git.oblomov.eu Git - git/blob - combine-diff.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "blob.h"
   4 #include "diff.h"
   5 #include "diffcore.h"
   6 #include "quote.h"
   7 #include "xdiff-interface.h"
   8 #include "log-tree.h"
   9
  10 static int uninteresting(struct diff_filepair *p)
  11 {
  12         if (diff_unmodified_pair(p))
  13                 return 1;
  14         return 0;
  15 }
  16
  17 static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
  18 {
  19         struct diff_queue_struct *q = &diff_queued_diff;
  20         struct combine_diff_path *p;
  21         int i;
  22
  23         if (!n) {
  24                 struct combine_diff_path *list = NULL, **tail = &list;
  25                 for (i = 0; i < q->nr; i++) {
  26                         int len;
  27                         const char *path;
  28                         if (uninteresting(q->queue[i]))
  29                                 continue;
  30                         path = q->queue[i]->two->path;
  31                         len = strlen(path);
  32                         p = xmalloc(combine_diff_path_size(num_parent, len));
  33                         p->path = (char*) &(p->parent[num_parent]);
  34                         memcpy(p->path, path, len);
  35                         p->path[len] = 0;
  36                         p->len = len;
  37                         p->next = NULL;
  38                         memset(p->parent, 0,
  39                                sizeof(p->parent[0]) * num_parent);
  40
  41                         memcpy(p->sha1, q->queue[i]->two->sha1, 20);
  42                         p->mode = q->queue[i]->two->mode;
  43                         memcpy(p->parent[n].sha1, q->queue[i]->one->sha1, 20);
  44                         p->parent[n].mode = q->queue[i]->one->mode;
  45                         p->parent[n].status = q->queue[i]->status;
  46                         *tail = p;
  47                         tail = &p->next;
  48                 }
  49                 return list;
  50         }
  51
  52         for (p = curr; p; p = p->next) {
  53                 int found = 0;
  54                 if (!p->len)
  55                         continue;
  56                 for (i = 0; i < q->nr; i++) {
  57                         const char *path;
  58                         int len;
  59
  60                         if (uninteresting(q->queue[i]))
  61                                 continue;
  62                         path = q->queue[i]->two->path;
  63                         len = strlen(path);
  64                         if (len == p->len && !memcmp(path, p->path, len)) {
  65                                 found = 1;
  66                                 memcpy(p->parent[n].sha1,
  67                                        q->queue[i]->one->sha1, 20);
  68                                 p->parent[n].mode = q->queue[i]->one->mode;
  69                                 p->parent[n].status = q->queue[i]->status;
  70                                 break;
  71                         }
  72                 }
  73                 if (!found)
  74                         p->len = 0;
  75         }
  76         return curr;
  77 }
  78
  79 /* Lines lost from parent */
  80 struct lline {
  81         struct lline *next;
  82         int len;
  83         unsigned long parent_map;
  84         char line[FLEX_ARRAY];
  85 };
  86
  87 /* Lines surviving in the merge result */
  88 struct sline {
  89         struct lline *lost_head, **lost_tail;
  90         char *bol;
  91         int len;
  92         /* bit 0 up to (N-1) are on if the parent has this line (i.e.
  93          * we did not change it).
  94          * bit N is used for "interesting" lines, including context.
  95          */
  96         unsigned long flag;
  97         unsigned long *p_lno;
  98 };
  99
 100 static char *grab_blob(const unsigned char *sha1, unsigned long *size)
 101 {
 102         char *blob;
 103         char type[20];
 104         if (!memcmp(sha1, null_sha1, 20)) {
 105                 /* deleted blob */
 106                 *size = 0;
 107                 return xcalloc(1, 1);
 108         }
 109         blob = read_sha1_file(sha1, type, size);
 110         if (strcmp(type, blob_type))
 111                 die("object '%s' is not a blob!", sha1_to_hex(sha1));
 112         return blob;
 113 }
 114
 115 static void append_lost(struct sline *sline, int n, const char *line, int len)
 116 {
 117         struct lline *lline;
 118         unsigned long this_mask = (1UL<<n);
 119         if (line[len-1] == '\n')
 120                 len--;
 121
 122         /* Check to see if we can squash things */
 123         if (sline->lost_head) {
 124                 struct lline *last_one = NULL;
 125                 /* We cannot squash it with earlier one */
 126                 for (lline = sline->lost_head;
 127                      lline;
 128                      lline = lline->next)
 129                         if (lline->parent_map & this_mask)
 130                                 last_one = lline;
 131                 lline = last_one ? last_one->next : sline->lost_head;
 132                 while (lline) {
 133                         if (lline->len == len &&
 134                             !memcmp(lline->line, line, len)) {
 135                                 lline->parent_map |= this_mask;
 136                                 return;
 137                         }
 138                         lline = lline->next;
 139                 }
 140         }
 141
 142         lline = xmalloc(sizeof(*lline) + len + 1);
 143         lline->len = len;
 144         lline->next = NULL;
 145         lline->parent_map = this_mask;
 146         memcpy(lline->line, line, len);
 147         lline->line[len] = 0;
 148         *sline->lost_tail = lline;
 149         sline->lost_tail = &lline->next;
 150 }
 151
 152 struct combine_diff_state {
 153         struct xdiff_emit_state xm;
 154
 155         unsigned int lno;
 156         int ob, on, nb, nn;
 157         unsigned long nmask;
 158         int num_parent;
 159         int n;
 160         struct sline *sline;
 161         struct sline *lost_bucket;
 162 };
 163
 164 static void consume_line(void *state_, char *line, unsigned long len)
 165 {
 166         struct combine_diff_state *state = state_;
 167         if (5 < len && !memcmp("@@ -", line, 4)) {
 168                 if (parse_hunk_header(line, len,
 169                                       &state->ob, &state->on,
 170                                       &state->nb, &state->nn))
 171                         return;
 172                 state->lno = state->nb;
 173                 if (!state->nb)
 174                         /* @@ -1,2 +0,0 @@ to remove the
 175                          * first two lines...
 176                          */
 177                         state->nb = 1;
 178                 if (state->nn == 0)
 179                         /* @@ -X,Y +N,0 @@ removed Y lines
 180                          * that would have come *after* line N
 181                          * in the result.  Our lost buckets hang
 182                          * to the line after the removed lines,
 183                          */
 184                         state->lost_bucket = &state->sline[state->nb];
 185                 else
 186                         state->lost_bucket = &state->sline[state->nb-1];
 187                 if (!state->sline[state->nb-1].p_lno)
 188                         state->sline[state->nb-1].p_lno =
 189                                 xcalloc(state->num_parent,
 190                                         sizeof(unsigned long));
 191                 state->sline[state->nb-1].p_lno[state->n] = state->ob;
 192                 return;
 193         }
 194         if (!state->lost_bucket)
 195                 return; /* not in any hunk yet */
 196         switch (line[0]) {
 197         case '-':
 198                 append_lost(state->lost_bucket, state->n, line+1, len-1);
 199                 break;
 200         case '+':
 201                 state->sline[state->lno-1].flag |= state->nmask;
 202                 state->lno++;
 203                 break;
 204         }
 205 }
 206
 207 static void combine_diff(const unsigned char *parent, mmfile_t *result_file,
 208                          struct sline *sline, unsigned int cnt, int n,
 209                          int num_parent)
 210 {
 211         unsigned int p_lno, lno;
 212         unsigned long nmask = (1UL << n);
 213         xpparam_t xpp;
 214         xdemitconf_t xecfg;
 215         mmfile_t parent_file;
 216         xdemitcb_t ecb;
 217         struct combine_diff_state state;
 218         unsigned long sz;
 219
 220         if (!cnt)
 221                 return; /* result deleted */
 222
 223         parent_file.ptr = grab_blob(parent, &sz);
 224         parent_file.size = sz;
 225         xpp.flags = XDF_NEED_MINIMAL;
 226         xecfg.ctxlen = 0;
 227         xecfg.flags = 0;
 228         ecb.outf = xdiff_outf;
 229         ecb.priv = &state;
 230         memset(&state, 0, sizeof(state));
 231         state.xm.consume = consume_line;
 232         state.nmask = nmask;
 233         state.sline = sline;
 234         state.lno = 1;
 235         state.num_parent = num_parent;
 236         state.n = n;
 237
 238         xdl_diff(&parent_file, result_file, &xpp, &xecfg, &ecb);
 239         free(parent_file.ptr);
 240
 241         /* Assign line numbers for this parent.
 242          *
 243          * sline[lno].p_lno[n] records the first line number
 244          * (counting from 1) for parent N if the final hunk display
 245          * started by showing sline[lno] (possibly showing the lost
 246          * lines attached to it first).
 247          */
 248         for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
 249                 struct lline *ll;
 250                 sline[lno].p_lno[n] = p_lno;
 251
 252                 /* How many lines would this sline advance the p_lno? */
 253                 ll = sline[lno].lost_head;
 254                 while (ll) {
 255                         if (ll->parent_map & nmask)
 256                                 p_lno++; /* '-' means parent had it */
 257                         ll = ll->next;
 258                 }
 259                 if (lno < cnt && !(sline[lno].flag & nmask))
 260                         p_lno++; /* no '+' means parent had it */
 261         }
 262         sline[lno].p_lno[n] = p_lno; /* trailer */
 263 }
 264
 265 static unsigned long context = 3;
 266 static char combine_marker = '@';
 267
 268 static int interesting(struct sline *sline, unsigned long all_mask)
 269 {
 270         /* If some parents lost lines here, or if we have added to
 271          * some parent, it is interesting.
 272          */
 273         return ((sline->flag & all_mask) || sline->lost_head);
 274 }
 275
 276 static unsigned long adjust_hunk_tail(struct sline *sline,
 277                                       unsigned long all_mask,
 278                                       unsigned long hunk_begin,
 279                                       unsigned long i)
 280 {
 281         /* i points at the first uninteresting line.  If the last line
 282          * of the hunk was interesting only because it has some
 283          * deletion, then it is not all that interesting for the
 284          * purpose of giving trailing context lines.  This is because
 285          * we output '-' line and then unmodified sline[i-1] itself in
 286          * that case which gives us one extra context line.
 287          */
 288         if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
 289                 i--;
 290         return i;
 291 }
 292
 293 static unsigned long find_next(struct sline *sline,
 294                                unsigned long mark,
 295                                unsigned long i,
 296                                unsigned long cnt,
 297                                int look_for_uninteresting)
 298 {
 299         /* We have examined up to i-1 and are about to look at i.
 300          * Find next interesting or uninteresting line.  Here,
 301          * "interesting" does not mean interesting(), but marked by
 302          * the give_context() function below (i.e. it includes context
 303          * lines that are not interesting to interesting() function
 304          * that are surrounded by interesting() ones.
 305          */
 306         while (i <= cnt)
 307                 if (look_for_uninteresting
 308                     ? !(sline[i].flag & mark)
 309                     : (sline[i].flag & mark))
 310                         return i;
 311                 else
 312                         i++;
 313         return i;
 314 }
 315
 316 static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 317 {
 318         unsigned long all_mask = (1UL<<num_parent) - 1;
 319         unsigned long mark = (1UL<<num_parent);
 320         unsigned long i;
 321
 322         /* Two groups of interesting lines may have a short gap of
 323          * uninteresting lines.  Connect such groups to give them a
 324          * bit of context.
 325          *
 326          * We first start from what the interesting() function says,
 327          * and mark them with "mark", and paint context lines with the
 328          * mark.  So interesting() would still say false for such context
 329          * lines but they are treated as "interesting" in the end.
 330          */
 331         i = find_next(sline, mark, 0, cnt, 0);
 332         if (cnt < i)
 333                 return 0;
 334
 335         while (i <= cnt) {
 336                 unsigned long j = (context < i) ? (i - context) : 0;
 337                 unsigned long k;
 338
 339                 /* Paint a few lines before the first interesting line. */
 340                 while (j < i)
 341                         sline[j++].flag |= mark;
 342
 343         again:
 344                 /* we know up to i is to be included.  where does the
 345                  * next uninteresting one start?
 346                  */
 347                 j = find_next(sline, mark, i, cnt, 1);
 348                 if (cnt < j)
 349                         break; /* the rest are all interesting */
 350
 351                 /* lookahead context lines */
 352                 k = find_next(sline, mark, j, cnt, 0);
 353                 j = adjust_hunk_tail(sline, all_mask, i, j);
 354
 355                 if (k < j + context) {
 356                         /* k is interesting and [j,k) are not, but
 357                          * paint them interesting because the gap is small.
 358                          */
 359                         while (j < k)
 360                                 sline[j++].flag |= mark;
 361                         i = k;
 362                         goto again;
 363                 }
 364
 365                 /* j is the first uninteresting line and there is
 366                  * no overlap beyond it within context lines.  Paint
 367                  * the trailing edge a bit.
 368                  */
 369                 i = k;
 370                 k = (j + context < cnt+1) ? j + context : cnt+1;
 371                 while (j < k)
 372                         sline[j++].flag |= mark;
 373         }
 374         return 1;
 375 }
 376
 377 static int make_hunks(struct sline *sline, unsigned long cnt,
 378                        int num_parent, int dense)
 379 {
 380         unsigned long all_mask = (1UL<<num_parent) - 1;
 381         unsigned long mark = (1UL<<num_parent);
 382         unsigned long i;
 383         int has_interesting = 0;
 384
 385         for (i = 0; i <= cnt; i++) {
 386                 if (interesting(&sline[i], all_mask))
 387                         sline[i].flag |= mark;
 388                 else
 389                         sline[i].flag &= ~mark;
 390         }
 391         if (!dense)
 392                 return give_context(sline, cnt, num_parent);
 393
 394         /* Look at each hunk, and if we have changes from only one
 395          * parent, or the changes are the same from all but one
 396          * parent, mark that uninteresting.
 397          */
 398         i = 0;
 399         while (i <= cnt) {
 400                 unsigned long j, hunk_begin, hunk_end;
 401                 unsigned long same_diff;
 402                 while (i <= cnt && !(sline[i].flag & mark))
 403                         i++;
 404                 if (cnt < i)
 405                         break; /* No more interesting hunks */
 406                 hunk_begin = i;
 407                 for (j = i + 1; j <= cnt; j++) {
 408                         if (!(sline[j].flag & mark)) {
 409                                 /* Look beyond the end to see if there
 410                                  * is an interesting line after this
 411                                  * hunk within context span.
 412                                  */
 413                                 unsigned long la; /* lookahead */
 414                                 int contin = 0;
 415                                 la = adjust_hunk_tail(sline, all_mask,
 416                                                      hunk_begin, j);
 417                                 la = (la + context < cnt + 1) ?
 418                                         (la + context) : cnt + 1;
 419                                 while (j <= --la) {
 420                                         if (sline[la].flag & mark) {
 421                                                 contin = 1;
 422                                                 break;
 423                                         }
 424                                 }
 425                                 if (!contin)
 426                                         break;
 427                                 j = la;
 428                         }
 429                 }
 430                 hunk_end = j;
 431
 432                 /* [i..hunk_end) are interesting.  Now is it really
 433                  * interesting?  We check if there are only two versions
 434                  * and the result matches one of them.  That is, we look
 435                  * at:
 436                  *   (+) line, which records lines added to which parents;
 437                  *       this line appears in the result.
 438                  *   (-) line, which records from what parents the line
 439                  *       was removed; this line does not appear in the result.
 440                  * then check the set of parents the result has difference
 441                  * from, from all lines.  If there are lines that has
 442                  * different set of parents that the result has differences
 443                  * from, that means we have more than two versions.
 444                  *
 445                  * Even when we have only two versions, if the result does
 446                  * not match any of the parents, the it should be considered
 447                  * interesting.  In such a case, we would have all '+' line.
 448                  * After passing the above "two versions" test, that would
 449                  * appear as "the same set of parents" to be "all parents".
 450                  */
 451                 same_diff = 0;
 452                 has_interesting = 0;
 453                 for (j = i; j < hunk_end && !has_interesting; j++) {
 454                         unsigned long this_diff = sline[j].flag & all_mask;
 455                         struct lline *ll = sline[j].lost_head;
 456                         if (this_diff) {
 457                                 /* This has some changes.  Is it the
 458                                  * same as others?
 459                                  */
 460                                 if (!same_diff)
 461                                         same_diff = this_diff;
 462                                 else if (same_diff != this_diff) {
 463                                         has_interesting = 1;
 464                                         break;
 465                                 }
 466                         }
 467                         while (ll && !has_interesting) {
 468                                 /* Lost this line from these parents;
 469                                  * who are they?  Are they the same?
 470                                  */
 471                                 this_diff = ll->parent_map;
 472                                 if (!same_diff)
 473                                         same_diff = this_diff;
 474                                 else if (same_diff != this_diff) {
 475                                         has_interesting = 1;
 476                                 }
 477                                 ll = ll->next;
 478                         }
 479                 }
 480
 481                 if (!has_interesting && same_diff != all_mask) {
 482                         /* This hunk is not that interesting after all */
 483                         for (j = hunk_begin; j < hunk_end; j++)
 484                                 sline[j].flag &= ~mark;
 485                 }
 486                 i = hunk_end;
 487         }
 488
 489         has_interesting = give_context(sline, cnt, num_parent);
 490         return has_interesting;
 491 }
 492
 493 static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n)
 494 {
 495         l0 = sline[l0].p_lno[n];
 496         l1 = sline[l1].p_lno[n];
 497         printf(" -%lu,%lu", l0, l1-l0);
 498 }
 499
 500 static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent)
 501 {
 502         unsigned long mark = (1UL<<num_parent);
 503         int i;
 504         unsigned long lno = 0;
 505
 506         if (!cnt)
 507                 return; /* result deleted */
 508
 509         while (1) {
 510                 struct sline *sl = &sline[lno];
 511                 unsigned long hunk_end;
 512                 unsigned long rlines;
 513                 while (lno <= cnt && !(sline[lno].flag & mark))
 514                         lno++;
 515                 if (cnt < lno)
 516                         break;
 517                 else {
 518                         for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
 519                                 if (!(sline[hunk_end].flag & mark))
 520                                         break;
 521                 }
 522                 rlines = hunk_end - lno;
 523                 if (cnt < hunk_end)
 524                         rlines--; /* pointing at the last delete hunk */
 525                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 526                 for (i = 0; i < num_parent; i++)
 527                         show_parent_lno(sline, lno, hunk_end, i);
 528                 printf(" +%lu,%lu ", lno+1, rlines);
 529                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 530                 putchar('\n');
 531                 while (lno < hunk_end) {
 532                         struct lline *ll;
 533                         int j;
 534                         unsigned long p_mask;
 535                         sl = &sline[lno++];
 536                         ll = sl->lost_head;
 537                         while (ll) {
 538                                 for (j = 0; j < num_parent; j++) {
 539                                         if (ll->parent_map & (1UL<<j))
 540                                                 putchar('-');
 541                                         else
 542                                                 putchar(' ');
 543                                 }
 544                                 puts(ll->line);
 545                                 ll = ll->next;
 546                         }
 547                         if (cnt < lno)
 548                                 break;
 549                         p_mask = 1;
 550                         for (j = 0; j < num_parent; j++) {
 551                                 if (p_mask & sl->flag)
 552                                         putchar('+');
 553                                 else
 554                                         putchar(' ');
 555                                 p_mask <<= 1;
 556                         }
 557                         printf("%.*s\n", sl->len, sl->bol);
 558                 }
 559         }
 560 }
 561
 562 static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 563                                int i, int j)
 564 {
 565         /* We have already examined parent j and we know parent i
 566          * and parent j are the same, so reuse the combined result
 567          * of parent j for parent i.
 568          */
 569         unsigned long lno, imask, jmask;
 570         imask = (1UL<<i);
 571         jmask = (1UL<<j);
 572
 573         for (lno = 0; lno <= cnt; lno++) {
 574                 struct lline *ll = sline->lost_head;
 575                 sline->p_lno[i] = sline->p_lno[j];
 576                 while (ll) {
 577                         if (ll->parent_map & jmask)
 578                                 ll->parent_map |= imask;
 579                         ll = ll->next;
 580                 }
 581                 if (sline->flag & jmask)
 582                         sline->flag |= imask;
 583                 sline++;
 584         }
 585         /* the overall size of the file (sline[cnt]) */
 586         sline->p_lno[i] = sline->p_lno[j];
 587 }
 588
 589 static void dump_quoted_path(const char *prefix, const char *path)
 590 {
 591         fputs(prefix, stdout);
 592         if (quote_c_style(path, NULL, NULL, 0))
 593                 quote_c_style(path, NULL, stdout, 0);
 594         else
 595                 printf("%s", path);
 596         putchar('\n');
 597 }
 598
 599 static int show_patch_diff(struct combine_diff_path *elem, int num_parent,
 600                            int dense, struct rev_info *rev)
 601 {
 602         struct diff_options *opt = &rev->diffopt;
 603         unsigned long result_size, cnt, lno;
 604         char *result, *cp;
 605         struct sline *sline; /* survived lines */
 606         int mode_differs = 0;
 607         int i, show_hunks, shown_header = 0;
 608         int working_tree_file = !memcmp(elem->sha1, null_sha1, 20);
 609         int abbrev = opt->full_index ? 40 : DEFAULT_ABBREV;
 610         mmfile_t result_file;
 611
 612         context = opt->context;
 613         /* Read the result of merge first */
 614         if (!working_tree_file)
 615                 result = grab_blob(elem->sha1, &result_size);
 616         else {
 617                 /* Used by diff-tree to read from the working tree */
 618                 struct stat st;
 619                 int fd;
 620                 if (0 <= (fd = open(elem->path, O_RDONLY)) &&
 621                     !fstat(fd, &st)) {
 622                         int len = st.st_size;
 623                         int sz = 0;
 624
 625                         elem->mode = canon_mode(st.st_mode);
 626                         result_size = len;
 627                         result = xmalloc(len + 1);
 628                         while (sz < len) {
 629                                 int done = xread(fd, result+sz, len-sz);
 630                                 if (done == 0)
 631                                         break;
 632                                 if (done < 0)
 633                                         die("read error '%s'", elem->path);
 634                                 sz += done;
 635                         }
 636                         result[len] = 0;
 637                 }
 638                 else {
 639                         /* deleted file */
 640                         result_size = 0;
 641                         elem->mode = 0;
 642                         result = xmalloc(1);
 643                         result[0] = 0;
 644                 }
 645                 if (0 <= fd)
 646                         close(fd);
 647         }
 648
 649         for (cnt = 0, cp = result; cp < result + result_size; cp++) {
 650                 if (*cp == '\n')
 651                         cnt++;
 652         }
 653         if (result_size && result[result_size-1] != '\n')
 654                 cnt++; /* incomplete line */
 655
 656         sline = xcalloc(cnt+2, sizeof(*sline));
 657         sline[0].bol = result;
 658         for (lno = 0; lno <= cnt + 1; lno++) {
 659                 sline[lno].lost_tail = &sline[lno].lost_head;
 660                 sline[lno].flag = 0;
 661         }
 662         for (lno = 0, cp = result; cp < result + result_size; cp++) {
 663                 if (*cp == '\n') {
 664                         sline[lno].len = cp - sline[lno].bol;
 665                         lno++;
 666                         if (lno < cnt)
 667                                 sline[lno].bol = cp + 1;
 668                 }
 669         }
 670         if (result_size && result[result_size-1] != '\n')
 671                 sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
 672
 673         result_file.ptr = result;
 674         result_file.size = result_size;
 675
 676         /* Even p_lno[cnt+1] is valid -- that is for the end line number
 677          * for deletion hunk at the end.
 678          */
 679         sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
 680         for (lno = 0; lno <= cnt; lno++)
 681                 sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
 682
 683         for (i = 0; i < num_parent; i++) {
 684                 int j;
 685                 for (j = 0; j < i; j++) {
 686                         if (!memcmp(elem->parent[i].sha1,
 687                                     elem->parent[j].sha1, 20)) {
 688                                 reuse_combine_diff(sline, cnt, i, j);
 689                                 break;
 690                         }
 691                 }
 692                 if (i <= j)
 693                         combine_diff(elem->parent[i].sha1, &result_file, sline,
 694                                      cnt, i, num_parent);
 695                 if (elem->parent[i].mode != elem->mode)
 696                         mode_differs = 1;
 697         }
 698
 699         show_hunks = make_hunks(sline, cnt, num_parent, dense);
 700
 701         if (show_hunks || mode_differs || working_tree_file) {
 702                 const char *abb;
 703
 704                 if (rev->loginfo)
 705                         show_log(rev, opt->msg_sep);
 706                 dump_quoted_path(dense ? "diff --cc " : "diff --combined ", elem->path);
 707                 printf("index ");
 708                 for (i = 0; i < num_parent; i++) {
 709                         abb = find_unique_abbrev(elem->parent[i].sha1,
 710                                                  abbrev);
 711                         printf("%s%s", i ? "," : "", abb);
 712                 }
 713                 abb = find_unique_abbrev(elem->sha1, abbrev);
 714                 printf("..%s\n", abb);
 715
 716                 if (mode_differs) {
 717                         int added = !!elem->mode;
 718                         for (i = 0; added && i < num_parent; i++)
 719                                 if (elem->parent[i].status !=
 720                                     DIFF_STATUS_ADDED)
 721                                         added = 0;
 722                         if (added)
 723                                 printf("new file mode %06o", elem->mode);
 724                         else {
 725                                 if (!elem->mode)
 726                                         printf("deleted file ");
 727                                 printf("mode ");
 728                                 for (i = 0; i < num_parent; i++) {
 729                                         printf("%s%06o", i ? "," : "",
 730                                                elem->parent[i].mode);
 731                                 }
 732                                 if (elem->mode)
 733                                         printf("..%06o", elem->mode);
 734                         }
 735                         putchar('\n');
 736                 }
 737                 dump_quoted_path("--- a/", elem->path);
 738                 dump_quoted_path("+++ b/", elem->path);
 739                 dump_sline(sline, cnt, num_parent);
 740         }
 741         free(result);
 742
 743         for (lno = 0; lno < cnt; lno++) {
 744                 if (sline[lno].lost_head) {
 745                         struct lline *ll = sline[lno].lost_head;
 746                         while (ll) {
 747                                 struct lline *tmp = ll;
 748                                 ll = ll->next;
 749                                 free(tmp);
 750                         }
 751                 }
 752         }
 753         free(sline[0].p_lno);
 754         free(sline);
 755         return shown_header;
 756 }
 757
 758 #define COLONS "::::::::::::::::::::::::::::::::"
 759
 760 static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
 761 {
 762         struct diff_options *opt = &rev->diffopt;
 763         int i, offset;
 764         const char *prefix;
 765         int line_termination, inter_name_termination;
 766
 767         line_termination = opt->line_termination;
 768         inter_name_termination = '\t';
 769         if (!line_termination)
 770                 inter_name_termination = 0;
 771
 772         if (rev->loginfo)
 773                 show_log(rev, opt->msg_sep);
 774
 775         if (opt->output_format & DIFF_FORMAT_RAW) {
 776                 offset = strlen(COLONS) - num_parent;
 777                 if (offset < 0)
 778                         offset = 0;
 779                 prefix = COLONS + offset;
 780
 781                 /* Show the modes */
 782                 for (i = 0; i < num_parent; i++) {
 783                         printf("%s%06o", prefix, p->parent[i].mode);
 784                         prefix = " ";
 785                 }
 786                 printf("%s%06o", prefix, p->mode);
 787
 788                 /* Show sha1's */
 789                 for (i = 0; i < num_parent; i++)
 790                         printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
 791                                                          opt->abbrev));
 792                 printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
 793         }
 794
 795         if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
 796                 for (i = 0; i < num_parent; i++)
 797                         putchar(p->parent[i].status);
 798                 putchar(inter_name_termination);
 799         }
 800
 801         if (line_termination) {
 802                 if (quote_c_style(p->path, NULL, NULL, 0))
 803                         quote_c_style(p->path, NULL, stdout, 0);
 804                 else
 805                         printf("%s", p->path);
 806                 putchar(line_termination);
 807         }
 808         else {
 809                 printf("%s%c", p->path, line_termination);
 810         }
 811 }
 812
 813 void show_combined_diff(struct combine_diff_path *p,
 814                        int num_parent,
 815                        int dense,
 816                        struct rev_info *rev)
 817 {
 818         struct diff_options *opt = &rev->diffopt;
 819         if (!p->len)
 820                 return;
 821         if (opt->output_format & (DIFF_FORMAT_RAW |
 822                                   DIFF_FORMAT_NAME |
 823                                   DIFF_FORMAT_NAME_STATUS)) {
 824                 show_raw_diff(p, num_parent, rev);
 825         } else if (opt->output_format & DIFF_FORMAT_PATCH) {
 826                 show_patch_diff(p, num_parent, dense, rev);
 827         }
 828 }
 829
 830 void diff_tree_combined(const unsigned char *sha1,
 831                         const unsigned char parent[][20],
 832                         int num_parent,
 833                         int dense,
 834                         struct rev_info *rev)
 835 {
 836         struct diff_options *opt = &rev->diffopt;
 837         struct diff_options diffopts;
 838         struct combine_diff_path *p, *paths = NULL;
 839         int i, num_paths, needsep, show_log_first;
 840
 841         diffopts = *opt;
 842         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
 843         diffopts.recursive = 1;
 844
 845         show_log_first = !!rev->loginfo;
 846         needsep = 0;
 847         /* find set of paths that everybody touches */
 848         for (i = 0; i < num_parent; i++) {
 849                 /* show stat against the first parent even
 850                  * when doing combined diff.
 851                  */
 852                 if (i == 0 && opt->output_format & DIFF_FORMAT_DIFFSTAT)
 853                         diffopts.output_format = DIFF_FORMAT_DIFFSTAT;
 854                 else
 855                         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
 856                 diff_tree_sha1(parent[i], sha1, "", &diffopts);
 857                 diffcore_std(&diffopts);
 858                 paths = intersect_paths(paths, i, num_parent);
 859
 860                 if (show_log_first && i == 0) {
 861                         show_log(rev, opt->msg_sep);
 862                         if (rev->verbose_header && opt->output_format)
 863                                 putchar(opt->line_termination);
 864                 }
 865                 diff_flush(&diffopts);
 866         }
 867
 868         /* find out surviving paths */
 869         for (num_paths = 0, p = paths; p; p = p->next) {
 870                 if (p->len)
 871                         num_paths++;
 872         }
 873         if (num_paths) {
 874                 if (opt->output_format & (DIFF_FORMAT_RAW |
 875                                           DIFF_FORMAT_NAME |
 876                                           DIFF_FORMAT_NAME_STATUS)) {
 877                         for (p = paths; p; p = p->next) {
 878                                 if (p->len)
 879                                         show_raw_diff(p, num_parent, rev);
 880                         }
 881                         needsep = 1;
 882                 }
 883                 else if (opt->output_format & DIFF_FORMAT_DIFFSTAT)
 884                         needsep = 1;
 885                 if (opt->output_format & DIFF_FORMAT_PATCH) {
 886                         if (needsep)
 887                                 putchar(opt->line_termination);
 888                         for (p = paths; p; p = p->next) {
 889                                 if (p->len)
 890                                         show_patch_diff(p, num_parent, dense,
 891                                                         rev);
 892                         }
 893                 }
 894         }
 895
 896         /* Clean things up */
 897         while (paths) {
 898                 struct combine_diff_path *tmp = paths;
 899                 paths = paths->next;
 900                 free(tmp);
 901         }
 902 }
 903
 904 void diff_tree_combined_merge(const unsigned char *sha1,
 905                              int dense, struct rev_info *rev)
 906 {
 907         int num_parent;
 908         const unsigned char (*parent)[20];
 909         struct commit *commit = lookup_commit(sha1);
 910         struct commit_list *parents;
 911
 912         /* count parents */
 913         for (parents = commit->parents, num_parent = 0;
 914              parents;
 915              parents = parents->next, num_parent++)
 916                 ; /* nothing */
 917
 918         parent = xmalloc(num_parent * sizeof(*parent));
 919         for (parents = commit->parents, num_parent = 0;
 920              parents;
 921              parents = parents->next, num_parent++)
 922                 memcpy(parent + num_parent, parents->item->object.sha1, 20);
 923         diff_tree_combined(sha1, parent, num_parent, dense, rev);
 924 }