e17afd109633da16e8aad0cced23556fa41171be
   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
   9static int uninteresting(struct diff_filepair *p)
  10{
  11        if (diff_unmodified_pair(p))
  12                return 1;
  13        return 0;
  14}
  15
  16static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
  17{
  18        struct diff_queue_struct *q = &diff_queued_diff;
  19        struct combine_diff_path *p;
  20        int i;
  21
  22        if (!n) {
  23                struct combine_diff_path *list = NULL, **tail = &list;
  24                for (i = 0; i < q->nr; i++) {
  25                        int len;
  26                        const char *path;
  27                        if (uninteresting(q->queue[i]))
  28                                continue;
  29                        path = q->queue[i]->two->path;
  30                        len = strlen(path);
  31                        p = xmalloc(combine_diff_path_size(num_parent, len));
  32                        p->path = (char*) &(p->parent[num_parent]);
  33                        memcpy(p->path, path, len);
  34                        p->path[len] = 0;
  35                        p->len = len;
  36                        p->next = NULL;
  37                        memset(p->parent, 0,
  38                               sizeof(p->parent[0]) * num_parent);
  39
  40                        memcpy(p->sha1, q->queue[i]->two->sha1, 20);
  41                        p->mode = q->queue[i]->two->mode;
  42                        memcpy(p->parent[n].sha1, q->queue[i]->one->sha1, 20);
  43                        p->parent[n].mode = q->queue[i]->one->mode;
  44                        p->parent[n].status = q->queue[i]->status;
  45                        *tail = p;
  46                        tail = &p->next;
  47                }
  48                return list;
  49        }
  50
  51        for (p = curr; p; p = p->next) {
  52                int found = 0;
  53                if (!p->len)
  54                        continue;
  55                for (i = 0; i < q->nr; i++) {
  56                        const char *path;
  57                        int len;
  58
  59                        if (uninteresting(q->queue[i]))
  60                                continue;
  61                        path = q->queue[i]->two->path;
  62                        len = strlen(path);
  63                        if (len == p->len && !memcmp(path, p->path, len)) {
  64                                found = 1;
  65                                memcpy(p->parent[n].sha1,
  66                                       q->queue[i]->one->sha1, 20);
  67                                p->parent[n].mode = q->queue[i]->one->mode;
  68                                p->parent[n].status = q->queue[i]->status;
  69                                break;
  70                        }
  71                }
  72                if (!found)
  73                        p->len = 0;
  74        }
  75        return curr;
  76}
  77
  78/* Lines lost from parent */
  79struct lline {
  80        struct lline *next;
  81        int len;
  82        unsigned long parent_map;
  83        char line[FLEX_ARRAY];
  84};
  85
  86/* Lines surviving in the merge result */
  87struct sline {
  88        struct lline *lost_head, **lost_tail;
  89        char *bol;
  90        int len;
  91        /* bit 0 up to (N-1) are on if the parent has this line (i.e.
  92         * we did not change it).
  93         * bit N is used for "interesting" lines, including context.
  94         */
  95        unsigned long flag;
  96        unsigned long *p_lno;
  97};
  98
  99static char *grab_blob(const unsigned char *sha1, unsigned long *size)
 100{
 101        char *blob;
 102        char type[20];
 103        if (!memcmp(sha1, null_sha1, 20)) {
 104                /* deleted blob */
 105                *size = 0;
 106                return xcalloc(1, 1);
 107        }
 108        blob = read_sha1_file(sha1, type, size);
 109        if (strcmp(type, blob_type))
 110                die("object '%s' is not a blob!", sha1_to_hex(sha1));
 111        return blob;
 112}
 113
 114static int parse_num(char **cp_p, unsigned int *num_p)
 115{
 116        char *cp = *cp_p;
 117        unsigned int num = 0;
 118        int read_some;
 119
 120        while ('0' <= *cp && *cp <= '9')
 121                num = num * 10 + *cp++ - '0';
 122        if (!(read_some = cp - *cp_p))
 123                return -1;
 124        *cp_p = cp;
 125        *num_p = num;
 126        return 0;
 127}
 128
 129static int parse_hunk_header(char *line, int len,
 130                             unsigned int *ob, unsigned int *on,
 131                             unsigned int *nb, unsigned int *nn)
 132{
 133        char *cp;
 134        cp = line + 4;
 135        if (parse_num(&cp, ob)) {
 136        bad_line:
 137                return error("malformed diff output: %s", line);
 138        }
 139        if (*cp == ',') {
 140                cp++;
 141                if (parse_num(&cp, on))
 142                        goto bad_line;
 143        }
 144        else
 145                *on = 1;
 146        if (*cp++ != ' ' || *cp++ != '+')
 147                goto bad_line;
 148        if (parse_num(&cp, nb))
 149                goto bad_line;
 150        if (*cp == ',') {
 151                cp++;
 152                if (parse_num(&cp, nn))
 153                        goto bad_line;
 154        }
 155        else
 156                *nn = 1;
 157        return -!!memcmp(cp, " @@", 3);
 158}
 159
 160static void append_lost(struct sline *sline, int n, const char *line, int len)
 161{
 162        struct lline *lline;
 163        unsigned long this_mask = (1UL<<n);
 164        if (line[len-1] == '\n')
 165                len--;
 166
 167        /* Check to see if we can squash things */
 168        if (sline->lost_head) {
 169                struct lline *last_one = NULL;
 170                /* We cannot squash it with earlier one */
 171                for (lline = sline->lost_head;
 172                     lline;
 173                     lline = lline->next)
 174                        if (lline->parent_map & this_mask)
 175                                last_one = lline;
 176                lline = last_one ? last_one->next : sline->lost_head;
 177                while (lline) {
 178                        if (lline->len == len &&
 179                            !memcmp(lline->line, line, len)) {
 180                                lline->parent_map |= this_mask;
 181                                return;
 182                        }
 183                        lline = lline->next;
 184                }
 185        }
 186
 187        lline = xmalloc(sizeof(*lline) + len + 1);
 188        lline->len = len;
 189        lline->next = NULL;
 190        lline->parent_map = this_mask;
 191        memcpy(lline->line, line, len);
 192        lline->line[len] = 0;
 193        *sline->lost_tail = lline;
 194        sline->lost_tail = &lline->next;
 195}
 196
 197struct combine_diff_state {
 198        struct xdiff_emit_state xm;
 199
 200        unsigned int lno, ob, on, nb, nn;
 201        unsigned long nmask;
 202        int num_parent;
 203        int n;
 204        struct sline *sline;
 205        struct sline *lost_bucket;
 206};
 207
 208static void consume_line(void *state_, char *line, unsigned long len)
 209{
 210        struct combine_diff_state *state = state_;
 211        if (5 < len && !memcmp("@@ -", line, 4)) {
 212                if (parse_hunk_header(line, len,
 213                                      &state->ob, &state->on,
 214                                      &state->nb, &state->nn))
 215                        return;
 216                state->lno = state->nb;
 217                if (!state->nb)
 218                        /* @@ -1,2 +0,0 @@ to remove the
 219                         * first two lines...
 220                         */
 221                        state->nb = 1;
 222                if (state->nn == 0)
 223                        /* @@ -X,Y +N,0 @@ removed Y lines
 224                         * that would have come *after* line N
 225                         * in the result.  Our lost buckets hang
 226                         * to the line after the removed lines,
 227                         */
 228                        state->lost_bucket = &state->sline[state->nb];
 229                else
 230                        state->lost_bucket = &state->sline[state->nb-1];
 231                if (!state->sline[state->nb-1].p_lno)
 232                        state->sline[state->nb-1].p_lno =
 233                                xcalloc(state->num_parent,
 234                                        sizeof(unsigned long));
 235                state->sline[state->nb-1].p_lno[state->n] = state->ob;
 236                return;
 237        }
 238        if (!state->lost_bucket)
 239                return; /* not in any hunk yet */
 240        switch (line[0]) {
 241        case '-':
 242                append_lost(state->lost_bucket, state->n, line+1, len-1);
 243                break;
 244        case '+':
 245                state->sline[state->lno-1].flag |= state->nmask;
 246                state->lno++;
 247                break;
 248        }
 249}
 250
 251static void combine_diff(const unsigned char *parent, mmfile_t *result_file,
 252                         struct sline *sline, int cnt, int n, int num_parent)
 253{
 254        unsigned int p_lno, lno;
 255        unsigned long nmask = (1UL << n);
 256        xpparam_t xpp;
 257        xdemitconf_t xecfg;
 258        mmfile_t parent_file;
 259        xdemitcb_t ecb;
 260        struct combine_diff_state state;
 261        unsigned long sz;
 262
 263        if (!cnt)
 264                return; /* result deleted */
 265
 266        parent_file.ptr = grab_blob(parent, &sz);
 267        parent_file.size = sz;
 268        xpp.flags = XDF_NEED_MINIMAL;
 269        xecfg.ctxlen = 0;
 270        xecfg.flags = 0;
 271        ecb.outf = xdiff_outf;
 272        ecb.priv = &state;
 273        memset(&state, 0, sizeof(state));
 274        state.xm.consume = consume_line;
 275        state.nmask = nmask;
 276        state.sline = sline;
 277        state.lno = 1;
 278        state.num_parent = num_parent;
 279        state.n = n;
 280
 281        xdl_diff(&parent_file, result_file, &xpp, &xecfg, &ecb);
 282        free(parent_file.ptr);
 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 result_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        int working_tree_file = !memcmp(elem->sha1, null_sha1, 20);
 634        int abbrev = opt->full_index ? 40 : DEFAULT_ABBREV;
 635        mmfile_t result_file;
 636
 637        /* Read the result of merge first */
 638        if (!working_tree_file)
 639                result = grab_blob(elem->sha1, &result_size);
 640        else {
 641                /* Used by diff-tree to read from the working tree */
 642                struct stat st;
 643                int fd;
 644                if (0 <= (fd = open(elem->path, O_RDONLY)) &&
 645                    !fstat(fd, &st)) {
 646                        int len = st.st_size;
 647                        int cnt = 0;
 648
 649                        elem->mode = canon_mode(st.st_mode);
 650                        result_size = len;
 651                        result = xmalloc(len + 1);
 652                        while (cnt < len) {
 653                                int done = xread(fd, result+cnt, len-cnt);
 654                                if (done == 0)
 655                                        break;
 656                                if (done < 0)
 657                                        die("read error '%s'", elem->path);
 658                                cnt += done;
 659                        }
 660                        result[len] = 0;
 661                }
 662                else {
 663                        /* deleted file */
 664                        result_size = 0;
 665                        elem->mode = 0;
 666                        result = xmalloc(1);
 667                        result[0] = 0;
 668                }
 669                if (0 <= fd)
 670                        close(fd);
 671        }
 672
 673        for (cnt = 0, cp = result; cp - result < result_size; cp++) {
 674                if (*cp == '\n')
 675                        cnt++;
 676        }
 677        if (result_size && result[result_size-1] != '\n')
 678                cnt++; /* incomplete line */
 679
 680        sline = xcalloc(cnt+1, sizeof(*sline));
 681        ep = result;
 682        sline[0].bol = result;
 683        for (lno = 0; lno <= cnt; lno++) {
 684                sline[lno].lost_tail = &sline[lno].lost_head;
 685                sline[lno].flag = 0;
 686        }
 687        for (lno = 0, cp = result; cp - result < result_size; cp++) {
 688                if (*cp == '\n') {
 689                        sline[lno].len = cp - sline[lno].bol;
 690                        lno++;
 691                        if (lno < cnt)
 692                                sline[lno].bol = cp + 1;
 693                }
 694        }
 695        if (result_size && result[result_size-1] != '\n')
 696                sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
 697
 698        result_file.ptr = result;
 699        result_file.size = result_size;
 700
 701        sline[0].p_lno = xcalloc((cnt+1) * num_parent, sizeof(unsigned long));
 702        for (lno = 0; lno < cnt; lno++)
 703                sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
 704
 705        for (i = 0; i < num_parent; i++) {
 706                int j;
 707                for (j = 0; j < i; j++) {
 708                        if (!memcmp(elem->parent[i].sha1,
 709                                    elem->parent[j].sha1, 20)) {
 710                                reuse_combine_diff(sline, cnt, i, j);
 711                                break;
 712                        }
 713                }
 714                if (i <= j)
 715                        combine_diff(elem->parent[i].sha1, &result_file, sline,
 716                                     cnt, i, num_parent);
 717                if (elem->parent[i].mode != elem->mode)
 718                        mode_differs = 1;
 719        }
 720
 721        show_hunks = make_hunks(sline, cnt, num_parent, dense);
 722
 723        if (show_hunks || mode_differs || working_tree_file) {
 724                const char *abb;
 725
 726                if (header) {
 727                        shown_header++;
 728                        printf("%s%c", header, opt->line_termination);
 729                }
 730                printf("diff --%s ", dense ? "cc" : "combined");
 731                if (quote_c_style(elem->path, NULL, NULL, 0))
 732                        quote_c_style(elem->path, NULL, stdout, 0);
 733                else
 734                        printf("%s", elem->path);
 735                putchar('\n');
 736                printf("index ");
 737                for (i = 0; i < num_parent; i++) {
 738                        abb = find_unique_abbrev(elem->parent[i].sha1,
 739                                                 abbrev);
 740                        printf("%s%s", i ? "," : "", abb);
 741                }
 742                abb = find_unique_abbrev(elem->sha1, abbrev);
 743                printf("..%s\n", abb);
 744
 745                if (mode_differs) {
 746                        int added = !!elem->mode;
 747                        for (i = 0; added && i < num_parent; i++)
 748                                if (elem->parent[i].status !=
 749                                    DIFF_STATUS_ADDED)
 750                                        added = 0;
 751                        if (added)
 752                                printf("new file mode %06o", elem->mode);
 753                        else {
 754                                if (!elem->mode)
 755                                        printf("deleted file ");
 756                                printf("mode ");
 757                                for (i = 0; i < num_parent; i++) {
 758                                        printf("%s%06o", i ? "," : "",
 759                                               elem->parent[i].mode);
 760                                }
 761                                if (elem->mode)
 762                                        printf("..%06o", elem->mode);
 763                        }
 764                        putchar('\n');
 765                }
 766                dump_sline(sline, cnt, num_parent);
 767        }
 768        free(result);
 769
 770        for (i = 0; i < cnt; i++) {
 771                if (sline[i].lost_head) {
 772                        struct lline *ll = sline[i].lost_head;
 773                        while (ll) {
 774                                struct lline *tmp = ll;
 775                                ll = ll->next;
 776                                free(tmp);
 777                        }
 778                }
 779        }
 780        free(sline[0].p_lno);
 781        free(sline);
 782        return shown_header;
 783}
 784
 785#define COLONS "::::::::::::::::::::::::::::::::"
 786
 787static void show_raw_diff(struct combine_diff_path *p, int num_parent, const char *header, struct diff_options *opt)
 788{
 789        int i, offset, mod_type = 'A';
 790        const char *prefix;
 791        int line_termination, inter_name_termination;
 792
 793        line_termination = opt->line_termination;
 794        inter_name_termination = '\t';
 795        if (!line_termination)
 796                inter_name_termination = 0;
 797
 798        if (header)
 799                printf("%s%c", header, line_termination);
 800
 801        for (i = 0; i < num_parent; i++) {
 802                if (p->parent[i].mode)
 803                        mod_type = 'M';
 804        }
 805        if (!p->mode)
 806                mod_type = 'D';
 807
 808        if (opt->output_format == DIFF_FORMAT_RAW) {
 809                offset = strlen(COLONS) - num_parent;
 810                if (offset < 0)
 811                        offset = 0;
 812                prefix = COLONS + offset;
 813
 814                /* Show the modes */
 815                for (i = 0; i < num_parent; i++) {
 816                        printf("%s%06o", prefix, p->parent[i].mode);
 817                        prefix = " ";
 818                }
 819                printf("%s%06o", prefix, p->mode);
 820
 821                /* Show sha1's */
 822                for (i = 0; i < num_parent; i++)
 823                        printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
 824                                                         opt->abbrev));
 825                printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
 826        }
 827
 828        if (opt->output_format == DIFF_FORMAT_RAW ||
 829            opt->output_format == DIFF_FORMAT_NAME_STATUS) {
 830                for (i = 0; i < num_parent; i++)
 831                        putchar(p->parent[i].status);
 832                putchar(inter_name_termination);
 833        }
 834
 835        if (line_termination) {
 836                if (quote_c_style(p->path, NULL, NULL, 0))
 837                        quote_c_style(p->path, NULL, stdout, 0);
 838                else
 839                        printf("%s", p->path);
 840                putchar(line_termination);
 841        }
 842        else {
 843                printf("%s%c", p->path, line_termination);
 844        }
 845}
 846
 847int show_combined_diff(struct combine_diff_path *p,
 848                       int num_parent,
 849                       int dense,
 850                       const char *header,
 851                       struct diff_options *opt)
 852{
 853        if (!p->len)
 854                return 0;
 855        switch (opt->output_format) {
 856        case DIFF_FORMAT_RAW:
 857        case DIFF_FORMAT_NAME_STATUS:
 858        case DIFF_FORMAT_NAME:
 859                show_raw_diff(p, num_parent, header, opt);
 860                return 1;
 861
 862        default:
 863        case DIFF_FORMAT_PATCH:
 864                return show_patch_diff(p, num_parent, dense, header, opt);
 865        }
 866}
 867
 868const char *diff_tree_combined_merge(const unsigned char *sha1,
 869                             const char *header, int dense,
 870                             struct diff_options *opt)
 871{
 872        struct commit *commit = lookup_commit(sha1);
 873        struct diff_options diffopts;
 874        struct commit_list *parents;
 875        struct combine_diff_path *p, *paths = NULL;
 876        int num_parent, i, num_paths;
 877
 878        diffopts = *opt;
 879        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
 880        diffopts.recursive = 1;
 881
 882        /* count parents */
 883        for (parents = commit->parents, num_parent = 0;
 884             parents;
 885             parents = parents->next, num_parent++)
 886                ; /* nothing */
 887
 888        /* find set of paths that everybody touches */
 889        for (parents = commit->parents, i = 0;
 890             parents;
 891             parents = parents->next, i++) {
 892                struct commit *parent = parents->item;
 893                diff_tree_sha1(parent->object.sha1, commit->object.sha1, "",
 894                               &diffopts);
 895                diffcore_std(&diffopts);
 896                paths = intersect_paths(paths, i, num_parent);
 897                diff_flush(&diffopts);
 898        }
 899
 900        /* find out surviving paths */
 901        for (num_paths = 0, p = paths; p; p = p->next) {
 902                if (p->len)
 903                        num_paths++;
 904        }
 905        if (num_paths) {
 906                for (p = paths; p; p = p->next) {
 907                        if (show_combined_diff(p, num_parent, dense,
 908                                               header, opt))
 909                                header = NULL;
 910                }
 911        }
 912
 913        /* Clean things up */
 914        while (paths) {
 915                struct combine_diff_path *tmp = paths;
 916                paths = paths->next;
 917                free(tmp);
 918        }
 919        return header;
 920}