combine-diff.con commit Merge git://git.kernel.org/pub/scm/gitk/gitk (67e31d6)
   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
  10static int uninteresting(struct diff_filepair *p)
  11{
  12        if (diff_unmodified_pair(p))
  13                return 1;
  14        return 0;
  15}
  16
  17static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
  18{
  19        struct diff_queue_struct *q = &diff_queued_diff;
  20        struct combine_diff_path *p;
  21        int i;
  22
  23        if (!n) {
  24                struct combine_diff_path *list = NULL, **tail = &list;
  25                for (i = 0; i < q->nr; i++) {
  26                        int len;
  27                        const char *path;
  28                        if (uninteresting(q->queue[i]))
  29                                continue;
  30                        path = q->queue[i]->two->path;
  31                        len = strlen(path);
  32                        p = xmalloc(combine_diff_path_size(num_parent, len));
  33                        p->path = (char*) &(p->parent[num_parent]);
  34                        memcpy(p->path, path, len);
  35                        p->path[len] = 0;
  36                        p->len = len;
  37                        p->next = NULL;
  38                        memset(p->parent, 0,
  39                               sizeof(p->parent[0]) * num_parent);
  40
  41                        memcpy(p->sha1, q->queue[i]->two->sha1, 20);
  42                        p->mode = q->queue[i]->two->mode;
  43                        memcpy(p->parent[n].sha1, q->queue[i]->one->sha1, 20);
  44                        p->parent[n].mode = q->queue[i]->one->mode;
  45                        p->parent[n].status = q->queue[i]->status;
  46                        *tail = p;
  47                        tail = &p->next;
  48                }
  49                return list;
  50        }
  51
  52        for (p = curr; p; p = p->next) {
  53                int found = 0;
  54                if (!p->len)
  55                        continue;
  56                for (i = 0; i < q->nr; i++) {
  57                        const char *path;
  58                        int len;
  59
  60                        if (uninteresting(q->queue[i]))
  61                                continue;
  62                        path = q->queue[i]->two->path;
  63                        len = strlen(path);
  64                        if (len == p->len && !memcmp(path, p->path, len)) {
  65                                found = 1;
  66                                memcpy(p->parent[n].sha1,
  67                                       q->queue[i]->one->sha1, 20);
  68                                p->parent[n].mode = q->queue[i]->one->mode;
  69                                p->parent[n].status = q->queue[i]->status;
  70                                break;
  71                        }
  72                }
  73                if (!found)
  74                        p->len = 0;
  75        }
  76        return curr;
  77}
  78
  79/* Lines lost from parent */
  80struct lline {
  81        struct lline *next;
  82        int len;
  83        unsigned long parent_map;
  84        char line[FLEX_ARRAY];
  85};
  86
  87/* Lines surviving in the merge result */
  88struct sline {
  89        struct lline *lost_head, **lost_tail;
  90        char *bol;
  91        int len;
  92        /* bit 0 up to (N-1) are on if the parent has this line (i.e.
  93         * we did not change it).
  94         * bit N is used for "interesting" lines, including context.
  95         */
  96        unsigned long flag;
  97        unsigned long *p_lno;
  98};
  99
 100static char *grab_blob(const unsigned char *sha1, unsigned long *size)
 101{
 102        char *blob;
 103        char type[20];
 104        if (!memcmp(sha1, null_sha1, 20)) {
 105                /* deleted blob */
 106                *size = 0;
 107                return xcalloc(1, 1);
 108        }
 109        blob = read_sha1_file(sha1, type, size);
 110        if (strcmp(type, blob_type))
 111                die("object '%s' is not a blob!", sha1_to_hex(sha1));
 112        return blob;
 113}
 114
 115static 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
 152struct 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
 164static 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
 207static void combine_diff(const unsigned char *parent, mmfile_t *result_file,
 208                         struct sline *sline, unsigned int cnt, int n,
 209                         int num_parent)
 210{
 211        unsigned int p_lno, lno;
 212        unsigned long nmask = (1UL << n);
 213        xpparam_t xpp;
 214        xdemitconf_t xecfg;
 215        mmfile_t parent_file;
 216        xdemitcb_t ecb;
 217        struct combine_diff_state state;
 218        unsigned long sz;
 219
 220        if (!cnt)
 221                return; /* result deleted */
 222
 223        parent_file.ptr = grab_blob(parent, &sz);
 224        parent_file.size = sz;
 225        xpp.flags = XDF_NEED_MINIMAL;
 226        xecfg.ctxlen = 0;
 227        xecfg.flags = 0;
 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        xdl_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
 265static unsigned long context = 3;
 266static char combine_marker = '@';
 267
 268static 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
 276static 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
 293static 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
 316static 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 i;
 321
 322        /* Two groups of interesting lines may have a short gap of
 323         * uninteresting lines.  Connect such groups to give them a
 324         * bit of context.
 325         *
 326         * We first start from what the interesting() function says,
 327         * and mark them with "mark", and paint context lines with the
 328         * mark.  So interesting() would still say false for such context
 329         * lines but they are treated as "interesting" in the end.
 330         */
 331        i = find_next(sline, mark, 0, cnt, 0);
 332        if (cnt < i)
 333                return 0;
 334
 335        while (i <= cnt) {
 336                unsigned long j = (context < i) ? (i - context) : 0;
 337                unsigned long k;
 338
 339                /* Paint a few lines before the first interesting line. */
 340                while (j < i)
 341                        sline[j++].flag |= mark;
 342
 343        again:
 344                /* we know up to i is to be included.  where does the
 345                 * next uninteresting one start?
 346                 */
 347                j = find_next(sline, mark, i, cnt, 1);
 348                if (cnt < j)
 349                        break; /* the rest are all interesting */
 350
 351                /* lookahead context lines */
 352                k = find_next(sline, mark, j, cnt, 0);
 353                j = adjust_hunk_tail(sline, all_mask, i, j);
 354
 355                if (k < j + context) {
 356                        /* k is interesting and [j,k) are not, but
 357                         * paint them interesting because the gap is small.
 358                         */
 359                        while (j < k)
 360                                sline[j++].flag |= mark;
 361                        i = k;
 362                        goto again;
 363                }
 364
 365                /* j is the first uninteresting line and there is
 366                 * no overlap beyond it within context lines.  Paint
 367                 * the trailing edge a bit.
 368                 */
 369                i = k;
 370                k = (j + context < cnt+1) ? j + context : cnt+1;
 371                while (j < k)
 372                        sline[j++].flag |= mark;
 373        }
 374        return 1;
 375}
 376
 377static int make_hunks(struct sline *sline, unsigned long cnt,
 378                       int num_parent, int dense)
 379{
 380        unsigned long all_mask = (1UL<<num_parent) - 1;
 381        unsigned long mark = (1UL<<num_parent);
 382        unsigned long i;
 383        int has_interesting = 0;
 384
 385        for (i = 0; i <= cnt; i++) {
 386                if (interesting(&sline[i], all_mask))
 387                        sline[i].flag |= mark;
 388                else
 389                        sline[i].flag &= ~mark;
 390        }
 391        if (!dense)
 392                return give_context(sline, cnt, num_parent);
 393
 394        /* Look at each hunk, and if we have changes from only one
 395         * parent, or the changes are the same from all but one
 396         * parent, mark that uninteresting.
 397         */
 398        i = 0;
 399        while (i <= cnt) {
 400                unsigned long j, hunk_begin, hunk_end;
 401                unsigned long same_diff;
 402                while (i <= cnt && !(sline[i].flag & mark))
 403                        i++;
 404                if (cnt < i)
 405                        break; /* No more interesting hunks */
 406                hunk_begin = i;
 407                for (j = i + 1; j <= cnt; j++) {
 408                        if (!(sline[j].flag & mark)) {
 409                                /* Look beyond the end to see if there
 410                                 * is an interesting line after this
 411                                 * hunk within context span.
 412                                 */
 413                                unsigned long la; /* lookahead */
 414                                int contin = 0;
 415                                la = adjust_hunk_tail(sline, all_mask,
 416                                                     hunk_begin, j);
 417                                la = (la + context < cnt + 1) ?
 418                                        (la + context) : cnt + 1;
 419                                while (j <= --la) {
 420                                        if (sline[la].flag & mark) {
 421                                                contin = 1;
 422                                                break;
 423                                        }
 424                                }
 425                                if (!contin)
 426                                        break;
 427                                j = la;
 428                        }
 429                }
 430                hunk_end = j;
 431
 432                /* [i..hunk_end) are interesting.  Now is it really
 433                 * interesting?  We check if there are only two versions
 434                 * and the result matches one of them.  That is, we look
 435                 * at:
 436                 *   (+) line, which records lines added to which parents;
 437                 *       this line appears in the result.
 438                 *   (-) line, which records from what parents the line
 439                 *       was removed; this line does not appear in the result.
 440                 * then check the set of parents the result has difference
 441                 * from, from all lines.  If there are lines that has
 442                 * different set of parents that the result has differences
 443                 * from, that means we have more than two versions.
 444                 *
 445                 * Even when we have only two versions, if the result does
 446                 * not match any of the parents, the it should be considered
 447                 * interesting.  In such a case, we would have all '+' line.
 448                 * After passing the above "two versions" test, that would
 449                 * appear as "the same set of parents" to be "all parents".
 450                 */
 451                same_diff = 0;
 452                has_interesting = 0;
 453                for (j = i; j < hunk_end && !has_interesting; j++) {
 454                        unsigned long this_diff = sline[j].flag & all_mask;
 455                        struct lline *ll = sline[j].lost_head;
 456                        if (this_diff) {
 457                                /* This has some changes.  Is it the
 458                                 * same as others?
 459                                 */
 460                                if (!same_diff)
 461                                        same_diff = this_diff;
 462                                else if (same_diff != this_diff) {
 463                                        has_interesting = 1;
 464                                        break;
 465                                }
 466                        }
 467                        while (ll && !has_interesting) {
 468                                /* Lost this line from these parents;
 469                                 * who are they?  Are they the same?
 470                                 */
 471                                this_diff = ll->parent_map;
 472                                if (!same_diff)
 473                                        same_diff = this_diff;
 474                                else if (same_diff != this_diff) {
 475                                        has_interesting = 1;
 476                                }
 477                                ll = ll->next;
 478                        }
 479                }
 480
 481                if (!has_interesting && same_diff != all_mask) {
 482                        /* This hunk is not that interesting after all */
 483                        for (j = hunk_begin; j < hunk_end; j++)
 484                                sline[j].flag &= ~mark;
 485                }
 486                i = hunk_end;
 487        }
 488
 489        has_interesting = give_context(sline, cnt, num_parent);
 490        return has_interesting;
 491}
 492
 493static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n)
 494{
 495        l0 = sline[l0].p_lno[n];
 496        l1 = sline[l1].p_lno[n];
 497        printf(" -%lu,%lu", l0, l1-l0);
 498}
 499
 500static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 501                       int use_color)
 502{
 503        unsigned long mark = (1UL<<num_parent);
 504        int i;
 505        unsigned long lno = 0;
 506        const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
 507        const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
 508        const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
 509        const char *c_plain = diff_get_color(use_color, DIFF_PLAIN);
 510        const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 511
 512        if (!cnt)
 513                return; /* result deleted */
 514
 515        while (1) {
 516                struct sline *sl = &sline[lno];
 517                unsigned long hunk_end;
 518                unsigned long rlines;
 519                while (lno <= cnt && !(sline[lno].flag & mark))
 520                        lno++;
 521                if (cnt < lno)
 522                        break;
 523                else {
 524                        for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
 525                                if (!(sline[hunk_end].flag & mark))
 526                                        break;
 527                }
 528                rlines = hunk_end - lno;
 529                if (cnt < hunk_end)
 530                        rlines--; /* pointing at the last delete hunk */
 531                fputs(c_frag, stdout);
 532                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 533                for (i = 0; i < num_parent; i++)
 534                        show_parent_lno(sline, lno, hunk_end, i);
 535                printf(" +%lu,%lu ", lno+1, rlines);
 536                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 537                printf("%s\n", c_reset);
 538                while (lno < hunk_end) {
 539                        struct lline *ll;
 540                        int j;
 541                        unsigned long p_mask;
 542                        sl = &sline[lno++];
 543                        ll = sl->lost_head;
 544                        while (ll) {
 545                                fputs(c_old, stdout);
 546                                for (j = 0; j < num_parent; j++) {
 547                                        if (ll->parent_map & (1UL<<j))
 548                                                putchar('-');
 549                                        else
 550                                                putchar(' ');
 551                                }
 552                                printf("%s%s\n", ll->line, c_reset);
 553                                ll = ll->next;
 554                        }
 555                        if (cnt < lno)
 556                                break;
 557                        p_mask = 1;
 558                        if (!(sl->flag & (mark-1)))
 559                                fputs(c_plain, stdout);
 560                        else
 561                                fputs(c_new, stdout);
 562                        for (j = 0; j < num_parent; j++) {
 563                                if (p_mask & sl->flag)
 564                                        putchar('+');
 565                                else
 566                                        putchar(' ');
 567                                p_mask <<= 1;
 568                        }
 569                        printf("%.*s%s\n", sl->len, sl->bol, c_reset);
 570                }
 571        }
 572}
 573
 574static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 575                               int i, int j)
 576{
 577        /* We have already examined parent j and we know parent i
 578         * and parent j are the same, so reuse the combined result
 579         * of parent j for parent i.
 580         */
 581        unsigned long lno, imask, jmask;
 582        imask = (1UL<<i);
 583        jmask = (1UL<<j);
 584
 585        for (lno = 0; lno <= cnt; lno++) {
 586                struct lline *ll = sline->lost_head;
 587                sline->p_lno[i] = sline->p_lno[j];
 588                while (ll) {
 589                        if (ll->parent_map & jmask)
 590                                ll->parent_map |= imask;
 591                        ll = ll->next;
 592                }
 593                if (sline->flag & jmask)
 594                        sline->flag |= imask;
 595                sline++;
 596        }
 597        /* the overall size of the file (sline[cnt]) */
 598        sline->p_lno[i] = sline->p_lno[j];
 599}
 600
 601static void dump_quoted_path(const char *prefix, const char *path,
 602                             const char *c_meta, const char *c_reset)
 603{
 604        printf("%s%s", c_meta, prefix);
 605        if (quote_c_style(path, NULL, NULL, 0))
 606                quote_c_style(path, NULL, stdout, 0);
 607        else
 608                printf("%s", path);
 609        printf("%s\n", c_reset);
 610}
 611
 612static int show_patch_diff(struct combine_diff_path *elem, int num_parent,
 613                           int dense, struct rev_info *rev)
 614{
 615        struct diff_options *opt = &rev->diffopt;
 616        unsigned long result_size, cnt, lno;
 617        char *result, *cp;
 618        struct sline *sline; /* survived lines */
 619        int mode_differs = 0;
 620        int i, show_hunks, shown_header = 0;
 621        int working_tree_file = !memcmp(elem->sha1, null_sha1, 20);
 622        int abbrev = opt->full_index ? 40 : DEFAULT_ABBREV;
 623        mmfile_t result_file;
 624
 625        context = opt->context;
 626        /* Read the result of merge first */
 627        if (!working_tree_file)
 628                result = grab_blob(elem->sha1, &result_size);
 629        else {
 630                /* Used by diff-tree to read from the working tree */
 631                struct stat st;
 632                int fd;
 633                if (0 <= (fd = open(elem->path, O_RDONLY)) &&
 634                    !fstat(fd, &st)) {
 635                        int len = st.st_size;
 636                        int sz = 0;
 637
 638                        elem->mode = canon_mode(st.st_mode);
 639                        result_size = len;
 640                        result = xmalloc(len + 1);
 641                        while (sz < len) {
 642                                int done = xread(fd, result+sz, len-sz);
 643                                if (done == 0)
 644                                        break;
 645                                if (done < 0)
 646                                        die("read error '%s'", elem->path);
 647                                sz += done;
 648                        }
 649                        result[len] = 0;
 650                }
 651                else {
 652                        /* deleted file */
 653                        result_size = 0;
 654                        elem->mode = 0;
 655                        result = xcalloc(1, 1);
 656                }
 657                if (0 <= fd)
 658                        close(fd);
 659        }
 660
 661        for (cnt = 0, cp = result; cp < result + result_size; cp++) {
 662                if (*cp == '\n')
 663                        cnt++;
 664        }
 665        if (result_size && result[result_size-1] != '\n')
 666                cnt++; /* incomplete line */
 667
 668        sline = xcalloc(cnt+2, sizeof(*sline));
 669        sline[0].bol = result;
 670        for (lno = 0; lno <= cnt + 1; lno++) {
 671                sline[lno].lost_tail = &sline[lno].lost_head;
 672                sline[lno].flag = 0;
 673        }
 674        for (lno = 0, cp = result; cp < result + result_size; cp++) {
 675                if (*cp == '\n') {
 676                        sline[lno].len = cp - sline[lno].bol;
 677                        lno++;
 678                        if (lno < cnt)
 679                                sline[lno].bol = cp + 1;
 680                }
 681        }
 682        if (result_size && result[result_size-1] != '\n')
 683                sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
 684
 685        result_file.ptr = result;
 686        result_file.size = result_size;
 687
 688        /* Even p_lno[cnt+1] is valid -- that is for the end line number
 689         * for deletion hunk at the end.
 690         */
 691        sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
 692        for (lno = 0; lno <= cnt; lno++)
 693                sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
 694
 695        for (i = 0; i < num_parent; i++) {
 696                int j;
 697                for (j = 0; j < i; j++) {
 698                        if (!memcmp(elem->parent[i].sha1,
 699                                    elem->parent[j].sha1, 20)) {
 700                                reuse_combine_diff(sline, cnt, i, j);
 701                                break;
 702                        }
 703                }
 704                if (i <= j)
 705                        combine_diff(elem->parent[i].sha1, &result_file, sline,
 706                                     cnt, i, num_parent);
 707                if (elem->parent[i].mode != elem->mode)
 708                        mode_differs = 1;
 709        }
 710
 711        show_hunks = make_hunks(sline, cnt, num_parent, dense);
 712
 713        if (show_hunks || mode_differs || working_tree_file) {
 714                const char *abb;
 715                int use_color = opt->color_diff;
 716                const char *c_meta = diff_get_color(use_color, DIFF_METAINFO);
 717                const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 718
 719                if (rev->loginfo)
 720                        show_log(rev, opt->msg_sep);
 721                dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
 722                                 elem->path, c_meta, c_reset);
 723                printf("%sindex ", c_meta);
 724                for (i = 0; i < num_parent; i++) {
 725                        abb = find_unique_abbrev(elem->parent[i].sha1,
 726                                                 abbrev);
 727                        printf("%s%s", i ? "," : "", abb);
 728                }
 729                abb = find_unique_abbrev(elem->sha1, abbrev);
 730                printf("..%s%s\n", abb, c_reset);
 731
 732                if (mode_differs) {
 733                        int added = !!elem->mode;
 734                        for (i = 0; added && i < num_parent; i++)
 735                                if (elem->parent[i].status !=
 736                                    DIFF_STATUS_ADDED)
 737                                        added = 0;
 738                        if (added)
 739                                printf("%snew file mode %06o",
 740                                       c_meta, elem->mode);
 741                        else {
 742                                if (!elem->mode)
 743                                        printf("%sdeleted file ", c_meta);
 744                                printf("mode ");
 745                                for (i = 0; i < num_parent; i++) {
 746                                        printf("%s%06o", i ? "," : "",
 747                                               elem->parent[i].mode);
 748                                }
 749                                if (elem->mode)
 750                                        printf("..%06o", elem->mode);
 751                        }
 752                        printf("%s\n", c_reset);
 753                }
 754                dump_quoted_path("--- a/", elem->path, c_meta, c_reset);
 755                dump_quoted_path("+++ b/", elem->path, c_meta, c_reset);
 756                dump_sline(sline, cnt, num_parent, opt->color_diff);
 757        }
 758        free(result);
 759
 760        for (lno = 0; lno < cnt; lno++) {
 761                if (sline[lno].lost_head) {
 762                        struct lline *ll = sline[lno].lost_head;
 763                        while (ll) {
 764                                struct lline *tmp = ll;
 765                                ll = ll->next;
 766                                free(tmp);
 767                        }
 768                }
 769        }
 770        free(sline[0].p_lno);
 771        free(sline);
 772        return shown_header;
 773}
 774
 775#define COLONS "::::::::::::::::::::::::::::::::"
 776
 777static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
 778{
 779        struct diff_options *opt = &rev->diffopt;
 780        int i, offset;
 781        const char *prefix;
 782        int line_termination, inter_name_termination;
 783
 784        line_termination = opt->line_termination;
 785        inter_name_termination = '\t';
 786        if (!line_termination)
 787                inter_name_termination = 0;
 788
 789        if (rev->loginfo)
 790                show_log(rev, opt->msg_sep);
 791
 792        if (opt->output_format & DIFF_FORMAT_RAW) {
 793                offset = strlen(COLONS) - num_parent;
 794                if (offset < 0)
 795                        offset = 0;
 796                prefix = COLONS + offset;
 797
 798                /* Show the modes */
 799                for (i = 0; i < num_parent; i++) {
 800                        printf("%s%06o", prefix, p->parent[i].mode);
 801                        prefix = " ";
 802                }
 803                printf("%s%06o", prefix, p->mode);
 804
 805                /* Show sha1's */
 806                for (i = 0; i < num_parent; i++)
 807                        printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
 808                                                         opt->abbrev));
 809                printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
 810        }
 811
 812        if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
 813                for (i = 0; i < num_parent; i++)
 814                        putchar(p->parent[i].status);
 815                putchar(inter_name_termination);
 816        }
 817
 818        if (line_termination) {
 819                if (quote_c_style(p->path, NULL, NULL, 0))
 820                        quote_c_style(p->path, NULL, stdout, 0);
 821                else
 822                        printf("%s", p->path);
 823                putchar(line_termination);
 824        }
 825        else {
 826                printf("%s%c", p->path, line_termination);
 827        }
 828}
 829
 830void show_combined_diff(struct combine_diff_path *p,
 831                       int num_parent,
 832                       int dense,
 833                       struct rev_info *rev)
 834{
 835        struct diff_options *opt = &rev->diffopt;
 836        if (!p->len)
 837                return;
 838        if (opt->output_format & (DIFF_FORMAT_RAW |
 839                                  DIFF_FORMAT_NAME |
 840                                  DIFF_FORMAT_NAME_STATUS)) {
 841                show_raw_diff(p, num_parent, rev);
 842        } else if (opt->output_format & DIFF_FORMAT_PATCH) {
 843                show_patch_diff(p, num_parent, dense, rev);
 844        }
 845}
 846
 847void diff_tree_combined(const unsigned char *sha1,
 848                        const unsigned char parent[][20],
 849                        int num_parent,
 850                        int dense,
 851                        struct rev_info *rev)
 852{
 853        struct diff_options *opt = &rev->diffopt;
 854        struct diff_options diffopts;
 855        struct combine_diff_path *p, *paths = NULL;
 856        int i, num_paths, needsep, show_log_first;
 857
 858        diffopts = *opt;
 859        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
 860        diffopts.recursive = 1;
 861
 862        show_log_first = !!rev->loginfo;
 863        needsep = 0;
 864        /* find set of paths that everybody touches */
 865        for (i = 0; i < num_parent; i++) {
 866                /* show stat against the first parent even
 867                 * when doing combined diff.
 868                 */
 869                if (i == 0 && opt->output_format & DIFF_FORMAT_DIFFSTAT)
 870                        diffopts.output_format = DIFF_FORMAT_DIFFSTAT;
 871                else
 872                        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
 873                diff_tree_sha1(parent[i], sha1, "", &diffopts);
 874                diffcore_std(&diffopts);
 875                paths = intersect_paths(paths, i, num_parent);
 876
 877                if (show_log_first && i == 0) {
 878                        show_log(rev, opt->msg_sep);
 879                        if (rev->verbose_header && opt->output_format)
 880                                putchar(opt->line_termination);
 881                }
 882                diff_flush(&diffopts);
 883        }
 884
 885        /* find out surviving paths */
 886        for (num_paths = 0, p = paths; p; p = p->next) {
 887                if (p->len)
 888                        num_paths++;
 889        }
 890        if (num_paths) {
 891                if (opt->output_format & (DIFF_FORMAT_RAW |
 892                                          DIFF_FORMAT_NAME |
 893                                          DIFF_FORMAT_NAME_STATUS)) {
 894                        for (p = paths; p; p = p->next) {
 895                                if (p->len)
 896                                        show_raw_diff(p, num_parent, rev);
 897                        }
 898                        needsep = 1;
 899                }
 900                else if (opt->output_format & DIFF_FORMAT_DIFFSTAT)
 901                        needsep = 1;
 902                if (opt->output_format & DIFF_FORMAT_PATCH) {
 903                        if (needsep)
 904                                putchar(opt->line_termination);
 905                        for (p = paths; p; p = p->next) {
 906                                if (p->len)
 907                                        show_patch_diff(p, num_parent, dense,
 908                                                        rev);
 909                        }
 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}
 920
 921void diff_tree_combined_merge(const unsigned char *sha1,
 922                             int dense, struct rev_info *rev)
 923{
 924        int num_parent;
 925        const unsigned char (*parent)[20];
 926        struct commit *commit = lookup_commit(sha1);
 927        struct commit_list *parents;
 928
 929        /* count parents */
 930        for (parents = commit->parents, num_parent = 0;
 931             parents;
 932             parents = parents->next, num_parent++)
 933                ; /* nothing */
 934
 935        parent = xmalloc(num_parent * sizeof(*parent));
 936        for (parents = commit->parents, num_parent = 0;
 937             parents;
 938             parents = parents->next, num_parent++)
 939                memcpy(parent + num_parent, parents->item->object.sha1, 20);
 940        diff_tree_combined(sha1, parent, num_parent, dense, rev);
 941}