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 static const char **pathspec;
  20 static int speccnt;
  21
  22 static const char *external_diff(void)
  23 {
  24         static const char *external_diff_cmd = NULL;
  25         static int done_preparing = 0;
  26
  27         if (done_preparing)
  28                 return external_diff_cmd;
  29
  30         /*
  31          * Default values above are meant to match the
  32          * Linux kernel development style.  Examples of
  33          * alternative styles you can specify via environment
  34          * variables are:
  35          *
  36          * GIT_DIFF_OPTS="-c";
  37          */
  38         if (gitenv("GIT_EXTERNAL_DIFF"))
  39                 external_diff_cmd = gitenv("GIT_EXTERNAL_DIFF");
  40
  41         /* In case external diff fails... */
  42         diff_opts = gitenv("GIT_DIFF_OPTS") ? : diff_opts;
  43
  44         done_preparing = 1;
  45         return external_diff_cmd;
  46 }
  47
  48 /* Help to copy the thing properly quoted for the shell safety.
  49  * any single quote is replaced with '\'', and the caller is
  50  * expected to enclose the result within a single quote pair.
  51  *
  52  * E.g.
  53  *  original     sq_expand     result
  54  *  name     ==> name      ==> 'name'
  55  *  a b      ==> a b       ==> 'a b'
  56  *  a'b      ==> a'\''b    ==> 'a'\''b'
  57  */
  58 static char *sq_expand(const char *src)
  59 {
  60         static char *buf = NULL;
  61         int cnt, c;
  62         const char *cp;
  63         char *bp;
  64
  65         /* count bytes needed to store the quoted string. */
  66         for (cnt = 1, cp = src; *cp; cnt++, cp++)
  67                 if (*cp == '\'')
  68                         cnt += 3;
  69
  70         buf = xmalloc(cnt);
  71         bp = buf;
  72         while ((c = *src++)) {
  73                 if (c != '\'')
  74                         *bp++ = c;
  75                 else {
  76                         bp = strcpy(bp, "'\\''");
  77                         bp += 4;
  78                 }
  79         }
  80         *bp = 0;
  81         return buf;
  82 }
  83
  84 static struct diff_tempfile {
  85         const char *name; /* filename external diff should read from */
  86         char hex[41];
  87         char mode[10];
  88         char tmp_path[50];
  89 } diff_temp[2];
  90
  91 static void builtin_diff(const char *name_a,
  92                          const char *name_b,
  93                          struct diff_tempfile *temp,
  94                          const char *xfrm_msg)
  95 {
  96         int i, next_at, cmd_size;
  97         const char *diff_cmd = "diff -L'%s%s' -L'%s%s'";
  98         const char *diff_arg  = "'%s' '%s'||:"; /* "||:" is to return 0 */
  99         const char *input_name_sq[2];
 100         const char *path0[2];
 101         const char *path1[2];
 102         const char *name_sq[2];
 103         char *cmd;
 104
 105         name_sq[0] = sq_expand(name_a);
 106         name_sq[1] = sq_expand(name_b);
 107
 108         /* diff_cmd and diff_arg have 6 %s in total which makes
 109          * the sum of these strings 12 bytes larger than required.
 110          * we use 2 spaces around diff-opts, and we need to count
 111          * terminating NUL, so we subtract 9 here.
 112          */
 113         cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
 114                         strlen(diff_arg) - 9);
 115         for (i = 0; i < 2; i++) {
 116                 input_name_sq[i] = sq_expand(temp[i].name);
 117                 if (!strcmp(temp[i].name, "/dev/null")) {
 118                         path0[i] = "/dev/null";
 119                         path1[i] = "";
 120                 } else {
 121                         path0[i] = i ? "b/" : "a/";
 122                         path1[i] = name_sq[i];
 123                 }
 124                 cmd_size += (strlen(path0[i]) + strlen(path1[i]) +
 125                              strlen(input_name_sq[i]));
 126         }
 127
 128         cmd = xmalloc(cmd_size);
 129
 130         next_at = 0;
 131         next_at += snprintf(cmd+next_at, cmd_size-next_at,
 132                             diff_cmd,
 133                             path0[0], path1[0], path0[1], path1[1]);
 134         next_at += snprintf(cmd+next_at, cmd_size-next_at,
 135                             " %s ", diff_opts);
 136         next_at += snprintf(cmd+next_at, cmd_size-next_at,
 137                             diff_arg, input_name_sq[0], input_name_sq[1]);
 138
 139         printf("diff --git a/%s b/%s\n", name_a, name_b);
 140         if (!path1[0][0])
 141                 printf("new file mode %s\n", temp[1].mode);
 142         else if (!path1[1][0])
 143                 printf("deleted file mode %s\n", temp[0].mode);
 144         else {
 145                 if (strcmp(temp[0].mode, temp[1].mode)) {
 146                         printf("old mode %s\n", temp[0].mode);
 147                         printf("new mode %s\n", temp[1].mode);
 148                 }
 149                 if (xfrm_msg && xfrm_msg[0])
 150                         fputs(xfrm_msg, stdout);
 151
 152                 if (strncmp(temp[0].mode, temp[1].mode, 3))
 153                         /* we do not run diff between different kind
 154                          * of objects.
 155                          */
 156                         exit(0);
 157         }
 158         fflush(NULL);
 159         execlp("/bin/sh","sh", "-c", cmd, NULL);
 160 }
 161
 162 struct diff_filespec *alloc_filespec(const char *path)
 163 {
 164         int namelen = strlen(path);
 165         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 166         spec->path = (char *)(spec + 1);
 167         strcpy(spec->path, path);
 168         spec->should_free = spec->should_munmap = 0;
 169         spec->xfrm_flags = 0;
 170         spec->size = 0;
 171         spec->data = 0;
 172         spec->mode = 0;
 173         memset(spec->sha1, 0, 20);
 174         return spec;
 175 }
 176
 177 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 178                    unsigned short mode)
 179 {
 180         if (mode) { /* just playing defensive */
 181                 spec->mode = mode;
 182                 memcpy(spec->sha1, sha1, 20);
 183                 spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 184         }
 185 }
 186
 187 /*
 188  * Given a name and sha1 pair, if the dircache tells us the file in
 189  * the work tree has that object contents, return true, so that
 190  * prepare_temp_file() does not have to inflate and extract.
 191  */
 192 static int work_tree_matches(const char *name, const unsigned char *sha1)
 193 {
 194         struct cache_entry *ce;
 195         struct stat st;
 196         int pos, len;
 197
 198         /* We do not read the cache ourselves here, because the
 199          * benchmark with my previous version that always reads cache
 200          * shows that it makes things worse for diff-tree comparing
 201          * two linux-2.6 kernel trees in an already checked out work
 202          * tree.  This is because most diff-tree comparisons deal with
 203          * only a small number of files, while reading the cache is
 204          * expensive for a large project, and its cost outweighs the
 205          * savings we get by not inflating the object to a temporary
 206          * file.  Practically, this code only helps when we are used
 207          * by diff-cache --cached, which does read the cache before
 208          * calling us.
 209          */
 210         if (!active_cache)
 211                 return 0;
 212
 213         len = strlen(name);
 214         pos = cache_name_pos(name, len);
 215         if (pos < 0)
 216                 return 0;
 217         ce = active_cache[pos];
 218         if ((lstat(name, &st) < 0) ||
 219             !S_ISREG(st.st_mode) || /* careful! */
 220             ce_match_stat(ce, &st) ||
 221             memcmp(sha1, ce->sha1, 20))
 222                 return 0;
 223         /* we return 1 only when we can stat, it is a regular file,
 224          * stat information matches, and sha1 recorded in the cache
 225          * matches.  I.e. we know the file in the work tree really is
 226          * the same as the <name, sha1> pair.
 227          */
 228         return 1;
 229 }
 230
 231 /*
 232  * While doing rename detection and pickaxe operation, we may need to
 233  * grab the data for the blob (or file) for our own in-core comparison.
 234  * diff_filespec has data and size fields for this purpose.
 235  */
 236 int diff_populate_filespec(struct diff_filespec *s)
 237 {
 238         int err = 0;
 239         if (!DIFF_FILE_VALID(s))
 240                 die("internal error: asking to populate invalid file.");
 241         if (S_ISDIR(s->mode))
 242                 return -1;
 243
 244         if (s->data)
 245                 return err;
 246         if (!s->sha1_valid ||
 247             work_tree_matches(s->path, s->sha1)) {
 248                 struct stat st;
 249                 int fd;
 250                 if (lstat(s->path, &st) < 0) {
 251                         if (errno == ENOENT) {
 252                         err_empty:
 253                                 err = -1;
 254                         empty:
 255                                 s->data = "";
 256                                 s->size = 0;
 257                                 return err;
 258                         }
 259                 }
 260                 s->size = st.st_size;
 261                 if (!s->size)
 262                         goto empty;
 263                 if (S_ISLNK(st.st_mode)) {
 264                         int ret;
 265                         s->data = xmalloc(s->size);
 266                         s->should_free = 1;
 267                         ret = readlink(s->path, s->data, s->size);
 268                         if (ret < 0) {
 269                                 free(s->data);
 270                                 goto err_empty;
 271                         }
 272                         return 0;
 273                 }
 274                 fd = open(s->path, O_RDONLY);
 275                 if (fd < 0)
 276                         goto err_empty;
 277                 s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 278                 s->should_munmap = 1;
 279                 close(fd);
 280         }
 281         else {
 282                 char type[20];
 283                 s->data = read_sha1_file(s->sha1, type, &s->size);
 284                 s->should_free = 1;
 285         }
 286         return 0;
 287 }
 288
 289 void diff_free_filespec_data(struct diff_filespec *s)
 290 {
 291         if (s->should_free)
 292                 free(s->data);
 293         else if (s->should_munmap)
 294                 munmap(s->data, s->size);
 295         s->should_free = s->should_munmap = 0;
 296         s->data = 0;
 297 }
 298
 299 static void prep_temp_blob(struct diff_tempfile *temp,
 300                            void *blob,
 301                            unsigned long size,
 302                            unsigned char *sha1,
 303                            int mode)
 304 {
 305         int fd;
 306
 307         strcpy(temp->tmp_path, ".diff_XXXXXX");
 308         fd = mkstemp(temp->tmp_path);
 309         if (fd < 0)
 310                 die("unable to create temp-file");
 311         if (write(fd, blob, size) != size)
 312                 die("unable to write temp-file");
 313         close(fd);
 314         temp->name = temp->tmp_path;
 315         strcpy(temp->hex, sha1_to_hex(sha1));
 316         temp->hex[40] = 0;
 317         sprintf(temp->mode, "%06o", mode);
 318 }
 319
 320 static void prepare_temp_file(const char *name,
 321                               struct diff_tempfile *temp,
 322                               struct diff_filespec *one)
 323 {
 324         if (!DIFF_FILE_VALID(one)) {
 325         not_a_valid_file:
 326                 /* A '-' entry produces this for file-2, and
 327                  * a '+' entry produces this for file-1.
 328                  */
 329                 temp->name = "/dev/null";
 330                 strcpy(temp->hex, ".");
 331                 strcpy(temp->mode, ".");
 332                 return;
 333         }
 334
 335         if (!one->sha1_valid ||
 336             work_tree_matches(name, one->sha1)) {
 337                 struct stat st;
 338                 if (lstat(name, &st) < 0) {
 339                         if (errno == ENOENT)
 340                                 goto not_a_valid_file;
 341                         die("stat(%s): %s", name, strerror(errno));
 342                 }
 343                 if (S_ISLNK(st.st_mode)) {
 344                         int ret;
 345                         char *buf, buf_[1024];
 346                         buf = ((sizeof(buf_) < st.st_size) ?
 347                                xmalloc(st.st_size) : buf_);
 348                         ret = readlink(name, buf, st.st_size);
 349                         if (ret < 0)
 350                                 die("readlink(%s)", name);
 351                         prep_temp_blob(temp, buf, st.st_size,
 352                                        (one->sha1_valid ?
 353                                         one->sha1 : null_sha1),
 354                                        (one->sha1_valid ?
 355                                         one->mode : S_IFLNK));
 356                 }
 357                 else {
 358                         /* we can borrow from the file in the work tree */
 359                         temp->name = name;
 360                         if (!one->sha1_valid)
 361                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
 362                         else
 363                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
 364                         sprintf(temp->mode, "%06o",
 365                                 S_IFREG |ce_permissions(st.st_mode));
 366                 }
 367                 return;
 368         }
 369         else {
 370                 if (diff_populate_filespec(one))
 371                         die("cannot read data blob for %s", one->path);
 372                 prep_temp_blob(temp, one->data, one->size,
 373                                one->sha1, one->mode);
 374         }
 375 }
 376
 377 static void remove_tempfile(void)
 378 {
 379         int i;
 380
 381         for (i = 0; i < 2; i++)
 382                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
 383                         unlink(diff_temp[i].name);
 384                         diff_temp[i].name = NULL;
 385                 }
 386 }
 387
 388 static void remove_tempfile_on_signal(int signo)
 389 {
 390         remove_tempfile();
 391 }
 392
 393 static int matches_pathspec(const char *name)
 394 {
 395         int i;
 396         int namelen;
 397
 398         if (speccnt == 0)
 399                 return 1;
 400
 401         namelen = strlen(name);
 402         for (i = 0; i < speccnt; i++) {
 403                 int speclen = strlen(pathspec[i]);
 404                 if (! strncmp(pathspec[i], name, speclen) &&
 405                     speclen <= namelen &&
 406                     (name[speclen] == 0 || name[speclen] == '/'))
 407                         return 1;
 408         }
 409         return 0;
 410 }
 411
 412 /* An external diff command takes:
 413  *
 414  * diff-cmd name infile1 infile1-sha1 infile1-mode \
 415  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
 416  *
 417  */
 418 static void run_external_diff(const char *name,
 419                               const char *other,
 420                               struct diff_filespec *one,
 421                               struct diff_filespec *two,
 422                               const char *xfrm_msg)
 423 {
 424         struct diff_tempfile *temp = diff_temp;
 425         pid_t pid;
 426         int status;
 427         static int atexit_asked = 0;
 428
 429         if (!matches_pathspec(name) && (!other || !matches_pathspec(other)))
 430                 return;
 431
 432         if (one && two) {
 433                 prepare_temp_file(name, &temp[0], one);
 434                 prepare_temp_file(other ? : name, &temp[1], two);
 435                 if (! atexit_asked &&
 436                     (temp[0].name == temp[0].tmp_path ||
 437                      temp[1].name == temp[1].tmp_path)) {
 438                         atexit_asked = 1;
 439                         atexit(remove_tempfile);
 440                 }
 441                 signal(SIGINT, remove_tempfile_on_signal);
 442         }
 443
 444         fflush(NULL);
 445         pid = fork();
 446         if (pid < 0)
 447                 die("unable to fork");
 448         if (!pid) {
 449                 const char *pgm = external_diff();
 450                 if (pgm) {
 451                         if (one && two) {
 452                                 const char *exec_arg[10];
 453                                 const char **arg = &exec_arg[0];
 454                                 *arg++ = pgm;
 455                                 *arg++ = name;
 456                                 *arg++ = temp[0].name;
 457                                 *arg++ = temp[0].hex;
 458                                 *arg++ = temp[0].mode;
 459                                 *arg++ = temp[1].name;
 460                                 *arg++ = temp[1].hex;
 461                                 *arg++ = temp[1].mode;
 462                                 if (other) {
 463                                         *arg++ = other;
 464                                         *arg++ = xfrm_msg;
 465                                 }
 466                                 *arg = 0;
 467                                 execvp(pgm, (char *const*) exec_arg);
 468                         }
 469                         else
 470                                 execlp(pgm, pgm, name, NULL);
 471                 }
 472                 /*
 473                  * otherwise we use the built-in one.
 474                  */
 475                 if (one && two)
 476                         builtin_diff(name, other ? : name, temp, xfrm_msg);
 477                 else
 478                         printf("* Unmerged path %s\n", name);
 479                 exit(0);
 480         }
 481         if (waitpid(pid, &status, 0) < 0 ||
 482             !WIFEXITED(status) || WEXITSTATUS(status)) {
 483                 /* Earlier we did not check the exit status because
 484                  * diff exits non-zero if files are different, and
 485                  * we are not interested in knowing that.  It was a
 486                  * mistake which made it harder to quit a diff-*
 487                  * session that uses the git-apply-patch-script as
 488                  * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
 489                  * should also exit non-zero only when it wants to
 490                  * abort the entire diff-* session.
 491                  */
 492                 remove_tempfile();
 493                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
 494                 exit(1);
 495         }
 496         remove_tempfile();
 497 }
 498
 499 int diff_scoreopt_parse(const char *opt)
 500 {
 501         int diglen, num, scale, i;
 502         if (opt[0] != '-' || (opt[1] != 'M' && opt[1] != 'C'))
 503                 return -1; /* that is not a -M nor -C option */
 504         diglen = strspn(opt+2, "0123456789");
 505         if (diglen == 0 || strlen(opt+2) != diglen)
 506                 return 0; /* use default */
 507         sscanf(opt+2, "%d", &num);
 508         for (i = 0, scale = 1; i < diglen; i++)
 509                 scale *= 10;
 510
 511         /* user says num divided by scale and we say internally that
 512          * is MAX_SCORE * num / scale.
 513          */
 514         return MAX_SCORE * num / scale;
 515 }
 516
 517 void diff_setup(int reverse_diff_, int diff_output_style)
 518 {
 519         reverse_diff = reverse_diff_;
 520         generate_patch = 0;
 521         switch (diff_output_style) {
 522         case DIFF_FORMAT_HUMAN:
 523                 line_termination = '\n';
 524                 inter_name_termination = '\t';
 525                 break;
 526         case DIFF_FORMAT_MACHINE:
 527                 line_termination = inter_name_termination = 0;
 528                 break;
 529         case DIFF_FORMAT_PATCH:
 530                 generate_patch = 1;
 531                 break;
 532         }
 533 }
 534
 535 struct diff_queue_struct diff_queued_diff;
 536
 537 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
 538                                   struct diff_filespec *one,
 539                                   struct diff_filespec *two)
 540 {
 541         struct diff_filepair *dp = xmalloc(sizeof(*dp));
 542         dp->one = one;
 543         dp->two = two;
 544         dp->xfrm_msg = 0;
 545         dp->orig_order = queue->nr;
 546         dp->xfrm_work = 0;
 547         if (queue->alloc <= queue->nr) {
 548                 queue->alloc = alloc_nr(queue->alloc);
 549                 queue->queue = xrealloc(queue->queue,
 550                                        sizeof(dp) * queue->alloc);
 551         }
 552         queue->queue[queue->nr++] = dp;
 553         return dp;
 554 }
 555
 556 static void diff_flush_raw(struct diff_filepair *p)
 557 {
 558         /*
 559          * We used to reject rename/copy but new diff-raw can express them.
 560          */
 561         printf(":%06o %06o %s ",
 562                p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
 563         printf("%s%c%s%c%s%c",
 564                sha1_to_hex(p->two->sha1), inter_name_termination,
 565                p->one->path, inter_name_termination,
 566                p->two->path, line_termination);
 567 }
 568
 569 static void diff_flush_patch(struct diff_filepair *p)
 570 {
 571         const char *name, *other;
 572
 573         name = p->one->path;
 574         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
 575         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
 576             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
 577                 return; /* no tree diffs in patch format */
 578
 579         run_external_diff(name, other, p->one, p->two, p->xfrm_msg);
 580 }
 581
 582 static int identical(struct diff_filespec *one, struct diff_filespec *two)
 583 {
 584         /* This function is written stricter than necessary to support
 585          * the currently implemented transformers, but the idea is to
 586          * let transformers to produce diff_filepairs any way they want,
 587          * and filter and clean them up here before producing the output.
 588          */
 589
 590         if (!DIFF_FILE_VALID(one) && !DIFF_FILE_VALID(two))
 591                 return 1; /* not interesting */
 592
 593         /* deletion, addition, mode change and renames are all interesting. */
 594         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
 595             (one->mode != two->mode) ||
 596             strcmp(one->path, two->path))
 597                 return 0;
 598
 599         /* both are valid and point at the same path.  that is, we are
 600          * dealing with a change.
 601          */
 602         if (one->sha1_valid && two->sha1_valid &&
 603             !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
 604                 return 1; /* no change */
 605         if (!one->sha1_valid && !two->sha1_valid)
 606                 return 1; /* both look at the same file on the filesystem. */
 607         return 0;
 608 }
 609
 610 static void diff_flush_one(struct diff_filepair *p)
 611 {
 612         if (identical(p->one, p->two))
 613                 return;
 614         if (generate_patch)
 615                 diff_flush_patch(p);
 616         else
 617                 diff_flush_raw(p);
 618 }
 619
 620 int diff_queue_is_empty(void)
 621 {
 622         struct diff_queue_struct *q = &diff_queued_diff;
 623         int i;
 624
 625         for (i = 0; i < q->nr; i++) {
 626                 struct diff_filepair *p = q->queue[i];
 627                 if (!identical(p->one, p->two))
 628                         return 0;
 629         }
 630         return 1;
 631 }
 632
 633 void diff_flush(const char **pathspec_, int speccnt_)
 634 {
 635         struct diff_queue_struct *q = &diff_queued_diff;
 636         int i;
 637
 638         pathspec = pathspec_;
 639         speccnt = speccnt_;
 640
 641         for (i = 0; i < q->nr; i++)
 642                 diff_flush_one(q->queue[i]);
 643
 644         for (i = 0; i < q->nr; i++) {
 645                 struct diff_filepair *p = q->queue[i];
 646                 diff_free_filespec_data(p->one);
 647                 diff_free_filespec_data(p->two);
 648                 free(p->xfrm_msg);
 649                 free(p);
 650         }
 651         free(q->queue);
 652         q->queue = NULL;
 653         q->nr = q->alloc = 0;
 654 }
 655
 656 void diff_addremove(int addremove, unsigned mode,
 657                     const unsigned char *sha1,
 658                     const char *base, const char *path)
 659 {
 660         char concatpath[PATH_MAX];
 661         struct diff_filespec *one, *two;
 662
 663         /* This may look odd, but it is a preparation for
 664          * feeding "there are unchanged files which should
 665          * not produce diffs, but when you are doing copy
 666          * detection you would need them, so here they are"
 667          * entries to the diff-core.  They will be prefixed
 668          * with something like '=' or '*' (I haven't decided
 669          * which but should not make any difference).
 670          * Feeding the same new and old to diff_change() should
 671          * also have the same effect.  diff_flush() should
 672          * filter the identical ones out at the final output
 673          * stage.
 674          */
 675         if (reverse_diff)
 676                 addremove = (addremove == '+' ? '-' :
 677                              addremove == '-' ? '+' : addremove);
 678
 679         if (!path) path = "";
 680         sprintf(concatpath, "%s%s", base, path);
 681         one = alloc_filespec(concatpath);
 682         two = alloc_filespec(concatpath);
 683
 684         if (addremove != '+')
 685                 fill_filespec(one, sha1, mode);
 686         if (addremove != '-')
 687                 fill_filespec(two, sha1, mode);
 688
 689         diff_queue(&diff_queued_diff, one, two);
 690 }
 691
 692 void diff_guif(unsigned old_mode,
 693                unsigned new_mode,
 694                const unsigned char *old_sha1,
 695                const unsigned char *new_sha1,
 696                const char *old_path,
 697                const char *new_path)
 698 {
 699         struct diff_filespec *one, *two;
 700
 701         if (reverse_diff) {
 702                 unsigned tmp;
 703                 const unsigned char *tmp_c;
 704                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
 705                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
 706         }
 707         one = alloc_filespec(old_path);
 708         two = alloc_filespec(new_path);
 709         if (old_mode)
 710                 fill_filespec(one, old_sha1, old_mode);
 711         if (new_mode)
 712                 fill_filespec(two, new_sha1, new_mode);
 713         diff_queue(&diff_queued_diff, one, two);
 714 }
 715
 716 void diff_change(unsigned old_mode, unsigned new_mode,
 717                  const unsigned char *old_sha1,
 718                  const unsigned char *new_sha1,
 719                  const char *base, const char *path)
 720 {
 721         char concatpath[PATH_MAX];
 722         struct diff_filespec *one, *two;
 723
 724         if (reverse_diff) {
 725                 unsigned tmp;
 726                 const unsigned char *tmp_c;
 727                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
 728                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
 729         }
 730         if (!path) path = "";
 731         sprintf(concatpath, "%s%s", base, path);
 732         one = alloc_filespec(concatpath);
 733         two = alloc_filespec(concatpath);
 734         fill_filespec(one, old_sha1, old_mode);
 735         fill_filespec(two, new_sha1, new_mode);
 736
 737         diff_queue(&diff_queued_diff, one, two);
 738 }
 739
 740 void diff_unmerge(const char *path)
 741 {
 742         if (generate_patch)
 743                 run_external_diff(path, NULL, NULL, NULL, NULL);
 744         else
 745                 printf("U %s%c", path, line_termination);
 746 }