combine-diff.con commit Merge git://git.kernel.org/pub/scm/gitk/gitk (d69dc37)
   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
   8static int uninteresting(struct diff_filepair *p)
   9{
  10        if (diff_unmodified_pair(p))
  11                return 1;
  12        return 0;
  13}
  14
  15static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
  16{
  17        struct diff_queue_struct *q = &diff_queued_diff;
  18        struct combine_diff_path *p;
  19        int i;
  20
  21        if (!n) {
  22                struct combine_diff_path *list = NULL, **tail = &list;
  23                for (i = 0; i < q->nr; i++) {
  24                        int len;
  25                        const char *path;
  26                        if (uninteresting(q->queue[i]))
  27                                continue;
  28                        path = q->queue[i]->two->path;
  29                        len = strlen(path);
  30                        p = xmalloc(combine_diff_path_size(num_parent, len));
  31                        p->path = (char*) &(p->parent[num_parent]);
  32                        memcpy(p->path, path, len);
  33                        p->path[len] = 0;
  34                        p->len = len;
  35                        p->next = NULL;
  36                        memset(p->parent, 0,
  37                               sizeof(p->parent[0]) * num_parent);
  38
  39                        memcpy(p->sha1, q->queue[i]->two->sha1, 20);
  40                        p->mode = q->queue[i]->two->mode;
  41                        memcpy(p->parent[n].sha1, q->queue[i]->one->sha1, 20);
  42                        p->parent[n].mode = q->queue[i]->one->mode;
  43                        p->parent[n].status = q->queue[i]->status;
  44                        *tail = p;
  45                        tail = &p->next;
  46                }
  47                return list;
  48        }
  49
  50        for (p = curr; p; p = p->next) {
  51                int found = 0;
  52                if (!p->len)
  53                        continue;
  54                for (i = 0; i < q->nr; i++) {
  55                        const char *path;
  56                        int len;
  57
  58                        if (uninteresting(q->queue[i]))
  59                                continue;
  60                        path = q->queue[i]->two->path;
  61                        len = strlen(path);
  62                        if (len == p->len && !memcmp(path, p->path, len)) {
  63                                found = 1;
  64                                memcpy(p->parent[n].sha1,
  65                                       q->queue[i]->one->sha1, 20);
  66                                p->parent[n].mode = q->queue[i]->one->mode;
  67                                p->parent[n].status = q->queue[i]->status;
  68                                break;
  69                        }
  70                }
  71                if (!found)
  72                        p->len = 0;
  73        }
  74        return curr;
  75}
  76
  77/* Lines lost from parent */
  78struct lline {
  79        struct lline *next;
  80        int len;
  81        unsigned long parent_map;
  82        char line[FLEX_ARRAY];
  83};
  84
  85/* Lines surviving in the merge result */
  86struct sline {
  87        struct lline *lost_head, **lost_tail;
  88        char *bol;
  89        int len;
  90        /* bit 0 up to (N-1) are on if the parent has this line (i.e.
  91         * we did not change it).
  92         * bit N is used for "interesting" lines, including context.
  93         */
  94        unsigned long flag;
  95        unsigned long *p_lno;
  96};
  97
  98static char *grab_blob(const unsigned char *sha1, unsigned long *size)
  99{
 100        char *blob;
 101        char type[20];
 102        if (!memcmp(sha1, null_sha1, 20)) {
 103                /* deleted blob */
 104                *size = 0;
 105                return xcalloc(1, 1);
 106        }
 107        blob = read_sha1_file(sha1, type, size);
 108        if (strcmp(type, blob_type))
 109                die("object '%s' is not a blob!", sha1_to_hex(sha1));
 110        return blob;
 111}
 112
 113#define TMPPATHLEN 50
 114#define MAXLINELEN 10240
 115
 116static void write_to_temp_file(char *tmpfile, void *blob, unsigned long size)
 117{
 118        int fd = git_mkstemp(tmpfile, TMPPATHLEN, ".diff_XXXXXX");
 119        if (fd < 0)
 120                die("unable to create temp-file");
 121        if (write(fd, blob, size) != size)
 122                die("unable to write temp-file");
 123        close(fd);
 124}
 125
 126static void write_temp_blob(char *tmpfile, const unsigned char *sha1)
 127{
 128        unsigned long size;
 129        void *blob;
 130        blob = grab_blob(sha1, &size);
 131        write_to_temp_file(tmpfile, blob, size);
 132        free(blob);
 133}
 134
 135static int parse_num(char **cp_p, unsigned int *num_p)
 136{
 137        char *cp = *cp_p;
 138        unsigned int num = 0;
 139        int read_some;
 140
 141        while ('0' <= *cp && *cp <= '9')
 142                num = num * 10 + *cp++ - '0';
 143        if (!(read_some = cp - *cp_p))
 144                return -1;
 145        *cp_p = cp;
 146        *num_p = num;
 147        return 0;
 148}
 149
 150static int parse_hunk_header(char *line, int len,
 151                             unsigned int *ob, unsigned int *on,
 152                             unsigned int *nb, unsigned int *nn)
 153{
 154        char *cp;
 155        cp = line + 4;
 156        if (parse_num(&cp, ob)) {
 157        bad_line:
 158                return error("malformed diff output: %s", line);
 159        }
 160        if (*cp == ',') {
 161                cp++;
 162                if (parse_num(&cp, on))
 163                        goto bad_line;
 164        }
 165        else
 166                *on = 1;
 167        if (*cp++ != ' ' || *cp++ != '+')
 168                goto bad_line;
 169        if (parse_num(&cp, nb))
 170                goto bad_line;
 171        if (*cp == ',') {
 172                cp++;
 173                if (parse_num(&cp, nn))
 174                        goto bad_line;
 175        }
 176        else
 177                *nn = 1;
 178        return -!!memcmp(cp, " @@", 3);
 179}
 180
 181static void append_lost(struct sline *sline, int n, const char *line)
 182{
 183        struct lline *lline;
 184        int len = strlen(line);
 185        unsigned long this_mask = (1UL<<n);
 186        if (line[len-1] == '\n')
 187                len--;
 188
 189        /* Check to see if we can squash things */
 190        if (sline->lost_head) {
 191                struct lline *last_one = NULL;
 192                /* We cannot squash it with earlier one */
 193                for (lline = sline->lost_head;
 194                     lline;
 195                     lline = lline->next)
 196                        if (lline->parent_map & this_mask)
 197                                last_one = lline;
 198                lline = last_one ? last_one->next : sline->lost_head;
 199                while (lline) {
 200                        if (lline->len == len &&
 201                            !memcmp(lline->line, line, len)) {
 202                                lline->parent_map |= this_mask;
 203                                return;
 204                        }
 205                        lline = lline->next;
 206                }
 207        }
 208
 209        lline = xmalloc(sizeof(*lline) + len + 1);
 210        lline->len = len;
 211        lline->next = NULL;
 212        lline->parent_map = this_mask;
 213        memcpy(lline->line, line, len);
 214        lline->line[len] = 0;
 215        *sline->lost_tail = lline;
 216        sline->lost_tail = &lline->next;
 217}
 218
 219static void combine_diff(const unsigned char *parent, const char *ourtmp,
 220                         struct sline *sline, int cnt, int n, int num_parent)
 221{
 222        FILE *in;
 223        char parent_tmp[TMPPATHLEN];
 224        char cmd[TMPPATHLEN * 2 + 1024];
 225        char line[MAXLINELEN];
 226        unsigned int lno, ob, on, nb, nn, p_lno;
 227        unsigned long nmask = (1UL << n);
 228        struct sline *lost_bucket = NULL;
 229
 230        if (!cnt)
 231                return; /* result deleted */
 232
 233        write_temp_blob(parent_tmp, parent);
 234        sprintf(cmd, "diff --unified=0 -La/x -Lb/x '%s' '%s'",
 235                parent_tmp, ourtmp);
 236        in = popen(cmd, "r");
 237        if (!in)
 238                die("cannot spawn %s", cmd);
 239
 240        lno = 1;
 241        while (fgets(line, sizeof(line), in) != NULL) {
 242                int len = strlen(line);
 243                if (5 < len && !memcmp("@@ -", line, 4)) {
 244                        if (parse_hunk_header(line, len,
 245                                              &ob, &on, &nb, &nn))
 246                                break;
 247                        lno = nb;
 248                        if (!nb)
 249                                /* @@ -1,2 +0,0 @@ to remove the
 250                                 * first two lines...
 251                                 */
 252                                nb = 1;
 253                        if (nn == 0)
 254                                /* @@ -X,Y +N,0 @@ removed Y lines
 255                                 * that would have come *after* line N
 256                                 * in the result.  Our lost buckets hang
 257                                 * to the line after the removed lines,
 258                                 */
 259                                lost_bucket = &sline[nb];
 260                        else
 261                                lost_bucket = &sline[nb-1];
 262                        if (!sline[nb-1].p_lno)
 263                                sline[nb-1].p_lno =
 264                                        xcalloc(num_parent,
 265                                                sizeof(unsigned long));
 266                        sline[nb-1].p_lno[n] = ob;
 267                        continue;
 268                }
 269                if (!lost_bucket)
 270                        continue; /* not in any hunk yet */
 271                switch (line[0]) {
 272                case '-':
 273                        append_lost(lost_bucket, n, line+1);
 274                        break;
 275                case '+':
 276                        sline[lno-1].flag |= nmask;
 277                        lno++;
 278                        break;
 279                }
 280        }
 281        fclose(in);
 282        unlink(parent_tmp);
 283
 284        /* Assign line numbers for this parent.
 285         *
 286         * sline[lno].p_lno[n] records the first line number
 287         * (counting from 1) for parent N if the final hunk display
 288         * started by showing sline[lno] (possibly showing the lost
 289         * lines attached to it first).
 290         */
 291        for (lno = 0,  p_lno = 1; lno < cnt; lno++) {
 292                struct lline *ll;
 293                sline[lno].p_lno[n] = p_lno;
 294
 295                /* How many lines would this sline advance the p_lno? */
 296                ll = sline[lno].lost_head;
 297                while (ll) {
 298                        if (ll->parent_map & nmask)
 299                                p_lno++; /* '-' means parent had it */
 300                        ll = ll->next;
 301                }
 302                if (!(sline[lno].flag & nmask))
 303                        p_lno++; /* no '+' means parent had it */
 304        }
 305        sline[lno].p_lno[n] = p_lno; /* trailer */
 306}
 307
 308static unsigned long context = 3;
 309static char combine_marker = '@';
 310
 311static int interesting(struct sline *sline, unsigned long all_mask)
 312{
 313        /* If some parents lost lines here, or if we have added to
 314         * some parent, it is interesting.
 315         */
 316        return ((sline->flag & all_mask) || sline->lost_head);
 317}
 318
 319static unsigned long adjust_hunk_tail(struct sline *sline,
 320                                      unsigned long all_mask,
 321                                      unsigned long hunk_begin,
 322                                      unsigned long i)
 323{
 324        /* i points at the first uninteresting line.  If the last line
 325         * of the hunk was interesting only because it has some
 326         * deletion, then it is not all that interesting for the
 327         * purpose of giving trailing context lines.  This is because
 328         * we output '-' line and then unmodified sline[i-1] itself in
 329         * that case which gives us one extra context line.
 330         */
 331        if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
 332                i--;
 333        return i;
 334}
 335
 336static unsigned long find_next(struct sline *sline,
 337                               unsigned long mark,
 338                               unsigned long i,
 339                               unsigned long cnt,
 340                               int uninteresting)
 341{
 342        /* We have examined up to i-1 and are about to look at i.
 343         * Find next interesting or uninteresting line.  Here,
 344         * "interesting" does not mean interesting(), but marked by
 345         * the give_context() function below (i.e. it includes context
 346         * lines that are not interesting to interesting() function
 347         * that are surrounded by interesting() ones.
 348         */
 349        while (i < cnt)
 350                if (uninteresting
 351                    ? !(sline[i].flag & mark)
 352                    : (sline[i].flag & mark))
 353                        return i;
 354                else
 355                        i++;
 356        return cnt;
 357}
 358
 359static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 360{
 361        unsigned long all_mask = (1UL<<num_parent) - 1;
 362        unsigned long mark = (1UL<<num_parent);
 363        unsigned long i;
 364
 365        /* Two groups of interesting lines may have a short gap of
 366         * unintersting lines.  Connect such groups to give them a
 367         * bit of context.
 368         *
 369         * We first start from what the interesting() function says,
 370         * and mark them with "mark", and paint context lines with the
 371         * mark.  So interesting() would still say false for such context
 372         * lines but they are treated as "interesting" in the end.
 373         */
 374        i = find_next(sline, mark, 0, cnt, 0);
 375        if (cnt <= i)
 376                return 0;
 377
 378        while (i < cnt) {
 379                unsigned long j = (context < i) ? (i - context) : 0;
 380                unsigned long k;
 381
 382                /* Paint a few lines before the first interesting line. */
 383                while (j < i)
 384                        sline[j++].flag |= mark;
 385
 386        again:
 387                /* we know up to i is to be included.  where does the
 388                 * next uninteresting one start?
 389                 */
 390                j = find_next(sline, mark, i, cnt, 1);
 391                if (cnt <= j)
 392                        break; /* the rest are all interesting */
 393
 394                /* lookahead context lines */
 395                k = find_next(sline, mark, j, cnt, 0);
 396                j = adjust_hunk_tail(sline, all_mask, i, j);
 397
 398                if (k < j + context) {
 399                        /* k is interesting and [j,k) are not, but
 400                         * paint them interesting because the gap is small.
 401                         */
 402                        while (j < k)
 403                                sline[j++].flag |= mark;
 404                        i = k;
 405                        goto again;
 406                }
 407
 408                /* j is the first uninteresting line and there is
 409                 * no overlap beyond it within context lines.  Paint
 410                 * the trailing edge a bit.
 411                 */
 412                i = k;
 413                k = (j + context < cnt) ? j + context : cnt;
 414                while (j < k)
 415                        sline[j++].flag |= mark;
 416        }
 417        return 1;
 418}
 419
 420static int make_hunks(struct sline *sline, unsigned long cnt,
 421                       int num_parent, int dense)
 422{
 423        unsigned long all_mask = (1UL<<num_parent) - 1;
 424        unsigned long mark = (1UL<<num_parent);
 425        unsigned long i;
 426        int has_interesting = 0;
 427
 428        for (i = 0; i < cnt; i++) {
 429                if (interesting(&sline[i], all_mask))
 430                        sline[i].flag |= mark;
 431                else
 432                        sline[i].flag &= ~mark;
 433        }
 434        if (!dense)
 435                return give_context(sline, cnt, num_parent);
 436
 437        /* Look at each hunk, and if we have changes from only one
 438         * parent, or the changes are the same from all but one
 439         * parent, mark that uninteresting.
 440         */
 441        i = 0;
 442        while (i < cnt) {
 443                unsigned long j, hunk_begin, hunk_end;
 444                unsigned long same_diff;
 445                while (i < cnt && !(sline[i].flag & mark))
 446                        i++;
 447                if (cnt <= i)
 448                        break; /* No more interesting hunks */
 449                hunk_begin = i;
 450                for (j = i + 1; j < cnt; j++) {
 451                        if (!(sline[j].flag & mark)) {
 452                                /* Look beyond the end to see if there
 453                                 * is an interesting line after this
 454                                 * hunk within context span.
 455                                 */
 456                                unsigned long la; /* lookahead */
 457                                int contin = 0;
 458                                la = adjust_hunk_tail(sline, all_mask,
 459                                                     hunk_begin, j);
 460                                la = (la + context < cnt) ?
 461                                        (la + context) : cnt;
 462                                while (j <= --la) {
 463                                        if (sline[la].flag & mark) {
 464                                                contin = 1;
 465                                                break;
 466                                        }
 467                                }
 468                                if (!contin)
 469                                        break;
 470                                j = la;
 471                        }
 472                }
 473                hunk_end = j;
 474
 475                /* [i..hunk_end) are interesting.  Now is it really
 476                 * interesting?  We check if there are only two versions
 477                 * and the result matches one of them.  That is, we look
 478                 * at:
 479                 *   (+) line, which records lines added to which parents;
 480                 *       this line appears in the result.
 481                 *   (-) line, which records from what parents the line
 482                 *       was removed; this line does not appear in the result.
 483                 * then check the set of parents the result has difference
 484                 * from, from all lines.  If there are lines that has
 485                 * different set of parents that the result has differences
 486                 * from, that means we have more than two versions.
 487                 *
 488                 * Even when we have only two versions, if the result does
 489                 * not match any of the parents, the it should be considered
 490                 * interesting.  In such a case, we would have all '+' line.
 491                 * After passing the above "two versions" test, that would
 492                 * appear as "the same set of parents" to be "all parents".
 493                 */
 494                same_diff = 0;
 495                has_interesting = 0;
 496                for (j = i; j < hunk_end && !has_interesting; j++) {
 497                        unsigned long this_diff = sline[j].flag & all_mask;
 498                        struct lline *ll = sline[j].lost_head;
 499                        if (this_diff) {
 500                                /* This has some changes.  Is it the
 501                                 * same as others?
 502                                 */
 503                                if (!same_diff)
 504                                        same_diff = this_diff;
 505                                else if (same_diff != this_diff) {
 506                                        has_interesting = 1;
 507                                        break;
 508                                }
 509                        }
 510                        while (ll && !has_interesting) {
 511                                /* Lost this line from these parents;
 512                                 * who are they?  Are they the same?
 513                                 */
 514                                this_diff = ll->parent_map;
 515                                if (!same_diff)
 516                                        same_diff = this_diff;
 517                                else if (same_diff != this_diff) {
 518                                        has_interesting = 1;
 519                                }
 520                                ll = ll->next;
 521                        }
 522                }
 523
 524                if (!has_interesting && same_diff != all_mask) {
 525                        /* This hunk is not that interesting after all */
 526                        for (j = hunk_begin; j < hunk_end; j++)
 527                                sline[j].flag &= ~mark;
 528                }
 529                i = hunk_end;
 530        }
 531
 532        has_interesting = give_context(sline, cnt, num_parent);
 533        return has_interesting;
 534}
 535
 536static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, unsigned long cnt, int n)
 537{
 538        l0 = sline[l0].p_lno[n];
 539        l1 = sline[l1].p_lno[n];
 540        printf(" -%lu,%lu", l0, l1-l0);
 541}
 542
 543static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent)
 544{
 545        unsigned long mark = (1UL<<num_parent);
 546        int i;
 547        unsigned long lno = 0;
 548
 549        if (!cnt)
 550                return; /* result deleted */
 551
 552        while (1) {
 553                struct sline *sl = &sline[lno];
 554                int hunk_end;
 555                while (lno < cnt && !(sline[lno].flag & mark))
 556                        lno++;
 557                if (cnt <= lno)
 558                        break;
 559                for (hunk_end = lno + 1; hunk_end < cnt; hunk_end++)
 560                        if (!(sline[hunk_end].flag & mark))
 561                                break;
 562                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 563                for (i = 0; i < num_parent; i++)
 564                        show_parent_lno(sline, lno, hunk_end, cnt, i);
 565                printf(" +%lu,%lu ", lno+1, hunk_end-lno);
 566                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 567                putchar('\n');
 568                while (lno < hunk_end) {
 569                        struct lline *ll;
 570                        int j;
 571                        unsigned long p_mask;
 572                        sl = &sline[lno++];
 573                        ll = sl->lost_head;
 574                        while (ll) {
 575                                for (j = 0; j < num_parent; j++) {
 576                                        if (ll->parent_map & (1UL<<j))
 577                                                putchar('-');
 578                                        else
 579                                                putchar(' ');
 580                                }
 581                                puts(ll->line);
 582                                ll = ll->next;
 583                        }
 584                        p_mask = 1;
 585                        for (j = 0; j < num_parent; j++) {
 586                                if (p_mask & sl->flag)
 587                                        putchar('+');
 588                                else
 589                                        putchar(' ');
 590                                p_mask <<= 1;
 591                        }
 592                        printf("%.*s\n", sl->len, sl->bol);
 593                }
 594        }
 595}
 596
 597static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 598                               int i, int j)
 599{
 600        /* We have already examined parent j and we know parent i
 601         * and parent j are the same, so reuse the combined result
 602         * of parent j for parent i.
 603         */
 604        unsigned long lno, imask, jmask;
 605        imask = (1UL<<i);
 606        jmask = (1UL<<j);
 607
 608        for (lno = 0; lno < cnt; lno++) {
 609                struct lline *ll = sline->lost_head;
 610                sline->p_lno[i] = sline->p_lno[j];
 611                while (ll) {
 612                        if (ll->parent_map & jmask)
 613                                ll->parent_map |= imask;
 614                        ll = ll->next;
 615                }
 616                if (sline->flag & jmask)
 617                        sline->flag |= imask;
 618                sline++;
 619        }
 620        /* the overall size of the file (sline[cnt]) */
 621        sline->p_lno[i] = sline->p_lno[j];
 622}
 623
 624static int show_patch_diff(struct combine_diff_path *elem, int num_parent,
 625                           int dense, const char *header,
 626                           struct diff_options *opt)
 627{
 628        unsigned long size, cnt, lno;
 629        char *result, *cp, *ep;
 630        struct sline *sline; /* survived lines */
 631        int mode_differs = 0;
 632        int i, show_hunks, shown_header = 0;
 633        char ourtmp_buf[TMPPATHLEN];
 634        char *ourtmp = ourtmp_buf;
 635        int working_tree_file = !memcmp(elem->sha1, null_sha1, 20);
 636        int abbrev = opt->full_index ? 40 : DEFAULT_ABBREV;
 637
 638        /* Read the result of merge first */
 639        if (!working_tree_file) {
 640                result = grab_blob(elem->sha1, &size);
 641                write_to_temp_file(ourtmp, result, size);
 642        }
 643        else {
 644                /* Used by diff-tree to read from the working tree */
 645                struct stat st;
 646                int fd;
 647                ourtmp = elem->path;
 648                if (0 <= (fd = open(ourtmp, O_RDONLY)) &&
 649                    !fstat(fd, &st)) {
 650                        int len = st.st_size;
 651                        int cnt = 0;
 652
 653                        elem->mode = canon_mode(st.st_mode);
 654                        size = len;
 655                        result = xmalloc(len + 1);
 656                        while (cnt < len) {
 657                                int done = xread(fd, result+cnt, len-cnt);
 658                                if (done == 0)
 659                                        break;
 660                                if (done < 0)
 661                                        die("read error '%s'", ourtmp);
 662                                cnt += done;
 663                        }
 664                        result[len] = 0;
 665                }
 666                else {
 667                        /* deleted file */
 668                        size = 0;
 669                        elem->mode = 0;
 670                        result = xmalloc(1);
 671                        result[0] = 0;
 672                        ourtmp = "/dev/null";
 673                }
 674                if (0 <= fd)
 675                        close(fd);
 676        }
 677
 678        for (cnt = 0, cp = result; cp - result < size; cp++) {
 679                if (*cp == '\n')
 680                        cnt++;
 681        }
 682        if (size && result[size-1] != '\n')
 683                cnt++; /* incomplete line */
 684
 685        sline = xcalloc(cnt+1, sizeof(*sline));
 686        ep = result;
 687        sline[0].bol = result;
 688        for (lno = 0; lno <= cnt; lno++) {
 689                sline[lno].lost_tail = &sline[lno].lost_head;
 690                sline[lno].flag = 0;
 691        }
 692        for (lno = 0, cp = result; cp - result < size; cp++) {
 693                if (*cp == '\n') {
 694                        sline[lno].len = cp - sline[lno].bol;
 695                        lno++;
 696                        if (lno < cnt)
 697                                sline[lno].bol = cp + 1;
 698                }
 699        }
 700        if (size && result[size-1] != '\n')
 701                sline[cnt-1].len = size - (sline[cnt-1].bol - result);
 702
 703        sline[0].p_lno = xcalloc((cnt+1) * num_parent, sizeof(unsigned long));
 704        for (lno = 0; lno < cnt; lno++)
 705                sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
 706
 707        for (i = 0; i < num_parent; i++) {
 708                int j;
 709                for (j = 0; j < i; j++) {
 710                        if (!memcmp(elem->parent[i].sha1,
 711                                    elem->parent[j].sha1, 20)) {
 712                                reuse_combine_diff(sline, cnt, i, j);
 713                                break;
 714                        }
 715                }
 716                if (i <= j)
 717                        combine_diff(elem->parent[i].sha1, ourtmp, sline,
 718                                     cnt, i, num_parent);
 719                if (elem->parent[i].mode != elem->mode)
 720                        mode_differs = 1;
 721        }
 722
 723        show_hunks = make_hunks(sline, cnt, num_parent, dense);
 724
 725        if (show_hunks || mode_differs || working_tree_file) {
 726                const char *abb;
 727
 728                if (header) {
 729                        shown_header++;
 730                        printf("%s%c", header, opt->line_termination);
 731                }
 732                printf("diff --%s ", dense ? "cc" : "combined");
 733                if (quote_c_style(elem->path, NULL, NULL, 0))
 734                        quote_c_style(elem->path, NULL, stdout, 0);
 735                else
 736                        printf("%s", elem->path);
 737                putchar('\n');
 738                printf("index ");
 739                for (i = 0; i < num_parent; i++) {
 740                        abb = find_unique_abbrev(elem->parent[i].sha1,
 741                                                 abbrev);
 742                        printf("%s%s", i ? "," : "", abb);
 743                }
 744                abb = find_unique_abbrev(elem->sha1, abbrev);
 745                printf("..%s\n", abb);
 746
 747                if (mode_differs) {
 748                        int added = !!elem->mode;
 749                        for (i = 0; added && i < num_parent; i++)
 750                                if (elem->parent[i].status !=
 751                                    DIFF_STATUS_ADDED)
 752                                        added = 0;
 753                        if (added)
 754                                printf("new file mode %06o", elem->mode);
 755                        else {
 756                                if (!elem->mode)
 757                                        printf("deleted file ");
 758                                printf("mode ");
 759                                for (i = 0; i < num_parent; i++) {
 760                                        printf("%s%06o", i ? "," : "",
 761                                               elem->parent[i].mode);
 762                                }
 763                                if (elem->mode)
 764                                        printf("..%06o", elem->mode);
 765                        }
 766                        putchar('\n');
 767                }
 768                dump_sline(sline, cnt, num_parent);
 769        }
 770        if (ourtmp == ourtmp_buf)
 771                unlink(ourtmp);
 772        free(result);
 773
 774        for (i = 0; i < cnt; i++) {
 775                if (sline[i].lost_head) {
 776                        struct lline *ll = sline[i].lost_head;
 777                        while (ll) {
 778                                struct lline *tmp = ll;
 779                                ll = ll->next;
 780                                free(tmp);
 781                        }
 782                }
 783        }
 784        free(sline[0].p_lno);
 785        free(sline);
 786        return shown_header;
 787}
 788
 789#define COLONS "::::::::::::::::::::::::::::::::"
 790
 791static void show_raw_diff(struct combine_diff_path *p, int num_parent, const char *header, struct diff_options *opt)
 792{
 793        int i, offset, mod_type = 'A';
 794        const char *prefix;
 795        int line_termination, inter_name_termination;
 796
 797        line_termination = opt->line_termination;
 798        inter_name_termination = '\t';
 799        if (!line_termination)
 800                inter_name_termination = 0;
 801
 802        if (header)
 803                printf("%s%c", header, line_termination);
 804
 805        for (i = 0; i < num_parent; i++) {
 806                if (p->parent[i].mode)
 807                        mod_type = 'M';
 808        }
 809        if (!p->mode)
 810                mod_type = 'D';
 811
 812        if (opt->output_format == DIFF_FORMAT_RAW) {
 813                offset = strlen(COLONS) - num_parent;
 814                if (offset < 0)
 815                        offset = 0;
 816                prefix = COLONS + offset;
 817
 818                /* Show the modes */
 819                for (i = 0; i < num_parent; i++) {
 820                        printf("%s%06o", prefix, p->parent[i].mode);
 821                        prefix = " ";
 822                }
 823                printf("%s%06o", prefix, p->mode);
 824
 825                /* Show sha1's */
 826                for (i = 0; i < num_parent; i++)
 827                        printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
 828                                                         opt->abbrev));
 829                printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
 830        }
 831
 832        if (opt->output_format == DIFF_FORMAT_RAW ||
 833            opt->output_format == DIFF_FORMAT_NAME_STATUS) {
 834                for (i = 0; i < num_parent; i++)
 835                        putchar(p->parent[i].status);
 836                putchar(inter_name_termination);
 837        }
 838
 839        if (line_termination) {
 840                if (quote_c_style(p->path, NULL, NULL, 0))
 841                        quote_c_style(p->path, NULL, stdout, 0);
 842                else
 843                        printf("%s", p->path);
 844                putchar(line_termination);
 845        }
 846        else {
 847                printf("%s%c", p->path, line_termination);
 848        }
 849}
 850
 851int show_combined_diff(struct combine_diff_path *p,
 852                       int num_parent,
 853                       int dense,
 854                       const char *header,
 855                       struct diff_options *opt)
 856{
 857        if (!p->len)
 858                return 0;
 859        switch (opt->output_format) {
 860        case DIFF_FORMAT_RAW:
 861        case DIFF_FORMAT_NAME_STATUS:
 862        case DIFF_FORMAT_NAME:
 863                show_raw_diff(p, num_parent, header, opt);
 864                return 1;
 865
 866        default:
 867        case DIFF_FORMAT_PATCH:
 868                return show_patch_diff(p, num_parent, dense, header, opt);
 869        }
 870}
 871
 872const char *diff_tree_combined_merge(const unsigned char *sha1,
 873                             const char *header, int dense,
 874                             struct diff_options *opt)
 875{
 876        struct commit *commit = lookup_commit(sha1);
 877        struct diff_options diffopts;
 878        struct commit_list *parents;
 879        struct combine_diff_path *p, *paths = NULL;
 880        int num_parent, i, num_paths;
 881
 882        diffopts = *opt;
 883        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
 884        diffopts.recursive = 1;
 885
 886        /* count parents */
 887        for (parents = commit->parents, num_parent = 0;
 888             parents;
 889             parents = parents->next, num_parent++)
 890                ; /* nothing */
 891
 892        /* find set of paths that everybody touches */
 893        for (parents = commit->parents, i = 0;
 894             parents;
 895             parents = parents->next, i++) {
 896                struct commit *parent = parents->item;
 897                diff_tree_sha1(parent->object.sha1, commit->object.sha1, "",
 898                               &diffopts);
 899                diffcore_std(&diffopts);
 900                paths = intersect_paths(paths, i, num_parent);
 901                diff_flush(&diffopts);
 902        }
 903
 904        /* find out surviving paths */
 905        for (num_paths = 0, p = paths; p; p = p->next) {
 906                if (p->len)
 907                        num_paths++;
 908        }
 909        if (num_paths) {
 910                for (p = paths; p; p = p->next) {
 911                        if (show_combined_diff(p, num_parent, dense,
 912                                               header, opt))
 913                                header = NULL;
 914                }
 915        }
 916
 917        /* Clean things up */
 918        while (paths) {
 919                struct combine_diff_path *tmp = paths;
 920                paths = paths->next;
 921                free(tmp);
 922        }
 923        return header;
 924}