diff.c

   1 /*
   2  * Copyright (C) 2005 Junio C Hamano
   3  */
   4 #include <sys/types.h>
   5 #include <sys/wait.h>
   6 #include <signal.h>
   7 #include <limits.h>
   8 #include "cache.h"
   9 #include "diff.h"
  10 #include "diffcore.h"
  11
  12 static const char *diff_opts = "-pu";
  13 static unsigned char null_sha1[20] = { 0, };
  14
  15 static int reverse_diff;
  16 static int generate_patch;
  17 static int line_termination = '\n';
  18 static int inter_name_termination = '\t';
  19
  20 static const char *external_diff(void)
  21 {
  22         static const char *external_diff_cmd = NULL;
  23         static int done_preparing = 0;
  24
  25         if (done_preparing)
  26                 return external_diff_cmd;
  27
  28         /*
  29          * Default values above are meant to match the
  30          * Linux kernel development style.  Examples of
  31          * alternative styles you can specify via environment
  32          * variables are:
  33          *
  34          * GIT_DIFF_OPTS="-c";
  35          */
  36         if (gitenv("GIT_EXTERNAL_DIFF"))
  37                 external_diff_cmd = gitenv("GIT_EXTERNAL_DIFF");
  38
  39         /* In case external diff fails... */
  40         diff_opts = gitenv("GIT_DIFF_OPTS") ? : diff_opts;
  41
  42         done_preparing = 1;
  43         return external_diff_cmd;
  44 }
  45
  46 /* Help to copy the thing properly quoted for the shell safety.
  47  * any single quote is replaced with '\'', and the caller is
  48  * expected to enclose the result within a single quote pair.
  49  *
  50  * E.g.
  51  *  original     sq_expand     result
  52  *  name     ==> name      ==> 'name'
  53  *  a b      ==> a b       ==> 'a b'
  54  *  a'b      ==> a'\''b    ==> 'a'\''b'
  55  */
  56 static char *sq_expand(const char *src)
  57 {
  58         static char *buf = NULL;
  59         int cnt, c;
  60         const char *cp;
  61         char *bp;
  62
  63         /* count bytes needed to store the quoted string. */
  64         for (cnt = 1, cp = src; *cp; cnt++, cp++)
  65                 if (*cp == '\'')
  66                         cnt += 3;
  67
  68         buf = xmalloc(cnt);
  69         bp = buf;
  70         while ((c = *src++)) {
  71                 if (c != '\'')
  72                         *bp++ = c;
  73                 else {
  74                         bp = strcpy(bp, "'\\''");
  75                         bp += 4;
  76                 }
  77         }
  78         *bp = 0;
  79         return buf;
  80 }
  81
  82 static struct diff_tempfile {
  83         const char *name; /* filename external diff should read from */
  84         char hex[41];
  85         char mode[10];
  86         char tmp_path[50];
  87 } diff_temp[2];
  88
  89 static void builtin_diff(const char *name_a,
  90                          const char *name_b,
  91                          struct diff_tempfile *temp,
  92                          const char *xfrm_msg)
  93 {
  94         int i, next_at, cmd_size;
  95         const char *diff_cmd = "diff -L'%s%s' -L'%s%s'";
  96         const char *diff_arg  = "'%s' '%s'||:"; /* "||:" is to return 0 */
  97         const char *input_name_sq[2];
  98         const char *path0[2];
  99         const char *path1[2];
 100         const char *name_sq[2];
 101         char *cmd;
 102
 103         name_sq[0] = sq_expand(name_a);
 104         name_sq[1] = sq_expand(name_b);
 105
 106         /* diff_cmd and diff_arg have 6 %s in total which makes
 107          * the sum of these strings 12 bytes larger than required.
 108          * we use 2 spaces around diff-opts, and we need to count
 109          * terminating NUL, so we subtract 9 here.
 110          */
 111         cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
 112                         strlen(diff_arg) - 9);
 113         for (i = 0; i < 2; i++) {
 114                 input_name_sq[i] = sq_expand(temp[i].name);
 115                 if (!strcmp(temp[i].name, "/dev/null")) {
 116                         path0[i] = "/dev/null";
 117                         path1[i] = "";
 118                 } else {
 119                         path0[i] = i ? "b/" : "a/";
 120                         path1[i] = name_sq[i];
 121                 }
 122                 cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
 123                              strlen(input_name_sq[i]));
 124         }
 125
 126         cmd = xmalloc(cmd_size);
 127
 128         next_at = 0;
 129         next_at += snprintf(cmd+next_at, cmd_size-next_at,
 130                             diff_cmd,
 131                             path0[0], path1[0], path0[1], path1[1]);
 132         next_at += snprintf(cmd+next_at, cmd_size-next_at,
 133                             " %s ", diff_opts);
 134         next_at += snprintf(cmd+next_at, cmd_size-next_at,
 135                             diff_arg, input_name_sq[0], input_name_sq[1]);
 136
 137         printf("diff --git a/%s b/%s\n", name_a, name_b);
 138         if (!path1[0][0])
 139                 printf("new file mode %s\n", temp[1].mode);
 140         else if (!path1[1][0])
 141                 printf("deleted file mode %s\n", temp[0].mode);
 142         else {
 143                 if (strcmp(temp[0].mode, temp[1].mode)) {
 144                         printf("old mode %s\n", temp[0].mode);
 145                         printf("new mode %s\n", temp[1].mode);
 146                 }
 147                 if (xfrm_msg && xfrm_msg[0])
 148                         fputs(xfrm_msg, stdout);
 149
 150                 if (strncmp(temp[0].mode, temp[1].mode, 3))
 151                         /* we do not run diff between different kind
 152                          * of objects.
 153                          */
 154                         exit(0);
 155         }
 156         fflush(NULL);
 157         execlp("/bin/sh","sh", "-c", cmd, NULL);
 158 }
 159
 160 struct diff_filespec *alloc_filespec(const char *path)
 161 {
 162         int namelen = strlen(path);
 163         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 164         spec->path = (char *)(spec + 1);
 165         strcpy(spec->path, path);
 166         spec->should_free = spec->should_munmap = 0;
 167         spec->xfrm_flags = 0;
 168         spec->size = 0;
 169         spec->data = 0;
 170         spec->mode = 0;
 171         memset(spec->sha1, 0, 20);
 172         return spec;
 173 }
 174
 175 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 176                    unsigned short mode)
 177 {
 178         if (mode) { /* just playing defensive */
 179                 spec->mode = mode;
 180                 memcpy(spec->sha1, sha1, 20);
 181                 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 182         }
 183 }
 184
 185 /*
 186  * Given a name and sha1 pair, if the dircache tells us the file in
 187  * the work tree has that object contents, return true, so that
 188  * prepare_temp_file() does not have to inflate and extract.
 189  */
 190 static int work_tree_matches(const char *name, const unsigned char *sha1)
 191 {
 192         struct cache_entry *ce;
 193         struct stat st;
 194         int pos, len;
 195
 196         /* We do not read the cache ourselves here, because the
 197          * benchmark with my previous version that always reads cache
 198          * shows that it makes things worse for diff-tree comparing
 199          * two linux-2.6 kernel trees in an already checked out work
 200          * tree.  This is because most diff-tree comparisons deal with
 201          * only a small number of files, while reading the cache is
 202          * expensive for a large project, and its cost outweighs the
 203          * savings we get by not inflating the object to a temporary
 204          * file.  Practically, this code only helps when we are used
 205          * by diff-cache --cached, which does read the cache before
 206          * calling us.
 207          */
 208         if (!active_cache)
 209                 return 0;
 210
 211         len = strlen(name);
 212         pos = cache_name_pos(name, len);
 213         if (pos < 0)
 214                 return 0;
 215         ce = active_cache[pos];
 216         if ((lstat(name, &st) < 0) ||
 217             !S_ISREG(st.st_mode) || /* careful! */
 218             ce_match_stat(ce, &st) ||
 219             memcmp(sha1, ce->sha1, 20))
 220                 return 0;
 221         /* we return 1 only when we can stat, it is a regular file,
 222          * stat information matches, and sha1 recorded in the cache
 223          * matches.  I.e. we know the file in the work tree really is
 224          * the same as the <name, sha1> pair.
 225          */
 226         return 1;
 227 }
 228
 229 /*
 230  * While doing rename detection and pickaxe operation, we may need to
 231  * grab the data for the blob (or file) for our own in-core comparison.
 232  * diff_filespec has data and size fields for this purpose.
 233  */
 234 int diff_populate_filespec(struct diff_filespec *s)
 235 {
 236         int err = 0;
 237         if (!DIFF_FILE_VALID(s))
 238                 die("internal error: asking to populate invalid file.");
 239         if (S_ISDIR(s->mode))
 240                 return -1;
 241
 242         if (s->data)
 243                 return err;
 244         if (!s->sha1_valid ||
 245             work_tree_matches(s->path, s->sha1)) {
 246                 struct stat st;
 247                 int fd;
 248                 if (lstat(s->path, &st) < 0) {
 249                         if (errno == ENOENT) {
 250                         err_empty:
 251                                 err = -1;
 252                         empty:
 253                                 s->data = "";
 254                                 s->size = 0;
 255                                 return err;
 256                         }
 257                 }
 258                 s->size = st.st_size;
 259                 if (!s->size)
 260                         goto empty;
 261                 if (S_ISLNK(st.st_mode)) {
 262                         int ret;
 263                         s->data = xmalloc(s->size);
 264                         s->should_free = 1;
 265                         ret = readlink(s->path, s->data, s->size);
 266                         if (ret < 0) {
 267                                 free(s->data);
 268                                 goto err_empty;
 269                         }
 270                         return 0;
 271                 }
 272                 fd = open(s->path, O_RDONLY);
 273                 if (fd < 0)
 274                         goto err_empty;
 275                 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 276                 s->should_munmap = 1;
 277                 close(fd);
 278         }
 279         else {
 280                 char type[20];
 281                 s->data = read_sha1_file(s->sha1, type, &s->size);
 282                 s->should_free = 1;
 283         }
 284         return 0;
 285 }
 286
 287 void diff_free_filepair(struct diff_filepair *p)
 288 {
 289         free(p->xfrm_msg);
 290         free(p);
 291 }
 292
 293 void diff_free_filespec_data(struct diff_filespec *s)
 294 {
 295         if (s->should_free)
 296                 free(s->data);
 297         else if (s->should_munmap)
 298                 munmap(s->data, s->size);
 299         s->should_free = s->should_munmap = 0;
 300         s->data = 0;
 301 }
 302
 303 static void prep_temp_blob(struct diff_tempfile *temp,
 304                            void *blob,
 305                            unsigned long size,
 306                            unsigned char *sha1,
 307                            int mode)
 308 {
 309         int fd;
 310
 311         strcpy(temp->tmp_path, ".diff_XXXXXX");
 312         fd = mkstemp(temp->tmp_path);
 313         if (fd < 0)
 314                 die("unable to create temp-file");
 315         if (write(fd, blob, size) != size)
 316                 die("unable to write temp-file");
 317         close(fd);
 318         temp->name = temp->tmp_path;
 319         strcpy(temp->hex, sha1_to_hex(sha1));
 320         temp->hex[40] = 0;
 321         sprintf(temp->mode, "%06o", mode);
 322 }
 323
 324 static void prepare_temp_file(const char *name,
 325                               struct diff_tempfile *temp,
 326                               struct diff_filespec *one)
 327 {
 328         if (!DIFF_FILE_VALID(one)) {
 329         not_a_valid_file:
 330                 /* A '-' entry produces this for file-2, and
 331                  * a '+' entry produces this for file-1.
 332                  */
 333                 temp->name = "/dev/null";
 334                 strcpy(temp->hex, ".");
 335                 strcpy(temp->mode, ".");
 336                 return;
 337         }
 338
 339         if (!one->sha1_valid ||
 340             work_tree_matches(name, one->sha1)) {
 341                 struct stat st;
 342                 if (lstat(name, &st) < 0) {
 343                         if (errno == ENOENT)
 344                                 goto not_a_valid_file;
 345                         die("stat(%s): %s", name, strerror(errno));
 346                 }
 347                 if (S_ISLNK(st.st_mode)) {
 348                         int ret;
 349                         char *buf, buf_[1024];
 350                         buf = ((sizeof(buf_) < st.st_size) ?
 351                                xmalloc(st.st_size) : buf_);
 352                         ret = readlink(name, buf, st.st_size);
 353                         if (ret < 0)
 354                                 die("readlink(%s)", name);
 355                         prep_temp_blob(temp, buf, st.st_size,
 356                                        (one->sha1_valid ?
 357                                         one->sha1 : null_sha1),
 358                                        (one->sha1_valid ?
 359                                         one->mode : S_IFLNK));
 360                 }
 361                 else {
 362                         /* we can borrow from the file in the work tree */
 363                         temp->name = name;
 364                         if (!one->sha1_valid)
 365                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
 366                         else
 367                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
 368                         sprintf(temp->mode, "%06o",
 369                                 S_IFREG |ce_permissions(st.st_mode));
 370                 }
 371                 return;
 372         }
 373         else {
 374                 if (diff_populate_filespec(one))
 375                         die("cannot read data blob for %s", one->path);
 376                 prep_temp_blob(temp, one->data, one->size,
 377                                one->sha1, one->mode);
 378         }
 379 }
 380
 381 static void remove_tempfile(void)
 382 {
 383         int i;
 384
 385         for (i = 0; i < 2; i++)
 386                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
 387                         unlink(diff_temp[i].name);
 388                         diff_temp[i].name = NULL;
 389                 }
 390 }
 391
 392 static void remove_tempfile_on_signal(int signo)
 393 {
 394         remove_tempfile();
 395 }
 396
 397 /* An external diff command takes:
 398  *
 399  * diff-cmd name infile1 infile1-sha1 infile1-mode \
 400  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
 401  *
 402  */
 403 static void run_external_diff(const char *name,
 404                               const char *other,
 405                               struct diff_filespec *one,
 406                               struct diff_filespec *two,
 407                               const char *xfrm_msg)
 408 {
 409         struct diff_tempfile *temp = diff_temp;
 410         pid_t pid;
 411         int status;
 412         static int atexit_asked = 0;
 413
 414         if (one && two) {
 415                 prepare_temp_file(name, &temp[0], one);
 416                 prepare_temp_file(other ? : name, &temp[1], two);
 417                 if (! atexit_asked &&
 418                     (temp[0].name == temp[0].tmp_path ||
 419                      temp[1].name == temp[1].tmp_path)) {
 420                         atexit_asked = 1;
 421                         atexit(remove_tempfile);
 422                 }
 423                 signal(SIGINT, remove_tempfile_on_signal);
 424         }
 425
 426         fflush(NULL);
 427         pid = fork();
 428         if (pid < 0)
 429                 die("unable to fork");
 430         if (!pid) {
 431                 const char *pgm = external_diff();
 432                 if (pgm) {
 433                         if (one && two) {
 434                                 const char *exec_arg[10];
 435                                 const char **arg = &exec_arg[0];
 436                                 *arg++ = pgm;
 437                                 *arg++ = name;
 438                                 *arg++ = temp[0].name;
 439                                 *arg++ = temp[0].hex;
 440                                 *arg++ = temp[0].mode;
 441                                 *arg++ = temp[1].name;
 442                                 *arg++ = temp[1].hex;
 443                                 *arg++ = temp[1].mode;
 444                                 if (other) {
 445                                         *arg++ = other;
 446                                         *arg++ = xfrm_msg;
 447                                 }
 448                                 *arg = 0;
 449                                 execvp(pgm, (char *const*) exec_arg);
 450                         }
 451                         else
 452                                 execlp(pgm, pgm, name, NULL);
 453                 }
 454                 /*
 455                  * otherwise we use the built-in one.
 456                  */
 457                 if (one && two)
 458                         builtin_diff(name, other ? : name, temp, xfrm_msg);
 459                 else
 460                         printf("* Unmerged path %s\n", name);
 461                 exit(0);
 462         }
 463         if (waitpid(pid, &status, 0) < 0 ||
 464             !WIFEXITED(status) || WEXITSTATUS(status)) {
 465                 /* Earlier we did not check the exit status because
 466                  * diff exits non-zero if files are different, and
 467                  * we are not interested in knowing that.  It was a
 468                  * mistake which made it harder to quit a diff-*
 469                  * session that uses the git-apply-patch-script as
 470                  * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
 471                  * should also exit non-zero only when it wants to
 472                  * abort the entire diff-* session.
 473                  */
 474                 remove_tempfile();
 475                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
 476                 exit(1);
 477         }
 478         remove_tempfile();
 479 }
 480
 481 void diff_setup(int reverse_diff_)
 482 {
 483         reverse_diff = reverse_diff_;
 484 }
 485
 486 struct diff_queue_struct diff_queued_diff;
 487
 488 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
 489 {
 490         if (queue->alloc <= queue->nr) {
 491                 queue->alloc = alloc_nr(queue->alloc);
 492                 queue->queue = xrealloc(queue->queue,
 493                                         sizeof(dp) * queue->alloc);
 494         }
 495         queue->queue[queue->nr++] = dp;
 496 }
 497
 498 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
 499                                  struct diff_filespec *one,
 500                                  struct diff_filespec *two)
 501 {
 502         struct diff_filepair *dp = xmalloc(sizeof(*dp));
 503         dp->one = one;
 504         dp->two = two;
 505         dp->xfrm_msg = 0;
 506         dp->orig_order = queue->nr;
 507         dp->xfrm_work = 0;
 508         diff_q(queue, dp);
 509         return dp;
 510 }
 511
 512 static void diff_flush_raw(struct diff_filepair *p)
 513 {
 514         if (DIFF_PAIR_UNMERGED(p)) {
 515                 printf("U %s%c", p->one->path, line_termination);
 516                 return;
 517         }
 518         printf(":%06o %06o %s ",
 519                p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
 520         printf("%s%c%s%c%s%c",
 521                sha1_to_hex(p->two->sha1), inter_name_termination,
 522                p->one->path, inter_name_termination,
 523                p->two->path, line_termination);
 524 }
 525
 526 static void diff_flush_patch(struct diff_filepair *p)
 527 {
 528         const char *name, *other;
 529
 530         name = p->one->path;
 531         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
 532         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
 533             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
 534                 return; /* no tree diffs in patch format */
 535
 536         if (DIFF_PAIR_UNMERGED(p))
 537                 run_external_diff(name, NULL, NULL, NULL, NULL);
 538         else
 539                 run_external_diff(name, other, p->one, p->two, p->xfrm_msg);
 540 }
 541
 542 static int uninteresting(struct diff_filepair *p)
 543 {
 544         /* This function is written stricter than necessary to support
 545          * the currently implemented transformers, but the idea is to
 546          * let transformers to produce diff_filepairs any way they want,
 547          * and filter and clean them up here before producing the output.
 548          */
 549         struct diff_filespec *one, *two;
 550
 551         if (DIFF_PAIR_UNMERGED(p))
 552                 return 0; /* unmerged is interesting */
 553
 554         one = p->one;
 555         two = p->two;
 556
 557         /* deletion, addition, mode change and renames are all interesting. */
 558         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
 559             (one->mode != two->mode) ||
 560             strcmp(one->path, two->path))
 561                 return 0;
 562
 563         /* both are valid and point at the same path.  that is, we are
 564          * dealing with a change.
 565          */
 566         if (one->sha1_valid && two->sha1_valid &&
 567             !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
 568                 return 1; /* no change */
 569         if (!one->sha1_valid && !two->sha1_valid)
 570                 return 1; /* both look at the same file on the filesystem. */
 571         return 0;
 572 }
 573
 574 void diffcore_prune(void)
 575 {
 576         /*
 577          * Although rename/copy detection wants to have "no-change"
 578          * entries fed into them, the downstream do not need to see
 579          * them.  This function removes such entries.
 580          *
 581          * The applications that use rename/copy should:
 582          *
 583          * (1) feed change and "no-change" entries via diff_queue().
 584          * (2) call diffcore_rename, and any other future diffcore_xxx
 585          *     that would benefit by still having "no-change" entries.
 586          * (3) call diffcore_prune
 587          * (4) call other diffcore_xxx that do not need to see
 588          *     "no-change" entries.
 589          */
 590         struct diff_queue_struct *q = &diff_queued_diff;
 591         struct diff_queue_struct outq;
 592         int i;
 593
 594         outq.queue = NULL;
 595         outq.nr = outq.alloc = 0;
 596
 597         for (i = 0; i < q->nr; i++) {
 598                 struct diff_filepair *p = q->queue[i];
 599                 if (!uninteresting(p))
 600                         diff_q(&outq, p);
 601                 else
 602                         diff_free_filepair(p);
 603         }
 604         free(q->queue);
 605         *q = outq;
 606         return;
 607 }
 608
 609 static void diff_flush_one(struct diff_filepair *p)
 610 {
 611         if (uninteresting(p))
 612                 return;
 613         if (generate_patch)
 614                 diff_flush_patch(p);
 615         else
 616                 diff_flush_raw(p);
 617 }
 618
 619 int diff_queue_is_empty(void)
 620 {
 621         struct diff_queue_struct *q = &diff_queued_diff;
 622         int i;
 623
 624         for (i = 0; i < q->nr; i++) {
 625                 struct diff_filepair *p = q->queue[i];
 626                 if (!uninteresting(p))
 627                         return 0;
 628         }
 629         return 1;
 630 }
 631
 632 void diff_flush(int diff_output_style)
 633 {
 634         struct diff_queue_struct *q = &diff_queued_diff;
 635         int i;
 636
 637         generate_patch = 0;
 638         switch (diff_output_style) {
 639         case DIFF_FORMAT_HUMAN:
 640                 line_termination = '\n';
 641                 inter_name_termination = '\t';
 642                 break;
 643         case DIFF_FORMAT_MACHINE:
 644                 line_termination = inter_name_termination = 0;
 645                 break;
 646         case DIFF_FORMAT_PATCH:
 647                 generate_patch = 1;
 648                 break;
 649         }
 650         for (i = 0; i < q->nr; i++)
 651                 diff_flush_one(q->queue[i]);
 652         for (i = 0; i < q->nr; i++) {
 653                 struct diff_filepair *p = q->queue[i];
 654                 diff_free_filespec_data(p->one);
 655                 diff_free_filespec_data(p->two);
 656                 free(p->xfrm_msg);
 657                 free(p);
 658         }
 659         free(q->queue);
 660         q->queue = NULL;
 661         q->nr = q->alloc = 0;
 662 }
 663
 664 void diff_addremove(int addremove, unsigned mode,
 665                     const unsigned char *sha1,
 666                     const char *base, const char *path)
 667 {
 668         char concatpath[PATH_MAX];
 669         struct diff_filespec *one, *two;
 670
 671         /* This may look odd, but it is a preparation for
 672          * feeding "there are unchanged files which should
 673          * not produce diffs, but when you are doing copy
 674          * detection you would need them, so here they are"
 675          * entries to the diff-core.  They will be prefixed
 676          * with something like '=' or '*' (I haven't decided
 677          * which but should not make any difference).
 678          * Feeding the same new and old to diff_change() should
 679          * also have the same effect.  diff_flush() should
 680          * filter uninteresting ones out at the final output
 681          * stage.
 682          */
 683         if (reverse_diff)
 684                 addremove = (addremove == '+' ? '-' :
 685                              addremove == '-' ? '+' : addremove);
 686
 687         if (!path) path = "";
 688         sprintf(concatpath, "%s%s", base, path);
 689         one = alloc_filespec(concatpath);
 690         two = alloc_filespec(concatpath);
 691
 692         if (addremove != '+')
 693                 fill_filespec(one, sha1, mode);
 694         if (addremove != '-')
 695                 fill_filespec(two, sha1, mode);
 696
 697         diff_queue(&diff_queued_diff, one, two);
 698 }
 699
 700 void diff_guif(unsigned old_mode,
 701                unsigned new_mode,
 702                const unsigned char *old_sha1,
 703                const unsigned char *new_sha1,
 704                const char *old_path,
 705                const char *new_path)
 706 {
 707         struct diff_filespec *one, *two;
 708
 709         if (reverse_diff) {
 710                 unsigned tmp;
 711                 const unsigned char *tmp_c;
 712                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
 713                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
 714         }
 715         one = alloc_filespec(old_path);
 716         two = alloc_filespec(new_path);
 717         if (old_mode)
 718                 fill_filespec(one, old_sha1, old_mode);
 719         if (new_mode)
 720                 fill_filespec(two, new_sha1, new_mode);
 721         diff_queue(&diff_queued_diff, one, two);
 722 }
 723
 724 void diff_change(unsigned old_mode, unsigned new_mode,
 725                  const unsigned char *old_sha1,
 726                  const unsigned char *new_sha1,
 727                  const char *base, const char *path)
 728 {
 729         char concatpath[PATH_MAX];
 730         struct diff_filespec *one, *two;
 731
 732         if (reverse_diff) {
 733                 unsigned tmp;
 734                 const unsigned char *tmp_c;
 735                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
 736                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
 737         }
 738         if (!path) path = "";
 739         sprintf(concatpath, "%s%s", base, path);
 740         one = alloc_filespec(concatpath);
 741         two = alloc_filespec(concatpath);
 742         fill_filespec(one, old_sha1, old_mode);
 743         fill_filespec(two, new_sha1, new_mode);
 744
 745         diff_queue(&diff_queued_diff, one, two);
 746 }
 747
 748 void diff_unmerge(const char *path)
 749 {
 750         struct diff_filespec *one, *two;
 751         one = alloc_filespec(path);
 752         two = alloc_filespec(path);
 753         diff_queue(&diff_queued_diff, one, two);
 754 }