combine-diff.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "diff.h"
   4 #include "diffcore.h"
   5 #include "quote.h"
   6
   7 static int uninteresting(struct diff_filepair *p)
   8 {
   9         if (diff_unmodified_pair(p))
  10                 return 1;
  11         if (!S_ISREG(p->one->mode) || !S_ISREG(p->two->mode))
  12                 return 1;
  13         return 0;
  14 }
  15
  16 static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
  17 {
  18         struct diff_queue_struct *q = &diff_queued_diff;
  19         struct combine_diff_path *p;
  20         int i;
  21
  22         if (!n) {
  23                 struct combine_diff_path *list = NULL, **tail = &list;
  24                 for (i = 0; i < q->nr; i++) {
  25                         int len;
  26                         const char *path;
  27                         if (uninteresting(q->queue[i]))
  28                                 continue;
  29                         path = q->queue[i]->two->path;
  30                         len = strlen(path);
  31
  32                         p = xmalloc(sizeof(*p) + len + 1 + num_parent * 20);
  33                         p->path = (char*) &(p->parent_sha1[num_parent][0]);
  34                         memcpy(p->path, path, len);
  35                         p->path[len] = 0;
  36                         p->len = len;
  37                         p->next = NULL;
  38                         memcpy(p->sha1, q->queue[i]->two->sha1, 20);
  39                         memcpy(p->parent_sha1[n], q->queue[i]->one->sha1, 20);
  40                         *tail = p;
  41                         tail = &p->next;
  42                 }
  43                 return list;
  44         }
  45
  46         for (p = curr; p; p = p->next) {
  47                 int found = 0;
  48                 if (!p->len)
  49                         continue;
  50                 for (i = 0; i < q->nr; i++) {
  51                         const char *path;
  52                         int len;
  53
  54                         if (uninteresting(q->queue[i]))
  55                                 continue;
  56                         path = q->queue[i]->two->path;
  57                         len = strlen(path);
  58                         if (len == p->len && !memcmp(path, p->path, len)) {
  59                                 found = 1;
  60                                 memcpy(p->parent_sha1[n],
  61                                        q->queue[i]->one->sha1, 20);
  62                                 break;
  63                         }
  64                 }
  65                 if (!found)
  66                         p->len = 0;
  67         }
  68         return curr;
  69 }
  70
  71 /* Lines lost from parent */
  72 struct lline {
  73         struct lline *next;
  74         int len;
  75         unsigned long parent_map;
  76         char line[FLEX_ARRAY];
  77 };
  78
  79 /* Lines surviving in the merge result */
  80 struct sline {
  81         struct lline *lost_head, **lost_tail;
  82         char *bol;
  83         int len;
  84         /* bit 0 up to (N-1) are on if the parent does _not_
  85          * have this line (i.e. we changed it).
  86          * bit N is used for "interesting" lines, including context.
  87          */
  88         unsigned long flag;
  89 };
  90
  91 static char *grab_blob(const unsigned char *sha1, unsigned long *size)
  92 {
  93         char *blob;
  94         char type[20];
  95         if (!memcmp(sha1, null_sha1, 20)) {
  96                 /* deleted blob */
  97                 *size = 0;
  98                 return xcalloc(1, 1);
  99         }
 100         blob = read_sha1_file(sha1, type, size);
 101         if (strcmp(type, "blob"))
 102                 die("object '%s' is not a blob!", sha1_to_hex(sha1));
 103         return blob;
 104 }
 105
 106 #define TMPPATHLEN 50
 107 #define MAXLINELEN 10240
 108
 109 static void write_to_temp_file(char *tmpfile, void *blob, unsigned long size)
 110 {
 111         int fd = git_mkstemp(tmpfile, TMPPATHLEN, ".diff_XXXXXX");
 112         if (fd < 0)
 113                 die("unable to create temp-file");
 114         if (write(fd, blob, size) != size)
 115                 die("unable to write temp-file");
 116         close(fd);
 117 }
 118
 119 static void write_temp_blob(char *tmpfile, const unsigned char *sha1)
 120 {
 121         unsigned long size;
 122         void *blob;
 123         blob = grab_blob(sha1, &size);
 124         write_to_temp_file(tmpfile, blob, size);
 125         free(blob);
 126 }
 127
 128 static int parse_num(char **cp_p, unsigned int *num_p)
 129 {
 130         char *cp = *cp_p;
 131         unsigned int num = 0;
 132         int read_some;
 133
 134         while ('0' <= *cp && *cp <= '9')
 135                 num = num * 10 + *cp++ - '0';
 136         if (!(read_some = cp - *cp_p))
 137                 return -1;
 138         *cp_p = cp;
 139         *num_p = num;
 140         return 0;
 141 }
 142
 143 static int parse_hunk_header(char *line, int len,
 144                              unsigned int *ob, unsigned int *on,
 145                              unsigned int *nb, unsigned int *nn)
 146 {
 147         char *cp;
 148         cp = line + 4;
 149         if (parse_num(&cp, ob)) {
 150         bad_line:
 151                 return error("malformed diff output: %s", line);
 152         }
 153         if (*cp == ',') {
 154                 cp++;
 155                 if (parse_num(&cp, on))
 156                         goto bad_line;
 157         }
 158         else
 159                 *on = 1;
 160         if (*cp++ != ' ' || *cp++ != '+')
 161                 goto bad_line;
 162         if (parse_num(&cp, nb))
 163                 goto bad_line;
 164         if (*cp == ',') {
 165                 cp++;
 166                 if (parse_num(&cp, nn))
 167                         goto bad_line;
 168         }
 169         else
 170                 *nn = 1;
 171         return -!!memcmp(cp, " @@", 3);
 172 }
 173
 174 static void append_lost(struct sline *sline, int n, const char *line)
 175 {
 176         struct lline *lline;
 177         int len = strlen(line);
 178         unsigned long this_mask = (1UL<<n);
 179         if (line[len-1] == '\n')
 180                 len--;
 181
 182         /* Check to see if we can squash things */
 183         if (sline->lost_head) {
 184                 struct lline *last_one = NULL;
 185                 /* We cannot squash it with earlier one */
 186                 for (lline = sline->lost_head;
 187                      lline;
 188                      lline = lline->next)
 189                         if (lline->parent_map & this_mask)
 190                                 last_one = lline;
 191                 lline = last_one ? last_one->next : sline->lost_head;
 192                 while (lline) {
 193                         if (lline->len == len &&
 194                             !memcmp(lline->line, line, len)) {
 195                                 lline->parent_map |= this_mask;
 196                                 return;
 197                         }
 198                         lline = lline->next;
 199                 }
 200         }
 201
 202         lline = xmalloc(sizeof(*lline) + len + 1);
 203         lline->len = len;
 204         lline->next = NULL;
 205         lline->parent_map = this_mask;
 206         memcpy(lline->line, line, len);
 207         lline->line[len] = 0;
 208         *sline->lost_tail = lline;
 209         sline->lost_tail = &lline->next;
 210 }
 211
 212 static void combine_diff(const unsigned char *parent, const char *ourtmp,
 213                          struct sline *sline, int cnt, int n)
 214 {
 215         FILE *in;
 216         char parent_tmp[TMPPATHLEN];
 217         char cmd[TMPPATHLEN * 2 + 1024];
 218         char line[MAXLINELEN];
 219         unsigned int lno, ob, on, nb, nn;
 220         unsigned long pmask = ~(1UL << n);
 221         struct sline *lost_bucket = NULL;
 222
 223         write_temp_blob(parent_tmp, parent);
 224         sprintf(cmd, "diff --unified=0 -La/x -Lb/x '%s' '%s'",
 225                 parent_tmp, ourtmp);
 226         in = popen(cmd, "r");
 227         if (!in)
 228                 return;
 229
 230         lno = 1;
 231         while (fgets(line, sizeof(line), in) != NULL) {
 232                 int len = strlen(line);
 233                 if (5 < len && !memcmp("@@ -", line, 4)) {
 234                         if (parse_hunk_header(line, len,
 235                                               &ob, &on, &nb, &nn))
 236                                 break;
 237                         lno = nb;
 238                         if (!nb) {
 239                                 /* @@ -1,2 +0,0 @@ to remove the
 240                                  * first two lines...
 241                                  */
 242                                 nb = 1;
 243                         }
 244                         if (nn == 0)
 245                                 lost_bucket = &sline[nb];
 246                         else
 247                                 lost_bucket = &sline[nb-1];
 248                         continue;
 249                 }
 250                 if (!lost_bucket)
 251                         continue; /* not in any hunk yet */
 252                 switch (line[0]) {
 253                 case '-':
 254                         append_lost(lost_bucket, n, line+1);
 255                         break;
 256                 case '+':
 257                         sline[lno-1].flag &= pmask;
 258                         lno++;
 259                         break;
 260                 }
 261         }
 262         fclose(in);
 263         unlink(parent_tmp);
 264 }
 265
 266 static unsigned long context = 3;
 267 static char combine_marker = '@';
 268
 269 static int interesting(struct sline *sline, unsigned long all_mask)
 270 {
 271         return ((sline->flag & all_mask) != all_mask || sline->lost_head);
 272 }
 273
 274 static unsigned long adjust_hunk_tail(struct sline *sline,
 275                                       unsigned long all_mask,
 276                                       unsigned long hunk_begin,
 277                                       unsigned long i)
 278 {
 279         /* i points at the first uninteresting line.
 280          * If the last line of the hunk was interesting
 281          * only because it has some deletion, then
 282          * it is not all that interesting for the
 283          * purpose of giving trailing context lines.
 284          */
 285         if ((hunk_begin + 1 <= i) &&
 286             ((sline[i-1].flag & all_mask) == all_mask))
 287                 i--;
 288         return i;
 289 }
 290
 291 static unsigned long next_interesting(struct sline *sline,
 292                                       unsigned long mark,
 293                                       unsigned long i,
 294                                       unsigned long cnt,
 295                                       int uninteresting)
 296 {
 297         while (i < cnt)
 298                 if (uninteresting ?
 299                     !(sline[i].flag & mark) :
 300                     (sline[i].flag & mark))
 301                         return i;
 302                 else
 303                         i++;
 304         return cnt;
 305 }
 306
 307 static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 308 {
 309         unsigned long all_mask = (1UL<<num_parent) - 1;
 310         unsigned long mark = (1UL<<num_parent);
 311         unsigned long i;
 312
 313         i = next_interesting(sline, mark, 0, cnt, 0);
 314         if (cnt <= i)
 315                 return 0;
 316
 317         while (i < cnt) {
 318                 unsigned long j = (context < i) ? (i - context) : 0;
 319                 unsigned long k;
 320                 while (j < i)
 321                         sline[j++].flag |= mark;
 322
 323         again:
 324                 j = next_interesting(sline, mark, i, cnt, 1);
 325                 if (cnt <= j)
 326                         break; /* the rest are all interesting */
 327
 328                 /* lookahead context lines */
 329                 k = next_interesting(sline, mark, j, cnt, 0);
 330                 j = adjust_hunk_tail(sline, all_mask, i, j);
 331
 332                 if (k < j + context) {
 333                         /* k is interesting and [j,k) are not, but
 334                          * paint them interesting because the gap is small.
 335                          */
 336                         while (j < k)
 337                                 sline[j++].flag |= mark;
 338                         i = k;
 339                         goto again;
 340                 }
 341
 342                 /* j is the first uninteresting line and there is
 343                  * no overlap beyond it within context lines.
 344                  */
 345                 i = k;
 346                 k = (j + context < cnt) ? j + context : cnt;
 347                 while (j < k)
 348                         sline[j++].flag |= mark;
 349         }
 350         return 1;
 351 }
 352
 353 static int make_hunks(struct sline *sline, unsigned long cnt,
 354                        int num_parent, int dense)
 355 {
 356         unsigned long all_mask = (1UL<<num_parent) - 1;
 357         unsigned long mark = (1UL<<num_parent);
 358         unsigned long i;
 359         int has_interesting = 0;
 360
 361         for (i = 0; i < cnt; i++) {
 362                 if (interesting(&sline[i], all_mask))
 363                         sline[i].flag |= mark;
 364                 else
 365                         sline[i].flag &= ~mark;
 366         }
 367         if (!dense)
 368                 return give_context(sline, cnt, num_parent);
 369
 370         /* Look at each hunk, and if we have changes from only one
 371          * parent, or the changes are the same from all but one
 372          * parent, mark that uninteresting.
 373          */
 374         i = 0;
 375         while (i < cnt) {
 376                 unsigned long j, hunk_begin, hunk_end;
 377                 unsigned long same_diff;
 378                 while (i < cnt && !(sline[i].flag & mark))
 379                         i++;
 380                 if (cnt <= i)
 381                         break; /* No more interesting hunks */
 382                 hunk_begin = i;
 383                 for (j = i + 1; j < cnt; j++) {
 384                         if (!(sline[j].flag & mark)) {
 385                                 /* Look beyond the end to see if there
 386                                  * is an interesting line after this
 387                                  * hunk within context span.
 388                                  */
 389                                 unsigned long la; /* lookahead */
 390                                 int contin = 0;
 391                                 la = adjust_hunk_tail(sline, all_mask,
 392                                                      hunk_begin, j);
 393                                 la = (la + context < cnt) ?
 394                                         (la + context) : cnt;
 395                                 while (j <= --la) {
 396                                         if (sline[la].flag & mark) {
 397                                                 contin = 1;
 398                                                 break;
 399                                         }
 400                                 }
 401                                 if (!contin)
 402                                         break;
 403                                 j = la;
 404                         }
 405                 }
 406                 hunk_end = j;
 407
 408                 /* [i..hunk_end) are interesting.  Now is it really
 409                  * interesting?  We check if there are only two versions
 410                  * and the result matches one of them.  That is, we look
 411                  * at:
 412                  *   (+) line, which records lines added to which parents;
 413                  *       this line appears in the result.
 414                  *   (-) line, which records from what parents the line
 415                  *       was removed; this line does not appear in the result.
 416                  * then check the set of parents the result has difference
 417                  * from, from all lines.  If there are lines that has
 418                  * different set of parents that the result has differences
 419                  * from, that means we have more than two versions.
 420                  *
 421                  * Even when we have only two versions, if the result does
 422                  * not match any of the parents, the it should be considered
 423                  * interesting.  In such a case, we would have all '+' line.
 424                  * After passing the above "two versions" test, that would
 425                  * appear as "the same set of parents" to be "all parents".
 426                  */
 427                 same_diff = 0;
 428                 has_interesting = 0;
 429                 for (j = i; j < hunk_end && !has_interesting; j++) {
 430                         unsigned long this_diff = ~sline[j].flag & all_mask;
 431                         struct lline *ll = sline[j].lost_head;
 432                         if (this_diff) {
 433                                 /* This has some changes.  Is it the
 434                                  * same as others?
 435                                  */
 436                                 if (!same_diff)
 437                                         same_diff = this_diff;
 438                                 else if (same_diff != this_diff) {
 439                                         has_interesting = 1;
 440                                         break;
 441                                 }
 442                         }
 443                         while (ll && !has_interesting) {
 444                                 /* Lost this line from these parents;
 445                                  * who are they?  Are they the same?
 446                                  */
 447                                 this_diff = ll->parent_map;
 448                                 if (!same_diff)
 449                                         same_diff = this_diff;
 450                                 else if (same_diff != this_diff) {
 451                                         has_interesting = 1;
 452                                 }
 453                                 ll = ll->next;
 454                         }
 455                 }
 456
 457                 if (!has_interesting && same_diff != all_mask) {
 458                         /* This hunk is not that interesting after all */
 459                         for (j = hunk_begin; j < hunk_end; j++)
 460                                 sline[j].flag &= ~mark;
 461                 }
 462                 i = hunk_end;
 463         }
 464
 465         has_interesting = give_context(sline, cnt, num_parent);
 466         return has_interesting;
 467 }
 468
 469 static void dump_sline(struct sline *sline, int cnt, int num_parent)
 470 {
 471         unsigned long mark = (1UL<<num_parent);
 472         int i;
 473         int lno = 0;
 474
 475         while (1) {
 476                 struct sline *sl = &sline[lno];
 477                 int hunk_end;
 478                 while (lno < cnt && !(sline[lno].flag & mark))
 479                         lno++;
 480                 if (cnt <= lno)
 481                         break;
 482                 for (hunk_end = lno + 1; hunk_end < cnt; hunk_end++)
 483                         if (!(sline[hunk_end].flag & mark))
 484                                 break;
 485                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 486                 printf(" +%d,%d ", lno+1, hunk_end-lno);
 487                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 488                 putchar('\n');
 489                 while (lno < hunk_end) {
 490                         struct lline *ll;
 491                         int j;
 492                         sl = &sline[lno++];
 493                         ll = sl->lost_head;
 494                         while (ll) {
 495                                 for (j = 0; j < num_parent; j++) {
 496                                         if (ll->parent_map & (1UL<<j))
 497                                                 putchar('-');
 498                                         else
 499                                                 putchar(' ');
 500                                 }
 501                                 puts(ll->line);
 502                                 ll = ll->next;
 503                         }
 504                         for (j = 0; j < num_parent; j++) {
 505                                 if ((1UL<<j) & sl->flag)
 506                                         putchar(' ');
 507                                 else
 508                                         putchar('+');
 509                         }
 510                         printf("%.*s\n", sl->len, sl->bol);
 511                 }
 512         }
 513 }
 514
 515 static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 516                                int i, int j)
 517 {
 518         /* We have already examined parent j and we know parent i
 519          * and parent j are the same, so reuse the combined result
 520          * of parent j for parent i.
 521          */
 522         unsigned long lno, imask, jmask;
 523         imask = (1UL<<i);
 524         jmask = (1UL<<j);
 525
 526         for (lno = 0; lno < cnt; lno++) {
 527                 struct lline *ll = sline->lost_head;
 528                 while (ll) {
 529                         if (ll->parent_map & jmask)
 530                                 ll->parent_map |= imask;
 531                         ll = ll->next;
 532                 }
 533                 if (!(sline->flag & jmask))
 534                         sline->flag &= ~imask;
 535                 sline++;
 536         }
 537 }
 538
 539 int show_combined_diff(struct combine_diff_path *elem, int num_parent,
 540                        int dense, const char *header, int show_empty)
 541 {
 542         unsigned long size, cnt, lno;
 543         char *result, *cp, *ep;
 544         struct sline *sline; /* survived lines */
 545         int i, show_hunks, shown_header = 0;
 546         char ourtmp_buf[TMPPATHLEN];
 547         char *ourtmp = ourtmp_buf;
 548
 549         /* Read the result of merge first */
 550         if (memcmp(elem->sha1, null_sha1, 20)) {
 551                 result = grab_blob(elem->sha1, &size);
 552                 write_to_temp_file(ourtmp, result, size);
 553         }
 554         else {
 555                 struct stat st;
 556                 int fd;
 557                 ourtmp = elem->path;
 558                 if (0 <= (fd = open(ourtmp, O_RDONLY)) &&
 559                     !fstat(fd, &st)) {
 560                         int len = st.st_size;
 561                         int cnt = 0;
 562
 563                         size = len;
 564                         result = xmalloc(len + 1);
 565                         while (cnt < len) {
 566                                 int done = xread(fd, result+cnt, len-cnt);
 567                                 if (done == 0)
 568                                         break;
 569                                 if (done < 0)
 570                                         die("read error '%s'", ourtmp);
 571                                 cnt += done;
 572                         }
 573                         result[len] = 0;
 574                 }
 575                 else {
 576                         /* deleted file */
 577                         size = 0;
 578                         result = xmalloc(1);
 579                         result[0] = 0;
 580                         ourtmp = "/dev/null";
 581                 }
 582                 if (0 <= fd)
 583                         close(fd);
 584         }
 585
 586         for (cnt = 0, cp = result; cp - result < size; cp++) {
 587                 if (*cp == '\n')
 588                         cnt++;
 589         }
 590         if (result[size-1] != '\n')
 591                 cnt++; /* incomplete line */
 592
 593         sline = xcalloc(cnt, sizeof(*sline));
 594         ep = result;
 595         sline[0].bol = result;
 596         for (lno = 0, cp = result; cp - result < size; cp++) {
 597                 if (*cp == '\n') {
 598                         sline[lno].lost_tail = &sline[lno].lost_head;
 599                         sline[lno].len = cp - sline[lno].bol;
 600                         sline[lno].flag = (1UL<<num_parent) - 1;
 601                         lno++;
 602                         if (lno < cnt)
 603                                 sline[lno].bol = cp + 1;
 604                 }
 605         }
 606         if (result[size-1] != '\n') {
 607                 sline[cnt-1].lost_tail = &sline[cnt-1].lost_head;
 608                 sline[cnt-1].len = size - (sline[cnt-1].bol - result);
 609                 sline[cnt-1].flag = (1UL<<num_parent) - 1;
 610         }
 611
 612         for (i = 0; i < num_parent; i++) {
 613                 int j;
 614                 for (j = 0; j < i; j++) {
 615                         if (!memcmp(elem->parent_sha1[i],
 616                                     elem->parent_sha1[j], 20)) {
 617                                 reuse_combine_diff(sline, cnt, i, j);
 618                                 break;
 619                         }
 620                 }
 621                 if (i <= j)
 622                         combine_diff(elem->parent_sha1[i], ourtmp, sline,
 623                                      cnt, i);
 624         }
 625
 626         show_hunks = make_hunks(sline, cnt, num_parent, dense);
 627
 628         if (header && (show_hunks || show_empty)) {
 629                 shown_header++;
 630                 puts(header);
 631         }
 632         if (show_hunks) {
 633                 printf("diff --%s ", dense ? "cc" : "combined");
 634                 if (quote_c_style(elem->path, NULL, NULL, 0))
 635                         quote_c_style(elem->path, NULL, stdout, 0);
 636                 else
 637                         printf("%s", elem->path);
 638                 putchar('\n');
 639                 printf("index ");
 640                 for (i = 0; i < num_parent; i++) {
 641                         printf("%s%s",
 642                                i ? ".." : "",
 643                                find_unique_abbrev(elem->parent_sha1[i],
 644                                                   DEFAULT_ABBREV));
 645                 }
 646                 printf("->%s\n",
 647                        find_unique_abbrev(elem->sha1, DEFAULT_ABBREV));
 648                 dump_sline(sline, cnt, num_parent);
 649         }
 650         if (ourtmp == ourtmp_buf)
 651                 unlink(ourtmp);
 652         free(result);
 653
 654         for (i = 0; i < cnt; i++) {
 655                 if (sline[i].lost_head) {
 656                         struct lline *ll = sline[i].lost_head;
 657                         while (ll) {
 658                                 struct lline *tmp = ll;
 659                                 ll = ll->next;
 660                                 free(tmp);
 661                         }
 662                 }
 663         }
 664         free(sline);
 665         return shown_header;
 666 }
 667
 668 int diff_tree_combined_merge(const unsigned char *sha1,
 669                              const char *header,
 670                              int show_empty_merge, int dense)
 671 {
 672         struct commit *commit = lookup_commit(sha1);
 673         struct diff_options diffopts;
 674         struct commit_list *parents;
 675         struct combine_diff_path *p, *paths = NULL;
 676         int num_parent, i, num_paths;
 677
 678         diff_setup(&diffopts);
 679         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
 680         diffopts.recursive = 1;
 681
 682         /* count parents */
 683         for (parents = commit->parents, num_parent = 0;
 684              parents;
 685              parents = parents->next, num_parent++)
 686                 ; /* nothing */
 687
 688         /* find set of paths that everybody touches */
 689         for (parents = commit->parents, i = 0;
 690              parents;
 691              parents = parents->next, i++) {
 692                 struct commit *parent = parents->item;
 693                 diff_tree_sha1(parent->object.sha1, commit->object.sha1, "",
 694                                &diffopts);
 695                 paths = intersect_paths(paths, i, num_parent);
 696                 diff_flush(&diffopts);
 697         }
 698
 699         /* find out surviving paths */
 700         for (num_paths = 0, p = paths; p; p = p->next) {
 701                 if (p->len)
 702                         num_paths++;
 703         }
 704         if (num_paths || show_empty_merge) {
 705                 for (p = paths; p; p = p->next) {
 706                         if (!p->len)
 707                                 continue;
 708                         if (show_combined_diff(p, num_parent, dense, header,
 709                                                show_empty_merge))
 710                                 header = NULL;
 711                 }
 712         }
 713
 714         /* Clean things up */
 715         while (paths) {
 716                 struct combine_diff_path *tmp = paths;
 717                 paths = paths->next;
 718                 free(tmp);
 719         }
 720         return 0;
 721 }