);
 743                 if (*path != NULL)
 744                         unlink(*path);
 745                 free(*path);
 746                 *fp = NULL;
 747                 *path = NULL;
 748         }
 749         return err;
 750 }
 751
 752 static const struct got_error *
 753 prepare_merge(int *do_merge, char **apath, FILE **afile,
 754     struct got_worktree *worktree, struct got_repository *repo,
 755     struct got_patch *p, struct got_object_id *commit_id,
 756     struct got_tree_object *tree, const char *path)
 757 {
 758         const struct got_error *err = NULL;
 759
 760         *do_merge = 0;
 761         *apath = NULL;
 762         *afile = NULL;
 763
 764         /* don't run the diff3 merge on creations/deletions */
 765         if (p->old == NULL || p->new == NULL)
 766                 return NULL;
 767
 768         if (commit_id) {
 769                 struct got_object_id *id;
 770
 771                 err = got_object_tree_find_path(&id, NULL, repo, tree, path);
 772                 if (err)
 773                         return err;
 774                 got_sha1_digest_to_str(id->sha1, p->blob, sizeof(p->blob));
 775                 got_sha1_digest_to_str(commit_id->sha1, p->cid, sizeof(p->cid));
 776                 free(id);
 777                 err = open_blob(apath, afile, p->blob, repo);
 778                 *do_merge = err == NULL;
 779         } else if (*p->blob != '\0') {
 780                 err = open_blob(apath, afile, p->blob, repo);
 781                 /*
 782                  * ignore failures to open this blob, we might have
 783                  * parsed gibberish.
 784                  */
 785                 if (err && !(err->code == GOT_ERR_ERRNO && errno == ENOENT) &&
 786                     err->code != GOT_ERR_NO_OBJ)
 787                         return err;
 788                 *do_merge = err == NULL;
 789                 err = NULL;
 790         }
 791
 792         return err;
 793 }
 794
 795 static const struct got_error *
 796 apply_patch(int *overlapcnt, struct got_worktree *worktree,
 797     struct got_repository *repo, struct got_fileindex *fileindex,
 798     const char *old, const char *new, struct got_patch *p, int nop,
 799     int reverse, struct got_object_id *commit_id,
 800     struct got_tree_object *tree, struct patch_args *pa,
 801     got_cancel_cb cancel_cb, void *cancel_arg)
 802 {
 803         const struct got_error *err = NULL;
 804         struct stat sb;
 805         int do_merge = 0, file_renamed = 0;
 806         char *oldlabel = NULL, *newlabel = NULL, *anclabel = NULL;
 807         char *oldpath = NULL, *newpath = NULL;
 808         char *tmppath = NULL, *template = NULL;
 809         char *apath = NULL, *mergepath = NULL;
 810         FILE *oldfile = NULL, *tmpfile = NULL, *afile = NULL, *mergefile = NULL;
 811         int outfd;
 812         mode_t mode = GOT_DEFAULT_FILE_MODE;
 813
 814         *overlapcnt = 0;
 815
 816         err = prepare_merge(&do_merge, &apath, &afile, worktree, repo, p,
 817             commit_id, tree, old);
 818         if (err)
 819                 return err;
 820
 821         if (reverse && !do_merge)
 822                 reverse_patch(p);
 823
 824         if (asprintf(&oldpath, "%s/%s", got_worktree_get_root_path(worktree),
 825             old) == -1) {
 826                 err = got_error_from_errno("asprintf");
 827                 goto done;
 828         }
 829
 830         if (asprintf(&newpath, "%s/%s", got_worktree_get_root_path(worktree),
 831             new) == -1) {
 832                 err = got_error_from_errno("asprintf");
 833                 goto done;
 834         }
 835
 836         file_renamed = strcmp(oldpath, newpath);
 837
 838         if (asprintf(&template, "%s/got-patch",
 839             got_worktree_get_root_path(worktree)) == -1) {
 840                 err = got_error_from_errno(template);
 841                 goto done;
 842         }
 843
 844         if (p->old != NULL) {
 845                 if ((oldfile = fopen(oldpath, "r")) == NULL) {
 846                         err = got_error_from_errno2("open", oldpath);
 847                         goto done;
 848                 }
 849                 if (fstat(fileno(oldfile), &sb) == -1) {
 850                         err = got_error_from_errno2("fstat", oldpath);
 851                         goto done;
 852                 }
 853                 mode = sb.st_mode;
 854         } else if (p->xbit)
 855                 mode |= (S_IXUSR | S_IXGRP | S_IXOTH);
 856
 857         err = got_opentemp_named(&tmppath, &tmpfile, template, "");
 858         if (err)
 859                 goto done;
 860         outfd = fileno(tmpfile);
 861         err = patch_file(p, afile != NULL ? afile : oldfile, tmpfile);
 862         if (err)
 863                 goto done;
 864
 865         if (do_merge) {
 866                 const char *type, *id;
 867
 868                 if (fseeko(afile, 0, SEEK_SET) == -1 ||
 869                     fseeko(oldfile, 0, SEEK_SET) == -1 ||
 870                     fseeko(tmpfile, 0, SEEK_SET) == -1) {
 871                         err = got_error_from_errno("fseeko");
 872                         goto done;
 873                 }
 874
 875                 if (asprintf(&oldlabel, "--- %s", p->old) == -1) {
 876                         err = got_error_from_errno("asprintf");
 877                         oldlabel = NULL;
 878                         goto done;
 879                 }
 880
 881                 if (asprintf(&newlabel, "+++ %s", p->new) == -1) {
 882                         err = got_error_from_errno("asprintf");
 883                         newlabel = NULL;
 884                         goto done;
 885                 }
 886
 887                 if (*p->cid != '\0') {
 888                         type = "commit";
 889                         id = p->cid;
 890                 } else {
 891                         type = "blob";
 892                         id = p->blob;
 893                 }
 894
 895                 if (asprintf(&anclabel, "%s %s", type, id) == -1) {
 896                         err = got_error_from_errno("asprintf");
 897                         anclabel = NULL;
 898                         goto done;
 899                 }
 900
 901                 if (reverse) {
 902                         char *s;
 903                         FILE *t;
 904
 905                         s = anclabel;
 906                         anclabel = newlabel;
 907                         newlabel = s;
 908
 909                         t = afile;
 910                         afile = tmpfile;
 911                         tmpfile = t;
 912                 }
 913
 914                 err = got_opentemp_named(&mergepath, &mergefile, template, "");
 915                 if (err)
 916                         goto done;
 917                 outfd = fileno(mergefile);
 918
 919                 err = got_merge_diff3(overlapcnt, outfd, tmpfile, afile,
 920                     oldfile, oldlabel, anclabel, newlabel,
 921                     GOT_DIFF_ALGORITHM_PATIENCE);
 922                 if (err)
 923                         goto done;
 924         }
 925
 926         if (nop)
 927                 goto done;
 928
 929         if (p->old != NULL && p->new == NULL) {
 930                 err = got_worktree_patch_schedule_rm(old, repo, worktree,
 931                     fileindex, patch_delete, pa);
 932                 goto done;
 933         }
 934
 935         if (fchmod(outfd, apply_umask(mode)) == -1) {
 936                 err = got_error_from_errno2("chmod", tmppath);
 937                 goto done;
 938         }
 939
 940         if (mergepath) {
 941                 err = got_path_move_file(mergepath, newpath);
 942                 if (err)
 943                         goto done;
 944                 free(mergepath);
 945                 mergepath = NULL;
 946         } else {
 947                 err = got_path_move_file(tmppath, newpath);
 948                 if (err)
 949                         goto done;
 950                 free(tmppath);
 951                 tmppath = NULL;
 952         }
 953
 954         if (file_renamed) {
 955                 err = got_worktree_patch_schedule_rm(old, repo, worktree,
 956                     fileindex, patch_delete, pa);
 957                 if (err == NULL)
 958                         err = got_worktree_patch_schedule_add(new, repo,
 959                             worktree, fileindex, patch_add,
 960                             pa);
 961                 if (err)
 962                         unlink(newpath);
 963         } else if (p->old == NULL) {
 964                 err = got_worktree_patch_schedule_add(new, repo, worktree,
 965                     fileindex, patch_add, pa);
 966                 if (err)
 967                         unlink(newpath);
 968         } else if (*overlapcnt != 0)
 969                 err = report_progress(pa, old, new, GOT_STATUS_CONFLICT, NULL);
 970         else if (do_merge)
 971                 err = report_progress(pa, old, new, GOT_STATUS_MERGE, NULL);
 972         else
 973                 err = report_progress(pa, old, new, GOT_STATUS_MODIFY, NULL);
 974
 975 done:
 976         free(template);
 977
 978         if (tmppath != NULL && unlink(tmppath) == -1 && err == NULL)
 979                 err = got_error_from_errno("unlink");
 980         if (tmpfile != NULL && fclose(tmpfile) == EOF && err == NULL)
 981                 err = got_error_from_errno("fclose");
 982         free(tmppath);
 983
 984         free(oldpath);
 985         if (oldfile != NULL && fclose(oldfile) == EOF && err == NULL)
 986                 err = got_error_from_errno("fclose");
 987
 988         if (apath != NULL && unlink(apath) == -1 && err == NULL)
 989                 err = got_error_from_errno("unlink");
 990         if (afile != NULL && fclose(afile) == EOF && err == NULL)
 991                 err = got_error_from_errno("fclose");
 992         free(apath);
 993
 994         if (mergepath != NULL && unlink(mergepath) == -1 && err == NULL)
 995                 err = got_error_from_errno("unlink");
 996         if (mergefile != NULL && fclose(mergefile) == EOF && err == NULL)
 997                 err = got_error_from_errno("fclose");
 998         free(mergepath);
 999
1000         free(newpath);
1001         free(oldlabel);
1002         free(newlabel);
1003         free(anclabel);
1004         return err;
1005 }
1006
1007 const struct got_error *
1008 got_patch(int fd, struct got_worktree *worktree, struct got_repository *repo,
1009     int nop, int strip, int reverse, struct got_object_id *commit_id,
1010     got_patch_progress_cb progress_cb, void *progress_arg,
1011     got_cancel_cb cancel_cb, void *cancel_arg)
1012 {
1013         const struct got_error *err = NULL, *complete_err = NULL;
1014         struct got_fileindex *fileindex = NULL;
1015         struct got_commit_object *commit = NULL;
1016         struct got_tree_object *tree = NULL;
1017         char *fileindex_path = NULL;
1018         char *oldpath, *newpath;
1019         struct imsgbuf *ibuf;
1020         int imsg_fds[2] = {-1, -1};
1021         int overlapcnt, done = 0, failed = 0;
1022         pid_t pid;
1023
1024         ibuf = calloc(1, sizeof(*ibuf));
1025         if (ibuf == NULL) {
1026                 err = got_error_from_errno("calloc");
1027                 goto done;
1028         }
1029
1030         if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
1031                 err = got_error_from_errno("socketpair");
1032                 goto done;
1033         }
1034
1035         pid = fork();
1036         if (pid == -1) {
1037                 err = got_error_from_errno("fork");
1038                 goto done;
1039         } else if (pid == 0) {
1040                 got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PATCH,
1041                     NULL);
1042                 /* not reached */
1043         }
1044
1045         if (close(imsg_fds[1]) == -1) {
1046                 err = got_error_from_errno("close");
1047                 goto done;
1048         }
1049         imsg_fds[1] = -1;
1050         imsg_init(ibuf, imsg_fds[0]);
1051
1052         err = send_patch(ibuf, fd);
1053         fd = -1;
1054         if (err)
1055                 goto done;
1056
1057         err = got_worktree_patch_prepare(&fileindex, &fileindex_path,
1058             worktree);
1059         if (err)
1060                 goto done;
1061
1062         if (commit_id) {
1063                 err = got_object_open_as_commit(&commit, repo, commit_id);
1064                 if (err)
1065                         goto done;
1066
1067                 err = got_object_open_as_tree(&tree, repo, commit->tree_id);
1068                 if (err)
1069                         goto done;
1070         }
1071
1072         while (!done && err == NULL) {
1073                 struct got_patch p;
1074                 struct patch_args pa;
1075
1076                 pa.progress_cb = progress_cb;
1077                 pa.progress_arg = progress_arg;
1078                 pa.head = &p.head;
1079
1080                 err = recv_patch(ibuf, &done, &p, strip);
1081                 if (err || done)
1082                         break;
1083
1084                 err = got_worktree_patch_check_path(p.old, p.new, &oldpath,
1085                     &newpath, worktree, repo, fileindex);
1086                 if (err == NULL)
1087                         err = apply_patch(&overlapcnt, worktree, repo,
1088                             fileindex, oldpath, newpath, &p, nop, reverse,
1089                             commit_id, tree, &pa, cancel_cb, cancel_arg);
1090                 if (err != NULL) {
1091                         failed = 1;
1092                         /* recoverable errors */
1093                         if (err->code == GOT_ERR_FILE_STATUS ||
1094                             (err->code == GOT_ERR_ERRNO && errno == ENOENT))
1095                                 err = report_progress(&pa, p.old, p.new,
1096                                     GOT_STATUS_CANNOT_UPDATE, err);
1097                         else if (err->code == GOT_ERR_HUNK_FAILED)
1098                                 err = report_progress(&pa, p.old, p.new,
1099                                     GOT_STATUS_CANNOT_UPDATE, NULL);
1100                 }
1101                 if (overlapcnt != 0)
1102                         failed = 1;
1103
1104                 free(oldpath);
1105                 free(newpath);
1106                 patch_free(&p);
1107
1108                 if (err)
1109                         break;
1110         }
1111
1112 done:
1113         if (fileindex != NULL)
1114                 complete_err = got_worktree_patch_complete(fileindex,
1115                     fileindex_path);
1116         if (complete_err && err == NULL)
1117                 err = complete_err;
1118         free(fileindex_path);
1119         if (tree)
1120                 got_object_tree_close(tree);
1121         if (commit)
1122                 got_object_commit_close(commit);
1123         if (fd != -1 && close(fd) == -1 && err == NULL)
1124                 err = got_error_from_errno("close");
1125         if (ibuf != NULL)
1126                 imsg_clear(ibuf);
1127         if (imsg_fds[0] != -1 && close(imsg_fds[0]) == -1 && err == NULL)
1128                 err = got_error_from_errno("close");
1129         if (imsg_fds[1] != -1 && close(imsg_fds[1]) == -1 && err == NULL)
1130                 err = got_error_from_errno("close");
1131         if (err == NULL && failed)
1132                 err = got_error(GOT_ERR_PATCH_FAILED);
1133         return err;
1134 }