builtin / blame.con commit Merge branch 'ap/merge-stop-at-prepare-commit-msg-failure' (ea12a7d)
   1/*
   2 * Blame
   3 *
   4 * Copyright (c) 2006, Junio C Hamano
   5 */
   6
   7#include "cache.h"
   8#include "builtin.h"
   9#include "blob.h"
  10#include "commit.h"
  11#include "tag.h"
  12#include "tree-walk.h"
  13#include "diff.h"
  14#include "diffcore.h"
  15#include "revision.h"
  16#include "quote.h"
  17#include "xdiff-interface.h"
  18#include "cache-tree.h"
  19#include "string-list.h"
  20#include "mailmap.h"
  21#include "parse-options.h"
  22#include "utf8.h"
  23#include "userdiff.h"
  24
  25static char blame_usage[] = N_("git blame [options] [rev-opts] [rev] [--] file");
  26
  27static const char *blame_opt_usage[] = {
  28        blame_usage,
  29        "",
  30        N_("[rev-opts] are documented in git-rev-list(1)"),
  31        NULL
  32};
  33
  34static int longest_file;
  35static int longest_author;
  36static int max_orig_digits;
  37static int max_digits;
  38static int max_score_digits;
  39static int show_root;
  40static int reverse;
  41static int blank_boundary;
  42static int incremental;
  43static int xdl_opts;
  44static int abbrev = -1;
  45
  46static enum date_mode blame_date_mode = DATE_ISO8601;
  47static size_t blame_date_width;
  48
  49static struct string_list mailmap;
  50
  51#ifndef DEBUG
  52#define DEBUG 0
  53#endif
  54
  55/* stats */
  56static int num_read_blob;
  57static int num_get_patch;
  58static int num_commits;
  59
  60#define PICKAXE_BLAME_MOVE              01
  61#define PICKAXE_BLAME_COPY              02
  62#define PICKAXE_BLAME_COPY_HARDER       04
  63#define PICKAXE_BLAME_COPY_HARDEST      010
  64
  65/*
  66 * blame for a blame_entry with score lower than these thresholds
  67 * is not passed to the parent using move/copy logic.
  68 */
  69static unsigned blame_move_score;
  70static unsigned blame_copy_score;
  71#define BLAME_DEFAULT_MOVE_SCORE        20
  72#define BLAME_DEFAULT_COPY_SCORE        40
  73
  74/* bits #0..7 in revision.h, #8..11 used for merge_bases() in commit.c */
  75#define METAINFO_SHOWN          (1u<<12)
  76#define MORE_THAN_ONE_PATH      (1u<<13)
  77
  78/*
  79 * One blob in a commit that is being suspected
  80 */
  81struct origin {
  82        int refcnt;
  83        struct origin *previous;
  84        struct commit *commit;
  85        mmfile_t file;
  86        unsigned char blob_sha1[20];
  87        unsigned mode;
  88        char path[FLEX_ARRAY];
  89};
  90
  91static int diff_hunks(mmfile_t *file_a, mmfile_t *file_b, long ctxlen,
  92                      xdl_emit_hunk_consume_func_t hunk_func, void *cb_data)
  93{
  94        xpparam_t xpp = {0};
  95        xdemitconf_t xecfg = {0};
  96        xdemitcb_t ecb = {NULL};
  97
  98        xpp.flags = xdl_opts;
  99        xecfg.ctxlen = ctxlen;
 100        xecfg.hunk_func = hunk_func;
 101        ecb.priv = cb_data;
 102        return xdi_diff(file_a, file_b, &xpp, &xecfg, &ecb);
 103}
 104
 105/*
 106 * Prepare diff_filespec and convert it using diff textconv API
 107 * if the textconv driver exists.
 108 * Return 1 if the conversion succeeds, 0 otherwise.
 109 */
 110int textconv_object(const char *path,
 111                    unsigned mode,
 112                    const unsigned char *sha1,
 113                    int sha1_valid,
 114                    char **buf,
 115                    unsigned long *buf_size)
 116{
 117        struct diff_filespec *df;
 118        struct userdiff_driver *textconv;
 119
 120        df = alloc_filespec(path);
 121        fill_filespec(df, sha1, sha1_valid, mode);
 122        textconv = get_textconv(df);
 123        if (!textconv) {
 124                free_filespec(df);
 125                return 0;
 126        }
 127
 128        *buf_size = fill_textconv(textconv, df, buf);
 129        free_filespec(df);
 130        return 1;
 131}
 132
 133/*
 134 * Given an origin, prepare mmfile_t structure to be used by the
 135 * diff machinery
 136 */
 137static void fill_origin_blob(struct diff_options *opt,
 138                             struct origin *o, mmfile_t *file)
 139{
 140        if (!o->file.ptr) {
 141                enum object_type type;
 142                unsigned long file_size;
 143
 144                num_read_blob++;
 145                if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
 146                    textconv_object(o->path, o->mode, o->blob_sha1, 1, &file->ptr, &file_size))
 147                        ;
 148                else
 149                        file->ptr = read_sha1_file(o->blob_sha1, &type, &file_size);
 150                file->size = file_size;
 151
 152                if (!file->ptr)
 153                        die("Cannot read blob %s for path %s",
 154                            sha1_to_hex(o->blob_sha1),
 155                            o->path);
 156                o->file = *file;
 157        }
 158        else
 159                *file = o->file;
 160}
 161
 162/*
 163 * Origin is refcounted and usually we keep the blob contents to be
 164 * reused.
 165 */
 166static inline struct origin *origin_incref(struct origin *o)
 167{
 168        if (o)
 169                o->refcnt++;
 170        return o;
 171}
 172
 173static void origin_decref(struct origin *o)
 174{
 175        if (o && --o->refcnt <= 0) {
 176                if (o->previous)
 177                        origin_decref(o->previous);
 178                free(o->file.ptr);
 179                free(o);
 180        }
 181}
 182
 183static void drop_origin_blob(struct origin *o)
 184{
 185        if (o->file.ptr) {
 186                free(o->file.ptr);
 187                o->file.ptr = NULL;
 188        }
 189}
 190
 191/*
 192 * Each group of lines is described by a blame_entry; it can be split
 193 * as we pass blame to the parents.  They form a linked list in the
 194 * scoreboard structure, sorted by the target line number.
 195 */
 196struct blame_entry {
 197        struct blame_entry *prev;
 198        struct blame_entry *next;
 199
 200        /* the first line of this group in the final image;
 201         * internally all line numbers are 0 based.
 202         */
 203        int lno;
 204
 205        /* how many lines this group has */
 206        int num_lines;
 207
 208        /* the commit that introduced this group into the final image */
 209        struct origin *suspect;
 210
 211        /* true if the suspect is truly guilty; false while we have not
 212         * checked if the group came from one of its parents.
 213         */
 214        char guilty;
 215
 216        /* true if the entry has been scanned for copies in the current parent
 217         */
 218        char scanned;
 219
 220        /* the line number of the first line of this group in the
 221         * suspect's file; internally all line numbers are 0 based.
 222         */
 223        int s_lno;
 224
 225        /* how significant this entry is -- cached to avoid
 226         * scanning the lines over and over.
 227         */
 228        unsigned score;
 229};
 230
 231/*
 232 * The current state of the blame assignment.
 233 */
 234struct scoreboard {
 235        /* the final commit (i.e. where we started digging from) */
 236        struct commit *final;
 237        struct rev_info *revs;
 238        const char *path;
 239
 240        /*
 241         * The contents in the final image.
 242         * Used by many functions to obtain contents of the nth line,
 243         * indexed with scoreboard.lineno[blame_entry.lno].
 244         */
 245        const char *final_buf;
 246        unsigned long final_buf_size;
 247
 248        /* linked list of blames */
 249        struct blame_entry *ent;
 250
 251        /* look-up a line in the final buffer */
 252        int num_lines;
 253        int *lineno;
 254};
 255
 256static inline int same_suspect(struct origin *a, struct origin *b)
 257{
 258        if (a == b)
 259                return 1;
 260        if (a->commit != b->commit)
 261                return 0;
 262        return !strcmp(a->path, b->path);
 263}
 264
 265static void sanity_check_refcnt(struct scoreboard *);
 266
 267/*
 268 * If two blame entries that are next to each other came from
 269 * contiguous lines in the same origin (i.e. <commit, path> pair),
 270 * merge them together.
 271 */
 272static void coalesce(struct scoreboard *sb)
 273{
 274        struct blame_entry *ent, *next;
 275
 276        for (ent = sb->ent; ent && (next = ent->next); ent = next) {
 277                if (same_suspect(ent->suspect, next->suspect) &&
 278                    ent->guilty == next->guilty &&
 279                    ent->s_lno + ent->num_lines == next->s_lno) {
 280                        ent->num_lines += next->num_lines;
 281                        ent->next = next->next;
 282                        if (ent->next)
 283                                ent->next->prev = ent;
 284                        origin_decref(next->suspect);
 285                        free(next);
 286                        ent->score = 0;
 287                        next = ent; /* again */
 288                }
 289        }
 290
 291        if (DEBUG) /* sanity */
 292                sanity_check_refcnt(sb);
 293}
 294
 295/*
 296 * Given a commit and a path in it, create a new origin structure.
 297 * The callers that add blame to the scoreboard should use
 298 * get_origin() to obtain shared, refcounted copy instead of calling
 299 * this function directly.
 300 */
 301static struct origin *make_origin(struct commit *commit, const char *path)
 302{
 303        struct origin *o;
 304        o = xcalloc(1, sizeof(*o) + strlen(path) + 1);
 305        o->commit = commit;
 306        o->refcnt = 1;
 307        strcpy(o->path, path);
 308        return o;
 309}
 310
 311/*
 312 * Locate an existing origin or create a new one.
 313 */
 314static struct origin *get_origin(struct scoreboard *sb,
 315                                 struct commit *commit,
 316                                 const char *path)
 317{
 318        struct blame_entry *e;
 319
 320        for (e = sb->ent; e; e = e->next) {
 321                if (e->suspect->commit == commit &&
 322                    !strcmp(e->suspect->path, path))
 323                        return origin_incref(e->suspect);
 324        }
 325        return make_origin(commit, path);
 326}
 327
 328/*
 329 * Fill the blob_sha1 field of an origin if it hasn't, so that later
 330 * call to fill_origin_blob() can use it to locate the data.  blob_sha1
 331 * for an origin is also used to pass the blame for the entire file to
 332 * the parent to detect the case where a child's blob is identical to
 333 * that of its parent's.
 334 *
 335 * This also fills origin->mode for corresponding tree path.
 336 */
 337static int fill_blob_sha1_and_mode(struct origin *origin)
 338{
 339        if (!is_null_sha1(origin->blob_sha1))
 340                return 0;
 341        if (get_tree_entry(origin->commit->object.sha1,
 342                           origin->path,
 343                           origin->blob_sha1, &origin->mode))
 344                goto error_out;
 345        if (sha1_object_info(origin->blob_sha1, NULL) != OBJ_BLOB)
 346                goto error_out;
 347        return 0;
 348 error_out:
 349        hashclr(origin->blob_sha1);
 350        origin->mode = S_IFINVALID;
 351        return -1;
 352}
 353
 354/*
 355 * We have an origin -- check if the same path exists in the
 356 * parent and return an origin structure to represent it.
 357 */
 358static struct origin *find_origin(struct scoreboard *sb,
 359                                  struct commit *parent,
 360                                  struct origin *origin)
 361{
 362        struct origin *porigin = NULL;
 363        struct diff_options diff_opts;
 364        const char *paths[2];
 365
 366        if (parent->util) {
 367                /*
 368                 * Each commit object can cache one origin in that
 369                 * commit.  This is a freestanding copy of origin and
 370                 * not refcounted.
 371                 */
 372                struct origin *cached = parent->util;
 373                if (!strcmp(cached->path, origin->path)) {
 374                        /*
 375                         * The same path between origin and its parent
 376                         * without renaming -- the most common case.
 377                         */
 378                        porigin = get_origin(sb, parent, cached->path);
 379
 380                        /*
 381                         * If the origin was newly created (i.e. get_origin
 382                         * would call make_origin if none is found in the
 383                         * scoreboard), it does not know the blob_sha1/mode,
 384                         * so copy it.  Otherwise porigin was in the
 385                         * scoreboard and already knows blob_sha1/mode.
 386                         */
 387                        if (porigin->refcnt == 1) {
 388                                hashcpy(porigin->blob_sha1, cached->blob_sha1);
 389                                porigin->mode = cached->mode;
 390                        }
 391                        return porigin;
 392                }
 393                /* otherwise it was not very useful; free it */
 394                free(parent->util);
 395                parent->util = NULL;
 396        }
 397
 398        /* See if the origin->path is different between parent
 399         * and origin first.  Most of the time they are the
 400         * same and diff-tree is fairly efficient about this.
 401         */
 402        diff_setup(&diff_opts);
 403        DIFF_OPT_SET(&diff_opts, RECURSIVE);
 404        diff_opts.detect_rename = 0;
 405        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 406        paths[0] = origin->path;
 407        paths[1] = NULL;
 408
 409        diff_tree_setup_paths(paths, &diff_opts);
 410        diff_setup_done(&diff_opts);
 411
 412        if (is_null_sha1(origin->commit->object.sha1))
 413                do_diff_cache(parent->tree->object.sha1, &diff_opts);
 414        else
 415                diff_tree_sha1(parent->tree->object.sha1,
 416                               origin->commit->tree->object.sha1,
 417                               "", &diff_opts);
 418        diffcore_std(&diff_opts);
 419
 420        if (!diff_queued_diff.nr) {
 421                /* The path is the same as parent */
 422                porigin = get_origin(sb, parent, origin->path);
 423                hashcpy(porigin->blob_sha1, origin->blob_sha1);
 424                porigin->mode = origin->mode;
 425        } else {
 426                /*
 427                 * Since origin->path is a pathspec, if the parent
 428                 * commit had it as a directory, we will see a whole
 429                 * bunch of deletion of files in the directory that we
 430                 * do not care about.
 431                 */
 432                int i;
 433                struct diff_filepair *p = NULL;
 434                for (i = 0; i < diff_queued_diff.nr; i++) {
 435                        const char *name;
 436                        p = diff_queued_diff.queue[i];
 437                        name = p->one->path ? p->one->path : p->two->path;
 438                        if (!strcmp(name, origin->path))
 439                                break;
 440                }
 441                if (!p)
 442                        die("internal error in blame::find_origin");
 443                switch (p->status) {
 444                default:
 445                        die("internal error in blame::find_origin (%c)",
 446                            p->status);
 447                case 'M':
 448                        porigin = get_origin(sb, parent, origin->path);
 449                        hashcpy(porigin->blob_sha1, p->one->sha1);
 450                        porigin->mode = p->one->mode;
 451                        break;
 452                case 'A':
 453                case 'T':
 454                        /* Did not exist in parent, or type changed */
 455                        break;
 456                }
 457        }
 458        diff_flush(&diff_opts);
 459        diff_tree_release_paths(&diff_opts);
 460        if (porigin) {
 461                /*
 462                 * Create a freestanding copy that is not part of
 463                 * the refcounted origin found in the scoreboard, and
 464                 * cache it in the commit.
 465                 */
 466                struct origin *cached;
 467
 468                cached = make_origin(porigin->commit, porigin->path);
 469                hashcpy(cached->blob_sha1, porigin->blob_sha1);
 470                cached->mode = porigin->mode;
 471                parent->util = cached;
 472        }
 473        return porigin;
 474}
 475
 476/*
 477 * We have an origin -- find the path that corresponds to it in its
 478 * parent and return an origin structure to represent it.
 479 */
 480static struct origin *find_rename(struct scoreboard *sb,
 481                                  struct commit *parent,
 482                                  struct origin *origin)
 483{
 484        struct origin *porigin = NULL;
 485        struct diff_options diff_opts;
 486        int i;
 487        const char *paths[2];
 488
 489        diff_setup(&diff_opts);
 490        DIFF_OPT_SET(&diff_opts, RECURSIVE);
 491        diff_opts.detect_rename = DIFF_DETECT_RENAME;
 492        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 493        diff_opts.single_follow = origin->path;
 494        paths[0] = NULL;
 495        diff_tree_setup_paths(paths, &diff_opts);
 496        diff_setup_done(&diff_opts);
 497
 498        if (is_null_sha1(origin->commit->object.sha1))
 499                do_diff_cache(parent->tree->object.sha1, &diff_opts);
 500        else
 501                diff_tree_sha1(parent->tree->object.sha1,
 502                               origin->commit->tree->object.sha1,
 503                               "", &diff_opts);
 504        diffcore_std(&diff_opts);
 505
 506        for (i = 0; i < diff_queued_diff.nr; i++) {
 507                struct diff_filepair *p = diff_queued_diff.queue[i];
 508                if ((p->status == 'R' || p->status == 'C') &&
 509                    !strcmp(p->two->path, origin->path)) {
 510                        porigin = get_origin(sb, parent, p->one->path);
 511                        hashcpy(porigin->blob_sha1, p->one->sha1);
 512                        porigin->mode = p->one->mode;
 513                        break;
 514                }
 515        }
 516        diff_flush(&diff_opts);
 517        diff_tree_release_paths(&diff_opts);
 518        return porigin;
 519}
 520
 521/*
 522 * Link in a new blame entry to the scoreboard.  Entries that cover the
 523 * same line range have been removed from the scoreboard previously.
 524 */
 525static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e)
 526{
 527        struct blame_entry *ent, *prev = NULL;
 528
 529        origin_incref(e->suspect);
 530
 531        for (ent = sb->ent; ent && ent->lno < e->lno; ent = ent->next)
 532                prev = ent;
 533
 534        /* prev, if not NULL, is the last one that is below e */
 535        e->prev = prev;
 536        if (prev) {
 537                e->next = prev->next;
 538                prev->next = e;
 539        }
 540        else {
 541                e->next = sb->ent;
 542                sb->ent = e;
 543        }
 544        if (e->next)
 545                e->next->prev = e;
 546}
 547
 548/*
 549 * src typically is on-stack; we want to copy the information in it to
 550 * a malloced blame_entry that is already on the linked list of the
 551 * scoreboard.  The origin of dst loses a refcnt while the origin of src
 552 * gains one.
 553 */
 554static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
 555{
 556        struct blame_entry *p, *n;
 557
 558        p = dst->prev;
 559        n = dst->next;
 560        origin_incref(src->suspect);
 561        origin_decref(dst->suspect);
 562        memcpy(dst, src, sizeof(*src));
 563        dst->prev = p;
 564        dst->next = n;
 565        dst->score = 0;
 566}
 567
 568static const char *nth_line(struct scoreboard *sb, int lno)
 569{
 570        return sb->final_buf + sb->lineno[lno];
 571}
 572
 573/*
 574 * It is known that lines between tlno to same came from parent, and e
 575 * has an overlap with that range.  it also is known that parent's
 576 * line plno corresponds to e's line tlno.
 577 *
 578 *                <---- e ----->
 579 *                   <------>
 580 *                   <------------>
 581 *             <------------>
 582 *             <------------------>
 583 *
 584 * Split e into potentially three parts; before this chunk, the chunk
 585 * to be blamed for the parent, and after that portion.
 586 */
 587static void split_overlap(struct blame_entry *split,
 588                          struct blame_entry *e,
 589                          int tlno, int plno, int same,
 590                          struct origin *parent)
 591{
 592        int chunk_end_lno;
 593        memset(split, 0, sizeof(struct blame_entry [3]));
 594
 595        if (e->s_lno < tlno) {
 596                /* there is a pre-chunk part not blamed on parent */
 597                split[0].suspect = origin_incref(e->suspect);
 598                split[0].lno = e->lno;
 599                split[0].s_lno = e->s_lno;
 600                split[0].num_lines = tlno - e->s_lno;
 601                split[1].lno = e->lno + tlno - e->s_lno;
 602                split[1].s_lno = plno;
 603        }
 604        else {
 605                split[1].lno = e->lno;
 606                split[1].s_lno = plno + (e->s_lno - tlno);
 607        }
 608
 609        if (same < e->s_lno + e->num_lines) {
 610                /* there is a post-chunk part not blamed on parent */
 611                split[2].suspect = origin_incref(e->suspect);
 612                split[2].lno = e->lno + (same - e->s_lno);
 613                split[2].s_lno = e->s_lno + (same - e->s_lno);
 614                split[2].num_lines = e->s_lno + e->num_lines - same;
 615                chunk_end_lno = split[2].lno;
 616        }
 617        else
 618                chunk_end_lno = e->lno + e->num_lines;
 619        split[1].num_lines = chunk_end_lno - split[1].lno;
 620
 621        /*
 622         * if it turns out there is nothing to blame the parent for,
 623         * forget about the splitting.  !split[1].suspect signals this.
 624         */
 625        if (split[1].num_lines < 1)
 626                return;
 627        split[1].suspect = origin_incref(parent);
 628}
 629
 630/*
 631 * split_overlap() divided an existing blame e into up to three parts
 632 * in split.  Adjust the linked list of blames in the scoreboard to
 633 * reflect the split.
 634 */
 635static void split_blame(struct scoreboard *sb,
 636                        struct blame_entry *split,
 637                        struct blame_entry *e)
 638{
 639        struct blame_entry *new_entry;
 640
 641        if (split[0].suspect && split[2].suspect) {
 642                /* The first part (reuse storage for the existing entry e) */
 643                dup_entry(e, &split[0]);
 644
 645                /* The last part -- me */
 646                new_entry = xmalloc(sizeof(*new_entry));
 647                memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 648                add_blame_entry(sb, new_entry);
 649
 650                /* ... and the middle part -- parent */
 651                new_entry = xmalloc(sizeof(*new_entry));
 652                memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 653                add_blame_entry(sb, new_entry);
 654        }
 655        else if (!split[0].suspect && !split[2].suspect)
 656                /*
 657                 * The parent covers the entire area; reuse storage for
 658                 * e and replace it with the parent.
 659                 */
 660                dup_entry(e, &split[1]);
 661        else if (split[0].suspect) {
 662                /* me and then parent */
 663                dup_entry(e, &split[0]);
 664
 665                new_entry = xmalloc(sizeof(*new_entry));
 666                memcpy(new_entry, &(split[1]), sizeof(struct blame_entry));
 667                add_blame_entry(sb, new_entry);
 668        }
 669        else {
 670                /* parent and then me */
 671                dup_entry(e, &split[1]);
 672
 673                new_entry = xmalloc(sizeof(*new_entry));
 674                memcpy(new_entry, &(split[2]), sizeof(struct blame_entry));
 675                add_blame_entry(sb, new_entry);
 676        }
 677
 678        if (DEBUG) { /* sanity */
 679                struct blame_entry *ent;
 680                int lno = sb->ent->lno, corrupt = 0;
 681
 682                for (ent = sb->ent; ent; ent = ent->next) {
 683                        if (lno != ent->lno)
 684                                corrupt = 1;
 685                        if (ent->s_lno < 0)
 686                                corrupt = 1;
 687                        lno += ent->num_lines;
 688                }
 689                if (corrupt) {
 690                        lno = sb->ent->lno;
 691                        for (ent = sb->ent; ent; ent = ent->next) {
 692                                printf("L %8d l %8d n %8d\n",
 693                                       lno, ent->lno, ent->num_lines);
 694                                lno = ent->lno + ent->num_lines;
 695                        }
 696                        die("oops");
 697                }
 698        }
 699}
 700
 701/*
 702 * After splitting the blame, the origins used by the
 703 * on-stack blame_entry should lose one refcnt each.
 704 */
 705static void decref_split(struct blame_entry *split)
 706{
 707        int i;
 708
 709        for (i = 0; i < 3; i++)
 710                origin_decref(split[i].suspect);
 711}
 712
 713/*
 714 * Helper for blame_chunk().  blame_entry e is known to overlap with
 715 * the patch hunk; split it and pass blame to the parent.
 716 */
 717static void blame_overlap(struct scoreboard *sb, struct blame_entry *e,
 718                          int tlno, int plno, int same,
 719                          struct origin *parent)
 720{
 721        struct blame_entry split[3];
 722
 723        split_overlap(split, e, tlno, plno, same, parent);
 724        if (split[1].suspect)
 725                split_blame(sb, split, e);
 726        decref_split(split);
 727}
 728
 729/*
 730 * Find the line number of the last line the target is suspected for.
 731 */
 732static int find_last_in_target(struct scoreboard *sb, struct origin *target)
 733{
 734        struct blame_entry *e;
 735        int last_in_target = -1;
 736
 737        for (e = sb->ent; e; e = e->next) {
 738                if (e->guilty || !same_suspect(e->suspect, target))
 739                        continue;
 740                if (last_in_target < e->s_lno + e->num_lines)
 741                        last_in_target = e->s_lno + e->num_lines;
 742        }
 743        return last_in_target;
 744}
 745
 746/*
 747 * Process one hunk from the patch between the current suspect for
 748 * blame_entry e and its parent.  Find and split the overlap, and
 749 * pass blame to the overlapping part to the parent.
 750 */
 751static void blame_chunk(struct scoreboard *sb,
 752                        int tlno, int plno, int same,
 753                        struct origin *target, struct origin *parent)
 754{
 755        struct blame_entry *e;
 756
 757        for (e = sb->ent; e; e = e->next) {
 758                if (e->guilty || !same_suspect(e->suspect, target))
 759                        continue;
 760                if (same <= e->s_lno)
 761                        continue;
 762                if (tlno < e->s_lno + e->num_lines)
 763                        blame_overlap(sb, e, tlno, plno, same, parent);
 764        }
 765}
 766
 767struct blame_chunk_cb_data {
 768        struct scoreboard *sb;
 769        struct origin *target;
 770        struct origin *parent;
 771        long plno;
 772        long tlno;
 773};
 774
 775static int blame_chunk_cb(long start_a, long count_a,
 776                          long start_b, long count_b, void *data)
 777{
 778        struct blame_chunk_cb_data *d = data;
 779        blame_chunk(d->sb, d->tlno, d->plno, start_b, d->target, d->parent);
 780        d->plno = start_a + count_a;
 781        d->tlno = start_b + count_b;
 782        return 0;
 783}
 784
 785/*
 786 * We are looking at the origin 'target' and aiming to pass blame
 787 * for the lines it is suspected to its parent.  Run diff to find
 788 * which lines came from parent and pass blame for them.
 789 */
 790static int pass_blame_to_parent(struct scoreboard *sb,
 791                                struct origin *target,
 792                                struct origin *parent)
 793{
 794        int last_in_target;
 795        mmfile_t file_p, file_o;
 796        struct blame_chunk_cb_data d;
 797
 798        memset(&d, 0, sizeof(d));
 799        d.sb = sb; d.target = target; d.parent = parent;
 800        last_in_target = find_last_in_target(sb, target);
 801        if (last_in_target < 0)
 802                return 1; /* nothing remains for this target */
 803
 804        fill_origin_blob(&sb->revs->diffopt, parent, &file_p);
 805        fill_origin_blob(&sb->revs->diffopt, target, &file_o);
 806        num_get_patch++;
 807
 808        diff_hunks(&file_p, &file_o, 0, blame_chunk_cb, &d);
 809        /* The rest (i.e. anything after tlno) are the same as the parent */
 810        blame_chunk(sb, d.tlno, d.plno, last_in_target, target, parent);
 811
 812        return 0;
 813}
 814
 815/*
 816 * The lines in blame_entry after splitting blames many times can become
 817 * very small and trivial, and at some point it becomes pointless to
 818 * blame the parents.  E.g. "\t\t}\n\t}\n\n" appears everywhere in any
 819 * ordinary C program, and it is not worth to say it was copied from
 820 * totally unrelated file in the parent.
 821 *
 822 * Compute how trivial the lines in the blame_entry are.
 823 */
 824static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
 825{
 826        unsigned score;
 827        const char *cp, *ep;
 828
 829        if (e->score)
 830                return e->score;
 831
 832        score = 1;
 833        cp = nth_line(sb, e->lno);
 834        ep = nth_line(sb, e->lno + e->num_lines);
 835        while (cp < ep) {
 836                unsigned ch = *((unsigned char *)cp);
 837                if (isalnum(ch))
 838                        score++;
 839                cp++;
 840        }
 841        e->score = score;
 842        return score;
 843}
 844
 845/*
 846 * best_so_far[] and this[] are both a split of an existing blame_entry
 847 * that passes blame to the parent.  Maintain best_so_far the best split
 848 * so far, by comparing this and best_so_far and copying this into
 849 * bst_so_far as needed.
 850 */
 851static void copy_split_if_better(struct scoreboard *sb,
 852                                 struct blame_entry *best_so_far,
 853                                 struct blame_entry *this)
 854{
 855        int i;
 856
 857        if (!this[1].suspect)
 858                return;
 859        if (best_so_far[1].suspect) {
 860                if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
 861                        return;
 862        }
 863
 864        for (i = 0; i < 3; i++)
 865                origin_incref(this[i].suspect);
 866        decref_split(best_so_far);
 867        memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
 868}
 869
 870/*
 871 * We are looking at a part of the final image represented by
 872 * ent (tlno and same are offset by ent->s_lno).
 873 * tlno is where we are looking at in the final image.
 874 * up to (but not including) same match preimage.
 875 * plno is where we are looking at in the preimage.
 876 *
 877 * <-------------- final image ---------------------->
 878 *       <------ent------>
 879 *         ^tlno ^same
 880 *    <---------preimage----->
 881 *         ^plno
 882 *
 883 * All line numbers are 0-based.
 884 */
 885static void handle_split(struct scoreboard *sb,
 886                         struct blame_entry *ent,
 887                         int tlno, int plno, int same,
 888                         struct origin *parent,
 889                         struct blame_entry *split)
 890{
 891        if (ent->num_lines <= tlno)
 892                return;
 893        if (tlno < same) {
 894                struct blame_entry this[3];
 895                tlno += ent->s_lno;
 896                same += ent->s_lno;
 897                split_overlap(this, ent, tlno, plno, same, parent);
 898                copy_split_if_better(sb, split, this);
 899                decref_split(this);
 900        }
 901}
 902
 903struct handle_split_cb_data {
 904        struct scoreboard *sb;
 905        struct blame_entry *ent;
 906        struct origin *parent;
 907        struct blame_entry *split;
 908        long plno;
 909        long tlno;
 910};
 911
 912static int handle_split_cb(long start_a, long count_a,
 913                           long start_b, long count_b, void *data)
 914{
 915        struct handle_split_cb_data *d = data;
 916        handle_split(d->sb, d->ent, d->tlno, d->plno, start_b, d->parent,
 917                     d->split);
 918        d->plno = start_a + count_a;
 919        d->tlno = start_b + count_b;
 920        return 0;
 921}
 922
 923/*
 924 * Find the lines from parent that are the same as ent so that
 925 * we can pass blames to it.  file_p has the blob contents for
 926 * the parent.
 927 */
 928static void find_copy_in_blob(struct scoreboard *sb,
 929                              struct blame_entry *ent,
 930                              struct origin *parent,
 931                              struct blame_entry *split,
 932                              mmfile_t *file_p)
 933{
 934        const char *cp;
 935        int cnt;
 936        mmfile_t file_o;
 937        struct handle_split_cb_data d;
 938
 939        memset(&d, 0, sizeof(d));
 940        d.sb = sb; d.ent = ent; d.parent = parent; d.split = split;
 941        /*
 942         * Prepare mmfile that contains only the lines in ent.
 943         */
 944        cp = nth_line(sb, ent->lno);
 945        file_o.ptr = (char *) cp;
 946        cnt = ent->num_lines;
 947
 948        while (cnt && cp < sb->final_buf + sb->final_buf_size) {
 949                if (*cp++ == '\n')
 950                        cnt--;
 951        }
 952        file_o.size = cp - file_o.ptr;
 953
 954        /*
 955         * file_o is a part of final image we are annotating.
 956         * file_p partially may match that image.
 957         */
 958        memset(split, 0, sizeof(struct blame_entry [3]));
 959        diff_hunks(file_p, &file_o, 1, handle_split_cb, &d);
 960        /* remainder, if any, all match the preimage */
 961        handle_split(sb, ent, d.tlno, d.plno, ent->num_lines, parent, split);
 962}
 963
 964/*
 965 * See if lines currently target is suspected for can be attributed to
 966 * parent.
 967 */
 968static int find_move_in_parent(struct scoreboard *sb,
 969                               struct origin *target,
 970                               struct origin *parent)
 971{
 972        int last_in_target, made_progress;
 973        struct blame_entry *e, split[3];
 974        mmfile_t file_p;
 975
 976        last_in_target = find_last_in_target(sb, target);
 977        if (last_in_target < 0)
 978                return 1; /* nothing remains for this target */
 979
 980        fill_origin_blob(&sb->revs->diffopt, parent, &file_p);
 981        if (!file_p.ptr)
 982                return 0;
 983
 984        made_progress = 1;
 985        while (made_progress) {
 986                made_progress = 0;
 987                for (e = sb->ent; e; e = e->next) {
 988                        if (e->guilty || !same_suspect(e->suspect, target) ||
 989                            ent_score(sb, e) < blame_move_score)
 990                                continue;
 991                        find_copy_in_blob(sb, e, parent, split, &file_p);
 992                        if (split[1].suspect &&
 993                            blame_move_score < ent_score(sb, &split[1])) {
 994                                split_blame(sb, split, e);
 995                                made_progress = 1;
 996                        }
 997                        decref_split(split);
 998                }
 999        }
1000        return 0;
1001}
1002
1003struct blame_list {
1004        struct blame_entry *ent;
1005        struct blame_entry split[3];
1006};
1007
1008/*
1009 * Count the number of entries the target is suspected for,
1010 * and prepare a list of entry and the best split.
1011 */
1012static struct blame_list *setup_blame_list(struct scoreboard *sb,
1013                                           struct origin *target,
1014                                           int min_score,
1015                                           int *num_ents_p)
1016{
1017        struct blame_entry *e;
1018        int num_ents, i;
1019        struct blame_list *blame_list = NULL;
1020
1021        for (e = sb->ent, num_ents = 0; e; e = e->next)
1022                if (!e->scanned && !e->guilty &&
1023                    same_suspect(e->suspect, target) &&
1024                    min_score < ent_score(sb, e))
1025                        num_ents++;
1026        if (num_ents) {
1027                blame_list = xcalloc(num_ents, sizeof(struct blame_list));
1028                for (e = sb->ent, i = 0; e; e = e->next)
1029                        if (!e->scanned && !e->guilty &&
1030                            same_suspect(e->suspect, target) &&
1031                            min_score < ent_score(sb, e))
1032                                blame_list[i++].ent = e;
1033        }
1034        *num_ents_p = num_ents;
1035        return blame_list;
1036}
1037
1038/*
1039 * Reset the scanned status on all entries.
1040 */
1041static void reset_scanned_flag(struct scoreboard *sb)
1042{
1043        struct blame_entry *e;
1044        for (e = sb->ent; e; e = e->next)
1045                e->scanned = 0;
1046}
1047
1048/*
1049 * For lines target is suspected for, see if we can find code movement
1050 * across file boundary from the parent commit.  porigin is the path
1051 * in the parent we already tried.
1052 */
1053static int find_copy_in_parent(struct scoreboard *sb,
1054                               struct origin *target,
1055                               struct commit *parent,
1056                               struct origin *porigin,
1057                               int opt)
1058{
1059        struct diff_options diff_opts;
1060        const char *paths[1];
1061        int i, j;
1062        int retval;
1063        struct blame_list *blame_list;
1064        int num_ents;
1065
1066        blame_list = setup_blame_list(sb, target, blame_copy_score, &num_ents);
1067        if (!blame_list)
1068                return 1; /* nothing remains for this target */
1069
1070        diff_setup(&diff_opts);
1071        DIFF_OPT_SET(&diff_opts, RECURSIVE);
1072        diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
1073
1074        paths[0] = NULL;
1075        diff_tree_setup_paths(paths, &diff_opts);
1076        diff_setup_done(&diff_opts);
1077
1078        /* Try "find copies harder" on new path if requested;
1079         * we do not want to use diffcore_rename() actually to
1080         * match things up; find_copies_harder is set only to
1081         * force diff_tree_sha1() to feed all filepairs to diff_queue,
1082         * and this code needs to be after diff_setup_done(), which
1083         * usually makes find-copies-harder imply copy detection.
1084         */
1085        if ((opt & PICKAXE_BLAME_COPY_HARDEST)
1086            || ((opt & PICKAXE_BLAME_COPY_HARDER)
1087                && (!porigin || strcmp(target->path, porigin->path))))
1088                DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
1089
1090        if (is_null_sha1(target->commit->object.sha1))
1091                do_diff_cache(parent->tree->object.sha1, &diff_opts);
1092        else
1093                diff_tree_sha1(parent->tree->object.sha1,
1094                               target->commit->tree->object.sha1,
1095                               "", &diff_opts);
1096
1097        if (!DIFF_OPT_TST(&diff_opts, FIND_COPIES_HARDER))
1098                diffcore_std(&diff_opts);
1099
1100        retval = 0;
1101        while (1) {
1102                int made_progress = 0;
1103
1104                for (i = 0; i < diff_queued_diff.nr; i++) {
1105                        struct diff_filepair *p = diff_queued_diff.queue[i];
1106                        struct origin *norigin;
1107                        mmfile_t file_p;
1108                        struct blame_entry this[3];
1109
1110                        if (!DIFF_FILE_VALID(p->one))
1111                                continue; /* does not exist in parent */
1112                        if (S_ISGITLINK(p->one->mode))
1113                                continue; /* ignore git links */
1114                        if (porigin && !strcmp(p->one->path, porigin->path))
1115                                /* find_move already dealt with this path */
1116                                continue;
1117
1118                        norigin = get_origin(sb, parent, p->one->path);
1119                        hashcpy(norigin->blob_sha1, p->one->sha1);
1120                        norigin->mode = p->one->mode;
1121                        fill_origin_blob(&sb->revs->diffopt, norigin, &file_p);
1122                        if (!file_p.ptr)
1123                                continue;
1124
1125                        for (j = 0; j < num_ents; j++) {
1126                                find_copy_in_blob(sb, blame_list[j].ent,
1127                                                  norigin, this, &file_p);
1128                                copy_split_if_better(sb, blame_list[j].split,
1129                                                     this);
1130                                decref_split(this);
1131                        }
1132                        origin_decref(norigin);
1133                }
1134
1135                for (j = 0; j < num_ents; j++) {
1136                        struct blame_entry *split = blame_list[j].split;
1137                        if (split[1].suspect &&
1138                            blame_copy_score < ent_score(sb, &split[1])) {
1139                                split_blame(sb, split, blame_list[j].ent);
1140                                made_progress = 1;
1141                        }
1142                        else
1143                                blame_list[j].ent->scanned = 1;
1144                        decref_split(split);
1145                }
1146                free(blame_list);
1147
1148                if (!made_progress)
1149                        break;
1150                blame_list = setup_blame_list(sb, target, blame_copy_score, &num_ents);
1151                if (!blame_list) {
1152                        retval = 1;
1153                        break;
1154                }
1155        }
1156        reset_scanned_flag(sb);
1157        diff_flush(&diff_opts);
1158        diff_tree_release_paths(&diff_opts);
1159        return retval;
1160}
1161
1162/*
1163 * The blobs of origin and porigin exactly match, so everything
1164 * origin is suspected for can be blamed on the parent.
1165 */
1166static void pass_whole_blame(struct scoreboard *sb,
1167                             struct origin *origin, struct origin *porigin)
1168{
1169        struct blame_entry *e;
1170
1171        if (!porigin->file.ptr && origin->file.ptr) {
1172                /* Steal its file */
1173                porigin->file = origin->file;
1174                origin->file.ptr = NULL;
1175        }
1176        for (e = sb->ent; e; e = e->next) {
1177                if (!same_suspect(e->suspect, origin))
1178                        continue;
1179                origin_incref(porigin);
1180                origin_decref(e->suspect);
1181                e->suspect = porigin;
1182        }
1183}
1184
1185/*
1186 * We pass blame from the current commit to its parents.  We keep saying
1187 * "parent" (and "porigin"), but what we mean is to find scapegoat to
1188 * exonerate ourselves.
1189 */
1190static struct commit_list *first_scapegoat(struct rev_info *revs, struct commit *commit)
1191{
1192        if (!reverse)
1193                return commit->parents;
1194        return lookup_decoration(&revs->children, &commit->object);
1195}
1196
1197static int num_scapegoats(struct rev_info *revs, struct commit *commit)
1198{
1199        int cnt;
1200        struct commit_list *l = first_scapegoat(revs, commit);
1201        for (cnt = 0; l; l = l->next)
1202                cnt++;
1203        return cnt;
1204}
1205
1206#define MAXSG 16
1207
1208static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
1209{
1210        struct rev_info *revs = sb->revs;
1211        int i, pass, num_sg;
1212        struct commit *commit = origin->commit;
1213        struct commit_list *sg;
1214        struct origin *sg_buf[MAXSG];
1215        struct origin *porigin, **sg_origin = sg_buf;
1216
1217        num_sg = num_scapegoats(revs, commit);
1218        if (!num_sg)
1219                goto finish;
1220        else if (num_sg < ARRAY_SIZE(sg_buf))
1221                memset(sg_buf, 0, sizeof(sg_buf));
1222        else
1223                sg_origin = xcalloc(num_sg, sizeof(*sg_origin));
1224
1225        /*
1226         * The first pass looks for unrenamed path to optimize for
1227         * common cases, then we look for renames in the second pass.
1228         */
1229        for (pass = 0; pass < 2; pass++) {
1230                struct origin *(*find)(struct scoreboard *,
1231                                       struct commit *, struct origin *);
1232                find = pass ? find_rename : find_origin;
1233
1234                for (i = 0, sg = first_scapegoat(revs, commit);
1235                     i < num_sg && sg;
1236                     sg = sg->next, i++) {
1237                        struct commit *p = sg->item;
1238                        int j, same;
1239
1240                        if (sg_origin[i])
1241                                continue;
1242                        if (parse_commit(p))
1243                                continue;
1244                        porigin = find(sb, p, origin);
1245                        if (!porigin)
1246                                continue;
1247                        if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) {
1248                                pass_whole_blame(sb, origin, porigin);
1249                                origin_decref(porigin);
1250                                goto finish;
1251                        }
1252                        for (j = same = 0; j < i; j++)
1253                                if (sg_origin[j] &&
1254                                    !hashcmp(sg_origin[j]->blob_sha1,
1255                                             porigin->blob_sha1)) {
1256                                        same = 1;
1257                                        break;
1258                                }
1259                        if (!same)
1260                                sg_origin[i] = porigin;
1261                        else
1262                                origin_decref(porigin);
1263                }
1264        }
1265
1266        num_commits++;
1267        for (i = 0, sg = first_scapegoat(revs, commit);
1268             i < num_sg && sg;
1269             sg = sg->next, i++) {
1270                struct origin *porigin = sg_origin[i];
1271                if (!porigin)
1272                        continue;
1273                if (!origin->previous) {
1274                        origin_incref(porigin);
1275                        origin->previous = porigin;
1276                }
1277                if (pass_blame_to_parent(sb, origin, porigin))
1278                        goto finish;
1279        }
1280
1281        /*
1282         * Optionally find moves in parents' files.
1283         */
1284        if (opt & PICKAXE_BLAME_MOVE)
1285                for (i = 0, sg = first_scapegoat(revs, commit);
1286                     i < num_sg && sg;
1287                     sg = sg->next, i++) {
1288                        struct origin *porigin = sg_origin[i];
1289                        if (!porigin)
1290                                continue;
1291                        if (find_move_in_parent(sb, origin, porigin))
1292                                goto finish;
1293                }
1294
1295        /*
1296         * Optionally find copies from parents' files.
1297         */
1298        if (opt & PICKAXE_BLAME_COPY)
1299                for (i = 0, sg = first_scapegoat(revs, commit);
1300                     i < num_sg && sg;
1301                     sg = sg->next, i++) {
1302                        struct origin *porigin = sg_origin[i];
1303                        if (find_copy_in_parent(sb, origin, sg->item,
1304                                                porigin, opt))
1305                                goto finish;
1306                }
1307
1308 finish:
1309        for (i = 0; i < num_sg; i++) {
1310                if (sg_origin[i]) {
1311                        drop_origin_blob(sg_origin[i]);
1312                        origin_decref(sg_origin[i]);
1313                }
1314        }
1315        drop_origin_blob(origin);
1316        if (sg_buf != sg_origin)
1317                free(sg_origin);
1318}
1319
1320/*
1321 * Information on commits, used for output.
1322 */
1323struct commit_info {
1324        const char *author;
1325        const char *author_mail;
1326        unsigned long author_time;
1327        const char *author_tz;
1328
1329        /* filled only when asked for details */
1330        const char *committer;
1331        const char *committer_mail;
1332        unsigned long committer_time;
1333        const char *committer_tz;
1334
1335        const char *summary;
1336};
1337
1338/*
1339 * Parse author/committer line in the commit object buffer
1340 */
1341static void get_ac_line(const char *inbuf, const char *what,
1342                        int person_len, char *person,
1343                        int mail_len, char *mail,
1344                        unsigned long *time, const char **tz)
1345{
1346        int len, tzlen, maillen;
1347        char *tmp, *endp, *timepos, *mailpos;
1348
1349        tmp = strstr(inbuf, what);
1350        if (!tmp)
1351                goto error_out;
1352        tmp += strlen(what);
1353        endp = strchr(tmp, '\n');
1354        if (!endp)
1355                len = strlen(tmp);
1356        else
1357                len = endp - tmp;
1358        if (person_len <= len) {
1359        error_out:
1360                /* Ugh */
1361                *tz = "(unknown)";
1362                strcpy(person, *tz);
1363                strcpy(mail, *tz);
1364                *time = 0;
1365                return;
1366        }
1367        memcpy(person, tmp, len);
1368
1369        tmp = person;
1370        tmp += len;
1371        *tmp = 0;
1372        while (person < tmp && *tmp != ' ')
1373                tmp--;
1374        if (tmp <= person)
1375                goto error_out;
1376        *tz = tmp+1;
1377        tzlen = (person+len)-(tmp+1);
1378
1379        *tmp = 0;
1380        while (person < tmp && *tmp != ' ')
1381                tmp--;
1382        if (tmp <= person)
1383                goto error_out;
1384        *time = strtoul(tmp, NULL, 10);
1385        timepos = tmp;
1386
1387        *tmp = 0;
1388        while (person < tmp && !(*tmp == ' ' && tmp[1] == '<'))
1389                tmp--;
1390        if (tmp <= person)
1391                return;
1392        mailpos = tmp + 1;
1393        *tmp = 0;
1394        maillen = timepos - tmp;
1395        memcpy(mail, mailpos, maillen);
1396
1397        if (!mailmap.nr)
1398                return;
1399
1400        /*
1401         * mailmap expansion may make the name longer.
1402         * make room by pushing stuff down.
1403         */
1404        tmp = person + person_len - (tzlen + 1);
1405        memmove(tmp, *tz, tzlen);
1406        tmp[tzlen] = 0;
1407        *tz = tmp;
1408
1409        /*
1410         * Now, convert both name and e-mail using mailmap
1411         */
1412        if (map_user(&mailmap, mail+1, mail_len-1, person, tmp-person-1)) {
1413                /* Add a trailing '>' to email, since map_user returns plain emails
1414                   Note: It already has '<', since we replace from mail+1 */
1415                mailpos = memchr(mail, '\0', mail_len);
1416                if (mailpos && mailpos-mail < mail_len - 1) {
1417                        *mailpos = '>';
1418                        *(mailpos+1) = '\0';
1419                }
1420        }
1421}
1422
1423static void get_commit_info(struct commit *commit,
1424                            struct commit_info *ret,
1425                            int detailed)
1426{
1427        int len;
1428        const char *subject, *encoding;
1429        char *reencoded, *message;
1430        static char author_name[1024];
1431        static char author_mail[1024];
1432        static char committer_name[1024];
1433        static char committer_mail[1024];
1434        static char summary_buf[1024];
1435
1436        /*
1437         * We've operated without save_commit_buffer, so
1438         * we now need to populate them for output.
1439         */
1440        if (!commit->buffer) {
1441                enum object_type type;
1442                unsigned long size;
1443                commit->buffer =
1444                        read_sha1_file(commit->object.sha1, &type, &size);
1445                if (!commit->buffer)
1446                        die("Cannot read commit %s",
1447                            sha1_to_hex(commit->object.sha1));
1448        }
1449        encoding = get_log_output_encoding();
1450        reencoded = logmsg_reencode(commit, encoding);
1451        message   = reencoded ? reencoded : commit->buffer;
1452        ret->author = author_name;
1453        ret->author_mail = author_mail;
1454        get_ac_line(message, "\nauthor ",
1455                    sizeof(author_name), author_name,
1456                    sizeof(author_mail), author_mail,
1457                    &ret->author_time, &ret->author_tz);
1458
1459        if (!detailed) {
1460                free(reencoded);
1461                return;
1462        }
1463
1464        ret->committer = committer_name;
1465        ret->committer_mail = committer_mail;
1466        get_ac_line(message, "\ncommitter ",
1467                    sizeof(committer_name), committer_name,
1468                    sizeof(committer_mail), committer_mail,
1469                    &ret->committer_time, &ret->committer_tz);
1470
1471        ret->summary = summary_buf;
1472        len = find_commit_subject(message, &subject);
1473        if (len && len < sizeof(summary_buf)) {
1474                memcpy(summary_buf, subject, len);
1475                summary_buf[len] = 0;
1476        } else {
1477                sprintf(summary_buf, "(%s)", sha1_to_hex(commit->object.sha1));
1478        }
1479        free(reencoded);
1480}
1481
1482/*
1483 * To allow LF and other nonportable characters in pathnames,
1484 * they are c-style quoted as needed.
1485 */
1486static void write_filename_info(const char *path)
1487{
1488        printf("filename ");
1489        write_name_quoted(path, stdout, '\n');
1490}
1491
1492/*
1493 * Porcelain/Incremental format wants to show a lot of details per
1494 * commit.  Instead of repeating this every line, emit it only once,
1495 * the first time each commit appears in the output (unless the
1496 * user has specifically asked for us to repeat).
1497 */
1498static int emit_one_suspect_detail(struct origin *suspect, int repeat)
1499{
1500        struct commit_info ci;
1501
1502        if (!repeat && (suspect->commit->object.flags & METAINFO_SHOWN))
1503                return 0;
1504
1505        suspect->commit->object.flags |= METAINFO_SHOWN;
1506        get_commit_info(suspect->commit, &ci, 1);
1507        printf("author %s\n", ci.author);
1508        printf("author-mail %s\n", ci.author_mail);
1509        printf("author-time %lu\n", ci.author_time);
1510        printf("author-tz %s\n", ci.author_tz);
1511        printf("committer %s\n", ci.committer);
1512        printf("committer-mail %s\n", ci.committer_mail);
1513        printf("committer-time %lu\n", ci.committer_time);
1514        printf("committer-tz %s\n", ci.committer_tz);
1515        printf("summary %s\n", ci.summary);
1516        if (suspect->commit->object.flags & UNINTERESTING)
1517                printf("boundary\n");
1518        if (suspect->previous) {
1519                struct origin *prev = suspect->previous;
1520                printf("previous %s ", sha1_to_hex(prev->commit->object.sha1));
1521                write_name_quoted(prev->path, stdout, '\n');
1522        }
1523        return 1;
1524}
1525
1526/*
1527 * The blame_entry is found to be guilty for the range.  Mark it
1528 * as such, and show it in incremental output.
1529 */
1530static void found_guilty_entry(struct blame_entry *ent)
1531{
1532        if (ent->guilty)
1533                return;
1534        ent->guilty = 1;
1535        if (incremental) {
1536                struct origin *suspect = ent->suspect;
1537
1538                printf("%s %d %d %d\n",
1539                       sha1_to_hex(suspect->commit->object.sha1),
1540                       ent->s_lno + 1, ent->lno + 1, ent->num_lines);
1541                emit_one_suspect_detail(suspect, 0);
1542                write_filename_info(suspect->path);
1543                maybe_flush_or_die(stdout, "stdout");
1544        }
1545}
1546
1547/*
1548 * The main loop -- while the scoreboard has lines whose true origin
1549 * is still unknown, pick one blame_entry, and allow its current
1550 * suspect to pass blames to its parents.
1551 */
1552static void assign_blame(struct scoreboard *sb, int opt)
1553{
1554        struct rev_info *revs = sb->revs;
1555
1556        while (1) {
1557                struct blame_entry *ent;
1558                struct commit *commit;
1559                struct origin *suspect = NULL;
1560
1561                /* find one suspect to break down */
1562                for (ent = sb->ent; !suspect && ent; ent = ent->next)
1563                        if (!ent->guilty)
1564                                suspect = ent->suspect;
1565                if (!suspect)
1566                        return; /* all done */
1567
1568                /*
1569                 * We will use this suspect later in the loop,
1570                 * so hold onto it in the meantime.
1571                 */
1572                origin_incref(suspect);
1573                commit = suspect->commit;
1574                if (!commit->object.parsed)
1575                        parse_commit(commit);
1576                if (reverse ||
1577                    (!(commit->object.flags & UNINTERESTING) &&
1578                     !(revs->max_age != -1 && commit->date < revs->max_age)))
1579                        pass_blame(sb, suspect, opt);
1580                else {
1581                        commit->object.flags |= UNINTERESTING;
1582                        if (commit->object.parsed)
1583                                mark_parents_uninteresting(commit);
1584                }
1585                /* treat root commit as boundary */
1586                if (!commit->parents && !show_root)
1587                        commit->object.flags |= UNINTERESTING;
1588
1589                /* Take responsibility for the remaining entries */
1590                for (ent = sb->ent; ent; ent = ent->next)
1591                        if (same_suspect(ent->suspect, suspect))
1592                                found_guilty_entry(ent);
1593                origin_decref(suspect);
1594
1595                if (DEBUG) /* sanity */
1596                        sanity_check_refcnt(sb);
1597        }
1598}
1599
1600static const char *format_time(unsigned long time, const char *tz_str,
1601                               int show_raw_time)
1602{
1603        static char time_buf[128];
1604        const char *time_str;
1605        int time_len;
1606        int tz;
1607
1608        if (show_raw_time) {
1609                snprintf(time_buf, sizeof(time_buf), "%lu %s", time, tz_str);
1610        }
1611        else {
1612                tz = atoi(tz_str);
1613                time_str = show_date(time, tz, blame_date_mode);
1614                time_len = strlen(time_str);
1615                memcpy(time_buf, time_str, time_len);
1616                memset(time_buf + time_len, ' ', blame_date_width - time_len);
1617        }
1618        return time_buf;
1619}
1620
1621#define OUTPUT_ANNOTATE_COMPAT  001
1622#define OUTPUT_LONG_OBJECT_NAME 002
1623#define OUTPUT_RAW_TIMESTAMP    004
1624#define OUTPUT_PORCELAIN        010
1625#define OUTPUT_SHOW_NAME        020
1626#define OUTPUT_SHOW_NUMBER      040
1627#define OUTPUT_SHOW_SCORE      0100
1628#define OUTPUT_NO_AUTHOR       0200
1629#define OUTPUT_SHOW_EMAIL       0400
1630#define OUTPUT_LINE_PORCELAIN 01000
1631
1632static void emit_porcelain_details(struct origin *suspect, int repeat)
1633{
1634        if (emit_one_suspect_detail(suspect, repeat) ||
1635            (suspect->commit->object.flags & MORE_THAN_ONE_PATH))
1636                write_filename_info(suspect->path);
1637}
1638
1639static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent,
1640                           int opt)
1641{
1642        int repeat = opt & OUTPUT_LINE_PORCELAIN;
1643        int cnt;
1644        const char *cp;
1645        struct origin *suspect = ent->suspect;
1646        char hex[41];
1647
1648        strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1649        printf("%s%c%d %d %d\n",
1650               hex,
1651               ent->guilty ? ' ' : '*', /* purely for debugging */
1652               ent->s_lno + 1,
1653               ent->lno + 1,
1654               ent->num_lines);
1655        emit_porcelain_details(suspect, repeat);
1656
1657        cp = nth_line(sb, ent->lno);
1658        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1659                char ch;
1660                if (cnt) {
1661                        printf("%s %d %d\n", hex,
1662                               ent->s_lno + 1 + cnt,
1663                               ent->lno + 1 + cnt);
1664                        if (repeat)
1665                                emit_porcelain_details(suspect, 1);
1666                }
1667                putchar('\t');
1668                do {
1669                        ch = *cp++;
1670                        putchar(ch);
1671                } while (ch != '\n' &&
1672                         cp < sb->final_buf + sb->final_buf_size);
1673        }
1674
1675        if (sb->final_buf_size && cp[-1] != '\n')
1676                putchar('\n');
1677}
1678
1679static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
1680{
1681        int cnt;
1682        const char *cp;
1683        struct origin *suspect = ent->suspect;
1684        struct commit_info ci;
1685        char hex[41];
1686        int show_raw_time = !!(opt & OUTPUT_RAW_TIMESTAMP);
1687
1688        get_commit_info(suspect->commit, &ci, 1);
1689        strcpy(hex, sha1_to_hex(suspect->commit->object.sha1));
1690
1691        cp = nth_line(sb, ent->lno);
1692        for (cnt = 0; cnt < ent->num_lines; cnt++) {
1693                char ch;
1694                int length = (opt & OUTPUT_LONG_OBJECT_NAME) ? 40 : abbrev;
1695
1696                if (suspect->commit->object.flags & UNINTERESTING) {
1697                        if (blank_boundary)
1698                                memset(hex, ' ', length);
1699                        else if (!(opt & OUTPUT_ANNOTATE_COMPAT)) {
1700                                length--;
1701                                putchar('^');
1702                        }
1703                }
1704
1705                printf("%.*s", length, hex);
1706                if (opt & OUTPUT_ANNOTATE_COMPAT) {
1707                        const char *name;
1708                        if (opt & OUTPUT_SHOW_EMAIL)
1709                                name = ci.author_mail;
1710                        else
1711                                name = ci.author;
1712                        printf("\t(%10s\t%10s\t%d)", name,
1713                               format_time(ci.author_time, ci.author_tz,
1714                                           show_raw_time),
1715                               ent->lno + 1 + cnt);
1716                } else {
1717                        if (opt & OUTPUT_SHOW_SCORE)
1718                                printf(" %*d %02d",
1719                                       max_score_digits, ent->score,
1720                                       ent->suspect->refcnt);
1721                        if (opt & OUTPUT_SHOW_NAME)
1722                                printf(" %-*.*s", longest_file, longest_file,
1723                                       suspect->path);
1724                        if (opt & OUTPUT_SHOW_NUMBER)
1725                                printf(" %*d", max_orig_digits,
1726                                       ent->s_lno + 1 + cnt);
1727
1728                        if (!(opt & OUTPUT_NO_AUTHOR)) {
1729                                const char *name;
1730                                int pad;
1731                                if (opt & OUTPUT_SHOW_EMAIL)
1732                                        name = ci.author_mail;
1733                                else
1734                                        name = ci.author;
1735                                pad = longest_author - utf8_strwidth(name);
1736                                printf(" (%s%*s %10s",
1737                                       name, pad, "",
1738                                       format_time(ci.author_time,
1739                                                   ci.author_tz,
1740                                                   show_raw_time));
1741                        }
1742                        printf(" %*d) ",
1743                               max_digits, ent->lno + 1 + cnt);
1744                }
1745                do {
1746                        ch = *cp++;
1747                        putchar(ch);
1748                } while (ch != '\n' &&
1749                         cp < sb->final_buf + sb->final_buf_size);
1750        }
1751
1752        if (sb->final_buf_size && cp[-1] != '\n')
1753                putchar('\n');
1754}
1755
1756static void output(struct scoreboard *sb, int option)
1757{
1758        struct blame_entry *ent;
1759
1760        if (option & OUTPUT_PORCELAIN) {
1761                for (ent = sb->ent; ent; ent = ent->next) {
1762                        struct blame_entry *oth;
1763                        struct origin *suspect = ent->suspect;
1764                        struct commit *commit = suspect->commit;
1765                        if (commit->object.flags & MORE_THAN_ONE_PATH)
1766                                continue;
1767                        for (oth = ent->next; oth; oth = oth->next) {
1768                                if ((oth->suspect->commit != commit) ||
1769                                    !strcmp(oth->suspect->path, suspect->path))
1770                                        continue;
1771                                commit->object.flags |= MORE_THAN_ONE_PATH;
1772                                break;
1773                        }
1774                }
1775        }
1776
1777        for (ent = sb->ent; ent; ent = ent->next) {
1778                if (option & OUTPUT_PORCELAIN)
1779                        emit_porcelain(sb, ent, option);
1780                else {
1781                        emit_other(sb, ent, option);
1782                }
1783        }
1784}
1785
1786/*
1787 * To allow quick access to the contents of nth line in the
1788 * final image, prepare an index in the scoreboard.
1789 */
1790static int prepare_lines(struct scoreboard *sb)
1791{
1792        const char *buf = sb->final_buf;
1793        unsigned long len = sb->final_buf_size;
1794        int num = 0, incomplete = 0, bol = 1;
1795
1796        if (len && buf[len-1] != '\n')
1797                incomplete++; /* incomplete line at the end */
1798        while (len--) {
1799                if (bol) {
1800                        sb->lineno = xrealloc(sb->lineno,
1801                                              sizeof(int *) * (num + 1));
1802                        sb->lineno[num] = buf - sb->final_buf;
1803                        bol = 0;
1804                }
1805                if (*buf++ == '\n') {
1806                        num++;
1807                        bol = 1;
1808                }
1809        }
1810        sb->lineno = xrealloc(sb->lineno,
1811                              sizeof(int *) * (num + incomplete + 1));
1812        sb->lineno[num + incomplete] = buf - sb->final_buf;
1813        sb->num_lines = num + incomplete;
1814        return sb->num_lines;
1815}
1816
1817/*
1818 * Add phony grafts for use with -S; this is primarily to
1819 * support git's cvsserver that wants to give a linear history
1820 * to its clients.
1821 */
1822static int read_ancestry(const char *graft_file)
1823{
1824        FILE *fp = fopen(graft_file, "r");
1825        char buf[1024];
1826        if (!fp)
1827                return -1;
1828        while (fgets(buf, sizeof(buf), fp)) {
1829                /* The format is just "Commit Parent1 Parent2 ...\n" */
1830                int len = strlen(buf);
1831                struct commit_graft *graft = read_graft_line(buf, len);
1832                if (graft)
1833                        register_commit_graft(graft, 0);
1834        }
1835        fclose(fp);
1836        return 0;
1837}
1838
1839static int update_auto_abbrev(int auto_abbrev, struct origin *suspect)
1840{
1841        const char *uniq = find_unique_abbrev(suspect->commit->object.sha1,
1842                                              auto_abbrev);
1843        int len = strlen(uniq);
1844        if (auto_abbrev < len)
1845                return len;
1846        return auto_abbrev;
1847}
1848
1849/*
1850 * How many columns do we need to show line numbers, authors,
1851 * and filenames?
1852 */
1853static void find_alignment(struct scoreboard *sb, int *option)
1854{
1855        int longest_src_lines = 0;
1856        int longest_dst_lines = 0;
1857        unsigned largest_score = 0;
1858        struct blame_entry *e;
1859        int compute_auto_abbrev = (abbrev < 0);
1860        int auto_abbrev = default_abbrev;
1861
1862        for (e = sb->ent; e; e = e->next) {
1863                struct origin *suspect = e->suspect;
1864                struct commit_info ci;
1865                int num;
1866
1867                if (compute_auto_abbrev)
1868                        auto_abbrev = update_auto_abbrev(auto_abbrev, suspect);
1869                if (strcmp(suspect->path, sb->path))
1870                        *option |= OUTPUT_SHOW_NAME;
1871                num = strlen(suspect->path);
1872                if (longest_file < num)
1873                        longest_file = num;
1874                if (!(suspect->commit->object.flags & METAINFO_SHOWN)) {
1875                        suspect->commit->object.flags |= METAINFO_SHOWN;
1876                        get_commit_info(suspect->commit, &ci, 1);
1877                        if (*option & OUTPUT_SHOW_EMAIL)
1878                                num = utf8_strwidth(ci.author_mail);
1879                        else
1880                                num = utf8_strwidth(ci.author);
1881                        if (longest_author < num)
1882                                longest_author = num;
1883                }
1884                num = e->s_lno + e->num_lines;
1885                if (longest_src_lines < num)
1886                        longest_src_lines = num;
1887                num = e->lno + e->num_lines;
1888                if (longest_dst_lines < num)
1889                        longest_dst_lines = num;
1890                if (largest_score < ent_score(sb, e))
1891                        largest_score = ent_score(sb, e);
1892        }
1893        max_orig_digits = decimal_width(longest_src_lines);
1894        max_digits = decimal_width(longest_dst_lines);
1895        max_score_digits = decimal_width(largest_score);
1896
1897        if (compute_auto_abbrev)
1898                /* one more abbrev length is needed for the boundary commit */
1899                abbrev = auto_abbrev + 1;
1900}
1901
1902/*
1903 * For debugging -- origin is refcounted, and this asserts that
1904 * we do not underflow.
1905 */
1906static void sanity_check_refcnt(struct scoreboard *sb)
1907{
1908        int baa = 0;
1909        struct blame_entry *ent;
1910
1911        for (ent = sb->ent; ent; ent = ent->next) {
1912                /* Nobody should have zero or negative refcnt */
1913                if (ent->suspect->refcnt <= 0) {
1914                        fprintf(stderr, "%s in %s has negative refcnt %d\n",
1915                                ent->suspect->path,
1916                                sha1_to_hex(ent->suspect->commit->object.sha1),
1917                                ent->suspect->refcnt);
1918                        baa = 1;
1919                }
1920        }
1921        if (baa) {
1922                int opt = 0160;
1923                find_alignment(sb, &opt);
1924                output(sb, opt);
1925                die("Baa %d!", baa);
1926        }
1927}
1928
1929/*
1930 * Used for the command line parsing; check if the path exists
1931 * in the working tree.
1932 */
1933static int has_string_in_work_tree(const char *path)
1934{
1935        struct stat st;
1936        return !lstat(path, &st);
1937}
1938
1939static unsigned parse_score(const char *arg)
1940{
1941        char *end;
1942        unsigned long score = strtoul(arg, &end, 10);
1943        if (*end)
1944                return 0;
1945        return score;
1946}
1947
1948static const char *add_prefix(const char *prefix, const char *path)
1949{
1950        return prefix_path(prefix, prefix ? strlen(prefix) : 0, path);
1951}
1952
1953/*
1954 * Parsing of (comma separated) one item in the -L option
1955 */
1956static const char *parse_loc(const char *spec,
1957                             struct scoreboard *sb, long lno,
1958                             long begin, long *ret)
1959{
1960        char *term;
1961        const char *line;
1962        long num;
1963        int reg_error;
1964        regex_t regexp;
1965        regmatch_t match[1];
1966
1967        /* Allow "-L <something>,+20" to mean starting at <something>
1968         * for 20 lines, or "-L <something>,-5" for 5 lines ending at
1969         * <something>.
1970         */
1971        if (1 < begin && (spec[0] == '+' || spec[0] == '-')) {
1972                num = strtol(spec + 1, &term, 10);
1973                if (term != spec + 1) {
1974                        if (spec[0] == '-')
1975                                num = 0 - num;
1976                        if (0 < num)
1977                                *ret = begin + num - 2;
1978                        else if (!num)
1979                                *ret = begin;
1980                        else
1981                                *ret = begin + num;
1982                        return term;
1983                }
1984                return spec;
1985        }
1986        num = strtol(spec, &term, 10);
1987        if (term != spec) {
1988                *ret = num;
1989                return term;
1990        }
1991        if (spec[0] != '/')
1992                return spec;
1993
1994        /* it could be a regexp of form /.../ */
1995        for (term = (char *) spec + 1; *term && *term != '/'; term++) {
1996                if (*term == '\\')
1997                        term++;
1998        }
1999        if (*term != '/')
2000                return spec;
2001
2002        /* try [spec+1 .. term-1] as regexp */
2003        *term = 0;
2004        begin--; /* input is in human terms */
2005        line = nth_line(sb, begin);
2006
2007        if (!(reg_error = regcomp(&regexp, spec + 1, REG_NEWLINE)) &&
2008            !(reg_error = regexec(&regexp, line, 1, match, 0))) {
2009                const char *cp = line + match[0].rm_so;
2010                const char *nline;
2011
2012                while (begin++ < lno) {
2013                        nline = nth_line(sb, begin);
2014                        if (line <= cp && cp < nline)
2015                                break;
2016                        line = nline;
2017                }
2018                *ret = begin;
2019                regfree(&regexp);
2020                *term++ = '/';
2021                return term;
2022        }
2023        else {
2024                char errbuf[1024];
2025                regerror(reg_error, &regexp, errbuf, 1024);
2026                die("-L parameter '%s': %s", spec + 1, errbuf);
2027        }
2028}
2029
2030/*
2031 * Parsing of -L option
2032 */
2033static void prepare_blame_range(struct scoreboard *sb,
2034                                const char *bottomtop,
2035                                long lno,
2036                                long *bottom, long *top)
2037{
2038        const char *term;
2039
2040        term = parse_loc(bottomtop, sb, lno, 1, bottom);
2041        if (*term == ',') {
2042                term = parse_loc(term + 1, sb, lno, *bottom + 1, top);
2043                if (*term)
2044                        usage(blame_usage);
2045        }
2046        if (*term)
2047                usage(blame_usage);
2048}
2049
2050static int git_blame_config(const char *var, const char *value, void *cb)
2051{
2052        if (!strcmp(var, "blame.showroot")) {
2053                show_root = git_config_bool(var, value);
2054                return 0;
2055        }
2056        if (!strcmp(var, "blame.blankboundary")) {
2057                blank_boundary = git_config_bool(var, value);
2058                return 0;
2059        }
2060        if (!strcmp(var, "blame.date")) {
2061                if (!value)
2062                        return config_error_nonbool(var);
2063                blame_date_mode = parse_date_format(value);
2064                return 0;
2065        }
2066
2067        if (userdiff_config(var, value) < 0)
2068                return -1;
2069
2070        return git_default_config(var, value, cb);
2071}
2072
2073static void verify_working_tree_path(struct commit *work_tree, const char *path)
2074{
2075        struct commit_list *parents;
2076
2077        for (parents = work_tree->parents; parents; parents = parents->next) {
2078                const unsigned char *commit_sha1 = parents->item->object.sha1;
2079                unsigned char blob_sha1[20];
2080                unsigned mode;
2081
2082                if (!get_tree_entry(commit_sha1, path, blob_sha1, &mode) &&
2083                    sha1_object_info(blob_sha1, NULL) == OBJ_BLOB)
2084                        return;
2085        }
2086        die("no such path '%s' in HEAD", path);
2087}
2088
2089static struct commit_list **append_parent(struct commit_list **tail, const unsigned char *sha1)
2090{
2091        struct commit *parent;
2092
2093        parent = lookup_commit_reference(sha1);
2094        if (!parent)
2095                die("no such commit %s", sha1_to_hex(sha1));
2096        return &commit_list_insert(parent, tail)->next;
2097}
2098
2099static void append_merge_parents(struct commit_list **tail)
2100{
2101        int merge_head;
2102        const char *merge_head_file = git_path("MERGE_HEAD");
2103        struct strbuf line = STRBUF_INIT;
2104
2105        merge_head = open(merge_head_file, O_RDONLY);
2106        if (merge_head < 0) {
2107                if (errno == ENOENT)
2108                        return;
2109                die("cannot open '%s' for reading", merge_head_file);
2110        }
2111
2112        while (!strbuf_getwholeline_fd(&line, merge_head, '\n')) {
2113                unsigned char sha1[20];
2114                if (line.len < 40 || get_sha1_hex(line.buf, sha1))
2115                        die("unknown line in '%s': %s", merge_head_file, line.buf);
2116                tail = append_parent(tail, sha1);
2117        }
2118        close(merge_head);
2119        strbuf_release(&line);
2120}
2121
2122/*
2123 * Prepare a dummy commit that represents the work tree (or staged) item.
2124 * Note that annotating work tree item never works in the reverse.
2125 */
2126static struct commit *fake_working_tree_commit(struct diff_options *opt,
2127                                               const char *path,
2128                                               const char *contents_from)
2129{
2130        struct commit *commit;
2131        struct origin *origin;
2132        struct commit_list **parent_tail, *parent;
2133        unsigned char head_sha1[20];
2134        struct strbuf buf = STRBUF_INIT;
2135        const char *ident;
2136        time_t now;
2137        int size, len;
2138        struct cache_entry *ce;
2139        unsigned mode;
2140        struct strbuf msg = STRBUF_INIT;
2141
2142        time(&now);
2143        commit = xcalloc(1, sizeof(*commit));
2144        commit->object.parsed = 1;
2145        commit->date = now;
2146        commit->object.type = OBJ_COMMIT;
2147        parent_tail = &commit->parents;
2148
2149        if (!resolve_ref_unsafe("HEAD", head_sha1, 1, NULL))
2150                die("no such ref: HEAD");
2151
2152        parent_tail = append_parent(parent_tail, head_sha1);
2153        append_merge_parents(parent_tail);
2154        verify_working_tree_path(commit, path);
2155
2156        origin = make_origin(commit, path);
2157
2158        ident = fmt_ident("Not Committed Yet", "not.committed.yet", NULL, 0);
2159        strbuf_addstr(&msg, "tree 0000000000000000000000000000000000000000\n");
2160        for (parent = commit->parents; parent; parent = parent->next)
2161                strbuf_addf(&msg, "parent %s\n",
2162                            sha1_to_hex(parent->item->object.sha1));
2163        strbuf_addf(&msg,
2164                    "author %s\n"
2165                    "committer %s\n\n"
2166                    "Version of %s from %s\n",
2167                    ident, ident, path,
2168                    (!contents_from ? path :
2169                     (!strcmp(contents_from, "-") ? "standard input" : contents_from)));
2170        commit->buffer = strbuf_detach(&msg, NULL);
2171
2172        if (!contents_from || strcmp("-", contents_from)) {
2173                struct stat st;
2174                const char *read_from;
2175                char *buf_ptr;
2176                unsigned long buf_len;
2177
2178                if (contents_from) {
2179                        if (stat(contents_from, &st) < 0)
2180                                die_errno("Cannot stat '%s'", contents_from);
2181                        read_from = contents_from;
2182                }
2183                else {
2184                        if (lstat(path, &st) < 0)
2185                                die_errno("Cannot lstat '%s'", path);
2186                        read_from = path;
2187                }
2188                mode = canon_mode(st.st_mode);
2189
2190                switch (st.st_mode & S_IFMT) {
2191                case S_IFREG:
2192                        if (DIFF_OPT_TST(opt, ALLOW_TEXTCONV) &&
2193                            textconv_object(read_from, mode, null_sha1, 0, &buf_ptr, &buf_len))
2194                                strbuf_attach(&buf, buf_ptr, buf_len, buf_len + 1);
2195                        else if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
2196                                die_errno("cannot open or read '%s'", read_from);
2197                        break;
2198                case S_IFLNK:
2199                        if (strbuf_readlink(&buf, read_from, st.st_size) < 0)
2200                                die_errno("cannot readlink '%s'", read_from);
2201                        break;
2202                default:
2203                        die("unsupported file type %s", read_from);
2204                }
2205        }
2206        else {
2207                /* Reading from stdin */
2208                mode = 0;
2209                if (strbuf_read(&buf, 0, 0) < 0)
2210                        die_errno("failed to read from stdin");
2211        }
2212        convert_to_git(path, buf.buf, buf.len, &buf, 0);
2213        origin->file.ptr = buf.buf;
2214        origin->file.size = buf.len;
2215        pretend_sha1_file(buf.buf, buf.len, OBJ_BLOB, origin->blob_sha1);
2216        commit->util = origin;
2217
2218        /*
2219         * Read the current index, replace the path entry with
2220         * origin->blob_sha1 without mucking with its mode or type
2221         * bits; we are not going to write this index out -- we just
2222         * want to run "diff-index --cached".
2223         */
2224        discard_cache();
2225        read_cache();
2226
2227        len = strlen(path);
2228        if (!mode) {
2229                int pos = cache_name_pos(path, len);
2230                if (0 <= pos)
2231                        mode = active_cache[pos]->ce_mode;
2232                else
2233                        /* Let's not bother reading from HEAD tree */
2234                        mode = S_IFREG | 0644;
2235        }
2236        size = cache_entry_size(len);
2237        ce = xcalloc(1, size);
2238        hashcpy(ce->sha1, origin->blob_sha1);
2239        memcpy(ce->name, path, len);
2240        ce->ce_flags = create_ce_flags(0);
2241        ce->ce_namelen = len;
2242        ce->ce_mode = create_ce_mode(mode);
2243        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE);
2244
2245        /*
2246         * We are not going to write this out, so this does not matter
2247         * right now, but someday we might optimize diff-index --cached
2248         * with cache-tree information.
2249         */
2250        cache_tree_invalidate_path(active_cache_tree, path);
2251
2252        return commit;
2253}
2254
2255static const char *prepare_final(struct scoreboard *sb)
2256{
2257        int i;
2258        const char *final_commit_name = NULL;
2259        struct rev_info *revs = sb->revs;
2260
2261        /*
2262         * There must be one and only one positive commit in the
2263         * revs->pending array.
2264         */
2265        for (i = 0; i < revs->pending.nr; i++) {
2266                struct object *obj = revs->pending.objects[i].item;
2267                if (obj->flags & UNINTERESTING)
2268                        continue;
2269                while (obj->type == OBJ_TAG)
2270                        obj = deref_tag(obj, NULL, 0);
2271                if (obj->type != OBJ_COMMIT)
2272                        die("Non commit %s?", revs->pending.objects[i].name);
2273                if (sb->final)
2274                        die("More than one commit to dig from %s and %s?",
2275                            revs->pending.objects[i].name,
2276                            final_commit_name);
2277                sb->final = (struct commit *) obj;
2278                final_commit_name = revs->pending.objects[i].name;
2279        }
2280        return final_commit_name;
2281}
2282
2283static const char *prepare_initial(struct scoreboard *sb)
2284{
2285        int i;
2286        const char *final_commit_name = NULL;
2287        struct rev_info *revs = sb->revs;
2288
2289        /*
2290         * There must be one and only one negative commit, and it must be
2291         * the boundary.
2292         */
2293        for (i = 0; i < revs->pending.nr; i++) {
2294                struct object *obj = revs->pending.objects[i].item;
2295                if (!(obj->flags & UNINTERESTING))
2296                        continue;
2297                while (obj->type == OBJ_TAG)
2298                        obj = deref_tag(obj, NULL, 0);
2299                if (obj->type != OBJ_COMMIT)
2300                        die("Non commit %s?", revs->pending.objects[i].name);
2301                if (sb->final)
2302                        die("More than one commit to dig down to %s and %s?",
2303                            revs->pending.objects[i].name,
2304                            final_commit_name);
2305                sb->final = (struct commit *) obj;
2306                final_commit_name = revs->pending.objects[i].name;
2307        }
2308        if (!final_commit_name)
2309                die("No commit to dig down to?");
2310        return final_commit_name;
2311}
2312
2313static int blame_copy_callback(const struct option *option, const char *arg, int unset)
2314{
2315        int *opt = option->value;
2316
2317        /*
2318         * -C enables copy from removed files;
2319         * -C -C enables copy from existing files, but only
2320         *       when blaming a new file;
2321         * -C -C -C enables copy from existing files for
2322         *          everybody
2323         */
2324        if (*opt & PICKAXE_BLAME_COPY_HARDER)
2325                *opt |= PICKAXE_BLAME_COPY_HARDEST;
2326        if (*opt & PICKAXE_BLAME_COPY)
2327                *opt |= PICKAXE_BLAME_COPY_HARDER;
2328        *opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;
2329
2330        if (arg)
2331                blame_copy_score = parse_score(arg);
2332        return 0;
2333}
2334
2335static int blame_move_callback(const struct option *option, const char *arg, int unset)
2336{
2337        int *opt = option->value;
2338
2339        *opt |= PICKAXE_BLAME_MOVE;
2340
2341        if (arg)
2342                blame_move_score = parse_score(arg);
2343        return 0;
2344}
2345
2346static int blame_bottomtop_callback(const struct option *option, const char *arg, int unset)
2347{
2348        const char **bottomtop = option->value;
2349        if (!arg)
2350                return -1;
2351        if (*bottomtop)
2352                die("More than one '-L n,m' option given");
2353        *bottomtop = arg;
2354        return 0;
2355}
2356
2357int cmd_blame(int argc, const char **argv, const char *prefix)
2358{
2359        struct rev_info revs;
2360        const char *path;
2361        struct scoreboard sb;
2362        struct origin *o;
2363        struct blame_entry *ent;
2364        long dashdash_pos, bottom, top, lno;
2365        const char *final_commit_name = NULL;
2366        enum object_type type;
2367
2368        static const char *bottomtop = NULL;
2369        static int output_option = 0, opt = 0;
2370        static int show_stats = 0;
2371        static const char *revs_file = NULL;
2372        static const char *contents_from = NULL;
2373        static const struct option options[] = {
2374                OPT_BOOLEAN(0, "incremental", &incremental, N_("Show blame entries as we find them, incrementally")),
2375                OPT_BOOLEAN('b', NULL, &blank_boundary, N_("Show blank SHA-1 for boundary commits (Default: off)")),
2376                OPT_BOOLEAN(0, "root", &show_root, N_("Do not treat root commits as boundaries (Default: off)")),
2377                OPT_BOOLEAN(0, "show-stats", &show_stats, N_("Show work cost statistics")),
2378                OPT_BIT(0, "score-debug", &output_option, N_("Show output score for blame entries"), OUTPUT_SHOW_SCORE),
2379                OPT_BIT('f', "show-name", &output_option, N_("Show original filename (Default: auto)"), OUTPUT_SHOW_NAME),
2380                OPT_BIT('n', "show-number", &output_option, N_("Show original linenumber (Default: off)"), OUTPUT_SHOW_NUMBER),
2381                OPT_BIT('p', "porcelain", &output_option, N_("Show in a format designed for machine consumption"), OUTPUT_PORCELAIN),
2382                OPT_BIT(0, "line-porcelain", &output_option, N_("Show porcelain format with per-line commit information"), OUTPUT_PORCELAIN|OUTPUT_LINE_PORCELAIN),
2383                OPT_BIT('c', NULL, &output_option, N_("Use the same output mode as git-annotate (Default: off)"), OUTPUT_ANNOTATE_COMPAT),
2384                OPT_BIT('t', NULL, &output_option, N_("Show raw timestamp (Default: off)"), OUTPUT_RAW_TIMESTAMP),
2385                OPT_BIT('l', NULL, &output_option, N_("Show long commit SHA1 (Default: off)"), OUTPUT_LONG_OBJECT_NAME),
2386                OPT_BIT('s', NULL, &output_option, N_("Suppress author name and timestamp (Default: off)"), OUTPUT_NO_AUTHOR),
2387                OPT_BIT('e', "show-email", &output_option, N_("Show author email instead of name (Default: off)"), OUTPUT_SHOW_EMAIL),
2388                OPT_BIT('w', NULL, &xdl_opts, N_("Ignore whitespace differences"), XDF_IGNORE_WHITESPACE),
2389                OPT_BIT(0, "minimal", &xdl_opts, N_("Spend extra cycles to find better match"), XDF_NEED_MINIMAL),
2390                OPT_STRING('S', NULL, &revs_file, N_("file"), N_("Use revisions from <file> instead of calling git-rev-list")),
2391                OPT_STRING(0, "contents", &contents_from, N_("file"), N_("Use <file>'s contents as the final image")),
2392                { OPTION_CALLBACK, 'C', NULL, &opt, N_("score"), N_("Find line copies within and across files"), PARSE_OPT_OPTARG, blame_copy_callback },
2393                { OPTION_CALLBACK, 'M', NULL, &opt, N_("score"), N_("Find line movements within and across files"), PARSE_OPT_OPTARG, blame_move_callback },
2394                OPT_CALLBACK('L', NULL, &bottomtop, N_("n,m"), N_("Process only line range n,m, counting from 1"), blame_bottomtop_callback),
2395                OPT__ABBREV(&abbrev),
2396                OPT_END()
2397        };
2398
2399        struct parse_opt_ctx_t ctx;
2400        int cmd_is_annotate = !strcmp(argv[0], "annotate");
2401
2402        git_config(git_blame_config, NULL);
2403        init_revisions(&revs, NULL);
2404        revs.date_mode = blame_date_mode;
2405        DIFF_OPT_SET(&revs.diffopt, ALLOW_TEXTCONV);
2406
2407        save_commit_buffer = 0;
2408        dashdash_pos = 0;
2409
2410        parse_options_start(&ctx, argc, argv, prefix, options,
2411                            PARSE_OPT_KEEP_DASHDASH | PARSE_OPT_KEEP_ARGV0);
2412        for (;;) {
2413                switch (parse_options_step(&ctx, options, blame_opt_usage)) {
2414                case PARSE_OPT_HELP:
2415                        exit(129);
2416                case PARSE_OPT_DONE:
2417                        if (ctx.argv[0])
2418                                dashdash_pos = ctx.cpidx;
2419                        goto parse_done;
2420                }
2421
2422                if (!strcmp(ctx.argv[0], "--reverse")) {
2423                        ctx.argv[0] = "--children";
2424                        reverse = 1;
2425                }
2426                parse_revision_opt(&revs, &ctx, options, blame_opt_usage);
2427        }
2428parse_done:
2429        argc = parse_options_end(&ctx);
2430
2431        if (0 < abbrev)
2432                /* one more abbrev length is needed for the boundary commit */
2433                abbrev++;
2434
2435        if (revs_file && read_ancestry(revs_file))
2436                die_errno("reading graft file '%s' failed", revs_file);
2437
2438        if (cmd_is_annotate) {
2439                output_option |= OUTPUT_ANNOTATE_COMPAT;
2440                blame_date_mode = DATE_ISO8601;
2441        } else {
2442                blame_date_mode = revs.date_mode;
2443        }
2444
2445        /* The maximum width used to show the dates */
2446        switch (blame_date_mode) {
2447        case DATE_RFC2822:
2448                blame_date_width = sizeof("Thu, 19 Oct 2006 16:00:04 -0700");
2449                break;
2450        case DATE_ISO8601:
2451                blame_date_width = sizeof("2006-10-19 16:00:04 -0700");
2452                break;
2453        case DATE_RAW:
2454                blame_date_width = sizeof("1161298804 -0700");
2455                break;
2456        case DATE_SHORT:
2457                blame_date_width = sizeof("2006-10-19");
2458                break;
2459        case DATE_RELATIVE:
2460                /* "normal" is used as the fallback for "relative" */
2461        case DATE_LOCAL:
2462        case DATE_NORMAL:
2463                blame_date_width = sizeof("Thu Oct 19 16:00:04 2006 -0700");
2464                break;
2465        }
2466        blame_date_width -= 1; /* strip the null */
2467
2468        if (DIFF_OPT_TST(&revs.diffopt, FIND_COPIES_HARDER))
2469                opt |= (PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE |
2470                        PICKAXE_BLAME_COPY_HARDER);
2471
2472        if (!blame_move_score)
2473                blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
2474        if (!blame_copy_score)
2475                blame_copy_score = BLAME_DEFAULT_COPY_SCORE;
2476
2477        /*
2478         * We have collected options unknown to us in argv[1..unk]
2479         * which are to be passed to revision machinery if we are
2480         * going to do the "bottom" processing.
2481         *
2482         * The remaining are:
2483         *
2484         * (1) if dashdash_pos != 0, it is either
2485         *     "blame [revisions] -- <path>" or
2486         *     "blame -- <path> <rev>"
2487         *
2488         * (2) otherwise, it is one of the two:
2489         *     "blame [revisions] <path>"
2490         *     "blame <path> <rev>"
2491         *
2492         * Note that we must strip out <path> from the arguments: we do not
2493         * want the path pruning but we may want "bottom" processing.
2494         */
2495        if (dashdash_pos) {
2496                switch (argc - dashdash_pos - 1) {
2497                case 2: /* (1b) */
2498                        if (argc != 4)
2499                                usage_with_options(blame_opt_usage, options);
2500                        /* reorder for the new way: <rev> -- <path> */
2501                        argv[1] = argv[3];
2502                        argv[3] = argv[2];
2503                        argv[2] = "--";
2504                        /* FALLTHROUGH */
2505                case 1: /* (1a) */
2506                        path = add_prefix(prefix, argv[--argc]);
2507                        argv[argc] = NULL;
2508                        break;
2509                default:
2510                        usage_with_options(blame_opt_usage, options);
2511                }
2512        } else {
2513                if (argc < 2)
2514                        usage_with_options(blame_opt_usage, options);
2515                path = add_prefix(prefix, argv[argc - 1]);
2516                if (argc == 3 && !has_string_in_work_tree(path)) { /* (2b) */
2517                        path = add_prefix(prefix, argv[1]);
2518                        argv[1] = argv[2];
2519                }
2520                argv[argc - 1] = "--";
2521
2522                setup_work_tree();
2523                if (!has_string_in_work_tree(path))
2524                        die_errno("cannot stat path '%s'", path);
2525        }
2526
2527        revs.disable_stdin = 1;
2528        setup_revisions(argc, argv, &revs, NULL);
2529        memset(&sb, 0, sizeof(sb));
2530
2531        sb.revs = &revs;
2532        if (!reverse)
2533                final_commit_name = prepare_final(&sb);
2534        else if (contents_from)
2535                die("--contents and --children do not blend well.");
2536        else
2537                final_commit_name = prepare_initial(&sb);
2538
2539        if (!sb.final) {
2540                /*
2541                 * "--not A B -- path" without anything positive;
2542                 * do not default to HEAD, but use the working tree
2543                 * or "--contents".
2544                 */
2545                setup_work_tree();
2546                sb.final = fake_working_tree_commit(&sb.revs->diffopt,
2547                                                    path, contents_from);
2548                add_pending_object(&revs, &(sb.final->object), ":");
2549        }
2550        else if (contents_from)
2551                die("Cannot use --contents with final commit object name");
2552
2553        /*
2554         * If we have bottom, this will mark the ancestors of the
2555         * bottom commits we would reach while traversing as
2556         * uninteresting.
2557         */
2558        if (prepare_revision_walk(&revs))
2559                die("revision walk setup failed");
2560
2561        if (is_null_sha1(sb.final->object.sha1)) {
2562                char *buf;
2563                o = sb.final->util;
2564                buf = xmalloc(o->file.size + 1);
2565                memcpy(buf, o->file.ptr, o->file.size + 1);
2566                sb.final_buf = buf;
2567                sb.final_buf_size = o->file.size;
2568        }
2569        else {
2570                o = get_origin(&sb, sb.final, path);
2571                if (fill_blob_sha1_and_mode(o))
2572                        die("no such path %s in %s", path, final_commit_name);
2573
2574                if (DIFF_OPT_TST(&sb.revs->diffopt, ALLOW_TEXTCONV) &&
2575                    textconv_object(path, o->mode, o->blob_sha1, 1, (char **) &sb.final_buf,
2576                                    &sb.final_buf_size))
2577                        ;
2578                else
2579                        sb.final_buf = read_sha1_file(o->blob_sha1, &type,
2580                                                      &sb.final_buf_size);
2581
2582                if (!sb.final_buf)
2583                        die("Cannot read blob %s for path %s",
2584                            sha1_to_hex(o->blob_sha1),
2585                            path);
2586        }
2587        num_read_blob++;
2588        lno = prepare_lines(&sb);
2589
2590        bottom = top = 0;
2591        if (bottomtop)
2592                prepare_blame_range(&sb, bottomtop, lno, &bottom, &top);
2593        if (bottom && top && top < bottom) {
2594                long tmp;
2595                tmp = top; top = bottom; bottom = tmp;
2596        }
2597        if (bottom < 1)
2598                bottom = 1;
2599        if (top < 1)
2600                top = lno;
2601        bottom--;
2602        if (lno < top || lno < bottom)
2603                die("file %s has only %lu lines", path, lno);
2604
2605        ent = xcalloc(1, sizeof(*ent));
2606        ent->lno = bottom;
2607        ent->num_lines = top - bottom;
2608        ent->suspect = o;
2609        ent->s_lno = bottom;
2610
2611        sb.ent = ent;
2612        sb.path = path;
2613
2614        read_mailmap(&mailmap, NULL);
2615
2616        if (!incremental)
2617                setup_pager();
2618
2619        assign_blame(&sb, opt);
2620
2621        if (incremental)
2622                return 0;
2623
2624        coalesce(&sb);
2625
2626        if (!(output_option & OUTPUT_PORCELAIN))
2627                find_alignment(&sb, &output_option);
2628
2629        output(&sb, output_option);
2630        free((void *)sb.final_buf);
2631        for (ent = sb.ent; ent; ) {
2632                struct blame_entry *e = ent->next;
2633                free(ent);
2634                ent = e;
2635        }
2636
2637        if (show_stats) {
2638                printf("num read blob: %d\n", num_read_blob);
2639                printf("num get patch: %d\n", num_get_patch);
2640                printf("num commits: %d\n", num_commits);
2641        }
2642        return 0;
2643}