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                         sline[j++].flag |= mark | no_pre_delete;
 523
 524         again:
 525                 /* we know up to i is to be included.  where does the
 526                  * next uninteresting one start?
 527                  */
 528                 j = find_next(sline, mark, i, cnt, 1);
 529                 if (cnt < j)
 530                         break; /* the rest are all interesting */
 531
 532                 /* lookahead context lines */
 533                 k = find_next(sline, mark, j, cnt, 0);
 534                 j = adjust_hunk_tail(sline, all_mask, i, j);
 535
 536                 if (k < j + context) {
 537                         /* k is interesting and [j,k) are not, but
 538                          * paint them interesting because the gap is small.
 539                          */
 540                         while (j < k)
 541                                 sline[j++].flag |= mark;
 542                         i = k;
 543                         goto again;
 544                 }
 545
 546                 /* j is the first uninteresting line and there is
 547                  * no overlap beyond it within context lines.  Paint
 548                  * the trailing edge a bit.
 549                  */
 550                 i = k;
 551                 k = (j + context < cnt+1) ? j + context : cnt+1;
 552                 while (j < k)
 553                         sline[j++].flag |= mark;
 554         }
 555         return 1;
 556 }
 557
 558 static int make_hunks(struct sline *sline, unsigned long cnt,
 559                        int num_parent, int dense)
 560 {
 561         unsigned long all_mask = (1UL<<num_parent) - 1;
 562         unsigned long mark = (1UL<<num_parent);
 563         unsigned long i;
 564         int has_interesting = 0;
 565
 566         for (i = 0; i <= cnt; i++) {
 567                 if (interesting(&sline[i], all_mask))
 568                         sline[i].flag |= mark;
 569                 else
 570                         sline[i].flag &= ~mark;
 571         }
 572         if (!dense)
 573                 return give_context(sline, cnt, num_parent);
 574
 575         /* Look at each hunk, and if we have changes from only one
 576          * parent, or the changes are the same from all but one
 577          * parent, mark that uninteresting.
 578          */
 579         i = 0;
 580         while (i <= cnt) {
 581                 unsigned long j, hunk_begin, hunk_end;
 582                 unsigned long same_diff;
 583                 while (i <= cnt && !(sline[i].flag & mark))
 584                         i++;
 585                 if (cnt < i)
 586                         break; /* No more interesting hunks */
 587                 hunk_begin = i;
 588                 for (j = i + 1; j <= cnt; j++) {
 589                         if (!(sline[j].flag & mark)) {
 590                                 /* Look beyond the end to see if there
 591                                  * is an interesting line after this
 592                                  * hunk within context span.
 593                                  */
 594                                 unsigned long la; /* lookahead */
 595                                 int contin = 0;
 596                                 la = adjust_hunk_tail(sline, all_mask,
 597                                                      hunk_begin, j);
 598                                 la = (la + context < cnt + 1) ?
 599                                         (la + context) : cnt + 1;
 600                                 while (la && j <= --la) {
 601                                         if (sline[la].flag & mark) {
 602                                                 contin = 1;
 603                                                 break;
 604                                         }
 605                                 }
 606                                 if (!contin)
 607                                         break;
 608                                 j = la;
 609                         }
 610                 }
 611                 hunk_end = j;
 612
 613                 /* [i..hunk_end) are interesting.  Now is it really
 614                  * interesting?  We check if there are only two versions
 615                  * and the result matches one of them.  That is, we look
 616                  * at:
 617                  *   (+) line, which records lines added to which parents;
 618                  *       this line appears in the result.
 619                  *   (-) line, which records from what parents the line
 620                  *       was removed; this line does not appear in the result.
 621                  * then check the set of parents the result has difference
 622                  * from, from all lines.  If there are lines that has
 623                  * different set of parents that the result has differences
 624                  * from, that means we have more than two versions.
 625                  *
 626                  * Even when we have only two versions, if the result does
 627                  * not match any of the parents, the it should be considered
 628                  * interesting.  In such a case, we would have all '+' line.
 629                  * After passing the above "two versions" test, that would
 630                  * appear as "the same set of parents" to be "all parents".
 631                  */
 632                 same_diff = 0;
 633                 has_interesting = 0;
 634                 for (j = i; j < hunk_end && !has_interesting; j++) {
 635                         unsigned long this_diff = sline[j].flag & all_mask;
 636                         struct lline *ll = sline[j].lost;
 637                         if (this_diff) {
 638                                 /* This has some changes.  Is it the
 639                                  * same as others?
 640                                  */
 641                                 if (!same_diff)
 642                                         same_diff = this_diff;
 643                                 else if (same_diff != this_diff) {
 644                                         has_interesting = 1;
 645                                         break;
 646                                 }
 647                         }
 648                         while (ll && !has_interesting) {
 649                                 /* Lost this line from these parents;
 650                                  * who are they?  Are they the same?
 651                                  */
 652                                 this_diff = ll->parent_map;
 653                                 if (!same_diff)
 654                                         same_diff = this_diff;
 655                                 else if (same_diff != this_diff) {
 656                                         has_interesting = 1;
 657                                 }
 658                                 ll = ll->next;
 659                         }
 660                 }
 661
 662                 if (!has_interesting && same_diff != all_mask) {
 663                         /* This hunk is not that interesting after all */
 664                         for (j = hunk_begin; j < hunk_end; j++)
 665                                 sline[j].flag &= ~mark;
 666                 }
 667                 i = hunk_end;
 668         }
 669
 670         has_interesting = give_context(sline, cnt, num_parent);
 671         return has_interesting;
 672 }
 673
 674 static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
 675 {
 676         l0 = sline[l0].p_lno[n];
 677         l1 = sline[l1].p_lno[n];
 678         printf(" -%lu,%lu", l0, l1-l0-null_context);
 679 }
 680
 681 static int hunk_comment_line(const char *bol)
 682 {
 683         int ch;
 684
 685         if (!bol)
 686                 return 0;
 687         ch = *bol & 0xff;
 688         return (isalpha(ch) || ch == '_' || ch == '$');
 689 }
 690
 691 static void show_line_to_eol(const char *line, int len, const char *reset)
 692 {
 693         int saw_cr_at_eol = 0;
 694         if (len < 0)
 695                 len = strlen(line);
 696         saw_cr_at_eol = (len && line[len-1] == '\r');
 697
 698         printf("%.*s%s%s\n", len - saw_cr_at_eol, line,
 699                reset,
 700                saw_cr_at_eol ? "\r" : "");
 701 }
 702
 703 static void dump_sline(struct sline *sline, const char *line_prefix,
 704                        unsigned long cnt, int num_parent,
 705                        int use_color, int result_deleted)
 706 {
 707         unsigned long mark = (1UL<<num_parent);
 708         unsigned long no_pre_delete = (2UL<<num_parent);
 709         int i;
 710         unsigned long lno = 0;
 711         const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
 712         const char *c_func = diff_get_color(use_color, DIFF_FUNCINFO);
 713         const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
 714         const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
 715         const char *c_plain = diff_get_color(use_color, DIFF_PLAIN);
 716         const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 717
 718         if (result_deleted)
 719                 return; /* result deleted */
 720
 721         while (1) {
 722                 unsigned long hunk_end;
 723                 unsigned long rlines;
 724                 const char *hunk_comment = NULL;
 725                 unsigned long null_context = 0;
 726
 727                 while (lno <= cnt && !(sline[lno].flag & mark)) {
 728                         if (hunk_comment_line(sline[lno].bol))
 729                                 hunk_comment = sline[lno].bol;
 730                         lno++;
 731                 }
 732                 if (cnt < lno)
 733                         break;
 734                 else {
 735                         for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
 736                                 if (!(sline[hunk_end].flag & mark))
 737                                         break;
 738                 }
 739                 rlines = hunk_end - lno;
 740                 if (cnt < hunk_end)
 741                         rlines--; /* pointing at the last delete hunk */
 742
 743                 if (!context) {
 744                         /*
 745                          * Even when running with --unified=0, all
 746                          * lines in the hunk needs to be processed in
 747                          * the loop below in order to show the
 748                          * deletion recorded in lost_head.  However,
 749                          * we do not want to show the resulting line
 750                          * with all blank context markers in such a
 751                          * case.  Compensate.
 752                          */
 753                         unsigned long j;
 754                         for (j = lno; j < hunk_end; j++)
 755                                 if (!(sline[j].flag & (mark-1)))
 756                                         null_context++;
 757                         rlines -= null_context;
 758                 }
 759
 760                 printf("%s%s", line_prefix, c_frag);
 761                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 762                 for (i = 0; i < num_parent; i++)
 763                         show_parent_lno(sline, lno, hunk_end, i, null_context);
 764                 printf(" +%lu,%lu ", lno+1, rlines);
 765                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 766
 767                 if (hunk_comment) {
 768                         int comment_end = 0;
 769                         for (i = 0; i < 40; i++) {
 770                                 int ch = hunk_comment[i] & 0xff;
 771                                 if (!ch || ch == '\n')
 772                                         break;
 773                                 if (!isspace(ch))
 774                                     comment_end = i;
 775                         }
 776                         if (comment_end)
 777                                 printf("%s%s %s%s", c_reset,
 778                                                     c_plain, c_reset,
 779                                                     c_func);
 780                         for (i = 0; i < comment_end; i++)
 781                                 putchar(hunk_comment[i]);
 782                 }
 783
 784                 printf("%s\n", c_reset);
 785                 while (lno < hunk_end) {
 786                         struct lline *ll;
 787                         int j;
 788                         unsigned long p_mask;
 789                         struct sline *sl = &sline[lno++];
 790                         ll = (sl->flag & no_pre_delete) ? NULL : sl->lost;
 791                         while (ll) {
 792                                 printf("%s%s", line_prefix, c_old);
 793                                 for (j = 0; j < num_parent; j++) {
 794                                         if (ll->parent_map & (1UL<<j))
 795                                                 putchar('-');
 796                                         else
 797                                                 putchar(' ');
 798                                 }
 799                                 show_line_to_eol(ll->line, -1, c_reset);
 800                                 ll = ll->next;
 801                         }
 802                         if (cnt < lno)
 803                                 break;
 804                         p_mask = 1;
 805                         fputs(line_prefix, stdout);
 806                         if (!(sl->flag & (mark-1))) {
 807                                 /*
 808                                  * This sline was here to hang the
 809                                  * lost lines in front of it.
 810                                  */
 811                                 if (!context)
 812                                         continue;
 813                                 fputs(c_plain, stdout);
 814                         }
 815                         else
 816                                 fputs(c_new, stdout);
 817                         for (j = 0; j < num_parent; j++) {
 818                                 if (p_mask & sl->flag)
 819                                         putchar('+');
 820                                 else
 821                                         putchar(' ');
 822                                 p_mask <<= 1;
 823                         }
 824                         show_line_to_eol(sl->bol, sl->len, c_reset);
 825                 }
 826         }
 827 }
 828
 829 static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 830                                int i, int j)
 831 {
 832         /* We have already examined parent j and we know parent i
 833          * and parent j are the same, so reuse the combined result
 834          * of parent j for parent i.
 835          */
 836         unsigned long lno, imask, jmask;
 837         imask = (1UL<<i);
 838         jmask = (1UL<<j);
 839
 840         for (lno = 0; lno <= cnt; lno++) {
 841                 struct lline *ll = sline->lost;
 842                 sline->p_lno[i] = sline->p_lno[j];
 843                 while (ll) {
 844                         if (ll->parent_map & jmask)
 845                                 ll->parent_map |= imask;
 846                         ll = ll->next;
 847                 }
 848                 if (sline->flag & jmask)
 849                         sline->flag |= imask;
 850                 sline++;
 851         }
 852         /* the overall size of the file (sline[cnt]) */
 853         sline->p_lno[i] = sline->p_lno[j];
 854 }
 855
 856 static void dump_quoted_path(const char *head,
 857                              const char *prefix,
 858                              const char *path,
 859                              const char *line_prefix,
 860                              const char *c_meta, const char *c_reset)
 861 {
 862         static struct strbuf buf = STRBUF_INIT;
 863
 864         strbuf_reset(&buf);
 865         strbuf_addstr(&buf, line_prefix);
 866         strbuf_addstr(&buf, c_meta);
 867         strbuf_addstr(&buf, head);
 868         quote_two_c_style(&buf, prefix, path, 0);
 869         strbuf_addstr(&buf, c_reset);
 870         puts(buf.buf);
 871 }
 872
 873 static void show_combined_header(struct combine_diff_path *elem,
 874                                  int num_parent,
 875                                  int dense,
 876                                  struct rev_info *rev,
 877                                  const char *line_prefix,
 878                                  int mode_differs,
 879                                  int show_file_header)
 880 {
 881         struct diff_options *opt = &rev->diffopt;
 882         int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
 883         const char *a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
 884         const char *b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
 885         const char *c_meta = diff_get_color_opt(opt, DIFF_METAINFO);
 886         const char *c_reset = diff_get_color_opt(opt, DIFF_RESET);
 887         const char *abb;
 888         int added = 0;
 889         int deleted = 0;
 890         int i;
 891
 892         if (rev->loginfo && !rev->no_commit_id)
 893                 show_log(rev);
 894
 895         dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
 896                          "", elem->path, line_prefix, c_meta, c_reset);
 897         printf("%s%sindex ", line_prefix, c_meta);
 898         for (i = 0; i < num_parent; i++) {
 899                 abb = find_unique_abbrev(elem->parent[i].sha1,
 900                                          abbrev);
 901                 printf("%s%s", i ? "," : "", abb);
 902         }
 903         abb = find_unique_abbrev(elem->sha1, abbrev);
 904         printf("..%s%s\n", abb, c_reset);
 905
 906         if (mode_differs) {
 907                 deleted = !elem->mode;
 908
 909                 /* We say it was added if nobody had it */
 910                 added = !deleted;
 911                 for (i = 0; added && i < num_parent; i++)
 912                         if (elem->parent[i].status !=
 913                             DIFF_STATUS_ADDED)
 914                                 added = 0;
 915                 if (added)
 916                         printf("%s%snew file mode %06o",
 917                                line_prefix, c_meta, elem->mode);
 918                 else {
 919                         if (deleted)
 920                                 printf("%s%sdeleted file ",
 921                                        line_prefix, c_meta);
 922                         printf("mode ");
 923                         for (i = 0; i < num_parent; i++) {
 924                                 printf("%s%06o", i ? "," : "",
 925                                        elem->parent[i].mode);
 926                         }
 927                         if (elem->mode)
 928                                 printf("..%06o", elem->mode);
 929                 }
 930                 printf("%s\n", c_reset);
 931         }
 932
 933         if (!show_file_header)
 934                 return;
 935
 936         if (added)
 937                 dump_quoted_path("--- ", "", "/dev/null",
 938                                  line_prefix, c_meta, c_reset);
 939         else
 940                 dump_quoted_path("--- ", a_prefix, elem->path,
 941                                  line_prefix, c_meta, c_reset);
 942         if (deleted)
 943                 dump_quoted_path("+++ ", "", "/dev/null",
 944                                  line_prefix, c_meta, c_reset);
 945         else
 946                 dump_quoted_path("+++ ", b_prefix, elem->path,
 947                                  line_prefix, c_meta, c_reset);
 948 }
 949
 950 static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 951                             int dense, int working_tree_file,
 952                             struct rev_info *rev)
 953 {
 954         struct diff_options *opt = &rev->diffopt;
 955         unsigned long result_size, cnt, lno;
 956         int result_deleted = 0;
 957         char *result, *cp;
 958         struct sline *sline; /* survived lines */
 959         int mode_differs = 0;
 960         int i, show_hunks;
 961         mmfile_t result_file;
 962         struct userdiff_driver *userdiff;
 963         struct userdiff_driver *textconv = NULL;
 964         int is_binary;
 965         const char *line_prefix = diff_line_prefix(opt);
 966
 967         context = opt->context;
 968         userdiff = userdiff_find_by_path(elem->path);
 969         if (!userdiff)
 970                 userdiff = userdiff_find_by_name("default");
 971         if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV))
 972                 textconv = userdiff_get_textconv(userdiff);
 973
 974         /* Read the result of merge first */
 975         if (!working_tree_file)
 976                 result = grab_blob(elem->sha1, elem->mode, &result_size,
 977                                    textconv, elem->path);
 978         else {
 979                 /* Used by diff-tree to read from the working tree */
 980                 struct stat st;
 981                 int fd = -1;
 982
 983                 if (lstat(elem->path, &st) < 0)
 984                         goto deleted_file;
 985
 986                 if (S_ISLNK(st.st_mode)) {
 987                         struct strbuf buf = STRBUF_INIT;
 988
 989                         if (strbuf_readlink(&buf, elem->path, st.st_size) < 0) {
 990                                 error("readlink(%s): %s", elem->path,
 991                                       strerror(errno));
 992                                 return;
 993                         }
 994                         result_size = buf.len;
 995                         result = strbuf_detach(&buf, NULL);
 996                         elem->mode = canon_mode(st.st_mode);
 997                 } else if (S_ISDIR(st.st_mode)) {
 998                         unsigned char sha1[20];
 999                         if (resolve_gitlink_ref(elem->path, "HEAD", sha1) < 0)
1000                                 result = grab_blob(elem->sha1, elem->mode,
1001                                                    &result_size, NULL, NULL);
1002                         else
1003                                 result = grab_blob(sha1, elem->mode,
1004                                                    &result_size, NULL, NULL);
1005                 } else if (textconv) {
1006                         struct diff_filespec *df = alloc_filespec(elem->path);
1007                         fill_filespec(df, null_sha1, 0, st.st_mode);
1008                         result_size = fill_textconv(textconv, df, &result);
1009                         free_filespec(df);
1010                 } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
1011                         size_t len = xsize_t(st.st_size);
1012                         ssize_t done;
1013                         int is_file, i;
1014
1015                         elem->mode = canon_mode(st.st_mode);
1016                         /* if symlinks don't work, assume symlink if all parents
1017                          * are symlinks
1018                          */
1019                         is_file = has_symlinks;
1020                         for (i = 0; !is_file && i < num_parent; i++)
1021                                 is_file = !S_ISLNK(elem->parent[i].mode);
1022                         if (!is_file)
1023                                 elem->mode = canon_mode(S_IFLNK);
1024
1025                         result_size = len;
1026                         result = xmalloc(len + 1);
1027
1028                         done = read_in_full(fd, result, len);
1029                         if (done < 0)
1030                                 die_errno("read error '%s'", elem->path);
1031                         else if (done < len)
1032                                 die("early EOF '%s'", elem->path);
1033
1034                         result[len] = 0;
1035
1036                         /* If not a fake symlink, apply filters, e.g. autocrlf */
1037                         if (is_file) {
1038                                 struct strbuf buf = STRBUF_INIT;
1039
1040                                 if (convert_to_git(elem->path, result, len, &buf, safe_crlf)) {
1041                                         free(result);
1042                                         result = strbuf_detach(&buf, &len);
1043                                         result_size = len;
1044                                 }
1045                         }
1046                 }
1047                 else {
1048                 deleted_file:
1049                         result_deleted = 1;
1050                         result_size = 0;
1051                         elem->mode = 0;
1052                         result = xcalloc(1, 1);
1053                 }
1054
1055                 if (0 <= fd)
1056                         close(fd);
1057         }
1058
1059         for (i = 0; i < num_parent; i++) {
1060                 if (elem->parent[i].mode != elem->mode) {
1061                         mode_differs = 1;
1062                         break;
1063                 }
1064         }
1065
1066         if (textconv)
1067                 is_binary = 0;
1068         else if (userdiff->binary != -1)
1069                 is_binary = userdiff->binary;
1070         else {
1071                 is_binary = buffer_is_binary(result, result_size);
1072                 for (i = 0; !is_binary && i < num_parent; i++) {
1073                         char *buf;
1074                         unsigned long size;
1075                         buf = grab_blob(elem->parent[i].sha1,
1076                                         elem->parent[i].mode,
1077                                         &size, NULL, NULL);
1078                         if (buffer_is_binary(buf, size))
1079                                 is_binary = 1;
1080                         free(buf);
1081                 }
1082         }
1083         if (is_binary) {
1084                 show_combined_header(elem, num_parent, dense, rev,
1085                                      line_prefix, mode_differs, 0);
1086                 printf("Binary files differ\n");
1087                 free(result);
1088                 return;
1089         }
1090
1091         for (cnt = 0, cp = result; cp < result + result_size; cp++) {
1092                 if (*cp == '\n')
1093                         cnt++;
1094         }
1095         if (result_size && result[result_size-1] != '\n')
1096                 cnt++; /* incomplete line */
1097
1098         sline = xcalloc(cnt+2, sizeof(*sline));
1099         sline[0].bol = result;
1100         for (lno = 0, cp = result; cp < result + result_size; cp++) {
1101                 if (*cp == '\n') {
1102                         sline[lno].len = cp - sline[lno].bol;
1103                         lno++;
1104                         if (lno < cnt)
1105                                 sline[lno].bol = cp + 1;
1106                 }
1107         }
1108         if (result_size && result[result_size-1] != '\n')
1109                 sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
1110
1111         result_file.ptr = result;
1112         result_file.size = result_size;
1113
1114         /* Even p_lno[cnt+1] is valid -- that is for the end line number
1115          * for deletion hunk at the end.
1116          */
1117         sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
1118         for (lno = 0; lno <= cnt; lno++)
1119                 sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
1120
1121         for (i = 0; i < num_parent; i++) {
1122                 int j;
1123                 for (j = 0; j < i; j++) {
1124                         if (!hashcmp(elem->parent[i].sha1,
1125                                      elem->parent[j].sha1)) {
1126                                 reuse_combine_diff(sline, cnt, i, j);
1127                                 break;
1128                         }
1129                 }
1130                 if (i <= j)
1131                         combine_diff(elem->parent[i].sha1,
1132                                      elem->parent[i].mode,
1133                                      &result_file, sline,
1134                                      cnt, i, num_parent, result_deleted,
1135                                      textconv, elem->path, opt->xdl_opts);
1136         }
1137
1138         show_hunks = make_hunks(sline, cnt, num_parent, dense);
1139
1140         if (show_hunks || mode_differs || working_tree_file) {
1141                 show_combined_header(elem, num_parent, dense, rev,
1142                                      line_prefix, mode_differs, 1);
1143                 dump_sline(sline, line_prefix, cnt, num_parent,
1144                            opt->use_color, result_deleted);
1145         }
1146         free(result);
1147
1148         for (lno = 0; lno < cnt; lno++) {
1149                 if (sline[lno].lost) {
1150                         struct lline *ll = sline[lno].lost;
1151                         while (ll) {
1152                                 struct lline *tmp = ll;
1153                                 ll = ll->next;
1154                                 free(tmp);
1155                         }
1156                 }
1157         }
1158         free(sline[0].p_lno);
1159         free(sline);
1160 }
1161
1162 static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
1163 {
1164         struct diff_options *opt = &rev->diffopt;
1165         int line_termination, inter_name_termination, i;
1166         const char *line_prefix = diff_line_prefix(opt);
1167
1168         line_termination = opt->line_termination;
1169         inter_name_termination = '\t';
1170         if (!line_termination)
1171                 inter_name_termination = 0;
1172
1173         if (rev->loginfo && !rev->no_commit_id)
1174                 show_log(rev);
1175
1176
1177         if (opt->output_format & DIFF_FORMAT_RAW) {
1178                 printf("%s", line_prefix);
1179
1180                 /* As many colons as there are parents */
1181                 for (i = 0; i < num_parent; i++)
1182                         putchar(':');
1183
1184                 /* Show the modes */
1185                 for (i = 0; i < num_parent; i++)
1186                         printf("%06o ", p->parent[i].mode);
1187                 printf("%06o", p->mode);
1188
1189                 /* Show sha1's */
1190                 for (i = 0; i < num_parent; i++)
1191                         printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
1192                                                          opt->abbrev));
1193                 printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
1194         }
1195
1196         if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
1197                 for (i = 0; i < num_parent; i++)
1198                         putchar(p->parent[i].status);
1199                 putchar(inter_name_termination);
1200         }
1201
1202         write_name_quoted(p->path, stdout, line_termination);
1203 }
1204
1205 /*
1206  * The result (p->elem) is from the working tree and their
1207  * parents are typically from multiple stages during a merge
1208  * (i.e. diff-files) or the state in HEAD and in the index
1209  * (i.e. diff-index).
1210  */
1211 void show_combined_diff(struct combine_diff_path *p,
1212                        int num_parent,
1213                        int dense,
1214                        struct rev_info *rev)
1215 {
1216         struct diff_options *opt = &rev->diffopt;
1217
1218         if (!p->len)
1219                 return;
1220         if (opt->output_format & (DIFF_FORMAT_RAW |
1221                                   DIFF_FORMAT_NAME |
1222                                   DIFF_FORMAT_NAME_STATUS))
1223                 show_raw_diff(p, num_parent, rev);
1224         else if (opt->output_format & DIFF_FORMAT_PATCH)
1225                 show_patch_diff(p, num_parent, dense, 1, rev);
1226 }
1227
1228 static void free_combined_pair(struct diff_filepair *pair)
1229 {
1230         free(pair->two);
1231         free(pair);
1232 }
1233
1234 /*
1235  * A combine_diff_path expresses N parents on the LHS against 1 merge
1236  * result. Synthesize a diff_filepair that has N entries on the "one"
1237  * side and 1 entry on the "two" side.
1238  *
1239  * In the future, we might want to add more data to combine_diff_path
1240  * so that we can fill fields we are ignoring (most notably, size) here,
1241  * but currently nobody uses it, so this should suffice for now.
1242  */
1243 static struct diff_filepair *combined_pair(struct combine_diff_path *p,
1244                                            int num_parent)
1245 {
1246         int i;
1247         struct diff_filepair *pair;
1248         struct diff_filespec *pool;
1249
1250         pair = xmalloc(sizeof(*pair));
1251         pool = xcalloc(num_parent + 1, sizeof(struct diff_filespec));
1252         pair->one = pool + 1;
1253         pair->two = pool;
1254
1255         for (i = 0; i < num_parent; i++) {
1256                 pair->one[i].path = p->path;
1257                 pair->one[i].mode = p->parent[i].mode;
1258                 hashcpy(pair->one[i].sha1, p->parent[i].sha1);
1259                 pair->one[i].sha1_valid = !is_null_sha1(p->parent[i].sha1);
1260                 pair->one[i].has_more_entries = 1;
1261         }
1262         pair->one[num_parent - 1].has_more_entries = 0;
1263
1264         pair->two->path = p->path;
1265         pair->two->mode = p->mode;
1266         hashcpy(pair->two->sha1, p->sha1);
1267         pair->two->sha1_valid = !is_null_sha1(p->sha1);
1268         return pair;
1269 }
1270
1271 static void handle_combined_callback(struct diff_options *opt,
1272                                      struct combine_diff_path *paths,
1273                                      int num_parent,
1274                                      int num_paths)
1275 {
1276         struct combine_diff_path *p;
1277         struct diff_queue_struct q;
1278         int i;
1279
1280         q.queue = xcalloc(num_paths, sizeof(struct diff_filepair *));
1281         q.alloc = num_paths;
1282         q.nr = num_paths;
1283         for (i = 0, p = paths; p; p = p->next) {
1284                 if (!p->len)
1285                         continue;
1286                 q.queue[i++] = combined_pair(p, num_parent);
1287         }
1288         opt->format_callback(&q, opt, opt->format_callback_data);
1289         for (i = 0; i < num_paths; i++)
1290                 free_combined_pair(q.queue[i]);
1291         free(q.queue);
1292 }
1293
1294 void diff_tree_combined(const unsigned char *sha1,
1295                         const struct sha1_array *parents,
1296                         int dense,
1297                         struct rev_info *rev)
1298 {
1299         struct diff_options *opt = &rev->diffopt;
1300         struct diff_options diffopts;
1301         struct combine_diff_path *p, *paths = NULL;
1302         int i, num_paths, needsep, show_log_first, num_parent = parents->nr;
1303
1304         diffopts = *opt;
1305         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
1306         DIFF_OPT_SET(&diffopts, RECURSIVE);
1307         DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
1308
1309         show_log_first = !!rev->loginfo && !rev->no_commit_id;
1310         needsep = 0;
1311         /* find set of paths that everybody touches */
1312         for (i = 0; i < num_parent; i++) {
1313                 /* show stat against the first parent even
1314                  * when doing combined diff.
1315                  */
1316                 int stat_opt = (opt->output_format &
1317                                 (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
1318                 if (i == 0 && stat_opt)
1319                         diffopts.output_format = stat_opt;
1320                 else
1321                         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
1322                 diff_tree_sha1(parents->sha1[i], sha1, "", &diffopts);
1323                 diffcore_std(&diffopts);
1324                 paths = intersect_paths(paths, i, num_parent);
1325
1326                 if (show_log_first && i == 0) {
1327                         show_log(rev);
1328
1329                         if (rev->verbose_header && opt->output_format)
1330                                 printf("%s%c", diff_line_prefix(opt),
1331                                        opt->line_termination);
1332                 }
1333                 diff_flush(&diffopts);
1334         }
1335
1336         /* find out surviving paths */
1337         for (num_paths = 0, p = paths; p; p = p->next) {
1338                 if (p->len)
1339                         num_paths++;
1340         }
1341         if (num_paths) {
1342                 if (opt->output_format & (DIFF_FORMAT_RAW |
1343                                           DIFF_FORMAT_NAME |
1344                                           DIFF_FORMAT_NAME_STATUS)) {
1345                         for (p = paths; p; p = p->next) {
1346                                 if (p->len)
1347                                         show_raw_diff(p, num_parent, rev);
1348                         }
1349                         needsep = 1;
1350                 }
1351                 else if (opt->output_format &
1352                          (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
1353                         needsep = 1;
1354                 else if (opt->output_format & DIFF_FORMAT_CALLBACK)
1355                         handle_combined_callback(opt, paths, num_parent, num_paths);
1356
1357                 if (opt->output_format & DIFF_FORMAT_PATCH) {
1358                         if (needsep)
1359                                 printf("%s%c", diff_line_prefix(opt),
1360                                        opt->line_termination);
1361                         for (p = paths; p; p = p->next) {
1362                                 if (p->len)
1363                                         show_patch_diff(p, num_parent, dense,
1364                                                         0, rev);
1365                         }
1366                 }
1367         }
1368
1369         /* Clean things up */
1370         while (paths) {
1371                 struct combine_diff_path *tmp = paths;
1372                 paths = paths->next;
1373                 free(tmp);
1374         }
1375 }
1376
1377 void diff_tree_combined_merge(const struct commit *commit, int dense,
1378                               struct rev_info *rev)
1379 {
1380         struct commit_list *parent = commit->parents;
1381         struct sha1_array parents = SHA1_ARRAY_INIT;
1382
1383         while (parent) {
1384                 sha1_array_append(&parents, parent->item->object.sha1);
1385                 parent = parent->next;
1386         }
1387         diff_tree_combined(commit->object.sha1, &parents, dense, rev);
1388         sha1_array_clear(&parents);
1389 }