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 "xdiff/xmacros.h"
   9 #include "log-tree.h"
  10 #include "refs.h"
  11 #include "userdiff.h"
  12 #include "sha1-array.h"
  13 #include "revision.h"
  14
  15 static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
  16 {
  17         struct diff_queue_struct *q = &diff_queued_diff;
  18         struct combine_diff_path *p, *pprev, *ptmp;
  19         int i, cmp;
  20
  21         if (!n) {
  22                 struct combine_diff_path *list = NULL, **tail = &list;
  23                 for (i = 0; i < q->nr; i++) {
  24                         int len;
  25                         const char *path;
  26                         if (diff_unmodified_pair(q->queue[i]))
  27                                 continue;
  28                         path = q->queue[i]->two->path;
  29                         len = strlen(path);
  30                         p = xmalloc(combine_diff_path_size(num_parent, len));
  31                         p->path = (char *) &(p->parent[num_parent]);
  32                         memcpy(p->path, path, len);
  33                         p->path[len] = 0;
  34                         p->len = len;
  35                         p->next = NULL;
  36                         memset(p->parent, 0,
  37                                sizeof(p->parent[0]) * num_parent);
  38
  39                         hashcpy(p->sha1, q->queue[i]->two->sha1);
  40                         p->mode = q->queue[i]->two->mode;
  41                         hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
  42                         p->parent[n].mode = q->queue[i]->one->mode;
  43                         p->parent[n].status = q->queue[i]->status;
  44                         *tail = p;
  45                         tail = &p->next;
  46                 }
  47                 return list;
  48         }
  49
  50         /*
  51          * NOTE paths are coming sorted here (= in tree order)
  52          */
  53
  54         pprev = NULL;
  55         p = curr;
  56         i = 0;
  57
  58         while (1) {
  59                 if (!p)
  60                         break;
  61
  62                 cmp = (i >= q->nr) ? -1
  63                                    : strcmp(p->path, q->queue[i]->two->path);
  64                 if (cmp < 0) {
  65                         if (pprev)
  66                                 pprev->next = p->next;
  67                         ptmp = p;
  68                         p = p->next;
  69                         free(ptmp);
  70                         if (curr == ptmp)
  71                                 curr = p;
  72                         continue;
  73                 }
  74
  75                 if (cmp > 0) {
  76                         i++;
  77                         continue;
  78                 }
  79
  80                 hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
  81                 p->parent[n].mode = q->queue[i]->one->mode;
  82                 p->parent[n].status = q->queue[i]->status;
  83
  84                 pprev = p;
  85                 p = p->next;
  86                 i++;
  87         }
  88         return curr;
  89 }
  90
  91 /* Lines lost from parent */
  92 struct lline {
  93         struct lline *next, *prev;
  94         int len;
  95         unsigned long parent_map;
  96         char line[FLEX_ARRAY];
  97 };
  98
  99 /* Lines lost from current parent (before coalescing) */
 100 struct plost {
 101         struct lline *lost_head, *lost_tail;
 102         int len;
 103 };
 104
 105 /* Lines surviving in the merge result */
 106 struct sline {
 107         /* Accumulated and coalesced lost lines */
 108         struct lline *lost;
 109         int lenlost;
 110         struct plost plost;
 111         char *bol;
 112         int len;
 113         /* bit 0 up to (N-1) are on if the parent has this line (i.e.
 114          * we did not change it).
 115          * bit N is used for "interesting" lines, including context.
 116          * bit (N+1) is used for "do not show deletion before this".
 117          */
 118         unsigned long flag;
 119         unsigned long *p_lno;
 120 };
 121
 122 static int match_string_spaces(const char *line1, int len1,
 123                                const char *line2, int len2,
 124                                long flags)
 125 {
 126         if (flags & XDF_WHITESPACE_FLAGS) {
 127                 for (; len1 > 0 && XDL_ISSPACE(line1[len1 - 1]); len1--);
 128                 for (; len2 > 0 && XDL_ISSPACE(line2[len2 - 1]); len2--);
 129         }
 130
 131         if (!(flags & (XDF_IGNORE_WHITESPACE | XDF_IGNORE_WHITESPACE_CHANGE)))
 132                 return (len1 == len2 && !memcmp(line1, line2, len1));
 133
 134         while (len1 > 0 && len2 > 0) {
 135                 len1--;
 136                 len2--;
 137                 if (XDL_ISSPACE(line1[len1]) || XDL_ISSPACE(line2[len2])) {
 138                         if ((flags & XDF_IGNORE_WHITESPACE_CHANGE) &&
 139                             (!XDL_ISSPACE(line1[len1]) || !XDL_ISSPACE(line2[len2])))
 140                                 return 0;
 141
 142                         for (; len1 > 0 && XDL_ISSPACE(line1[len1]); len1--);
 143                         for (; len2 > 0 && XDL_ISSPACE(line2[len2]); len2--);
 144                 }
 145                 if (line1[len1] != line2[len2])
 146                         return 0;
 147         }
 148
 149         if (flags & XDF_IGNORE_WHITESPACE) {
 150                 /* Consume remaining spaces */
 151                 for (; len1 > 0 && XDL_ISSPACE(line1[len1 - 1]); len1--);
 152                 for (; len2 > 0 && XDL_ISSPACE(line2[len2 - 1]); len2--);
 153         }
 154
 155         /* We matched full line1 and line2 */
 156         if (!len1 && !len2)
 157                 return 1;
 158
 159         return 0;
 160 }
 161
 162 enum coalesce_direction { MATCH, BASE, NEW };
 163
 164 /* Coalesce new lines into base by finding LCS */
 165 static struct lline *coalesce_lines(struct lline *base, int *lenbase,
 166                                     struct lline *new, int lennew,
 167                                     unsigned long parent, long flags)
 168 {
 169         int **lcs;
 170         enum coalesce_direction **directions;
 171         struct lline *baseend, *newend = NULL;
 172         int i, j, origbaselen = *lenbase;
 173
 174         if (new == NULL)
 175                 return base;
 176
 177         if (base == NULL) {
 178                 *lenbase = lennew;
 179                 return new;
 180         }
 181
 182         /*
 183          * Coalesce new lines into base by finding the LCS
 184          * - Create the table to run dynamic programming
 185          * - Compute the LCS
 186          * - Then reverse read the direction structure:
 187          *   - If we have MATCH, assign parent to base flag, and consume
 188          *   both baseend and newend
 189          *   - Else if we have BASE, consume baseend
 190          *   - Else if we have NEW, insert newend lline into base and
 191          *   consume newend
 192          */
 193         lcs = xcalloc(origbaselen + 1, sizeof(int*));
 194         directions = xcalloc(origbaselen + 1, sizeof(enum coalesce_direction*));
 195         for (i = 0; i < origbaselen + 1; i++) {
 196                 lcs[i] = xcalloc(lennew + 1, sizeof(int));
 197                 directions[i] = xcalloc(lennew + 1, sizeof(enum coalesce_direction));
 198                 directions[i][0] = BASE;
 199         }
 200         for (j = 1; j < lennew + 1; j++)
 201                 directions[0][j] = NEW;
 202
 203         for (i = 1, baseend = base; i < origbaselen + 1; i++) {
 204                 for (j = 1, newend = new; j < lennew + 1; j++) {
 205                         if (match_string_spaces(baseend->line, baseend->len,
 206                                                 newend->line, newend->len, flags)) {
 207                                 lcs[i][j] = lcs[i - 1][j - 1] + 1;
 208                                 directions[i][j] = MATCH;
 209                         } else if (lcs[i][j - 1] >= lcs[i - 1][j]) {
 210                                 lcs[i][j] = lcs[i][j - 1];
 211                                 directions[i][j] = NEW;
 212                         } else {
 213                                 lcs[i][j] = lcs[i - 1][j];
 214                                 directions[i][j] = BASE;
 215                         }
 216                         if (newend->next)
 217                                 newend = newend->next;
 218                 }
 219                 if (baseend->next)
 220                         baseend = baseend->next;
 221         }
 222
 223         for (i = 0; i < origbaselen + 1; i++)
 224                 free(lcs[i]);
 225         free(lcs);
 226
 227         /* At this point, baseend and newend point to the end of each lists */
 228         i--;
 229         j--;
 230         while (i != 0 || j != 0) {
 231                 if (directions[i][j] == MATCH) {
 232                         baseend->parent_map |= 1<<parent;
 233                         baseend = baseend->prev;
 234                         newend = newend->prev;
 235                         i--;
 236                         j--;
 237                 } else if (directions[i][j] == NEW) {
 238                         struct lline *lline;
 239
 240                         lline = newend;
 241                         /* Remove lline from new list and update newend */
 242                         if (lline->prev)
 243                                 lline->prev->next = lline->next;
 244                         else
 245                                 new = lline->next;
 246                         if (lline->next)
 247                                 lline->next->prev = lline->prev;
 248
 249                         newend = lline->prev;
 250                         j--;
 251
 252                         /* Add lline to base list */
 253                         if (baseend) {
 254                                 lline->next = baseend->next;
 255                                 lline->prev = baseend;
 256                                 if (lline->prev)
 257                                         lline->prev->next = lline;
 258                         }
 259                         else {
 260                                 lline->next = base;
 261                                 base = lline;
 262                         }
 263                         (*lenbase)++;
 264
 265                         if (lline->next)
 266                                 lline->next->prev = lline;
 267
 268                 } else {
 269                         baseend = baseend->prev;
 270                         i--;
 271                 }
 272         }
 273
 274         newend = new;
 275         while (newend) {
 276                 struct lline *lline = newend;
 277                 newend = newend->next;
 278                 free(lline);
 279         }
 280
 281         for (i = 0; i < origbaselen + 1; i++)
 282                 free(directions[i]);
 283         free(directions);
 284
 285         return base;
 286 }
 287
 288 static char *grab_blob(const unsigned char *sha1, unsigned int mode,
 289                        unsigned long *size, struct userdiff_driver *textconv,
 290                        const char *path)
 291 {
 292         char *blob;
 293         enum object_type type;
 294
 295         if (S_ISGITLINK(mode)) {
 296                 blob = xmalloc(100);
 297                 *size = snprintf(blob, 100,
 298                                  "Subproject commit %s\n", sha1_to_hex(sha1));
 299         } else if (is_null_sha1(sha1)) {
 300                 /* deleted blob */
 301                 *size = 0;
 302                 return xcalloc(1, 1);
 303         } else if (textconv) {
 304                 struct diff_filespec *df = alloc_filespec(path);
 305                 fill_filespec(df, sha1, 1, mode);
 306                 *size = fill_textconv(textconv, df, &blob);
 307                 free_filespec(df);
 308         } else {
 309                 blob = read_sha1_file(sha1, &type, size);
 310                 if (type != OBJ_BLOB)
 311                         die("object '%s' is not a blob!", sha1_to_hex(sha1));
 312         }
 313         return blob;
 314 }
 315
 316 static void append_lost(struct sline *sline, int n, const char *line, int len)
 317 {
 318         struct lline *lline;
 319         unsigned long this_mask = (1UL<<n);
 320         if (line[len-1] == '\n')
 321                 len--;
 322
 323         lline = xmalloc(sizeof(*lline) + len + 1);
 324         lline->len = len;
 325         lline->next = NULL;
 326         lline->prev = sline->plost.lost_tail;
 327         if (lline->prev)
 328                 lline->prev->next = lline;
 329         else
 330                 sline->plost.lost_head = lline;
 331         sline->plost.lost_tail = lline;
 332         sline->plost.len++;
 333         lline->parent_map = this_mask;
 334         memcpy(lline->line, line, len);
 335         lline->line[len] = 0;
 336 }
 337
 338 struct combine_diff_state {
 339         unsigned int lno;
 340         int ob, on, nb, nn;
 341         unsigned long nmask;
 342         int num_parent;
 343         int n;
 344         struct sline *sline;
 345         struct sline *lost_bucket;
 346 };
 347
 348 static void consume_line(void *state_, char *line, unsigned long len)
 349 {
 350         struct combine_diff_state *state = state_;
 351         if (5 < len && !memcmp("@@ -", line, 4)) {
 352                 if (parse_hunk_header(line, len,
 353                                       &state->ob, &state->on,
 354                                       &state->nb, &state->nn))
 355                         return;
 356                 state->lno = state->nb;
 357                 if (state->nn == 0) {
 358                         /* @@ -X,Y +N,0 @@ removed Y lines
 359                          * that would have come *after* line N
 360                          * in the result.  Our lost buckets hang
 361                          * to the line after the removed lines,
 362                          *
 363                          * Note that this is correct even when N == 0,
 364                          * in which case the hunk removes the first
 365                          * line in the file.
 366                          */
 367                         state->lost_bucket = &state->sline[state->nb];
 368                         if (!state->nb)
 369                                 state->nb = 1;
 370                 } else {
 371                         state->lost_bucket = &state->sline[state->nb-1];
 372                 }
 373                 if (!state->sline[state->nb-1].p_lno)
 374                         state->sline[state->nb-1].p_lno =
 375                                 xcalloc(state->num_parent,
 376                                         sizeof(unsigned long));
 377                 state->sline[state->nb-1].p_lno[state->n] = state->ob;
 378                 return;
 379         }
 380         if (!state->lost_bucket)
 381                 return; /* not in any hunk yet */
 382         switch (line[0]) {
 383         case '-':
 384                 append_lost(state->lost_bucket, state->n, line+1, len-1);
 385                 break;
 386         case '+':
 387                 state->sline[state->lno-1].flag |= state->nmask;
 388                 state->lno++;
 389                 break;
 390         }
 391 }
 392
 393 static void combine_diff(const unsigned char *parent, unsigned int mode,
 394                          mmfile_t *result_file,
 395                          struct sline *sline, unsigned int cnt, int n,
 396                          int num_parent, int result_deleted,
 397                          struct userdiff_driver *textconv,
 398                          const char *path, long flags)
 399 {
 400         unsigned int p_lno, lno;
 401         unsigned long nmask = (1UL << n);
 402         xpparam_t xpp;
 403         xdemitconf_t xecfg;
 404         mmfile_t parent_file;
 405         struct combine_diff_state state;
 406         unsigned long sz;
 407
 408         if (result_deleted)
 409                 return; /* result deleted */
 410
 411         parent_file.ptr = grab_blob(parent, mode, &sz, textconv, path);
 412         parent_file.size = sz;
 413         memset(&xpp, 0, sizeof(xpp));
 414         xpp.flags = flags;
 415         memset(&xecfg, 0, sizeof(xecfg));
 416         memset(&state, 0, sizeof(state));
 417         state.nmask = nmask;
 418         state.sline = sline;
 419         state.lno = 1;
 420         state.num_parent = num_parent;
 421         state.n = n;
 422
 423         xdi_diff_outf(&parent_file, result_file, consume_line, &state,
 424                       &xpp, &xecfg);
 425         free(parent_file.ptr);
 426
 427         /* Assign line numbers for this parent.
 428          *
 429          * sline[lno].p_lno[n] records the first line number
 430          * (counting from 1) for parent N if the final hunk display
 431          * started by showing sline[lno] (possibly showing the lost
 432          * lines attached to it first).
 433          */
 434         for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
 435                 struct lline *ll;
 436                 sline[lno].p_lno[n] = p_lno;
 437
 438                 /* Coalesce new lines */
 439                 if (sline[lno].plost.lost_head) {
 440                         struct sline *sl = &sline[lno];
 441                         sl->lost = coalesce_lines(sl->lost, &sl->lenlost,
 442                                                   sl->plost.lost_head,
 443                                                   sl->plost.len, n, flags);
 444                         sl->plost.lost_head = sl->plost.lost_tail = NULL;
 445                         sl->plost.len = 0;
 446                 }
 447
 448                 /* How many lines would this sline advance the p_lno? */
 449                 ll = sline[lno].lost;
 450                 while (ll) {
 451                         if (ll->parent_map & nmask)
 452                                 p_lno++; /* '-' means parent had it */
 453                         ll = ll->next;
 454                 }
 455                 if (lno < cnt && !(sline[lno].flag & nmask))
 456                         p_lno++; /* no '+' means parent had it */
 457         }
 458         sline[lno].p_lno[n] = p_lno; /* trailer */
 459 }
 460
 461 static unsigned long context = 3;
 462 static char combine_marker = '@';
 463
 464 static int interesting(struct sline *sline, unsigned long all_mask)
 465 {
 466         /* If some parents lost lines here, or if we have added to
 467          * some parent, it is interesting.
 468          */
 469         return ((sline->flag & all_mask) || sline->lost);
 470 }
 471
 472 static unsigned long adjust_hunk_tail(struct sline *sline,
 473                                       unsigned long all_mask,
 474                                       unsigned long hunk_begin,
 475                                       unsigned long i)
 476 {
 477         /* i points at the first uninteresting line.  If the last line
 478          * of the hunk was interesting only because it has some
 479          * deletion, then it is not all that interesting for the
 480          * purpose of giving trailing context lines.  This is because
 481          * we output '-' line and then unmodified sline[i-1] itself in
 482          * that case which gives us one extra context line.
 483          */
 484         if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
 485                 i--;
 486         return i;
 487 }
 488
 489 static unsigned long find_next(struct sline *sline,
 490                                unsigned long mark,
 491                                unsigned long i,
 492                                unsigned long cnt,
 493                                int look_for_uninteresting)
 494 {
 495         /* We have examined up to i-1 and are about to look at i.
 496          * Find next interesting or uninteresting line.  Here,
 497          * "interesting" does not mean interesting(), but marked by
 498          * the give_context() function below (i.e. it includes context
 499          * lines that are not interesting to interesting() function
 500          * that are surrounded by interesting() ones.
 501          */
 502         while (i <= cnt)
 503                 if (look_for_uninteresting
 504                     ? !(sline[i].flag & mark)
 505                     : (sline[i].flag & mark))
 506                         return i;
 507                 else
 508                         i++;
 509         return i;
 510 }
 511
 512 static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 513 {
 514         unsigned long all_mask = (1UL<<num_parent) - 1;
 515         unsigned long mark = (1UL<<num_parent);
 516         unsigned long no_pre_delete = (2UL<<num_parent);
 517         unsigned long i;
 518
 519         /* Two groups of interesting lines may have a short gap of
 520          * uninteresting lines.  Connect such groups to give them a
 521          * bit of context.
 522          *
 523          * We first start from what the interesting() function says,
 524          * and mark them with "mark", and paint context lines with the
 525          * mark.  So interesting() would still say false for such context
 526          * lines but they are treated as "interesting" in the end.
 527          */
 528         i = find_next(sline, mark, 0, cnt, 0);
 529         if (cnt < i)
 530                 return 0;
 531
 532         while (i <= cnt) {
 533                 unsigned long j = (context < i) ? (i - context) : 0;
 534                 unsigned long k;
 535
 536                 /* Paint a few lines before the first interesting line. */
 537                 while (j < i) {
 538                         if (!(sline[j].flag & mark))
 539                                 sline[j].flag |= no_pre_delete;
 540                         sline[j++].flag |= mark;
 541                 }
 542
 543         again:
 544                 /* we know up to i is to be included.  where does the
 545                  * next uninteresting one start?
 546                  */
 547                 j = find_next(sline, mark, i, cnt, 1);
 548                 if (cnt < j)
 549                         break; /* the rest are all interesting */
 550
 551                 /* lookahead context lines */
 552                 k = find_next(sline, mark, j, cnt, 0);
 553                 j = adjust_hunk_tail(sline, all_mask, i, j);
 554
 555                 if (k < j + context) {
 556                         /* k is interesting and [j,k) are not, but
 557                          * paint them interesting because the gap is small.
 558                          */
 559                         while (j < k)
 560                                 sline[j++].flag |= mark;
 561                         i = k;
 562                         goto again;
 563                 }
 564
 565                 /* j is the first uninteresting line and there is
 566                  * no overlap beyond it within context lines.  Paint
 567                  * the trailing edge a bit.
 568                  */
 569                 i = k;
 570                 k = (j + context < cnt+1) ? j + context : cnt+1;
 571                 while (j < k)
 572                         sline[j++].flag |= mark;
 573         }
 574         return 1;
 575 }
 576
 577 static int make_hunks(struct sline *sline, unsigned long cnt,
 578                        int num_parent, int dense)
 579 {
 580         unsigned long all_mask = (1UL<<num_parent) - 1;
 581         unsigned long mark = (1UL<<num_parent);
 582         unsigned long i;
 583         int has_interesting = 0;
 584
 585         for (i = 0; i <= cnt; i++) {
 586                 if (interesting(&sline[i], all_mask))
 587                         sline[i].flag |= mark;
 588                 else
 589                         sline[i].flag &= ~mark;
 590         }
 591         if (!dense)
 592                 return give_context(sline, cnt, num_parent);
 593
 594         /* Look at each hunk, and if we have changes from only one
 595          * parent, or the changes are the same from all but one
 596          * parent, mark that uninteresting.
 597          */
 598         i = 0;
 599         while (i <= cnt) {
 600                 unsigned long j, hunk_begin, hunk_end;
 601                 unsigned long same_diff;
 602                 while (i <= cnt && !(sline[i].flag & mark))
 603                         i++;
 604                 if (cnt < i)
 605                         break; /* No more interesting hunks */
 606                 hunk_begin = i;
 607                 for (j = i + 1; j <= cnt; j++) {
 608                         if (!(sline[j].flag & mark)) {
 609                                 /* Look beyond the end to see if there
 610                                  * is an interesting line after this
 611                                  * hunk within context span.
 612                                  */
 613                                 unsigned long la; /* lookahead */
 614                                 int contin = 0;
 615                                 la = adjust_hunk_tail(sline, all_mask,
 616                                                      hunk_begin, j);
 617                                 la = (la + context < cnt + 1) ?
 618                                         (la + context) : cnt + 1;
 619                                 while (la && j <= --la) {
 620                                         if (sline[la].flag & mark) {
 621                                                 contin = 1;
 622                                                 break;
 623                                         }
 624                                 }
 625                                 if (!contin)
 626                                         break;
 627                                 j = la;
 628                         }
 629                 }
 630                 hunk_end = j;
 631
 632                 /* [i..hunk_end) are interesting.  Now is it really
 633                  * interesting?  We check if there are only two versions
 634                  * and the result matches one of them.  That is, we look
 635                  * at:
 636                  *   (+) line, which records lines added to which parents;
 637                  *       this line appears in the result.
 638                  *   (-) line, which records from what parents the line
 639                  *       was removed; this line does not appear in the result.
 640                  * then check the set of parents the result has difference
 641                  * from, from all lines.  If there are lines that has
 642                  * different set of parents that the result has differences
 643                  * from, that means we have more than two versions.
 644                  *
 645                  * Even when we have only two versions, if the result does
 646                  * not match any of the parents, the it should be considered
 647                  * interesting.  In such a case, we would have all '+' line.
 648                  * After passing the above "two versions" test, that would
 649                  * appear as "the same set of parents" to be "all parents".
 650                  */
 651                 same_diff = 0;
 652                 has_interesting = 0;
 653                 for (j = i; j < hunk_end && !has_interesting; j++) {
 654                         unsigned long this_diff = sline[j].flag & all_mask;
 655                         struct lline *ll = sline[j].lost;
 656                         if (this_diff) {
 657                                 /* This has some changes.  Is it the
 658                                  * same as others?
 659                                  */
 660                                 if (!same_diff)
 661                                         same_diff = this_diff;
 662                                 else if (same_diff != this_diff) {
 663                                         has_interesting = 1;
 664                                         break;
 665                                 }
 666                         }
 667                         while (ll && !has_interesting) {
 668                                 /* Lost this line from these parents;
 669                                  * who are they?  Are they the same?
 670                                  */
 671                                 this_diff = ll->parent_map;
 672                                 if (!same_diff)
 673                                         same_diff = this_diff;
 674                                 else if (same_diff != this_diff) {
 675                                         has_interesting = 1;
 676                                 }
 677                                 ll = ll->next;
 678                         }
 679                 }
 680
 681                 if (!has_interesting && same_diff != all_mask) {
 682                         /* This hunk is not that interesting after all */
 683                         for (j = hunk_begin; j < hunk_end; j++)
 684                                 sline[j].flag &= ~mark;
 685                 }
 686                 i = hunk_end;
 687         }
 688
 689         has_interesting = give_context(sline, cnt, num_parent);
 690         return has_interesting;
 691 }
 692
 693 static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
 694 {
 695         l0 = sline[l0].p_lno[n];
 696         l1 = sline[l1].p_lno[n];
 697         printf(" -%lu,%lu", l0, l1-l0-null_context);
 698 }
 699
 700 static int hunk_comment_line(const char *bol)
 701 {
 702         int ch;
 703
 704         if (!bol)
 705                 return 0;
 706         ch = *bol & 0xff;
 707         return (isalpha(ch) || ch == '_' || ch == '$');
 708 }
 709
 710 static void show_line_to_eol(const char *line, int len, const char *reset)
 711 {
 712         int saw_cr_at_eol = 0;
 713         if (len < 0)
 714                 len = strlen(line);
 715         saw_cr_at_eol = (len && line[len-1] == '\r');
 716
 717         printf("%.*s%s%s\n", len - saw_cr_at_eol, line,
 718                reset,
 719                saw_cr_at_eol ? "\r" : "");
 720 }
 721
 722 static void dump_sline(struct sline *sline, const char *line_prefix,
 723                        unsigned long cnt, int num_parent,
 724                        int use_color, int result_deleted)
 725 {
 726         unsigned long mark = (1UL<<num_parent);
 727         unsigned long no_pre_delete = (2UL<<num_parent);
 728         int i;
 729         unsigned long lno = 0;
 730         const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
 731         const char *c_func = diff_get_color(use_color, DIFF_FUNCINFO);
 732         const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
 733         const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
 734         const char *c_plain = diff_get_color(use_color, DIFF_PLAIN);
 735         const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 736
 737         if (result_deleted)
 738                 return; /* result deleted */
 739
 740         while (1) {
 741                 unsigned long hunk_end;
 742                 unsigned long rlines;
 743                 const char *hunk_comment = NULL;
 744                 unsigned long null_context = 0;
 745
 746                 while (lno <= cnt && !(sline[lno].flag & mark)) {
 747                         if (hunk_comment_line(sline[lno].bol))
 748                                 hunk_comment = sline[lno].bol;
 749                         lno++;
 750                 }
 751                 if (cnt < lno)
 752                         break;
 753                 else {
 754                         for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
 755                                 if (!(sline[hunk_end].flag & mark))
 756                                         break;
 757                 }
 758                 rlines = hunk_end - lno;
 759                 if (cnt < hunk_end)
 760                         rlines--; /* pointing at the last delete hunk */
 761
 762                 if (!context) {
 763                         /*
 764                          * Even when running with --unified=0, all
 765                          * lines in the hunk needs to be processed in
 766                          * the loop below in order to show the
 767                          * deletion recorded in lost_head.  However,
 768                          * we do not want to show the resulting line
 769                          * with all blank context markers in such a
 770                          * case.  Compensate.
 771                          */
 772                         unsigned long j;
 773                         for (j = lno; j < hunk_end; j++)
 774                                 if (!(sline[j].flag & (mark-1)))
 775                                         null_context++;
 776                         rlines -= null_context;
 777                 }
 778
 779                 printf("%s%s", line_prefix, c_frag);
 780                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 781                 for (i = 0; i < num_parent; i++)
 782                         show_parent_lno(sline, lno, hunk_end, i, null_context);
 783                 printf(" +%lu,%lu ", lno+1, rlines);
 784                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 785
 786                 if (hunk_comment) {
 787                         int comment_end = 0;
 788                         for (i = 0; i < 40; i++) {
 789                                 int ch = hunk_comment[i] & 0xff;
 790                                 if (!ch || ch == '\n')
 791                                         break;
 792                                 if (!isspace(ch))
 793                                     comment_end = i;
 794                         }
 795                         if (comment_end)
 796                                 printf("%s%s %s%s", c_reset,
 797                                                     c_plain, c_reset,
 798                                                     c_func);
 799                         for (i = 0; i < comment_end; i++)
 800                                 putchar(hunk_comment[i]);
 801                 }
 802
 803                 printf("%s\n", c_reset);
 804                 while (lno < hunk_end) {
 805                         struct lline *ll;
 806                         int j;
 807                         unsigned long p_mask;
 808                         struct sline *sl = &sline[lno++];
 809                         ll = (sl->flag & no_pre_delete) ? NULL : sl->lost;
 810                         while (ll) {
 811                                 printf("%s%s", line_prefix, c_old);
 812                                 for (j = 0; j < num_parent; j++) {
 813                                         if (ll->parent_map & (1UL<<j))
 814                                                 putchar('-');
 815                                         else
 816                                                 putchar(' ');
 817                                 }
 818                                 show_line_to_eol(ll->line, -1, c_reset);
 819                                 ll = ll->next;
 820                         }
 821                         if (cnt < lno)
 822                                 break;
 823                         p_mask = 1;
 824                         fputs(line_prefix, stdout);
 825                         if (!(sl->flag & (mark-1))) {
 826                                 /*
 827                                  * This sline was here to hang the
 828                                  * lost lines in front of it.
 829                                  */
 830                                 if (!context)
 831                                         continue;
 832                                 fputs(c_plain, stdout);
 833                         }
 834                         else
 835                                 fputs(c_new, stdout);
 836                         for (j = 0; j < num_parent; j++) {
 837                                 if (p_mask & sl->flag)
 838                                         putchar('+');
 839                                 else
 840                                         putchar(' ');
 841                                 p_mask <<= 1;
 842                         }
 843                         show_line_to_eol(sl->bol, sl->len, c_reset);
 844                 }
 845         }
 846 }
 847
 848 static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 849                                int i, int j)
 850 {
 851         /* We have already examined parent j and we know parent i
 852          * and parent j are the same, so reuse the combined result
 853          * of parent j for parent i.
 854          */
 855         unsigned long lno, imask, jmask;
 856         imask = (1UL<<i);
 857         jmask = (1UL<<j);
 858
 859         for (lno = 0; lno <= cnt; lno++) {
 860                 struct lline *ll = sline->lost;
 861                 sline->p_lno[i] = sline->p_lno[j];
 862                 while (ll) {
 863                         if (ll->parent_map & jmask)
 864                                 ll->parent_map |= imask;
 865                         ll = ll->next;
 866                 }
 867                 if (sline->flag & jmask)
 868                         sline->flag |= imask;
 869                 sline++;
 870         }
 871         /* the overall size of the file (sline[cnt]) */
 872         sline->p_lno[i] = sline->p_lno[j];
 873 }
 874
 875 static void dump_quoted_path(const char *head,
 876                              const char *prefix,
 877                              const char *path,
 878                              const char *line_prefix,
 879                              const char *c_meta, const char *c_reset)
 880 {
 881         static struct strbuf buf = STRBUF_INIT;
 882
 883         strbuf_reset(&buf);
 884         strbuf_addstr(&buf, line_prefix);
 885         strbuf_addstr(&buf, c_meta);
 886         strbuf_addstr(&buf, head);
 887         quote_two_c_style(&buf, prefix, path, 0);
 888         strbuf_addstr(&buf, c_reset);
 889         puts(buf.buf);
 890 }
 891
 892 static void show_combined_header(struct combine_diff_path *elem,
 893                                  int num_parent,
 894                                  int dense,
 895                                  struct rev_info *rev,
 896                                  const char *line_prefix,
 897                                  int mode_differs,
 898                                  int show_file_header)
 899 {
 900         struct diff_options *opt = &rev->diffopt;
 901         int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
 902         const char *a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
 903         const char *b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
 904         const char *c_meta = diff_get_color_opt(opt, DIFF_METAINFO);
 905         const char *c_reset = diff_get_color_opt(opt, DIFF_RESET);
 906         const char *abb;
 907         int added = 0;
 908         int deleted = 0;
 909         int i;
 910
 911         if (rev->loginfo && !rev->no_commit_id)
 912                 show_log(rev);
 913
 914         dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
 915                          "", elem->path, line_prefix, c_meta, c_reset);
 916         printf("%s%sindex ", line_prefix, c_meta);
 917         for (i = 0; i < num_parent; i++) {
 918                 abb = find_unique_abbrev(elem->parent[i].sha1,
 919                                          abbrev);
 920                 printf("%s%s", i ? "," : "", abb);
 921         }
 922         abb = find_unique_abbrev(elem->sha1, abbrev);
 923         printf("..%s%s\n", abb, c_reset);
 924
 925         if (mode_differs) {
 926                 deleted = !elem->mode;
 927
 928                 /* We say it was added if nobody had it */
 929                 added = !deleted;
 930                 for (i = 0; added && i < num_parent; i++)
 931                         if (elem->parent[i].status !=
 932                             DIFF_STATUS_ADDED)
 933                                 added = 0;
 934                 if (added)
 935                         printf("%s%snew file mode %06o",
 936                                line_prefix, c_meta, elem->mode);
 937                 else {
 938                         if (deleted)
 939                                 printf("%s%sdeleted file ",
 940                                        line_prefix, c_meta);
 941                         printf("mode ");
 942                         for (i = 0; i < num_parent; i++) {
 943                                 printf("%s%06o", i ? "," : "",
 944                                        elem->parent[i].mode);
 945                         }
 946                         if (elem->mode)
 947                                 printf("..%06o", elem->mode);
 948                 }
 949                 printf("%s\n", c_reset);
 950         }
 951
 952         if (!show_file_header)
 953                 return;
 954
 955         if (added)
 956                 dump_quoted_path("--- ", "", "/dev/null",
 957                                  line_prefix, c_meta, c_reset);
 958         else
 959                 dump_quoted_path("--- ", a_prefix, elem->path,
 960                                  line_prefix, c_meta, c_reset);
 961         if (deleted)
 962                 dump_quoted_path("+++ ", "", "/dev/null",
 963                                  line_prefix, c_meta, c_reset);
 964         else
 965                 dump_quoted_path("+++ ", b_prefix, elem->path,
 966                                  line_prefix, c_meta, c_reset);
 967 }
 968
 969 static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 970                             int dense, int working_tree_file,
 971                             struct rev_info *rev)
 972 {
 973         struct diff_options *opt = &rev->diffopt;
 974         unsigned long result_size, cnt, lno;
 975         int result_deleted = 0;
 976         char *result, *cp;
 977         struct sline *sline; /* survived lines */
 978         int mode_differs = 0;
 979         int i, show_hunks;
 980         mmfile_t result_file;
 981         struct userdiff_driver *userdiff;
 982         struct userdiff_driver *textconv = NULL;
 983         int is_binary;
 984         const char *line_prefix = diff_line_prefix(opt);
 985
 986         context = opt->context;
 987         userdiff = userdiff_find_by_path(elem->path);
 988         if (!userdiff)
 989                 userdiff = userdiff_find_by_name("default");
 990         if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV))
 991                 textconv = userdiff_get_textconv(userdiff);
 992
 993         /* Read the result of merge first */
 994         if (!working_tree_file)
 995                 result = grab_blob(elem->sha1, elem->mode, &result_size,
 996                                    textconv, elem->path);
 997         else {
 998                 /* Used by diff-tree to read from the working tree */
 999                 struct stat st;
1000                 int fd = -1;
1001
1002                 if (lstat(elem->path, &st) < 0)
1003                         goto deleted_file;
1004
1005                 if (S_ISLNK(st.st_mode)) {
1006                         struct strbuf buf = STRBUF_INIT;
1007
1008                         if (strbuf_readlink(&buf, elem->path, st.st_size) < 0) {
1009                                 error("readlink(%s): %s", elem->path,
1010                                       strerror(errno));
1011                                 return;
1012                         }
1013                         result_size = buf.len;
1014                         result = strbuf_detach(&buf, NULL);
1015                         elem->mode = canon_mode(st.st_mode);
1016                 } else if (S_ISDIR(st.st_mode)) {
1017                         unsigned char sha1[20];
1018                         if (resolve_gitlink_ref(elem->path, "HEAD", sha1) < 0)
1019                                 result = grab_blob(elem->sha1, elem->mode,
1020                                                    &result_size, NULL, NULL);
1021                         else
1022                                 result = grab_blob(sha1, elem->mode,
1023                                                    &result_size, NULL, NULL);
1024                 } else if (textconv) {
1025                         struct diff_filespec *df = alloc_filespec(elem->path);
1026                         fill_filespec(df, null_sha1, 0, st.st_mode);
1027                         result_size = fill_textconv(textconv, df, &result);
1028                         free_filespec(df);
1029                 } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
1030                         size_t len = xsize_t(st.st_size);
1031                         ssize_t done;
1032                         int is_file, i;
1033
1034                         elem->mode = canon_mode(st.st_mode);
1035                         /* if symlinks don't work, assume symlink if all parents
1036                          * are symlinks
1037                          */
1038                         is_file = has_symlinks;
1039                         for (i = 0; !is_file && i < num_parent; i++)
1040                                 is_file = !S_ISLNK(elem->parent[i].mode);
1041                         if (!is_file)
1042                                 elem->mode = canon_mode(S_IFLNK);
1043
1044                         result_size = len;
1045                         result = xmalloc(len + 1);
1046
1047                         done = read_in_full(fd, result, len);
1048                         if (done < 0)
1049                                 die_errno("read error '%s'", elem->path);
1050                         else if (done < len)
1051                                 die("early EOF '%s'", elem->path);
1052
1053                         result[len] = 0;
1054
1055                         /* If not a fake symlink, apply filters, e.g. autocrlf */
1056                         if (is_file) {
1057                                 struct strbuf buf = STRBUF_INIT;
1058
1059                                 if (convert_to_git(elem->path, result, len, &buf, safe_crlf)) {
1060                                         free(result);
1061                                         result = strbuf_detach(&buf, &len);
1062                                         result_size = len;
1063                                 }
1064                         }
1065                 }
1066                 else {
1067                 deleted_file:
1068                         result_deleted = 1;
1069                         result_size = 0;
1070                         elem->mode = 0;
1071                         result = xcalloc(1, 1);
1072                 }
1073
1074                 if (0 <= fd)
1075                         close(fd);
1076         }
1077
1078         for (i = 0; i < num_parent; i++) {
1079                 if (elem->parent[i].mode != elem->mode) {
1080                         mode_differs = 1;
1081                         break;
1082                 }
1083         }
1084
1085         if (textconv)
1086                 is_binary = 0;
1087         else if (userdiff->binary != -1)
1088                 is_binary = userdiff->binary;
1089         else {
1090                 is_binary = buffer_is_binary(result, result_size);
1091                 for (i = 0; !is_binary && i < num_parent; i++) {
1092                         char *buf;
1093                         unsigned long size;
1094                         buf = grab_blob(elem->parent[i].sha1,
1095                                         elem->parent[i].mode,
1096                                         &size, NULL, NULL);
1097                         if (buffer_is_binary(buf, size))
1098                                 is_binary = 1;
1099                         free(buf);
1100                 }
1101         }
1102         if (is_binary) {
1103                 show_combined_header(elem, num_parent, dense, rev,
1104                                      line_prefix, mode_differs, 0);
1105                 printf("Binary files differ\n");
1106                 free(result);
1107                 return;
1108         }
1109
1110         for (cnt = 0, cp = result; cp < result + result_size; cp++) {
1111                 if (*cp == '\n')
1112                         cnt++;
1113         }
1114         if (result_size && result[result_size-1] != '\n')
1115                 cnt++; /* incomplete line */
1116
1117         sline = xcalloc(cnt+2, sizeof(*sline));
1118         sline[0].bol = result;
1119         for (lno = 0, cp = result; cp < result + result_size; cp++) {
1120                 if (*cp == '\n') {
1121                         sline[lno].len = cp - sline[lno].bol;
1122                         lno++;
1123                         if (lno < cnt)
1124                                 sline[lno].bol = cp + 1;
1125                 }
1126         }
1127         if (result_size && result[result_size-1] != '\n')
1128                 sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
1129
1130         result_file.ptr = result;
1131         result_file.size = result_size;
1132
1133         /* Even p_lno[cnt+1] is valid -- that is for the end line number
1134          * for deletion hunk at the end.
1135          */
1136         sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
1137         for (lno = 0; lno <= cnt; lno++)
1138                 sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
1139
1140         for (i = 0; i < num_parent; i++) {
1141                 int j;
1142                 for (j = 0; j < i; j++) {
1143                         if (!hashcmp(elem->parent[i].sha1,
1144                                      elem->parent[j].sha1)) {
1145                                 reuse_combine_diff(sline, cnt, i, j);
1146                                 break;
1147                         }
1148                 }
1149                 if (i <= j)
1150                         combine_diff(elem->parent[i].sha1,
1151                                      elem->parent[i].mode,
1152                                      &result_file, sline,
1153                                      cnt, i, num_parent, result_deleted,
1154                                      textconv, elem->path, opt->xdl_opts);
1155         }
1156
1157         show_hunks = make_hunks(sline, cnt, num_parent, dense);
1158
1159         if (show_hunks || mode_differs || working_tree_file) {
1160                 show_combined_header(elem, num_parent, dense, rev,
1161                                      line_prefix, mode_differs, 1);
1162                 dump_sline(sline, line_prefix, cnt, num_parent,
1163                            opt->use_color, result_deleted);
1164         }
1165         free(result);
1166
1167         for (lno = 0; lno < cnt; lno++) {
1168                 if (sline[lno].lost) {
1169                         struct lline *ll = sline[lno].lost;
1170                         while (ll) {
1171                                 struct lline *tmp = ll;
1172                                 ll = ll->next;
1173                                 free(tmp);
1174                         }
1175                 }
1176         }
1177         free(sline[0].p_lno);
1178         free(sline);
1179 }
1180
1181 static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
1182 {
1183         struct diff_options *opt = &rev->diffopt;
1184         int line_termination, inter_name_termination, i;
1185         const char *line_prefix = diff_line_prefix(opt);
1186
1187         line_termination = opt->line_termination;
1188         inter_name_termination = '\t';
1189         if (!line_termination)
1190                 inter_name_termination = 0;
1191
1192         if (rev->loginfo && !rev->no_commit_id)
1193                 show_log(rev);
1194
1195
1196         if (opt->output_format & DIFF_FORMAT_RAW) {
1197                 printf("%s", line_prefix);
1198
1199                 /* As many colons as there are parents */
1200                 for (i = 0; i < num_parent; i++)
1201                         putchar(':');
1202
1203                 /* Show the modes */
1204                 for (i = 0; i < num_parent; i++)
1205                         printf("%06o ", p->parent[i].mode);
1206                 printf("%06o", p->mode);
1207
1208                 /* Show sha1's */
1209                 for (i = 0; i < num_parent; i++)
1210                         printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
1211                                                          opt->abbrev));
1212                 printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
1213         }
1214
1215         if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
1216                 for (i = 0; i < num_parent; i++)
1217                         putchar(p->parent[i].status);
1218                 putchar(inter_name_termination);
1219         }
1220
1221         write_name_quoted(p->path, stdout, line_termination);
1222 }
1223
1224 /*
1225  * The result (p->elem) is from the working tree and their
1226  * parents are typically from multiple stages during a merge
1227  * (i.e. diff-files) or the state in HEAD and in the index
1228  * (i.e. diff-index).
1229  */
1230 void show_combined_diff(struct combine_diff_path *p,
1231                        int num_parent,
1232                        int dense,
1233                        struct rev_info *rev)
1234 {
1235         struct diff_options *opt = &rev->diffopt;
1236
1237         if (!p->len)
1238                 return;
1239         if (opt->output_format & (DIFF_FORMAT_RAW |
1240                                   DIFF_FORMAT_NAME |
1241                                   DIFF_FORMAT_NAME_STATUS))
1242                 show_raw_diff(p, num_parent, rev);
1243         else if (opt->output_format & DIFF_FORMAT_PATCH)
1244                 show_patch_diff(p, num_parent, dense, 1, rev);
1245 }
1246
1247 static void free_combined_pair(struct diff_filepair *pair)
1248 {
1249         free(pair->two);
1250         free(pair);
1251 }
1252
1253 /*
1254  * A combine_diff_path expresses N parents on the LHS against 1 merge
1255  * result. Synthesize a diff_filepair that has N entries on the "one"
1256  * side and 1 entry on the "two" side.
1257  *
1258  * In the future, we might want to add more data to combine_diff_path
1259  * so that we can fill fields we are ignoring (most notably, size) here,
1260  * but currently nobody uses it, so this should suffice for now.
1261  */
1262 static struct diff_filepair *combined_pair(struct combine_diff_path *p,
1263                                            int num_parent)
1264 {
1265         int i;
1266         struct diff_filepair *pair;
1267         struct diff_filespec *pool;
1268
1269         pair = xmalloc(sizeof(*pair));
1270         pool = xcalloc(num_parent + 1, sizeof(struct diff_filespec));
1271         pair->one = pool + 1;
1272         pair->two = pool;
1273
1274         for (i = 0; i < num_parent; i++) {
1275                 pair->one[i].path = p->path;
1276                 pair->one[i].mode = p->parent[i].mode;
1277                 hashcpy(pair->one[i].sha1, p->parent[i].sha1);
1278                 pair->one[i].sha1_valid = !is_null_sha1(p->parent[i].sha1);
1279                 pair->one[i].has_more_entries = 1;
1280         }
1281         pair->one[num_parent - 1].has_more_entries = 0;
1282
1283         pair->two->path = p->path;
1284         pair->two->mode = p->mode;
1285         hashcpy(pair->two->sha1, p->sha1);
1286         pair->two->sha1_valid = !is_null_sha1(p->sha1);
1287         return pair;
1288 }
1289
1290 static void handle_combined_callback(struct diff_options *opt,
1291                                      struct combine_diff_path *paths,
1292                                      int num_parent,
1293                                      int num_paths)
1294 {
1295         struct combine_diff_path *p;
1296         struct diff_queue_struct q;
1297         int i;
1298
1299         q.queue = xcalloc(num_paths, sizeof(struct diff_filepair *));
1300         q.alloc = num_paths;
1301         q.nr = num_paths;
1302         for (i = 0, p = paths; p; p = p->next) {
1303                 if (!p->len)
1304                         continue;
1305                 q.queue[i++] = combined_pair(p, num_parent);
1306         }
1307         opt->format_callback(&q, opt, opt->format_callback_data);
1308         for (i = 0; i < num_paths; i++)
1309                 free_combined_pair(q.queue[i]);
1310         free(q.queue);
1311 }
1312
1313 static const char *path_path(void *obj)
1314 {
1315         struct combine_diff_path *path = (struct combine_diff_path *)obj;
1316
1317         return path->path;
1318 }
1319
1320 void diff_tree_combined(const unsigned char *sha1,
1321                         const struct sha1_array *parents,
1322                         int dense,
1323                         struct rev_info *rev)
1324 {
1325         struct diff_options *opt = &rev->diffopt;
1326         struct diff_options diffopts;
1327         struct combine_diff_path *p, *paths = NULL;
1328         int i, num_paths, needsep, show_log_first, num_parent = parents->nr;
1329
1330         diffopts = *opt;
1331         copy_pathspec(&diffopts.pathspec, &opt->pathspec);
1332         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
1333         DIFF_OPT_SET(&diffopts, RECURSIVE);
1334         DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
1335         /* tell diff_tree to emit paths in sorted (=tree) order */
1336         diffopts.orderfile = NULL;
1337
1338         show_log_first = !!rev->loginfo && !rev->no_commit_id;
1339         needsep = 0;
1340         /* find set of paths that everybody touches */
1341         for (i = 0; i < num_parent; i++) {
1342                 /* show stat against the first parent even
1343                  * when doing combined diff.
1344                  */
1345                 int stat_opt = (opt->output_format &
1346                                 (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
1347                 if (i == 0 && stat_opt)
1348                         diffopts.output_format = stat_opt;
1349                 else
1350                         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
1351                 diff_tree_sha1(parents->sha1[i], sha1, "", &diffopts);
1352                 diffcore_std(&diffopts);
1353                 paths = intersect_paths(paths, i, num_parent);
1354
1355                 if (show_log_first && i == 0) {
1356                         show_log(rev);
1357
1358                         if (rev->verbose_header && opt->output_format)
1359                                 printf("%s%c", diff_line_prefix(opt),
1360                                        opt->line_termination);
1361                 }
1362
1363                 /* if showing diff, show it in requested order */
1364                 if (diffopts.output_format != DIFF_FORMAT_NO_OUTPUT &&
1365                     opt->orderfile) {
1366                         diffcore_order(opt->orderfile);
1367                 }
1368
1369                 diff_flush(&diffopts);
1370         }
1371
1372         /* find out surviving paths */
1373         for (num_paths = 0, p = paths; p; p = p->next) {
1374                 if (p->len)
1375                         num_paths++;
1376         }
1377
1378         /* order paths according to diffcore_order */
1379         if (opt->orderfile && num_paths) {
1380                 struct obj_order *o;
1381
1382                 o = xmalloc(sizeof(*o) * num_paths);
1383                 for (i = 0, p = paths; p; p = p->next, i++)
1384                         o[i].obj = p;
1385                 order_objects(opt->orderfile, path_path, o, num_paths);
1386                 for (i = 0; i < num_paths - 1; i++) {
1387                         p = o[i].obj;
1388                         p->next = o[i+1].obj;
1389                 }
1390
1391                 p = o[num_paths-1].obj;
1392                 p->next = NULL;
1393                 paths = o[0].obj;
1394                 free(o);
1395         }
1396
1397
1398         if (num_paths) {
1399                 if (opt->output_format & (DIFF_FORMAT_RAW |
1400                                           DIFF_FORMAT_NAME |
1401                                           DIFF_FORMAT_NAME_STATUS)) {
1402                         for (p = paths; p; p = p->next) {
1403                                 if (p->len)
1404                                         show_raw_diff(p, num_parent, rev);
1405                         }
1406                         needsep = 1;
1407                 }
1408                 else if (opt->output_format &
1409                          (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
1410                         needsep = 1;
1411                 else if (opt->output_format & DIFF_FORMAT_CALLBACK)
1412                         handle_combined_callback(opt, paths, num_parent, num_paths);
1413
1414                 if (opt->output_format & DIFF_FORMAT_PATCH) {
1415                         if (needsep)
1416                                 printf("%s%c", diff_line_prefix(opt),
1417                                        opt->line_termination);
1418                         for (p = paths; p; p = p->next) {
1419                                 if (p->len)
1420                                         show_patch_diff(p, num_parent, dense,
1421                                                         0, rev);
1422                         }
1423                 }
1424         }
1425
1426         /* Clean things up */
1427         while (paths) {
1428                 struct combine_diff_path *tmp = paths;
1429                 paths = paths->next;
1430                 free(tmp);
1431         }
1432
1433         free_pathspec(&diffopts.pathspec);
1434 }
1435
1436 void diff_tree_combined_merge(const struct commit *commit, int dense,
1437                               struct rev_info *rev)
1438 {
1439         struct commit_list *parent = get_saved_parents(rev, commit);
1440         struct sha1_array parents = SHA1_ARRAY_INIT;
1441
1442         while (parent) {
1443                 sha1_array_append(&parents, parent->item->object.sha1);
1444                 parent = parent->next;
1445         }
1446         diff_tree_combined(commit->object.sha1, &parents, dense, rev);
1447         sha1_array_clear(&parents);
1448 }