combine-diff.c

   1 #include "cache.h"
   2 #include "commit.h"
   3 #include "blob.h"
   4 #include "diff.h"
   5 #include "diffcore.h"
   6 #include "quote.h"
   7 #include "xdiff-interface.h"
   8 #include "log-tree.h"
   9 #include "refs.h"
  10
  11 static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
  12 {
  13         struct diff_queue_struct *q = &diff_queued_diff;
  14         struct combine_diff_path *p;
  15         int i;
  16
  17         if (!n) {
  18                 struct combine_diff_path *list = NULL, **tail = &list;
  19                 for (i = 0; i < q->nr; i++) {
  20                         int len;
  21                         const char *path;
  22                         if (diff_unmodified_pair(q->queue[i]))
  23                                 continue;
  24                         path = q->queue[i]->two->path;
  25                         len = strlen(path);
  26                         p = xmalloc(combine_diff_path_size(num_parent, len));
  27                         p->path = (char*) &(p->parent[num_parent]);
  28                         memcpy(p->path, path, len);
  29                         p->path[len] = 0;
  30                         p->len = len;
  31                         p->next = NULL;
  32                         memset(p->parent, 0,
  33                                sizeof(p->parent[0]) * num_parent);
  34
  35                         hashcpy(p->sha1, q->queue[i]->two->sha1);
  36                         p->mode = q->queue[i]->two->mode;
  37                         hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
  38                         p->parent[n].mode = q->queue[i]->one->mode;
  39                         p->parent[n].status = q->queue[i]->status;
  40                         *tail = p;
  41                         tail = &p->next;
  42                 }
  43                 return list;
  44         }
  45
  46         for (p = curr; p; p = p->next) {
  47                 int found = 0;
  48                 if (!p->len)
  49                         continue;
  50                 for (i = 0; i < q->nr; i++) {
  51                         const char *path;
  52                         int len;
  53
  54                         if (diff_unmodified_pair(q->queue[i]))
  55                                 continue;
  56                         path = q->queue[i]->two->path;
  57                         len = strlen(path);
  58                         if (len == p->len && !memcmp(path, p->path, len)) {
  59                                 found = 1;
  60                                 hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
  61                                 p->parent[n].mode = q->queue[i]->one->mode;
  62                                 p->parent[n].status = q->queue[i]->status;
  63                                 break;
  64                         }
  65                 }
  66                 if (!found)
  67                         p->len = 0;
  68         }
  69         return curr;
  70 }
  71
  72 /* Lines lost from parent */
  73 struct lline {
  74         struct lline *next;
  75         int len;
  76         unsigned long parent_map;
  77         char line[FLEX_ARRAY];
  78 };
  79
  80 /* Lines surviving in the merge result */
  81 struct sline {
  82         struct lline *lost_head, **lost_tail;
  83         char *bol;
  84         int len;
  85         /* bit 0 up to (N-1) are on if the parent has this line (i.e.
  86          * we did not change it).
  87          * bit N is used for "interesting" lines, including context.
  88          * bit (N+1) is used for "do not show deletion before this".
  89          */
  90         unsigned long flag;
  91         unsigned long *p_lno;
  92 };
  93
  94 static char *grab_blob(const unsigned char *sha1, unsigned int mode, unsigned long *size)
  95 {
  96         char *blob;
  97         enum object_type type;
  98
  99         if (S_ISGITLINK(mode)) {
 100                 blob = xmalloc(100);
 101                 *size = snprintf(blob, 100,
 102                                  "Subproject commit %s\n", sha1_to_hex(sha1));
 103         } else if (is_null_sha1(sha1)) {
 104                 /* deleted blob */
 105                 *size = 0;
 106                 return xcalloc(1, 1);
 107         } else {
 108                 blob = read_sha1_file(sha1, &type, size);
 109                 if (type != OBJ_BLOB)
 110                         die("object '%s' is not a blob!", sha1_to_hex(sha1));
 111         }
 112         return blob;
 113 }
 114
 115 static void append_lost(struct sline *sline, int n, const char *line, int len)
 116 {
 117         struct lline *lline;
 118         unsigned long this_mask = (1UL<<n);
 119         if (line[len-1] == '\n')
 120                 len--;
 121
 122         /* Check to see if we can squash things */
 123         if (sline->lost_head) {
 124                 struct lline *last_one = NULL;
 125                 /* We cannot squash it with earlier one */
 126                 for (lline = sline->lost_head;
 127                      lline;
 128                      lline = lline->next)
 129                         if (lline->parent_map & this_mask)
 130                                 last_one = lline;
 131                 lline = last_one ? last_one->next : sline->lost_head;
 132                 while (lline) {
 133                         if (lline->len == len &&
 134                             !memcmp(lline->line, line, len)) {
 135                                 lline->parent_map |= this_mask;
 136                                 return;
 137                         }
 138                         lline = lline->next;
 139                 }
 140         }
 141
 142         lline = xmalloc(sizeof(*lline) + len + 1);
 143         lline->len = len;
 144         lline->next = NULL;
 145         lline->parent_map = this_mask;
 146         memcpy(lline->line, line, len);
 147         lline->line[len] = 0;
 148         *sline->lost_tail = lline;
 149         sline->lost_tail = &lline->next;
 150 }
 151
 152 struct combine_diff_state {
 153         struct xdiff_emit_state xm;
 154
 155         unsigned int lno;
 156         int ob, on, nb, nn;
 157         unsigned long nmask;
 158         int num_parent;
 159         int n;
 160         struct sline *sline;
 161         struct sline *lost_bucket;
 162 };
 163
 164 static void consume_line(void *state_, char *line, unsigned long len)
 165 {
 166         struct combine_diff_state *state = state_;
 167         if (5 < len && !memcmp("@@ -", line, 4)) {
 168                 if (parse_hunk_header(line, len,
 169                                       &state->ob, &state->on,
 170                                       &state->nb, &state->nn))
 171                         return;
 172                 state->lno = state->nb;
 173                 if (!state->nb)
 174                         /* @@ -1,2 +0,0 @@ to remove the
 175                          * first two lines...
 176                          */
 177                         state->nb = 1;
 178                 if (state->nn == 0)
 179                         /* @@ -X,Y +N,0 @@ removed Y lines
 180                          * that would have come *after* line N
 181                          * in the result.  Our lost buckets hang
 182                          * to the line after the removed lines,
 183                          */
 184                         state->lost_bucket = &state->sline[state->nb];
 185                 else
 186                         state->lost_bucket = &state->sline[state->nb-1];
 187                 if (!state->sline[state->nb-1].p_lno)
 188                         state->sline[state->nb-1].p_lno =
 189                                 xcalloc(state->num_parent,
 190                                         sizeof(unsigned long));
 191                 state->sline[state->nb-1].p_lno[state->n] = state->ob;
 192                 return;
 193         }
 194         if (!state->lost_bucket)
 195                 return; /* not in any hunk yet */
 196         switch (line[0]) {
 197         case '-':
 198                 append_lost(state->lost_bucket, state->n, line+1, len-1);
 199                 break;
 200         case '+':
 201                 state->sline[state->lno-1].flag |= state->nmask;
 202                 state->lno++;
 203                 break;
 204         }
 205 }
 206
 207 static void combine_diff(const unsigned char *parent, unsigned int mode,
 208                          mmfile_t *result_file,
 209                          struct sline *sline, unsigned int cnt, int n,
 210                          int num_parent)
 211 {
 212         unsigned int p_lno, lno;
 213         unsigned long nmask = (1UL << n);
 214         xpparam_t xpp;
 215         xdemitconf_t xecfg;
 216         mmfile_t parent_file;
 217         xdemitcb_t ecb;
 218         struct combine_diff_state state;
 219         unsigned long sz;
 220
 221         if (!cnt)
 222                 return; /* result deleted */
 223
 224         parent_file.ptr = grab_blob(parent, mode, &sz);
 225         parent_file.size = sz;
 226         xpp.flags = XDF_NEED_MINIMAL;
 227         memset(&xecfg, 0, sizeof(xecfg));
 228         ecb.outf = xdiff_outf;
 229         ecb.priv = &state;
 230         memset(&state, 0, sizeof(state));
 231         state.xm.consume = consume_line;
 232         state.nmask = nmask;
 233         state.sline = sline;
 234         state.lno = 1;
 235         state.num_parent = num_parent;
 236         state.n = n;
 237
 238         xdi_diff(&parent_file, result_file, &xpp, &xecfg, &ecb);
 239         free(parent_file.ptr);
 240
 241         /* Assign line numbers for this parent.
 242          *
 243          * sline[lno].p_lno[n] records the first line number
 244          * (counting from 1) for parent N if the final hunk display
 245          * started by showing sline[lno] (possibly showing the lost
 246          * lines attached to it first).
 247          */
 248         for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
 249                 struct lline *ll;
 250                 sline[lno].p_lno[n] = p_lno;
 251
 252                 /* How many lines would this sline advance the p_lno? */
 253                 ll = sline[lno].lost_head;
 254                 while (ll) {
 255                         if (ll->parent_map & nmask)
 256                                 p_lno++; /* '-' means parent had it */
 257                         ll = ll->next;
 258                 }
 259                 if (lno < cnt && !(sline[lno].flag & nmask))
 260                         p_lno++; /* no '+' means parent had it */
 261         }
 262         sline[lno].p_lno[n] = p_lno; /* trailer */
 263 }
 264
 265 static unsigned long context = 3;
 266 static char combine_marker = '@';
 267
 268 static int interesting(struct sline *sline, unsigned long all_mask)
 269 {
 270         /* If some parents lost lines here, or if we have added to
 271          * some parent, it is interesting.
 272          */
 273         return ((sline->flag & all_mask) || sline->lost_head);
 274 }
 275
 276 static unsigned long adjust_hunk_tail(struct sline *sline,
 277                                       unsigned long all_mask,
 278                                       unsigned long hunk_begin,
 279                                       unsigned long i)
 280 {
 281         /* i points at the first uninteresting line.  If the last line
 282          * of the hunk was interesting only because it has some
 283          * deletion, then it is not all that interesting for the
 284          * purpose of giving trailing context lines.  This is because
 285          * we output '-' line and then unmodified sline[i-1] itself in
 286          * that case which gives us one extra context line.
 287          */
 288         if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
 289                 i--;
 290         return i;
 291 }
 292
 293 static unsigned long find_next(struct sline *sline,
 294                                unsigned long mark,
 295                                unsigned long i,
 296                                unsigned long cnt,
 297                                int look_for_uninteresting)
 298 {
 299         /* We have examined up to i-1 and are about to look at i.
 300          * Find next interesting or uninteresting line.  Here,
 301          * "interesting" does not mean interesting(), but marked by
 302          * the give_context() function below (i.e. it includes context
 303          * lines that are not interesting to interesting() function
 304          * that are surrounded by interesting() ones.
 305          */
 306         while (i <= cnt)
 307                 if (look_for_uninteresting
 308                     ? !(sline[i].flag & mark)
 309                     : (sline[i].flag & mark))
 310                         return i;
 311                 else
 312                         i++;
 313         return i;
 314 }
 315
 316 static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 317 {
 318         unsigned long all_mask = (1UL<<num_parent) - 1;
 319         unsigned long mark = (1UL<<num_parent);
 320         unsigned long no_pre_delete = (2UL<<num_parent);
 321         unsigned long i;
 322
 323         /* Two groups of interesting lines may have a short gap of
 324          * uninteresting lines.  Connect such groups to give them a
 325          * bit of context.
 326          *
 327          * We first start from what the interesting() function says,
 328          * and mark them with "mark", and paint context lines with the
 329          * mark.  So interesting() would still say false for such context
 330          * lines but they are treated as "interesting" in the end.
 331          */
 332         i = find_next(sline, mark, 0, cnt, 0);
 333         if (cnt < i)
 334                 return 0;
 335
 336         while (i <= cnt) {
 337                 unsigned long j = (context < i) ? (i - context) : 0;
 338                 unsigned long k;
 339
 340                 /* Paint a few lines before the first interesting line. */
 341                 while (j < i)
 342                         sline[j++].flag |= mark | no_pre_delete;
 343
 344         again:
 345                 /* we know up to i is to be included.  where does the
 346                  * next uninteresting one start?
 347                  */
 348                 j = find_next(sline, mark, i, cnt, 1);
 349                 if (cnt < j)
 350                         break; /* the rest are all interesting */
 351
 352                 /* lookahead context lines */
 353                 k = find_next(sline, mark, j, cnt, 0);
 354                 j = adjust_hunk_tail(sline, all_mask, i, j);
 355
 356                 if (k < j + context) {
 357                         /* k is interesting and [j,k) are not, but
 358                          * paint them interesting because the gap is small.
 359                          */
 360                         while (j < k)
 361                                 sline[j++].flag |= mark;
 362                         i = k;
 363                         goto again;
 364                 }
 365
 366                 /* j is the first uninteresting line and there is
 367                  * no overlap beyond it within context lines.  Paint
 368                  * the trailing edge a bit.
 369                  */
 370                 i = k;
 371                 k = (j + context < cnt+1) ? j + context : cnt+1;
 372                 while (j < k)
 373                         sline[j++].flag |= mark;
 374         }
 375         return 1;
 376 }
 377
 378 static int make_hunks(struct sline *sline, unsigned long cnt,
 379                        int num_parent, int dense)
 380 {
 381         unsigned long all_mask = (1UL<<num_parent) - 1;
 382         unsigned long mark = (1UL<<num_parent);
 383         unsigned long i;
 384         int has_interesting = 0;
 385
 386         for (i = 0; i <= cnt; i++) {
 387                 if (interesting(&sline[i], all_mask))
 388                         sline[i].flag |= mark;
 389                 else
 390                         sline[i].flag &= ~mark;
 391         }
 392         if (!dense)
 393                 return give_context(sline, cnt, num_parent);
 394
 395         /* Look at each hunk, and if we have changes from only one
 396          * parent, or the changes are the same from all but one
 397          * parent, mark that uninteresting.
 398          */
 399         i = 0;
 400         while (i <= cnt) {
 401                 unsigned long j, hunk_begin, hunk_end;
 402                 unsigned long same_diff;
 403                 while (i <= cnt && !(sline[i].flag & mark))
 404                         i++;
 405                 if (cnt < i)
 406                         break; /* No more interesting hunks */
 407                 hunk_begin = i;
 408                 for (j = i + 1; j <= cnt; j++) {
 409                         if (!(sline[j].flag & mark)) {
 410                                 /* Look beyond the end to see if there
 411                                  * is an interesting line after this
 412                                  * hunk within context span.
 413                                  */
 414                                 unsigned long la; /* lookahead */
 415                                 int contin = 0;
 416                                 la = adjust_hunk_tail(sline, all_mask,
 417                                                      hunk_begin, j);
 418                                 la = (la + context < cnt + 1) ?
 419                                         (la + context) : cnt + 1;
 420                                 while (j <= --la) {
 421                                         if (sline[la].flag & mark) {
 422                                                 contin = 1;
 423                                                 break;
 424                                         }
 425                                 }
 426                                 if (!contin)
 427                                         break;
 428                                 j = la;
 429                         }
 430                 }
 431                 hunk_end = j;
 432
 433                 /* [i..hunk_end) are interesting.  Now is it really
 434                  * interesting?  We check if there are only two versions
 435                  * and the result matches one of them.  That is, we look
 436                  * at:
 437                  *   (+) line, which records lines added to which parents;
 438                  *       this line appears in the result.
 439                  *   (-) line, which records from what parents the line
 440                  *       was removed; this line does not appear in the result.
 441                  * then check the set of parents the result has difference
 442                  * from, from all lines.  If there are lines that has
 443                  * different set of parents that the result has differences
 444                  * from, that means we have more than two versions.
 445                  *
 446                  * Even when we have only two versions, if the result does
 447                  * not match any of the parents, the it should be considered
 448                  * interesting.  In such a case, we would have all '+' line.
 449                  * After passing the above "two versions" test, that would
 450                  * appear as "the same set of parents" to be "all parents".
 451                  */
 452                 same_diff = 0;
 453                 has_interesting = 0;
 454                 for (j = i; j < hunk_end && !has_interesting; j++) {
 455                         unsigned long this_diff = sline[j].flag & all_mask;
 456                         struct lline *ll = sline[j].lost_head;
 457                         if (this_diff) {
 458                                 /* This has some changes.  Is it the
 459                                  * same as others?
 460                                  */
 461                                 if (!same_diff)
 462                                         same_diff = this_diff;
 463                                 else if (same_diff != this_diff) {
 464                                         has_interesting = 1;
 465                                         break;
 466                                 }
 467                         }
 468                         while (ll && !has_interesting) {
 469                                 /* Lost this line from these parents;
 470                                  * who are they?  Are they the same?
 471                                  */
 472                                 this_diff = ll->parent_map;
 473                                 if (!same_diff)
 474                                         same_diff = this_diff;
 475                                 else if (same_diff != this_diff) {
 476                                         has_interesting = 1;
 477                                 }
 478                                 ll = ll->next;
 479                         }
 480                 }
 481
 482                 if (!has_interesting && same_diff != all_mask) {
 483                         /* This hunk is not that interesting after all */
 484                         for (j = hunk_begin; j < hunk_end; j++)
 485                                 sline[j].flag &= ~mark;
 486                 }
 487                 i = hunk_end;
 488         }
 489
 490         has_interesting = give_context(sline, cnt, num_parent);
 491         return has_interesting;
 492 }
 493
 494 static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
 495 {
 496         l0 = sline[l0].p_lno[n];
 497         l1 = sline[l1].p_lno[n];
 498         printf(" -%lu,%lu", l0, l1-l0-null_context);
 499 }
 500
 501 static int hunk_comment_line(const char *bol)
 502 {
 503         int ch;
 504
 505         if (!bol)
 506                 return 0;
 507         ch = *bol & 0xff;
 508         return (isalpha(ch) || ch == '_' || ch == '$');
 509 }
 510
 511 static void show_line_to_eol(const char *line, int len, const char *reset)
 512 {
 513         int saw_cr_at_eol = 0;
 514         if (len < 0)
 515                 len = strlen(line);
 516         saw_cr_at_eol = (len && line[len-1] == '\r');
 517
 518         printf("%.*s%s%s\n", len - saw_cr_at_eol, line,
 519                reset,
 520                saw_cr_at_eol ? "\r" : "");
 521 }
 522
 523 static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 524                        int use_color)
 525 {
 526         unsigned long mark = (1UL<<num_parent);
 527         unsigned long no_pre_delete = (2UL<<num_parent);
 528         int i;
 529         unsigned long lno = 0;
 530         const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
 531         const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
 532         const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
 533         const char *c_plain = diff_get_color(use_color, DIFF_PLAIN);
 534         const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 535
 536         if (!cnt)
 537                 return; /* result deleted */
 538
 539         while (1) {
 540                 struct sline *sl = &sline[lno];
 541                 unsigned long hunk_end;
 542                 unsigned long rlines;
 543                 const char *hunk_comment = NULL;
 544                 unsigned long null_context = 0;
 545
 546                 while (lno <= cnt && !(sline[lno].flag & mark)) {
 547                         if (hunk_comment_line(sline[lno].bol))
 548                                 hunk_comment = sline[lno].bol;
 549                         lno++;
 550                 }
 551                 if (cnt < lno)
 552                         break;
 553                 else {
 554                         for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
 555                                 if (!(sline[hunk_end].flag & mark))
 556                                         break;
 557                 }
 558                 rlines = hunk_end - lno;
 559                 if (cnt < hunk_end)
 560                         rlines--; /* pointing at the last delete hunk */
 561
 562                 if (!context) {
 563                         /*
 564                          * Even when running with --unified=0, all
 565                          * lines in the hunk needs to be processed in
 566                          * the loop below in order to show the
 567                          * deletion recorded in lost_head.  However,
 568                          * we do not want to show the resulting line
 569                          * with all blank context markers in such a
 570                          * case.  Compensate.
 571                          */
 572                         unsigned long j;
 573                         for (j = lno; j < hunk_end; j++)
 574                                 if (!(sline[j].flag & (mark-1)))
 575                                         null_context++;
 576                         rlines -= null_context;
 577                 }
 578
 579                 fputs(c_frag, stdout);
 580                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 581                 for (i = 0; i < num_parent; i++)
 582                         show_parent_lno(sline, lno, hunk_end, i, null_context);
 583                 printf(" +%lu,%lu ", lno+1, rlines);
 584                 for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 585
 586                 if (hunk_comment) {
 587                         int comment_end = 0;
 588                         for (i = 0; i < 40; i++) {
 589                                 int ch = hunk_comment[i] & 0xff;
 590                                 if (!ch || ch == '\n')
 591                                         break;
 592                                 if (!isspace(ch))
 593                                     comment_end = i;
 594                         }
 595                         if (comment_end)
 596                                 putchar(' ');
 597                         for (i = 0; i < comment_end; i++)
 598                                 putchar(hunk_comment[i]);
 599                 }
 600
 601                 printf("%s\n", c_reset);
 602                 while (lno < hunk_end) {
 603                         struct lline *ll;
 604                         int j;
 605                         unsigned long p_mask;
 606                         sl = &sline[lno++];
 607                         ll = (sl->flag & no_pre_delete) ? NULL : sl->lost_head;
 608                         while (ll) {
 609                                 fputs(c_old, stdout);
 610                                 for (j = 0; j < num_parent; j++) {
 611                                         if (ll->parent_map & (1UL<<j))
 612                                                 putchar('-');
 613                                         else
 614                                                 putchar(' ');
 615                                 }
 616                                 show_line_to_eol(ll->line, -1, c_reset);
 617                                 ll = ll->next;
 618                         }
 619                         if (cnt < lno)
 620                                 break;
 621                         p_mask = 1;
 622                         if (!(sl->flag & (mark-1))) {
 623                                 /*
 624                                  * This sline was here to hang the
 625                                  * lost lines in front of it.
 626                                  */
 627                                 if (!context)
 628                                         continue;
 629                                 fputs(c_plain, stdout);
 630                         }
 631                         else
 632                                 fputs(c_new, stdout);
 633                         for (j = 0; j < num_parent; j++) {
 634                                 if (p_mask & sl->flag)
 635                                         putchar('+');
 636                                 else
 637                                         putchar(' ');
 638                                 p_mask <<= 1;
 639                         }
 640                         show_line_to_eol(sl->bol, sl->len, c_reset);
 641                 }
 642         }
 643 }
 644
 645 static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 646                                int i, int j)
 647 {
 648         /* We have already examined parent j and we know parent i
 649          * and parent j are the same, so reuse the combined result
 650          * of parent j for parent i.
 651          */
 652         unsigned long lno, imask, jmask;
 653         imask = (1UL<<i);
 654         jmask = (1UL<<j);
 655
 656         for (lno = 0; lno <= cnt; lno++) {
 657                 struct lline *ll = sline->lost_head;
 658                 sline->p_lno[i] = sline->p_lno[j];
 659                 while (ll) {
 660                         if (ll->parent_map & jmask)
 661                                 ll->parent_map |= imask;
 662                         ll = ll->next;
 663                 }
 664                 if (sline->flag & jmask)
 665                         sline->flag |= imask;
 666                 sline++;
 667         }
 668         /* the overall size of the file (sline[cnt]) */
 669         sline->p_lno[i] = sline->p_lno[j];
 670 }
 671
 672 static void dump_quoted_path(const char *head,
 673                              const char *prefix,
 674                              const char *path,
 675                              const char *c_meta, const char *c_reset)
 676 {
 677         static struct strbuf buf = STRBUF_INIT;
 678
 679         strbuf_reset(&buf);
 680         strbuf_addstr(&buf, c_meta);
 681         strbuf_addstr(&buf, head);
 682         quote_two_c_style(&buf, prefix, path, 0);
 683         strbuf_addstr(&buf, c_reset);
 684         puts(buf.buf);
 685 }
 686
 687 static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 688                             int dense, struct rev_info *rev)
 689 {
 690         struct diff_options *opt = &rev->diffopt;
 691         unsigned long result_size, cnt, lno;
 692         char *result, *cp;
 693         struct sline *sline; /* survived lines */
 694         int mode_differs = 0;
 695         int i, show_hunks;
 696         int working_tree_file = is_null_sha1(elem->sha1);
 697         int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
 698         mmfile_t result_file;
 699
 700         context = opt->context;
 701         /* Read the result of merge first */
 702         if (!working_tree_file)
 703                 result = grab_blob(elem->sha1, elem->mode, &result_size);
 704         else {
 705                 /* Used by diff-tree to read from the working tree */
 706                 struct stat st;
 707                 int fd = -1;
 708
 709                 if (lstat(elem->path, &st) < 0)
 710                         goto deleted_file;
 711
 712                 if (S_ISLNK(st.st_mode)) {
 713                         size_t len = xsize_t(st.st_size);
 714                         result_size = len;
 715                         result = xmalloc(len + 1);
 716                         if (result_size != readlink(elem->path, result, len)) {
 717                                 error("readlink(%s): %s", elem->path,
 718                                       strerror(errno));
 719                                 return;
 720                         }
 721                         result[len] = 0;
 722                         elem->mode = canon_mode(st.st_mode);
 723                 } else if (S_ISDIR(st.st_mode)) {
 724                         unsigned char sha1[20];
 725                         if (resolve_gitlink_ref(elem->path, "HEAD", sha1) < 0)
 726                                 result = grab_blob(elem->sha1, elem->mode, &result_size);
 727                         else
 728                                 result = grab_blob(sha1, elem->mode, &result_size);
 729                 } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
 730                         size_t len = xsize_t(st.st_size);
 731                         ssize_t done;
 732                         int is_file, i;
 733
 734                         elem->mode = canon_mode(st.st_mode);
 735                         /* if symlinks don't work, assume symlink if all parents
 736                          * are symlinks
 737                          */
 738                         is_file = has_symlinks;
 739                         for (i = 0; !is_file && i < num_parent; i++)
 740                                 is_file = !S_ISLNK(elem->parent[i].mode);
 741                         if (!is_file)
 742                                 elem->mode = canon_mode(S_IFLNK);
 743
 744                         result_size = len;
 745                         result = xmalloc(len + 1);
 746
 747                         done = read_in_full(fd, result, len);
 748                         if (done < 0)
 749                                 die("read error '%s'", elem->path);
 750                         else if (done < len)
 751                                 die("early EOF '%s'", elem->path);
 752
 753                         result[len] = 0;
 754
 755                         /* If not a fake symlink, apply filters, e.g. autocrlf */
 756                         if (is_file) {
 757                                 struct strbuf buf;
 758
 759                                 strbuf_init(&buf, 0);
 760                                 if (convert_to_git(elem->path, result, len, &buf, safe_crlf)) {
 761                                         free(result);
 762                                         result = strbuf_detach(&buf, &len);
 763                                         result_size = len;
 764                                 }
 765                         }
 766                 }
 767                 else {
 768                 deleted_file:
 769                         result_size = 0;
 770                         elem->mode = 0;
 771                         result = xcalloc(1, 1);
 772                 }
 773
 774                 if (0 <= fd)
 775                         close(fd);
 776         }
 777
 778         for (cnt = 0, cp = result; cp < result + result_size; cp++) {
 779                 if (*cp == '\n')
 780                         cnt++;
 781         }
 782         if (result_size && result[result_size-1] != '\n')
 783                 cnt++; /* incomplete line */
 784
 785         sline = xcalloc(cnt+2, sizeof(*sline));
 786         sline[0].bol = result;
 787         for (lno = 0; lno <= cnt + 1; lno++) {
 788                 sline[lno].lost_tail = &sline[lno].lost_head;
 789                 sline[lno].flag = 0;
 790         }
 791         for (lno = 0, cp = result; cp < result + result_size; cp++) {
 792                 if (*cp == '\n') {
 793                         sline[lno].len = cp - sline[lno].bol;
 794                         lno++;
 795                         if (lno < cnt)
 796                                 sline[lno].bol = cp + 1;
 797                 }
 798         }
 799         if (result_size && result[result_size-1] != '\n')
 800                 sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
 801
 802         result_file.ptr = result;
 803         result_file.size = result_size;
 804
 805         /* Even p_lno[cnt+1] is valid -- that is for the end line number
 806          * for deletion hunk at the end.
 807          */
 808         sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
 809         for (lno = 0; lno <= cnt; lno++)
 810                 sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
 811
 812         for (i = 0; i < num_parent; i++) {
 813                 int j;
 814                 for (j = 0; j < i; j++) {
 815                         if (!hashcmp(elem->parent[i].sha1,
 816                                      elem->parent[j].sha1)) {
 817                                 reuse_combine_diff(sline, cnt, i, j);
 818                                 break;
 819                         }
 820                 }
 821                 if (i <= j)
 822                         combine_diff(elem->parent[i].sha1,
 823                                      elem->parent[i].mode,
 824                                      &result_file, sline,
 825                                      cnt, i, num_parent);
 826                 if (elem->parent[i].mode != elem->mode)
 827                         mode_differs = 1;
 828         }
 829
 830         show_hunks = make_hunks(sline, cnt, num_parent, dense);
 831
 832         if (show_hunks || mode_differs || working_tree_file) {
 833                 const char *abb;
 834                 int use_color = DIFF_OPT_TST(opt, COLOR_DIFF);
 835                 const char *c_meta = diff_get_color(use_color, DIFF_METAINFO);
 836                 const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 837                 int added = 0;
 838                 int deleted = 0;
 839
 840                 if (rev->loginfo && !rev->no_commit_id)
 841                         show_log(rev);
 842                 dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
 843                                  "", elem->path, c_meta, c_reset);
 844                 printf("%sindex ", c_meta);
 845                 for (i = 0; i < num_parent; i++) {
 846                         abb = find_unique_abbrev(elem->parent[i].sha1,
 847                                                  abbrev);
 848                         printf("%s%s", i ? "," : "", abb);
 849                 }
 850                 abb = find_unique_abbrev(elem->sha1, abbrev);
 851                 printf("..%s%s\n", abb, c_reset);
 852
 853                 if (mode_differs) {
 854                         deleted = !elem->mode;
 855
 856                         /* We say it was added if nobody had it */
 857                         added = !deleted;
 858                         for (i = 0; added && i < num_parent; i++)
 859                                 if (elem->parent[i].status !=
 860                                     DIFF_STATUS_ADDED)
 861                                         added = 0;
 862                         if (added)
 863                                 printf("%snew file mode %06o",
 864                                        c_meta, elem->mode);
 865                         else {
 866                                 if (deleted)
 867                                         printf("%sdeleted file ", c_meta);
 868                                 printf("mode ");
 869                                 for (i = 0; i < num_parent; i++) {
 870                                         printf("%s%06o", i ? "," : "",
 871                                                elem->parent[i].mode);
 872                                 }
 873                                 if (elem->mode)
 874                                         printf("..%06o", elem->mode);
 875                         }
 876                         printf("%s\n", c_reset);
 877                 }
 878                 if (added)
 879                         dump_quoted_path("--- ", "", "/dev/null",
 880                                          c_meta, c_reset);
 881                 else
 882                         dump_quoted_path("--- ", opt->a_prefix, elem->path,
 883                                          c_meta, c_reset);
 884                 if (deleted)
 885                         dump_quoted_path("+++ ", "", "/dev/null",
 886                                          c_meta, c_reset);
 887                 else
 888                         dump_quoted_path("+++ ", opt->b_prefix, elem->path,
 889                                          c_meta, c_reset);
 890                 dump_sline(sline, cnt, num_parent,
 891                            DIFF_OPT_TST(opt, COLOR_DIFF));
 892         }
 893         free(result);
 894
 895         for (lno = 0; lno < cnt; lno++) {
 896                 if (sline[lno].lost_head) {
 897                         struct lline *ll = sline[lno].lost_head;
 898                         while (ll) {
 899                                 struct lline *tmp = ll;
 900                                 ll = ll->next;
 901                                 free(tmp);
 902                         }
 903                 }
 904         }
 905         free(sline[0].p_lno);
 906         free(sline);
 907 }
 908
 909 #define COLONS "::::::::::::::::::::::::::::::::"
 910
 911 static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
 912 {
 913         struct diff_options *opt = &rev->diffopt;
 914         int i, offset;
 915         const char *prefix;
 916         int line_termination, inter_name_termination;
 917
 918         line_termination = opt->line_termination;
 919         inter_name_termination = '\t';
 920         if (!line_termination)
 921                 inter_name_termination = 0;
 922
 923         if (rev->loginfo && !rev->no_commit_id)
 924                 show_log(rev);
 925
 926         if (opt->output_format & DIFF_FORMAT_RAW) {
 927                 offset = strlen(COLONS) - num_parent;
 928                 if (offset < 0)
 929                         offset = 0;
 930                 prefix = COLONS + offset;
 931
 932                 /* Show the modes */
 933                 for (i = 0; i < num_parent; i++) {
 934                         printf("%s%06o", prefix, p->parent[i].mode);
 935                         prefix = " ";
 936                 }
 937                 printf("%s%06o", prefix, p->mode);
 938
 939                 /* Show sha1's */
 940                 for (i = 0; i < num_parent; i++)
 941                         printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
 942                                                          opt->abbrev));
 943                 printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
 944         }
 945
 946         if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
 947                 for (i = 0; i < num_parent; i++)
 948                         putchar(p->parent[i].status);
 949                 putchar(inter_name_termination);
 950         }
 951
 952         write_name_quoted(p->path, stdout, line_termination);
 953 }
 954
 955 void show_combined_diff(struct combine_diff_path *p,
 956                        int num_parent,
 957                        int dense,
 958                        struct rev_info *rev)
 959 {
 960         struct diff_options *opt = &rev->diffopt;
 961         if (!p->len)
 962                 return;
 963         if (opt->output_format & (DIFF_FORMAT_RAW |
 964                                   DIFF_FORMAT_NAME |
 965                                   DIFF_FORMAT_NAME_STATUS))
 966                 show_raw_diff(p, num_parent, rev);
 967         else if (opt->output_format & DIFF_FORMAT_PATCH)
 968                 show_patch_diff(p, num_parent, dense, rev);
 969 }
 970
 971 void diff_tree_combined(const unsigned char *sha1,
 972                         const unsigned char parent[][20],
 973                         int num_parent,
 974                         int dense,
 975                         struct rev_info *rev)
 976 {
 977         struct diff_options *opt = &rev->diffopt;
 978         struct diff_options diffopts;
 979         struct combine_diff_path *p, *paths = NULL;
 980         int i, num_paths, needsep, show_log_first;
 981
 982         diffopts = *opt;
 983         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
 984         DIFF_OPT_SET(&diffopts, RECURSIVE);
 985         DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
 986
 987         show_log_first = !!rev->loginfo && !rev->no_commit_id;
 988         needsep = 0;
 989         /* find set of paths that everybody touches */
 990         for (i = 0; i < num_parent; i++) {
 991                 /* show stat against the first parent even
 992                  * when doing combined diff.
 993                  */
 994                 int stat_opt = (opt->output_format &
 995                                 (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
 996                 if (i == 0 && stat_opt)
 997                         diffopts.output_format = stat_opt;
 998                 else
 999                         diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
1000                 diff_tree_sha1(parent[i], sha1, "", &diffopts);
1001                 diffcore_std(&diffopts);
1002                 paths = intersect_paths(paths, i, num_parent);
1003
1004                 if (show_log_first && i == 0) {
1005                         show_log(rev);
1006                         if (rev->verbose_header && opt->output_format)
1007                                 putchar(opt->line_termination);
1008                 }
1009                 diff_flush(&diffopts);
1010         }
1011
1012         /* find out surviving paths */
1013         for (num_paths = 0, p = paths; p; p = p->next) {
1014                 if (p->len)
1015                         num_paths++;
1016         }
1017         if (num_paths) {
1018                 if (opt->output_format & (DIFF_FORMAT_RAW |
1019                                           DIFF_FORMAT_NAME |
1020                                           DIFF_FORMAT_NAME_STATUS)) {
1021                         for (p = paths; p; p = p->next) {
1022                                 if (p->len)
1023                                         show_raw_diff(p, num_parent, rev);
1024                         }
1025                         needsep = 1;
1026                 }
1027                 else if (opt->output_format &
1028                          (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
1029                         needsep = 1;
1030                 if (opt->output_format & DIFF_FORMAT_PATCH) {
1031                         if (needsep)
1032                                 putchar(opt->line_termination);
1033                         for (p = paths; p; p = p->next) {
1034                                 if (p->len)
1035                                         show_patch_diff(p, num_parent, dense,
1036                                                         rev);
1037                         }
1038                 }
1039         }
1040
1041         /* Clean things up */
1042         while (paths) {
1043                 struct combine_diff_path *tmp = paths;
1044                 paths = paths->next;
1045                 free(tmp);
1046         }
1047 }
1048
1049 void diff_tree_combined_merge(const unsigned char *sha1,
1050                              int dense, struct rev_info *rev)
1051 {
1052         int num_parent;
1053         const unsigned char (*parent)[20];
1054         struct commit *commit = lookup_commit(sha1);
1055         struct commit_list *parents;
1056
1057         /* count parents */
1058         for (parents = commit->parents, num_parent = 0;
1059              parents;
1060              parents = parents->next, num_parent++)
1061                 ; /* nothing */
1062
1063         parent = xmalloc(num_parent * sizeof(*parent));
1064         for (parents = commit->parents, num_parent = 0;
1065              parents;
1066              parents = parents->next, num_parent++)
1067                 hashcpy((unsigned char*)(parent + num_parent),
1068                         parents->item->object.sha1);
1069         diff_tree_combined(sha1, parent, num_parent, dense, rev);
1070 }