diff.con commit diff --stat: add config option to limit graph width (df44483)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 400;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static int diff_stat_graph_width;
  35static int diff_dirstat_permille_default = 30;
  36static struct diff_options default_diff_options;
  37
  38static char diff_colors[][COLOR_MAXLEN] = {
  39        GIT_COLOR_RESET,
  40        GIT_COLOR_NORMAL,       /* PLAIN */
  41        GIT_COLOR_BOLD,         /* METAINFO */
  42        GIT_COLOR_CYAN,         /* FRAGINFO */
  43        GIT_COLOR_RED,          /* OLD */
  44        GIT_COLOR_GREEN,        /* NEW */
  45        GIT_COLOR_YELLOW,       /* COMMIT */
  46        GIT_COLOR_BG_RED,       /* WHITESPACE */
  47        GIT_COLOR_NORMAL,       /* FUNCINFO */
  48};
  49
  50static int parse_diff_color_slot(const char *var, int ofs)
  51{
  52        if (!strcasecmp(var+ofs, "plain"))
  53                return DIFF_PLAIN;
  54        if (!strcasecmp(var+ofs, "meta"))
  55                return DIFF_METAINFO;
  56        if (!strcasecmp(var+ofs, "frag"))
  57                return DIFF_FRAGINFO;
  58        if (!strcasecmp(var+ofs, "old"))
  59                return DIFF_FILE_OLD;
  60        if (!strcasecmp(var+ofs, "new"))
  61                return DIFF_FILE_NEW;
  62        if (!strcasecmp(var+ofs, "commit"))
  63                return DIFF_COMMIT;
  64        if (!strcasecmp(var+ofs, "whitespace"))
  65                return DIFF_WHITESPACE;
  66        if (!strcasecmp(var+ofs, "func"))
  67                return DIFF_FUNCINFO;
  68        return -1;
  69}
  70
  71static int parse_dirstat_params(struct diff_options *options, const char *params,
  72                                struct strbuf *errmsg)
  73{
  74        const char *p = params;
  75        int p_len, ret = 0;
  76
  77        while (*p) {
  78                p_len = strchrnul(p, ',') - p;
  79                if (!memcmp(p, "changes", p_len)) {
  80                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  81                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  82                } else if (!memcmp(p, "lines", p_len)) {
  83                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  84                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  85                } else if (!memcmp(p, "files", p_len)) {
  86                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  87                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  88                } else if (!memcmp(p, "noncumulative", p_len)) {
  89                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  90                } else if (!memcmp(p, "cumulative", p_len)) {
  91                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  92                } else if (isdigit(*p)) {
  93                        char *end;
  94                        int permille = strtoul(p, &end, 10) * 10;
  95                        if (*end == '.' && isdigit(*++end)) {
  96                                /* only use first digit */
  97                                permille += *end - '0';
  98                                /* .. and ignore any further digits */
  99                                while (isdigit(*++end))
 100                                        ; /* nothing */
 101                        }
 102                        if (end - p == p_len)
 103                                options->dirstat_permille = permille;
 104                        else {
 105                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%.*s'\n"),
 106                                            p_len, p);
 107                                ret++;
 108                        }
 109                } else {
 110                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%.*s'\n"),
 111                                    p_len, p);
 112                        ret++;
 113                }
 114
 115                p += p_len;
 116
 117                if (*p)
 118                        p++; /* more parameters, swallow separator */
 119        }
 120        return ret;
 121}
 122
 123static int git_config_rename(const char *var, const char *value)
 124{
 125        if (!value)
 126                return DIFF_DETECT_RENAME;
 127        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 128                return  DIFF_DETECT_COPY;
 129        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 130}
 131
 132/*
 133 * These are to give UI layer defaults.
 134 * The core-level commands such as git-diff-files should
 135 * never be affected by the setting of diff.renames
 136 * the user happens to have in the configuration file.
 137 */
 138int git_diff_ui_config(const char *var, const char *value, void *cb)
 139{
 140        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 141                diff_use_color_default = git_config_colorbool(var, value);
 142                return 0;
 143        }
 144        if (!strcmp(var, "diff.renames")) {
 145                diff_detect_rename_default = git_config_rename(var, value);
 146                return 0;
 147        }
 148        if (!strcmp(var, "diff.autorefreshindex")) {
 149                diff_auto_refresh_index = git_config_bool(var, value);
 150                return 0;
 151        }
 152        if (!strcmp(var, "diff.mnemonicprefix")) {
 153                diff_mnemonic_prefix = git_config_bool(var, value);
 154                return 0;
 155        }
 156        if (!strcmp(var, "diff.noprefix")) {
 157                diff_no_prefix = git_config_bool(var, value);
 158                return 0;
 159        }
 160        if (!strcmp(var, "diff.statgraphwidth")) {
 161                diff_stat_graph_width = git_config_int(var, value);
 162                return 0;
 163        }
 164        if (!strcmp(var, "diff.external"))
 165                return git_config_string(&external_diff_cmd_cfg, var, value);
 166        if (!strcmp(var, "diff.wordregex"))
 167                return git_config_string(&diff_word_regex_cfg, var, value);
 168
 169        if (!strcmp(var, "diff.ignoresubmodules"))
 170                handle_ignore_submodules_arg(&default_diff_options, value);
 171
 172        if (git_color_config(var, value, cb) < 0)
 173                return -1;
 174
 175        return git_diff_basic_config(var, value, cb);
 176}
 177
 178int git_diff_basic_config(const char *var, const char *value, void *cb)
 179{
 180        if (!strcmp(var, "diff.renamelimit")) {
 181                diff_rename_limit_default = git_config_int(var, value);
 182                return 0;
 183        }
 184
 185        switch (userdiff_config(var, value)) {
 186                case 0: break;
 187                case -1: return -1;
 188                default: return 0;
 189        }
 190
 191        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 192                int slot = parse_diff_color_slot(var, 11);
 193                if (slot < 0)
 194                        return 0;
 195                if (!value)
 196                        return config_error_nonbool(var);
 197                color_parse(value, var, diff_colors[slot]);
 198                return 0;
 199        }
 200
 201        /* like GNU diff's --suppress-blank-empty option  */
 202        if (!strcmp(var, "diff.suppressblankempty") ||
 203                        /* for backwards compatibility */
 204                        !strcmp(var, "diff.suppress-blank-empty")) {
 205                diff_suppress_blank_empty = git_config_bool(var, value);
 206                return 0;
 207        }
 208
 209        if (!strcmp(var, "diff.dirstat")) {
 210                struct strbuf errmsg = STRBUF_INIT;
 211                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 212                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 213                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 214                                errmsg.buf);
 215                strbuf_release(&errmsg);
 216                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 217                return 0;
 218        }
 219
 220        if (!prefixcmp(var, "submodule."))
 221                return parse_submodule_config_option(var, value);
 222
 223        return git_default_config(var, value, cb);
 224}
 225
 226static char *quote_two(const char *one, const char *two)
 227{
 228        int need_one = quote_c_style(one, NULL, NULL, 1);
 229        int need_two = quote_c_style(two, NULL, NULL, 1);
 230        struct strbuf res = STRBUF_INIT;
 231
 232        if (need_one + need_two) {
 233                strbuf_addch(&res, '"');
 234                quote_c_style(one, &res, NULL, 1);
 235                quote_c_style(two, &res, NULL, 1);
 236                strbuf_addch(&res, '"');
 237        } else {
 238                strbuf_addstr(&res, one);
 239                strbuf_addstr(&res, two);
 240        }
 241        return strbuf_detach(&res, NULL);
 242}
 243
 244static const char *external_diff(void)
 245{
 246        static const char *external_diff_cmd = NULL;
 247        static int done_preparing = 0;
 248
 249        if (done_preparing)
 250                return external_diff_cmd;
 251        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 252        if (!external_diff_cmd)
 253                external_diff_cmd = external_diff_cmd_cfg;
 254        done_preparing = 1;
 255        return external_diff_cmd;
 256}
 257
 258static struct diff_tempfile {
 259        const char *name; /* filename external diff should read from */
 260        char hex[41];
 261        char mode[10];
 262        char tmp_path[PATH_MAX];
 263} diff_temp[2];
 264
 265typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 266
 267struct emit_callback {
 268        int color_diff;
 269        unsigned ws_rule;
 270        int blank_at_eof_in_preimage;
 271        int blank_at_eof_in_postimage;
 272        int lno_in_preimage;
 273        int lno_in_postimage;
 274        sane_truncate_fn truncate;
 275        const char **label_path;
 276        struct diff_words_data *diff_words;
 277        struct diff_options *opt;
 278        int *found_changesp;
 279        struct strbuf *header;
 280};
 281
 282static int count_lines(const char *data, int size)
 283{
 284        int count, ch, completely_empty = 1, nl_just_seen = 0;
 285        count = 0;
 286        while (0 < size--) {
 287                ch = *data++;
 288                if (ch == '\n') {
 289                        count++;
 290                        nl_just_seen = 1;
 291                        completely_empty = 0;
 292                }
 293                else {
 294                        nl_just_seen = 0;
 295                        completely_empty = 0;
 296                }
 297        }
 298        if (completely_empty)
 299                return 0;
 300        if (!nl_just_seen)
 301                count++; /* no trailing newline */
 302        return count;
 303}
 304
 305static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 306{
 307        if (!DIFF_FILE_VALID(one)) {
 308                mf->ptr = (char *)""; /* does not matter */
 309                mf->size = 0;
 310                return 0;
 311        }
 312        else if (diff_populate_filespec(one, 0))
 313                return -1;
 314
 315        mf->ptr = one->data;
 316        mf->size = one->size;
 317        return 0;
 318}
 319
 320/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 321static unsigned long diff_filespec_size(struct diff_filespec *one)
 322{
 323        if (!DIFF_FILE_VALID(one))
 324                return 0;
 325        diff_populate_filespec(one, 1);
 326        return one->size;
 327}
 328
 329static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 330{
 331        char *ptr = mf->ptr;
 332        long size = mf->size;
 333        int cnt = 0;
 334
 335        if (!size)
 336                return cnt;
 337        ptr += size - 1; /* pointing at the very end */
 338        if (*ptr != '\n')
 339                ; /* incomplete line */
 340        else
 341                ptr--; /* skip the last LF */
 342        while (mf->ptr < ptr) {
 343                char *prev_eol;
 344                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 345                        if (*prev_eol == '\n')
 346                                break;
 347                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 348                        break;
 349                cnt++;
 350                ptr = prev_eol - 1;
 351        }
 352        return cnt;
 353}
 354
 355static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 356                               struct emit_callback *ecbdata)
 357{
 358        int l1, l2, at;
 359        unsigned ws_rule = ecbdata->ws_rule;
 360        l1 = count_trailing_blank(mf1, ws_rule);
 361        l2 = count_trailing_blank(mf2, ws_rule);
 362        if (l2 <= l1) {
 363                ecbdata->blank_at_eof_in_preimage = 0;
 364                ecbdata->blank_at_eof_in_postimage = 0;
 365                return;
 366        }
 367        at = count_lines(mf1->ptr, mf1->size);
 368        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 369
 370        at = count_lines(mf2->ptr, mf2->size);
 371        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 372}
 373
 374static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 375                        int first, const char *line, int len)
 376{
 377        int has_trailing_newline, has_trailing_carriage_return;
 378        int nofirst;
 379        FILE *file = o->file;
 380
 381        if (o->output_prefix) {
 382                struct strbuf *msg = NULL;
 383                msg = o->output_prefix(o, o->output_prefix_data);
 384                assert(msg);
 385                fwrite(msg->buf, msg->len, 1, file);
 386        }
 387
 388        if (len == 0) {
 389                has_trailing_newline = (first == '\n');
 390                has_trailing_carriage_return = (!has_trailing_newline &&
 391                                                (first == '\r'));
 392                nofirst = has_trailing_newline || has_trailing_carriage_return;
 393        } else {
 394                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 395                if (has_trailing_newline)
 396                        len--;
 397                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 398                if (has_trailing_carriage_return)
 399                        len--;
 400                nofirst = 0;
 401        }
 402
 403        if (len || !nofirst) {
 404                fputs(set, file);
 405                if (!nofirst)
 406                        fputc(first, file);
 407                fwrite(line, len, 1, file);
 408                fputs(reset, file);
 409        }
 410        if (has_trailing_carriage_return)
 411                fputc('\r', file);
 412        if (has_trailing_newline)
 413                fputc('\n', file);
 414}
 415
 416static void emit_line(struct diff_options *o, const char *set, const char *reset,
 417                      const char *line, int len)
 418{
 419        emit_line_0(o, set, reset, line[0], line+1, len-1);
 420}
 421
 422static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 423{
 424        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 425              ecbdata->blank_at_eof_in_preimage &&
 426              ecbdata->blank_at_eof_in_postimage &&
 427              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 428              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 429                return 0;
 430        return ws_blank_line(line, len, ecbdata->ws_rule);
 431}
 432
 433static void emit_add_line(const char *reset,
 434                          struct emit_callback *ecbdata,
 435                          const char *line, int len)
 436{
 437        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 438        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 439
 440        if (!*ws)
 441                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 442        else if (new_blank_line_at_eof(ecbdata, line, len))
 443                /* Blank line at EOF - paint '+' as well */
 444                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 445        else {
 446                /* Emit just the prefix, then the rest. */
 447                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 448                ws_check_emit(line, len, ecbdata->ws_rule,
 449                              ecbdata->opt->file, set, reset, ws);
 450        }
 451}
 452
 453static void emit_hunk_header(struct emit_callback *ecbdata,
 454                             const char *line, int len)
 455{
 456        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 457        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 458        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 459        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 460        static const char atat[2] = { '@', '@' };
 461        const char *cp, *ep;
 462        struct strbuf msgbuf = STRBUF_INIT;
 463        int org_len = len;
 464        int i = 1;
 465
 466        /*
 467         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 468         * it always is at least 10 bytes long.
 469         */
 470        if (len < 10 ||
 471            memcmp(line, atat, 2) ||
 472            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 473                emit_line(ecbdata->opt, plain, reset, line, len);
 474                return;
 475        }
 476        ep += 2; /* skip over @@ */
 477
 478        /* The hunk header in fraginfo color */
 479        strbuf_add(&msgbuf, frag, strlen(frag));
 480        strbuf_add(&msgbuf, line, ep - line);
 481        strbuf_add(&msgbuf, reset, strlen(reset));
 482
 483        /*
 484         * trailing "\r\n"
 485         */
 486        for ( ; i < 3; i++)
 487                if (line[len - i] == '\r' || line[len - i] == '\n')
 488                        len--;
 489
 490        /* blank before the func header */
 491        for (cp = ep; ep - line < len; ep++)
 492                if (*ep != ' ' && *ep != '\t')
 493                        break;
 494        if (ep != cp) {
 495                strbuf_add(&msgbuf, plain, strlen(plain));
 496                strbuf_add(&msgbuf, cp, ep - cp);
 497                strbuf_add(&msgbuf, reset, strlen(reset));
 498        }
 499
 500        if (ep < line + len) {
 501                strbuf_add(&msgbuf, func, strlen(func));
 502                strbuf_add(&msgbuf, ep, line + len - ep);
 503                strbuf_add(&msgbuf, reset, strlen(reset));
 504        }
 505
 506        strbuf_add(&msgbuf, line + len, org_len - len);
 507        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 508        strbuf_release(&msgbuf);
 509}
 510
 511static struct diff_tempfile *claim_diff_tempfile(void) {
 512        int i;
 513        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 514                if (!diff_temp[i].name)
 515                        return diff_temp + i;
 516        die("BUG: diff is failing to clean up its tempfiles");
 517}
 518
 519static int remove_tempfile_installed;
 520
 521static void remove_tempfile(void)
 522{
 523        int i;
 524        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 525                if (diff_temp[i].name == diff_temp[i].tmp_path)
 526                        unlink_or_warn(diff_temp[i].name);
 527                diff_temp[i].name = NULL;
 528        }
 529}
 530
 531static void remove_tempfile_on_signal(int signo)
 532{
 533        remove_tempfile();
 534        sigchain_pop(signo);
 535        raise(signo);
 536}
 537
 538static void print_line_count(FILE *file, int count)
 539{
 540        switch (count) {
 541        case 0:
 542                fprintf(file, "0,0");
 543                break;
 544        case 1:
 545                fprintf(file, "1");
 546                break;
 547        default:
 548                fprintf(file, "1,%d", count);
 549                break;
 550        }
 551}
 552
 553static void emit_rewrite_lines(struct emit_callback *ecb,
 554                               int prefix, const char *data, int size)
 555{
 556        const char *endp = NULL;
 557        static const char *nneof = " No newline at end of file\n";
 558        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 559        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 560
 561        while (0 < size) {
 562                int len;
 563
 564                endp = memchr(data, '\n', size);
 565                len = endp ? (endp - data + 1) : size;
 566                if (prefix != '+') {
 567                        ecb->lno_in_preimage++;
 568                        emit_line_0(ecb->opt, old, reset, '-',
 569                                    data, len);
 570                } else {
 571                        ecb->lno_in_postimage++;
 572                        emit_add_line(reset, ecb, data, len);
 573                }
 574                size -= len;
 575                data += len;
 576        }
 577        if (!endp) {
 578                const char *plain = diff_get_color(ecb->color_diff,
 579                                                   DIFF_PLAIN);
 580                emit_line_0(ecb->opt, plain, reset, '\\',
 581                            nneof, strlen(nneof));
 582        }
 583}
 584
 585static void emit_rewrite_diff(const char *name_a,
 586                              const char *name_b,
 587                              struct diff_filespec *one,
 588                              struct diff_filespec *two,
 589                              struct userdiff_driver *textconv_one,
 590                              struct userdiff_driver *textconv_two,
 591                              struct diff_options *o)
 592{
 593        int lc_a, lc_b;
 594        const char *name_a_tab, *name_b_tab;
 595        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 596        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 597        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 598        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 599        const char *a_prefix, *b_prefix;
 600        char *data_one, *data_two;
 601        size_t size_one, size_two;
 602        struct emit_callback ecbdata;
 603        char *line_prefix = "";
 604        struct strbuf *msgbuf;
 605
 606        if (o && o->output_prefix) {
 607                msgbuf = o->output_prefix(o, o->output_prefix_data);
 608                line_prefix = msgbuf->buf;
 609        }
 610
 611        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 612                a_prefix = o->b_prefix;
 613                b_prefix = o->a_prefix;
 614        } else {
 615                a_prefix = o->a_prefix;
 616                b_prefix = o->b_prefix;
 617        }
 618
 619        name_a += (*name_a == '/');
 620        name_b += (*name_b == '/');
 621        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 622        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 623
 624        strbuf_reset(&a_name);
 625        strbuf_reset(&b_name);
 626        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 627        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 628
 629        size_one = fill_textconv(textconv_one, one, &data_one);
 630        size_two = fill_textconv(textconv_two, two, &data_two);
 631
 632        memset(&ecbdata, 0, sizeof(ecbdata));
 633        ecbdata.color_diff = want_color(o->use_color);
 634        ecbdata.found_changesp = &o->found_changes;
 635        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 636        ecbdata.opt = o;
 637        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 638                mmfile_t mf1, mf2;
 639                mf1.ptr = (char *)data_one;
 640                mf2.ptr = (char *)data_two;
 641                mf1.size = size_one;
 642                mf2.size = size_two;
 643                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 644        }
 645        ecbdata.lno_in_preimage = 1;
 646        ecbdata.lno_in_postimage = 1;
 647
 648        lc_a = count_lines(data_one, size_one);
 649        lc_b = count_lines(data_two, size_two);
 650        fprintf(o->file,
 651                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 652                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 653                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 654                line_prefix, fraginfo);
 655        if (!o->irreversible_delete)
 656                print_line_count(o->file, lc_a);
 657        else
 658                fprintf(o->file, "?,?");
 659        fprintf(o->file, " +");
 660        print_line_count(o->file, lc_b);
 661        fprintf(o->file, " @@%s\n", reset);
 662        if (lc_a && !o->irreversible_delete)
 663                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 664        if (lc_b)
 665                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 666        if (textconv_one)
 667                free((char *)data_one);
 668        if (textconv_two)
 669                free((char *)data_two);
 670}
 671
 672struct diff_words_buffer {
 673        mmfile_t text;
 674        long alloc;
 675        struct diff_words_orig {
 676                const char *begin, *end;
 677        } *orig;
 678        int orig_nr, orig_alloc;
 679};
 680
 681static void diff_words_append(char *line, unsigned long len,
 682                struct diff_words_buffer *buffer)
 683{
 684        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 685        line++;
 686        len--;
 687        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 688        buffer->text.size += len;
 689        buffer->text.ptr[buffer->text.size] = '\0';
 690}
 691
 692struct diff_words_style_elem {
 693        const char *prefix;
 694        const char *suffix;
 695        const char *color; /* NULL; filled in by the setup code if
 696                            * color is enabled */
 697};
 698
 699struct diff_words_style {
 700        enum diff_words_type type;
 701        struct diff_words_style_elem new, old, ctx;
 702        const char *newline;
 703};
 704
 705static struct diff_words_style diff_words_styles[] = {
 706        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 707        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 708        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 709};
 710
 711struct diff_words_data {
 712        struct diff_words_buffer minus, plus;
 713        const char *current_plus;
 714        int last_minus;
 715        struct diff_options *opt;
 716        regex_t *word_regex;
 717        enum diff_words_type type;
 718        struct diff_words_style *style;
 719};
 720
 721static int fn_out_diff_words_write_helper(FILE *fp,
 722                                          struct diff_words_style_elem *st_el,
 723                                          const char *newline,
 724                                          size_t count, const char *buf,
 725                                          const char *line_prefix)
 726{
 727        int print = 0;
 728
 729        while (count) {
 730                char *p = memchr(buf, '\n', count);
 731                if (print)
 732                        fputs(line_prefix, fp);
 733                if (p != buf) {
 734                        if (st_el->color && fputs(st_el->color, fp) < 0)
 735                                return -1;
 736                        if (fputs(st_el->prefix, fp) < 0 ||
 737                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 738                            fputs(st_el->suffix, fp) < 0)
 739                                return -1;
 740                        if (st_el->color && *st_el->color
 741                            && fputs(GIT_COLOR_RESET, fp) < 0)
 742                                return -1;
 743                }
 744                if (!p)
 745                        return 0;
 746                if (fputs(newline, fp) < 0)
 747                        return -1;
 748                count -= p + 1 - buf;
 749                buf = p + 1;
 750                print = 1;
 751        }
 752        return 0;
 753}
 754
 755/*
 756 * '--color-words' algorithm can be described as:
 757 *
 758 *   1. collect a the minus/plus lines of a diff hunk, divided into
 759 *      minus-lines and plus-lines;
 760 *
 761 *   2. break both minus-lines and plus-lines into words and
 762 *      place them into two mmfile_t with one word for each line;
 763 *
 764 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 765 *
 766 * And for the common parts of the both file, we output the plus side text.
 767 * diff_words->current_plus is used to trace the current position of the plus file
 768 * which printed. diff_words->last_minus is used to trace the last minus word
 769 * printed.
 770 *
 771 * For '--graph' to work with '--color-words', we need to output the graph prefix
 772 * on each line of color words output. Generally, there are two conditions on
 773 * which we should output the prefix.
 774 *
 775 *   1. diff_words->last_minus == 0 &&
 776 *      diff_words->current_plus == diff_words->plus.text.ptr
 777 *
 778 *      that is: the plus text must start as a new line, and if there is no minus
 779 *      word printed, a graph prefix must be printed.
 780 *
 781 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 782 *      *(diff_words->current_plus - 1) == '\n'
 783 *
 784 *      that is: a graph prefix must be printed following a '\n'
 785 */
 786static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 787{
 788        if ((diff_words->last_minus == 0 &&
 789                diff_words->current_plus == diff_words->plus.text.ptr) ||
 790                (diff_words->current_plus > diff_words->plus.text.ptr &&
 791                *(diff_words->current_plus - 1) == '\n')) {
 792                return 1;
 793        } else {
 794                return 0;
 795        }
 796}
 797
 798static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 799{
 800        struct diff_words_data *diff_words = priv;
 801        struct diff_words_style *style = diff_words->style;
 802        int minus_first, minus_len, plus_first, plus_len;
 803        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 804        struct diff_options *opt = diff_words->opt;
 805        struct strbuf *msgbuf;
 806        char *line_prefix = "";
 807
 808        if (line[0] != '@' || parse_hunk_header(line, len,
 809                        &minus_first, &minus_len, &plus_first, &plus_len))
 810                return;
 811
 812        assert(opt);
 813        if (opt->output_prefix) {
 814                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 815                line_prefix = msgbuf->buf;
 816        }
 817
 818        /* POSIX requires that first be decremented by one if len == 0... */
 819        if (minus_len) {
 820                minus_begin = diff_words->minus.orig[minus_first].begin;
 821                minus_end =
 822                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 823        } else
 824                minus_begin = minus_end =
 825                        diff_words->minus.orig[minus_first].end;
 826
 827        if (plus_len) {
 828                plus_begin = diff_words->plus.orig[plus_first].begin;
 829                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 830        } else
 831                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 832
 833        if (color_words_output_graph_prefix(diff_words)) {
 834                fputs(line_prefix, diff_words->opt->file);
 835        }
 836        if (diff_words->current_plus != plus_begin) {
 837                fn_out_diff_words_write_helper(diff_words->opt->file,
 838                                &style->ctx, style->newline,
 839                                plus_begin - diff_words->current_plus,
 840                                diff_words->current_plus, line_prefix);
 841                if (*(plus_begin - 1) == '\n')
 842                        fputs(line_prefix, diff_words->opt->file);
 843        }
 844        if (minus_begin != minus_end) {
 845                fn_out_diff_words_write_helper(diff_words->opt->file,
 846                                &style->old, style->newline,
 847                                minus_end - minus_begin, minus_begin,
 848                                line_prefix);
 849        }
 850        if (plus_begin != plus_end) {
 851                fn_out_diff_words_write_helper(diff_words->opt->file,
 852                                &style->new, style->newline,
 853                                plus_end - plus_begin, plus_begin,
 854                                line_prefix);
 855        }
 856
 857        diff_words->current_plus = plus_end;
 858        diff_words->last_minus = minus_first;
 859}
 860
 861/* This function starts looking at *begin, and returns 0 iff a word was found. */
 862static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 863                int *begin, int *end)
 864{
 865        if (word_regex && *begin < buffer->size) {
 866                regmatch_t match[1];
 867                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 868                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 869                                        '\n', match[0].rm_eo - match[0].rm_so);
 870                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 871                        *begin += match[0].rm_so;
 872                        return *begin >= *end;
 873                }
 874                return -1;
 875        }
 876
 877        /* find the next word */
 878        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 879                (*begin)++;
 880        if (*begin >= buffer->size)
 881                return -1;
 882
 883        /* find the end of the word */
 884        *end = *begin + 1;
 885        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 886                (*end)++;
 887
 888        return 0;
 889}
 890
 891/*
 892 * This function splits the words in buffer->text, stores the list with
 893 * newline separator into out, and saves the offsets of the original words
 894 * in buffer->orig.
 895 */
 896static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 897                regex_t *word_regex)
 898{
 899        int i, j;
 900        long alloc = 0;
 901
 902        out->size = 0;
 903        out->ptr = NULL;
 904
 905        /* fake an empty "0th" word */
 906        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 907        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 908        buffer->orig_nr = 1;
 909
 910        for (i = 0; i < buffer->text.size; i++) {
 911                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 912                        return;
 913
 914                /* store original boundaries */
 915                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 916                                buffer->orig_alloc);
 917                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 918                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 919                buffer->orig_nr++;
 920
 921                /* store one word */
 922                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 923                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 924                out->ptr[out->size + j - i] = '\n';
 925                out->size += j - i + 1;
 926
 927                i = j - 1;
 928        }
 929}
 930
 931/* this executes the word diff on the accumulated buffers */
 932static void diff_words_show(struct diff_words_data *diff_words)
 933{
 934        xpparam_t xpp;
 935        xdemitconf_t xecfg;
 936        mmfile_t minus, plus;
 937        struct diff_words_style *style = diff_words->style;
 938
 939        struct diff_options *opt = diff_words->opt;
 940        struct strbuf *msgbuf;
 941        char *line_prefix = "";
 942
 943        assert(opt);
 944        if (opt->output_prefix) {
 945                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 946                line_prefix = msgbuf->buf;
 947        }
 948
 949        /* special case: only removal */
 950        if (!diff_words->plus.text.size) {
 951                fputs(line_prefix, diff_words->opt->file);
 952                fn_out_diff_words_write_helper(diff_words->opt->file,
 953                        &style->old, style->newline,
 954                        diff_words->minus.text.size,
 955                        diff_words->minus.text.ptr, line_prefix);
 956                diff_words->minus.text.size = 0;
 957                return;
 958        }
 959
 960        diff_words->current_plus = diff_words->plus.text.ptr;
 961        diff_words->last_minus = 0;
 962
 963        memset(&xpp, 0, sizeof(xpp));
 964        memset(&xecfg, 0, sizeof(xecfg));
 965        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 966        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 967        xpp.flags = 0;
 968        /* as only the hunk header will be parsed, we need a 0-context */
 969        xecfg.ctxlen = 0;
 970        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 971                      &xpp, &xecfg);
 972        free(minus.ptr);
 973        free(plus.ptr);
 974        if (diff_words->current_plus != diff_words->plus.text.ptr +
 975                        diff_words->plus.text.size) {
 976                if (color_words_output_graph_prefix(diff_words))
 977                        fputs(line_prefix, diff_words->opt->file);
 978                fn_out_diff_words_write_helper(diff_words->opt->file,
 979                        &style->ctx, style->newline,
 980                        diff_words->plus.text.ptr + diff_words->plus.text.size
 981                        - diff_words->current_plus, diff_words->current_plus,
 982                        line_prefix);
 983        }
 984        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 985}
 986
 987/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 988static void diff_words_flush(struct emit_callback *ecbdata)
 989{
 990        if (ecbdata->diff_words->minus.text.size ||
 991            ecbdata->diff_words->plus.text.size)
 992                diff_words_show(ecbdata->diff_words);
 993}
 994
 995static void free_diff_words_data(struct emit_callback *ecbdata)
 996{
 997        if (ecbdata->diff_words) {
 998                diff_words_flush(ecbdata);
 999                free (ecbdata->diff_words->minus.text.ptr);
1000                free (ecbdata->diff_words->minus.orig);
1001                free (ecbdata->diff_words->plus.text.ptr);
1002                free (ecbdata->diff_words->plus.orig);
1003                if (ecbdata->diff_words->word_regex) {
1004                        regfree(ecbdata->diff_words->word_regex);
1005                        free(ecbdata->diff_words->word_regex);
1006                }
1007                free(ecbdata->diff_words);
1008                ecbdata->diff_words = NULL;
1009        }
1010}
1011
1012const char *diff_get_color(int diff_use_color, enum color_diff ix)
1013{
1014        if (want_color(diff_use_color))
1015                return diff_colors[ix];
1016        return "";
1017}
1018
1019static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1020{
1021        const char *cp;
1022        unsigned long allot;
1023        size_t l = len;
1024
1025        if (ecb->truncate)
1026                return ecb->truncate(line, len);
1027        cp = line;
1028        allot = l;
1029        while (0 < l) {
1030                (void) utf8_width(&cp, &l);
1031                if (!cp)
1032                        break; /* truncated in the middle? */
1033        }
1034        return allot - l;
1035}
1036
1037static void find_lno(const char *line, struct emit_callback *ecbdata)
1038{
1039        const char *p;
1040        ecbdata->lno_in_preimage = 0;
1041        ecbdata->lno_in_postimage = 0;
1042        p = strchr(line, '-');
1043        if (!p)
1044                return; /* cannot happen */
1045        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1046        p = strchr(p, '+');
1047        if (!p)
1048                return; /* cannot happen */
1049        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1050}
1051
1052static void fn_out_consume(void *priv, char *line, unsigned long len)
1053{
1054        struct emit_callback *ecbdata = priv;
1055        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1056        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1057        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1058        struct diff_options *o = ecbdata->opt;
1059        char *line_prefix = "";
1060        struct strbuf *msgbuf;
1061
1062        if (o && o->output_prefix) {
1063                msgbuf = o->output_prefix(o, o->output_prefix_data);
1064                line_prefix = msgbuf->buf;
1065        }
1066
1067        if (ecbdata->header) {
1068                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1069                strbuf_reset(ecbdata->header);
1070                ecbdata->header = NULL;
1071        }
1072        *(ecbdata->found_changesp) = 1;
1073
1074        if (ecbdata->label_path[0]) {
1075                const char *name_a_tab, *name_b_tab;
1076
1077                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1078                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1079
1080                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1081                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1082                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1083                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1084                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1085        }
1086
1087        if (diff_suppress_blank_empty
1088            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1089                line[0] = '\n';
1090                len = 1;
1091        }
1092
1093        if (line[0] == '@') {
1094                if (ecbdata->diff_words)
1095                        diff_words_flush(ecbdata);
1096                len = sane_truncate_line(ecbdata, line, len);
1097                find_lno(line, ecbdata);
1098                emit_hunk_header(ecbdata, line, len);
1099                if (line[len-1] != '\n')
1100                        putc('\n', ecbdata->opt->file);
1101                return;
1102        }
1103
1104        if (len < 1) {
1105                emit_line(ecbdata->opt, reset, reset, line, len);
1106                if (ecbdata->diff_words
1107                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1108                        fputs("~\n", ecbdata->opt->file);
1109                return;
1110        }
1111
1112        if (ecbdata->diff_words) {
1113                if (line[0] == '-') {
1114                        diff_words_append(line, len,
1115                                          &ecbdata->diff_words->minus);
1116                        return;
1117                } else if (line[0] == '+') {
1118                        diff_words_append(line, len,
1119                                          &ecbdata->diff_words->plus);
1120                        return;
1121                } else if (!prefixcmp(line, "\\ ")) {
1122                        /*
1123                         * Eat the "no newline at eof" marker as if we
1124                         * saw a "+" or "-" line with nothing on it,
1125                         * and return without diff_words_flush() to
1126                         * defer processing. If this is the end of
1127                         * preimage, more "+" lines may come after it.
1128                         */
1129                        return;
1130                }
1131                diff_words_flush(ecbdata);
1132                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1133                        emit_line(ecbdata->opt, plain, reset, line, len);
1134                        fputs("~\n", ecbdata->opt->file);
1135                } else {
1136                        /*
1137                         * Skip the prefix character, if any.  With
1138                         * diff_suppress_blank_empty, there may be
1139                         * none.
1140                         */
1141                        if (line[0] != '\n') {
1142                              line++;
1143                              len--;
1144                        }
1145                        emit_line(ecbdata->opt, plain, reset, line, len);
1146                }
1147                return;
1148        }
1149
1150        if (line[0] != '+') {
1151                const char *color =
1152                        diff_get_color(ecbdata->color_diff,
1153                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1154                ecbdata->lno_in_preimage++;
1155                if (line[0] == ' ')
1156                        ecbdata->lno_in_postimage++;
1157                emit_line(ecbdata->opt, color, reset, line, len);
1158        } else {
1159                ecbdata->lno_in_postimage++;
1160                emit_add_line(reset, ecbdata, line + 1, len - 1);
1161        }
1162}
1163
1164static char *pprint_rename(const char *a, const char *b)
1165{
1166        const char *old = a;
1167        const char *new = b;
1168        struct strbuf name = STRBUF_INIT;
1169        int pfx_length, sfx_length;
1170        int len_a = strlen(a);
1171        int len_b = strlen(b);
1172        int a_midlen, b_midlen;
1173        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1174        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1175
1176        if (qlen_a || qlen_b) {
1177                quote_c_style(a, &name, NULL, 0);
1178                strbuf_addstr(&name, " => ");
1179                quote_c_style(b, &name, NULL, 0);
1180                return strbuf_detach(&name, NULL);
1181        }
1182
1183        /* Find common prefix */
1184        pfx_length = 0;
1185        while (*old && *new && *old == *new) {
1186                if (*old == '/')
1187                        pfx_length = old - a + 1;
1188                old++;
1189                new++;
1190        }
1191
1192        /* Find common suffix */
1193        old = a + len_a;
1194        new = b + len_b;
1195        sfx_length = 0;
1196        while (a <= old && b <= new && *old == *new) {
1197                if (*old == '/')
1198                        sfx_length = len_a - (old - a);
1199                old--;
1200                new--;
1201        }
1202
1203        /*
1204         * pfx{mid-a => mid-b}sfx
1205         * {pfx-a => pfx-b}sfx
1206         * pfx{sfx-a => sfx-b}
1207         * name-a => name-b
1208         */
1209        a_midlen = len_a - pfx_length - sfx_length;
1210        b_midlen = len_b - pfx_length - sfx_length;
1211        if (a_midlen < 0)
1212                a_midlen = 0;
1213        if (b_midlen < 0)
1214                b_midlen = 0;
1215
1216        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1217        if (pfx_length + sfx_length) {
1218                strbuf_add(&name, a, pfx_length);
1219                strbuf_addch(&name, '{');
1220        }
1221        strbuf_add(&name, a + pfx_length, a_midlen);
1222        strbuf_addstr(&name, " => ");
1223        strbuf_add(&name, b + pfx_length, b_midlen);
1224        if (pfx_length + sfx_length) {
1225                strbuf_addch(&name, '}');
1226                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1227        }
1228        return strbuf_detach(&name, NULL);
1229}
1230
1231struct diffstat_t {
1232        int nr;
1233        int alloc;
1234        struct diffstat_file {
1235                char *from_name;
1236                char *name;
1237                char *print_name;
1238                unsigned is_unmerged:1;
1239                unsigned is_binary:1;
1240                unsigned is_renamed:1;
1241                uintmax_t added, deleted;
1242        } **files;
1243};
1244
1245static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1246                                          const char *name_a,
1247                                          const char *name_b)
1248{
1249        struct diffstat_file *x;
1250        x = xcalloc(sizeof (*x), 1);
1251        if (diffstat->nr == diffstat->alloc) {
1252                diffstat->alloc = alloc_nr(diffstat->alloc);
1253                diffstat->files = xrealloc(diffstat->files,
1254                                diffstat->alloc * sizeof(x));
1255        }
1256        diffstat->files[diffstat->nr++] = x;
1257        if (name_b) {
1258                x->from_name = xstrdup(name_a);
1259                x->name = xstrdup(name_b);
1260                x->is_renamed = 1;
1261        }
1262        else {
1263                x->from_name = NULL;
1264                x->name = xstrdup(name_a);
1265        }
1266        return x;
1267}
1268
1269static void diffstat_consume(void *priv, char *line, unsigned long len)
1270{
1271        struct diffstat_t *diffstat = priv;
1272        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1273
1274        if (line[0] == '+')
1275                x->added++;
1276        else if (line[0] == '-')
1277                x->deleted++;
1278}
1279
1280const char mime_boundary_leader[] = "------------";
1281
1282static int scale_linear(int it, int width, int max_change)
1283{
1284        if (!it)
1285                return 0;
1286        /*
1287         * make sure that at least one '-' or '+' is printed if
1288         * there is any change to this path. The easiest way is to
1289         * scale linearly as if the alloted width is one column shorter
1290         * than it is, and then add 1 to the result.
1291         */
1292        return 1 + (it * (width - 1) / max_change);
1293}
1294
1295static void show_name(FILE *file,
1296                      const char *prefix, const char *name, int len)
1297{
1298        fprintf(file, " %s%-*s |", prefix, len, name);
1299}
1300
1301static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1302{
1303        if (cnt <= 0)
1304                return;
1305        fprintf(file, "%s", set);
1306        while (cnt--)
1307                putc(ch, file);
1308        fprintf(file, "%s", reset);
1309}
1310
1311static void fill_print_name(struct diffstat_file *file)
1312{
1313        char *pname;
1314
1315        if (file->print_name)
1316                return;
1317
1318        if (!file->is_renamed) {
1319                struct strbuf buf = STRBUF_INIT;
1320                if (quote_c_style(file->name, &buf, NULL, 0)) {
1321                        pname = strbuf_detach(&buf, NULL);
1322                } else {
1323                        pname = file->name;
1324                        strbuf_release(&buf);
1325                }
1326        } else {
1327                pname = pprint_rename(file->from_name, file->name);
1328        }
1329        file->print_name = pname;
1330}
1331
1332static void show_stats(struct diffstat_t *data, struct diff_options *options)
1333{
1334        int i, len, add, del, adds = 0, dels = 0;
1335        uintmax_t max_change = 0, max_len = 0;
1336        int total_files = data->nr;
1337        int width, name_width, graph_width, number_width = 4, count;
1338        const char *reset, *add_c, *del_c;
1339        const char *line_prefix = "";
1340        int extra_shown = 0;
1341        struct strbuf *msg = NULL;
1342
1343        if (data->nr == 0)
1344                return;
1345
1346        if (options->output_prefix) {
1347                msg = options->output_prefix(options, options->output_prefix_data);
1348                line_prefix = msg->buf;
1349        }
1350
1351        count = options->stat_count ? options->stat_count : data->nr;
1352
1353        reset = diff_get_color_opt(options, DIFF_RESET);
1354        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1355        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1356
1357        /*
1358         * Find the longest filename and max number of changes
1359         */
1360        for (i = 0; (i < count) && (i < data->nr); i++) {
1361                struct diffstat_file *file = data->files[i];
1362                uintmax_t change = file->added + file->deleted;
1363                if (!data->files[i]->is_renamed &&
1364                         (change == 0)) {
1365                        count++; /* not shown == room for one more */
1366                        continue;
1367                }
1368                fill_print_name(file);
1369                len = strlen(file->print_name);
1370                if (max_len < len)
1371                        max_len = len;
1372
1373                if (file->is_binary || file->is_unmerged)
1374                        continue;
1375                if (max_change < change)
1376                        max_change = change;
1377        }
1378        count = i; /* min(count, data->nr) */
1379
1380        /*
1381         * We have width = stat_width or term_columns() columns total.
1382         * We want a maximum of min(max_len, stat_name_width) for the name part.
1383         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1384         * We also need 1 for " " and 4 + decimal_width(max_change)
1385         * for " | NNNN " and one the empty column at the end, altogether
1386         * 6 + decimal_width(max_change).
1387         *
1388         * If there's not enough space, we will use the smaller of
1389         * stat_name_width (if set) and 5/8*width for the filename,
1390         * and the rest for constant elements + graph part, but no more
1391         * than stat_graph_width for the graph part.
1392         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1393         * for the standard terminal size).
1394         *
1395         * In other words: stat_width limits the maximum width, and
1396         * stat_name_width fixes the maximum width of the filename,
1397         * and is also used to divide available columns if there
1398         * aren't enough.
1399         */
1400
1401        if (options->stat_width == -1)
1402                width = term_columns();
1403        else
1404                width = options->stat_width ? options->stat_width : 80;
1405
1406        if (options->stat_graph_width == -1)
1407                options->stat_graph_width = diff_stat_graph_width;
1408
1409        /*
1410         * Guarantee 3/8*16==6 for the graph part
1411         * and 5/8*16==10 for the filename part
1412         */
1413        if (width < 16 + 6 + number_width)
1414                width = 16 + 6 + number_width;
1415
1416        /*
1417         * First assign sizes that are wanted, ignoring available width.
1418         */
1419        graph_width = (options->stat_graph_width &&
1420                       options->stat_graph_width < max_change) ?
1421                options->stat_graph_width : max_change;
1422        name_width = (options->stat_name_width > 0 &&
1423                      options->stat_name_width < max_len) ?
1424                options->stat_name_width : max_len;
1425
1426        /*
1427         * Adjust adjustable widths not to exceed maximum width
1428         */
1429        if (name_width + number_width + 6 + graph_width > width) {
1430                if (graph_width > width * 3/8 - number_width - 6)
1431                        graph_width = width * 3/8 - number_width - 6;
1432                if (options->stat_graph_width &&
1433                    graph_width > options->stat_graph_width)
1434                        graph_width = options->stat_graph_width;
1435                if (name_width > width - number_width - 6 - graph_width)
1436                        name_width = width - number_width - 6 - graph_width;
1437                else
1438                        graph_width = width - number_width - 6 - name_width;
1439        }
1440
1441        /*
1442         * From here name_width is the width of the name area,
1443         * and graph_width is the width of the graph area.
1444         * max_change is used to scale graph properly.
1445         */
1446        for (i = 0; i < count; i++) {
1447                const char *prefix = "";
1448                char *name = data->files[i]->print_name;
1449                uintmax_t added = data->files[i]->added;
1450                uintmax_t deleted = data->files[i]->deleted;
1451                int name_len;
1452
1453                if (!data->files[i]->is_renamed &&
1454                         (added + deleted == 0)) {
1455                        total_files--;
1456                        continue;
1457                }
1458                /*
1459                 * "scale" the filename
1460                 */
1461                len = name_width;
1462                name_len = strlen(name);
1463                if (name_width < name_len) {
1464                        char *slash;
1465                        prefix = "...";
1466                        len -= 3;
1467                        name += name_len - len;
1468                        slash = strchr(name, '/');
1469                        if (slash)
1470                                name = slash;
1471                }
1472
1473                if (data->files[i]->is_binary) {
1474                        fprintf(options->file, "%s", line_prefix);
1475                        show_name(options->file, prefix, name, len);
1476                        fprintf(options->file, "  Bin ");
1477                        fprintf(options->file, "%s%"PRIuMAX"%s",
1478                                del_c, deleted, reset);
1479                        fprintf(options->file, " -> ");
1480                        fprintf(options->file, "%s%"PRIuMAX"%s",
1481                                add_c, added, reset);
1482                        fprintf(options->file, " bytes");
1483                        fprintf(options->file, "\n");
1484                        continue;
1485                }
1486                else if (data->files[i]->is_unmerged) {
1487                        fprintf(options->file, "%s", line_prefix);
1488                        show_name(options->file, prefix, name, len);
1489                        fprintf(options->file, "  Unmerged\n");
1490                        continue;
1491                }
1492
1493                /*
1494                 * scale the add/delete
1495                 */
1496                add = added;
1497                del = deleted;
1498                adds += add;
1499                dels += del;
1500
1501                if (graph_width <= max_change) {
1502                        int total = add + del;
1503
1504                        total = scale_linear(add + del, graph_width, max_change);
1505                        if (total < 2 && add && del)
1506                                /* width >= 2 due to the sanity check */
1507                                total = 2;
1508                        if (add < del) {
1509                                add = scale_linear(add, graph_width, max_change);
1510                                del = total - add;
1511                        } else {
1512                                del = scale_linear(del, graph_width, max_change);
1513                                add = total - del;
1514                        }
1515                }
1516                fprintf(options->file, "%s", line_prefix);
1517                show_name(options->file, prefix, name, len);
1518                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1519                                added + deleted ? " " : "");
1520                show_graph(options->file, '+', add, add_c, reset);
1521                show_graph(options->file, '-', del, del_c, reset);
1522                fprintf(options->file, "\n");
1523        }
1524        for (i = count; i < data->nr; i++) {
1525                uintmax_t added = data->files[i]->added;
1526                uintmax_t deleted = data->files[i]->deleted;
1527                if (!data->files[i]->is_renamed &&
1528                         (added + deleted == 0)) {
1529                        total_files--;
1530                        continue;
1531                }
1532                adds += added;
1533                dels += deleted;
1534                if (!extra_shown)
1535                        fprintf(options->file, "%s ...\n", line_prefix);
1536                extra_shown = 1;
1537        }
1538        fprintf(options->file, "%s", line_prefix);
1539        fprintf(options->file,
1540               " %d files changed, %d insertions(+), %d deletions(-)\n",
1541               total_files, adds, dels);
1542}
1543
1544static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1545{
1546        int i, adds = 0, dels = 0, total_files = data->nr;
1547
1548        if (data->nr == 0)
1549                return;
1550
1551        for (i = 0; i < data->nr; i++) {
1552                if (!data->files[i]->is_binary &&
1553                    !data->files[i]->is_unmerged) {
1554                        int added = data->files[i]->added;
1555                        int deleted= data->files[i]->deleted;
1556                        if (!data->files[i]->is_renamed &&
1557                            (added + deleted == 0)) {
1558                                total_files--;
1559                        } else {
1560                                adds += added;
1561                                dels += deleted;
1562                        }
1563                }
1564        }
1565        if (options->output_prefix) {
1566                struct strbuf *msg = NULL;
1567                msg = options->output_prefix(options,
1568                                options->output_prefix_data);
1569                fprintf(options->file, "%s", msg->buf);
1570        }
1571        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1572               total_files, adds, dels);
1573}
1574
1575static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1576{
1577        int i;
1578
1579        if (data->nr == 0)
1580                return;
1581
1582        for (i = 0; i < data->nr; i++) {
1583                struct diffstat_file *file = data->files[i];
1584
1585                if (options->output_prefix) {
1586                        struct strbuf *msg = NULL;
1587                        msg = options->output_prefix(options,
1588                                        options->output_prefix_data);
1589                        fprintf(options->file, "%s", msg->buf);
1590                }
1591
1592                if (file->is_binary)
1593                        fprintf(options->file, "-\t-\t");
1594                else
1595                        fprintf(options->file,
1596                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1597                                file->added, file->deleted);
1598                if (options->line_termination) {
1599                        fill_print_name(file);
1600                        if (!file->is_renamed)
1601                                write_name_quoted(file->name, options->file,
1602                                                  options->line_termination);
1603                        else {
1604                                fputs(file->print_name, options->file);
1605                                putc(options->line_termination, options->file);
1606                        }
1607                } else {
1608                        if (file->is_renamed) {
1609                                putc('\0', options->file);
1610                                write_name_quoted(file->from_name, options->file, '\0');
1611                        }
1612                        write_name_quoted(file->name, options->file, '\0');
1613                }
1614        }
1615}
1616
1617struct dirstat_file {
1618        const char *name;
1619        unsigned long changed;
1620};
1621
1622struct dirstat_dir {
1623        struct dirstat_file *files;
1624        int alloc, nr, permille, cumulative;
1625};
1626
1627static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1628                unsigned long changed, const char *base, int baselen)
1629{
1630        unsigned long this_dir = 0;
1631        unsigned int sources = 0;
1632        const char *line_prefix = "";
1633        struct strbuf *msg = NULL;
1634
1635        if (opt->output_prefix) {
1636                msg = opt->output_prefix(opt, opt->output_prefix_data);
1637                line_prefix = msg->buf;
1638        }
1639
1640        while (dir->nr) {
1641                struct dirstat_file *f = dir->files;
1642                int namelen = strlen(f->name);
1643                unsigned long this;
1644                char *slash;
1645
1646                if (namelen < baselen)
1647                        break;
1648                if (memcmp(f->name, base, baselen))
1649                        break;
1650                slash = strchr(f->name + baselen, '/');
1651                if (slash) {
1652                        int newbaselen = slash + 1 - f->name;
1653                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1654                        sources++;
1655                } else {
1656                        this = f->changed;
1657                        dir->files++;
1658                        dir->nr--;
1659                        sources += 2;
1660                }
1661                this_dir += this;
1662        }
1663
1664        /*
1665         * We don't report dirstat's for
1666         *  - the top level
1667         *  - or cases where everything came from a single directory
1668         *    under this directory (sources == 1).
1669         */
1670        if (baselen && sources != 1) {
1671                if (this_dir) {
1672                        int permille = this_dir * 1000 / changed;
1673                        if (permille >= dir->permille) {
1674                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1675                                        permille / 10, permille % 10, baselen, base);
1676                                if (!dir->cumulative)
1677                                        return 0;
1678                        }
1679                }
1680        }
1681        return this_dir;
1682}
1683
1684static int dirstat_compare(const void *_a, const void *_b)
1685{
1686        const struct dirstat_file *a = _a;
1687        const struct dirstat_file *b = _b;
1688        return strcmp(a->name, b->name);
1689}
1690
1691static void show_dirstat(struct diff_options *options)
1692{
1693        int i;
1694        unsigned long changed;
1695        struct dirstat_dir dir;
1696        struct diff_queue_struct *q = &diff_queued_diff;
1697
1698        dir.files = NULL;
1699        dir.alloc = 0;
1700        dir.nr = 0;
1701        dir.permille = options->dirstat_permille;
1702        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1703
1704        changed = 0;
1705        for (i = 0; i < q->nr; i++) {
1706                struct diff_filepair *p = q->queue[i];
1707                const char *name;
1708                unsigned long copied, added, damage;
1709                int content_changed;
1710
1711                name = p->two->path ? p->two->path : p->one->path;
1712
1713                if (p->one->sha1_valid && p->two->sha1_valid)
1714                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1715                else
1716                        content_changed = 1;
1717
1718                if (!content_changed) {
1719                        /*
1720                         * The SHA1 has not changed, so pre-/post-content is
1721                         * identical. We can therefore skip looking at the
1722                         * file contents altogether.
1723                         */
1724                        damage = 0;
1725                        goto found_damage;
1726                }
1727
1728                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1729                        /*
1730                         * In --dirstat-by-file mode, we don't really need to
1731                         * look at the actual file contents at all.
1732                         * The fact that the SHA1 changed is enough for us to
1733                         * add this file to the list of results
1734                         * (with each file contributing equal damage).
1735                         */
1736                        damage = 1;
1737                        goto found_damage;
1738                }
1739
1740                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1741                        diff_populate_filespec(p->one, 0);
1742                        diff_populate_filespec(p->two, 0);
1743                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1744                                               &copied, &added);
1745                        diff_free_filespec_data(p->one);
1746                        diff_free_filespec_data(p->two);
1747                } else if (DIFF_FILE_VALID(p->one)) {
1748                        diff_populate_filespec(p->one, 1);
1749                        copied = added = 0;
1750                        diff_free_filespec_data(p->one);
1751                } else if (DIFF_FILE_VALID(p->two)) {
1752                        diff_populate_filespec(p->two, 1);
1753                        copied = 0;
1754                        added = p->two->size;
1755                        diff_free_filespec_data(p->two);
1756                } else
1757                        continue;
1758
1759                /*
1760                 * Original minus copied is the removed material,
1761                 * added is the new material.  They are both damages
1762                 * made to the preimage.
1763                 * If the resulting damage is zero, we know that
1764                 * diffcore_count_changes() considers the two entries to
1765                 * be identical, but since content_changed is true, we
1766                 * know that there must have been _some_ kind of change,
1767                 * so we force all entries to have damage > 0.
1768                 */
1769                damage = (p->one->size - copied) + added;
1770                if (!damage)
1771                        damage = 1;
1772
1773found_damage:
1774                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1775                dir.files[dir.nr].name = name;
1776                dir.files[dir.nr].changed = damage;
1777                changed += damage;
1778                dir.nr++;
1779        }
1780
1781        /* This can happen even with many files, if everything was renames */
1782        if (!changed)
1783                return;
1784
1785        /* Show all directories with more than x% of the changes */
1786        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1787        gather_dirstat(options, &dir, changed, "", 0);
1788}
1789
1790static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1791{
1792        int i;
1793        unsigned long changed;
1794        struct dirstat_dir dir;
1795
1796        if (data->nr == 0)
1797                return;
1798
1799        dir.files = NULL;
1800        dir.alloc = 0;
1801        dir.nr = 0;
1802        dir.permille = options->dirstat_permille;
1803        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1804
1805        changed = 0;
1806        for (i = 0; i < data->nr; i++) {
1807                struct diffstat_file *file = data->files[i];
1808                unsigned long damage = file->added + file->deleted;
1809                if (file->is_binary)
1810                        /*
1811                         * binary files counts bytes, not lines. Must find some
1812                         * way to normalize binary bytes vs. textual lines.
1813                         * The following heuristic assumes that there are 64
1814                         * bytes per "line".
1815                         * This is stupid and ugly, but very cheap...
1816                         */
1817                        damage = (damage + 63) / 64;
1818                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1819                dir.files[dir.nr].name = file->name;
1820                dir.files[dir.nr].changed = damage;
1821                changed += damage;
1822                dir.nr++;
1823        }
1824
1825        /* This can happen even with many files, if everything was renames */
1826        if (!changed)
1827                return;
1828
1829        /* Show all directories with more than x% of the changes */
1830        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1831        gather_dirstat(options, &dir, changed, "", 0);
1832}
1833
1834static void free_diffstat_info(struct diffstat_t *diffstat)
1835{
1836        int i;
1837        for (i = 0; i < diffstat->nr; i++) {
1838                struct diffstat_file *f = diffstat->files[i];
1839                if (f->name != f->print_name)
1840                        free(f->print_name);
1841                free(f->name);
1842                free(f->from_name);
1843                free(f);
1844        }
1845        free(diffstat->files);
1846}
1847
1848struct checkdiff_t {
1849        const char *filename;
1850        int lineno;
1851        int conflict_marker_size;
1852        struct diff_options *o;
1853        unsigned ws_rule;
1854        unsigned status;
1855};
1856
1857static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1858{
1859        char firstchar;
1860        int cnt;
1861
1862        if (len < marker_size + 1)
1863                return 0;
1864        firstchar = line[0];
1865        switch (firstchar) {
1866        case '=': case '>': case '<': case '|':
1867                break;
1868        default:
1869                return 0;
1870        }
1871        for (cnt = 1; cnt < marker_size; cnt++)
1872                if (line[cnt] != firstchar)
1873                        return 0;
1874        /* line[1] thru line[marker_size-1] are same as firstchar */
1875        if (len < marker_size + 1 || !isspace(line[marker_size]))
1876                return 0;
1877        return 1;
1878}
1879
1880static void checkdiff_consume(void *priv, char *line, unsigned long len)
1881{
1882        struct checkdiff_t *data = priv;
1883        int marker_size = data->conflict_marker_size;
1884        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1885        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1886        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1887        char *err;
1888        char *line_prefix = "";
1889        struct strbuf *msgbuf;
1890
1891        assert(data->o);
1892        if (data->o->output_prefix) {
1893                msgbuf = data->o->output_prefix(data->o,
1894                        data->o->output_prefix_data);
1895                line_prefix = msgbuf->buf;
1896        }
1897
1898        if (line[0] == '+') {
1899                unsigned bad;
1900                data->lineno++;
1901                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1902                        data->status |= 1;
1903                        fprintf(data->o->file,
1904                                "%s%s:%d: leftover conflict marker\n",
1905                                line_prefix, data->filename, data->lineno);
1906                }
1907                bad = ws_check(line + 1, len - 1, data->ws_rule);
1908                if (!bad)
1909                        return;
1910                data->status |= bad;
1911                err = whitespace_error_string(bad);
1912                fprintf(data->o->file, "%s%s:%d: %s.\n",
1913                        line_prefix, data->filename, data->lineno, err);
1914                free(err);
1915                emit_line(data->o, set, reset, line, 1);
1916                ws_check_emit(line + 1, len - 1, data->ws_rule,
1917                              data->o->file, set, reset, ws);
1918        } else if (line[0] == ' ') {
1919                data->lineno++;
1920        } else if (line[0] == '@') {
1921                char *plus = strchr(line, '+');
1922                if (plus)
1923                        data->lineno = strtol(plus, NULL, 10) - 1;
1924                else
1925                        die("invalid diff");
1926        }
1927}
1928
1929static unsigned char *deflate_it(char *data,
1930                                 unsigned long size,
1931                                 unsigned long *result_size)
1932{
1933        int bound;
1934        unsigned char *deflated;
1935        git_zstream stream;
1936
1937        memset(&stream, 0, sizeof(stream));
1938        git_deflate_init(&stream, zlib_compression_level);
1939        bound = git_deflate_bound(&stream, size);
1940        deflated = xmalloc(bound);
1941        stream.next_out = deflated;
1942        stream.avail_out = bound;
1943
1944        stream.next_in = (unsigned char *)data;
1945        stream.avail_in = size;
1946        while (git_deflate(&stream, Z_FINISH) == Z_OK)
1947                ; /* nothing */
1948        git_deflate_end(&stream);
1949        *result_size = stream.total_out;
1950        return deflated;
1951}
1952
1953static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1954{
1955        void *cp;
1956        void *delta;
1957        void *deflated;
1958        void *data;
1959        unsigned long orig_size;
1960        unsigned long delta_size;
1961        unsigned long deflate_size;
1962        unsigned long data_size;
1963
1964        /* We could do deflated delta, or we could do just deflated two,
1965         * whichever is smaller.
1966         */
1967        delta = NULL;
1968        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1969        if (one->size && two->size) {
1970                delta = diff_delta(one->ptr, one->size,
1971                                   two->ptr, two->size,
1972                                   &delta_size, deflate_size);
1973                if (delta) {
1974                        void *to_free = delta;
1975                        orig_size = delta_size;
1976                        delta = deflate_it(delta, delta_size, &delta_size);
1977                        free(to_free);
1978                }
1979        }
1980
1981        if (delta && delta_size < deflate_size) {
1982                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1983                free(deflated);
1984                data = delta;
1985                data_size = delta_size;
1986        }
1987        else {
1988                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1989                free(delta);
1990                data = deflated;
1991                data_size = deflate_size;
1992        }
1993
1994        /* emit data encoded in base85 */
1995        cp = data;
1996        while (data_size) {
1997                int bytes = (52 < data_size) ? 52 : data_size;
1998                char line[70];
1999                data_size -= bytes;
2000                if (bytes <= 26)
2001                        line[0] = bytes + 'A' - 1;
2002                else
2003                        line[0] = bytes - 26 + 'a' - 1;
2004                encode_85(line + 1, cp, bytes);
2005                cp = (char *) cp + bytes;
2006                fprintf(file, "%s", prefix);
2007                fputs(line, file);
2008                fputc('\n', file);
2009        }
2010        fprintf(file, "%s\n", prefix);
2011        free(data);
2012}
2013
2014static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2015{
2016        fprintf(file, "%sGIT binary patch\n", prefix);
2017        emit_binary_diff_body(file, one, two, prefix);
2018        emit_binary_diff_body(file, two, one, prefix);
2019}
2020
2021static void diff_filespec_load_driver(struct diff_filespec *one)
2022{
2023        /* Use already-loaded driver */
2024        if (one->driver)
2025                return;
2026
2027        if (S_ISREG(one->mode))
2028                one->driver = userdiff_find_by_path(one->path);
2029
2030        /* Fallback to default settings */
2031        if (!one->driver)
2032                one->driver = userdiff_find_by_name("default");
2033}
2034
2035int diff_filespec_is_binary(struct diff_filespec *one)
2036{
2037        if (one->is_binary == -1) {
2038                diff_filespec_load_driver(one);
2039                if (one->driver->binary != -1)
2040                        one->is_binary = one->driver->binary;
2041                else {
2042                        if (!one->data && DIFF_FILE_VALID(one))
2043                                diff_populate_filespec(one, 0);
2044                        if (one->data)
2045                                one->is_binary = buffer_is_binary(one->data,
2046                                                one->size);
2047                        if (one->is_binary == -1)
2048                                one->is_binary = 0;
2049                }
2050        }
2051        return one->is_binary;
2052}
2053
2054static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2055{
2056        diff_filespec_load_driver(one);
2057        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2058}
2059
2060static const char *userdiff_word_regex(struct diff_filespec *one)
2061{
2062        diff_filespec_load_driver(one);
2063        return one->driver->word_regex;
2064}
2065
2066void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2067{
2068        if (!options->a_prefix)
2069                options->a_prefix = a;
2070        if (!options->b_prefix)
2071                options->b_prefix = b;
2072}
2073
2074struct userdiff_driver *get_textconv(struct diff_filespec *one)
2075{
2076        if (!DIFF_FILE_VALID(one))
2077                return NULL;
2078
2079        diff_filespec_load_driver(one);
2080        return userdiff_get_textconv(one->driver);
2081}
2082
2083static void builtin_diff(const char *name_a,
2084                         const char *name_b,
2085                         struct diff_filespec *one,
2086                         struct diff_filespec *two,
2087                         const char *xfrm_msg,
2088                         int must_show_header,
2089                         struct diff_options *o,
2090                         int complete_rewrite)
2091{
2092        mmfile_t mf1, mf2;
2093        const char *lbl[2];
2094        char *a_one, *b_two;
2095        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2096        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2097        const char *a_prefix, *b_prefix;
2098        struct userdiff_driver *textconv_one = NULL;
2099        struct userdiff_driver *textconv_two = NULL;
2100        struct strbuf header = STRBUF_INIT;
2101        struct strbuf *msgbuf;
2102        char *line_prefix = "";
2103
2104        if (o->output_prefix) {
2105                msgbuf = o->output_prefix(o, o->output_prefix_data);
2106                line_prefix = msgbuf->buf;
2107        }
2108
2109        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2110                        (!one->mode || S_ISGITLINK(one->mode)) &&
2111                        (!two->mode || S_ISGITLINK(two->mode))) {
2112                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2113                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2114                show_submodule_summary(o->file, one ? one->path : two->path,
2115                                one->sha1, two->sha1, two->dirty_submodule,
2116                                del, add, reset);
2117                return;
2118        }
2119
2120        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2121                textconv_one = get_textconv(one);
2122                textconv_two = get_textconv(two);
2123        }
2124
2125        diff_set_mnemonic_prefix(o, "a/", "b/");
2126        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2127                a_prefix = o->b_prefix;
2128                b_prefix = o->a_prefix;
2129        } else {
2130                a_prefix = o->a_prefix;
2131                b_prefix = o->b_prefix;
2132        }
2133
2134        /* Never use a non-valid filename anywhere if at all possible */
2135        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2136        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2137
2138        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2139        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2140        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2141        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2142        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2143        if (lbl[0][0] == '/') {
2144                /* /dev/null */
2145                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2146                if (xfrm_msg)
2147                        strbuf_addstr(&header, xfrm_msg);
2148                must_show_header = 1;
2149        }
2150        else if (lbl[1][0] == '/') {
2151                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2152                if (xfrm_msg)
2153                        strbuf_addstr(&header, xfrm_msg);
2154                must_show_header = 1;
2155        }
2156        else {
2157                if (one->mode != two->mode) {
2158                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2159                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2160                        must_show_header = 1;
2161                }
2162                if (xfrm_msg)
2163                        strbuf_addstr(&header, xfrm_msg);
2164
2165                /*
2166                 * we do not run diff between different kind
2167                 * of objects.
2168                 */
2169                if ((one->mode ^ two->mode) & S_IFMT)
2170                        goto free_ab_and_return;
2171                if (complete_rewrite &&
2172                    (textconv_one || !diff_filespec_is_binary(one)) &&
2173                    (textconv_two || !diff_filespec_is_binary(two))) {
2174                        fprintf(o->file, "%s", header.buf);
2175                        strbuf_reset(&header);
2176                        emit_rewrite_diff(name_a, name_b, one, two,
2177                                                textconv_one, textconv_two, o);
2178                        o->found_changes = 1;
2179                        goto free_ab_and_return;
2180                }
2181        }
2182
2183        if (o->irreversible_delete && lbl[1][0] == '/') {
2184                fprintf(o->file, "%s", header.buf);
2185                strbuf_reset(&header);
2186                goto free_ab_and_return;
2187        } else if (!DIFF_OPT_TST(o, TEXT) &&
2188            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2189              (!textconv_two && diff_filespec_is_binary(two)) )) {
2190                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2191                        die("unable to read files to diff");
2192                /* Quite common confusing case */
2193                if (mf1.size == mf2.size &&
2194                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2195                        if (must_show_header)
2196                                fprintf(o->file, "%s", header.buf);
2197                        goto free_ab_and_return;
2198                }
2199                fprintf(o->file, "%s", header.buf);
2200                strbuf_reset(&header);
2201                if (DIFF_OPT_TST(o, BINARY))
2202                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2203                else
2204                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2205                                line_prefix, lbl[0], lbl[1]);
2206                o->found_changes = 1;
2207        } else {
2208                /* Crazy xdl interfaces.. */
2209                const char *diffopts = getenv("GIT_DIFF_OPTS");
2210                xpparam_t xpp;
2211                xdemitconf_t xecfg;
2212                struct emit_callback ecbdata;
2213                const struct userdiff_funcname *pe;
2214
2215                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2216                        fprintf(o->file, "%s", header.buf);
2217                        strbuf_reset(&header);
2218                }
2219
2220                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2221                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2222
2223                pe = diff_funcname_pattern(one);
2224                if (!pe)
2225                        pe = diff_funcname_pattern(two);
2226
2227                memset(&xpp, 0, sizeof(xpp));
2228                memset(&xecfg, 0, sizeof(xecfg));
2229                memset(&ecbdata, 0, sizeof(ecbdata));
2230                ecbdata.label_path = lbl;
2231                ecbdata.color_diff = want_color(o->use_color);
2232                ecbdata.found_changesp = &o->found_changes;
2233                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2234                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2235                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2236                ecbdata.opt = o;
2237                ecbdata.header = header.len ? &header : NULL;
2238                xpp.flags = o->xdl_opts;
2239                xecfg.ctxlen = o->context;
2240                xecfg.interhunkctxlen = o->interhunkcontext;
2241                xecfg.flags = XDL_EMIT_FUNCNAMES;
2242                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2243                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2244                if (pe)
2245                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2246                if (!diffopts)
2247                        ;
2248                else if (!prefixcmp(diffopts, "--unified="))
2249                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2250                else if (!prefixcmp(diffopts, "-u"))
2251                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2252                if (o->word_diff) {
2253                        int i;
2254
2255                        ecbdata.diff_words =
2256                                xcalloc(1, sizeof(struct diff_words_data));
2257                        ecbdata.diff_words->type = o->word_diff;
2258                        ecbdata.diff_words->opt = o;
2259                        if (!o->word_regex)
2260                                o->word_regex = userdiff_word_regex(one);
2261                        if (!o->word_regex)
2262                                o->word_regex = userdiff_word_regex(two);
2263                        if (!o->word_regex)
2264                                o->word_regex = diff_word_regex_cfg;
2265                        if (o->word_regex) {
2266                                ecbdata.diff_words->word_regex = (regex_t *)
2267                                        xmalloc(sizeof(regex_t));
2268                                if (regcomp(ecbdata.diff_words->word_regex,
2269                                                o->word_regex,
2270                                                REG_EXTENDED | REG_NEWLINE))
2271                                        die ("Invalid regular expression: %s",
2272                                                        o->word_regex);
2273                        }
2274                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2275                                if (o->word_diff == diff_words_styles[i].type) {
2276                                        ecbdata.diff_words->style =
2277                                                &diff_words_styles[i];
2278                                        break;
2279                                }
2280                        }
2281                        if (want_color(o->use_color)) {
2282                                struct diff_words_style *st = ecbdata.diff_words->style;
2283                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2284                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2285                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2286                        }
2287                }
2288                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2289                              &xpp, &xecfg);
2290                if (o->word_diff)
2291                        free_diff_words_data(&ecbdata);
2292                if (textconv_one)
2293                        free(mf1.ptr);
2294                if (textconv_two)
2295                        free(mf2.ptr);
2296                xdiff_clear_find_func(&xecfg);
2297        }
2298
2299 free_ab_and_return:
2300        strbuf_release(&header);
2301        diff_free_filespec_data(one);
2302        diff_free_filespec_data(two);
2303        free(a_one);
2304        free(b_two);
2305        return;
2306}
2307
2308static void builtin_diffstat(const char *name_a, const char *name_b,
2309                             struct diff_filespec *one,
2310                             struct diff_filespec *two,
2311                             struct diffstat_t *diffstat,
2312                             struct diff_options *o,
2313                             int complete_rewrite)
2314{
2315        mmfile_t mf1, mf2;
2316        struct diffstat_file *data;
2317
2318        data = diffstat_add(diffstat, name_a, name_b);
2319
2320        if (!one || !two) {
2321                data->is_unmerged = 1;
2322                return;
2323        }
2324
2325        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2326                data->is_binary = 1;
2327                data->added = diff_filespec_size(two);
2328                data->deleted = diff_filespec_size(one);
2329        }
2330
2331        else if (complete_rewrite) {
2332                diff_populate_filespec(one, 0);
2333                diff_populate_filespec(two, 0);
2334                data->deleted = count_lines(one->data, one->size);
2335                data->added = count_lines(two->data, two->size);
2336        }
2337
2338        else {
2339                /* Crazy xdl interfaces.. */
2340                xpparam_t xpp;
2341                xdemitconf_t xecfg;
2342
2343                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2344                        die("unable to read files to diff");
2345
2346                memset(&xpp, 0, sizeof(xpp));
2347                memset(&xecfg, 0, sizeof(xecfg));
2348                xpp.flags = o->xdl_opts;
2349                xecfg.ctxlen = o->context;
2350                xecfg.interhunkctxlen = o->interhunkcontext;
2351                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2352                              &xpp, &xecfg);
2353        }
2354
2355        diff_free_filespec_data(one);
2356        diff_free_filespec_data(two);
2357}
2358
2359static void builtin_checkdiff(const char *name_a, const char *name_b,
2360                              const char *attr_path,
2361                              struct diff_filespec *one,
2362                              struct diff_filespec *two,
2363                              struct diff_options *o)
2364{
2365        mmfile_t mf1, mf2;
2366        struct checkdiff_t data;
2367
2368        if (!two)
2369                return;
2370
2371        memset(&data, 0, sizeof(data));
2372        data.filename = name_b ? name_b : name_a;
2373        data.lineno = 0;
2374        data.o = o;
2375        data.ws_rule = whitespace_rule(attr_path);
2376        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2377
2378        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2379                die("unable to read files to diff");
2380
2381        /*
2382         * All the other codepaths check both sides, but not checking
2383         * the "old" side here is deliberate.  We are checking the newly
2384         * introduced changes, and as long as the "new" side is text, we
2385         * can and should check what it introduces.
2386         */
2387        if (diff_filespec_is_binary(two))
2388                goto free_and_return;
2389        else {
2390                /* Crazy xdl interfaces.. */
2391                xpparam_t xpp;
2392                xdemitconf_t xecfg;
2393
2394                memset(&xpp, 0, sizeof(xpp));
2395                memset(&xecfg, 0, sizeof(xecfg));
2396                xecfg.ctxlen = 1; /* at least one context line */
2397                xpp.flags = 0;
2398                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2399                              &xpp, &xecfg);
2400
2401                if (data.ws_rule & WS_BLANK_AT_EOF) {
2402                        struct emit_callback ecbdata;
2403                        int blank_at_eof;
2404
2405                        ecbdata.ws_rule = data.ws_rule;
2406                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2407                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2408
2409                        if (blank_at_eof) {
2410                                static char *err;
2411                                if (!err)
2412                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2413                                fprintf(o->file, "%s:%d: %s.\n",
2414                                        data.filename, blank_at_eof, err);
2415                                data.status = 1; /* report errors */
2416                        }
2417                }
2418        }
2419 free_and_return:
2420        diff_free_filespec_data(one);
2421        diff_free_filespec_data(two);
2422        if (data.status)
2423                DIFF_OPT_SET(o, CHECK_FAILED);
2424}
2425
2426struct diff_filespec *alloc_filespec(const char *path)
2427{
2428        int namelen = strlen(path);
2429        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2430
2431        memset(spec, 0, sizeof(*spec));
2432        spec->path = (char *)(spec + 1);
2433        memcpy(spec->path, path, namelen+1);
2434        spec->count = 1;
2435        spec->is_binary = -1;
2436        return spec;
2437}
2438
2439void free_filespec(struct diff_filespec *spec)
2440{
2441        if (!--spec->count) {
2442                diff_free_filespec_data(spec);
2443                free(spec);
2444        }
2445}
2446
2447void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2448                   unsigned short mode)
2449{
2450        if (mode) {
2451                spec->mode = canon_mode(mode);
2452                hashcpy(spec->sha1, sha1);
2453                spec->sha1_valid = !is_null_sha1(sha1);
2454        }
2455}
2456
2457/*
2458 * Given a name and sha1 pair, if the index tells us the file in
2459 * the work tree has that object contents, return true, so that
2460 * prepare_temp_file() does not have to inflate and extract.
2461 */
2462static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2463{
2464        struct cache_entry *ce;
2465        struct stat st;
2466        int pos, len;
2467
2468        /*
2469         * We do not read the cache ourselves here, because the
2470         * benchmark with my previous version that always reads cache
2471         * shows that it makes things worse for diff-tree comparing
2472         * two linux-2.6 kernel trees in an already checked out work
2473         * tree.  This is because most diff-tree comparisons deal with
2474         * only a small number of files, while reading the cache is
2475         * expensive for a large project, and its cost outweighs the
2476         * savings we get by not inflating the object to a temporary
2477         * file.  Practically, this code only helps when we are used
2478         * by diff-cache --cached, which does read the cache before
2479         * calling us.
2480         */
2481        if (!active_cache)
2482                return 0;
2483
2484        /* We want to avoid the working directory if our caller
2485         * doesn't need the data in a normal file, this system
2486         * is rather slow with its stat/open/mmap/close syscalls,
2487         * and the object is contained in a pack file.  The pack
2488         * is probably already open and will be faster to obtain
2489         * the data through than the working directory.  Loose
2490         * objects however would tend to be slower as they need
2491         * to be individually opened and inflated.
2492         */
2493        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2494                return 0;
2495
2496        len = strlen(name);
2497        pos = cache_name_pos(name, len);
2498        if (pos < 0)
2499                return 0;
2500        ce = active_cache[pos];
2501
2502        /*
2503         * This is not the sha1 we are looking for, or
2504         * unreusable because it is not a regular file.
2505         */
2506        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2507                return 0;
2508
2509        /*
2510         * If ce is marked as "assume unchanged", there is no
2511         * guarantee that work tree matches what we are looking for.
2512         */
2513        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2514                return 0;
2515
2516        /*
2517         * If ce matches the file in the work tree, we can reuse it.
2518         */
2519        if (ce_uptodate(ce) ||
2520            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2521                return 1;
2522
2523        return 0;
2524}
2525
2526static int populate_from_stdin(struct diff_filespec *s)
2527{
2528        struct strbuf buf = STRBUF_INIT;
2529        size_t size = 0;
2530
2531        if (strbuf_read(&buf, 0, 0) < 0)
2532                return error("error while reading from stdin %s",
2533                                     strerror(errno));
2534
2535        s->should_munmap = 0;
2536        s->data = strbuf_detach(&buf, &size);
2537        s->size = size;
2538        s->should_free = 1;
2539        return 0;
2540}
2541
2542static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2543{
2544        int len;
2545        char *data = xmalloc(100), *dirty = "";
2546
2547        /* Are we looking at the work tree? */
2548        if (s->dirty_submodule)
2549                dirty = "-dirty";
2550
2551        len = snprintf(data, 100,
2552                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2553        s->data = data;
2554        s->size = len;
2555        s->should_free = 1;
2556        if (size_only) {
2557                s->data = NULL;
2558                free(data);
2559        }
2560        return 0;
2561}
2562
2563/*
2564 * While doing rename detection and pickaxe operation, we may need to
2565 * grab the data for the blob (or file) for our own in-core comparison.
2566 * diff_filespec has data and size fields for this purpose.
2567 */
2568int diff_populate_filespec(struct diff_filespec *s, int size_only)
2569{
2570        int err = 0;
2571        if (!DIFF_FILE_VALID(s))
2572                die("internal error: asking to populate invalid file.");
2573        if (S_ISDIR(s->mode))
2574                return -1;
2575
2576        if (s->data)
2577                return 0;
2578
2579        if (size_only && 0 < s->size)
2580                return 0;
2581
2582        if (S_ISGITLINK(s->mode))
2583                return diff_populate_gitlink(s, size_only);
2584
2585        if (!s->sha1_valid ||
2586            reuse_worktree_file(s->path, s->sha1, 0)) {
2587                struct strbuf buf = STRBUF_INIT;
2588                struct stat st;
2589                int fd;
2590
2591                if (!strcmp(s->path, "-"))
2592                        return populate_from_stdin(s);
2593
2594                if (lstat(s->path, &st) < 0) {
2595                        if (errno == ENOENT) {
2596                        err_empty:
2597                                err = -1;
2598                        empty:
2599                                s->data = (char *)"";
2600                                s->size = 0;
2601                                return err;
2602                        }
2603                }
2604                s->size = xsize_t(st.st_size);
2605                if (!s->size)
2606                        goto empty;
2607                if (S_ISLNK(st.st_mode)) {
2608                        struct strbuf sb = STRBUF_INIT;
2609
2610                        if (strbuf_readlink(&sb, s->path, s->size))
2611                                goto err_empty;
2612                        s->size = sb.len;
2613                        s->data = strbuf_detach(&sb, NULL);
2614                        s->should_free = 1;
2615                        return 0;
2616                }
2617                if (size_only)
2618                        return 0;
2619                fd = open(s->path, O_RDONLY);
2620                if (fd < 0)
2621                        goto err_empty;
2622                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2623                close(fd);
2624                s->should_munmap = 1;
2625
2626                /*
2627                 * Convert from working tree format to canonical git format
2628                 */
2629                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2630                        size_t size = 0;
2631                        munmap(s->data, s->size);
2632                        s->should_munmap = 0;
2633                        s->data = strbuf_detach(&buf, &size);
2634                        s->size = size;
2635                        s->should_free = 1;
2636                }
2637        }
2638        else {
2639                enum object_type type;
2640                if (size_only) {
2641                        type = sha1_object_info(s->sha1, &s->size);
2642                        if (type < 0)
2643                                die("unable to read %s", sha1_to_hex(s->sha1));
2644                } else {
2645                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2646                        if (!s->data)
2647                                die("unable to read %s", sha1_to_hex(s->sha1));
2648                        s->should_free = 1;
2649                }
2650        }
2651        return 0;
2652}
2653
2654void diff_free_filespec_blob(struct diff_filespec *s)
2655{
2656        if (s->should_free)
2657                free(s->data);
2658        else if (s->should_munmap)
2659                munmap(s->data, s->size);
2660
2661        if (s->should_free || s->should_munmap) {
2662                s->should_free = s->should_munmap = 0;
2663                s->data = NULL;
2664        }
2665}
2666
2667void diff_free_filespec_data(struct diff_filespec *s)
2668{
2669        diff_free_filespec_blob(s);
2670        free(s->cnt_data);
2671        s->cnt_data = NULL;
2672}
2673
2674static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2675                           void *blob,
2676                           unsigned long size,
2677                           const unsigned char *sha1,
2678                           int mode)
2679{
2680        int fd;
2681        struct strbuf buf = STRBUF_INIT;
2682        struct strbuf template = STRBUF_INIT;
2683        char *path_dup = xstrdup(path);
2684        const char *base = basename(path_dup);
2685
2686        /* Generate "XXXXXX_basename.ext" */
2687        strbuf_addstr(&template, "XXXXXX_");
2688        strbuf_addstr(&template, base);
2689
2690        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2691                        strlen(base) + 1);
2692        if (fd < 0)
2693                die_errno("unable to create temp-file");
2694        if (convert_to_working_tree(path,
2695                        (const char *)blob, (size_t)size, &buf)) {
2696                blob = buf.buf;
2697                size = buf.len;
2698        }
2699        if (write_in_full(fd, blob, size) != size)
2700                die_errno("unable to write temp-file");
2701        close(fd);
2702        temp->name = temp->tmp_path;
2703        strcpy(temp->hex, sha1_to_hex(sha1));
2704        temp->hex[40] = 0;
2705        sprintf(temp->mode, "%06o", mode);
2706        strbuf_release(&buf);
2707        strbuf_release(&template);
2708        free(path_dup);
2709}
2710
2711static struct diff_tempfile *prepare_temp_file(const char *name,
2712                struct diff_filespec *one)
2713{
2714        struct diff_tempfile *temp = claim_diff_tempfile();
2715
2716        if (!DIFF_FILE_VALID(one)) {
2717        not_a_valid_file:
2718                /* A '-' entry produces this for file-2, and
2719                 * a '+' entry produces this for file-1.
2720                 */
2721                temp->name = "/dev/null";
2722                strcpy(temp->hex, ".");
2723                strcpy(temp->mode, ".");
2724                return temp;
2725        }
2726
2727        if (!remove_tempfile_installed) {
2728                atexit(remove_tempfile);
2729                sigchain_push_common(remove_tempfile_on_signal);
2730                remove_tempfile_installed = 1;
2731        }
2732
2733        if (!one->sha1_valid ||
2734            reuse_worktree_file(name, one->sha1, 1)) {
2735                struct stat st;
2736                if (lstat(name, &st) < 0) {
2737                        if (errno == ENOENT)
2738                                goto not_a_valid_file;
2739                        die_errno("stat(%s)", name);
2740                }
2741                if (S_ISLNK(st.st_mode)) {
2742                        struct strbuf sb = STRBUF_INIT;
2743                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2744                                die_errno("readlink(%s)", name);
2745                        prep_temp_blob(name, temp, sb.buf, sb.len,
2746                                       (one->sha1_valid ?
2747                                        one->sha1 : null_sha1),
2748                                       (one->sha1_valid ?
2749                                        one->mode : S_IFLNK));
2750                        strbuf_release(&sb);
2751                }
2752                else {
2753                        /* we can borrow from the file in the work tree */
2754                        temp->name = name;
2755                        if (!one->sha1_valid)
2756                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2757                        else
2758                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2759                        /* Even though we may sometimes borrow the
2760                         * contents from the work tree, we always want
2761                         * one->mode.  mode is trustworthy even when
2762                         * !(one->sha1_valid), as long as
2763                         * DIFF_FILE_VALID(one).
2764                         */
2765                        sprintf(temp->mode, "%06o", one->mode);
2766                }
2767                return temp;
2768        }
2769        else {
2770                if (diff_populate_filespec(one, 0))
2771                        die("cannot read data blob for %s", one->path);
2772                prep_temp_blob(name, temp, one->data, one->size,
2773                               one->sha1, one->mode);
2774        }
2775        return temp;
2776}
2777
2778/* An external diff command takes:
2779 *
2780 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2781 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2782 *
2783 */
2784static void run_external_diff(const char *pgm,
2785                              const char *name,
2786                              const char *other,
2787                              struct diff_filespec *one,
2788                              struct diff_filespec *two,
2789                              const char *xfrm_msg,
2790                              int complete_rewrite)
2791{
2792        const char *spawn_arg[10];
2793        int retval;
2794        const char **arg = &spawn_arg[0];
2795
2796        if (one && two) {
2797                struct diff_tempfile *temp_one, *temp_two;
2798                const char *othername = (other ? other : name);
2799                temp_one = prepare_temp_file(name, one);
2800                temp_two = prepare_temp_file(othername, two);
2801                *arg++ = pgm;
2802                *arg++ = name;
2803                *arg++ = temp_one->name;
2804                *arg++ = temp_one->hex;
2805                *arg++ = temp_one->mode;
2806                *arg++ = temp_two->name;
2807                *arg++ = temp_two->hex;
2808                *arg++ = temp_two->mode;
2809                if (other) {
2810                        *arg++ = other;
2811                        *arg++ = xfrm_msg;
2812                }
2813        } else {
2814                *arg++ = pgm;
2815                *arg++ = name;
2816        }
2817        *arg = NULL;
2818        fflush(NULL);
2819        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2820        remove_tempfile();
2821        if (retval) {
2822                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2823                exit(1);
2824        }
2825}
2826
2827static int similarity_index(struct diff_filepair *p)
2828{
2829        return p->score * 100 / MAX_SCORE;
2830}
2831
2832static void fill_metainfo(struct strbuf *msg,
2833                          const char *name,
2834                          const char *other,
2835                          struct diff_filespec *one,
2836                          struct diff_filespec *two,
2837                          struct diff_options *o,
2838                          struct diff_filepair *p,
2839                          int *must_show_header,
2840                          int use_color)
2841{
2842        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2843        const char *reset = diff_get_color(use_color, DIFF_RESET);
2844        struct strbuf *msgbuf;
2845        char *line_prefix = "";
2846
2847        *must_show_header = 1;
2848        if (o->output_prefix) {
2849                msgbuf = o->output_prefix(o, o->output_prefix_data);
2850                line_prefix = msgbuf->buf;
2851        }
2852        strbuf_init(msg, PATH_MAX * 2 + 300);
2853        switch (p->status) {
2854        case DIFF_STATUS_COPIED:
2855                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2856                            line_prefix, set, similarity_index(p));
2857                strbuf_addf(msg, "%s\n%s%scopy from ",
2858                            reset,  line_prefix, set);
2859                quote_c_style(name, msg, NULL, 0);
2860                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2861                quote_c_style(other, msg, NULL, 0);
2862                strbuf_addf(msg, "%s\n", reset);
2863                break;
2864        case DIFF_STATUS_RENAMED:
2865                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2866                            line_prefix, set, similarity_index(p));
2867                strbuf_addf(msg, "%s\n%s%srename from ",
2868                            reset, line_prefix, set);
2869                quote_c_style(name, msg, NULL, 0);
2870                strbuf_addf(msg, "%s\n%s%srename to ",
2871                            reset, line_prefix, set);
2872                quote_c_style(other, msg, NULL, 0);
2873                strbuf_addf(msg, "%s\n", reset);
2874                break;
2875        case DIFF_STATUS_MODIFIED:
2876                if (p->score) {
2877                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2878                                    line_prefix,
2879                                    set, similarity_index(p), reset);
2880                        break;
2881                }
2882                /* fallthru */
2883        default:
2884                *must_show_header = 0;
2885        }
2886        if (one && two && hashcmp(one->sha1, two->sha1)) {
2887                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2888
2889                if (DIFF_OPT_TST(o, BINARY)) {
2890                        mmfile_t mf;
2891                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2892                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2893                                abbrev = 40;
2894                }
2895                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2896                            find_unique_abbrev(one->sha1, abbrev));
2897                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2898                if (one->mode == two->mode)
2899                        strbuf_addf(msg, " %06o", one->mode);
2900                strbuf_addf(msg, "%s\n", reset);
2901        }
2902}
2903
2904static void run_diff_cmd(const char *pgm,
2905                         const char *name,
2906                         const char *other,
2907                         const char *attr_path,
2908                         struct diff_filespec *one,
2909                         struct diff_filespec *two,
2910                         struct strbuf *msg,
2911                         struct diff_options *o,
2912                         struct diff_filepair *p)
2913{
2914        const char *xfrm_msg = NULL;
2915        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2916        int must_show_header = 0;
2917
2918        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2919                pgm = NULL;
2920        else {
2921                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2922                if (drv && drv->external)
2923                        pgm = drv->external;
2924        }
2925
2926        if (msg) {
2927                /*
2928                 * don't use colors when the header is intended for an
2929                 * external diff driver
2930                 */
2931                fill_metainfo(msg, name, other, one, two, o, p,
2932                              &must_show_header,
2933                              want_color(o->use_color) && !pgm);
2934                xfrm_msg = msg->len ? msg->buf : NULL;
2935        }
2936
2937        if (pgm) {
2938                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2939                                  complete_rewrite);
2940                return;
2941        }
2942        if (one && two)
2943                builtin_diff(name, other ? other : name,
2944                             one, two, xfrm_msg, must_show_header,
2945                             o, complete_rewrite);
2946        else
2947                fprintf(o->file, "* Unmerged path %s\n", name);
2948}
2949
2950static void diff_fill_sha1_info(struct diff_filespec *one)
2951{
2952        if (DIFF_FILE_VALID(one)) {
2953                if (!one->sha1_valid) {
2954                        struct stat st;
2955                        if (!strcmp(one->path, "-")) {
2956                                hashcpy(one->sha1, null_sha1);
2957                                return;
2958                        }
2959                        if (lstat(one->path, &st) < 0)
2960                                die_errno("stat '%s'", one->path);
2961                        if (index_path(one->sha1, one->path, &st, 0))
2962                                die("cannot hash %s", one->path);
2963                }
2964        }
2965        else
2966                hashclr(one->sha1);
2967}
2968
2969static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2970{
2971        /* Strip the prefix but do not molest /dev/null and absolute paths */
2972        if (*namep && **namep != '/') {
2973                *namep += prefix_length;
2974                if (**namep == '/')
2975                        ++*namep;
2976        }
2977        if (*otherp && **otherp != '/') {
2978                *otherp += prefix_length;
2979                if (**otherp == '/')
2980                        ++*otherp;
2981        }
2982}
2983
2984static void run_diff(struct diff_filepair *p, struct diff_options *o)
2985{
2986        const char *pgm = external_diff();
2987        struct strbuf msg;
2988        struct diff_filespec *one = p->one;
2989        struct diff_filespec *two = p->two;
2990        const char *name;
2991        const char *other;
2992        const char *attr_path;
2993
2994        name  = p->one->path;
2995        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2996        attr_path = name;
2997        if (o->prefix_length)
2998                strip_prefix(o->prefix_length, &name, &other);
2999
3000        if (DIFF_PAIR_UNMERGED(p)) {
3001                run_diff_cmd(pgm, name, NULL, attr_path,
3002                             NULL, NULL, NULL, o, p);
3003                return;
3004        }
3005
3006        diff_fill_sha1_info(one);
3007        diff_fill_sha1_info(two);
3008
3009        if (!pgm &&
3010            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3011            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3012                /*
3013                 * a filepair that changes between file and symlink
3014                 * needs to be split into deletion and creation.
3015                 */
3016                struct diff_filespec *null = alloc_filespec(two->path);
3017                run_diff_cmd(NULL, name, other, attr_path,
3018                             one, null, &msg, o, p);
3019                free(null);
3020                strbuf_release(&msg);
3021
3022                null = alloc_filespec(one->path);
3023                run_diff_cmd(NULL, name, other, attr_path,
3024                             null, two, &msg, o, p);
3025                free(null);
3026        }
3027        else
3028                run_diff_cmd(pgm, name, other, attr_path,
3029                             one, two, &msg, o, p);
3030
3031        strbuf_release(&msg);
3032}
3033
3034static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3035                         struct diffstat_t *diffstat)
3036{
3037        const char *name;
3038        const char *other;
3039        int complete_rewrite = 0;
3040
3041        if (DIFF_PAIR_UNMERGED(p)) {
3042                /* unmerged */
3043                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3044                return;
3045        }
3046
3047        name = p->one->path;
3048        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3049
3050        if (o->prefix_length)
3051                strip_prefix(o->prefix_length, &name, &other);
3052
3053        diff_fill_sha1_info(p->one);
3054        diff_fill_sha1_info(p->two);
3055
3056        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3057                complete_rewrite = 1;
3058        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3059}
3060
3061static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3062{
3063        const char *name;
3064        const char *other;
3065        const char *attr_path;
3066
3067        if (DIFF_PAIR_UNMERGED(p)) {
3068                /* unmerged */
3069                return;
3070        }
3071
3072        name = p->one->path;
3073        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3074        attr_path = other ? other : name;
3075
3076        if (o->prefix_length)
3077                strip_prefix(o->prefix_length, &name, &other);
3078
3079        diff_fill_sha1_info(p->one);
3080        diff_fill_sha1_info(p->two);
3081
3082        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3083}
3084
3085void diff_setup(struct diff_options *options)
3086{
3087        memcpy(options, &default_diff_options, sizeof(*options));
3088
3089        options->file = stdout;
3090
3091        options->line_termination = '\n';
3092        options->break_opt = -1;
3093        options->rename_limit = -1;
3094        options->dirstat_permille = diff_dirstat_permille_default;
3095        options->context = 3;
3096
3097        options->change = diff_change;
3098        options->add_remove = diff_addremove;
3099        options->use_color = diff_use_color_default;
3100        options->detect_rename = diff_detect_rename_default;
3101
3102        if (diff_no_prefix) {
3103                options->a_prefix = options->b_prefix = "";
3104        } else if (!diff_mnemonic_prefix) {
3105                options->a_prefix = "a/";
3106                options->b_prefix = "b/";
3107        }
3108}
3109
3110int diff_setup_done(struct diff_options *options)
3111{
3112        int count = 0;
3113
3114        if (options->output_format & DIFF_FORMAT_NAME)
3115                count++;
3116        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3117                count++;
3118        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3119                count++;
3120        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3121                count++;
3122        if (count > 1)
3123                die("--name-only, --name-status, --check and -s are mutually exclusive");
3124
3125        /*
3126         * Most of the time we can say "there are changes"
3127         * only by checking if there are changed paths, but
3128         * --ignore-whitespace* options force us to look
3129         * inside contents.
3130         */
3131
3132        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3133            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3134            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3135                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3136        else
3137                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3138
3139        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3140                options->detect_rename = DIFF_DETECT_COPY;
3141
3142        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3143                options->prefix = NULL;
3144        if (options->prefix)
3145                options->prefix_length = strlen(options->prefix);
3146        else
3147                options->prefix_length = 0;
3148
3149        if (options->output_format & (DIFF_FORMAT_NAME |
3150                                      DIFF_FORMAT_NAME_STATUS |
3151                                      DIFF_FORMAT_CHECKDIFF |
3152                                      DIFF_FORMAT_NO_OUTPUT))
3153                options->output_format &= ~(DIFF_FORMAT_RAW |
3154                                            DIFF_FORMAT_NUMSTAT |
3155                                            DIFF_FORMAT_DIFFSTAT |
3156                                            DIFF_FORMAT_SHORTSTAT |
3157                                            DIFF_FORMAT_DIRSTAT |
3158                                            DIFF_FORMAT_SUMMARY |
3159                                            DIFF_FORMAT_PATCH);
3160
3161        /*
3162         * These cases always need recursive; we do not drop caller-supplied
3163         * recursive bits for other formats here.
3164         */
3165        if (options->output_format & (DIFF_FORMAT_PATCH |
3166                                      DIFF_FORMAT_NUMSTAT |
3167                                      DIFF_FORMAT_DIFFSTAT |
3168                                      DIFF_FORMAT_SHORTSTAT |
3169                                      DIFF_FORMAT_DIRSTAT |
3170                                      DIFF_FORMAT_SUMMARY |
3171                                      DIFF_FORMAT_CHECKDIFF))
3172                DIFF_OPT_SET(options, RECURSIVE);
3173        /*
3174         * Also pickaxe would not work very well if you do not say recursive
3175         */
3176        if (options->pickaxe)
3177                DIFF_OPT_SET(options, RECURSIVE);
3178        /*
3179         * When patches are generated, submodules diffed against the work tree
3180         * must be checked for dirtiness too so it can be shown in the output
3181         */
3182        if (options->output_format & DIFF_FORMAT_PATCH)
3183                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3184
3185        if (options->detect_rename && options->rename_limit < 0)
3186                options->rename_limit = diff_rename_limit_default;
3187        if (options->setup & DIFF_SETUP_USE_CACHE) {
3188                if (!active_cache)
3189                        /* read-cache does not die even when it fails
3190                         * so it is safe for us to do this here.  Also
3191                         * it does not smudge active_cache or active_nr
3192                         * when it fails, so we do not have to worry about
3193                         * cleaning it up ourselves either.
3194                         */
3195                        read_cache();
3196        }
3197        if (options->abbrev <= 0 || 40 < options->abbrev)
3198                options->abbrev = 40; /* full */
3199
3200        /*
3201         * It does not make sense to show the first hit we happened
3202         * to have found.  It does not make sense not to return with
3203         * exit code in such a case either.
3204         */
3205        if (DIFF_OPT_TST(options, QUICK)) {
3206                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3207                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3208        }
3209
3210        return 0;
3211}
3212
3213static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3214{
3215        char c, *eq;
3216        int len;
3217
3218        if (*arg != '-')
3219                return 0;
3220        c = *++arg;
3221        if (!c)
3222                return 0;
3223        if (c == arg_short) {
3224                c = *++arg;
3225                if (!c)
3226                        return 1;
3227                if (val && isdigit(c)) {
3228                        char *end;
3229                        int n = strtoul(arg, &end, 10);
3230                        if (*end)
3231                                return 0;
3232                        *val = n;
3233                        return 1;
3234                }
3235                return 0;
3236        }
3237        if (c != '-')
3238                return 0;
3239        arg++;
3240        eq = strchr(arg, '=');
3241        if (eq)
3242                len = eq - arg;
3243        else
3244                len = strlen(arg);
3245        if (!len || strncmp(arg, arg_long, len))
3246                return 0;
3247        if (eq) {
3248                int n;
3249                char *end;
3250                if (!isdigit(*++eq))
3251                        return 0;
3252                n = strtoul(eq, &end, 10);
3253                if (*end)
3254                        return 0;
3255                *val = n;
3256        }
3257        return 1;
3258}
3259
3260static int diff_scoreopt_parse(const char *opt);
3261
3262static inline int short_opt(char opt, const char **argv,
3263                            const char **optarg)
3264{
3265        const char *arg = argv[0];
3266        if (arg[0] != '-' || arg[1] != opt)
3267                return 0;
3268        if (arg[2] != '\0') {
3269                *optarg = arg + 2;
3270                return 1;
3271        }
3272        if (!argv[1])
3273                die("Option '%c' requires a value", opt);
3274        *optarg = argv[1];
3275        return 2;
3276}
3277
3278int parse_long_opt(const char *opt, const char **argv,
3279                   const char **optarg)
3280{
3281        const char *arg = argv[0];
3282        if (arg[0] != '-' || arg[1] != '-')
3283                return 0;
3284        arg += strlen("--");
3285        if (prefixcmp(arg, opt))
3286                return 0;
3287        arg += strlen(opt);
3288        if (*arg == '=') { /* sticked form: --option=value */
3289                *optarg = arg + 1;
3290                return 1;
3291        }
3292        if (*arg != '\0')
3293                return 0;
3294        /* separate form: --option value */
3295        if (!argv[1])
3296                die("Option '--%s' requires a value", opt);
3297        *optarg = argv[1];
3298        return 2;
3299}
3300
3301static int stat_opt(struct diff_options *options, const char **av)
3302{
3303        const char *arg = av[0];
3304        char *end;
3305        int width = options->stat_width;
3306        int name_width = options->stat_name_width;
3307        int graph_width = options->stat_graph_width;
3308        int count = options->stat_count;
3309        int argcount = 1;
3310
3311        arg += strlen("--stat");
3312        end = (char *)arg;
3313
3314        switch (*arg) {
3315        case '-':
3316                if (!prefixcmp(arg, "-width")) {
3317                        arg += strlen("-width");
3318                        if (*arg == '=')
3319                                width = strtoul(arg + 1, &end, 10);
3320                        else if (!*arg && !av[1])
3321                                die("Option '--stat-width' requires a value");
3322                        else if (!*arg) {
3323                                width = strtoul(av[1], &end, 10);
3324                                argcount = 2;
3325                        }
3326                } else if (!prefixcmp(arg, "-name-width")) {
3327                        arg += strlen("-name-width");
3328                        if (*arg == '=')
3329                                name_width = strtoul(arg + 1, &end, 10);
3330                        else if (!*arg && !av[1])
3331                                die("Option '--stat-name-width' requires a value");
3332                        else if (!*arg) {
3333                                name_width = strtoul(av[1], &end, 10);
3334                                argcount = 2;
3335                        }
3336                } else if (!prefixcmp(arg, "-graph-width")) {
3337                        arg += strlen("-graph-width");
3338                        if (*arg == '=')
3339                                graph_width = strtoul(arg + 1, &end, 10);
3340                        else if (!*arg && !av[1])
3341                                die("Option '--stat-graph-width' requires a value");
3342                        else if (!*arg) {
3343                                graph_width = strtoul(av[1], &end, 10);
3344                                argcount = 2;
3345                        }
3346                } else if (!prefixcmp(arg, "-count")) {
3347                        arg += strlen("-count");
3348                        if (*arg == '=')
3349                                count = strtoul(arg + 1, &end, 10);
3350                        else if (!*arg && !av[1])
3351                                die("Option '--stat-count' requires a value");
3352                        else if (!*arg) {
3353                                count = strtoul(av[1], &end, 10);
3354                                argcount = 2;
3355                        }
3356                }
3357                break;
3358        case '=':
3359                width = strtoul(arg+1, &end, 10);
3360                if (*end == ',')
3361                        name_width = strtoul(end+1, &end, 10);
3362                if (*end == ',')
3363                        count = strtoul(end+1, &end, 10);
3364        }
3365
3366        /* Important! This checks all the error cases! */
3367        if (*end)
3368                return 0;
3369        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3370        options->stat_name_width = name_width;
3371        options->stat_graph_width = graph_width;
3372        options->stat_width = width;
3373        options->stat_count = count;
3374        return argcount;
3375}
3376
3377static int parse_dirstat_opt(struct diff_options *options, const char *params)
3378{
3379        struct strbuf errmsg = STRBUF_INIT;
3380        if (parse_dirstat_params(options, params, &errmsg))
3381                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3382                    errmsg.buf);
3383        strbuf_release(&errmsg);
3384        /*
3385         * The caller knows a dirstat-related option is given from the command
3386         * line; allow it to say "return this_function();"
3387         */
3388        options->output_format |= DIFF_FORMAT_DIRSTAT;
3389        return 1;
3390}
3391
3392int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3393{
3394        const char *arg = av[0];
3395        const char *optarg;
3396        int argcount;
3397
3398        /* Output format options */
3399        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3400                options->output_format |= DIFF_FORMAT_PATCH;
3401        else if (opt_arg(arg, 'U', "unified", &options->context))
3402                options->output_format |= DIFF_FORMAT_PATCH;
3403        else if (!strcmp(arg, "--raw"))
3404                options->output_format |= DIFF_FORMAT_RAW;
3405        else if (!strcmp(arg, "--patch-with-raw"))
3406                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3407        else if (!strcmp(arg, "--numstat"))
3408                options->output_format |= DIFF_FORMAT_NUMSTAT;
3409        else if (!strcmp(arg, "--shortstat"))
3410                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3411        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3412                return parse_dirstat_opt(options, "");
3413        else if (!prefixcmp(arg, "-X"))
3414                return parse_dirstat_opt(options, arg + 2);
3415        else if (!prefixcmp(arg, "--dirstat="))
3416                return parse_dirstat_opt(options, arg + 10);
3417        else if (!strcmp(arg, "--cumulative"))
3418                return parse_dirstat_opt(options, "cumulative");
3419        else if (!strcmp(arg, "--dirstat-by-file"))
3420                return parse_dirstat_opt(options, "files");
3421        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3422                parse_dirstat_opt(options, "files");
3423                return parse_dirstat_opt(options, arg + 18);
3424        }
3425        else if (!strcmp(arg, "--check"))
3426                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3427        else if (!strcmp(arg, "--summary"))
3428                options->output_format |= DIFF_FORMAT_SUMMARY;
3429        else if (!strcmp(arg, "--patch-with-stat"))
3430                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3431        else if (!strcmp(arg, "--name-only"))
3432                options->output_format |= DIFF_FORMAT_NAME;
3433        else if (!strcmp(arg, "--name-status"))
3434                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3435        else if (!strcmp(arg, "-s"))
3436                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3437        else if (!prefixcmp(arg, "--stat"))
3438                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3439                return stat_opt(options, av);
3440
3441        /* renames options */
3442        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3443                 !strcmp(arg, "--break-rewrites")) {
3444                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3445                        return error("invalid argument to -B: %s", arg+2);
3446        }
3447        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3448                 !strcmp(arg, "--find-renames")) {
3449                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3450                        return error("invalid argument to -M: %s", arg+2);
3451                options->detect_rename = DIFF_DETECT_RENAME;
3452        }
3453        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3454                options->irreversible_delete = 1;
3455        }
3456        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3457                 !strcmp(arg, "--find-copies")) {
3458                if (options->detect_rename == DIFF_DETECT_COPY)
3459                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3460                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3461                        return error("invalid argument to -C: %s", arg+2);
3462                options->detect_rename = DIFF_DETECT_COPY;
3463        }
3464        else if (!strcmp(arg, "--no-renames"))
3465                options->detect_rename = 0;
3466        else if (!strcmp(arg, "--relative"))
3467                DIFF_OPT_SET(options, RELATIVE_NAME);
3468        else if (!prefixcmp(arg, "--relative=")) {
3469                DIFF_OPT_SET(options, RELATIVE_NAME);
3470                options->prefix = arg + 11;
3471        }
3472
3473        /* xdiff options */
3474        else if (!strcmp(arg, "--minimal"))
3475                DIFF_XDL_SET(options, NEED_MINIMAL);
3476        else if (!strcmp(arg, "--no-minimal"))
3477                DIFF_XDL_CLR(options, NEED_MINIMAL);
3478        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3479                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3480        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3481                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3482        else if (!strcmp(arg, "--ignore-space-at-eol"))
3483                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3484        else if (!strcmp(arg, "--patience"))
3485                DIFF_XDL_SET(options, PATIENCE_DIFF);
3486        else if (!strcmp(arg, "--histogram"))
3487                DIFF_XDL_SET(options, HISTOGRAM_DIFF);
3488
3489        /* flags options */
3490        else if (!strcmp(arg, "--binary")) {
3491                options->output_format |= DIFF_FORMAT_PATCH;
3492                DIFF_OPT_SET(options, BINARY);
3493        }
3494        else if (!strcmp(arg, "--full-index"))
3495                DIFF_OPT_SET(options, FULL_INDEX);
3496        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3497                DIFF_OPT_SET(options, TEXT);
3498        else if (!strcmp(arg, "-R"))
3499                DIFF_OPT_SET(options, REVERSE_DIFF);
3500        else if (!strcmp(arg, "--find-copies-harder"))
3501                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3502        else if (!strcmp(arg, "--follow"))
3503                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3504        else if (!strcmp(arg, "--color"))
3505                options->use_color = 1;
3506        else if (!prefixcmp(arg, "--color=")) {
3507                int value = git_config_colorbool(NULL, arg+8);
3508                if (value < 0)
3509                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3510                options->use_color = value;
3511        }
3512        else if (!strcmp(arg, "--no-color"))
3513                options->use_color = 0;
3514        else if (!strcmp(arg, "--color-words")) {
3515                options->use_color = 1;
3516                options->word_diff = DIFF_WORDS_COLOR;
3517        }
3518        else if (!prefixcmp(arg, "--color-words=")) {
3519                options->use_color = 1;
3520                options->word_diff = DIFF_WORDS_COLOR;
3521                options->word_regex = arg + 14;
3522        }
3523        else if (!strcmp(arg, "--word-diff")) {
3524                if (options->word_diff == DIFF_WORDS_NONE)
3525                        options->word_diff = DIFF_WORDS_PLAIN;
3526        }
3527        else if (!prefixcmp(arg, "--word-diff=")) {
3528                const char *type = arg + 12;
3529                if (!strcmp(type, "plain"))
3530                        options->word_diff = DIFF_WORDS_PLAIN;
3531                else if (!strcmp(type, "color")) {
3532                        options->use_color = 1;
3533                        options->word_diff = DIFF_WORDS_COLOR;
3534                }
3535                else if (!strcmp(type, "porcelain"))
3536                        options->word_diff = DIFF_WORDS_PORCELAIN;
3537                else if (!strcmp(type, "none"))
3538                        options->word_diff = DIFF_WORDS_NONE;
3539                else
3540                        die("bad --word-diff argument: %s", type);
3541        }
3542        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3543                if (options->word_diff == DIFF_WORDS_NONE)
3544                        options->word_diff = DIFF_WORDS_PLAIN;
3545                options->word_regex = optarg;
3546                return argcount;
3547        }
3548        else if (!strcmp(arg, "--exit-code"))
3549                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3550        else if (!strcmp(arg, "--quiet"))
3551                DIFF_OPT_SET(options, QUICK);
3552        else if (!strcmp(arg, "--ext-diff"))
3553                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3554        else if (!strcmp(arg, "--no-ext-diff"))
3555                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3556        else if (!strcmp(arg, "--textconv"))
3557                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3558        else if (!strcmp(arg, "--no-textconv"))
3559                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3560        else if (!strcmp(arg, "--ignore-submodules")) {
3561                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3562                handle_ignore_submodules_arg(options, "all");
3563        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3564                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3565                handle_ignore_submodules_arg(options, arg + 20);
3566        } else if (!strcmp(arg, "--submodule"))
3567                DIFF_OPT_SET(options, SUBMODULE_LOG);
3568        else if (!prefixcmp(arg, "--submodule=")) {
3569                if (!strcmp(arg + 12, "log"))
3570                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3571        }
3572
3573        /* misc options */
3574        else if (!strcmp(arg, "-z"))
3575                options->line_termination = 0;
3576        else if ((argcount = short_opt('l', av, &optarg))) {
3577                options->rename_limit = strtoul(optarg, NULL, 10);
3578                return argcount;
3579        }
3580        else if ((argcount = short_opt('S', av, &optarg))) {
3581                options->pickaxe = optarg;
3582                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3583                return argcount;
3584        } else if ((argcount = short_opt('G', av, &optarg))) {
3585                options->pickaxe = optarg;
3586                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3587                return argcount;
3588        }
3589        else if (!strcmp(arg, "--pickaxe-all"))
3590                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3591        else if (!strcmp(arg, "--pickaxe-regex"))
3592                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3593        else if ((argcount = short_opt('O', av, &optarg))) {
3594                options->orderfile = optarg;
3595                return argcount;
3596        }
3597        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3598                options->filter = optarg;
3599                return argcount;
3600        }
3601        else if (!strcmp(arg, "--abbrev"))
3602                options->abbrev = DEFAULT_ABBREV;
3603        else if (!prefixcmp(arg, "--abbrev=")) {
3604                options->abbrev = strtoul(arg + 9, NULL, 10);
3605                if (options->abbrev < MINIMUM_ABBREV)
3606                        options->abbrev = MINIMUM_ABBREV;
3607                else if (40 < options->abbrev)
3608                        options->abbrev = 40;
3609        }
3610        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3611                options->a_prefix = optarg;
3612                return argcount;
3613        }
3614        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3615                options->b_prefix = optarg;
3616                return argcount;
3617        }
3618        else if (!strcmp(arg, "--no-prefix"))
3619                options->a_prefix = options->b_prefix = "";
3620        else if (opt_arg(arg, '\0', "inter-hunk-context",
3621                         &options->interhunkcontext))
3622                ;
3623        else if (!strcmp(arg, "-W"))
3624                DIFF_OPT_SET(options, FUNCCONTEXT);
3625        else if (!strcmp(arg, "--function-context"))
3626                DIFF_OPT_SET(options, FUNCCONTEXT);
3627        else if (!strcmp(arg, "--no-function-context"))
3628                DIFF_OPT_CLR(options, FUNCCONTEXT);
3629        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3630                options->file = fopen(optarg, "w");
3631                if (!options->file)
3632                        die_errno("Could not open '%s'", optarg);
3633                options->close_file = 1;
3634                return argcount;
3635        } else
3636                return 0;
3637        return 1;
3638}
3639
3640int parse_rename_score(const char **cp_p)
3641{
3642        unsigned long num, scale;
3643        int ch, dot;
3644        const char *cp = *cp_p;
3645
3646        num = 0;
3647        scale = 1;
3648        dot = 0;
3649        for (;;) {
3650                ch = *cp;
3651                if ( !dot && ch == '.' ) {
3652                        scale = 1;
3653                        dot = 1;
3654                } else if ( ch == '%' ) {
3655                        scale = dot ? scale*100 : 100;
3656                        cp++;   /* % is always at the end */
3657                        break;
3658                } else if ( ch >= '0' && ch <= '9' ) {
3659                        if ( scale < 100000 ) {
3660                                scale *= 10;
3661                                num = (num*10) + (ch-'0');
3662                        }
3663                } else {
3664                        break;
3665                }
3666                cp++;
3667        }
3668        *cp_p = cp;
3669
3670        /* user says num divided by scale and we say internally that
3671         * is MAX_SCORE * num / scale.
3672         */
3673        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3674}
3675
3676static int diff_scoreopt_parse(const char *opt)
3677{
3678        int opt1, opt2, cmd;
3679
3680        if (*opt++ != '-')
3681                return -1;
3682        cmd = *opt++;
3683        if (cmd == '-') {
3684                /* convert the long-form arguments into short-form versions */
3685                if (!prefixcmp(opt, "break-rewrites")) {
3686                        opt += strlen("break-rewrites");
3687                        if (*opt == 0 || *opt++ == '=')
3688                                cmd = 'B';
3689                } else if (!prefixcmp(opt, "find-copies")) {
3690                        opt += strlen("find-copies");
3691                        if (*opt == 0 || *opt++ == '=')
3692                                cmd = 'C';
3693                } else if (!prefixcmp(opt, "find-renames")) {
3694                        opt += strlen("find-renames");
3695                        if (*opt == 0 || *opt++ == '=')
3696                                cmd = 'M';
3697                }
3698        }
3699        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3700                return -1; /* that is not a -M, -C nor -B option */
3701
3702        opt1 = parse_rename_score(&opt);
3703        if (cmd != 'B')
3704                opt2 = 0;
3705        else {
3706                if (*opt == 0)
3707                        opt2 = 0;
3708                else if (*opt != '/')
3709                        return -1; /* we expect -B80/99 or -B80 */
3710                else {
3711                        opt++;
3712                        opt2 = parse_rename_score(&opt);
3713                }
3714        }
3715        if (*opt != 0)
3716                return -1;
3717        return opt1 | (opt2 << 16);
3718}
3719
3720struct diff_queue_struct diff_queued_diff;
3721
3722void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3723{
3724        if (queue->alloc <= queue->nr) {
3725                queue->alloc = alloc_nr(queue->alloc);
3726                queue->queue = xrealloc(queue->queue,
3727                                        sizeof(dp) * queue->alloc);
3728        }
3729        queue->queue[queue->nr++] = dp;
3730}
3731
3732struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3733                                 struct diff_filespec *one,
3734                                 struct diff_filespec *two)
3735{
3736        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3737        dp->one = one;
3738        dp->two = two;
3739        if (queue)
3740                diff_q(queue, dp);
3741        return dp;
3742}
3743
3744void diff_free_filepair(struct diff_filepair *p)
3745{
3746        free_filespec(p->one);
3747        free_filespec(p->two);
3748        free(p);
3749}
3750
3751/* This is different from find_unique_abbrev() in that
3752 * it stuffs the result with dots for alignment.
3753 */
3754const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3755{
3756        int abblen;
3757        const char *abbrev;
3758        if (len == 40)
3759                return sha1_to_hex(sha1);
3760
3761        abbrev = find_unique_abbrev(sha1, len);
3762        abblen = strlen(abbrev);
3763        if (abblen < 37) {
3764                static char hex[41];
3765                if (len < abblen && abblen <= len + 2)
3766                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3767                else
3768                        sprintf(hex, "%s...", abbrev);
3769                return hex;
3770        }
3771        return sha1_to_hex(sha1);
3772}
3773
3774static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3775{
3776        int line_termination = opt->line_termination;
3777        int inter_name_termination = line_termination ? '\t' : '\0';
3778        if (opt->output_prefix) {
3779                struct strbuf *msg = NULL;
3780                msg = opt->output_prefix(opt, opt->output_prefix_data);
3781                fprintf(opt->file, "%s", msg->buf);
3782        }
3783
3784        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3785                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3786                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3787                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3788        }
3789        if (p->score) {
3790                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3791                        inter_name_termination);
3792        } else {
3793                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3794        }
3795
3796        if (p->status == DIFF_STATUS_COPIED ||
3797            p->status == DIFF_STATUS_RENAMED) {
3798                const char *name_a, *name_b;
3799                name_a = p->one->path;
3800                name_b = p->two->path;
3801                strip_prefix(opt->prefix_length, &name_a, &name_b);
3802                write_name_quoted(name_a, opt->file, inter_name_termination);
3803                write_name_quoted(name_b, opt->file, line_termination);
3804        } else {
3805                const char *name_a, *name_b;
3806                name_a = p->one->mode ? p->one->path : p->two->path;
3807                name_b = NULL;
3808                strip_prefix(opt->prefix_length, &name_a, &name_b);
3809                write_name_quoted(name_a, opt->file, line_termination);
3810        }
3811}
3812
3813int diff_unmodified_pair(struct diff_filepair *p)
3814{
3815        /* This function is written stricter than necessary to support
3816         * the currently implemented transformers, but the idea is to
3817         * let transformers to produce diff_filepairs any way they want,
3818         * and filter and clean them up here before producing the output.
3819         */
3820        struct diff_filespec *one = p->one, *two = p->two;
3821
3822        if (DIFF_PAIR_UNMERGED(p))
3823                return 0; /* unmerged is interesting */
3824
3825        /* deletion, addition, mode or type change
3826         * and rename are all interesting.
3827         */
3828        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3829            DIFF_PAIR_MODE_CHANGED(p) ||
3830            strcmp(one->path, two->path))
3831                return 0;
3832
3833        /* both are valid and point at the same path.  that is, we are
3834         * dealing with a change.
3835         */
3836        if (one->sha1_valid && two->sha1_valid &&
3837            !hashcmp(one->sha1, two->sha1) &&
3838            !one->dirty_submodule && !two->dirty_submodule)
3839                return 1; /* no change */
3840        if (!one->sha1_valid && !two->sha1_valid)
3841                return 1; /* both look at the same file on the filesystem. */
3842        return 0;
3843}
3844
3845static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3846{
3847        if (diff_unmodified_pair(p))
3848                return;
3849
3850        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3851            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3852                return; /* no tree diffs in patch format */
3853
3854        run_diff(p, o);
3855}
3856
3857static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3858                            struct diffstat_t *diffstat)
3859{
3860        if (diff_unmodified_pair(p))
3861                return;
3862
3863        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3864            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3865                return; /* no useful stat for tree diffs */
3866
3867        run_diffstat(p, o, diffstat);
3868}
3869
3870static void diff_flush_checkdiff(struct diff_filepair *p,
3871                struct diff_options *o)
3872{
3873        if (diff_unmodified_pair(p))
3874                return;
3875
3876        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3877            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3878                return; /* nothing to check in tree diffs */
3879
3880        run_checkdiff(p, o);
3881}
3882
3883int diff_queue_is_empty(void)
3884{
3885        struct diff_queue_struct *q = &diff_queued_diff;
3886        int i;
3887        for (i = 0; i < q->nr; i++)
3888                if (!diff_unmodified_pair(q->queue[i]))
3889                        return 0;
3890        return 1;
3891}
3892
3893#if DIFF_DEBUG
3894void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3895{
3896        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3897                x, one ? one : "",
3898                s->path,
3899                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3900                s->mode,
3901                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3902        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3903                x, one ? one : "",
3904                s->size, s->xfrm_flags);
3905}
3906
3907void diff_debug_filepair(const struct diff_filepair *p, int i)
3908{
3909        diff_debug_filespec(p->one, i, "one");
3910        diff_debug_filespec(p->two, i, "two");
3911        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3912                p->score, p->status ? p->status : '?',
3913                p->one->rename_used, p->broken_pair);
3914}
3915
3916void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3917{
3918        int i;
3919        if (msg)
3920                fprintf(stderr, "%s\n", msg);
3921        fprintf(stderr, "q->nr = %d\n", q->nr);
3922        for (i = 0; i < q->nr; i++) {
3923                struct diff_filepair *p = q->queue[i];
3924                diff_debug_filepair(p, i);
3925        }
3926}
3927#endif
3928
3929static void diff_resolve_rename_copy(void)
3930{
3931        int i;
3932        struct diff_filepair *p;
3933        struct diff_queue_struct *q = &diff_queued_diff;
3934
3935        diff_debug_queue("resolve-rename-copy", q);
3936
3937        for (i = 0; i < q->nr; i++) {
3938                p = q->queue[i];
3939                p->status = 0; /* undecided */
3940                if (DIFF_PAIR_UNMERGED(p))
3941                        p->status = DIFF_STATUS_UNMERGED;
3942                else if (!DIFF_FILE_VALID(p->one))
3943                        p->status = DIFF_STATUS_ADDED;
3944                else if (!DIFF_FILE_VALID(p->two))
3945                        p->status = DIFF_STATUS_DELETED;
3946                else if (DIFF_PAIR_TYPE_CHANGED(p))
3947                        p->status = DIFF_STATUS_TYPE_CHANGED;
3948
3949                /* from this point on, we are dealing with a pair
3950                 * whose both sides are valid and of the same type, i.e.
3951                 * either in-place edit or rename/copy edit.
3952                 */
3953                else if (DIFF_PAIR_RENAME(p)) {
3954                        /*
3955                         * A rename might have re-connected a broken
3956                         * pair up, causing the pathnames to be the
3957                         * same again. If so, that's not a rename at
3958                         * all, just a modification..
3959                         *
3960                         * Otherwise, see if this source was used for
3961                         * multiple renames, in which case we decrement
3962                         * the count, and call it a copy.
3963                         */
3964                        if (!strcmp(p->one->path, p->two->path))
3965                                p->status = DIFF_STATUS_MODIFIED;
3966                        else if (--p->one->rename_used > 0)
3967                                p->status = DIFF_STATUS_COPIED;
3968                        else
3969                                p->status = DIFF_STATUS_RENAMED;
3970                }
3971                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3972                         p->one->mode != p->two->mode ||
3973                         p->one->dirty_submodule ||
3974                         p->two->dirty_submodule ||
3975                         is_null_sha1(p->one->sha1))
3976                        p->status = DIFF_STATUS_MODIFIED;
3977                else {
3978                        /* This is a "no-change" entry and should not
3979                         * happen anymore, but prepare for broken callers.
3980                         */
3981                        error("feeding unmodified %s to diffcore",
3982                              p->one->path);
3983                        p->status = DIFF_STATUS_UNKNOWN;
3984                }
3985        }
3986        diff_debug_queue("resolve-rename-copy done", q);
3987}
3988
3989static int check_pair_status(struct diff_filepair *p)
3990{
3991        switch (p->status) {
3992        case DIFF_STATUS_UNKNOWN:
3993                return 0;
3994        case 0:
3995                die("internal error in diff-resolve-rename-copy");
3996        default:
3997                return 1;
3998        }
3999}
4000
4001static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4002{
4003        int fmt = opt->output_format;
4004
4005        if (fmt & DIFF_FORMAT_CHECKDIFF)
4006                diff_flush_checkdiff(p, opt);
4007        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4008                diff_flush_raw(p, opt);
4009        else if (fmt & DIFF_FORMAT_NAME) {
4010                const char *name_a, *name_b;
4011                name_a = p->two->path;
4012                name_b = NULL;
4013                strip_prefix(opt->prefix_length, &name_a, &name_b);
4014                write_name_quoted(name_a, opt->file, opt->line_termination);
4015        }
4016}
4017
4018static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4019{
4020        if (fs->mode)
4021                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4022        else
4023                fprintf(file, " %s ", newdelete);
4024        write_name_quoted(fs->path, file, '\n');
4025}
4026
4027
4028static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4029                const char *line_prefix)
4030{
4031        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4032                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4033                        p->two->mode, show_name ? ' ' : '\n');
4034                if (show_name) {
4035                        write_name_quoted(p->two->path, file, '\n');
4036                }
4037        }
4038}
4039
4040static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4041                        const char *line_prefix)
4042{
4043        char *names = pprint_rename(p->one->path, p->two->path);
4044
4045        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4046        free(names);
4047        show_mode_change(file, p, 0, line_prefix);
4048}
4049
4050static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4051{
4052        FILE *file = opt->file;
4053        char *line_prefix = "";
4054
4055        if (opt->output_prefix) {
4056                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4057                line_prefix = buf->buf;
4058        }
4059
4060        switch(p->status) {
4061        case DIFF_STATUS_DELETED:
4062                fputs(line_prefix, file);
4063                show_file_mode_name(file, "delete", p->one);
4064                break;
4065        case DIFF_STATUS_ADDED:
4066                fputs(line_prefix, file);
4067                show_file_mode_name(file, "create", p->two);
4068                break;
4069        case DIFF_STATUS_COPIED:
4070                fputs(line_prefix, file);
4071                show_rename_copy(file, "copy", p, line_prefix);
4072                break;
4073        case DIFF_STATUS_RENAMED:
4074                fputs(line_prefix, file);
4075                show_rename_copy(file, "rename", p, line_prefix);
4076                break;
4077        default:
4078                if (p->score) {
4079                        fprintf(file, "%s rewrite ", line_prefix);
4080                        write_name_quoted(p->two->path, file, ' ');
4081                        fprintf(file, "(%d%%)\n", similarity_index(p));
4082                }
4083                show_mode_change(file, p, !p->score, line_prefix);
4084                break;
4085        }
4086}
4087
4088struct patch_id_t {
4089        git_SHA_CTX *ctx;
4090        int patchlen;
4091};
4092
4093static int remove_space(char *line, int len)
4094{
4095        int i;
4096        char *dst = line;
4097        unsigned char c;
4098
4099        for (i = 0; i < len; i++)
4100                if (!isspace((c = line[i])))
4101                        *dst++ = c;
4102
4103        return dst - line;
4104}
4105
4106static void patch_id_consume(void *priv, char *line, unsigned long len)
4107{
4108        struct patch_id_t *data = priv;
4109        int new_len;
4110
4111        /* Ignore line numbers when computing the SHA1 of the patch */
4112        if (!prefixcmp(line, "@@ -"))
4113                return;
4114
4115        new_len = remove_space(line, len);
4116
4117        git_SHA1_Update(data->ctx, line, new_len);
4118        data->patchlen += new_len;
4119}
4120
4121/* returns 0 upon success, and writes result into sha1 */
4122static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4123{
4124        struct diff_queue_struct *q = &diff_queued_diff;
4125        int i;
4126        git_SHA_CTX ctx;
4127        struct patch_id_t data;
4128        char buffer[PATH_MAX * 4 + 20];
4129
4130        git_SHA1_Init(&ctx);
4131        memset(&data, 0, sizeof(struct patch_id_t));
4132        data.ctx = &ctx;
4133
4134        for (i = 0; i < q->nr; i++) {
4135                xpparam_t xpp;
4136                xdemitconf_t xecfg;
4137                mmfile_t mf1, mf2;
4138                struct diff_filepair *p = q->queue[i];
4139                int len1, len2;
4140
4141                memset(&xpp, 0, sizeof(xpp));
4142                memset(&xecfg, 0, sizeof(xecfg));
4143                if (p->status == 0)
4144                        return error("internal diff status error");
4145                if (p->status == DIFF_STATUS_UNKNOWN)
4146                        continue;
4147                if (diff_unmodified_pair(p))
4148                        continue;
4149                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4150                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4151                        continue;
4152                if (DIFF_PAIR_UNMERGED(p))
4153                        continue;
4154
4155                diff_fill_sha1_info(p->one);
4156                diff_fill_sha1_info(p->two);
4157                if (fill_mmfile(&mf1, p->one) < 0 ||
4158                                fill_mmfile(&mf2, p->two) < 0)
4159                        return error("unable to read files to diff");
4160
4161                len1 = remove_space(p->one->path, strlen(p->one->path));
4162                len2 = remove_space(p->two->path, strlen(p->two->path));
4163                if (p->one->mode == 0)
4164                        len1 = snprintf(buffer, sizeof(buffer),
4165                                        "diff--gita/%.*sb/%.*s"
4166                                        "newfilemode%06o"
4167                                        "---/dev/null"
4168                                        "+++b/%.*s",
4169                                        len1, p->one->path,
4170                                        len2, p->two->path,
4171                                        p->two->mode,
4172                                        len2, p->two->path);
4173                else if (p->two->mode == 0)
4174                        len1 = snprintf(buffer, sizeof(buffer),
4175                                        "diff--gita/%.*sb/%.*s"
4176                                        "deletedfilemode%06o"
4177                                        "---a/%.*s"
4178                                        "+++/dev/null",
4179                                        len1, p->one->path,
4180                                        len2, p->two->path,
4181                                        p->one->mode,
4182                                        len1, p->one->path);
4183                else
4184                        len1 = snprintf(buffer, sizeof(buffer),
4185                                        "diff--gita/%.*sb/%.*s"
4186                                        "---a/%.*s"
4187                                        "+++b/%.*s",
4188                                        len1, p->one->path,
4189                                        len2, p->two->path,
4190                                        len1, p->one->path,
4191                                        len2, p->two->path);
4192                git_SHA1_Update(&ctx, buffer, len1);
4193
4194                if (diff_filespec_is_binary(p->one) ||
4195                    diff_filespec_is_binary(p->two)) {
4196                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4197                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4198                        continue;
4199                }
4200
4201                xpp.flags = 0;
4202                xecfg.ctxlen = 3;
4203                xecfg.flags = 0;
4204                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4205                              &xpp, &xecfg);
4206        }
4207
4208        git_SHA1_Final(sha1, &ctx);
4209        return 0;
4210}
4211
4212int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4213{
4214        struct diff_queue_struct *q = &diff_queued_diff;
4215        int i;
4216        int result = diff_get_patch_id(options, sha1);
4217
4218        for (i = 0; i < q->nr; i++)
4219                diff_free_filepair(q->queue[i]);
4220
4221        free(q->queue);
4222        DIFF_QUEUE_CLEAR(q);
4223
4224        return result;
4225}
4226
4227static int is_summary_empty(const struct diff_queue_struct *q)
4228{
4229        int i;
4230
4231        for (i = 0; i < q->nr; i++) {
4232                const struct diff_filepair *p = q->queue[i];
4233
4234                switch (p->status) {
4235                case DIFF_STATUS_DELETED:
4236                case DIFF_STATUS_ADDED:
4237                case DIFF_STATUS_COPIED:
4238                case DIFF_STATUS_RENAMED:
4239                        return 0;
4240                default:
4241                        if (p->score)
4242                                return 0;
4243                        if (p->one->mode && p->two->mode &&
4244                            p->one->mode != p->two->mode)
4245                                return 0;
4246                        break;
4247                }
4248        }
4249        return 1;
4250}
4251
4252static const char rename_limit_warning[] =
4253"inexact rename detection was skipped due to too many files.";
4254
4255static const char degrade_cc_to_c_warning[] =
4256"only found copies from modified paths due to too many files.";
4257
4258static const char rename_limit_advice[] =
4259"you may want to set your %s variable to at least "
4260"%d and retry the command.";
4261
4262void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4263{
4264        if (degraded_cc)
4265                warning(degrade_cc_to_c_warning);
4266        else if (needed)
4267                warning(rename_limit_warning);
4268        else
4269                return;
4270        if (0 < needed && needed < 32767)
4271                warning(rename_limit_advice, varname, needed);
4272}
4273
4274void diff_flush(struct diff_options *options)
4275{
4276        struct diff_queue_struct *q = &diff_queued_diff;
4277        int i, output_format = options->output_format;
4278        int separator = 0;
4279        int dirstat_by_line = 0;
4280
4281        /*
4282         * Order: raw, stat, summary, patch
4283         * or:    name/name-status/checkdiff (other bits clear)
4284         */
4285        if (!q->nr)
4286                goto free_queue;
4287
4288        if (output_format & (DIFF_FORMAT_RAW |
4289                             DIFF_FORMAT_NAME |
4290                             DIFF_FORMAT_NAME_STATUS |
4291                             DIFF_FORMAT_CHECKDIFF)) {
4292                for (i = 0; i < q->nr; i++) {
4293                        struct diff_filepair *p = q->queue[i];
4294                        if (check_pair_status(p))
4295                                flush_one_pair(p, options);
4296                }
4297                separator++;
4298        }
4299
4300        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4301                dirstat_by_line = 1;
4302
4303        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4304            dirstat_by_line) {
4305                struct diffstat_t diffstat;
4306
4307                memset(&diffstat, 0, sizeof(struct diffstat_t));
4308                for (i = 0; i < q->nr; i++) {
4309                        struct diff_filepair *p = q->queue[i];
4310                        if (check_pair_status(p))
4311                                diff_flush_stat(p, options, &diffstat);
4312                }
4313                if (output_format & DIFF_FORMAT_NUMSTAT)
4314                        show_numstat(&diffstat, options);
4315                if (output_format & DIFF_FORMAT_DIFFSTAT)
4316                        show_stats(&diffstat, options);
4317                if (output_format & DIFF_FORMAT_SHORTSTAT)
4318                        show_shortstats(&diffstat, options);
4319                if (output_format & DIFF_FORMAT_DIRSTAT)
4320                        show_dirstat_by_line(&diffstat, options);
4321                free_diffstat_info(&diffstat);
4322                separator++;
4323        }
4324        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4325                show_dirstat(options);
4326
4327        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4328                for (i = 0; i < q->nr; i++) {
4329                        diff_summary(options, q->queue[i]);
4330                }
4331                separator++;
4332        }
4333
4334        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4335            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4336            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4337                /*
4338                 * run diff_flush_patch for the exit status. setting
4339                 * options->file to /dev/null should be safe, becaue we
4340                 * aren't supposed to produce any output anyway.
4341                 */
4342                if (options->close_file)
4343                        fclose(options->file);
4344                options->file = fopen("/dev/null", "w");
4345                if (!options->file)
4346                        die_errno("Could not open /dev/null");
4347                options->close_file = 1;
4348                for (i = 0; i < q->nr; i++) {
4349                        struct diff_filepair *p = q->queue[i];
4350                        if (check_pair_status(p))
4351                                diff_flush_patch(p, options);
4352                        if (options->found_changes)
4353                                break;
4354                }
4355        }
4356
4357        if (output_format & DIFF_FORMAT_PATCH) {
4358                if (separator) {
4359                        putc(options->line_termination, options->file);
4360                        if (options->stat_sep) {
4361                                /* attach patch instead of inline */
4362                                fputs(options->stat_sep, options->file);
4363                        }
4364                }
4365
4366                for (i = 0; i < q->nr; i++) {
4367                        struct diff_filepair *p = q->queue[i];
4368                        if (check_pair_status(p))
4369                                diff_flush_patch(p, options);
4370                }
4371        }
4372
4373        if (output_format & DIFF_FORMAT_CALLBACK)
4374                options->format_callback(q, options, options->format_callback_data);
4375
4376        for (i = 0; i < q->nr; i++)
4377                diff_free_filepair(q->queue[i]);
4378free_queue:
4379        free(q->queue);
4380        DIFF_QUEUE_CLEAR(q);
4381        if (options->close_file)
4382                fclose(options->file);
4383
4384        /*
4385         * Report the content-level differences with HAS_CHANGES;
4386         * diff_addremove/diff_change does not set the bit when
4387         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4388         */
4389        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4390                if (options->found_changes)
4391                        DIFF_OPT_SET(options, HAS_CHANGES);
4392                else
4393                        DIFF_OPT_CLR(options, HAS_CHANGES);
4394        }
4395}
4396
4397static void diffcore_apply_filter(const char *filter)
4398{
4399        int i;
4400        struct diff_queue_struct *q = &diff_queued_diff;
4401        struct diff_queue_struct outq;
4402        DIFF_QUEUE_CLEAR(&outq);
4403
4404        if (!filter)
4405                return;
4406
4407        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4408                int found;
4409                for (i = found = 0; !found && i < q->nr; i++) {
4410                        struct diff_filepair *p = q->queue[i];
4411                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4412                             ((p->score &&
4413                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4414                              (!p->score &&
4415                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4416                            ((p->status != DIFF_STATUS_MODIFIED) &&
4417                             strchr(filter, p->status)))
4418                                found++;
4419                }
4420                if (found)
4421                        return;
4422
4423                /* otherwise we will clear the whole queue
4424                 * by copying the empty outq at the end of this
4425                 * function, but first clear the current entries
4426                 * in the queue.
4427                 */
4428                for (i = 0; i < q->nr; i++)
4429                        diff_free_filepair(q->queue[i]);
4430        }
4431        else {
4432                /* Only the matching ones */
4433                for (i = 0; i < q->nr; i++) {
4434                        struct diff_filepair *p = q->queue[i];
4435
4436                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4437                             ((p->score &&
4438                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4439                              (!p->score &&
4440                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4441                            ((p->status != DIFF_STATUS_MODIFIED) &&
4442                             strchr(filter, p->status)))
4443                                diff_q(&outq, p);
4444                        else
4445                                diff_free_filepair(p);
4446                }
4447        }
4448        free(q->queue);
4449        *q = outq;
4450}
4451
4452/* Check whether two filespecs with the same mode and size are identical */
4453static int diff_filespec_is_identical(struct diff_filespec *one,
4454                                      struct diff_filespec *two)
4455{
4456        if (S_ISGITLINK(one->mode))
4457                return 0;
4458        if (diff_populate_filespec(one, 0))
4459                return 0;
4460        if (diff_populate_filespec(two, 0))
4461                return 0;
4462        return !memcmp(one->data, two->data, one->size);
4463}
4464
4465static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4466{
4467        int i;
4468        struct diff_queue_struct *q = &diff_queued_diff;
4469        struct diff_queue_struct outq;
4470        DIFF_QUEUE_CLEAR(&outq);
4471
4472        for (i = 0; i < q->nr; i++) {
4473                struct diff_filepair *p = q->queue[i];
4474
4475                /*
4476                 * 1. Entries that come from stat info dirtiness
4477                 *    always have both sides (iow, not create/delete),
4478                 *    one side of the object name is unknown, with
4479                 *    the same mode and size.  Keep the ones that
4480                 *    do not match these criteria.  They have real
4481                 *    differences.
4482                 *
4483                 * 2. At this point, the file is known to be modified,
4484                 *    with the same mode and size, and the object
4485                 *    name of one side is unknown.  Need to inspect
4486                 *    the identical contents.
4487                 */
4488                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4489                    !DIFF_FILE_VALID(p->two) ||
4490                    (p->one->sha1_valid && p->two->sha1_valid) ||
4491                    (p->one->mode != p->two->mode) ||
4492                    diff_populate_filespec(p->one, 1) ||
4493                    diff_populate_filespec(p->two, 1) ||
4494                    (p->one->size != p->two->size) ||
4495                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4496                        diff_q(&outq, p);
4497                else {
4498                        /*
4499                         * The caller can subtract 1 from skip_stat_unmatch
4500                         * to determine how many paths were dirty only
4501                         * due to stat info mismatch.
4502                         */
4503                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4504                                diffopt->skip_stat_unmatch++;
4505                        diff_free_filepair(p);
4506                }
4507        }
4508        free(q->queue);
4509        *q = outq;
4510}
4511
4512static int diffnamecmp(const void *a_, const void *b_)
4513{
4514        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4515        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4516        const char *name_a, *name_b;
4517
4518        name_a = a->one ? a->one->path : a->two->path;
4519        name_b = b->one ? b->one->path : b->two->path;
4520        return strcmp(name_a, name_b);
4521}
4522
4523void diffcore_fix_diff_index(struct diff_options *options)
4524{
4525        struct diff_queue_struct *q = &diff_queued_diff;
4526        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4527}
4528
4529void diffcore_std(struct diff_options *options)
4530{
4531        if (options->skip_stat_unmatch)
4532                diffcore_skip_stat_unmatch(options);
4533        if (!options->found_follow) {
4534                /* See try_to_follow_renames() in tree-diff.c */
4535                if (options->break_opt != -1)
4536                        diffcore_break(options->break_opt);
4537                if (options->detect_rename)
4538                        diffcore_rename(options);
4539                if (options->break_opt != -1)
4540                        diffcore_merge_broken();
4541        }
4542        if (options->pickaxe)
4543                diffcore_pickaxe(options);
4544        if (options->orderfile)
4545                diffcore_order(options->orderfile);
4546        if (!options->found_follow)
4547                /* See try_to_follow_renames() in tree-diff.c */
4548                diff_resolve_rename_copy();
4549        diffcore_apply_filter(options->filter);
4550
4551        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4552                DIFF_OPT_SET(options, HAS_CHANGES);
4553        else
4554                DIFF_OPT_CLR(options, HAS_CHANGES);
4555
4556        options->found_follow = 0;
4557}
4558
4559int diff_result_code(struct diff_options *opt, int status)
4560{
4561        int result = 0;
4562
4563        diff_warn_rename_limit("diff.renamelimit",
4564                               opt->needed_rename_limit,
4565                               opt->degraded_cc_to_c);
4566        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4567            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4568                return status;
4569        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4570            DIFF_OPT_TST(opt, HAS_CHANGES))
4571                result |= 01;
4572        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4573            DIFF_OPT_TST(opt, CHECK_FAILED))
4574                result |= 02;
4575        return result;
4576}
4577
4578int diff_can_quit_early(struct diff_options *opt)
4579{
4580        return (DIFF_OPT_TST(opt, QUICK) &&
4581                !opt->filter &&
4582                DIFF_OPT_TST(opt, HAS_CHANGES));
4583}
4584
4585/*
4586 * Shall changes to this submodule be ignored?
4587 *
4588 * Submodule changes can be configured to be ignored separately for each path,
4589 * but that configuration can be overridden from the command line.
4590 */
4591static int is_submodule_ignored(const char *path, struct diff_options *options)
4592{
4593        int ignored = 0;
4594        unsigned orig_flags = options->flags;
4595        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4596                set_diffopt_flags_from_submodule_config(options, path);
4597        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4598                ignored = 1;
4599        options->flags = orig_flags;
4600        return ignored;
4601}
4602
4603void diff_addremove(struct diff_options *options,
4604                    int addremove, unsigned mode,
4605                    const unsigned char *sha1,
4606                    const char *concatpath, unsigned dirty_submodule)
4607{
4608        struct diff_filespec *one, *two;
4609
4610        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4611                return;
4612
4613        /* This may look odd, but it is a preparation for
4614         * feeding "there are unchanged files which should
4615         * not produce diffs, but when you are doing copy
4616         * detection you would need them, so here they are"
4617         * entries to the diff-core.  They will be prefixed
4618         * with something like '=' or '*' (I haven't decided
4619         * which but should not make any difference).
4620         * Feeding the same new and old to diff_change()
4621         * also has the same effect.
4622         * Before the final output happens, they are pruned after
4623         * merged into rename/copy pairs as appropriate.
4624         */
4625        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4626                addremove = (addremove == '+' ? '-' :
4627                             addremove == '-' ? '+' : addremove);
4628
4629        if (options->prefix &&
4630            strncmp(concatpath, options->prefix, options->prefix_length))
4631                return;
4632
4633        one = alloc_filespec(concatpath);
4634        two = alloc_filespec(concatpath);
4635
4636        if (addremove != '+')
4637                fill_filespec(one, sha1, mode);
4638        if (addremove != '-') {
4639                fill_filespec(two, sha1, mode);
4640                two->dirty_submodule = dirty_submodule;
4641        }
4642
4643        diff_queue(&diff_queued_diff, one, two);
4644        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4645                DIFF_OPT_SET(options, HAS_CHANGES);
4646}
4647
4648void diff_change(struct diff_options *options,
4649                 unsigned old_mode, unsigned new_mode,
4650                 const unsigned char *old_sha1,
4651                 const unsigned char *new_sha1,
4652                 const char *concatpath,
4653                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4654{
4655        struct diff_filespec *one, *two;
4656
4657        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4658            is_submodule_ignored(concatpath, options))
4659                return;
4660
4661        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4662                unsigned tmp;
4663                const unsigned char *tmp_c;
4664                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4665                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4666                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4667                        new_dirty_submodule = tmp;
4668        }
4669
4670        if (options->prefix &&
4671            strncmp(concatpath, options->prefix, options->prefix_length))
4672                return;
4673
4674        one = alloc_filespec(concatpath);
4675        two = alloc_filespec(concatpath);
4676        fill_filespec(one, old_sha1, old_mode);
4677        fill_filespec(two, new_sha1, new_mode);
4678        one->dirty_submodule = old_dirty_submodule;
4679        two->dirty_submodule = new_dirty_submodule;
4680
4681        diff_queue(&diff_queued_diff, one, two);
4682        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4683                DIFF_OPT_SET(options, HAS_CHANGES);
4684}
4685
4686struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4687{
4688        struct diff_filepair *pair;
4689        struct diff_filespec *one, *two;
4690
4691        if (options->prefix &&
4692            strncmp(path, options->prefix, options->prefix_length))
4693                return NULL;
4694
4695        one = alloc_filespec(path);
4696        two = alloc_filespec(path);
4697        pair = diff_queue(&diff_queued_diff, one, two);
4698        pair->is_unmerged = 1;
4699        return pair;
4700}
4701
4702static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4703                size_t *outsize)
4704{
4705        struct diff_tempfile *temp;
4706        const char *argv[3];
4707        const char **arg = argv;
4708        struct child_process child;
4709        struct strbuf buf = STRBUF_INIT;
4710        int err = 0;
4711
4712        temp = prepare_temp_file(spec->path, spec);
4713        *arg++ = pgm;
4714        *arg++ = temp->name;
4715        *arg = NULL;
4716
4717        memset(&child, 0, sizeof(child));
4718        child.use_shell = 1;
4719        child.argv = argv;
4720        child.out = -1;
4721        if (start_command(&child)) {
4722                remove_tempfile();
4723                return NULL;
4724        }
4725
4726        if (strbuf_read(&buf, child.out, 0) < 0)
4727                err = error("error reading from textconv command '%s'", pgm);
4728        close(child.out);
4729
4730        if (finish_command(&child) || err) {
4731                strbuf_release(&buf);
4732                remove_tempfile();
4733                return NULL;
4734        }
4735        remove_tempfile();
4736
4737        return strbuf_detach(&buf, outsize);
4738}
4739
4740size_t fill_textconv(struct userdiff_driver *driver,
4741                     struct diff_filespec *df,
4742                     char **outbuf)
4743{
4744        size_t size;
4745
4746        if (!driver || !driver->textconv) {
4747                if (!DIFF_FILE_VALID(df)) {
4748                        *outbuf = "";
4749                        return 0;
4750                }
4751                if (diff_populate_filespec(df, 0))
4752                        die("unable to read files to diff");
4753                *outbuf = df->data;
4754                return df->size;
4755        }
4756
4757        if (driver->textconv_cache && df->sha1_valid) {
4758                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4759                                          &size);
4760                if (*outbuf)
4761                        return size;
4762        }
4763
4764        *outbuf = run_textconv(driver->textconv, df, &size);
4765        if (!*outbuf)
4766                die("unable to read files to diff");
4767
4768        if (driver->textconv_cache && df->sha1_valid) {
4769                /* ignore errors, as we might be in a readonly repository */
4770                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4771                                size);
4772                /*
4773                 * we could save up changes and flush them all at the end,
4774                 * but we would need an extra call after all diffing is done.
4775                 * Since generating a cache entry is the slow path anyway,
4776                 * this extra overhead probably isn't a big deal.
4777                 */
4778                notes_cache_write(driver->textconv_cache);
4779        }
4780
4781        return size;
4782}