combine-diff.con commit Merge branch 'rj/maint-1.6.0-svn-parse-fix' into maint (54e0e6e)
   1#include "cache.h"
   2#include "commit.h"
   3#include "blob.h"
   4#include "diff.h"
   5#include "diffcore.h"
   6#include "quote.h"
   7#include "xdiff-interface.h"
   8#include "log-tree.h"
   9#include "refs.h"
  10
  11static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
  12{
  13        struct diff_queue_struct *q = &diff_queued_diff;
  14        struct combine_diff_path *p;
  15        int i;
  16
  17        if (!n) {
  18                struct combine_diff_path *list = NULL, **tail = &list;
  19                for (i = 0; i < q->nr; i++) {
  20                        int len;
  21                        const char *path;
  22                        if (diff_unmodified_pair(q->queue[i]))
  23                                continue;
  24                        path = q->queue[i]->two->path;
  25                        len = strlen(path);
  26                        p = xmalloc(combine_diff_path_size(num_parent, len));
  27                        p->path = (char*) &(p->parent[num_parent]);
  28                        memcpy(p->path, path, len);
  29                        p->path[len] = 0;
  30                        p->len = len;
  31                        p->next = NULL;
  32                        memset(p->parent, 0,
  33                               sizeof(p->parent[0]) * num_parent);
  34
  35                        hashcpy(p->sha1, q->queue[i]->two->sha1);
  36                        p->mode = q->queue[i]->two->mode;
  37                        hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
  38                        p->parent[n].mode = q->queue[i]->one->mode;
  39                        p->parent[n].status = q->queue[i]->status;
  40                        *tail = p;
  41                        tail = &p->next;
  42                }
  43                return list;
  44        }
  45
  46        for (p = curr; p; p = p->next) {
  47                int found = 0;
  48                if (!p->len)
  49                        continue;
  50                for (i = 0; i < q->nr; i++) {
  51                        const char *path;
  52                        int len;
  53
  54                        if (diff_unmodified_pair(q->queue[i]))
  55                                continue;
  56                        path = q->queue[i]->two->path;
  57                        len = strlen(path);
  58                        if (len == p->len && !memcmp(path, p->path, len)) {
  59                                found = 1;
  60                                hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
  61                                p->parent[n].mode = q->queue[i]->one->mode;
  62                                p->parent[n].status = q->queue[i]->status;
  63                                break;
  64                        }
  65                }
  66                if (!found)
  67                        p->len = 0;
  68        }
  69        return curr;
  70}
  71
  72/* Lines lost from parent */
  73struct lline {
  74        struct lline *next;
  75        int len;
  76        unsigned long parent_map;
  77        char line[FLEX_ARRAY];
  78};
  79
  80/* Lines surviving in the merge result */
  81struct sline {
  82        struct lline *lost_head, **lost_tail;
  83        char *bol;
  84        int len;
  85        /* bit 0 up to (N-1) are on if the parent has this line (i.e.
  86         * we did not change it).
  87         * bit N is used for "interesting" lines, including context.
  88         * bit (N+1) is used for "do not show deletion before this".
  89         */
  90        unsigned long flag;
  91        unsigned long *p_lno;
  92};
  93
  94static char *grab_blob(const unsigned char *sha1, unsigned int mode, unsigned long *size)
  95{
  96        char *blob;
  97        enum object_type type;
  98
  99        if (S_ISGITLINK(mode)) {
 100                blob = xmalloc(100);
 101                *size = snprintf(blob, 100,
 102                                 "Subproject commit %s\n", sha1_to_hex(sha1));
 103        } else if (is_null_sha1(sha1)) {
 104                /* deleted blob */
 105                *size = 0;
 106                return xcalloc(1, 1);
 107        } else {
 108                blob = read_sha1_file(sha1, &type, size);
 109                if (type != OBJ_BLOB)
 110                        die("object '%s' is not a blob!", sha1_to_hex(sha1));
 111        }
 112        return blob;
 113}
 114
 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        unsigned int lno;
 154        int ob, on, nb, nn;
 155        unsigned long nmask;
 156        int num_parent;
 157        int n;
 158        struct sline *sline;
 159        struct sline *lost_bucket;
 160};
 161
 162static void consume_line(void *state_, char *line, unsigned long len)
 163{
 164        struct combine_diff_state *state = state_;
 165        if (5 < len && !memcmp("@@ -", line, 4)) {
 166                if (parse_hunk_header(line, len,
 167                                      &state->ob, &state->on,
 168                                      &state->nb, &state->nn))
 169                        return;
 170                state->lno = state->nb;
 171                if (!state->nb)
 172                        /* @@ -1,2 +0,0 @@ to remove the
 173                         * first two lines...
 174                         */
 175                        state->nb = 1;
 176                if (state->nn == 0)
 177                        /* @@ -X,Y +N,0 @@ removed Y lines
 178                         * that would have come *after* line N
 179                         * in the result.  Our lost buckets hang
 180                         * to the line after the removed lines,
 181                         */
 182                        state->lost_bucket = &state->sline[state->nb];
 183                else
 184                        state->lost_bucket = &state->sline[state->nb-1];
 185                if (!state->sline[state->nb-1].p_lno)
 186                        state->sline[state->nb-1].p_lno =
 187                                xcalloc(state->num_parent,
 188                                        sizeof(unsigned long));
 189                state->sline[state->nb-1].p_lno[state->n] = state->ob;
 190                return;
 191        }
 192        if (!state->lost_bucket)
 193                return; /* not in any hunk yet */
 194        switch (line[0]) {
 195        case '-':
 196                append_lost(state->lost_bucket, state->n, line+1, len-1);
 197                break;
 198        case '+':
 199                state->sline[state->lno-1].flag |= state->nmask;
 200                state->lno++;
 201                break;
 202        }
 203}
 204
 205static void combine_diff(const unsigned char *parent, unsigned int mode,
 206                         mmfile_t *result_file,
 207                         struct sline *sline, unsigned int cnt, int n,
 208                         int num_parent)
 209{
 210        unsigned int p_lno, lno;
 211        unsigned long nmask = (1UL << n);
 212        xpparam_t xpp;
 213        xdemitconf_t xecfg;
 214        mmfile_t parent_file;
 215        xdemitcb_t ecb;
 216        struct combine_diff_state state;
 217        unsigned long sz;
 218
 219        if (!cnt)
 220                return; /* result deleted */
 221
 222        parent_file.ptr = grab_blob(parent, mode, &sz);
 223        parent_file.size = sz;
 224        memset(&xpp, 0, sizeof(xpp));
 225        xpp.flags = XDF_NEED_MINIMAL;
 226        memset(&xecfg, 0, sizeof(xecfg));
 227        memset(&state, 0, sizeof(state));
 228        state.nmask = nmask;
 229        state.sline = sline;
 230        state.lno = 1;
 231        state.num_parent = num_parent;
 232        state.n = n;
 233
 234        xdi_diff_outf(&parent_file, result_file, consume_line, &state,
 235                      &xpp, &xecfg, &ecb);
 236        free(parent_file.ptr);
 237
 238        /* Assign line numbers for this parent.
 239         *
 240         * sline[lno].p_lno[n] records the first line number
 241         * (counting from 1) for parent N if the final hunk display
 242         * started by showing sline[lno] (possibly showing the lost
 243         * lines attached to it first).
 244         */
 245        for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
 246                struct lline *ll;
 247                sline[lno].p_lno[n] = p_lno;
 248
 249                /* How many lines would this sline advance the p_lno? */
 250                ll = sline[lno].lost_head;
 251                while (ll) {
 252                        if (ll->parent_map & nmask)
 253                                p_lno++; /* '-' means parent had it */
 254                        ll = ll->next;
 255                }
 256                if (lno < cnt && !(sline[lno].flag & nmask))
 257                        p_lno++; /* no '+' means parent had it */
 258        }
 259        sline[lno].p_lno[n] = p_lno; /* trailer */
 260}
 261
 262static unsigned long context = 3;
 263static char combine_marker = '@';
 264
 265static int interesting(struct sline *sline, unsigned long all_mask)
 266{
 267        /* If some parents lost lines here, or if we have added to
 268         * some parent, it is interesting.
 269         */
 270        return ((sline->flag & all_mask) || sline->lost_head);
 271}
 272
 273static unsigned long adjust_hunk_tail(struct sline *sline,
 274                                      unsigned long all_mask,
 275                                      unsigned long hunk_begin,
 276                                      unsigned long i)
 277{
 278        /* i points at the first uninteresting line.  If the last line
 279         * of the hunk was interesting only because it has some
 280         * deletion, then it is not all that interesting for the
 281         * purpose of giving trailing context lines.  This is because
 282         * we output '-' line and then unmodified sline[i-1] itself in
 283         * that case which gives us one extra context line.
 284         */
 285        if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
 286                i--;
 287        return i;
 288}
 289
 290static unsigned long find_next(struct sline *sline,
 291                               unsigned long mark,
 292                               unsigned long i,
 293                               unsigned long cnt,
 294                               int look_for_uninteresting)
 295{
 296        /* We have examined up to i-1 and are about to look at i.
 297         * Find next interesting or uninteresting line.  Here,
 298         * "interesting" does not mean interesting(), but marked by
 299         * the give_context() function below (i.e. it includes context
 300         * lines that are not interesting to interesting() function
 301         * that are surrounded by interesting() ones.
 302         */
 303        while (i <= cnt)
 304                if (look_for_uninteresting
 305                    ? !(sline[i].flag & mark)
 306                    : (sline[i].flag & mark))
 307                        return i;
 308                else
 309                        i++;
 310        return i;
 311}
 312
 313static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 314{
 315        unsigned long all_mask = (1UL<<num_parent) - 1;
 316        unsigned long mark = (1UL<<num_parent);
 317        unsigned long no_pre_delete = (2UL<<num_parent);
 318        unsigned long i;
 319
 320        /* Two groups of interesting lines may have a short gap of
 321         * uninteresting lines.  Connect such groups to give them a
 322         * bit of context.
 323         *
 324         * We first start from what the interesting() function says,
 325         * and mark them with "mark", and paint context lines with the
 326         * mark.  So interesting() would still say false for such context
 327         * lines but they are treated as "interesting" in the end.
 328         */
 329        i = find_next(sline, mark, 0, cnt, 0);
 330        if (cnt < i)
 331                return 0;
 332
 333        while (i <= cnt) {
 334                unsigned long j = (context < i) ? (i - context) : 0;
 335                unsigned long k;
 336
 337                /* Paint a few lines before the first interesting line. */
 338                while (j < i)
 339                        sline[j++].flag |= mark | no_pre_delete;
 340
 341        again:
 342                /* we know up to i is to be included.  where does the
 343                 * next uninteresting one start?
 344                 */
 345                j = find_next(sline, mark, i, cnt, 1);
 346                if (cnt < j)
 347                        break; /* the rest are all interesting */
 348
 349                /* lookahead context lines */
 350                k = find_next(sline, mark, j, cnt, 0);
 351                j = adjust_hunk_tail(sline, all_mask, i, j);
 352
 353                if (k < j + context) {
 354                        /* k is interesting and [j,k) are not, but
 355                         * paint them interesting because the gap is small.
 356                         */
 357                        while (j < k)
 358                                sline[j++].flag |= mark;
 359                        i = k;
 360                        goto again;
 361                }
 362
 363                /* j is the first uninteresting line and there is
 364                 * no overlap beyond it within context lines.  Paint
 365                 * the trailing edge a bit.
 366                 */
 367                i = k;
 368                k = (j + context < cnt+1) ? j + context : cnt+1;
 369                while (j < k)
 370                        sline[j++].flag |= mark;
 371        }
 372        return 1;
 373}
 374
 375static int make_hunks(struct sline *sline, unsigned long cnt,
 376                       int num_parent, int dense)
 377{
 378        unsigned long all_mask = (1UL<<num_parent) - 1;
 379        unsigned long mark = (1UL<<num_parent);
 380        unsigned long i;
 381        int has_interesting = 0;
 382
 383        for (i = 0; i <= cnt; i++) {
 384                if (interesting(&sline[i], all_mask))
 385                        sline[i].flag |= mark;
 386                else
 387                        sline[i].flag &= ~mark;
 388        }
 389        if (!dense)
 390                return give_context(sline, cnt, num_parent);
 391
 392        /* Look at each hunk, and if we have changes from only one
 393         * parent, or the changes are the same from all but one
 394         * parent, mark that uninteresting.
 395         */
 396        i = 0;
 397        while (i <= cnt) {
 398                unsigned long j, hunk_begin, hunk_end;
 399                unsigned long same_diff;
 400                while (i <= cnt && !(sline[i].flag & mark))
 401                        i++;
 402                if (cnt < i)
 403                        break; /* No more interesting hunks */
 404                hunk_begin = i;
 405                for (j = i + 1; j <= cnt; j++) {
 406                        if (!(sline[j].flag & mark)) {
 407                                /* Look beyond the end to see if there
 408                                 * is an interesting line after this
 409                                 * hunk within context span.
 410                                 */
 411                                unsigned long la; /* lookahead */
 412                                int contin = 0;
 413                                la = adjust_hunk_tail(sline, all_mask,
 414                                                     hunk_begin, j);
 415                                la = (la + context < cnt + 1) ?
 416                                        (la + context) : cnt + 1;
 417                                while (j <= --la) {
 418                                        if (sline[la].flag & mark) {
 419                                                contin = 1;
 420                                                break;
 421                                        }
 422                                }
 423                                if (!contin)
 424                                        break;
 425                                j = la;
 426                        }
 427                }
 428                hunk_end = j;
 429
 430                /* [i..hunk_end) are interesting.  Now is it really
 431                 * interesting?  We check if there are only two versions
 432                 * and the result matches one of them.  That is, we look
 433                 * at:
 434                 *   (+) line, which records lines added to which parents;
 435                 *       this line appears in the result.
 436                 *   (-) line, which records from what parents the line
 437                 *       was removed; this line does not appear in the result.
 438                 * then check the set of parents the result has difference
 439                 * from, from all lines.  If there are lines that has
 440                 * different set of parents that the result has differences
 441                 * from, that means we have more than two versions.
 442                 *
 443                 * Even when we have only two versions, if the result does
 444                 * not match any of the parents, the it should be considered
 445                 * interesting.  In such a case, we would have all '+' line.
 446                 * After passing the above "two versions" test, that would
 447                 * appear as "the same set of parents" to be "all parents".
 448                 */
 449                same_diff = 0;
 450                has_interesting = 0;
 451                for (j = i; j < hunk_end && !has_interesting; j++) {
 452                        unsigned long this_diff = sline[j].flag & all_mask;
 453                        struct lline *ll = sline[j].lost_head;
 454                        if (this_diff) {
 455                                /* This has some changes.  Is it the
 456                                 * same as others?
 457                                 */
 458                                if (!same_diff)
 459                                        same_diff = this_diff;
 460                                else if (same_diff != this_diff) {
 461                                        has_interesting = 1;
 462                                        break;
 463                                }
 464                        }
 465                        while (ll && !has_interesting) {
 466                                /* Lost this line from these parents;
 467                                 * who are they?  Are they the same?
 468                                 */
 469                                this_diff = ll->parent_map;
 470                                if (!same_diff)
 471                                        same_diff = this_diff;
 472                                else if (same_diff != this_diff) {
 473                                        has_interesting = 1;
 474                                }
 475                                ll = ll->next;
 476                        }
 477                }
 478
 479                if (!has_interesting && same_diff != all_mask) {
 480                        /* This hunk is not that interesting after all */
 481                        for (j = hunk_begin; j < hunk_end; j++)
 482                                sline[j].flag &= ~mark;
 483                }
 484                i = hunk_end;
 485        }
 486
 487        has_interesting = give_context(sline, cnt, num_parent);
 488        return has_interesting;
 489}
 490
 491static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
 492{
 493        l0 = sline[l0].p_lno[n];
 494        l1 = sline[l1].p_lno[n];
 495        printf(" -%lu,%lu", l0, l1-l0-null_context);
 496}
 497
 498static int hunk_comment_line(const char *bol)
 499{
 500        int ch;
 501
 502        if (!bol)
 503                return 0;
 504        ch = *bol & 0xff;
 505        return (isalpha(ch) || ch == '_' || ch == '$');
 506}
 507
 508static void show_line_to_eol(const char *line, int len, const char *reset)
 509{
 510        int saw_cr_at_eol = 0;
 511        if (len < 0)
 512                len = strlen(line);
 513        saw_cr_at_eol = (len && line[len-1] == '\r');
 514
 515        printf("%.*s%s%s\n", len - saw_cr_at_eol, line,
 516               reset,
 517               saw_cr_at_eol ? "\r" : "");
 518}
 519
 520static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 521                       int use_color)
 522{
 523        unsigned long mark = (1UL<<num_parent);
 524        unsigned long no_pre_delete = (2UL<<num_parent);
 525        int i;
 526        unsigned long lno = 0;
 527        const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
 528        const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
 529        const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
 530        const char *c_plain = diff_get_color(use_color, DIFF_PLAIN);
 531        const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 532
 533        if (!cnt)
 534                return; /* result deleted */
 535
 536        while (1) {
 537                struct sline *sl = &sline[lno];
 538                unsigned long hunk_end;
 539                unsigned long rlines;
 540                const char *hunk_comment = NULL;
 541                unsigned long null_context = 0;
 542
 543                while (lno <= cnt && !(sline[lno].flag & mark)) {
 544                        if (hunk_comment_line(sline[lno].bol))
 545                                hunk_comment = sline[lno].bol;
 546                        lno++;
 547                }
 548                if (cnt < lno)
 549                        break;
 550                else {
 551                        for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
 552                                if (!(sline[hunk_end].flag & mark))
 553                                        break;
 554                }
 555                rlines = hunk_end - lno;
 556                if (cnt < hunk_end)
 557                        rlines--; /* pointing at the last delete hunk */
 558
 559                if (!context) {
 560                        /*
 561                         * Even when running with --unified=0, all
 562                         * lines in the hunk needs to be processed in
 563                         * the loop below in order to show the
 564                         * deletion recorded in lost_head.  However,
 565                         * we do not want to show the resulting line
 566                         * with all blank context markers in such a
 567                         * case.  Compensate.
 568                         */
 569                        unsigned long j;
 570                        for (j = lno; j < hunk_end; j++)
 571                                if (!(sline[j].flag & (mark-1)))
 572                                        null_context++;
 573                        rlines -= null_context;
 574                }
 575
 576                fputs(c_frag, stdout);
 577                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 578                for (i = 0; i < num_parent; i++)
 579                        show_parent_lno(sline, lno, hunk_end, i, null_context);
 580                printf(" +%lu,%lu ", lno+1, rlines);
 581                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 582
 583                if (hunk_comment) {
 584                        int comment_end = 0;
 585                        for (i = 0; i < 40; i++) {
 586                                int ch = hunk_comment[i] & 0xff;
 587                                if (!ch || ch == '\n')
 588                                        break;
 589                                if (!isspace(ch))
 590                                    comment_end = i;
 591                        }
 592                        if (comment_end)
 593                                putchar(' ');
 594                        for (i = 0; i < comment_end; i++)
 595                                putchar(hunk_comment[i]);
 596                }
 597
 598                printf("%s\n", c_reset);
 599                while (lno < hunk_end) {
 600                        struct lline *ll;
 601                        int j;
 602                        unsigned long p_mask;
 603                        sl = &sline[lno++];
 604                        ll = (sl->flag & no_pre_delete) ? NULL : sl->lost_head;
 605                        while (ll) {
 606                                fputs(c_old, stdout);
 607                                for (j = 0; j < num_parent; j++) {
 608                                        if (ll->parent_map & (1UL<<j))
 609                                                putchar('-');
 610                                        else
 611                                                putchar(' ');
 612                                }
 613                                show_line_to_eol(ll->line, -1, c_reset);
 614                                ll = ll->next;
 615                        }
 616                        if (cnt < lno)
 617                                break;
 618                        p_mask = 1;
 619                        if (!(sl->flag & (mark-1))) {
 620                                /*
 621                                 * This sline was here to hang the
 622                                 * lost lines in front of it.
 623                                 */
 624                                if (!context)
 625                                        continue;
 626                                fputs(c_plain, stdout);
 627                        }
 628                        else
 629                                fputs(c_new, stdout);
 630                        for (j = 0; j < num_parent; j++) {
 631                                if (p_mask & sl->flag)
 632                                        putchar('+');
 633                                else
 634                                        putchar(' ');
 635                                p_mask <<= 1;
 636                        }
 637                        show_line_to_eol(sl->bol, sl->len, c_reset);
 638                }
 639        }
 640}
 641
 642static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 643                               int i, int j)
 644{
 645        /* We have already examined parent j and we know parent i
 646         * and parent j are the same, so reuse the combined result
 647         * of parent j for parent i.
 648         */
 649        unsigned long lno, imask, jmask;
 650        imask = (1UL<<i);
 651        jmask = (1UL<<j);
 652
 653        for (lno = 0; lno <= cnt; lno++) {
 654                struct lline *ll = sline->lost_head;
 655                sline->p_lno[i] = sline->p_lno[j];
 656                while (ll) {
 657                        if (ll->parent_map & jmask)
 658                                ll->parent_map |= imask;
 659                        ll = ll->next;
 660                }
 661                if (sline->flag & jmask)
 662                        sline->flag |= imask;
 663                sline++;
 664        }
 665        /* the overall size of the file (sline[cnt]) */
 666        sline->p_lno[i] = sline->p_lno[j];
 667}
 668
 669static void dump_quoted_path(const char *head,
 670                             const char *prefix,
 671                             const char *path,
 672                             const char *c_meta, const char *c_reset)
 673{
 674        static struct strbuf buf = STRBUF_INIT;
 675
 676        strbuf_reset(&buf);
 677        strbuf_addstr(&buf, c_meta);
 678        strbuf_addstr(&buf, head);
 679        quote_two_c_style(&buf, prefix, path, 0);
 680        strbuf_addstr(&buf, c_reset);
 681        puts(buf.buf);
 682}
 683
 684static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 685                            int dense, struct rev_info *rev)
 686{
 687        struct diff_options *opt = &rev->diffopt;
 688        unsigned long result_size, cnt, lno;
 689        char *result, *cp;
 690        struct sline *sline; /* survived lines */
 691        int mode_differs = 0;
 692        int i, show_hunks;
 693        int working_tree_file = is_null_sha1(elem->sha1);
 694        int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
 695        const char *a_prefix, *b_prefix;
 696        mmfile_t result_file;
 697
 698        context = opt->context;
 699        a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
 700        b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
 701
 702        /* Read the result of merge first */
 703        if (!working_tree_file)
 704                result = grab_blob(elem->sha1, elem->mode, &result_size);
 705        else {
 706                /* Used by diff-tree to read from the working tree */
 707                struct stat st;
 708                int fd = -1;
 709
 710                if (lstat(elem->path, &st) < 0)
 711                        goto deleted_file;
 712
 713                if (S_ISLNK(st.st_mode)) {
 714                        struct strbuf buf = STRBUF_INIT;
 715
 716                        if (strbuf_readlink(&buf, elem->path, st.st_size) < 0) {
 717                                error("readlink(%s): %s", elem->path,
 718                                      strerror(errno));
 719                                return;
 720                        }
 721                        result_size = buf.len;
 722                        result = strbuf_detach(&buf, NULL);
 723                        elem->mode = canon_mode(st.st_mode);
 724                } else if (S_ISDIR(st.st_mode)) {
 725                        unsigned char sha1[20];
 726                        if (resolve_gitlink_ref(elem->path, "HEAD", sha1) < 0)
 727                                result = grab_blob(elem->sha1, elem->mode, &result_size);
 728                        else
 729                                result = grab_blob(sha1, elem->mode, &result_size);
 730                } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
 731                        size_t len = xsize_t(st.st_size);
 732                        ssize_t done;
 733                        int is_file, i;
 734
 735                        elem->mode = canon_mode(st.st_mode);
 736                        /* if symlinks don't work, assume symlink if all parents
 737                         * are symlinks
 738                         */
 739                        is_file = has_symlinks;
 740                        for (i = 0; !is_file && i < num_parent; i++)
 741                                is_file = !S_ISLNK(elem->parent[i].mode);
 742                        if (!is_file)
 743                                elem->mode = canon_mode(S_IFLNK);
 744
 745                        result_size = len;
 746                        result = xmalloc(len + 1);
 747
 748                        done = read_in_full(fd, result, len);
 749                        if (done < 0)
 750                                die("read error '%s'", elem->path);
 751                        else if (done < len)
 752                                die("early EOF '%s'", elem->path);
 753
 754                        result[len] = 0;
 755
 756                        /* If not a fake symlink, apply filters, e.g. autocrlf */
 757                        if (is_file) {
 758                                struct strbuf buf = STRBUF_INIT;
 759
 760                                if (convert_to_git(elem->path, result, len, &buf, safe_crlf)) {
 761                                        free(result);
 762                                        result = strbuf_detach(&buf, &len);
 763                                        result_size = len;
 764                                }
 765                        }
 766                }
 767                else {
 768                deleted_file:
 769                        result_size = 0;
 770                        elem->mode = 0;
 771                        result = xcalloc(1, 1);
 772                }
 773
 774                if (0 <= fd)
 775                        close(fd);
 776        }
 777
 778        for (cnt = 0, cp = result; cp < result + result_size; cp++) {
 779                if (*cp == '\n')
 780                        cnt++;
 781        }
 782        if (result_size && result[result_size-1] != '\n')
 783                cnt++; /* incomplete line */
 784
 785        sline = xcalloc(cnt+2, sizeof(*sline));
 786        sline[0].bol = result;
 787        for (lno = 0; lno <= cnt + 1; lno++) {
 788                sline[lno].lost_tail = &sline[lno].lost_head;
 789                sline[lno].flag = 0;
 790        }
 791        for (lno = 0, cp = result; cp < result + result_size; cp++) {
 792                if (*cp == '\n') {
 793                        sline[lno].len = cp - sline[lno].bol;
 794                        lno++;
 795                        if (lno < cnt)
 796                                sline[lno].bol = cp + 1;
 797                }
 798        }
 799        if (result_size && result[result_size-1] != '\n')
 800                sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
 801
 802        result_file.ptr = result;
 803        result_file.size = result_size;
 804
 805        /* Even p_lno[cnt+1] is valid -- that is for the end line number
 806         * for deletion hunk at the end.
 807         */
 808        sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
 809        for (lno = 0; lno <= cnt; lno++)
 810                sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
 811
 812        for (i = 0; i < num_parent; i++) {
 813                int j;
 814                for (j = 0; j < i; j++) {
 815                        if (!hashcmp(elem->parent[i].sha1,
 816                                     elem->parent[j].sha1)) {
 817                                reuse_combine_diff(sline, cnt, i, j);
 818                                break;
 819                        }
 820                }
 821                if (i <= j)
 822                        combine_diff(elem->parent[i].sha1,
 823                                     elem->parent[i].mode,
 824                                     &result_file, sline,
 825                                     cnt, i, num_parent);
 826                if (elem->parent[i].mode != elem->mode)
 827                        mode_differs = 1;
 828        }
 829
 830        show_hunks = make_hunks(sline, cnt, num_parent, dense);
 831
 832        if (show_hunks || mode_differs || working_tree_file) {
 833                const char *abb;
 834                int use_color = DIFF_OPT_TST(opt, COLOR_DIFF);
 835                const char *c_meta = diff_get_color(use_color, DIFF_METAINFO);
 836                const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 837                int added = 0;
 838                int deleted = 0;
 839
 840                if (rev->loginfo && !rev->no_commit_id)
 841                        show_log(rev);
 842                dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
 843                                 "", elem->path, c_meta, c_reset);
 844                printf("%sindex ", c_meta);
 845                for (i = 0; i < num_parent; i++) {
 846                        abb = find_unique_abbrev(elem->parent[i].sha1,
 847                                                 abbrev);
 848                        printf("%s%s", i ? "," : "", abb);
 849                }
 850                abb = find_unique_abbrev(elem->sha1, abbrev);
 851                printf("..%s%s\n", abb, c_reset);
 852
 853                if (mode_differs) {
 854                        deleted = !elem->mode;
 855
 856                        /* We say it was added if nobody had it */
 857                        added = !deleted;
 858                        for (i = 0; added && i < num_parent; i++)
 859                                if (elem->parent[i].status !=
 860                                    DIFF_STATUS_ADDED)
 861                                        added = 0;
 862                        if (added)
 863                                printf("%snew file mode %06o",
 864                                       c_meta, elem->mode);
 865                        else {
 866                                if (deleted)
 867                                        printf("%sdeleted file ", c_meta);
 868                                printf("mode ");
 869                                for (i = 0; i < num_parent; i++) {
 870                                        printf("%s%06o", i ? "," : "",
 871                                               elem->parent[i].mode);
 872                                }
 873                                if (elem->mode)
 874                                        printf("..%06o", elem->mode);
 875                        }
 876                        printf("%s\n", c_reset);
 877                }
 878                if (added)
 879                        dump_quoted_path("--- ", "", "/dev/null",
 880                                         c_meta, c_reset);
 881                else
 882                        dump_quoted_path("--- ", a_prefix, elem->path,
 883                                         c_meta, c_reset);
 884                if (deleted)
 885                        dump_quoted_path("+++ ", "", "/dev/null",
 886                                         c_meta, c_reset);
 887                else
 888                        dump_quoted_path("+++ ", b_prefix, elem->path,
 889                                         c_meta, c_reset);
 890                dump_sline(sline, cnt, num_parent,
 891                           DIFF_OPT_TST(opt, COLOR_DIFF));
 892        }
 893        free(result);
 894
 895        for (lno = 0; lno < cnt; lno++) {
 896                if (sline[lno].lost_head) {
 897                        struct lline *ll = sline[lno].lost_head;
 898                        while (ll) {
 899                                struct lline *tmp = ll;
 900                                ll = ll->next;
 901                                free(tmp);
 902                        }
 903                }
 904        }
 905        free(sline[0].p_lno);
 906        free(sline);
 907}
 908
 909#define COLONS "::::::::::::::::::::::::::::::::"
 910
 911static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
 912{
 913        struct diff_options *opt = &rev->diffopt;
 914        int i, offset;
 915        const char *prefix;
 916        int line_termination, inter_name_termination;
 917
 918        line_termination = opt->line_termination;
 919        inter_name_termination = '\t';
 920        if (!line_termination)
 921                inter_name_termination = 0;
 922
 923        if (rev->loginfo && !rev->no_commit_id)
 924                show_log(rev);
 925
 926        if (opt->output_format & DIFF_FORMAT_RAW) {
 927                offset = strlen(COLONS) - num_parent;
 928                if (offset < 0)
 929                        offset = 0;
 930                prefix = COLONS + offset;
 931
 932                /* Show the modes */
 933                for (i = 0; i < num_parent; i++) {
 934                        printf("%s%06o", prefix, p->parent[i].mode);
 935                        prefix = " ";
 936                }
 937                printf("%s%06o", prefix, p->mode);
 938
 939                /* Show sha1's */
 940                for (i = 0; i < num_parent; i++)
 941                        printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
 942                                                         opt->abbrev));
 943                printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
 944        }
 945
 946        if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
 947                for (i = 0; i < num_parent; i++)
 948                        putchar(p->parent[i].status);
 949                putchar(inter_name_termination);
 950        }
 951
 952        write_name_quoted(p->path, stdout, line_termination);
 953}
 954
 955void show_combined_diff(struct combine_diff_path *p,
 956                       int num_parent,
 957                       int dense,
 958                       struct rev_info *rev)
 959{
 960        struct diff_options *opt = &rev->diffopt;
 961        if (!p->len)
 962                return;
 963        if (opt->output_format & (DIFF_FORMAT_RAW |
 964                                  DIFF_FORMAT_NAME |
 965                                  DIFF_FORMAT_NAME_STATUS))
 966                show_raw_diff(p, num_parent, rev);
 967        else if (opt->output_format & DIFF_FORMAT_PATCH)
 968                show_patch_diff(p, num_parent, dense, rev);
 969}
 970
 971void diff_tree_combined(const unsigned char *sha1,
 972                        const unsigned char parent[][20],
 973                        int num_parent,
 974                        int dense,
 975                        struct rev_info *rev)
 976{
 977        struct diff_options *opt = &rev->diffopt;
 978        struct diff_options diffopts;
 979        struct combine_diff_path *p, *paths = NULL;
 980        int i, num_paths, needsep, show_log_first;
 981
 982        diffopts = *opt;
 983        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
 984        DIFF_OPT_SET(&diffopts, RECURSIVE);
 985        DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
 986
 987        show_log_first = !!rev->loginfo && !rev->no_commit_id;
 988        needsep = 0;
 989        /* find set of paths that everybody touches */
 990        for (i = 0; i < num_parent; i++) {
 991                /* show stat against the first parent even
 992                 * when doing combined diff.
 993                 */
 994                int stat_opt = (opt->output_format &
 995                                (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
 996                if (i == 0 && stat_opt)
 997                        diffopts.output_format = stat_opt;
 998                else
 999                        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
1000                diff_tree_sha1(parent[i], sha1, "", &diffopts);
1001                diffcore_std(&diffopts);
1002                paths = intersect_paths(paths, i, num_parent);
1003
1004                if (show_log_first && i == 0) {
1005                        show_log(rev);
1006                        if (rev->verbose_header && opt->output_format)
1007                                putchar(opt->line_termination);
1008                }
1009                diff_flush(&diffopts);
1010        }
1011
1012        /* find out surviving paths */
1013        for (num_paths = 0, p = paths; p; p = p->next) {
1014                if (p->len)
1015                        num_paths++;
1016        }
1017        if (num_paths) {
1018                if (opt->output_format & (DIFF_FORMAT_RAW |
1019                                          DIFF_FORMAT_NAME |
1020                                          DIFF_FORMAT_NAME_STATUS)) {
1021                        for (p = paths; p; p = p->next) {
1022                                if (p->len)
1023                                        show_raw_diff(p, num_parent, rev);
1024                        }
1025                        needsep = 1;
1026                }
1027                else if (opt->output_format &
1028                         (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
1029                        needsep = 1;
1030                if (opt->output_format & DIFF_FORMAT_PATCH) {
1031                        if (needsep)
1032                                putchar(opt->line_termination);
1033                        for (p = paths; p; p = p->next) {
1034                                if (p->len)
1035                                        show_patch_diff(p, num_parent, dense,
1036                                                        rev);
1037                        }
1038                }
1039        }
1040
1041        /* Clean things up */
1042        while (paths) {
1043                struct combine_diff_path *tmp = paths;
1044                paths = paths->next;
1045                free(tmp);
1046        }
1047}
1048
1049void diff_tree_combined_merge(const unsigned char *sha1,
1050                             int dense, struct rev_info *rev)
1051{
1052        int num_parent;
1053        const unsigned char (*parent)[20];
1054        struct commit *commit = lookup_commit(sha1);
1055        struct commit_list *parents;
1056
1057        /* count parents */
1058        for (parents = commit->parents, num_parent = 0;
1059             parents;
1060             parents = parents->next, num_parent++)
1061                ; /* nothing */
1062
1063        parent = xmalloc(num_parent * sizeof(*parent));
1064        for (parents = commit->parents, num_parent = 0;
1065             parents;
1066             parents = parents->next, num_parent++)
1067                hashcpy((unsigned char*)(parent + num_parent),
1068                        parents->item->object.sha1);
1069        diff_tree_combined(sha1, parent, num_parent, dense, rev);
1070}