combine-diff.con commit Merge branch 'nd/maint-hide-checkout-index-from-error' (6a79be3)
   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        struct lline *next_lost;
  84        char *bol;
  85        int len;
  86        /* bit 0 up to (N-1) are on if the parent has this line (i.e.
  87         * we did not change it).
  88         * bit N is used for "interesting" lines, including context.
  89         * bit (N+1) is used for "do not show deletion before this".
  90         */
  91        unsigned long flag;
  92        unsigned long *p_lno;
  93};
  94
  95static char *grab_blob(const unsigned char *sha1, unsigned int mode, unsigned long *size)
  96{
  97        char *blob;
  98        enum object_type type;
  99
 100        if (S_ISGITLINK(mode)) {
 101                blob = xmalloc(100);
 102                *size = snprintf(blob, 100,
 103                                 "Subproject commit %s\n", sha1_to_hex(sha1));
 104        } else if (is_null_sha1(sha1)) {
 105                /* deleted blob */
 106                *size = 0;
 107                return xcalloc(1, 1);
 108        } else {
 109                blob = read_sha1_file(sha1, &type, size);
 110                if (type != OBJ_BLOB)
 111                        die("object '%s' is not a blob!", sha1_to_hex(sha1));
 112        }
 113        return blob;
 114}
 115
 116static void append_lost(struct sline *sline, int n, const char *line, int len)
 117{
 118        struct lline *lline;
 119        unsigned long this_mask = (1UL<<n);
 120        if (line[len-1] == '\n')
 121                len--;
 122
 123        /* Check to see if we can squash things */
 124        if (sline->lost_head) {
 125                lline = sline->next_lost;
 126                while (lline) {
 127                        if (lline->len == len &&
 128                            !memcmp(lline->line, line, len)) {
 129                                lline->parent_map |= this_mask;
 130                                sline->next_lost = lline->next;
 131                                return;
 132                        }
 133                        lline = lline->next;
 134                }
 135        }
 136
 137        lline = xmalloc(sizeof(*lline) + len + 1);
 138        lline->len = len;
 139        lline->next = NULL;
 140        lline->parent_map = this_mask;
 141        memcpy(lline->line, line, len);
 142        lline->line[len] = 0;
 143        *sline->lost_tail = lline;
 144        sline->lost_tail = &lline->next;
 145        sline->next_lost = NULL;
 146}
 147
 148struct combine_diff_state {
 149        unsigned int lno;
 150        int ob, on, nb, nn;
 151        unsigned long nmask;
 152        int num_parent;
 153        int n;
 154        struct sline *sline;
 155        struct sline *lost_bucket;
 156};
 157
 158static void consume_line(void *state_, char *line, unsigned long len)
 159{
 160        struct combine_diff_state *state = state_;
 161        if (5 < len && !memcmp("@@ -", line, 4)) {
 162                if (parse_hunk_header(line, len,
 163                                      &state->ob, &state->on,
 164                                      &state->nb, &state->nn))
 165                        return;
 166                state->lno = state->nb;
 167                if (state->nn == 0) {
 168                        /* @@ -X,Y +N,0 @@ removed Y lines
 169                         * that would have come *after* line N
 170                         * in the result.  Our lost buckets hang
 171                         * to the line after the removed lines,
 172                         *
 173                         * Note that this is correct even when N == 0,
 174                         * in which case the hunk removes the first
 175                         * line in the file.
 176                         */
 177                        state->lost_bucket = &state->sline[state->nb];
 178                        if (!state->nb)
 179                                state->nb = 1;
 180                } else {
 181                        state->lost_bucket = &state->sline[state->nb-1];
 182                }
 183                if (!state->sline[state->nb-1].p_lno)
 184                        state->sline[state->nb-1].p_lno =
 185                                xcalloc(state->num_parent,
 186                                        sizeof(unsigned long));
 187                state->sline[state->nb-1].p_lno[state->n] = state->ob;
 188                state->lost_bucket->next_lost = state->lost_bucket->lost_head;
 189                return;
 190        }
 191        if (!state->lost_bucket)
 192                return; /* not in any hunk yet */
 193        switch (line[0]) {
 194        case '-':
 195                append_lost(state->lost_bucket, state->n, line+1, len-1);
 196                break;
 197        case '+':
 198                state->sline[state->lno-1].flag |= state->nmask;
 199                state->lno++;
 200                break;
 201        }
 202}
 203
 204static void combine_diff(const unsigned char *parent, unsigned int mode,
 205                         mmfile_t *result_file,
 206                         struct sline *sline, unsigned int cnt, int n,
 207                         int num_parent, int result_deleted)
 208{
 209        unsigned int p_lno, lno;
 210        unsigned long nmask = (1UL << n);
 211        xpparam_t xpp;
 212        xdemitconf_t xecfg;
 213        mmfile_t parent_file;
 214        struct combine_diff_state state;
 215        unsigned long sz;
 216
 217        if (result_deleted)
 218                return; /* result deleted */
 219
 220        parent_file.ptr = grab_blob(parent, mode, &sz);
 221        parent_file.size = sz;
 222        memset(&xpp, 0, sizeof(xpp));
 223        xpp.flags = 0;
 224        memset(&xecfg, 0, sizeof(xecfg));
 225        memset(&state, 0, sizeof(state));
 226        state.nmask = nmask;
 227        state.sline = sline;
 228        state.lno = 1;
 229        state.num_parent = num_parent;
 230        state.n = n;
 231
 232        xdi_diff_outf(&parent_file, result_file, consume_line, &state,
 233                      &xpp, &xecfg);
 234        free(parent_file.ptr);
 235
 236        /* Assign line numbers for this parent.
 237         *
 238         * sline[lno].p_lno[n] records the first line number
 239         * (counting from 1) for parent N if the final hunk display
 240         * started by showing sline[lno] (possibly showing the lost
 241         * lines attached to it first).
 242         */
 243        for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
 244                struct lline *ll;
 245                sline[lno].p_lno[n] = p_lno;
 246
 247                /* How many lines would this sline advance the p_lno? */
 248                ll = sline[lno].lost_head;
 249                while (ll) {
 250                        if (ll->parent_map & nmask)
 251                                p_lno++; /* '-' means parent had it */
 252                        ll = ll->next;
 253                }
 254                if (lno < cnt && !(sline[lno].flag & nmask))
 255                        p_lno++; /* no '+' means parent had it */
 256        }
 257        sline[lno].p_lno[n] = p_lno; /* trailer */
 258}
 259
 260static unsigned long context = 3;
 261static char combine_marker = '@';
 262
 263static int interesting(struct sline *sline, unsigned long all_mask)
 264{
 265        /* If some parents lost lines here, or if we have added to
 266         * some parent, it is interesting.
 267         */
 268        return ((sline->flag & all_mask) || sline->lost_head);
 269}
 270
 271static unsigned long adjust_hunk_tail(struct sline *sline,
 272                                      unsigned long all_mask,
 273                                      unsigned long hunk_begin,
 274                                      unsigned long i)
 275{
 276        /* i points at the first uninteresting line.  If the last line
 277         * of the hunk was interesting only because it has some
 278         * deletion, then it is not all that interesting for the
 279         * purpose of giving trailing context lines.  This is because
 280         * we output '-' line and then unmodified sline[i-1] itself in
 281         * that case which gives us one extra context line.
 282         */
 283        if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
 284                i--;
 285        return i;
 286}
 287
 288static unsigned long find_next(struct sline *sline,
 289                               unsigned long mark,
 290                               unsigned long i,
 291                               unsigned long cnt,
 292                               int look_for_uninteresting)
 293{
 294        /* We have examined up to i-1 and are about to look at i.
 295         * Find next interesting or uninteresting line.  Here,
 296         * "interesting" does not mean interesting(), but marked by
 297         * the give_context() function below (i.e. it includes context
 298         * lines that are not interesting to interesting() function
 299         * that are surrounded by interesting() ones.
 300         */
 301        while (i <= cnt)
 302                if (look_for_uninteresting
 303                    ? !(sline[i].flag & mark)
 304                    : (sline[i].flag & mark))
 305                        return i;
 306                else
 307                        i++;
 308        return i;
 309}
 310
 311static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 312{
 313        unsigned long all_mask = (1UL<<num_parent) - 1;
 314        unsigned long mark = (1UL<<num_parent);
 315        unsigned long no_pre_delete = (2UL<<num_parent);
 316        unsigned long i;
 317
 318        /* Two groups of interesting lines may have a short gap of
 319         * uninteresting lines.  Connect such groups to give them a
 320         * bit of context.
 321         *
 322         * We first start from what the interesting() function says,
 323         * and mark them with "mark", and paint context lines with the
 324         * mark.  So interesting() would still say false for such context
 325         * lines but they are treated as "interesting" in the end.
 326         */
 327        i = find_next(sline, mark, 0, cnt, 0);
 328        if (cnt < i)
 329                return 0;
 330
 331        while (i <= cnt) {
 332                unsigned long j = (context < i) ? (i - context) : 0;
 333                unsigned long k;
 334
 335                /* Paint a few lines before the first interesting line. */
 336                while (j < i)
 337                        sline[j++].flag |= mark | no_pre_delete;
 338
 339        again:
 340                /* we know up to i is to be included.  where does the
 341                 * next uninteresting one start?
 342                 */
 343                j = find_next(sline, mark, i, cnt, 1);
 344                if (cnt < j)
 345                        break; /* the rest are all interesting */
 346
 347                /* lookahead context lines */
 348                k = find_next(sline, mark, j, cnt, 0);
 349                j = adjust_hunk_tail(sline, all_mask, i, j);
 350
 351                if (k < j + context) {
 352                        /* k is interesting and [j,k) are not, but
 353                         * paint them interesting because the gap is small.
 354                         */
 355                        while (j < k)
 356                                sline[j++].flag |= mark;
 357                        i = k;
 358                        goto again;
 359                }
 360
 361                /* j is the first uninteresting line and there is
 362                 * no overlap beyond it within context lines.  Paint
 363                 * the trailing edge a bit.
 364                 */
 365                i = k;
 366                k = (j + context < cnt+1) ? j + context : cnt+1;
 367                while (j < k)
 368                        sline[j++].flag |= mark;
 369        }
 370        return 1;
 371}
 372
 373static int make_hunks(struct sline *sline, unsigned long cnt,
 374                       int num_parent, int dense)
 375{
 376        unsigned long all_mask = (1UL<<num_parent) - 1;
 377        unsigned long mark = (1UL<<num_parent);
 378        unsigned long i;
 379        int has_interesting = 0;
 380
 381        for (i = 0; i <= cnt; i++) {
 382                if (interesting(&sline[i], all_mask))
 383                        sline[i].flag |= mark;
 384                else
 385                        sline[i].flag &= ~mark;
 386        }
 387        if (!dense)
 388                return give_context(sline, cnt, num_parent);
 389
 390        /* Look at each hunk, and if we have changes from only one
 391         * parent, or the changes are the same from all but one
 392         * parent, mark that uninteresting.
 393         */
 394        i = 0;
 395        while (i <= cnt) {
 396                unsigned long j, hunk_begin, hunk_end;
 397                unsigned long same_diff;
 398                while (i <= cnt && !(sline[i].flag & mark))
 399                        i++;
 400                if (cnt < i)
 401                        break; /* No more interesting hunks */
 402                hunk_begin = i;
 403                for (j = i + 1; j <= cnt; j++) {
 404                        if (!(sline[j].flag & mark)) {
 405                                /* Look beyond the end to see if there
 406                                 * is an interesting line after this
 407                                 * hunk within context span.
 408                                 */
 409                                unsigned long la; /* lookahead */
 410                                int contin = 0;
 411                                la = adjust_hunk_tail(sline, all_mask,
 412                                                     hunk_begin, j);
 413                                la = (la + context < cnt + 1) ?
 414                                        (la + context) : cnt + 1;
 415                                while (j <= --la) {
 416                                        if (sline[la].flag & mark) {
 417                                                contin = 1;
 418                                                break;
 419                                        }
 420                                }
 421                                if (!contin)
 422                                        break;
 423                                j = la;
 424                        }
 425                }
 426                hunk_end = j;
 427
 428                /* [i..hunk_end) are interesting.  Now is it really
 429                 * interesting?  We check if there are only two versions
 430                 * and the result matches one of them.  That is, we look
 431                 * at:
 432                 *   (+) line, which records lines added to which parents;
 433                 *       this line appears in the result.
 434                 *   (-) line, which records from what parents the line
 435                 *       was removed; this line does not appear in the result.
 436                 * then check the set of parents the result has difference
 437                 * from, from all lines.  If there are lines that has
 438                 * different set of parents that the result has differences
 439                 * from, that means we have more than two versions.
 440                 *
 441                 * Even when we have only two versions, if the result does
 442                 * not match any of the parents, the it should be considered
 443                 * interesting.  In such a case, we would have all '+' line.
 444                 * After passing the above "two versions" test, that would
 445                 * appear as "the same set of parents" to be "all parents".
 446                 */
 447                same_diff = 0;
 448                has_interesting = 0;
 449                for (j = i; j < hunk_end && !has_interesting; j++) {
 450                        unsigned long this_diff = sline[j].flag & all_mask;
 451                        struct lline *ll = sline[j].lost_head;
 452                        if (this_diff) {
 453                                /* This has some changes.  Is it the
 454                                 * same as others?
 455                                 */
 456                                if (!same_diff)
 457                                        same_diff = this_diff;
 458                                else if (same_diff != this_diff) {
 459                                        has_interesting = 1;
 460                                        break;
 461                                }
 462                        }
 463                        while (ll && !has_interesting) {
 464                                /* Lost this line from these parents;
 465                                 * who are they?  Are they the same?
 466                                 */
 467                                this_diff = ll->parent_map;
 468                                if (!same_diff)
 469                                        same_diff = this_diff;
 470                                else if (same_diff != this_diff) {
 471                                        has_interesting = 1;
 472                                }
 473                                ll = ll->next;
 474                        }
 475                }
 476
 477                if (!has_interesting && same_diff != all_mask) {
 478                        /* This hunk is not that interesting after all */
 479                        for (j = hunk_begin; j < hunk_end; j++)
 480                                sline[j].flag &= ~mark;
 481                }
 482                i = hunk_end;
 483        }
 484
 485        has_interesting = give_context(sline, cnt, num_parent);
 486        return has_interesting;
 487}
 488
 489static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
 490{
 491        l0 = sline[l0].p_lno[n];
 492        l1 = sline[l1].p_lno[n];
 493        printf(" -%lu,%lu", l0, l1-l0-null_context);
 494}
 495
 496static int hunk_comment_line(const char *bol)
 497{
 498        int ch;
 499
 500        if (!bol)
 501                return 0;
 502        ch = *bol & 0xff;
 503        return (isalpha(ch) || ch == '_' || ch == '$');
 504}
 505
 506static void show_line_to_eol(const char *line, int len, const char *reset)
 507{
 508        int saw_cr_at_eol = 0;
 509        if (len < 0)
 510                len = strlen(line);
 511        saw_cr_at_eol = (len && line[len-1] == '\r');
 512
 513        printf("%.*s%s%s\n", len - saw_cr_at_eol, line,
 514               reset,
 515               saw_cr_at_eol ? "\r" : "");
 516}
 517
 518static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 519                       int use_color, int result_deleted)
 520{
 521        unsigned long mark = (1UL<<num_parent);
 522        unsigned long no_pre_delete = (2UL<<num_parent);
 523        int i;
 524        unsigned long lno = 0;
 525        const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
 526        const char *c_func = diff_get_color(use_color, DIFF_FUNCINFO);
 527        const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
 528        const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
 529        const char *c_plain = diff_get_color(use_color, DIFF_PLAIN);
 530        const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 531
 532        if (result_deleted)
 533                return; /* result deleted */
 534
 535        while (1) {
 536                unsigned long hunk_end;
 537                unsigned long rlines;
 538                const char *hunk_comment = NULL;
 539                unsigned long null_context = 0;
 540
 541                while (lno <= cnt && !(sline[lno].flag & mark)) {
 542                        if (hunk_comment_line(sline[lno].bol))
 543                                hunk_comment = sline[lno].bol;
 544                        lno++;
 545                }
 546                if (cnt < lno)
 547                        break;
 548                else {
 549                        for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
 550                                if (!(sline[hunk_end].flag & mark))
 551                                        break;
 552                }
 553                rlines = hunk_end - lno;
 554                if (cnt < hunk_end)
 555                        rlines--; /* pointing at the last delete hunk */
 556
 557                if (!context) {
 558                        /*
 559                         * Even when running with --unified=0, all
 560                         * lines in the hunk needs to be processed in
 561                         * the loop below in order to show the
 562                         * deletion recorded in lost_head.  However,
 563                         * we do not want to show the resulting line
 564                         * with all blank context markers in such a
 565                         * case.  Compensate.
 566                         */
 567                        unsigned long j;
 568                        for (j = lno; j < hunk_end; j++)
 569                                if (!(sline[j].flag & (mark-1)))
 570                                        null_context++;
 571                        rlines -= null_context;
 572                }
 573
 574                fputs(c_frag, stdout);
 575                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 576                for (i = 0; i < num_parent; i++)
 577                        show_parent_lno(sline, lno, hunk_end, i, null_context);
 578                printf(" +%lu,%lu ", lno+1, rlines);
 579                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 580
 581                if (hunk_comment) {
 582                        int comment_end = 0;
 583                        for (i = 0; i < 40; i++) {
 584                                int ch = hunk_comment[i] & 0xff;
 585                                if (!ch || ch == '\n')
 586                                        break;
 587                                if (!isspace(ch))
 588                                    comment_end = i;
 589                        }
 590                        if (comment_end)
 591                                printf("%s%s %s%s", c_reset,
 592                                                    c_plain, c_reset,
 593                                                    c_func);
 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                        struct sline *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        int result_deleted = 0;
 690        char *result, *cp;
 691        struct sline *sline; /* survived lines */
 692        int mode_differs = 0;
 693        int i, show_hunks;
 694        int working_tree_file = is_null_sha1(elem->sha1);
 695        int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
 696        const char *a_prefix, *b_prefix;
 697        mmfile_t result_file;
 698
 699        context = opt->context;
 700        a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
 701        b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
 702
 703        /* Read the result of merge first */
 704        if (!working_tree_file)
 705                result = grab_blob(elem->sha1, elem->mode, &result_size);
 706        else {
 707                /* Used by diff-tree to read from the working tree */
 708                struct stat st;
 709                int fd = -1;
 710
 711                if (lstat(elem->path, &st) < 0)
 712                        goto deleted_file;
 713
 714                if (S_ISLNK(st.st_mode)) {
 715                        struct strbuf buf = STRBUF_INIT;
 716
 717                        if (strbuf_readlink(&buf, elem->path, st.st_size) < 0) {
 718                                error("readlink(%s): %s", elem->path,
 719                                      strerror(errno));
 720                                return;
 721                        }
 722                        result_size = buf.len;
 723                        result = strbuf_detach(&buf, NULL);
 724                        elem->mode = canon_mode(st.st_mode);
 725                } else if (S_ISDIR(st.st_mode)) {
 726                        unsigned char sha1[20];
 727                        if (resolve_gitlink_ref(elem->path, "HEAD", sha1) < 0)
 728                                result = grab_blob(elem->sha1, elem->mode, &result_size);
 729                        else
 730                                result = grab_blob(sha1, elem->mode, &result_size);
 731                } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
 732                        size_t len = xsize_t(st.st_size);
 733                        ssize_t done;
 734                        int is_file, i;
 735
 736                        elem->mode = canon_mode(st.st_mode);
 737                        /* if symlinks don't work, assume symlink if all parents
 738                         * are symlinks
 739                         */
 740                        is_file = has_symlinks;
 741                        for (i = 0; !is_file && i < num_parent; i++)
 742                                is_file = !S_ISLNK(elem->parent[i].mode);
 743                        if (!is_file)
 744                                elem->mode = canon_mode(S_IFLNK);
 745
 746                        result_size = len;
 747                        result = xmalloc(len + 1);
 748
 749                        done = read_in_full(fd, result, len);
 750                        if (done < 0)
 751                                die_errno("read error '%s'", elem->path);
 752                        else if (done < len)
 753                                die("early EOF '%s'", elem->path);
 754
 755                        result[len] = 0;
 756
 757                        /* If not a fake symlink, apply filters, e.g. autocrlf */
 758                        if (is_file) {
 759                                struct strbuf buf = STRBUF_INIT;
 760
 761                                if (convert_to_git(elem->path, result, len, &buf, safe_crlf)) {
 762                                        free(result);
 763                                        result = strbuf_detach(&buf, &len);
 764                                        result_size = len;
 765                                }
 766                        }
 767                }
 768                else {
 769                deleted_file:
 770                        result_deleted = 1;
 771                        result_size = 0;
 772                        elem->mode = 0;
 773                        result = xcalloc(1, 1);
 774                }
 775
 776                if (0 <= fd)
 777                        close(fd);
 778        }
 779
 780        for (cnt = 0, cp = result; cp < result + result_size; cp++) {
 781                if (*cp == '\n')
 782                        cnt++;
 783        }
 784        if (result_size && result[result_size-1] != '\n')
 785                cnt++; /* incomplete line */
 786
 787        sline = xcalloc(cnt+2, sizeof(*sline));
 788        sline[0].bol = result;
 789        for (lno = 0; lno <= cnt + 1; lno++) {
 790                sline[lno].lost_tail = &sline[lno].lost_head;
 791                sline[lno].flag = 0;
 792        }
 793        for (lno = 0, cp = result; cp < result + result_size; cp++) {
 794                if (*cp == '\n') {
 795                        sline[lno].len = cp - sline[lno].bol;
 796                        lno++;
 797                        if (lno < cnt)
 798                                sline[lno].bol = cp + 1;
 799                }
 800        }
 801        if (result_size && result[result_size-1] != '\n')
 802                sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
 803
 804        result_file.ptr = result;
 805        result_file.size = result_size;
 806
 807        /* Even p_lno[cnt+1] is valid -- that is for the end line number
 808         * for deletion hunk at the end.
 809         */
 810        sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
 811        for (lno = 0; lno <= cnt; lno++)
 812                sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
 813
 814        for (i = 0; i < num_parent; i++) {
 815                int j;
 816                for (j = 0; j < i; j++) {
 817                        if (!hashcmp(elem->parent[i].sha1,
 818                                     elem->parent[j].sha1)) {
 819                                reuse_combine_diff(sline, cnt, i, j);
 820                                break;
 821                        }
 822                }
 823                if (i <= j)
 824                        combine_diff(elem->parent[i].sha1,
 825                                     elem->parent[i].mode,
 826                                     &result_file, sline,
 827                                     cnt, i, num_parent, result_deleted);
 828                if (elem->parent[i].mode != elem->mode)
 829                        mode_differs = 1;
 830        }
 831
 832        show_hunks = make_hunks(sline, cnt, num_parent, dense);
 833
 834        if (show_hunks || mode_differs || working_tree_file) {
 835                const char *abb;
 836                int use_color = DIFF_OPT_TST(opt, COLOR_DIFF);
 837                const char *c_meta = diff_get_color(use_color, DIFF_METAINFO);
 838                const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 839                int added = 0;
 840                int deleted = 0;
 841
 842                if (rev->loginfo && !rev->no_commit_id)
 843                        show_log(rev);
 844                dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
 845                                 "", elem->path, c_meta, c_reset);
 846                printf("%sindex ", c_meta);
 847                for (i = 0; i < num_parent; i++) {
 848                        abb = find_unique_abbrev(elem->parent[i].sha1,
 849                                                 abbrev);
 850                        printf("%s%s", i ? "," : "", abb);
 851                }
 852                abb = find_unique_abbrev(elem->sha1, abbrev);
 853                printf("..%s%s\n", abb, c_reset);
 854
 855                if (mode_differs) {
 856                        deleted = !elem->mode;
 857
 858                        /* We say it was added if nobody had it */
 859                        added = !deleted;
 860                        for (i = 0; added && i < num_parent; i++)
 861                                if (elem->parent[i].status !=
 862                                    DIFF_STATUS_ADDED)
 863                                        added = 0;
 864                        if (added)
 865                                printf("%snew file mode %06o",
 866                                       c_meta, elem->mode);
 867                        else {
 868                                if (deleted)
 869                                        printf("%sdeleted file ", c_meta);
 870                                printf("mode ");
 871                                for (i = 0; i < num_parent; i++) {
 872                                        printf("%s%06o", i ? "," : "",
 873                                               elem->parent[i].mode);
 874                                }
 875                                if (elem->mode)
 876                                        printf("..%06o", elem->mode);
 877                        }
 878                        printf("%s\n", c_reset);
 879                }
 880                if (added)
 881                        dump_quoted_path("--- ", "", "/dev/null",
 882                                         c_meta, c_reset);
 883                else
 884                        dump_quoted_path("--- ", a_prefix, elem->path,
 885                                         c_meta, c_reset);
 886                if (deleted)
 887                        dump_quoted_path("+++ ", "", "/dev/null",
 888                                         c_meta, c_reset);
 889                else
 890                        dump_quoted_path("+++ ", b_prefix, elem->path,
 891                                         c_meta, c_reset);
 892                dump_sline(sline, cnt, num_parent,
 893                           DIFF_OPT_TST(opt, COLOR_DIFF), result_deleted);
 894        }
 895        free(result);
 896
 897        for (lno = 0; lno < cnt; lno++) {
 898                if (sline[lno].lost_head) {
 899                        struct lline *ll = sline[lno].lost_head;
 900                        while (ll) {
 901                                struct lline *tmp = ll;
 902                                ll = ll->next;
 903                                free(tmp);
 904                        }
 905                }
 906        }
 907        free(sline[0].p_lno);
 908        free(sline);
 909}
 910
 911#define COLONS "::::::::::::::::::::::::::::::::"
 912
 913static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
 914{
 915        struct diff_options *opt = &rev->diffopt;
 916        int i, offset;
 917        const char *prefix;
 918        int line_termination, inter_name_termination;
 919
 920        line_termination = opt->line_termination;
 921        inter_name_termination = '\t';
 922        if (!line_termination)
 923                inter_name_termination = 0;
 924
 925        if (rev->loginfo && !rev->no_commit_id)
 926                show_log(rev);
 927
 928        if (opt->output_format & DIFF_FORMAT_RAW) {
 929                offset = strlen(COLONS) - num_parent;
 930                if (offset < 0)
 931                        offset = 0;
 932                prefix = COLONS + offset;
 933
 934                /* Show the modes */
 935                for (i = 0; i < num_parent; i++) {
 936                        printf("%s%06o", prefix, p->parent[i].mode);
 937                        prefix = " ";
 938                }
 939                printf("%s%06o", prefix, p->mode);
 940
 941                /* Show sha1's */
 942                for (i = 0; i < num_parent; i++)
 943                        printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
 944                                                         opt->abbrev));
 945                printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
 946        }
 947
 948        if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
 949                for (i = 0; i < num_parent; i++)
 950                        putchar(p->parent[i].status);
 951                putchar(inter_name_termination);
 952        }
 953
 954        write_name_quoted(p->path, stdout, line_termination);
 955}
 956
 957void show_combined_diff(struct combine_diff_path *p,
 958                       int num_parent,
 959                       int dense,
 960                       struct rev_info *rev)
 961{
 962        struct diff_options *opt = &rev->diffopt;
 963        if (!p->len)
 964                return;
 965        if (opt->output_format & (DIFF_FORMAT_RAW |
 966                                  DIFF_FORMAT_NAME |
 967                                  DIFF_FORMAT_NAME_STATUS))
 968                show_raw_diff(p, num_parent, rev);
 969        else if (opt->output_format & DIFF_FORMAT_PATCH)
 970                show_patch_diff(p, num_parent, dense, rev);
 971}
 972
 973void diff_tree_combined(const unsigned char *sha1,
 974                        const unsigned char parent[][20],
 975                        int num_parent,
 976                        int dense,
 977                        struct rev_info *rev)
 978{
 979        struct diff_options *opt = &rev->diffopt;
 980        struct diff_options diffopts;
 981        struct combine_diff_path *p, *paths = NULL;
 982        int i, num_paths, needsep, show_log_first;
 983
 984        diffopts = *opt;
 985        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
 986        DIFF_OPT_SET(&diffopts, RECURSIVE);
 987        DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
 988
 989        show_log_first = !!rev->loginfo && !rev->no_commit_id;
 990        needsep = 0;
 991        /* find set of paths that everybody touches */
 992        for (i = 0; i < num_parent; i++) {
 993                /* show stat against the first parent even
 994                 * when doing combined diff.
 995                 */
 996                int stat_opt = (opt->output_format &
 997                                (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
 998                if (i == 0 && stat_opt)
 999                        diffopts.output_format = stat_opt;
1000                else
1001                        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
1002                diff_tree_sha1(parent[i], sha1, "", &diffopts);
1003                diffcore_std(&diffopts);
1004                paths = intersect_paths(paths, i, num_parent);
1005
1006                if (show_log_first && i == 0) {
1007                        show_log(rev);
1008                        if (rev->verbose_header && opt->output_format)
1009                                putchar(opt->line_termination);
1010                }
1011                diff_flush(&diffopts);
1012        }
1013
1014        /* find out surviving paths */
1015        for (num_paths = 0, p = paths; p; p = p->next) {
1016                if (p->len)
1017                        num_paths++;
1018        }
1019        if (num_paths) {
1020                if (opt->output_format & (DIFF_FORMAT_RAW |
1021                                          DIFF_FORMAT_NAME |
1022                                          DIFF_FORMAT_NAME_STATUS)) {
1023                        for (p = paths; p; p = p->next) {
1024                                if (p->len)
1025                                        show_raw_diff(p, num_parent, rev);
1026                        }
1027                        needsep = 1;
1028                }
1029                else if (opt->output_format &
1030                         (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
1031                        needsep = 1;
1032                if (opt->output_format & DIFF_FORMAT_PATCH) {
1033                        if (needsep)
1034                                putchar(opt->line_termination);
1035                        for (p = paths; p; p = p->next) {
1036                                if (p->len)
1037                                        show_patch_diff(p, num_parent, dense,
1038                                                        rev);
1039                        }
1040                }
1041        }
1042
1043        /* Clean things up */
1044        while (paths) {
1045                struct combine_diff_path *tmp = paths;
1046                paths = paths->next;
1047                free(tmp);
1048        }
1049}
1050
1051void diff_tree_combined_merge(const unsigned char *sha1,
1052                             int dense, struct rev_info *rev)
1053{
1054        int num_parent;
1055        const unsigned char (*parent)[20];
1056        struct commit *commit = lookup_commit(sha1);
1057        struct commit_list *parents;
1058
1059        /* count parents */
1060        for (parents = commit->parents, num_parent = 0;
1061             parents;
1062             parents = parents->next, num_parent++)
1063                ; /* nothing */
1064
1065        parent = xmalloc(num_parent * sizeof(*parent));
1066        for (parents = commit->parents, num_parent = 0;
1067             parents;
1068             parents = parents->next, num_parent++)
1069                hashcpy((unsigned char *)(parent + num_parent),
1070                        parents->item->object.sha1);
1071        diff_tree_combined(sha1, parent, num_parent, dense, rev);
1072}