combine-diff.con commit git-add --intent-to-add (-N) (3942581)
   1#include "cache.h"
   2#include "commit.h"
   3#include "blob.h"
   4#include "diff.h"
   5#include "diffcore.h"
   6#include "quote.h"
   7#include "xdiff-interface.h"
   8#include "log-tree.h"
   9
  10static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
  11{
  12        struct diff_queue_struct *q = &diff_queued_diff;
  13        struct combine_diff_path *p;
  14        int i;
  15
  16        if (!n) {
  17                struct combine_diff_path *list = NULL, **tail = &list;
  18                for (i = 0; i < q->nr; i++) {
  19                        int len;
  20                        const char *path;
  21                        if (diff_unmodified_pair(q->queue[i]))
  22                                continue;
  23                        path = q->queue[i]->two->path;
  24                        len = strlen(path);
  25                        p = xmalloc(combine_diff_path_size(num_parent, len));
  26                        p->path = (char*) &(p->parent[num_parent]);
  27                        memcpy(p->path, path, len);
  28                        p->path[len] = 0;
  29                        p->len = len;
  30                        p->next = NULL;
  31                        memset(p->parent, 0,
  32                               sizeof(p->parent[0]) * num_parent);
  33
  34                        hashcpy(p->sha1, q->queue[i]->two->sha1);
  35                        p->mode = q->queue[i]->two->mode;
  36                        hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
  37                        p->parent[n].mode = q->queue[i]->one->mode;
  38                        p->parent[n].status = q->queue[i]->status;
  39                        *tail = p;
  40                        tail = &p->next;
  41                }
  42                return list;
  43        }
  44
  45        for (p = curr; p; p = p->next) {
  46                int found = 0;
  47                if (!p->len)
  48                        continue;
  49                for (i = 0; i < q->nr; i++) {
  50                        const char *path;
  51                        int len;
  52
  53                        if (diff_unmodified_pair(q->queue[i]))
  54                                continue;
  55                        path = q->queue[i]->two->path;
  56                        len = strlen(path);
  57                        if (len == p->len && !memcmp(path, p->path, len)) {
  58                                found = 1;
  59                                hashcpy(p->parent[n].sha1, q->queue[i]->one->sha1);
  60                                p->parent[n].mode = q->queue[i]->one->mode;
  61                                p->parent[n].status = q->queue[i]->status;
  62                                break;
  63                        }
  64                }
  65                if (!found)
  66                        p->len = 0;
  67        }
  68        return curr;
  69}
  70
  71/* Lines lost from parent */
  72struct lline {
  73        struct lline *next;
  74        int len;
  75        unsigned long parent_map;
  76        char line[FLEX_ARRAY];
  77};
  78
  79/* Lines surviving in the merge result */
  80struct sline {
  81        struct lline *lost_head, **lost_tail;
  82        char *bol;
  83        int len;
  84        /* bit 0 up to (N-1) are on if the parent has this line (i.e.
  85         * we did not change it).
  86         * bit N is used for "interesting" lines, including context.
  87         * bit (N+1) is used for "do not show deletion before this".
  88         */
  89        unsigned long flag;
  90        unsigned long *p_lno;
  91};
  92
  93static char *grab_blob(const unsigned char *sha1, unsigned long *size)
  94{
  95        char *blob;
  96        enum object_type type;
  97        if (is_null_sha1(sha1)) {
  98                /* deleted blob */
  99                *size = 0;
 100                return xcalloc(1, 1);
 101        }
 102        blob = read_sha1_file(sha1, &type, size);
 103        if (type != OBJ_BLOB)
 104                die("object '%s' is not a blob!", sha1_to_hex(sha1));
 105        return blob;
 106}
 107
 108static void append_lost(struct sline *sline, int n, const char *line, int len)
 109{
 110        struct lline *lline;
 111        unsigned long this_mask = (1UL<<n);
 112        if (line[len-1] == '\n')
 113                len--;
 114
 115        /* Check to see if we can squash things */
 116        if (sline->lost_head) {
 117                struct lline *last_one = NULL;
 118                /* We cannot squash it with earlier one */
 119                for (lline = sline->lost_head;
 120                     lline;
 121                     lline = lline->next)
 122                        if (lline->parent_map & this_mask)
 123                                last_one = lline;
 124                lline = last_one ? last_one->next : sline->lost_head;
 125                while (lline) {
 126                        if (lline->len == len &&
 127                            !memcmp(lline->line, line, len)) {
 128                                lline->parent_map |= this_mask;
 129                                return;
 130                        }
 131                        lline = lline->next;
 132                }
 133        }
 134
 135        lline = xmalloc(sizeof(*lline) + len + 1);
 136        lline->len = len;
 137        lline->next = NULL;
 138        lline->parent_map = this_mask;
 139        memcpy(lline->line, line, len);
 140        lline->line[len] = 0;
 141        *sline->lost_tail = lline;
 142        sline->lost_tail = &lline->next;
 143}
 144
 145struct combine_diff_state {
 146        unsigned int lno;
 147        int ob, on, nb, nn;
 148        unsigned long nmask;
 149        int num_parent;
 150        int n;
 151        struct sline *sline;
 152        struct sline *lost_bucket;
 153};
 154
 155static void consume_line(void *state_, char *line, unsigned long len)
 156{
 157        struct combine_diff_state *state = state_;
 158        if (5 < len && !memcmp("@@ -", line, 4)) {
 159                if (parse_hunk_header(line, len,
 160                                      &state->ob, &state->on,
 161                                      &state->nb, &state->nn))
 162                        return;
 163                state->lno = state->nb;
 164                if (!state->nb)
 165                        /* @@ -1,2 +0,0 @@ to remove the
 166                         * first two lines...
 167                         */
 168                        state->nb = 1;
 169                if (state->nn == 0)
 170                        /* @@ -X,Y +N,0 @@ removed Y lines
 171                         * that would have come *after* line N
 172                         * in the result.  Our lost buckets hang
 173                         * to the line after the removed lines,
 174                         */
 175                        state->lost_bucket = &state->sline[state->nb];
 176                else
 177                        state->lost_bucket = &state->sline[state->nb-1];
 178                if (!state->sline[state->nb-1].p_lno)
 179                        state->sline[state->nb-1].p_lno =
 180                                xcalloc(state->num_parent,
 181                                        sizeof(unsigned long));
 182                state->sline[state->nb-1].p_lno[state->n] = state->ob;
 183                return;
 184        }
 185        if (!state->lost_bucket)
 186                return; /* not in any hunk yet */
 187        switch (line[0]) {
 188        case '-':
 189                append_lost(state->lost_bucket, state->n, line+1, len-1);
 190                break;
 191        case '+':
 192                state->sline[state->lno-1].flag |= state->nmask;
 193                state->lno++;
 194                break;
 195        }
 196}
 197
 198static void combine_diff(const unsigned char *parent, mmfile_t *result_file,
 199                         struct sline *sline, unsigned int cnt, int n,
 200                         int num_parent)
 201{
 202        unsigned int p_lno, lno;
 203        unsigned long nmask = (1UL << n);
 204        xpparam_t xpp;
 205        xdemitconf_t xecfg;
 206        mmfile_t parent_file;
 207        xdemitcb_t ecb;
 208        struct combine_diff_state state;
 209        unsigned long sz;
 210
 211        if (!cnt)
 212                return; /* result deleted */
 213
 214        parent_file.ptr = grab_blob(parent, &sz);
 215        parent_file.size = sz;
 216        xpp.flags = XDF_NEED_MINIMAL;
 217        memset(&xecfg, 0, sizeof(xecfg));
 218        memset(&state, 0, sizeof(state));
 219        state.nmask = nmask;
 220        state.sline = sline;
 221        state.lno = 1;
 222        state.num_parent = num_parent;
 223        state.n = n;
 224
 225        xdi_diff_outf(&parent_file, result_file, consume_line, &state,
 226                      &xpp, &xecfg, &ecb);
 227        free(parent_file.ptr);
 228
 229        /* Assign line numbers for this parent.
 230         *
 231         * sline[lno].p_lno[n] records the first line number
 232         * (counting from 1) for parent N if the final hunk display
 233         * started by showing sline[lno] (possibly showing the lost
 234         * lines attached to it first).
 235         */
 236        for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
 237                struct lline *ll;
 238                sline[lno].p_lno[n] = p_lno;
 239
 240                /* How many lines would this sline advance the p_lno? */
 241                ll = sline[lno].lost_head;
 242                while (ll) {
 243                        if (ll->parent_map & nmask)
 244                                p_lno++; /* '-' means parent had it */
 245                        ll = ll->next;
 246                }
 247                if (lno < cnt && !(sline[lno].flag & nmask))
 248                        p_lno++; /* no '+' means parent had it */
 249        }
 250        sline[lno].p_lno[n] = p_lno; /* trailer */
 251}
 252
 253static unsigned long context = 3;
 254static char combine_marker = '@';
 255
 256static int interesting(struct sline *sline, unsigned long all_mask)
 257{
 258        /* If some parents lost lines here, or if we have added to
 259         * some parent, it is interesting.
 260         */
 261        return ((sline->flag & all_mask) || sline->lost_head);
 262}
 263
 264static unsigned long adjust_hunk_tail(struct sline *sline,
 265                                      unsigned long all_mask,
 266                                      unsigned long hunk_begin,
 267                                      unsigned long i)
 268{
 269        /* i points at the first uninteresting line.  If the last line
 270         * of the hunk was interesting only because it has some
 271         * deletion, then it is not all that interesting for the
 272         * purpose of giving trailing context lines.  This is because
 273         * we output '-' line and then unmodified sline[i-1] itself in
 274         * that case which gives us one extra context line.
 275         */
 276        if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
 277                i--;
 278        return i;
 279}
 280
 281static unsigned long find_next(struct sline *sline,
 282                               unsigned long mark,
 283                               unsigned long i,
 284                               unsigned long cnt,
 285                               int look_for_uninteresting)
 286{
 287        /* We have examined up to i-1 and are about to look at i.
 288         * Find next interesting or uninteresting line.  Here,
 289         * "interesting" does not mean interesting(), but marked by
 290         * the give_context() function below (i.e. it includes context
 291         * lines that are not interesting to interesting() function
 292         * that are surrounded by interesting() ones.
 293         */
 294        while (i <= cnt)
 295                if (look_for_uninteresting
 296                    ? !(sline[i].flag & mark)
 297                    : (sline[i].flag & mark))
 298                        return i;
 299                else
 300                        i++;
 301        return i;
 302}
 303
 304static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 305{
 306        unsigned long all_mask = (1UL<<num_parent) - 1;
 307        unsigned long mark = (1UL<<num_parent);
 308        unsigned long no_pre_delete = (2UL<<num_parent);
 309        unsigned long i;
 310
 311        /* Two groups of interesting lines may have a short gap of
 312         * uninteresting lines.  Connect such groups to give them a
 313         * bit of context.
 314         *
 315         * We first start from what the interesting() function says,
 316         * and mark them with "mark", and paint context lines with the
 317         * mark.  So interesting() would still say false for such context
 318         * lines but they are treated as "interesting" in the end.
 319         */
 320        i = find_next(sline, mark, 0, cnt, 0);
 321        if (cnt < i)
 322                return 0;
 323
 324        while (i <= cnt) {
 325                unsigned long j = (context < i) ? (i - context) : 0;
 326                unsigned long k;
 327
 328                /* Paint a few lines before the first interesting line. */
 329                while (j < i)
 330                        sline[j++].flag |= mark | no_pre_delete;
 331
 332        again:
 333                /* we know up to i is to be included.  where does the
 334                 * next uninteresting one start?
 335                 */
 336                j = find_next(sline, mark, i, cnt, 1);
 337                if (cnt < j)
 338                        break; /* the rest are all interesting */
 339
 340                /* lookahead context lines */
 341                k = find_next(sline, mark, j, cnt, 0);
 342                j = adjust_hunk_tail(sline, all_mask, i, j);
 343
 344                if (k < j + context) {
 345                        /* k is interesting and [j,k) are not, but
 346                         * paint them interesting because the gap is small.
 347                         */
 348                        while (j < k)
 349                                sline[j++].flag |= mark;
 350                        i = k;
 351                        goto again;
 352                }
 353
 354                /* j is the first uninteresting line and there is
 355                 * no overlap beyond it within context lines.  Paint
 356                 * the trailing edge a bit.
 357                 */
 358                i = k;
 359                k = (j + context < cnt+1) ? j + context : cnt+1;
 360                while (j < k)
 361                        sline[j++].flag |= mark;
 362        }
 363        return 1;
 364}
 365
 366static int make_hunks(struct sline *sline, unsigned long cnt,
 367                       int num_parent, int dense)
 368{
 369        unsigned long all_mask = (1UL<<num_parent) - 1;
 370        unsigned long mark = (1UL<<num_parent);
 371        unsigned long i;
 372        int has_interesting = 0;
 373
 374        for (i = 0; i <= cnt; i++) {
 375                if (interesting(&sline[i], all_mask))
 376                        sline[i].flag |= mark;
 377                else
 378                        sline[i].flag &= ~mark;
 379        }
 380        if (!dense)
 381                return give_context(sline, cnt, num_parent);
 382
 383        /* Look at each hunk, and if we have changes from only one
 384         * parent, or the changes are the same from all but one
 385         * parent, mark that uninteresting.
 386         */
 387        i = 0;
 388        while (i <= cnt) {
 389                unsigned long j, hunk_begin, hunk_end;
 390                unsigned long same_diff;
 391                while (i <= cnt && !(sline[i].flag & mark))
 392                        i++;
 393                if (cnt < i)
 394                        break; /* No more interesting hunks */
 395                hunk_begin = i;
 396                for (j = i + 1; j <= cnt; j++) {
 397                        if (!(sline[j].flag & mark)) {
 398                                /* Look beyond the end to see if there
 399                                 * is an interesting line after this
 400                                 * hunk within context span.
 401                                 */
 402                                unsigned long la; /* lookahead */
 403                                int contin = 0;
 404                                la = adjust_hunk_tail(sline, all_mask,
 405                                                     hunk_begin, j);
 406                                la = (la + context < cnt + 1) ?
 407                                        (la + context) : cnt + 1;
 408                                while (j <= --la) {
 409                                        if (sline[la].flag & mark) {
 410                                                contin = 1;
 411                                                break;
 412                                        }
 413                                }
 414                                if (!contin)
 415                                        break;
 416                                j = la;
 417                        }
 418                }
 419                hunk_end = j;
 420
 421                /* [i..hunk_end) are interesting.  Now is it really
 422                 * interesting?  We check if there are only two versions
 423                 * and the result matches one of them.  That is, we look
 424                 * at:
 425                 *   (+) line, which records lines added to which parents;
 426                 *       this line appears in the result.
 427                 *   (-) line, which records from what parents the line
 428                 *       was removed; this line does not appear in the result.
 429                 * then check the set of parents the result has difference
 430                 * from, from all lines.  If there are lines that has
 431                 * different set of parents that the result has differences
 432                 * from, that means we have more than two versions.
 433                 *
 434                 * Even when we have only two versions, if the result does
 435                 * not match any of the parents, the it should be considered
 436                 * interesting.  In such a case, we would have all '+' line.
 437                 * After passing the above "two versions" test, that would
 438                 * appear as "the same set of parents" to be "all parents".
 439                 */
 440                same_diff = 0;
 441                has_interesting = 0;
 442                for (j = i; j < hunk_end && !has_interesting; j++) {
 443                        unsigned long this_diff = sline[j].flag & all_mask;
 444                        struct lline *ll = sline[j].lost_head;
 445                        if (this_diff) {
 446                                /* This has some changes.  Is it the
 447                                 * same as others?
 448                                 */
 449                                if (!same_diff)
 450                                        same_diff = this_diff;
 451                                else if (same_diff != this_diff) {
 452                                        has_interesting = 1;
 453                                        break;
 454                                }
 455                        }
 456                        while (ll && !has_interesting) {
 457                                /* Lost this line from these parents;
 458                                 * who are they?  Are they the same?
 459                                 */
 460                                this_diff = ll->parent_map;
 461                                if (!same_diff)
 462                                        same_diff = this_diff;
 463                                else if (same_diff != this_diff) {
 464                                        has_interesting = 1;
 465                                }
 466                                ll = ll->next;
 467                        }
 468                }
 469
 470                if (!has_interesting && same_diff != all_mask) {
 471                        /* This hunk is not that interesting after all */
 472                        for (j = hunk_begin; j < hunk_end; j++)
 473                                sline[j].flag &= ~mark;
 474                }
 475                i = hunk_end;
 476        }
 477
 478        has_interesting = give_context(sline, cnt, num_parent);
 479        return has_interesting;
 480}
 481
 482static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
 483{
 484        l0 = sline[l0].p_lno[n];
 485        l1 = sline[l1].p_lno[n];
 486        printf(" -%lu,%lu", l0, l1-l0-null_context);
 487}
 488
 489static int hunk_comment_line(const char *bol)
 490{
 491        int ch;
 492
 493        if (!bol)
 494                return 0;
 495        ch = *bol & 0xff;
 496        return (isalpha(ch) || ch == '_' || ch == '$');
 497}
 498
 499static void dump_sline(struct sline *sline, unsigned long cnt, int num_parent,
 500                       int use_color)
 501{
 502        unsigned long mark = (1UL<<num_parent);
 503        unsigned long no_pre_delete = (2UL<<num_parent);
 504        int i;
 505        unsigned long lno = 0;
 506        const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
 507        const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
 508        const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
 509        const char *c_plain = diff_get_color(use_color, DIFF_PLAIN);
 510        const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 511
 512        if (!cnt)
 513                return; /* result deleted */
 514
 515        while (1) {
 516                struct sline *sl = &sline[lno];
 517                unsigned long hunk_end;
 518                unsigned long rlines;
 519                const char *hunk_comment = NULL;
 520                unsigned long null_context = 0;
 521
 522                while (lno <= cnt && !(sline[lno].flag & mark)) {
 523                        if (hunk_comment_line(sline[lno].bol))
 524                                hunk_comment = sline[lno].bol;
 525                        lno++;
 526                }
 527                if (cnt < lno)
 528                        break;
 529                else {
 530                        for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
 531                                if (!(sline[hunk_end].flag & mark))
 532                                        break;
 533                }
 534                rlines = hunk_end - lno;
 535                if (cnt < hunk_end)
 536                        rlines--; /* pointing at the last delete hunk */
 537
 538                if (!context) {
 539                        /*
 540                         * Even when running with --unified=0, all
 541                         * lines in the hunk needs to be processed in
 542                         * the loop below in order to show the
 543                         * deletion recorded in lost_head.  However,
 544                         * we do not want to show the resulting line
 545                         * with all blank context markers in such a
 546                         * case.  Compensate.
 547                         */
 548                        unsigned long j;
 549                        for (j = lno; j < hunk_end; j++)
 550                                if (!(sline[j].flag & (mark-1)))
 551                                        null_context++;
 552                        rlines -= null_context;
 553                }
 554
 555                fputs(c_frag, stdout);
 556                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 557                for (i = 0; i < num_parent; i++)
 558                        show_parent_lno(sline, lno, hunk_end, i, null_context);
 559                printf(" +%lu,%lu ", lno+1, rlines);
 560                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 561
 562                if (hunk_comment) {
 563                        int comment_end = 0;
 564                        for (i = 0; i < 40; i++) {
 565                                int ch = hunk_comment[i] & 0xff;
 566                                if (!ch || ch == '\n')
 567                                        break;
 568                                if (!isspace(ch))
 569                                    comment_end = i;
 570                        }
 571                        if (comment_end)
 572                                putchar(' ');
 573                        for (i = 0; i < comment_end; i++)
 574                                putchar(hunk_comment[i]);
 575                }
 576
 577                printf("%s\n", c_reset);
 578                while (lno < hunk_end) {
 579                        struct lline *ll;
 580                        int j;
 581                        unsigned long p_mask;
 582                        sl = &sline[lno++];
 583                        ll = (sl->flag & no_pre_delete) ? NULL : sl->lost_head;
 584                        while (ll) {
 585                                fputs(c_old, stdout);
 586                                for (j = 0; j < num_parent; j++) {
 587                                        if (ll->parent_map & (1UL<<j))
 588                                                putchar('-');
 589                                        else
 590                                                putchar(' ');
 591                                }
 592                                printf("%s%s\n", ll->line, c_reset);
 593                                ll = ll->next;
 594                        }
 595                        if (cnt < lno)
 596                                break;
 597                        p_mask = 1;
 598                        if (!(sl->flag & (mark-1))) {
 599                                /*
 600                                 * This sline was here to hang the
 601                                 * lost lines in front of it.
 602                                 */
 603                                if (!context)
 604                                        continue;
 605                                fputs(c_plain, stdout);
 606                        }
 607                        else
 608                                fputs(c_new, stdout);
 609                        for (j = 0; j < num_parent; j++) {
 610                                if (p_mask & sl->flag)
 611                                        putchar('+');
 612                                else
 613                                        putchar(' ');
 614                                p_mask <<= 1;
 615                        }
 616                        printf("%.*s%s\n", sl->len, sl->bol, c_reset);
 617                }
 618        }
 619}
 620
 621static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 622                               int i, int j)
 623{
 624        /* We have already examined parent j and we know parent i
 625         * and parent j are the same, so reuse the combined result
 626         * of parent j for parent i.
 627         */
 628        unsigned long lno, imask, jmask;
 629        imask = (1UL<<i);
 630        jmask = (1UL<<j);
 631
 632        for (lno = 0; lno <= cnt; lno++) {
 633                struct lline *ll = sline->lost_head;
 634                sline->p_lno[i] = sline->p_lno[j];
 635                while (ll) {
 636                        if (ll->parent_map & jmask)
 637                                ll->parent_map |= imask;
 638                        ll = ll->next;
 639                }
 640                if (sline->flag & jmask)
 641                        sline->flag |= imask;
 642                sline++;
 643        }
 644        /* the overall size of the file (sline[cnt]) */
 645        sline->p_lno[i] = sline->p_lno[j];
 646}
 647
 648static void dump_quoted_path(const char *head,
 649                             const char *prefix,
 650                             const char *path,
 651                             const char *c_meta, const char *c_reset)
 652{
 653        static struct strbuf buf = STRBUF_INIT;
 654
 655        strbuf_reset(&buf);
 656        strbuf_addstr(&buf, c_meta);
 657        strbuf_addstr(&buf, head);
 658        quote_two_c_style(&buf, prefix, path, 0);
 659        strbuf_addstr(&buf, c_reset);
 660        puts(buf.buf);
 661}
 662
 663static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 664                            int dense, struct rev_info *rev)
 665{
 666        struct diff_options *opt = &rev->diffopt;
 667        unsigned long result_size, cnt, lno;
 668        char *result, *cp;
 669        struct sline *sline; /* survived lines */
 670        int mode_differs = 0;
 671        int i, show_hunks;
 672        int working_tree_file = is_null_sha1(elem->sha1);
 673        int abbrev = DIFF_OPT_TST(opt, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
 674        mmfile_t result_file;
 675
 676        context = opt->context;
 677        /* Read the result of merge first */
 678        if (!working_tree_file)
 679                result = grab_blob(elem->sha1, &result_size);
 680        else {
 681                /* Used by diff-tree to read from the working tree */
 682                struct stat st;
 683                int fd = -1;
 684
 685                if (lstat(elem->path, &st) < 0)
 686                        goto deleted_file;
 687
 688                if (S_ISLNK(st.st_mode)) {
 689                        size_t len = xsize_t(st.st_size);
 690                        result_size = len;
 691                        result = xmalloc(len + 1);
 692                        if (result_size != readlink(elem->path, result, len)) {
 693                                error("readlink(%s): %s", elem->path,
 694                                      strerror(errno));
 695                                return;
 696                        }
 697                        result[len] = 0;
 698                        elem->mode = canon_mode(st.st_mode);
 699                }
 700                else if (0 <= (fd = open(elem->path, O_RDONLY)) &&
 701                         !fstat(fd, &st)) {
 702                        size_t len = xsize_t(st.st_size);
 703                        ssize_t done;
 704                        int is_file, i;
 705
 706                        elem->mode = canon_mode(st.st_mode);
 707                        /* if symlinks don't work, assume symlink if all parents
 708                         * are symlinks
 709                         */
 710                        is_file = has_symlinks;
 711                        for (i = 0; !is_file && i < num_parent; i++)
 712                                is_file = !S_ISLNK(elem->parent[i].mode);
 713                        if (!is_file)
 714                                elem->mode = canon_mode(S_IFLNK);
 715
 716                        result_size = len;
 717                        result = xmalloc(len + 1);
 718
 719                        done = read_in_full(fd, result, len);
 720                        if (done < 0)
 721                                die("read error '%s'", elem->path);
 722                        else if (done < len)
 723                                die("early EOF '%s'", elem->path);
 724
 725                        result[len] = 0;
 726
 727                        /* If not a fake symlink, apply filters, e.g. autocrlf */
 728                        if (is_file) {
 729                                struct strbuf buf;
 730
 731                                strbuf_init(&buf, 0);
 732                                if (convert_to_git(elem->path, result, len, &buf, safe_crlf)) {
 733                                        free(result);
 734                                        result = strbuf_detach(&buf, &len);
 735                                        result_size = len;
 736                                }
 737                        }
 738                }
 739                else {
 740                deleted_file:
 741                        result_size = 0;
 742                        elem->mode = 0;
 743                        result = xcalloc(1, 1);
 744                }
 745
 746                if (0 <= fd)
 747                        close(fd);
 748        }
 749
 750        for (cnt = 0, cp = result; cp < result + result_size; cp++) {
 751                if (*cp == '\n')
 752                        cnt++;
 753        }
 754        if (result_size && result[result_size-1] != '\n')
 755                cnt++; /* incomplete line */
 756
 757        sline = xcalloc(cnt+2, sizeof(*sline));
 758        sline[0].bol = result;
 759        for (lno = 0; lno <= cnt + 1; lno++) {
 760                sline[lno].lost_tail = &sline[lno].lost_head;
 761                sline[lno].flag = 0;
 762        }
 763        for (lno = 0, cp = result; cp < result + result_size; cp++) {
 764                if (*cp == '\n') {
 765                        sline[lno].len = cp - sline[lno].bol;
 766                        lno++;
 767                        if (lno < cnt)
 768                                sline[lno].bol = cp + 1;
 769                }
 770        }
 771        if (result_size && result[result_size-1] != '\n')
 772                sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
 773
 774        result_file.ptr = result;
 775        result_file.size = result_size;
 776
 777        /* Even p_lno[cnt+1] is valid -- that is for the end line number
 778         * for deletion hunk at the end.
 779         */
 780        sline[0].p_lno = xcalloc((cnt+2) * num_parent, sizeof(unsigned long));
 781        for (lno = 0; lno <= cnt; lno++)
 782                sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
 783
 784        for (i = 0; i < num_parent; i++) {
 785                int j;
 786                for (j = 0; j < i; j++) {
 787                        if (!hashcmp(elem->parent[i].sha1,
 788                                     elem->parent[j].sha1)) {
 789                                reuse_combine_diff(sline, cnt, i, j);
 790                                break;
 791                        }
 792                }
 793                if (i <= j)
 794                        combine_diff(elem->parent[i].sha1, &result_file, sline,
 795                                     cnt, i, num_parent);
 796                if (elem->parent[i].mode != elem->mode)
 797                        mode_differs = 1;
 798        }
 799
 800        show_hunks = make_hunks(sline, cnt, num_parent, dense);
 801
 802        if (show_hunks || mode_differs || working_tree_file) {
 803                const char *abb;
 804                int use_color = DIFF_OPT_TST(opt, COLOR_DIFF);
 805                const char *c_meta = diff_get_color(use_color, DIFF_METAINFO);
 806                const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 807                int added = 0;
 808                int deleted = 0;
 809
 810                if (rev->loginfo && !rev->no_commit_id)
 811                        show_log(rev);
 812                dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
 813                                 "", elem->path, c_meta, c_reset);
 814                printf("%sindex ", c_meta);
 815                for (i = 0; i < num_parent; i++) {
 816                        abb = find_unique_abbrev(elem->parent[i].sha1,
 817                                                 abbrev);
 818                        printf("%s%s", i ? "," : "", abb);
 819                }
 820                abb = find_unique_abbrev(elem->sha1, abbrev);
 821                printf("..%s%s\n", abb, c_reset);
 822
 823                if (mode_differs) {
 824                        deleted = !elem->mode;
 825
 826                        /* We say it was added if nobody had it */
 827                        added = !deleted;
 828                        for (i = 0; added && i < num_parent; i++)
 829                                if (elem->parent[i].status !=
 830                                    DIFF_STATUS_ADDED)
 831                                        added = 0;
 832                        if (added)
 833                                printf("%snew file mode %06o",
 834                                       c_meta, elem->mode);
 835                        else {
 836                                if (deleted)
 837                                        printf("%sdeleted file ", c_meta);
 838                                printf("mode ");
 839                                for (i = 0; i < num_parent; i++) {
 840                                        printf("%s%06o", i ? "," : "",
 841                                               elem->parent[i].mode);
 842                                }
 843                                if (elem->mode)
 844                                        printf("..%06o", elem->mode);
 845                        }
 846                        printf("%s\n", c_reset);
 847                }
 848                if (added)
 849                        dump_quoted_path("--- ", "", "/dev/null",
 850                                         c_meta, c_reset);
 851                else
 852                        dump_quoted_path("--- ", opt->a_prefix, elem->path,
 853                                         c_meta, c_reset);
 854                if (deleted)
 855                        dump_quoted_path("+++ ", "", "/dev/null",
 856                                         c_meta, c_reset);
 857                else
 858                        dump_quoted_path("+++ ", opt->b_prefix, elem->path,
 859                                         c_meta, c_reset);
 860                dump_sline(sline, cnt, num_parent,
 861                           DIFF_OPT_TST(opt, COLOR_DIFF));
 862        }
 863        free(result);
 864
 865        for (lno = 0; lno < cnt; lno++) {
 866                if (sline[lno].lost_head) {
 867                        struct lline *ll = sline[lno].lost_head;
 868                        while (ll) {
 869                                struct lline *tmp = ll;
 870                                ll = ll->next;
 871                                free(tmp);
 872                        }
 873                }
 874        }
 875        free(sline[0].p_lno);
 876        free(sline);
 877}
 878
 879#define COLONS "::::::::::::::::::::::::::::::::"
 880
 881static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
 882{
 883        struct diff_options *opt = &rev->diffopt;
 884        int i, offset;
 885        const char *prefix;
 886        int line_termination, inter_name_termination;
 887
 888        line_termination = opt->line_termination;
 889        inter_name_termination = '\t';
 890        if (!line_termination)
 891                inter_name_termination = 0;
 892
 893        if (rev->loginfo && !rev->no_commit_id)
 894                show_log(rev);
 895
 896        if (opt->output_format & DIFF_FORMAT_RAW) {
 897                offset = strlen(COLONS) - num_parent;
 898                if (offset < 0)
 899                        offset = 0;
 900                prefix = COLONS + offset;
 901
 902                /* Show the modes */
 903                for (i = 0; i < num_parent; i++) {
 904                        printf("%s%06o", prefix, p->parent[i].mode);
 905                        prefix = " ";
 906                }
 907                printf("%s%06o", prefix, p->mode);
 908
 909                /* Show sha1's */
 910                for (i = 0; i < num_parent; i++)
 911                        printf(" %s", diff_unique_abbrev(p->parent[i].sha1,
 912                                                         opt->abbrev));
 913                printf(" %s ", diff_unique_abbrev(p->sha1, opt->abbrev));
 914        }
 915
 916        if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
 917                for (i = 0; i < num_parent; i++)
 918                        putchar(p->parent[i].status);
 919                putchar(inter_name_termination);
 920        }
 921
 922        write_name_quoted(p->path, stdout, line_termination);
 923}
 924
 925void show_combined_diff(struct combine_diff_path *p,
 926                       int num_parent,
 927                       int dense,
 928                       struct rev_info *rev)
 929{
 930        struct diff_options *opt = &rev->diffopt;
 931        if (!p->len)
 932                return;
 933        if (opt->output_format & (DIFF_FORMAT_RAW |
 934                                  DIFF_FORMAT_NAME |
 935                                  DIFF_FORMAT_NAME_STATUS))
 936                show_raw_diff(p, num_parent, rev);
 937        else if (opt->output_format & DIFF_FORMAT_PATCH)
 938                show_patch_diff(p, num_parent, dense, rev);
 939}
 940
 941void diff_tree_combined(const unsigned char *sha1,
 942                        const unsigned char parent[][20],
 943                        int num_parent,
 944                        int dense,
 945                        struct rev_info *rev)
 946{
 947        struct diff_options *opt = &rev->diffopt;
 948        struct diff_options diffopts;
 949        struct combine_diff_path *p, *paths = NULL;
 950        int i, num_paths, needsep, show_log_first;
 951
 952        diffopts = *opt;
 953        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
 954        DIFF_OPT_SET(&diffopts, RECURSIVE);
 955        DIFF_OPT_CLR(&diffopts, ALLOW_EXTERNAL);
 956
 957        show_log_first = !!rev->loginfo && !rev->no_commit_id;
 958        needsep = 0;
 959        /* find set of paths that everybody touches */
 960        for (i = 0; i < num_parent; i++) {
 961                /* show stat against the first parent even
 962                 * when doing combined diff.
 963                 */
 964                int stat_opt = (opt->output_format &
 965                                (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
 966                if (i == 0 && stat_opt)
 967                        diffopts.output_format = stat_opt;
 968                else
 969                        diffopts.output_format = DIFF_FORMAT_NO_OUTPUT;
 970                diff_tree_sha1(parent[i], sha1, "", &diffopts);
 971                diffcore_std(&diffopts);
 972                paths = intersect_paths(paths, i, num_parent);
 973
 974                if (show_log_first && i == 0) {
 975                        show_log(rev);
 976                        if (rev->verbose_header && opt->output_format)
 977                                putchar(opt->line_termination);
 978                }
 979                diff_flush(&diffopts);
 980        }
 981
 982        /* find out surviving paths */
 983        for (num_paths = 0, p = paths; p; p = p->next) {
 984                if (p->len)
 985                        num_paths++;
 986        }
 987        if (num_paths) {
 988                if (opt->output_format & (DIFF_FORMAT_RAW |
 989                                          DIFF_FORMAT_NAME |
 990                                          DIFF_FORMAT_NAME_STATUS)) {
 991                        for (p = paths; p; p = p->next) {
 992                                if (p->len)
 993                                        show_raw_diff(p, num_parent, rev);
 994                        }
 995                        needsep = 1;
 996                }
 997                else if (opt->output_format &
 998                         (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
 999                        needsep = 1;
1000                if (opt->output_format & DIFF_FORMAT_PATCH) {
1001                        if (needsep)
1002                                putchar(opt->line_termination);
1003                        for (p = paths; p; p = p->next) {
1004                                if (p->len)
1005                                        show_patch_diff(p, num_parent, dense,
1006                                                        rev);
1007                        }
1008                }
1009        }
1010
1011        /* Clean things up */
1012        while (paths) {
1013                struct combine_diff_path *tmp = paths;
1014                paths = paths->next;
1015                free(tmp);
1016        }
1017}
1018
1019void diff_tree_combined_merge(const unsigned char *sha1,
1020                             int dense, struct rev_info *rev)
1021{
1022        int num_parent;
1023        const unsigned char (*parent)[20];
1024        struct commit *commit = lookup_commit(sha1);
1025        struct commit_list *parents;
1026
1027        /* count parents */
1028        for (parents = commit->parents, num_parent = 0;
1029             parents;
1030             parents = parents->next, num_parent++)
1031                ; /* nothing */
1032
1033        parent = xmalloc(num_parent * sizeof(*parent));
1034        for (parents = commit->parents, num_parent = 0;
1035             parents;
1036             parents = parents->next, num_parent++)
1037                hashcpy((unsigned char*)(parent + num_parent),
1038                        parents->item->object.sha1);
1039        diff_tree_combined(sha1, parent, num_parent, dense, rev);
1040}