combine-diff.con commit sequencer: refactor sequencer_add_exec_commands() to work on a todo_list (683153a)
   1#include "cache.h"
   2#include "object-store.h"
   3#include "commit.h"
   4#include "blob.h"
   5#include "diff.h"
   6#include "diffcore.h"
   7#include "quote.h"
   8#include "xdiff-interface.h"
   9#include "xdiff/xmacros.h"
  10#include "log-tree.h"
  11#include "refs.h"
  12#include "userdiff.h"
  13#include "sha1-array.h"
  14#include "revision.h"
  15
  16static int compare_paths(const struct combine_diff_path *one,
  17                          const struct diff_filespec *two)
  18{
  19        if (!S_ISDIR(one->mode) && !S_ISDIR(two->mode))
  20                return strcmp(one->path, two->path);
  21
  22        return base_name_compare(one->path, strlen(one->path), one->mode,
  23                                 two->path, strlen(two->path), two->mode);
  24}
  25
  26static struct combine_diff_path *intersect_paths(struct combine_diff_path *curr, int n, int num_parent)
  27{
  28        struct diff_queue_struct *q = &diff_queued_diff;
  29        struct combine_diff_path *p, **tail = &curr;
  30        int i, cmp;
  31
  32        if (!n) {
  33                for (i = 0; i < q->nr; i++) {
  34                        int len;
  35                        const char *path;
  36                        if (diff_unmodified_pair(q->queue[i]))
  37                                continue;
  38                        path = q->queue[i]->two->path;
  39                        len = strlen(path);
  40                        p = xmalloc(combine_diff_path_size(num_parent, len));
  41                        p->path = (char *) &(p->parent[num_parent]);
  42                        memcpy(p->path, path, len);
  43                        p->path[len] = 0;
  44                        p->next = NULL;
  45                        memset(p->parent, 0,
  46                               sizeof(p->parent[0]) * num_parent);
  47
  48                        oidcpy(&p->oid, &q->queue[i]->two->oid);
  49                        p->mode = q->queue[i]->two->mode;
  50                        oidcpy(&p->parent[n].oid, &q->queue[i]->one->oid);
  51                        p->parent[n].mode = q->queue[i]->one->mode;
  52                        p->parent[n].status = q->queue[i]->status;
  53                        *tail = p;
  54                        tail = &p->next;
  55                }
  56                return curr;
  57        }
  58
  59        /*
  60         * paths in curr (linked list) and q->queue[] (array) are
  61         * both sorted in the tree order.
  62         */
  63        i = 0;
  64        while ((p = *tail) != NULL) {
  65                cmp = ((i >= q->nr)
  66                       ? -1 : compare_paths(p, q->queue[i]->two));
  67
  68                if (cmp < 0) {
  69                        /* p->path not in q->queue[]; drop it */
  70                        *tail = p->next;
  71                        free(p);
  72                        continue;
  73                }
  74
  75                if (cmp > 0) {
  76                        /* q->queue[i] not in p->path; skip it */
  77                        i++;
  78                        continue;
  79                }
  80
  81                oidcpy(&p->parent[n].oid, &q->queue[i]->one->oid);
  82                p->parent[n].mode = q->queue[i]->one->mode;
  83                p->parent[n].status = q->queue[i]->status;
  84
  85                tail = &p->next;
  86                i++;
  87        }
  88        return curr;
  89}
  90
  91/* Lines lost from parent */
  92struct lline {
  93        struct lline *next, *prev;
  94        int len;
  95        unsigned long parent_map;
  96        char line[FLEX_ARRAY];
  97};
  98
  99/* Lines lost from current parent (before coalescing) */
 100struct plost {
 101        struct lline *lost_head, *lost_tail;
 102        int len;
 103};
 104
 105/* Lines surviving in the merge result */
 106struct sline {
 107        /* Accumulated and coalesced lost lines */
 108        struct lline *lost;
 109        int lenlost;
 110        struct plost plost;
 111        char *bol;
 112        int len;
 113        /* bit 0 up to (N-1) are on if the parent has this line (i.e.
 114         * we did not change it).
 115         * bit N is used for "interesting" lines, including context.
 116         * bit (N+1) is used for "do not show deletion before this".
 117         */
 118        unsigned long flag;
 119        unsigned long *p_lno;
 120};
 121
 122static int match_string_spaces(const char *line1, int len1,
 123                               const char *line2, int len2,
 124                               long flags)
 125{
 126        if (flags & XDF_WHITESPACE_FLAGS) {
 127                for (; len1 > 0 && XDL_ISSPACE(line1[len1 - 1]); len1--);
 128                for (; len2 > 0 && XDL_ISSPACE(line2[len2 - 1]); len2--);
 129        }
 130
 131        if (!(flags & (XDF_IGNORE_WHITESPACE | XDF_IGNORE_WHITESPACE_CHANGE)))
 132                return (len1 == len2 && !memcmp(line1, line2, len1));
 133
 134        while (len1 > 0 && len2 > 0) {
 135                len1--;
 136                len2--;
 137                if (XDL_ISSPACE(line1[len1]) || XDL_ISSPACE(line2[len2])) {
 138                        if ((flags & XDF_IGNORE_WHITESPACE_CHANGE) &&
 139                            (!XDL_ISSPACE(line1[len1]) || !XDL_ISSPACE(line2[len2])))
 140                                return 0;
 141
 142                        for (; len1 > 0 && XDL_ISSPACE(line1[len1]); len1--);
 143                        for (; len2 > 0 && XDL_ISSPACE(line2[len2]); len2--);
 144                }
 145                if (line1[len1] != line2[len2])
 146                        return 0;
 147        }
 148
 149        if (flags & XDF_IGNORE_WHITESPACE) {
 150                /* Consume remaining spaces */
 151                for (; len1 > 0 && XDL_ISSPACE(line1[len1 - 1]); len1--);
 152                for (; len2 > 0 && XDL_ISSPACE(line2[len2 - 1]); len2--);
 153        }
 154
 155        /* We matched full line1 and line2 */
 156        if (!len1 && !len2)
 157                return 1;
 158
 159        return 0;
 160}
 161
 162enum coalesce_direction { MATCH, BASE, NEW };
 163
 164/* Coalesce new lines into base by finding LCS */
 165static struct lline *coalesce_lines(struct lline *base, int *lenbase,
 166                                    struct lline *newline, int lennew,
 167                                    unsigned long parent, long flags)
 168{
 169        int **lcs;
 170        enum coalesce_direction **directions;
 171        struct lline *baseend, *newend = NULL;
 172        int i, j, origbaselen = *lenbase;
 173
 174        if (newline == NULL)
 175                return base;
 176
 177        if (base == NULL) {
 178                *lenbase = lennew;
 179                return newline;
 180        }
 181
 182        /*
 183         * Coalesce new lines into base by finding the LCS
 184         * - Create the table to run dynamic programming
 185         * - Compute the LCS
 186         * - Then reverse read the direction structure:
 187         *   - If we have MATCH, assign parent to base flag, and consume
 188         *   both baseend and newend
 189         *   - Else if we have BASE, consume baseend
 190         *   - Else if we have NEW, insert newend lline into base and
 191         *   consume newend
 192         */
 193        lcs = xcalloc(st_add(origbaselen, 1), sizeof(int*));
 194        directions = xcalloc(st_add(origbaselen, 1), sizeof(enum coalesce_direction*));
 195        for (i = 0; i < origbaselen + 1; i++) {
 196                lcs[i] = xcalloc(st_add(lennew, 1), sizeof(int));
 197                directions[i] = xcalloc(st_add(lennew, 1), sizeof(enum coalesce_direction));
 198                directions[i][0] = BASE;
 199        }
 200        for (j = 1; j < lennew + 1; j++)
 201                directions[0][j] = NEW;
 202
 203        for (i = 1, baseend = base; i < origbaselen + 1; i++) {
 204                for (j = 1, newend = newline; j < lennew + 1; j++) {
 205                        if (match_string_spaces(baseend->line, baseend->len,
 206                                                newend->line, newend->len, flags)) {
 207                                lcs[i][j] = lcs[i - 1][j - 1] + 1;
 208                                directions[i][j] = MATCH;
 209                        } else if (lcs[i][j - 1] >= lcs[i - 1][j]) {
 210                                lcs[i][j] = lcs[i][j - 1];
 211                                directions[i][j] = NEW;
 212                        } else {
 213                                lcs[i][j] = lcs[i - 1][j];
 214                                directions[i][j] = BASE;
 215                        }
 216                        if (newend->next)
 217                                newend = newend->next;
 218                }
 219                if (baseend->next)
 220                        baseend = baseend->next;
 221        }
 222
 223        for (i = 0; i < origbaselen + 1; i++)
 224                free(lcs[i]);
 225        free(lcs);
 226
 227        /* At this point, baseend and newend point to the end of each lists */
 228        i--;
 229        j--;
 230        while (i != 0 || j != 0) {
 231                if (directions[i][j] == MATCH) {
 232                        baseend->parent_map |= 1<<parent;
 233                        baseend = baseend->prev;
 234                        newend = newend->prev;
 235                        i--;
 236                        j--;
 237                } else if (directions[i][j] == NEW) {
 238                        struct lline *lline;
 239
 240                        lline = newend;
 241                        /* Remove lline from new list and update newend */
 242                        if (lline->prev)
 243                                lline->prev->next = lline->next;
 244                        else
 245                                newline = lline->next;
 246                        if (lline->next)
 247                                lline->next->prev = lline->prev;
 248
 249                        newend = lline->prev;
 250                        j--;
 251
 252                        /* Add lline to base list */
 253                        if (baseend) {
 254                                lline->next = baseend->next;
 255                                lline->prev = baseend;
 256                                if (lline->prev)
 257                                        lline->prev->next = lline;
 258                        }
 259                        else {
 260                                lline->next = base;
 261                                base = lline;
 262                        }
 263                        (*lenbase)++;
 264
 265                        if (lline->next)
 266                                lline->next->prev = lline;
 267
 268                } else {
 269                        baseend = baseend->prev;
 270                        i--;
 271                }
 272        }
 273
 274        newend = newline;
 275        while (newend) {
 276                struct lline *lline = newend;
 277                newend = newend->next;
 278                free(lline);
 279        }
 280
 281        for (i = 0; i < origbaselen + 1; i++)
 282                free(directions[i]);
 283        free(directions);
 284
 285        return base;
 286}
 287
 288static char *grab_blob(struct repository *r,
 289                       const struct object_id *oid, unsigned int mode,
 290                       unsigned long *size, struct userdiff_driver *textconv,
 291                       const char *path)
 292{
 293        char *blob;
 294        enum object_type type;
 295
 296        if (S_ISGITLINK(mode)) {
 297                struct strbuf buf = STRBUF_INIT;
 298                strbuf_addf(&buf, "Subproject commit %s\n", oid_to_hex(oid));
 299                *size = buf.len;
 300                blob = strbuf_detach(&buf, NULL);
 301        } else if (is_null_oid(oid)) {
 302                /* deleted blob */
 303                *size = 0;
 304                return xcalloc(1, 1);
 305        } else if (textconv) {
 306                struct diff_filespec *df = alloc_filespec(path);
 307                fill_filespec(df, oid, 1, mode);
 308                *size = fill_textconv(r, textconv, df, &blob);
 309                free_filespec(df);
 310        } else {
 311                blob = read_object_file(oid, &type, size);
 312                if (type != OBJ_BLOB)
 313                        die("object '%s' is not a blob!", oid_to_hex(oid));
 314        }
 315        return blob;
 316}
 317
 318static void append_lost(struct sline *sline, int n, const char *line, int len)
 319{
 320        struct lline *lline;
 321        unsigned long this_mask = (1UL<<n);
 322        if (line[len-1] == '\n')
 323                len--;
 324
 325        FLEX_ALLOC_MEM(lline, line, line, len);
 326        lline->len = len;
 327        lline->next = NULL;
 328        lline->prev = sline->plost.lost_tail;
 329        if (lline->prev)
 330                lline->prev->next = lline;
 331        else
 332                sline->plost.lost_head = lline;
 333        sline->plost.lost_tail = lline;
 334        sline->plost.len++;
 335        lline->parent_map = this_mask;
 336}
 337
 338struct combine_diff_state {
 339        unsigned int lno;
 340        int ob, on, nb, nn;
 341        unsigned long nmask;
 342        int num_parent;
 343        int n;
 344        struct sline *sline;
 345        struct sline *lost_bucket;
 346};
 347
 348static void consume_hunk(void *state_,
 349                         long ob, long on,
 350                         long nb, long nn,
 351                         const char *funcline, long funclen)
 352{
 353        struct combine_diff_state *state = state_;
 354
 355        state->ob = ob;
 356        state->on = on;
 357        state->nb = nb;
 358        state->nn = nn;
 359        state->lno = state->nb;
 360        if (state->nn == 0) {
 361                /* @@ -X,Y +N,0 @@ removed Y lines
 362                 * that would have come *after* line N
 363                 * in the result.  Our lost buckets hang
 364                 * to the line after the removed lines,
 365                 *
 366                 * Note that this is correct even when N == 0,
 367                 * in which case the hunk removes the first
 368                 * line in the file.
 369                 */
 370                state->lost_bucket = &state->sline[state->nb];
 371                if (!state->nb)
 372                        state->nb = 1;
 373        } else {
 374                state->lost_bucket = &state->sline[state->nb-1];
 375        }
 376        if (!state->sline[state->nb-1].p_lno)
 377                state->sline[state->nb-1].p_lno =
 378                        xcalloc(state->num_parent, sizeof(unsigned long));
 379        state->sline[state->nb-1].p_lno[state->n] = state->ob;
 380}
 381
 382static void consume_line(void *state_, char *line, unsigned long len)
 383{
 384        struct combine_diff_state *state = state_;
 385        if (!state->lost_bucket)
 386                return; /* not in any hunk yet */
 387        switch (line[0]) {
 388        case '-':
 389                append_lost(state->lost_bucket, state->n, line+1, len-1);
 390                break;
 391        case '+':
 392                state->sline[state->lno-1].flag |= state->nmask;
 393                state->lno++;
 394                break;
 395        }
 396}
 397
 398static void combine_diff(struct repository *r,
 399                         const struct object_id *parent, unsigned int mode,
 400                         mmfile_t *result_file,
 401                         struct sline *sline, unsigned int cnt, int n,
 402                         int num_parent, int result_deleted,
 403                         struct userdiff_driver *textconv,
 404                         const char *path, long flags)
 405{
 406        unsigned int p_lno, lno;
 407        unsigned long nmask = (1UL << n);
 408        xpparam_t xpp;
 409        xdemitconf_t xecfg;
 410        mmfile_t parent_file;
 411        struct combine_diff_state state;
 412        unsigned long sz;
 413
 414        if (result_deleted)
 415                return; /* result deleted */
 416
 417        parent_file.ptr = grab_blob(r, parent, mode, &sz, textconv, path);
 418        parent_file.size = sz;
 419        memset(&xpp, 0, sizeof(xpp));
 420        xpp.flags = flags;
 421        memset(&xecfg, 0, sizeof(xecfg));
 422        memset(&state, 0, sizeof(state));
 423        state.nmask = nmask;
 424        state.sline = sline;
 425        state.lno = 1;
 426        state.num_parent = num_parent;
 427        state.n = n;
 428
 429        if (xdi_diff_outf(&parent_file, result_file, consume_hunk,
 430                          consume_line, &state, &xpp, &xecfg))
 431                die("unable to generate combined diff for %s",
 432                    oid_to_hex(parent));
 433        free(parent_file.ptr);
 434
 435        /* Assign line numbers for this parent.
 436         *
 437         * sline[lno].p_lno[n] records the first line number
 438         * (counting from 1) for parent N if the final hunk display
 439         * started by showing sline[lno] (possibly showing the lost
 440         * lines attached to it first).
 441         */
 442        for (lno = 0,  p_lno = 1; lno <= cnt; lno++) {
 443                struct lline *ll;
 444                sline[lno].p_lno[n] = p_lno;
 445
 446                /* Coalesce new lines */
 447                if (sline[lno].plost.lost_head) {
 448                        struct sline *sl = &sline[lno];
 449                        sl->lost = coalesce_lines(sl->lost, &sl->lenlost,
 450                                                  sl->plost.lost_head,
 451                                                  sl->plost.len, n, flags);
 452                        sl->plost.lost_head = sl->plost.lost_tail = NULL;
 453                        sl->plost.len = 0;
 454                }
 455
 456                /* How many lines would this sline advance the p_lno? */
 457                ll = sline[lno].lost;
 458                while (ll) {
 459                        if (ll->parent_map & nmask)
 460                                p_lno++; /* '-' means parent had it */
 461                        ll = ll->next;
 462                }
 463                if (lno < cnt && !(sline[lno].flag & nmask))
 464                        p_lno++; /* no '+' means parent had it */
 465        }
 466        sline[lno].p_lno[n] = p_lno; /* trailer */
 467}
 468
 469static unsigned long context = 3;
 470static char combine_marker = '@';
 471
 472static int interesting(struct sline *sline, unsigned long all_mask)
 473{
 474        /* If some parents lost lines here, or if we have added to
 475         * some parent, it is interesting.
 476         */
 477        return ((sline->flag & all_mask) || sline->lost);
 478}
 479
 480static unsigned long adjust_hunk_tail(struct sline *sline,
 481                                      unsigned long all_mask,
 482                                      unsigned long hunk_begin,
 483                                      unsigned long i)
 484{
 485        /* i points at the first uninteresting line.  If the last line
 486         * of the hunk was interesting only because it has some
 487         * deletion, then it is not all that interesting for the
 488         * purpose of giving trailing context lines.  This is because
 489         * we output '-' line and then unmodified sline[i-1] itself in
 490         * that case which gives us one extra context line.
 491         */
 492        if ((hunk_begin + 1 <= i) && !(sline[i-1].flag & all_mask))
 493                i--;
 494        return i;
 495}
 496
 497static unsigned long find_next(struct sline *sline,
 498                               unsigned long mark,
 499                               unsigned long i,
 500                               unsigned long cnt,
 501                               int look_for_uninteresting)
 502{
 503        /* We have examined up to i-1 and are about to look at i.
 504         * Find next interesting or uninteresting line.  Here,
 505         * "interesting" does not mean interesting(), but marked by
 506         * the give_context() function below (i.e. it includes context
 507         * lines that are not interesting to interesting() function
 508         * that are surrounded by interesting() ones.
 509         */
 510        while (i <= cnt)
 511                if (look_for_uninteresting
 512                    ? !(sline[i].flag & mark)
 513                    : (sline[i].flag & mark))
 514                        return i;
 515                else
 516                        i++;
 517        return i;
 518}
 519
 520static int give_context(struct sline *sline, unsigned long cnt, int num_parent)
 521{
 522        unsigned long all_mask = (1UL<<num_parent) - 1;
 523        unsigned long mark = (1UL<<num_parent);
 524        unsigned long no_pre_delete = (2UL<<num_parent);
 525        unsigned long i;
 526
 527        /* Two groups of interesting lines may have a short gap of
 528         * uninteresting lines.  Connect such groups to give them a
 529         * bit of context.
 530         *
 531         * We first start from what the interesting() function says,
 532         * and mark them with "mark", and paint context lines with the
 533         * mark.  So interesting() would still say false for such context
 534         * lines but they are treated as "interesting" in the end.
 535         */
 536        i = find_next(sline, mark, 0, cnt, 0);
 537        if (cnt < i)
 538                return 0;
 539
 540        while (i <= cnt) {
 541                unsigned long j = (context < i) ? (i - context) : 0;
 542                unsigned long k;
 543
 544                /* Paint a few lines before the first interesting line. */
 545                while (j < i) {
 546                        if (!(sline[j].flag & mark))
 547                                sline[j].flag |= no_pre_delete;
 548                        sline[j++].flag |= mark;
 549                }
 550
 551        again:
 552                /* we know up to i is to be included.  where does the
 553                 * next uninteresting one start?
 554                 */
 555                j = find_next(sline, mark, i, cnt, 1);
 556                if (cnt < j)
 557                        break; /* the rest are all interesting */
 558
 559                /* lookahead context lines */
 560                k = find_next(sline, mark, j, cnt, 0);
 561                j = adjust_hunk_tail(sline, all_mask, i, j);
 562
 563                if (k < j + context) {
 564                        /* k is interesting and [j,k) are not, but
 565                         * paint them interesting because the gap is small.
 566                         */
 567                        while (j < k)
 568                                sline[j++].flag |= mark;
 569                        i = k;
 570                        goto again;
 571                }
 572
 573                /* j is the first uninteresting line and there is
 574                 * no overlap beyond it within context lines.  Paint
 575                 * the trailing edge a bit.
 576                 */
 577                i = k;
 578                k = (j + context < cnt+1) ? j + context : cnt+1;
 579                while (j < k)
 580                        sline[j++].flag |= mark;
 581        }
 582        return 1;
 583}
 584
 585static int make_hunks(struct sline *sline, unsigned long cnt,
 586                       int num_parent, int dense)
 587{
 588        unsigned long all_mask = (1UL<<num_parent) - 1;
 589        unsigned long mark = (1UL<<num_parent);
 590        unsigned long i;
 591        int has_interesting = 0;
 592
 593        for (i = 0; i <= cnt; i++) {
 594                if (interesting(&sline[i], all_mask))
 595                        sline[i].flag |= mark;
 596                else
 597                        sline[i].flag &= ~mark;
 598        }
 599        if (!dense)
 600                return give_context(sline, cnt, num_parent);
 601
 602        /* Look at each hunk, and if we have changes from only one
 603         * parent, or the changes are the same from all but one
 604         * parent, mark that uninteresting.
 605         */
 606        i = 0;
 607        while (i <= cnt) {
 608                unsigned long j, hunk_begin, hunk_end;
 609                unsigned long same_diff;
 610                while (i <= cnt && !(sline[i].flag & mark))
 611                        i++;
 612                if (cnt < i)
 613                        break; /* No more interesting hunks */
 614                hunk_begin = i;
 615                for (j = i + 1; j <= cnt; j++) {
 616                        if (!(sline[j].flag & mark)) {
 617                                /* Look beyond the end to see if there
 618                                 * is an interesting line after this
 619                                 * hunk within context span.
 620                                 */
 621                                unsigned long la; /* lookahead */
 622                                int contin = 0;
 623                                la = adjust_hunk_tail(sline, all_mask,
 624                                                     hunk_begin, j);
 625                                la = (la + context < cnt + 1) ?
 626                                        (la + context) : cnt + 1;
 627                                while (la && j <= --la) {
 628                                        if (sline[la].flag & mark) {
 629                                                contin = 1;
 630                                                break;
 631                                        }
 632                                }
 633                                if (!contin)
 634                                        break;
 635                                j = la;
 636                        }
 637                }
 638                hunk_end = j;
 639
 640                /* [i..hunk_end) are interesting.  Now is it really
 641                 * interesting?  We check if there are only two versions
 642                 * and the result matches one of them.  That is, we look
 643                 * at:
 644                 *   (+) line, which records lines added to which parents;
 645                 *       this line appears in the result.
 646                 *   (-) line, which records from what parents the line
 647                 *       was removed; this line does not appear in the result.
 648                 * then check the set of parents the result has difference
 649                 * from, from all lines.  If there are lines that has
 650                 * different set of parents that the result has differences
 651                 * from, that means we have more than two versions.
 652                 *
 653                 * Even when we have only two versions, if the result does
 654                 * not match any of the parents, the it should be considered
 655                 * interesting.  In such a case, we would have all '+' line.
 656                 * After passing the above "two versions" test, that would
 657                 * appear as "the same set of parents" to be "all parents".
 658                 */
 659                same_diff = 0;
 660                has_interesting = 0;
 661                for (j = i; j < hunk_end && !has_interesting; j++) {
 662                        unsigned long this_diff = sline[j].flag & all_mask;
 663                        struct lline *ll = sline[j].lost;
 664                        if (this_diff) {
 665                                /* This has some changes.  Is it the
 666                                 * same as others?
 667                                 */
 668                                if (!same_diff)
 669                                        same_diff = this_diff;
 670                                else if (same_diff != this_diff) {
 671                                        has_interesting = 1;
 672                                        break;
 673                                }
 674                        }
 675                        while (ll && !has_interesting) {
 676                                /* Lost this line from these parents;
 677                                 * who are they?  Are they the same?
 678                                 */
 679                                this_diff = ll->parent_map;
 680                                if (!same_diff)
 681                                        same_diff = this_diff;
 682                                else if (same_diff != this_diff) {
 683                                        has_interesting = 1;
 684                                }
 685                                ll = ll->next;
 686                        }
 687                }
 688
 689                if (!has_interesting && same_diff != all_mask) {
 690                        /* This hunk is not that interesting after all */
 691                        for (j = hunk_begin; j < hunk_end; j++)
 692                                sline[j].flag &= ~mark;
 693                }
 694                i = hunk_end;
 695        }
 696
 697        has_interesting = give_context(sline, cnt, num_parent);
 698        return has_interesting;
 699}
 700
 701static void show_parent_lno(struct sline *sline, unsigned long l0, unsigned long l1, int n, unsigned long null_context)
 702{
 703        l0 = sline[l0].p_lno[n];
 704        l1 = sline[l1].p_lno[n];
 705        printf(" -%lu,%lu", l0, l1-l0-null_context);
 706}
 707
 708static int hunk_comment_line(const char *bol)
 709{
 710        int ch;
 711
 712        if (!bol)
 713                return 0;
 714        ch = *bol & 0xff;
 715        return (isalpha(ch) || ch == '_' || ch == '$');
 716}
 717
 718static void show_line_to_eol(const char *line, int len, const char *reset)
 719{
 720        int saw_cr_at_eol = 0;
 721        if (len < 0)
 722                len = strlen(line);
 723        saw_cr_at_eol = (len && line[len-1] == '\r');
 724
 725        printf("%.*s%s%s\n", len - saw_cr_at_eol, line,
 726               reset,
 727               saw_cr_at_eol ? "\r" : "");
 728}
 729
 730static void dump_sline(struct sline *sline, const char *line_prefix,
 731                       unsigned long cnt, int num_parent,
 732                       int use_color, int result_deleted)
 733{
 734        unsigned long mark = (1UL<<num_parent);
 735        unsigned long no_pre_delete = (2UL<<num_parent);
 736        int i;
 737        unsigned long lno = 0;
 738        const char *c_frag = diff_get_color(use_color, DIFF_FRAGINFO);
 739        const char *c_func = diff_get_color(use_color, DIFF_FUNCINFO);
 740        const char *c_new = diff_get_color(use_color, DIFF_FILE_NEW);
 741        const char *c_old = diff_get_color(use_color, DIFF_FILE_OLD);
 742        const char *c_context = diff_get_color(use_color, DIFF_CONTEXT);
 743        const char *c_reset = diff_get_color(use_color, DIFF_RESET);
 744
 745        if (result_deleted)
 746                return; /* result deleted */
 747
 748        while (1) {
 749                unsigned long hunk_end;
 750                unsigned long rlines;
 751                const char *hunk_comment = NULL;
 752                unsigned long null_context = 0;
 753
 754                while (lno <= cnt && !(sline[lno].flag & mark)) {
 755                        if (hunk_comment_line(sline[lno].bol))
 756                                hunk_comment = sline[lno].bol;
 757                        lno++;
 758                }
 759                if (cnt < lno)
 760                        break;
 761                else {
 762                        for (hunk_end = lno + 1; hunk_end <= cnt; hunk_end++)
 763                                if (!(sline[hunk_end].flag & mark))
 764                                        break;
 765                }
 766                rlines = hunk_end - lno;
 767                if (cnt < hunk_end)
 768                        rlines--; /* pointing at the last delete hunk */
 769
 770                if (!context) {
 771                        /*
 772                         * Even when running with --unified=0, all
 773                         * lines in the hunk needs to be processed in
 774                         * the loop below in order to show the
 775                         * deletion recorded in lost_head.  However,
 776                         * we do not want to show the resulting line
 777                         * with all blank context markers in such a
 778                         * case.  Compensate.
 779                         */
 780                        unsigned long j;
 781                        for (j = lno; j < hunk_end; j++)
 782                                if (!(sline[j].flag & (mark-1)))
 783                                        null_context++;
 784                        rlines -= null_context;
 785                }
 786
 787                printf("%s%s", line_prefix, c_frag);
 788                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 789                for (i = 0; i < num_parent; i++)
 790                        show_parent_lno(sline, lno, hunk_end, i, null_context);
 791                printf(" +%lu,%lu ", lno+1, rlines);
 792                for (i = 0; i <= num_parent; i++) putchar(combine_marker);
 793
 794                if (hunk_comment) {
 795                        int comment_end = 0;
 796                        for (i = 0; i < 40; i++) {
 797                                int ch = hunk_comment[i] & 0xff;
 798                                if (!ch || ch == '\n')
 799                                        break;
 800                                if (!isspace(ch))
 801                                    comment_end = i;
 802                        }
 803                        if (comment_end)
 804                                printf("%s%s %s%s", c_reset,
 805                                                    c_context, c_reset,
 806                                                    c_func);
 807                        for (i = 0; i < comment_end; i++)
 808                                putchar(hunk_comment[i]);
 809                }
 810
 811                printf("%s\n", c_reset);
 812                while (lno < hunk_end) {
 813                        struct lline *ll;
 814                        int j;
 815                        unsigned long p_mask;
 816                        struct sline *sl = &sline[lno++];
 817                        ll = (sl->flag & no_pre_delete) ? NULL : sl->lost;
 818                        while (ll) {
 819                                printf("%s%s", line_prefix, c_old);
 820                                for (j = 0; j < num_parent; j++) {
 821                                        if (ll->parent_map & (1UL<<j))
 822                                                putchar('-');
 823                                        else
 824                                                putchar(' ');
 825                                }
 826                                show_line_to_eol(ll->line, -1, c_reset);
 827                                ll = ll->next;
 828                        }
 829                        if (cnt < lno)
 830                                break;
 831                        p_mask = 1;
 832                        fputs(line_prefix, stdout);
 833                        if (!(sl->flag & (mark-1))) {
 834                                /*
 835                                 * This sline was here to hang the
 836                                 * lost lines in front of it.
 837                                 */
 838                                if (!context)
 839                                        continue;
 840                                fputs(c_context, stdout);
 841                        }
 842                        else
 843                                fputs(c_new, stdout);
 844                        for (j = 0; j < num_parent; j++) {
 845                                if (p_mask & sl->flag)
 846                                        putchar('+');
 847                                else
 848                                        putchar(' ');
 849                                p_mask <<= 1;
 850                        }
 851                        show_line_to_eol(sl->bol, sl->len, c_reset);
 852                }
 853        }
 854}
 855
 856static void reuse_combine_diff(struct sline *sline, unsigned long cnt,
 857                               int i, int j)
 858{
 859        /* We have already examined parent j and we know parent i
 860         * and parent j are the same, so reuse the combined result
 861         * of parent j for parent i.
 862         */
 863        unsigned long lno, imask, jmask;
 864        imask = (1UL<<i);
 865        jmask = (1UL<<j);
 866
 867        for (lno = 0; lno <= cnt; lno++) {
 868                struct lline *ll = sline->lost;
 869                sline->p_lno[i] = sline->p_lno[j];
 870                while (ll) {
 871                        if (ll->parent_map & jmask)
 872                                ll->parent_map |= imask;
 873                        ll = ll->next;
 874                }
 875                if (sline->flag & jmask)
 876                        sline->flag |= imask;
 877                sline++;
 878        }
 879        /* the overall size of the file (sline[cnt]) */
 880        sline->p_lno[i] = sline->p_lno[j];
 881}
 882
 883static void dump_quoted_path(const char *head,
 884                             const char *prefix,
 885                             const char *path,
 886                             const char *line_prefix,
 887                             const char *c_meta, const char *c_reset)
 888{
 889        static struct strbuf buf = STRBUF_INIT;
 890
 891        strbuf_reset(&buf);
 892        strbuf_addstr(&buf, line_prefix);
 893        strbuf_addstr(&buf, c_meta);
 894        strbuf_addstr(&buf, head);
 895        quote_two_c_style(&buf, prefix, path, 0);
 896        strbuf_addstr(&buf, c_reset);
 897        puts(buf.buf);
 898}
 899
 900static void show_combined_header(struct combine_diff_path *elem,
 901                                 int num_parent,
 902                                 int dense,
 903                                 struct rev_info *rev,
 904                                 const char *line_prefix,
 905                                 int mode_differs,
 906                                 int show_file_header)
 907{
 908        struct diff_options *opt = &rev->diffopt;
 909        int abbrev = opt->flags.full_index ? GIT_SHA1_HEXSZ : DEFAULT_ABBREV;
 910        const char *a_prefix = opt->a_prefix ? opt->a_prefix : "a/";
 911        const char *b_prefix = opt->b_prefix ? opt->b_prefix : "b/";
 912        const char *c_meta = diff_get_color_opt(opt, DIFF_METAINFO);
 913        const char *c_reset = diff_get_color_opt(opt, DIFF_RESET);
 914        const char *abb;
 915        int added = 0;
 916        int deleted = 0;
 917        int i;
 918
 919        if (rev->loginfo && !rev->no_commit_id)
 920                show_log(rev);
 921
 922        dump_quoted_path(dense ? "diff --cc " : "diff --combined ",
 923                         "", elem->path, line_prefix, c_meta, c_reset);
 924        printf("%s%sindex ", line_prefix, c_meta);
 925        for (i = 0; i < num_parent; i++) {
 926                abb = find_unique_abbrev(&elem->parent[i].oid,
 927                                         abbrev);
 928                printf("%s%s", i ? "," : "", abb);
 929        }
 930        abb = find_unique_abbrev(&elem->oid, abbrev);
 931        printf("..%s%s\n", abb, c_reset);
 932
 933        if (mode_differs) {
 934                deleted = !elem->mode;
 935
 936                /* We say it was added if nobody had it */
 937                added = !deleted;
 938                for (i = 0; added && i < num_parent; i++)
 939                        if (elem->parent[i].status !=
 940                            DIFF_STATUS_ADDED)
 941                                added = 0;
 942                if (added)
 943                        printf("%s%snew file mode %06o",
 944                               line_prefix, c_meta, elem->mode);
 945                else {
 946                        if (deleted)
 947                                printf("%s%sdeleted file ",
 948                                       line_prefix, c_meta);
 949                        printf("mode ");
 950                        for (i = 0; i < num_parent; i++) {
 951                                printf("%s%06o", i ? "," : "",
 952                                       elem->parent[i].mode);
 953                        }
 954                        if (elem->mode)
 955                                printf("..%06o", elem->mode);
 956                }
 957                printf("%s\n", c_reset);
 958        }
 959
 960        if (!show_file_header)
 961                return;
 962
 963        if (added)
 964                dump_quoted_path("--- ", "", "/dev/null",
 965                                 line_prefix, c_meta, c_reset);
 966        else
 967                dump_quoted_path("--- ", a_prefix, elem->path,
 968                                 line_prefix, c_meta, c_reset);
 969        if (deleted)
 970                dump_quoted_path("+++ ", "", "/dev/null",
 971                                 line_prefix, c_meta, c_reset);
 972        else
 973                dump_quoted_path("+++ ", b_prefix, elem->path,
 974                                 line_prefix, c_meta, c_reset);
 975}
 976
 977static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 978                            int dense, int working_tree_file,
 979                            struct rev_info *rev)
 980{
 981        struct diff_options *opt = &rev->diffopt;
 982        unsigned long result_size, cnt, lno;
 983        int result_deleted = 0;
 984        char *result, *cp;
 985        struct sline *sline; /* survived lines */
 986        int mode_differs = 0;
 987        int i, show_hunks;
 988        mmfile_t result_file;
 989        struct userdiff_driver *userdiff;
 990        struct userdiff_driver *textconv = NULL;
 991        int is_binary;
 992        const char *line_prefix = diff_line_prefix(opt);
 993
 994        context = opt->context;
 995        userdiff = userdiff_find_by_path(opt->repo->index, elem->path);
 996        if (!userdiff)
 997                userdiff = userdiff_find_by_name("default");
 998        if (opt->flags.allow_textconv)
 999                textconv = userdiff_get_textconv(opt->repo, userdiff);
1000
1001        /* Read the result of merge first */
1002        if (!working_tree_file)
1003                result = grab_blob(opt->repo, &elem->oid, elem->mode, &result_size,
1004                                   textconv, elem->path);
1005        else {
1006                /* Used by diff-tree to read from the working tree */
1007                struct stat st;
1008                int fd = -1;
1009
1010                if (lstat(elem->path, &st) < 0)
1011                        goto deleted_file;
1012
1013                if (S_ISLNK(st.st_mode)) {
1014                        struct strbuf buf = STRBUF_INIT;
1015
1016                        if (strbuf_readlink(&buf, elem->path, st.st_size) < 0) {
1017                                error_errno("readlink(%s)", elem->path);
1018                                return;
1019                        }
1020                        result_size = buf.len;
1021                        result = strbuf_detach(&buf, NULL);
1022                        elem->mode = canon_mode(st.st_mode);
1023                } else if (S_ISDIR(st.st_mode)) {
1024                        struct object_id oid;
1025                        if (resolve_gitlink_ref(elem->path, "HEAD", &oid) < 0)
1026                                result = grab_blob(opt->repo, &elem->oid,
1027                                                   elem->mode, &result_size,
1028                                                   NULL, NULL);
1029                        else
1030                                result = grab_blob(opt->repo, &oid, elem->mode,
1031                                                   &result_size, NULL, NULL);
1032                } else if (textconv) {
1033                        struct diff_filespec *df = alloc_filespec(elem->path);
1034                        fill_filespec(df, &null_oid, 0, st.st_mode);
1035                        result_size = fill_textconv(opt->repo, textconv, df, &result);
1036                        free_filespec(df);
1037                } else if (0 <= (fd = open(elem->path, O_RDONLY))) {
1038                        size_t len = xsize_t(st.st_size);
1039                        ssize_t done;
1040                        int is_file, i;
1041
1042                        elem->mode = canon_mode(st.st_mode);
1043                        /* if symlinks don't work, assume symlink if all parents
1044                         * are symlinks
1045                         */
1046                        is_file = has_symlinks;
1047                        for (i = 0; !is_file && i < num_parent; i++)
1048                                is_file = !S_ISLNK(elem->parent[i].mode);
1049                        if (!is_file)
1050                                elem->mode = canon_mode(S_IFLNK);
1051
1052                        result_size = len;
1053                        result = xmallocz(len);
1054
1055                        done = read_in_full(fd, result, len);
1056                        if (done < 0)
1057                                die_errno("read error '%s'", elem->path);
1058                        else if (done < len)
1059                                die("early EOF '%s'", elem->path);
1060
1061                        /* If not a fake symlink, apply filters, e.g. autocrlf */
1062                        if (is_file) {
1063                                struct strbuf buf = STRBUF_INIT;
1064
1065                                if (convert_to_git(rev->diffopt.repo->index,
1066                                                   elem->path, result, len, &buf, global_conv_flags_eol)) {
1067                                        free(result);
1068                                        result = strbuf_detach(&buf, &len);
1069                                        result_size = len;
1070                                }
1071                        }
1072                }
1073                else {
1074                deleted_file:
1075                        result_deleted = 1;
1076                        result_size = 0;
1077                        elem->mode = 0;
1078                        result = xcalloc(1, 1);
1079                }
1080
1081                if (0 <= fd)
1082                        close(fd);
1083        }
1084
1085        for (i = 0; i < num_parent; i++) {
1086                if (elem->parent[i].mode != elem->mode) {
1087                        mode_differs = 1;
1088                        break;
1089                }
1090        }
1091
1092        if (textconv)
1093                is_binary = 0;
1094        else if (userdiff->binary != -1)
1095                is_binary = userdiff->binary;
1096        else {
1097                is_binary = buffer_is_binary(result, result_size);
1098                for (i = 0; !is_binary && i < num_parent; i++) {
1099                        char *buf;
1100                        unsigned long size;
1101                        buf = grab_blob(opt->repo,
1102                                        &elem->parent[i].oid,
1103                                        elem->parent[i].mode,
1104                                        &size, NULL, NULL);
1105                        if (buffer_is_binary(buf, size))
1106                                is_binary = 1;
1107                        free(buf);
1108                }
1109        }
1110        if (is_binary) {
1111                show_combined_header(elem, num_parent, dense, rev,
1112                                     line_prefix, mode_differs, 0);
1113                printf("Binary files differ\n");
1114                free(result);
1115                return;
1116        }
1117
1118        for (cnt = 0, cp = result; cp < result + result_size; cp++) {
1119                if (*cp == '\n')
1120                        cnt++;
1121        }
1122        if (result_size && result[result_size-1] != '\n')
1123                cnt++; /* incomplete line */
1124
1125        sline = xcalloc(st_add(cnt, 2), sizeof(*sline));
1126        sline[0].bol = result;
1127        for (lno = 0, cp = result; cp < result + result_size; cp++) {
1128                if (*cp == '\n') {
1129                        sline[lno].len = cp - sline[lno].bol;
1130                        lno++;
1131                        if (lno < cnt)
1132                                sline[lno].bol = cp + 1;
1133                }
1134        }
1135        if (result_size && result[result_size-1] != '\n')
1136                sline[cnt-1].len = result_size - (sline[cnt-1].bol - result);
1137
1138        result_file.ptr = result;
1139        result_file.size = result_size;
1140
1141        /* Even p_lno[cnt+1] is valid -- that is for the end line number
1142         * for deletion hunk at the end.
1143         */
1144        sline[0].p_lno = xcalloc(st_mult(st_add(cnt, 2), num_parent), sizeof(unsigned long));
1145        for (lno = 0; lno <= cnt; lno++)
1146                sline[lno+1].p_lno = sline[lno].p_lno + num_parent;
1147
1148        for (i = 0; i < num_parent; i++) {
1149                int j;
1150                for (j = 0; j < i; j++) {
1151                        if (oideq(&elem->parent[i].oid,
1152                                  &elem->parent[j].oid)) {
1153                                reuse_combine_diff(sline, cnt, i, j);
1154                                break;
1155                        }
1156                }
1157                if (i <= j)
1158                        combine_diff(opt->repo,
1159                                     &elem->parent[i].oid,
1160                                     elem->parent[i].mode,
1161                                     &result_file, sline,
1162                                     cnt, i, num_parent, result_deleted,
1163                                     textconv, elem->path, opt->xdl_opts);
1164        }
1165
1166        show_hunks = make_hunks(sline, cnt, num_parent, dense);
1167
1168        if (show_hunks || mode_differs || working_tree_file) {
1169                show_combined_header(elem, num_parent, dense, rev,
1170                                     line_prefix, mode_differs, 1);
1171                dump_sline(sline, line_prefix, cnt, num_parent,
1172                           opt->use_color, result_deleted);
1173        }
1174        free(result);
1175
1176        for (lno = 0; lno < cnt; lno++) {
1177                if (sline[lno].lost) {
1178                        struct lline *ll = sline[lno].lost;
1179                        while (ll) {
1180                                struct lline *tmp = ll;
1181                                ll = ll->next;
1182                                free(tmp);
1183                        }
1184                }
1185        }
1186        free(sline[0].p_lno);
1187        free(sline);
1188}
1189
1190static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct rev_info *rev)
1191{
1192        struct diff_options *opt = &rev->diffopt;
1193        int line_termination, inter_name_termination, i;
1194        const char *line_prefix = diff_line_prefix(opt);
1195
1196        line_termination = opt->line_termination;
1197        inter_name_termination = '\t';
1198        if (!line_termination)
1199                inter_name_termination = 0;
1200
1201        if (rev->loginfo && !rev->no_commit_id)
1202                show_log(rev);
1203
1204
1205        if (opt->output_format & DIFF_FORMAT_RAW) {
1206                printf("%s", line_prefix);
1207
1208                /* As many colons as there are parents */
1209                for (i = 0; i < num_parent; i++)
1210                        putchar(':');
1211
1212                /* Show the modes */
1213                for (i = 0; i < num_parent; i++)
1214                        printf("%06o ", p->parent[i].mode);
1215                printf("%06o", p->mode);
1216
1217                /* Show sha1's */
1218                for (i = 0; i < num_parent; i++)
1219                        printf(" %s", diff_aligned_abbrev(&p->parent[i].oid,
1220                                                          opt->abbrev));
1221                printf(" %s ", diff_aligned_abbrev(&p->oid, opt->abbrev));
1222        }
1223
1224        if (opt->output_format & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS)) {
1225                for (i = 0; i < num_parent; i++)
1226                        putchar(p->parent[i].status);
1227                putchar(inter_name_termination);
1228        }
1229
1230        write_name_quoted(p->path, stdout, line_termination);
1231}
1232
1233/*
1234 * The result (p->elem) is from the working tree and their
1235 * parents are typically from multiple stages during a merge
1236 * (i.e. diff-files) or the state in HEAD and in the index
1237 * (i.e. diff-index).
1238 */
1239void show_combined_diff(struct combine_diff_path *p,
1240                       int num_parent,
1241                       int dense,
1242                       struct rev_info *rev)
1243{
1244        struct diff_options *opt = &rev->diffopt;
1245
1246        if (opt->output_format & (DIFF_FORMAT_RAW |
1247                                  DIFF_FORMAT_NAME |
1248                                  DIFF_FORMAT_NAME_STATUS))
1249                show_raw_diff(p, num_parent, rev);
1250        else if (opt->output_format & DIFF_FORMAT_PATCH)
1251                show_patch_diff(p, num_parent, dense, 1, rev);
1252}
1253
1254static void free_combined_pair(struct diff_filepair *pair)
1255{
1256        free(pair->two);
1257        free(pair);
1258}
1259
1260/*
1261 * A combine_diff_path expresses N parents on the LHS against 1 merge
1262 * result. Synthesize a diff_filepair that has N entries on the "one"
1263 * side and 1 entry on the "two" side.
1264 *
1265 * In the future, we might want to add more data to combine_diff_path
1266 * so that we can fill fields we are ignoring (most notably, size) here,
1267 * but currently nobody uses it, so this should suffice for now.
1268 */
1269static struct diff_filepair *combined_pair(struct combine_diff_path *p,
1270                                           int num_parent)
1271{
1272        int i;
1273        struct diff_filepair *pair;
1274        struct diff_filespec *pool;
1275
1276        pair = xmalloc(sizeof(*pair));
1277        pool = xcalloc(st_add(num_parent, 1), sizeof(struct diff_filespec));
1278        pair->one = pool + 1;
1279        pair->two = pool;
1280
1281        for (i = 0; i < num_parent; i++) {
1282                pair->one[i].path = p->path;
1283                pair->one[i].mode = p->parent[i].mode;
1284                oidcpy(&pair->one[i].oid, &p->parent[i].oid);
1285                pair->one[i].oid_valid = !is_null_oid(&p->parent[i].oid);
1286                pair->one[i].has_more_entries = 1;
1287        }
1288        pair->one[num_parent - 1].has_more_entries = 0;
1289
1290        pair->two->path = p->path;
1291        pair->two->mode = p->mode;
1292        oidcpy(&pair->two->oid, &p->oid);
1293        pair->two->oid_valid = !is_null_oid(&p->oid);
1294        return pair;
1295}
1296
1297static void handle_combined_callback(struct diff_options *opt,
1298                                     struct combine_diff_path *paths,
1299                                     int num_parent,
1300                                     int num_paths)
1301{
1302        struct combine_diff_path *p;
1303        struct diff_queue_struct q;
1304        int i;
1305
1306        q.queue = xcalloc(num_paths, sizeof(struct diff_filepair *));
1307        q.alloc = num_paths;
1308        q.nr = num_paths;
1309        for (i = 0, p = paths; p; p = p->next)
1310                q.queue[i++] = combined_pair(p, num_parent);
1311        opt->format_callback(&q, opt, opt->format_callback_data);
1312        for (i = 0; i < num_paths; i++)
1313                free_combined_pair(q.queue[i]);
1314        free(q.queue);
1315}
1316
1317static const char *path_path(void *obj)
1318{
1319        struct combine_diff_path *path = (struct combine_diff_path *)obj;
1320
1321        return path->path;
1322}
1323
1324
1325/* find set of paths that every parent touches */
1326static struct combine_diff_path *find_paths_generic(const struct object_id *oid,
1327        const struct oid_array *parents, struct diff_options *opt)
1328{
1329        struct combine_diff_path *paths = NULL;
1330        int i, num_parent = parents->nr;
1331
1332        int output_format = opt->output_format;
1333        const char *orderfile = opt->orderfile;
1334
1335        opt->output_format = DIFF_FORMAT_NO_OUTPUT;
1336        /* tell diff_tree to emit paths in sorted (=tree) order */
1337        opt->orderfile = NULL;
1338
1339        /* D(A,P1...Pn) = D(A,P1) ^ ... ^ D(A,Pn)  (wrt paths) */
1340        for (i = 0; i < num_parent; i++) {
1341                /*
1342                 * show stat against the first parent even when doing
1343                 * combined diff.
1344                 */
1345                int stat_opt = (output_format &
1346                                (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
1347                if (i == 0 && stat_opt)
1348                        opt->output_format = stat_opt;
1349                else
1350                        opt->output_format = DIFF_FORMAT_NO_OUTPUT;
1351                diff_tree_oid(&parents->oid[i], oid, "", opt);
1352                diffcore_std(opt);
1353                paths = intersect_paths(paths, i, num_parent);
1354
1355                /* if showing diff, show it in requested order */
1356                if (opt->output_format != DIFF_FORMAT_NO_OUTPUT &&
1357                    orderfile) {
1358                        diffcore_order(orderfile);
1359                }
1360
1361                diff_flush(opt);
1362        }
1363
1364        opt->output_format = output_format;
1365        opt->orderfile = orderfile;
1366        return paths;
1367}
1368
1369
1370/*
1371 * find set of paths that everybody touches, assuming diff is run without
1372 * rename/copy detection, etc, comparing all trees simultaneously (= faster).
1373 */
1374static struct combine_diff_path *find_paths_multitree(
1375        const struct object_id *oid, const struct oid_array *parents,
1376        struct diff_options *opt)
1377{
1378        int i, nparent = parents->nr;
1379        const struct object_id **parents_oid;
1380        struct combine_diff_path paths_head;
1381        struct strbuf base;
1382
1383        ALLOC_ARRAY(parents_oid, nparent);
1384        for (i = 0; i < nparent; i++)
1385                parents_oid[i] = &parents->oid[i];
1386
1387        /* fake list head, so worker can assume it is non-NULL */
1388        paths_head.next = NULL;
1389
1390        strbuf_init(&base, PATH_MAX);
1391        diff_tree_paths(&paths_head, oid, parents_oid, nparent, &base, opt);
1392
1393        strbuf_release(&base);
1394        free(parents_oid);
1395        return paths_head.next;
1396}
1397
1398
1399void diff_tree_combined(const struct object_id *oid,
1400                        const struct oid_array *parents,
1401                        int dense,
1402                        struct rev_info *rev)
1403{
1404        struct diff_options *opt = &rev->diffopt;
1405        struct diff_options diffopts;
1406        struct combine_diff_path *p, *paths;
1407        int i, num_paths, needsep, show_log_first, num_parent = parents->nr;
1408        int need_generic_pathscan;
1409
1410        /* nothing to do, if no parents */
1411        if (!num_parent)
1412                return;
1413
1414        show_log_first = !!rev->loginfo && !rev->no_commit_id;
1415        needsep = 0;
1416        if (show_log_first) {
1417                show_log(rev);
1418
1419                if (rev->verbose_header && opt->output_format &&
1420                    opt->output_format != DIFF_FORMAT_NO_OUTPUT &&
1421                    !commit_format_is_empty(rev->commit_format))
1422                        printf("%s%c", diff_line_prefix(opt),
1423                               opt->line_termination);
1424        }
1425
1426        diffopts = *opt;
1427        copy_pathspec(&diffopts.pathspec, &opt->pathspec);
1428        diffopts.flags.recursive = 1;
1429        diffopts.flags.allow_external = 0;
1430
1431        /* find set of paths that everybody touches
1432         *
1433         * NOTE
1434         *
1435         * Diffcore transformations are bound to diff_filespec and logic
1436         * comparing two entries - i.e. they do not apply directly to combine
1437         * diff.
1438         *
1439         * If some of such transformations is requested - we launch generic
1440         * path scanning, which works significantly slower compared to
1441         * simultaneous all-trees-in-one-go scan in find_paths_multitree().
1442         *
1443         * TODO some of the filters could be ported to work on
1444         * combine_diff_paths - i.e. all functionality that skips paths, so in
1445         * theory, we could end up having only multitree path scanning.
1446         *
1447         * NOTE please keep this semantically in sync with diffcore_std()
1448         */
1449        need_generic_pathscan = opt->skip_stat_unmatch  ||
1450                        opt->flags.follow_renames       ||
1451                        opt->break_opt != -1    ||
1452                        opt->detect_rename      ||
1453                        (opt->pickaxe_opts & DIFF_PICKAXE_KINDS_MASK)   ||
1454                        opt->filter;
1455
1456
1457        if (need_generic_pathscan) {
1458                /*
1459                 * NOTE generic case also handles --stat, as it computes
1460                 * diff(sha1,parent_i) for all i to do the job, specifically
1461                 * for parent0.
1462                 */
1463                paths = find_paths_generic(oid, parents, &diffopts);
1464        }
1465        else {
1466                int stat_opt;
1467                paths = find_paths_multitree(oid, parents, &diffopts);
1468
1469                /*
1470                 * show stat against the first parent even
1471                 * when doing combined diff.
1472                 */
1473                stat_opt = (opt->output_format &
1474                                (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT));
1475                if (stat_opt) {
1476                        diffopts.output_format = stat_opt;
1477
1478                        diff_tree_oid(&parents->oid[0], oid, "", &diffopts);
1479                        diffcore_std(&diffopts);
1480                        if (opt->orderfile)
1481                                diffcore_order(opt->orderfile);
1482                        diff_flush(&diffopts);
1483                }
1484        }
1485
1486        /* find out number of surviving paths */
1487        for (num_paths = 0, p = paths; p; p = p->next)
1488                num_paths++;
1489
1490        /* order paths according to diffcore_order */
1491        if (opt->orderfile && num_paths) {
1492                struct obj_order *o;
1493
1494                ALLOC_ARRAY(o, num_paths);
1495                for (i = 0, p = paths; p; p = p->next, i++)
1496                        o[i].obj = p;
1497                order_objects(opt->orderfile, path_path, o, num_paths);
1498                for (i = 0; i < num_paths - 1; i++) {
1499                        p = o[i].obj;
1500                        p->next = o[i+1].obj;
1501                }
1502
1503                p = o[num_paths-1].obj;
1504                p->next = NULL;
1505                paths = o[0].obj;
1506                free(o);
1507        }
1508
1509
1510        if (num_paths) {
1511                if (opt->output_format & (DIFF_FORMAT_RAW |
1512                                          DIFF_FORMAT_NAME |
1513                                          DIFF_FORMAT_NAME_STATUS)) {
1514                        for (p = paths; p; p = p->next)
1515                                show_raw_diff(p, num_parent, rev);
1516                        needsep = 1;
1517                }
1518                else if (opt->output_format &
1519                         (DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIFFSTAT))
1520                        needsep = 1;
1521                else if (opt->output_format & DIFF_FORMAT_CALLBACK)
1522                        handle_combined_callback(opt, paths, num_parent, num_paths);
1523
1524                if (opt->output_format & DIFF_FORMAT_PATCH) {
1525                        if (needsep)
1526                                printf("%s%c", diff_line_prefix(opt),
1527                                       opt->line_termination);
1528                        for (p = paths; p; p = p->next)
1529                                show_patch_diff(p, num_parent, dense,
1530                                                0, rev);
1531                }
1532        }
1533
1534        /* Clean things up */
1535        while (paths) {
1536                struct combine_diff_path *tmp = paths;
1537                paths = paths->next;
1538                free(tmp);
1539        }
1540
1541        clear_pathspec(&diffopts.pathspec);
1542}
1543
1544void diff_tree_combined_merge(const struct commit *commit, int dense,
1545                              struct rev_info *rev)
1546{
1547        struct commit_list *parent = get_saved_parents(rev, commit);
1548        struct oid_array parents = OID_ARRAY_INIT;
1549
1550        while (parent) {
1551                oid_array_append(&parents, &parent->item->object.oid);
1552                parent = parent->next;
1553        }
1554        diff_tree_combined(&commit->object.oid, &parents, dense, rev);
1555        oid_array_clear(&parents);
1556}