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