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