diff.con commit Merge branch 'sz/maint-submodule-reference-arg' (1777144)
   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;
  28static int diff_use_color_default = -1;
  29static int diff_context_default = 3;
  30static const char *diff_word_regex_cfg;
  31static const char *external_diff_cmd_cfg;
  32int diff_auto_refresh_index = 1;
  33static int diff_mnemonic_prefix;
  34static int diff_no_prefix;
  35static int diff_stat_graph_width;
  36static int diff_dirstat_permille_default = 30;
  37static struct diff_options default_diff_options;
  38
  39static char diff_colors[][COLOR_MAXLEN] = {
  40        GIT_COLOR_RESET,
  41        GIT_COLOR_NORMAL,       /* PLAIN */
  42        GIT_COLOR_BOLD,         /* METAINFO */
  43        GIT_COLOR_CYAN,         /* FRAGINFO */
  44        GIT_COLOR_RED,          /* OLD */
  45        GIT_COLOR_GREEN,        /* NEW */
  46        GIT_COLOR_YELLOW,       /* COMMIT */
  47        GIT_COLOR_BG_RED,       /* WHITESPACE */
  48        GIT_COLOR_NORMAL,       /* FUNCINFO */
  49};
  50
  51static int parse_diff_color_slot(const char *var, int ofs)
  52{
  53        if (!strcasecmp(var+ofs, "plain"))
  54                return DIFF_PLAIN;
  55        if (!strcasecmp(var+ofs, "meta"))
  56                return DIFF_METAINFO;
  57        if (!strcasecmp(var+ofs, "frag"))
  58                return DIFF_FRAGINFO;
  59        if (!strcasecmp(var+ofs, "old"))
  60                return DIFF_FILE_OLD;
  61        if (!strcasecmp(var+ofs, "new"))
  62                return DIFF_FILE_NEW;
  63        if (!strcasecmp(var+ofs, "commit"))
  64                return DIFF_COMMIT;
  65        if (!strcasecmp(var+ofs, "whitespace"))
  66                return DIFF_WHITESPACE;
  67        if (!strcasecmp(var+ofs, "func"))
  68                return DIFF_FUNCINFO;
  69        return -1;
  70}
  71
  72static int parse_dirstat_params(struct diff_options *options, const char *params,
  73                                struct strbuf *errmsg)
  74{
  75        const char *p = params;
  76        int p_len, ret = 0;
  77
  78        while (*p) {
  79                p_len = strchrnul(p, ',') - p;
  80                if (!memcmp(p, "changes", p_len)) {
  81                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  82                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  83                } else if (!memcmp(p, "lines", p_len)) {
  84                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  85                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  86                } else if (!memcmp(p, "files", p_len)) {
  87                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  88                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  89                } else if (!memcmp(p, "noncumulative", p_len)) {
  90                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  91                } else if (!memcmp(p, "cumulative", p_len)) {
  92                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  93                } else if (isdigit(*p)) {
  94                        char *end;
  95                        int permille = strtoul(p, &end, 10) * 10;
  96                        if (*end == '.' && isdigit(*++end)) {
  97                                /* only use first digit */
  98                                permille += *end - '0';
  99                                /* .. and ignore any further digits */
 100                                while (isdigit(*++end))
 101                                        ; /* nothing */
 102                        }
 103                        if (end - p == p_len)
 104                                options->dirstat_permille = permille;
 105                        else {
 106                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%.*s'\n"),
 107                                            p_len, p);
 108                                ret++;
 109                        }
 110                } else {
 111                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%.*s'\n"),
 112                                    p_len, p);
 113                        ret++;
 114                }
 115
 116                p += p_len;
 117
 118                if (*p)
 119                        p++; /* more parameters, swallow separator */
 120        }
 121        return ret;
 122}
 123
 124static int git_config_rename(const char *var, const char *value)
 125{
 126        if (!value)
 127                return DIFF_DETECT_RENAME;
 128        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 129                return  DIFF_DETECT_COPY;
 130        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 131}
 132
 133/*
 134 * These are to give UI layer defaults.
 135 * The core-level commands such as git-diff-files should
 136 * never be affected by the setting of diff.renames
 137 * the user happens to have in the configuration file.
 138 */
 139int git_diff_ui_config(const char *var, const char *value, void *cb)
 140{
 141        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 142                diff_use_color_default = git_config_colorbool(var, value);
 143                return 0;
 144        }
 145        if (!strcmp(var, "diff.context")) {
 146                diff_context_default = git_config_int(var, value);
 147                if (diff_context_default < 0)
 148                        return -1;
 149                return 0;
 150        }
 151        if (!strcmp(var, "diff.renames")) {
 152                diff_detect_rename_default = git_config_rename(var, value);
 153                return 0;
 154        }
 155        if (!strcmp(var, "diff.autorefreshindex")) {
 156                diff_auto_refresh_index = git_config_bool(var, value);
 157                return 0;
 158        }
 159        if (!strcmp(var, "diff.mnemonicprefix")) {
 160                diff_mnemonic_prefix = git_config_bool(var, value);
 161                return 0;
 162        }
 163        if (!strcmp(var, "diff.noprefix")) {
 164                diff_no_prefix = git_config_bool(var, value);
 165                return 0;
 166        }
 167        if (!strcmp(var, "diff.statgraphwidth")) {
 168                diff_stat_graph_width = git_config_int(var, value);
 169                return 0;
 170        }
 171        if (!strcmp(var, "diff.external"))
 172                return git_config_string(&external_diff_cmd_cfg, var, value);
 173        if (!strcmp(var, "diff.wordregex"))
 174                return git_config_string(&diff_word_regex_cfg, var, value);
 175
 176        if (!strcmp(var, "diff.ignoresubmodules"))
 177                handle_ignore_submodules_arg(&default_diff_options, value);
 178
 179        if (git_color_config(var, value, cb) < 0)
 180                return -1;
 181
 182        return git_diff_basic_config(var, value, cb);
 183}
 184
 185int git_diff_basic_config(const char *var, const char *value, void *cb)
 186{
 187        if (!strcmp(var, "diff.renamelimit")) {
 188                diff_rename_limit_default = git_config_int(var, value);
 189                return 0;
 190        }
 191
 192        if (userdiff_config(var, value) < 0)
 193                return -1;
 194
 195        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 196                int slot = parse_diff_color_slot(var, 11);
 197                if (slot < 0)
 198                        return 0;
 199                if (!value)
 200                        return config_error_nonbool(var);
 201                color_parse(value, var, diff_colors[slot]);
 202                return 0;
 203        }
 204
 205        /* like GNU diff's --suppress-blank-empty option  */
 206        if (!strcmp(var, "diff.suppressblankempty") ||
 207                        /* for backwards compatibility */
 208                        !strcmp(var, "diff.suppress-blank-empty")) {
 209                diff_suppress_blank_empty = git_config_bool(var, value);
 210                return 0;
 211        }
 212
 213        if (!strcmp(var, "diff.dirstat")) {
 214                struct strbuf errmsg = STRBUF_INIT;
 215                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 216                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 217                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 218                                errmsg.buf);
 219                strbuf_release(&errmsg);
 220                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 221                return 0;
 222        }
 223
 224        if (!prefixcmp(var, "submodule."))
 225                return parse_submodule_config_option(var, value);
 226
 227        return git_default_config(var, value, cb);
 228}
 229
 230static char *quote_two(const char *one, const char *two)
 231{
 232        int need_one = quote_c_style(one, NULL, NULL, 1);
 233        int need_two = quote_c_style(two, NULL, NULL, 1);
 234        struct strbuf res = STRBUF_INIT;
 235
 236        if (need_one + need_two) {
 237                strbuf_addch(&res, '"');
 238                quote_c_style(one, &res, NULL, 1);
 239                quote_c_style(two, &res, NULL, 1);
 240                strbuf_addch(&res, '"');
 241        } else {
 242                strbuf_addstr(&res, one);
 243                strbuf_addstr(&res, two);
 244        }
 245        return strbuf_detach(&res, NULL);
 246}
 247
 248static const char *external_diff(void)
 249{
 250        static const char *external_diff_cmd = NULL;
 251        static int done_preparing = 0;
 252
 253        if (done_preparing)
 254                return external_diff_cmd;
 255        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 256        if (!external_diff_cmd)
 257                external_diff_cmd = external_diff_cmd_cfg;
 258        done_preparing = 1;
 259        return external_diff_cmd;
 260}
 261
 262static struct diff_tempfile {
 263        const char *name; /* filename external diff should read from */
 264        char hex[41];
 265        char mode[10];
 266        char tmp_path[PATH_MAX];
 267} diff_temp[2];
 268
 269typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 270
 271struct emit_callback {
 272        int color_diff;
 273        unsigned ws_rule;
 274        int blank_at_eof_in_preimage;
 275        int blank_at_eof_in_postimage;
 276        int lno_in_preimage;
 277        int lno_in_postimage;
 278        sane_truncate_fn truncate;
 279        const char **label_path;
 280        struct diff_words_data *diff_words;
 281        struct diff_options *opt;
 282        int *found_changesp;
 283        struct strbuf *header;
 284};
 285
 286static int count_lines(const char *data, int size)
 287{
 288        int count, ch, completely_empty = 1, nl_just_seen = 0;
 289        count = 0;
 290        while (0 < size--) {
 291                ch = *data++;
 292                if (ch == '\n') {
 293                        count++;
 294                        nl_just_seen = 1;
 295                        completely_empty = 0;
 296                }
 297                else {
 298                        nl_just_seen = 0;
 299                        completely_empty = 0;
 300                }
 301        }
 302        if (completely_empty)
 303                return 0;
 304        if (!nl_just_seen)
 305                count++; /* no trailing newline */
 306        return count;
 307}
 308
 309static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 310{
 311        if (!DIFF_FILE_VALID(one)) {
 312                mf->ptr = (char *)""; /* does not matter */
 313                mf->size = 0;
 314                return 0;
 315        }
 316        else if (diff_populate_filespec(one, 0))
 317                return -1;
 318
 319        mf->ptr = one->data;
 320        mf->size = one->size;
 321        return 0;
 322}
 323
 324/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 325static unsigned long diff_filespec_size(struct diff_filespec *one)
 326{
 327        if (!DIFF_FILE_VALID(one))
 328                return 0;
 329        diff_populate_filespec(one, 1);
 330        return one->size;
 331}
 332
 333static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 334{
 335        char *ptr = mf->ptr;
 336        long size = mf->size;
 337        int cnt = 0;
 338
 339        if (!size)
 340                return cnt;
 341        ptr += size - 1; /* pointing at the very end */
 342        if (*ptr != '\n')
 343                ; /* incomplete line */
 344        else
 345                ptr--; /* skip the last LF */
 346        while (mf->ptr < ptr) {
 347                char *prev_eol;
 348                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 349                        if (*prev_eol == '\n')
 350                                break;
 351                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 352                        break;
 353                cnt++;
 354                ptr = prev_eol - 1;
 355        }
 356        return cnt;
 357}
 358
 359static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 360                               struct emit_callback *ecbdata)
 361{
 362        int l1, l2, at;
 363        unsigned ws_rule = ecbdata->ws_rule;
 364        l1 = count_trailing_blank(mf1, ws_rule);
 365        l2 = count_trailing_blank(mf2, ws_rule);
 366        if (l2 <= l1) {
 367                ecbdata->blank_at_eof_in_preimage = 0;
 368                ecbdata->blank_at_eof_in_postimage = 0;
 369                return;
 370        }
 371        at = count_lines(mf1->ptr, mf1->size);
 372        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 373
 374        at = count_lines(mf2->ptr, mf2->size);
 375        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 376}
 377
 378static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 379                        int first, const char *line, int len)
 380{
 381        int has_trailing_newline, has_trailing_carriage_return;
 382        int nofirst;
 383        FILE *file = o->file;
 384
 385        if (o->output_prefix) {
 386                struct strbuf *msg = NULL;
 387                msg = o->output_prefix(o, o->output_prefix_data);
 388                assert(msg);
 389                fwrite(msg->buf, msg->len, 1, file);
 390        }
 391
 392        if (len == 0) {
 393                has_trailing_newline = (first == '\n');
 394                has_trailing_carriage_return = (!has_trailing_newline &&
 395                                                (first == '\r'));
 396                nofirst = has_trailing_newline || has_trailing_carriage_return;
 397        } else {
 398                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 399                if (has_trailing_newline)
 400                        len--;
 401                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 402                if (has_trailing_carriage_return)
 403                        len--;
 404                nofirst = 0;
 405        }
 406
 407        if (len || !nofirst) {
 408                fputs(set, file);
 409                if (!nofirst)
 410                        fputc(first, file);
 411                fwrite(line, len, 1, file);
 412                fputs(reset, file);
 413        }
 414        if (has_trailing_carriage_return)
 415                fputc('\r', file);
 416        if (has_trailing_newline)
 417                fputc('\n', file);
 418}
 419
 420static void emit_line(struct diff_options *o, const char *set, const char *reset,
 421                      const char *line, int len)
 422{
 423        emit_line_0(o, set, reset, line[0], line+1, len-1);
 424}
 425
 426static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 427{
 428        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 429              ecbdata->blank_at_eof_in_preimage &&
 430              ecbdata->blank_at_eof_in_postimage &&
 431              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 432              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 433                return 0;
 434        return ws_blank_line(line, len, ecbdata->ws_rule);
 435}
 436
 437static void emit_add_line(const char *reset,
 438                          struct emit_callback *ecbdata,
 439                          const char *line, int len)
 440{
 441        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 442        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 443
 444        if (!*ws)
 445                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 446        else if (new_blank_line_at_eof(ecbdata, line, len))
 447                /* Blank line at EOF - paint '+' as well */
 448                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 449        else {
 450                /* Emit just the prefix, then the rest. */
 451                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 452                ws_check_emit(line, len, ecbdata->ws_rule,
 453                              ecbdata->opt->file, set, reset, ws);
 454        }
 455}
 456
 457static void emit_hunk_header(struct emit_callback *ecbdata,
 458                             const char *line, int len)
 459{
 460        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 461        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 462        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 463        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 464        static const char atat[2] = { '@', '@' };
 465        const char *cp, *ep;
 466        struct strbuf msgbuf = STRBUF_INIT;
 467        int org_len = len;
 468        int i = 1;
 469
 470        /*
 471         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 472         * it always is at least 10 bytes long.
 473         */
 474        if (len < 10 ||
 475            memcmp(line, atat, 2) ||
 476            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 477                emit_line(ecbdata->opt, plain, reset, line, len);
 478                return;
 479        }
 480        ep += 2; /* skip over @@ */
 481
 482        /* The hunk header in fraginfo color */
 483        strbuf_add(&msgbuf, frag, strlen(frag));
 484        strbuf_add(&msgbuf, line, ep - line);
 485        strbuf_add(&msgbuf, reset, strlen(reset));
 486
 487        /*
 488         * trailing "\r\n"
 489         */
 490        for ( ; i < 3; i++)
 491                if (line[len - i] == '\r' || line[len - i] == '\n')
 492                        len--;
 493
 494        /* blank before the func header */
 495        for (cp = ep; ep - line < len; ep++)
 496                if (*ep != ' ' && *ep != '\t')
 497                        break;
 498        if (ep != cp) {
 499                strbuf_add(&msgbuf, plain, strlen(plain));
 500                strbuf_add(&msgbuf, cp, ep - cp);
 501                strbuf_add(&msgbuf, reset, strlen(reset));
 502        }
 503
 504        if (ep < line + len) {
 505                strbuf_add(&msgbuf, func, strlen(func));
 506                strbuf_add(&msgbuf, ep, line + len - ep);
 507                strbuf_add(&msgbuf, reset, strlen(reset));
 508        }
 509
 510        strbuf_add(&msgbuf, line + len, org_len - len);
 511        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 512        strbuf_release(&msgbuf);
 513}
 514
 515static struct diff_tempfile *claim_diff_tempfile(void) {
 516        int i;
 517        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 518                if (!diff_temp[i].name)
 519                        return diff_temp + i;
 520        die("BUG: diff is failing to clean up its tempfiles");
 521}
 522
 523static int remove_tempfile_installed;
 524
 525static void remove_tempfile(void)
 526{
 527        int i;
 528        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 529                if (diff_temp[i].name == diff_temp[i].tmp_path)
 530                        unlink_or_warn(diff_temp[i].name);
 531                diff_temp[i].name = NULL;
 532        }
 533}
 534
 535static void remove_tempfile_on_signal(int signo)
 536{
 537        remove_tempfile();
 538        sigchain_pop(signo);
 539        raise(signo);
 540}
 541
 542static void print_line_count(FILE *file, int count)
 543{
 544        switch (count) {
 545        case 0:
 546                fprintf(file, "0,0");
 547                break;
 548        case 1:
 549                fprintf(file, "1");
 550                break;
 551        default:
 552                fprintf(file, "1,%d", count);
 553                break;
 554        }
 555}
 556
 557static void emit_rewrite_lines(struct emit_callback *ecb,
 558                               int prefix, const char *data, int size)
 559{
 560        const char *endp = NULL;
 561        static const char *nneof = " No newline at end of file\n";
 562        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 563        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 564
 565        while (0 < size) {
 566                int len;
 567
 568                endp = memchr(data, '\n', size);
 569                len = endp ? (endp - data + 1) : size;
 570                if (prefix != '+') {
 571                        ecb->lno_in_preimage++;
 572                        emit_line_0(ecb->opt, old, reset, '-',
 573                                    data, len);
 574                } else {
 575                        ecb->lno_in_postimage++;
 576                        emit_add_line(reset, ecb, data, len);
 577                }
 578                size -= len;
 579                data += len;
 580        }
 581        if (!endp) {
 582                const char *plain = diff_get_color(ecb->color_diff,
 583                                                   DIFF_PLAIN);
 584                putc('\n', ecb->opt->file);
 585                emit_line_0(ecb->opt, plain, reset, '\\',
 586                            nneof, strlen(nneof));
 587        }
 588}
 589
 590static void emit_rewrite_diff(const char *name_a,
 591                              const char *name_b,
 592                              struct diff_filespec *one,
 593                              struct diff_filespec *two,
 594                              struct userdiff_driver *textconv_one,
 595                              struct userdiff_driver *textconv_two,
 596                              struct diff_options *o)
 597{
 598        int lc_a, lc_b;
 599        const char *name_a_tab, *name_b_tab;
 600        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 601        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 602        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 603        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 604        const char *a_prefix, *b_prefix;
 605        char *data_one, *data_two;
 606        size_t size_one, size_two;
 607        struct emit_callback ecbdata;
 608        char *line_prefix = "";
 609        struct strbuf *msgbuf;
 610
 611        if (o && o->output_prefix) {
 612                msgbuf = o->output_prefix(o, o->output_prefix_data);
 613                line_prefix = msgbuf->buf;
 614        }
 615
 616        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 617                a_prefix = o->b_prefix;
 618                b_prefix = o->a_prefix;
 619        } else {
 620                a_prefix = o->a_prefix;
 621                b_prefix = o->b_prefix;
 622        }
 623
 624        name_a += (*name_a == '/');
 625        name_b += (*name_b == '/');
 626        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 627        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 628
 629        strbuf_reset(&a_name);
 630        strbuf_reset(&b_name);
 631        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 632        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 633
 634        size_one = fill_textconv(textconv_one, one, &data_one);
 635        size_two = fill_textconv(textconv_two, two, &data_two);
 636
 637        memset(&ecbdata, 0, sizeof(ecbdata));
 638        ecbdata.color_diff = want_color(o->use_color);
 639        ecbdata.found_changesp = &o->found_changes;
 640        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 641        ecbdata.opt = o;
 642        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 643                mmfile_t mf1, mf2;
 644                mf1.ptr = (char *)data_one;
 645                mf2.ptr = (char *)data_two;
 646                mf1.size = size_one;
 647                mf2.size = size_two;
 648                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 649        }
 650        ecbdata.lno_in_preimage = 1;
 651        ecbdata.lno_in_postimage = 1;
 652
 653        lc_a = count_lines(data_one, size_one);
 654        lc_b = count_lines(data_two, size_two);
 655        fprintf(o->file,
 656                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 657                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 658                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 659                line_prefix, fraginfo);
 660        if (!o->irreversible_delete)
 661                print_line_count(o->file, lc_a);
 662        else
 663                fprintf(o->file, "?,?");
 664        fprintf(o->file, " +");
 665        print_line_count(o->file, lc_b);
 666        fprintf(o->file, " @@%s\n", reset);
 667        if (lc_a && !o->irreversible_delete)
 668                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 669        if (lc_b)
 670                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 671        if (textconv_one)
 672                free((char *)data_one);
 673        if (textconv_two)
 674                free((char *)data_two);
 675}
 676
 677struct diff_words_buffer {
 678        mmfile_t text;
 679        long alloc;
 680        struct diff_words_orig {
 681                const char *begin, *end;
 682        } *orig;
 683        int orig_nr, orig_alloc;
 684};
 685
 686static void diff_words_append(char *line, unsigned long len,
 687                struct diff_words_buffer *buffer)
 688{
 689        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 690        line++;
 691        len--;
 692        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 693        buffer->text.size += len;
 694        buffer->text.ptr[buffer->text.size] = '\0';
 695}
 696
 697struct diff_words_style_elem {
 698        const char *prefix;
 699        const char *suffix;
 700        const char *color; /* NULL; filled in by the setup code if
 701                            * color is enabled */
 702};
 703
 704struct diff_words_style {
 705        enum diff_words_type type;
 706        struct diff_words_style_elem new, old, ctx;
 707        const char *newline;
 708};
 709
 710static struct diff_words_style diff_words_styles[] = {
 711        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 712        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 713        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 714};
 715
 716struct diff_words_data {
 717        struct diff_words_buffer minus, plus;
 718        const char *current_plus;
 719        int last_minus;
 720        struct diff_options *opt;
 721        regex_t *word_regex;
 722        enum diff_words_type type;
 723        struct diff_words_style *style;
 724};
 725
 726static int fn_out_diff_words_write_helper(FILE *fp,
 727                                          struct diff_words_style_elem *st_el,
 728                                          const char *newline,
 729                                          size_t count, const char *buf,
 730                                          const char *line_prefix)
 731{
 732        int print = 0;
 733
 734        while (count) {
 735                char *p = memchr(buf, '\n', count);
 736                if (print)
 737                        fputs(line_prefix, fp);
 738                if (p != buf) {
 739                        if (st_el->color && fputs(st_el->color, fp) < 0)
 740                                return -1;
 741                        if (fputs(st_el->prefix, fp) < 0 ||
 742                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 743                            fputs(st_el->suffix, fp) < 0)
 744                                return -1;
 745                        if (st_el->color && *st_el->color
 746                            && fputs(GIT_COLOR_RESET, fp) < 0)
 747                                return -1;
 748                }
 749                if (!p)
 750                        return 0;
 751                if (fputs(newline, fp) < 0)
 752                        return -1;
 753                count -= p + 1 - buf;
 754                buf = p + 1;
 755                print = 1;
 756        }
 757        return 0;
 758}
 759
 760/*
 761 * '--color-words' algorithm can be described as:
 762 *
 763 *   1. collect a the minus/plus lines of a diff hunk, divided into
 764 *      minus-lines and plus-lines;
 765 *
 766 *   2. break both minus-lines and plus-lines into words and
 767 *      place them into two mmfile_t with one word for each line;
 768 *
 769 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 770 *
 771 * And for the common parts of the both file, we output the plus side text.
 772 * diff_words->current_plus is used to trace the current position of the plus file
 773 * which printed. diff_words->last_minus is used to trace the last minus word
 774 * printed.
 775 *
 776 * For '--graph' to work with '--color-words', we need to output the graph prefix
 777 * on each line of color words output. Generally, there are two conditions on
 778 * which we should output the prefix.
 779 *
 780 *   1. diff_words->last_minus == 0 &&
 781 *      diff_words->current_plus == diff_words->plus.text.ptr
 782 *
 783 *      that is: the plus text must start as a new line, and if there is no minus
 784 *      word printed, a graph prefix must be printed.
 785 *
 786 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 787 *      *(diff_words->current_plus - 1) == '\n'
 788 *
 789 *      that is: a graph prefix must be printed following a '\n'
 790 */
 791static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 792{
 793        if ((diff_words->last_minus == 0 &&
 794                diff_words->current_plus == diff_words->plus.text.ptr) ||
 795                (diff_words->current_plus > diff_words->plus.text.ptr &&
 796                *(diff_words->current_plus - 1) == '\n')) {
 797                return 1;
 798        } else {
 799                return 0;
 800        }
 801}
 802
 803static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 804{
 805        struct diff_words_data *diff_words = priv;
 806        struct diff_words_style *style = diff_words->style;
 807        int minus_first, minus_len, plus_first, plus_len;
 808        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 809        struct diff_options *opt = diff_words->opt;
 810        struct strbuf *msgbuf;
 811        char *line_prefix = "";
 812
 813        if (line[0] != '@' || parse_hunk_header(line, len,
 814                        &minus_first, &minus_len, &plus_first, &plus_len))
 815                return;
 816
 817        assert(opt);
 818        if (opt->output_prefix) {
 819                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 820                line_prefix = msgbuf->buf;
 821        }
 822
 823        /* POSIX requires that first be decremented by one if len == 0... */
 824        if (minus_len) {
 825                minus_begin = diff_words->minus.orig[minus_first].begin;
 826                minus_end =
 827                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 828        } else
 829                minus_begin = minus_end =
 830                        diff_words->minus.orig[minus_first].end;
 831
 832        if (plus_len) {
 833                plus_begin = diff_words->plus.orig[plus_first].begin;
 834                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 835        } else
 836                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 837
 838        if (color_words_output_graph_prefix(diff_words)) {
 839                fputs(line_prefix, diff_words->opt->file);
 840        }
 841        if (diff_words->current_plus != plus_begin) {
 842                fn_out_diff_words_write_helper(diff_words->opt->file,
 843                                &style->ctx, style->newline,
 844                                plus_begin - diff_words->current_plus,
 845                                diff_words->current_plus, line_prefix);
 846                if (*(plus_begin - 1) == '\n')
 847                        fputs(line_prefix, diff_words->opt->file);
 848        }
 849        if (minus_begin != minus_end) {
 850                fn_out_diff_words_write_helper(diff_words->opt->file,
 851                                &style->old, style->newline,
 852                                minus_end - minus_begin, minus_begin,
 853                                line_prefix);
 854        }
 855        if (plus_begin != plus_end) {
 856                fn_out_diff_words_write_helper(diff_words->opt->file,
 857                                &style->new, style->newline,
 858                                plus_end - plus_begin, plus_begin,
 859                                line_prefix);
 860        }
 861
 862        diff_words->current_plus = plus_end;
 863        diff_words->last_minus = minus_first;
 864}
 865
 866/* This function starts looking at *begin, and returns 0 iff a word was found. */
 867static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 868                int *begin, int *end)
 869{
 870        if (word_regex && *begin < buffer->size) {
 871                regmatch_t match[1];
 872                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 873                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 874                                        '\n', match[0].rm_eo - match[0].rm_so);
 875                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 876                        *begin += match[0].rm_so;
 877                        return *begin >= *end;
 878                }
 879                return -1;
 880        }
 881
 882        /* find the next word */
 883        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 884                (*begin)++;
 885        if (*begin >= buffer->size)
 886                return -1;
 887
 888        /* find the end of the word */
 889        *end = *begin + 1;
 890        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 891                (*end)++;
 892
 893        return 0;
 894}
 895
 896/*
 897 * This function splits the words in buffer->text, stores the list with
 898 * newline separator into out, and saves the offsets of the original words
 899 * in buffer->orig.
 900 */
 901static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 902                regex_t *word_regex)
 903{
 904        int i, j;
 905        long alloc = 0;
 906
 907        out->size = 0;
 908        out->ptr = NULL;
 909
 910        /* fake an empty "0th" word */
 911        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 912        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 913        buffer->orig_nr = 1;
 914
 915        for (i = 0; i < buffer->text.size; i++) {
 916                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 917                        return;
 918
 919                /* store original boundaries */
 920                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 921                                buffer->orig_alloc);
 922                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 923                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 924                buffer->orig_nr++;
 925
 926                /* store one word */
 927                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 928                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 929                out->ptr[out->size + j - i] = '\n';
 930                out->size += j - i + 1;
 931
 932                i = j - 1;
 933        }
 934}
 935
 936/* this executes the word diff on the accumulated buffers */
 937static void diff_words_show(struct diff_words_data *diff_words)
 938{
 939        xpparam_t xpp;
 940        xdemitconf_t xecfg;
 941        mmfile_t minus, plus;
 942        struct diff_words_style *style = diff_words->style;
 943
 944        struct diff_options *opt = diff_words->opt;
 945        struct strbuf *msgbuf;
 946        char *line_prefix = "";
 947
 948        assert(opt);
 949        if (opt->output_prefix) {
 950                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 951                line_prefix = msgbuf->buf;
 952        }
 953
 954        /* special case: only removal */
 955        if (!diff_words->plus.text.size) {
 956                fputs(line_prefix, diff_words->opt->file);
 957                fn_out_diff_words_write_helper(diff_words->opt->file,
 958                        &style->old, style->newline,
 959                        diff_words->minus.text.size,
 960                        diff_words->minus.text.ptr, line_prefix);
 961                diff_words->minus.text.size = 0;
 962                return;
 963        }
 964
 965        diff_words->current_plus = diff_words->plus.text.ptr;
 966        diff_words->last_minus = 0;
 967
 968        memset(&xpp, 0, sizeof(xpp));
 969        memset(&xecfg, 0, sizeof(xecfg));
 970        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 971        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 972        xpp.flags = 0;
 973        /* as only the hunk header will be parsed, we need a 0-context */
 974        xecfg.ctxlen = 0;
 975        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 976                      &xpp, &xecfg);
 977        free(minus.ptr);
 978        free(plus.ptr);
 979        if (diff_words->current_plus != diff_words->plus.text.ptr +
 980                        diff_words->plus.text.size) {
 981                if (color_words_output_graph_prefix(diff_words))
 982                        fputs(line_prefix, diff_words->opt->file);
 983                fn_out_diff_words_write_helper(diff_words->opt->file,
 984                        &style->ctx, style->newline,
 985                        diff_words->plus.text.ptr + diff_words->plus.text.size
 986                        - diff_words->current_plus, diff_words->current_plus,
 987                        line_prefix);
 988        }
 989        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 990}
 991
 992/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 993static void diff_words_flush(struct emit_callback *ecbdata)
 994{
 995        if (ecbdata->diff_words->minus.text.size ||
 996            ecbdata->diff_words->plus.text.size)
 997                diff_words_show(ecbdata->diff_words);
 998}
 999
1000static void diff_filespec_load_driver(struct diff_filespec *one)
1001{
1002        /* Use already-loaded driver */
1003        if (one->driver)
1004                return;
1005
1006        if (S_ISREG(one->mode))
1007                one->driver = userdiff_find_by_path(one->path);
1008
1009        /* Fallback to default settings */
1010        if (!one->driver)
1011                one->driver = userdiff_find_by_name("default");
1012}
1013
1014static const char *userdiff_word_regex(struct diff_filespec *one)
1015{
1016        diff_filespec_load_driver(one);
1017        return one->driver->word_regex;
1018}
1019
1020static void init_diff_words_data(struct emit_callback *ecbdata,
1021                                 struct diff_options *orig_opts,
1022                                 struct diff_filespec *one,
1023                                 struct diff_filespec *two)
1024{
1025        int i;
1026        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1027        memcpy(o, orig_opts, sizeof(struct diff_options));
1028
1029        ecbdata->diff_words =
1030                xcalloc(1, sizeof(struct diff_words_data));
1031        ecbdata->diff_words->type = o->word_diff;
1032        ecbdata->diff_words->opt = o;
1033        if (!o->word_regex)
1034                o->word_regex = userdiff_word_regex(one);
1035        if (!o->word_regex)
1036                o->word_regex = userdiff_word_regex(two);
1037        if (!o->word_regex)
1038                o->word_regex = diff_word_regex_cfg;
1039        if (o->word_regex) {
1040                ecbdata->diff_words->word_regex = (regex_t *)
1041                        xmalloc(sizeof(regex_t));
1042                if (regcomp(ecbdata->diff_words->word_regex,
1043                            o->word_regex,
1044                            REG_EXTENDED | REG_NEWLINE))
1045                        die ("Invalid regular expression: %s",
1046                             o->word_regex);
1047        }
1048        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1049                if (o->word_diff == diff_words_styles[i].type) {
1050                        ecbdata->diff_words->style =
1051                                &diff_words_styles[i];
1052                        break;
1053                }
1054        }
1055        if (want_color(o->use_color)) {
1056                struct diff_words_style *st = ecbdata->diff_words->style;
1057                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1058                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1059                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1060        }
1061}
1062
1063static void free_diff_words_data(struct emit_callback *ecbdata)
1064{
1065        if (ecbdata->diff_words) {
1066                diff_words_flush(ecbdata);
1067                free (ecbdata->diff_words->opt);
1068                free (ecbdata->diff_words->minus.text.ptr);
1069                free (ecbdata->diff_words->minus.orig);
1070                free (ecbdata->diff_words->plus.text.ptr);
1071                free (ecbdata->diff_words->plus.orig);
1072                if (ecbdata->diff_words->word_regex) {
1073                        regfree(ecbdata->diff_words->word_regex);
1074                        free(ecbdata->diff_words->word_regex);
1075                }
1076                free(ecbdata->diff_words);
1077                ecbdata->diff_words = NULL;
1078        }
1079}
1080
1081const char *diff_get_color(int diff_use_color, enum color_diff ix)
1082{
1083        if (want_color(diff_use_color))
1084                return diff_colors[ix];
1085        return "";
1086}
1087
1088static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1089{
1090        const char *cp;
1091        unsigned long allot;
1092        size_t l = len;
1093
1094        if (ecb->truncate)
1095                return ecb->truncate(line, len);
1096        cp = line;
1097        allot = l;
1098        while (0 < l) {
1099                (void) utf8_width(&cp, &l);
1100                if (!cp)
1101                        break; /* truncated in the middle? */
1102        }
1103        return allot - l;
1104}
1105
1106static void find_lno(const char *line, struct emit_callback *ecbdata)
1107{
1108        const char *p;
1109        ecbdata->lno_in_preimage = 0;
1110        ecbdata->lno_in_postimage = 0;
1111        p = strchr(line, '-');
1112        if (!p)
1113                return; /* cannot happen */
1114        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1115        p = strchr(p, '+');
1116        if (!p)
1117                return; /* cannot happen */
1118        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1119}
1120
1121static void fn_out_consume(void *priv, char *line, unsigned long len)
1122{
1123        struct emit_callback *ecbdata = priv;
1124        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1125        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1126        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1127        struct diff_options *o = ecbdata->opt;
1128        char *line_prefix = "";
1129        struct strbuf *msgbuf;
1130
1131        if (o && o->output_prefix) {
1132                msgbuf = o->output_prefix(o, o->output_prefix_data);
1133                line_prefix = msgbuf->buf;
1134        }
1135
1136        if (ecbdata->header) {
1137                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1138                strbuf_reset(ecbdata->header);
1139                ecbdata->header = NULL;
1140        }
1141        *(ecbdata->found_changesp) = 1;
1142
1143        if (ecbdata->label_path[0]) {
1144                const char *name_a_tab, *name_b_tab;
1145
1146                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1147                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1148
1149                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1150                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1151                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1152                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1153                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1154        }
1155
1156        if (diff_suppress_blank_empty
1157            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1158                line[0] = '\n';
1159                len = 1;
1160        }
1161
1162        if (line[0] == '@') {
1163                if (ecbdata->diff_words)
1164                        diff_words_flush(ecbdata);
1165                len = sane_truncate_line(ecbdata, line, len);
1166                find_lno(line, ecbdata);
1167                emit_hunk_header(ecbdata, line, len);
1168                if (line[len-1] != '\n')
1169                        putc('\n', ecbdata->opt->file);
1170                return;
1171        }
1172
1173        if (len < 1) {
1174                emit_line(ecbdata->opt, reset, reset, line, len);
1175                if (ecbdata->diff_words
1176                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1177                        fputs("~\n", ecbdata->opt->file);
1178                return;
1179        }
1180
1181        if (ecbdata->diff_words) {
1182                if (line[0] == '-') {
1183                        diff_words_append(line, len,
1184                                          &ecbdata->diff_words->minus);
1185                        return;
1186                } else if (line[0] == '+') {
1187                        diff_words_append(line, len,
1188                                          &ecbdata->diff_words->plus);
1189                        return;
1190                } else if (!prefixcmp(line, "\\ ")) {
1191                        /*
1192                         * Eat the "no newline at eof" marker as if we
1193                         * saw a "+" or "-" line with nothing on it,
1194                         * and return without diff_words_flush() to
1195                         * defer processing. If this is the end of
1196                         * preimage, more "+" lines may come after it.
1197                         */
1198                        return;
1199                }
1200                diff_words_flush(ecbdata);
1201                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1202                        emit_line(ecbdata->opt, plain, reset, line, len);
1203                        fputs("~\n", ecbdata->opt->file);
1204                } else {
1205                        /*
1206                         * Skip the prefix character, if any.  With
1207                         * diff_suppress_blank_empty, there may be
1208                         * none.
1209                         */
1210                        if (line[0] != '\n') {
1211                              line++;
1212                              len--;
1213                        }
1214                        emit_line(ecbdata->opt, plain, reset, line, len);
1215                }
1216                return;
1217        }
1218
1219        if (line[0] != '+') {
1220                const char *color =
1221                        diff_get_color(ecbdata->color_diff,
1222                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1223                ecbdata->lno_in_preimage++;
1224                if (line[0] == ' ')
1225                        ecbdata->lno_in_postimage++;
1226                emit_line(ecbdata->opt, color, reset, line, len);
1227        } else {
1228                ecbdata->lno_in_postimage++;
1229                emit_add_line(reset, ecbdata, line + 1, len - 1);
1230        }
1231}
1232
1233static char *pprint_rename(const char *a, const char *b)
1234{
1235        const char *old = a;
1236        const char *new = b;
1237        struct strbuf name = STRBUF_INIT;
1238        int pfx_length, sfx_length;
1239        int len_a = strlen(a);
1240        int len_b = strlen(b);
1241        int a_midlen, b_midlen;
1242        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1243        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1244
1245        if (qlen_a || qlen_b) {
1246                quote_c_style(a, &name, NULL, 0);
1247                strbuf_addstr(&name, " => ");
1248                quote_c_style(b, &name, NULL, 0);
1249                return strbuf_detach(&name, NULL);
1250        }
1251
1252        /* Find common prefix */
1253        pfx_length = 0;
1254        while (*old && *new && *old == *new) {
1255                if (*old == '/')
1256                        pfx_length = old - a + 1;
1257                old++;
1258                new++;
1259        }
1260
1261        /* Find common suffix */
1262        old = a + len_a;
1263        new = b + len_b;
1264        sfx_length = 0;
1265        while (a <= old && b <= new && *old == *new) {
1266                if (*old == '/')
1267                        sfx_length = len_a - (old - a);
1268                old--;
1269                new--;
1270        }
1271
1272        /*
1273         * pfx{mid-a => mid-b}sfx
1274         * {pfx-a => pfx-b}sfx
1275         * pfx{sfx-a => sfx-b}
1276         * name-a => name-b
1277         */
1278        a_midlen = len_a - pfx_length - sfx_length;
1279        b_midlen = len_b - pfx_length - sfx_length;
1280        if (a_midlen < 0)
1281                a_midlen = 0;
1282        if (b_midlen < 0)
1283                b_midlen = 0;
1284
1285        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1286        if (pfx_length + sfx_length) {
1287                strbuf_add(&name, a, pfx_length);
1288                strbuf_addch(&name, '{');
1289        }
1290        strbuf_add(&name, a + pfx_length, a_midlen);
1291        strbuf_addstr(&name, " => ");
1292        strbuf_add(&name, b + pfx_length, b_midlen);
1293        if (pfx_length + sfx_length) {
1294                strbuf_addch(&name, '}');
1295                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1296        }
1297        return strbuf_detach(&name, NULL);
1298}
1299
1300struct diffstat_t {
1301        int nr;
1302        int alloc;
1303        struct diffstat_file {
1304                char *from_name;
1305                char *name;
1306                char *print_name;
1307                unsigned is_unmerged:1;
1308                unsigned is_binary:1;
1309                unsigned is_renamed:1;
1310                uintmax_t added, deleted;
1311        } **files;
1312};
1313
1314static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1315                                          const char *name_a,
1316                                          const char *name_b)
1317{
1318        struct diffstat_file *x;
1319        x = xcalloc(sizeof (*x), 1);
1320        if (diffstat->nr == diffstat->alloc) {
1321                diffstat->alloc = alloc_nr(diffstat->alloc);
1322                diffstat->files = xrealloc(diffstat->files,
1323                                diffstat->alloc * sizeof(x));
1324        }
1325        diffstat->files[diffstat->nr++] = x;
1326        if (name_b) {
1327                x->from_name = xstrdup(name_a);
1328                x->name = xstrdup(name_b);
1329                x->is_renamed = 1;
1330        }
1331        else {
1332                x->from_name = NULL;
1333                x->name = xstrdup(name_a);
1334        }
1335        return x;
1336}
1337
1338static void diffstat_consume(void *priv, char *line, unsigned long len)
1339{
1340        struct diffstat_t *diffstat = priv;
1341        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1342
1343        if (line[0] == '+')
1344                x->added++;
1345        else if (line[0] == '-')
1346                x->deleted++;
1347}
1348
1349const char mime_boundary_leader[] = "------------";
1350
1351static int scale_linear(int it, int width, int max_change)
1352{
1353        if (!it)
1354                return 0;
1355        /*
1356         * make sure that at least one '-' or '+' is printed if
1357         * there is any change to this path. The easiest way is to
1358         * scale linearly as if the alloted width is one column shorter
1359         * than it is, and then add 1 to the result.
1360         */
1361        return 1 + (it * (width - 1) / max_change);
1362}
1363
1364static void show_name(FILE *file,
1365                      const char *prefix, const char *name, int len)
1366{
1367        fprintf(file, " %s%-*s |", prefix, len, name);
1368}
1369
1370static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1371{
1372        if (cnt <= 0)
1373                return;
1374        fprintf(file, "%s", set);
1375        while (cnt--)
1376                putc(ch, file);
1377        fprintf(file, "%s", reset);
1378}
1379
1380static void fill_print_name(struct diffstat_file *file)
1381{
1382        char *pname;
1383
1384        if (file->print_name)
1385                return;
1386
1387        if (!file->is_renamed) {
1388                struct strbuf buf = STRBUF_INIT;
1389                if (quote_c_style(file->name, &buf, NULL, 0)) {
1390                        pname = strbuf_detach(&buf, NULL);
1391                } else {
1392                        pname = file->name;
1393                        strbuf_release(&buf);
1394                }
1395        } else {
1396                pname = pprint_rename(file->from_name, file->name);
1397        }
1398        file->print_name = pname;
1399}
1400
1401int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1402{
1403        struct strbuf sb = STRBUF_INIT;
1404        int ret;
1405
1406        if (!files) {
1407                assert(insertions == 0 && deletions == 0);
1408                return fprintf(fp, "%s\n", " 0 files changed");
1409        }
1410
1411        strbuf_addf(&sb,
1412                    (files == 1) ? " %d file changed" : " %d files changed",
1413                    files);
1414
1415        /*
1416         * For binary diff, the caller may want to print "x files
1417         * changed" with insertions == 0 && deletions == 0.
1418         *
1419         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1420         * is probably less confusing (i.e skip over "2 files changed
1421         * but nothing about added/removed lines? Is this a bug in Git?").
1422         */
1423        if (insertions || deletions == 0) {
1424                /*
1425                 * TRANSLATORS: "+" in (+) is a line addition marker;
1426                 * do not translate it.
1427                 */
1428                strbuf_addf(&sb,
1429                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1430                            insertions);
1431        }
1432
1433        if (deletions || insertions == 0) {
1434                /*
1435                 * TRANSLATORS: "-" in (-) is a line removal marker;
1436                 * do not translate it.
1437                 */
1438                strbuf_addf(&sb,
1439                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1440                            deletions);
1441        }
1442        strbuf_addch(&sb, '\n');
1443        ret = fputs(sb.buf, fp);
1444        strbuf_release(&sb);
1445        return ret;
1446}
1447
1448static void show_stats(struct diffstat_t *data, struct diff_options *options)
1449{
1450        int i, len, add, del, adds = 0, dels = 0;
1451        uintmax_t max_change = 0, max_len = 0;
1452        int total_files = data->nr, count;
1453        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1454        const char *reset, *add_c, *del_c;
1455        const char *line_prefix = "";
1456        int extra_shown = 0;
1457        struct strbuf *msg = NULL;
1458
1459        if (data->nr == 0)
1460                return;
1461
1462        if (options->output_prefix) {
1463                msg = options->output_prefix(options, options->output_prefix_data);
1464                line_prefix = msg->buf;
1465        }
1466
1467        count = options->stat_count ? options->stat_count : data->nr;
1468
1469        reset = diff_get_color_opt(options, DIFF_RESET);
1470        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1471        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1472
1473        /*
1474         * Find the longest filename and max number of changes
1475         */
1476        for (i = 0; (i < count) && (i < data->nr); i++) {
1477                struct diffstat_file *file = data->files[i];
1478                uintmax_t change = file->added + file->deleted;
1479                if (!data->files[i]->is_renamed &&
1480                         (change == 0)) {
1481                        count++; /* not shown == room for one more */
1482                        continue;
1483                }
1484                fill_print_name(file);
1485                len = strlen(file->print_name);
1486                if (max_len < len)
1487                        max_len = len;
1488
1489                if (file->is_unmerged) {
1490                        /* "Unmerged" is 8 characters */
1491                        bin_width = bin_width < 8 ? 8 : bin_width;
1492                        continue;
1493                }
1494                if (file->is_binary) {
1495                        /* "Bin XXX -> YYY bytes" */
1496                        int w = 14 + decimal_width(file->added)
1497                                + decimal_width(file->deleted);
1498                        bin_width = bin_width < w ? w : bin_width;
1499                        /* Display change counts aligned with "Bin" */
1500                        number_width = 3;
1501                        continue;
1502                }
1503
1504                if (max_change < change)
1505                        max_change = change;
1506        }
1507        count = i; /* min(count, data->nr) */
1508
1509        /*
1510         * We have width = stat_width or term_columns() columns total.
1511         * We want a maximum of min(max_len, stat_name_width) for the name part.
1512         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1513         * We also need 1 for " " and 4 + decimal_width(max_change)
1514         * for " | NNNN " and one the empty column at the end, altogether
1515         * 6 + decimal_width(max_change).
1516         *
1517         * If there's not enough space, we will use the smaller of
1518         * stat_name_width (if set) and 5/8*width for the filename,
1519         * and the rest for constant elements + graph part, but no more
1520         * than stat_graph_width for the graph part.
1521         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1522         * for the standard terminal size).
1523         *
1524         * In other words: stat_width limits the maximum width, and
1525         * stat_name_width fixes the maximum width of the filename,
1526         * and is also used to divide available columns if there
1527         * aren't enough.
1528         *
1529         * Binary files are displayed with "Bin XXX -> YYY bytes"
1530         * instead of the change count and graph. This part is treated
1531         * similarly to the graph part, except that it is not
1532         * "scaled". If total width is too small to accomodate the
1533         * guaranteed minimum width of the filename part and the
1534         * separators and this message, this message will "overflow"
1535         * making the line longer than the maximum width.
1536         */
1537
1538        if (options->stat_width == -1)
1539                width = term_columns() - options->output_prefix_length;
1540        else
1541                width = options->stat_width ? options->stat_width : 80;
1542        number_width = decimal_width(max_change) > number_width ?
1543                decimal_width(max_change) : number_width;
1544
1545        if (options->stat_graph_width == -1)
1546                options->stat_graph_width = diff_stat_graph_width;
1547
1548        /*
1549         * Guarantee 3/8*16==6 for the graph part
1550         * and 5/8*16==10 for the filename part
1551         */
1552        if (width < 16 + 6 + number_width)
1553                width = 16 + 6 + number_width;
1554
1555        /*
1556         * First assign sizes that are wanted, ignoring available width.
1557         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1558         * starting from "XXX" should fit in graph_width.
1559         */
1560        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1561        if (options->stat_graph_width &&
1562            options->stat_graph_width < graph_width)
1563                graph_width = options->stat_graph_width;
1564
1565        name_width = (options->stat_name_width > 0 &&
1566                      options->stat_name_width < max_len) ?
1567                options->stat_name_width : max_len;
1568
1569        /*
1570         * Adjust adjustable widths not to exceed maximum width
1571         */
1572        if (name_width + number_width + 6 + graph_width > width) {
1573                if (graph_width > width * 3/8 - number_width - 6) {
1574                        graph_width = width * 3/8 - number_width - 6;
1575                        if (graph_width < 6)
1576                                graph_width = 6;
1577                }
1578
1579                if (options->stat_graph_width &&
1580                    graph_width > options->stat_graph_width)
1581                        graph_width = options->stat_graph_width;
1582                if (name_width > width - number_width - 6 - graph_width)
1583                        name_width = width - number_width - 6 - graph_width;
1584                else
1585                        graph_width = width - number_width - 6 - name_width;
1586        }
1587
1588        /*
1589         * From here name_width is the width of the name area,
1590         * and graph_width is the width of the graph area.
1591         * max_change is used to scale graph properly.
1592         */
1593        for (i = 0; i < count; i++) {
1594                const char *prefix = "";
1595                char *name = data->files[i]->print_name;
1596                uintmax_t added = data->files[i]->added;
1597                uintmax_t deleted = data->files[i]->deleted;
1598                int name_len;
1599
1600                if (!data->files[i]->is_renamed &&
1601                         (added + deleted == 0)) {
1602                        total_files--;
1603                        continue;
1604                }
1605                /*
1606                 * "scale" the filename
1607                 */
1608                len = name_width;
1609                name_len = strlen(name);
1610                if (name_width < name_len) {
1611                        char *slash;
1612                        prefix = "...";
1613                        len -= 3;
1614                        name += name_len - len;
1615                        slash = strchr(name, '/');
1616                        if (slash)
1617                                name = slash;
1618                }
1619
1620                if (data->files[i]->is_binary) {
1621                        fprintf(options->file, "%s", line_prefix);
1622                        show_name(options->file, prefix, name, len);
1623                        fprintf(options->file, " %*s", number_width, "Bin");
1624                        if (!added && !deleted) {
1625                                putc('\n', options->file);
1626                                continue;
1627                        }
1628                        fprintf(options->file, " %s%"PRIuMAX"%s",
1629                                del_c, deleted, reset);
1630                        fprintf(options->file, " -> ");
1631                        fprintf(options->file, "%s%"PRIuMAX"%s",
1632                                add_c, added, reset);
1633                        fprintf(options->file, " bytes");
1634                        fprintf(options->file, "\n");
1635                        continue;
1636                }
1637                else if (data->files[i]->is_unmerged) {
1638                        fprintf(options->file, "%s", line_prefix);
1639                        show_name(options->file, prefix, name, len);
1640                        fprintf(options->file, " Unmerged\n");
1641                        continue;
1642                }
1643
1644                /*
1645                 * scale the add/delete
1646                 */
1647                add = added;
1648                del = deleted;
1649                adds += add;
1650                dels += del;
1651
1652                if (graph_width <= max_change) {
1653                        int total = add + del;
1654
1655                        total = scale_linear(add + del, graph_width, max_change);
1656                        if (total < 2 && add && del)
1657                                /* width >= 2 due to the sanity check */
1658                                total = 2;
1659                        if (add < del) {
1660                                add = scale_linear(add, graph_width, max_change);
1661                                del = total - add;
1662                        } else {
1663                                del = scale_linear(del, graph_width, max_change);
1664                                add = total - del;
1665                        }
1666                }
1667                fprintf(options->file, "%s", line_prefix);
1668                show_name(options->file, prefix, name, len);
1669                fprintf(options->file, " %*"PRIuMAX"%s",
1670                        number_width, added + deleted,
1671                        added + deleted ? " " : "");
1672                show_graph(options->file, '+', add, add_c, reset);
1673                show_graph(options->file, '-', del, del_c, reset);
1674                fprintf(options->file, "\n");
1675        }
1676        for (i = count; i < data->nr; i++) {
1677                uintmax_t added = data->files[i]->added;
1678                uintmax_t deleted = data->files[i]->deleted;
1679                if (!data->files[i]->is_renamed &&
1680                         (added + deleted == 0)) {
1681                        total_files--;
1682                        continue;
1683                }
1684                adds += added;
1685                dels += deleted;
1686                if (!extra_shown)
1687                        fprintf(options->file, "%s ...\n", line_prefix);
1688                extra_shown = 1;
1689        }
1690        fprintf(options->file, "%s", line_prefix);
1691        print_stat_summary(options->file, total_files, adds, dels);
1692}
1693
1694static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1695{
1696        int i, adds = 0, dels = 0, total_files = data->nr;
1697
1698        if (data->nr == 0)
1699                return;
1700
1701        for (i = 0; i < data->nr; i++) {
1702                int added = data->files[i]->added;
1703                int deleted= data->files[i]->deleted;
1704
1705                if (data->files[i]->is_unmerged)
1706                        continue;
1707                if (!data->files[i]->is_renamed && (added + deleted == 0)) {
1708                        total_files--;
1709                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1710                        adds += added;
1711                        dels += deleted;
1712                }
1713        }
1714        if (options->output_prefix) {
1715                struct strbuf *msg = NULL;
1716                msg = options->output_prefix(options,
1717                                options->output_prefix_data);
1718                fprintf(options->file, "%s", msg->buf);
1719        }
1720        print_stat_summary(options->file, total_files, adds, dels);
1721}
1722
1723static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1724{
1725        int i;
1726
1727        if (data->nr == 0)
1728                return;
1729
1730        for (i = 0; i < data->nr; i++) {
1731                struct diffstat_file *file = data->files[i];
1732
1733                if (options->output_prefix) {
1734                        struct strbuf *msg = NULL;
1735                        msg = options->output_prefix(options,
1736                                        options->output_prefix_data);
1737                        fprintf(options->file, "%s", msg->buf);
1738                }
1739
1740                if (file->is_binary)
1741                        fprintf(options->file, "-\t-\t");
1742                else
1743                        fprintf(options->file,
1744                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1745                                file->added, file->deleted);
1746                if (options->line_termination) {
1747                        fill_print_name(file);
1748                        if (!file->is_renamed)
1749                                write_name_quoted(file->name, options->file,
1750                                                  options->line_termination);
1751                        else {
1752                                fputs(file->print_name, options->file);
1753                                putc(options->line_termination, options->file);
1754                        }
1755                } else {
1756                        if (file->is_renamed) {
1757                                putc('\0', options->file);
1758                                write_name_quoted(file->from_name, options->file, '\0');
1759                        }
1760                        write_name_quoted(file->name, options->file, '\0');
1761                }
1762        }
1763}
1764
1765struct dirstat_file {
1766        const char *name;
1767        unsigned long changed;
1768};
1769
1770struct dirstat_dir {
1771        struct dirstat_file *files;
1772        int alloc, nr, permille, cumulative;
1773};
1774
1775static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1776                unsigned long changed, const char *base, int baselen)
1777{
1778        unsigned long this_dir = 0;
1779        unsigned int sources = 0;
1780        const char *line_prefix = "";
1781        struct strbuf *msg = NULL;
1782
1783        if (opt->output_prefix) {
1784                msg = opt->output_prefix(opt, opt->output_prefix_data);
1785                line_prefix = msg->buf;
1786        }
1787
1788        while (dir->nr) {
1789                struct dirstat_file *f = dir->files;
1790                int namelen = strlen(f->name);
1791                unsigned long this;
1792                char *slash;
1793
1794                if (namelen < baselen)
1795                        break;
1796                if (memcmp(f->name, base, baselen))
1797                        break;
1798                slash = strchr(f->name + baselen, '/');
1799                if (slash) {
1800                        int newbaselen = slash + 1 - f->name;
1801                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1802                        sources++;
1803                } else {
1804                        this = f->changed;
1805                        dir->files++;
1806                        dir->nr--;
1807                        sources += 2;
1808                }
1809                this_dir += this;
1810        }
1811
1812        /*
1813         * We don't report dirstat's for
1814         *  - the top level
1815         *  - or cases where everything came from a single directory
1816         *    under this directory (sources == 1).
1817         */
1818        if (baselen && sources != 1) {
1819                if (this_dir) {
1820                        int permille = this_dir * 1000 / changed;
1821                        if (permille >= dir->permille) {
1822                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1823                                        permille / 10, permille % 10, baselen, base);
1824                                if (!dir->cumulative)
1825                                        return 0;
1826                        }
1827                }
1828        }
1829        return this_dir;
1830}
1831
1832static int dirstat_compare(const void *_a, const void *_b)
1833{
1834        const struct dirstat_file *a = _a;
1835        const struct dirstat_file *b = _b;
1836        return strcmp(a->name, b->name);
1837}
1838
1839static void show_dirstat(struct diff_options *options)
1840{
1841        int i;
1842        unsigned long changed;
1843        struct dirstat_dir dir;
1844        struct diff_queue_struct *q = &diff_queued_diff;
1845
1846        dir.files = NULL;
1847        dir.alloc = 0;
1848        dir.nr = 0;
1849        dir.permille = options->dirstat_permille;
1850        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1851
1852        changed = 0;
1853        for (i = 0; i < q->nr; i++) {
1854                struct diff_filepair *p = q->queue[i];
1855                const char *name;
1856                unsigned long copied, added, damage;
1857                int content_changed;
1858
1859                name = p->two->path ? p->two->path : p->one->path;
1860
1861                if (p->one->sha1_valid && p->two->sha1_valid)
1862                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1863                else
1864                        content_changed = 1;
1865
1866                if (!content_changed) {
1867                        /*
1868                         * The SHA1 has not changed, so pre-/post-content is
1869                         * identical. We can therefore skip looking at the
1870                         * file contents altogether.
1871                         */
1872                        damage = 0;
1873                        goto found_damage;
1874                }
1875
1876                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1877                        /*
1878                         * In --dirstat-by-file mode, we don't really need to
1879                         * look at the actual file contents at all.
1880                         * The fact that the SHA1 changed is enough for us to
1881                         * add this file to the list of results
1882                         * (with each file contributing equal damage).
1883                         */
1884                        damage = 1;
1885                        goto found_damage;
1886                }
1887
1888                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1889                        diff_populate_filespec(p->one, 0);
1890                        diff_populate_filespec(p->two, 0);
1891                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1892                                               &copied, &added);
1893                        diff_free_filespec_data(p->one);
1894                        diff_free_filespec_data(p->two);
1895                } else if (DIFF_FILE_VALID(p->one)) {
1896                        diff_populate_filespec(p->one, 1);
1897                        copied = added = 0;
1898                        diff_free_filespec_data(p->one);
1899                } else if (DIFF_FILE_VALID(p->two)) {
1900                        diff_populate_filespec(p->two, 1);
1901                        copied = 0;
1902                        added = p->two->size;
1903                        diff_free_filespec_data(p->two);
1904                } else
1905                        continue;
1906
1907                /*
1908                 * Original minus copied is the removed material,
1909                 * added is the new material.  They are both damages
1910                 * made to the preimage.
1911                 * If the resulting damage is zero, we know that
1912                 * diffcore_count_changes() considers the two entries to
1913                 * be identical, but since content_changed is true, we
1914                 * know that there must have been _some_ kind of change,
1915                 * so we force all entries to have damage > 0.
1916                 */
1917                damage = (p->one->size - copied) + added;
1918                if (!damage)
1919                        damage = 1;
1920
1921found_damage:
1922                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1923                dir.files[dir.nr].name = name;
1924                dir.files[dir.nr].changed = damage;
1925                changed += damage;
1926                dir.nr++;
1927        }
1928
1929        /* This can happen even with many files, if everything was renames */
1930        if (!changed)
1931                return;
1932
1933        /* Show all directories with more than x% of the changes */
1934        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1935        gather_dirstat(options, &dir, changed, "", 0);
1936}
1937
1938static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1939{
1940        int i;
1941        unsigned long changed;
1942        struct dirstat_dir dir;
1943
1944        if (data->nr == 0)
1945                return;
1946
1947        dir.files = NULL;
1948        dir.alloc = 0;
1949        dir.nr = 0;
1950        dir.permille = options->dirstat_permille;
1951        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1952
1953        changed = 0;
1954        for (i = 0; i < data->nr; i++) {
1955                struct diffstat_file *file = data->files[i];
1956                unsigned long damage = file->added + file->deleted;
1957                if (file->is_binary)
1958                        /*
1959                         * binary files counts bytes, not lines. Must find some
1960                         * way to normalize binary bytes vs. textual lines.
1961                         * The following heuristic assumes that there are 64
1962                         * bytes per "line".
1963                         * This is stupid and ugly, but very cheap...
1964                         */
1965                        damage = (damage + 63) / 64;
1966                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1967                dir.files[dir.nr].name = file->name;
1968                dir.files[dir.nr].changed = damage;
1969                changed += damage;
1970                dir.nr++;
1971        }
1972
1973        /* This can happen even with many files, if everything was renames */
1974        if (!changed)
1975                return;
1976
1977        /* Show all directories with more than x% of the changes */
1978        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1979        gather_dirstat(options, &dir, changed, "", 0);
1980}
1981
1982static void free_diffstat_info(struct diffstat_t *diffstat)
1983{
1984        int i;
1985        for (i = 0; i < diffstat->nr; i++) {
1986                struct diffstat_file *f = diffstat->files[i];
1987                if (f->name != f->print_name)
1988                        free(f->print_name);
1989                free(f->name);
1990                free(f->from_name);
1991                free(f);
1992        }
1993        free(diffstat->files);
1994}
1995
1996struct checkdiff_t {
1997        const char *filename;
1998        int lineno;
1999        int conflict_marker_size;
2000        struct diff_options *o;
2001        unsigned ws_rule;
2002        unsigned status;
2003};
2004
2005static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2006{
2007        char firstchar;
2008        int cnt;
2009
2010        if (len < marker_size + 1)
2011                return 0;
2012        firstchar = line[0];
2013        switch (firstchar) {
2014        case '=': case '>': case '<': case '|':
2015                break;
2016        default:
2017                return 0;
2018        }
2019        for (cnt = 1; cnt < marker_size; cnt++)
2020                if (line[cnt] != firstchar)
2021                        return 0;
2022        /* line[1] thru line[marker_size-1] are same as firstchar */
2023        if (len < marker_size + 1 || !isspace(line[marker_size]))
2024                return 0;
2025        return 1;
2026}
2027
2028static void checkdiff_consume(void *priv, char *line, unsigned long len)
2029{
2030        struct checkdiff_t *data = priv;
2031        int marker_size = data->conflict_marker_size;
2032        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2033        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2034        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2035        char *err;
2036        char *line_prefix = "";
2037        struct strbuf *msgbuf;
2038
2039        assert(data->o);
2040        if (data->o->output_prefix) {
2041                msgbuf = data->o->output_prefix(data->o,
2042                        data->o->output_prefix_data);
2043                line_prefix = msgbuf->buf;
2044        }
2045
2046        if (line[0] == '+') {
2047                unsigned bad;
2048                data->lineno++;
2049                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2050                        data->status |= 1;
2051                        fprintf(data->o->file,
2052                                "%s%s:%d: leftover conflict marker\n",
2053                                line_prefix, data->filename, data->lineno);
2054                }
2055                bad = ws_check(line + 1, len - 1, data->ws_rule);
2056                if (!bad)
2057                        return;
2058                data->status |= bad;
2059                err = whitespace_error_string(bad);
2060                fprintf(data->o->file, "%s%s:%d: %s.\n",
2061                        line_prefix, data->filename, data->lineno, err);
2062                free(err);
2063                emit_line(data->o, set, reset, line, 1);
2064                ws_check_emit(line + 1, len - 1, data->ws_rule,
2065                              data->o->file, set, reset, ws);
2066        } else if (line[0] == ' ') {
2067                data->lineno++;
2068        } else if (line[0] == '@') {
2069                char *plus = strchr(line, '+');
2070                if (plus)
2071                        data->lineno = strtol(plus, NULL, 10) - 1;
2072                else
2073                        die("invalid diff");
2074        }
2075}
2076
2077static unsigned char *deflate_it(char *data,
2078                                 unsigned long size,
2079                                 unsigned long *result_size)
2080{
2081        int bound;
2082        unsigned char *deflated;
2083        git_zstream stream;
2084
2085        memset(&stream, 0, sizeof(stream));
2086        git_deflate_init(&stream, zlib_compression_level);
2087        bound = git_deflate_bound(&stream, size);
2088        deflated = xmalloc(bound);
2089        stream.next_out = deflated;
2090        stream.avail_out = bound;
2091
2092        stream.next_in = (unsigned char *)data;
2093        stream.avail_in = size;
2094        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2095                ; /* nothing */
2096        git_deflate_end(&stream);
2097        *result_size = stream.total_out;
2098        return deflated;
2099}
2100
2101static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2102{
2103        void *cp;
2104        void *delta;
2105        void *deflated;
2106        void *data;
2107        unsigned long orig_size;
2108        unsigned long delta_size;
2109        unsigned long deflate_size;
2110        unsigned long data_size;
2111
2112        /* We could do deflated delta, or we could do just deflated two,
2113         * whichever is smaller.
2114         */
2115        delta = NULL;
2116        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2117        if (one->size && two->size) {
2118                delta = diff_delta(one->ptr, one->size,
2119                                   two->ptr, two->size,
2120                                   &delta_size, deflate_size);
2121                if (delta) {
2122                        void *to_free = delta;
2123                        orig_size = delta_size;
2124                        delta = deflate_it(delta, delta_size, &delta_size);
2125                        free(to_free);
2126                }
2127        }
2128
2129        if (delta && delta_size < deflate_size) {
2130                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2131                free(deflated);
2132                data = delta;
2133                data_size = delta_size;
2134        }
2135        else {
2136                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2137                free(delta);
2138                data = deflated;
2139                data_size = deflate_size;
2140        }
2141
2142        /* emit data encoded in base85 */
2143        cp = data;
2144        while (data_size) {
2145                int bytes = (52 < data_size) ? 52 : data_size;
2146                char line[70];
2147                data_size -= bytes;
2148                if (bytes <= 26)
2149                        line[0] = bytes + 'A' - 1;
2150                else
2151                        line[0] = bytes - 26 + 'a' - 1;
2152                encode_85(line + 1, cp, bytes);
2153                cp = (char *) cp + bytes;
2154                fprintf(file, "%s", prefix);
2155                fputs(line, file);
2156                fputc('\n', file);
2157        }
2158        fprintf(file, "%s\n", prefix);
2159        free(data);
2160}
2161
2162static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2163{
2164        fprintf(file, "%sGIT binary patch\n", prefix);
2165        emit_binary_diff_body(file, one, two, prefix);
2166        emit_binary_diff_body(file, two, one, prefix);
2167}
2168
2169int diff_filespec_is_binary(struct diff_filespec *one)
2170{
2171        if (one->is_binary == -1) {
2172                diff_filespec_load_driver(one);
2173                if (one->driver->binary != -1)
2174                        one->is_binary = one->driver->binary;
2175                else {
2176                        if (!one->data && DIFF_FILE_VALID(one))
2177                                diff_populate_filespec(one, 0);
2178                        if (one->data)
2179                                one->is_binary = buffer_is_binary(one->data,
2180                                                one->size);
2181                        if (one->is_binary == -1)
2182                                one->is_binary = 0;
2183                }
2184        }
2185        return one->is_binary;
2186}
2187
2188static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2189{
2190        diff_filespec_load_driver(one);
2191        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2192}
2193
2194void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2195{
2196        if (!options->a_prefix)
2197                options->a_prefix = a;
2198        if (!options->b_prefix)
2199                options->b_prefix = b;
2200}
2201
2202struct userdiff_driver *get_textconv(struct diff_filespec *one)
2203{
2204        if (!DIFF_FILE_VALID(one))
2205                return NULL;
2206
2207        diff_filespec_load_driver(one);
2208        return userdiff_get_textconv(one->driver);
2209}
2210
2211static void builtin_diff(const char *name_a,
2212                         const char *name_b,
2213                         struct diff_filespec *one,
2214                         struct diff_filespec *two,
2215                         const char *xfrm_msg,
2216                         int must_show_header,
2217                         struct diff_options *o,
2218                         int complete_rewrite)
2219{
2220        mmfile_t mf1, mf2;
2221        const char *lbl[2];
2222        char *a_one, *b_two;
2223        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2224        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2225        const char *a_prefix, *b_prefix;
2226        struct userdiff_driver *textconv_one = NULL;
2227        struct userdiff_driver *textconv_two = NULL;
2228        struct strbuf header = STRBUF_INIT;
2229        struct strbuf *msgbuf;
2230        char *line_prefix = "";
2231
2232        if (o->output_prefix) {
2233                msgbuf = o->output_prefix(o, o->output_prefix_data);
2234                line_prefix = msgbuf->buf;
2235        }
2236
2237        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2238                        (!one->mode || S_ISGITLINK(one->mode)) &&
2239                        (!two->mode || S_ISGITLINK(two->mode))) {
2240                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2241                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2242                show_submodule_summary(o->file, one ? one->path : two->path,
2243                                one->sha1, two->sha1, two->dirty_submodule,
2244                                del, add, reset);
2245                return;
2246        }
2247
2248        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2249                textconv_one = get_textconv(one);
2250                textconv_two = get_textconv(two);
2251        }
2252
2253        diff_set_mnemonic_prefix(o, "a/", "b/");
2254        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2255                a_prefix = o->b_prefix;
2256                b_prefix = o->a_prefix;
2257        } else {
2258                a_prefix = o->a_prefix;
2259                b_prefix = o->b_prefix;
2260        }
2261
2262        /* Never use a non-valid filename anywhere if at all possible */
2263        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2264        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2265
2266        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2267        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2268        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2269        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2270        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2271        if (lbl[0][0] == '/') {
2272                /* /dev/null */
2273                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2274                if (xfrm_msg)
2275                        strbuf_addstr(&header, xfrm_msg);
2276                must_show_header = 1;
2277        }
2278        else if (lbl[1][0] == '/') {
2279                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2280                if (xfrm_msg)
2281                        strbuf_addstr(&header, xfrm_msg);
2282                must_show_header = 1;
2283        }
2284        else {
2285                if (one->mode != two->mode) {
2286                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2287                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2288                        must_show_header = 1;
2289                }
2290                if (xfrm_msg)
2291                        strbuf_addstr(&header, xfrm_msg);
2292
2293                /*
2294                 * we do not run diff between different kind
2295                 * of objects.
2296                 */
2297                if ((one->mode ^ two->mode) & S_IFMT)
2298                        goto free_ab_and_return;
2299                if (complete_rewrite &&
2300                    (textconv_one || !diff_filespec_is_binary(one)) &&
2301                    (textconv_two || !diff_filespec_is_binary(two))) {
2302                        fprintf(o->file, "%s", header.buf);
2303                        strbuf_reset(&header);
2304                        emit_rewrite_diff(name_a, name_b, one, two,
2305                                                textconv_one, textconv_two, o);
2306                        o->found_changes = 1;
2307                        goto free_ab_and_return;
2308                }
2309        }
2310
2311        if (o->irreversible_delete && lbl[1][0] == '/') {
2312                fprintf(o->file, "%s", header.buf);
2313                strbuf_reset(&header);
2314                goto free_ab_and_return;
2315        } else if (!DIFF_OPT_TST(o, TEXT) &&
2316            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2317              (!textconv_two && diff_filespec_is_binary(two)) )) {
2318                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2319                        die("unable to read files to diff");
2320                /* Quite common confusing case */
2321                if (mf1.size == mf2.size &&
2322                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2323                        if (must_show_header)
2324                                fprintf(o->file, "%s", header.buf);
2325                        goto free_ab_and_return;
2326                }
2327                fprintf(o->file, "%s", header.buf);
2328                strbuf_reset(&header);
2329                if (DIFF_OPT_TST(o, BINARY))
2330                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2331                else
2332                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2333                                line_prefix, lbl[0], lbl[1]);
2334                o->found_changes = 1;
2335        } else {
2336                /* Crazy xdl interfaces.. */
2337                const char *diffopts = getenv("GIT_DIFF_OPTS");
2338                xpparam_t xpp;
2339                xdemitconf_t xecfg;
2340                struct emit_callback ecbdata;
2341                const struct userdiff_funcname *pe;
2342
2343                if (must_show_header) {
2344                        fprintf(o->file, "%s", header.buf);
2345                        strbuf_reset(&header);
2346                }
2347
2348                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2349                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2350
2351                pe = diff_funcname_pattern(one);
2352                if (!pe)
2353                        pe = diff_funcname_pattern(two);
2354
2355                memset(&xpp, 0, sizeof(xpp));
2356                memset(&xecfg, 0, sizeof(xecfg));
2357                memset(&ecbdata, 0, sizeof(ecbdata));
2358                ecbdata.label_path = lbl;
2359                ecbdata.color_diff = want_color(o->use_color);
2360                ecbdata.found_changesp = &o->found_changes;
2361                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2362                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2363                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2364                ecbdata.opt = o;
2365                ecbdata.header = header.len ? &header : NULL;
2366                xpp.flags = o->xdl_opts;
2367                xecfg.ctxlen = o->context;
2368                xecfg.interhunkctxlen = o->interhunkcontext;
2369                xecfg.flags = XDL_EMIT_FUNCNAMES;
2370                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2371                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2372                if (pe)
2373                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2374                if (!diffopts)
2375                        ;
2376                else if (!prefixcmp(diffopts, "--unified="))
2377                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2378                else if (!prefixcmp(diffopts, "-u"))
2379                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2380                if (o->word_diff)
2381                        init_diff_words_data(&ecbdata, o, one, two);
2382                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2383                              &xpp, &xecfg);
2384                if (o->word_diff)
2385                        free_diff_words_data(&ecbdata);
2386                if (textconv_one)
2387                        free(mf1.ptr);
2388                if (textconv_two)
2389                        free(mf2.ptr);
2390                xdiff_clear_find_func(&xecfg);
2391        }
2392
2393 free_ab_and_return:
2394        strbuf_release(&header);
2395        diff_free_filespec_data(one);
2396        diff_free_filespec_data(two);
2397        free(a_one);
2398        free(b_two);
2399        return;
2400}
2401
2402static void builtin_diffstat(const char *name_a, const char *name_b,
2403                             struct diff_filespec *one,
2404                             struct diff_filespec *two,
2405                             struct diffstat_t *diffstat,
2406                             struct diff_options *o,
2407                             int complete_rewrite)
2408{
2409        mmfile_t mf1, mf2;
2410        struct diffstat_file *data;
2411        int same_contents;
2412
2413        data = diffstat_add(diffstat, name_a, name_b);
2414
2415        if (!one || !two) {
2416                data->is_unmerged = 1;
2417                return;
2418        }
2419
2420        same_contents = !hashcmp(one->sha1, two->sha1);
2421
2422        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2423                data->is_binary = 1;
2424                if (same_contents) {
2425                        data->added = 0;
2426                        data->deleted = 0;
2427                } else {
2428                        data->added = diff_filespec_size(two);
2429                        data->deleted = diff_filespec_size(one);
2430                }
2431        }
2432
2433        else if (complete_rewrite) {
2434                diff_populate_filespec(one, 0);
2435                diff_populate_filespec(two, 0);
2436                data->deleted = count_lines(one->data, one->size);
2437                data->added = count_lines(two->data, two->size);
2438        }
2439
2440        else if (!same_contents) {
2441                /* Crazy xdl interfaces.. */
2442                xpparam_t xpp;
2443                xdemitconf_t xecfg;
2444
2445                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2446                        die("unable to read files to diff");
2447
2448                memset(&xpp, 0, sizeof(xpp));
2449                memset(&xecfg, 0, sizeof(xecfg));
2450                xpp.flags = o->xdl_opts;
2451                xecfg.ctxlen = o->context;
2452                xecfg.interhunkctxlen = o->interhunkcontext;
2453                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2454                              &xpp, &xecfg);
2455        }
2456
2457        diff_free_filespec_data(one);
2458        diff_free_filespec_data(two);
2459}
2460
2461static void builtin_checkdiff(const char *name_a, const char *name_b,
2462                              const char *attr_path,
2463                              struct diff_filespec *one,
2464                              struct diff_filespec *two,
2465                              struct diff_options *o)
2466{
2467        mmfile_t mf1, mf2;
2468        struct checkdiff_t data;
2469
2470        if (!two)
2471                return;
2472
2473        memset(&data, 0, sizeof(data));
2474        data.filename = name_b ? name_b : name_a;
2475        data.lineno = 0;
2476        data.o = o;
2477        data.ws_rule = whitespace_rule(attr_path);
2478        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2479
2480        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2481                die("unable to read files to diff");
2482
2483        /*
2484         * All the other codepaths check both sides, but not checking
2485         * the "old" side here is deliberate.  We are checking the newly
2486         * introduced changes, and as long as the "new" side is text, we
2487         * can and should check what it introduces.
2488         */
2489        if (diff_filespec_is_binary(two))
2490                goto free_and_return;
2491        else {
2492                /* Crazy xdl interfaces.. */
2493                xpparam_t xpp;
2494                xdemitconf_t xecfg;
2495
2496                memset(&xpp, 0, sizeof(xpp));
2497                memset(&xecfg, 0, sizeof(xecfg));
2498                xecfg.ctxlen = 1; /* at least one context line */
2499                xpp.flags = 0;
2500                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2501                              &xpp, &xecfg);
2502
2503                if (data.ws_rule & WS_BLANK_AT_EOF) {
2504                        struct emit_callback ecbdata;
2505                        int blank_at_eof;
2506
2507                        ecbdata.ws_rule = data.ws_rule;
2508                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2509                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2510
2511                        if (blank_at_eof) {
2512                                static char *err;
2513                                if (!err)
2514                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2515                                fprintf(o->file, "%s:%d: %s.\n",
2516                                        data.filename, blank_at_eof, err);
2517                                data.status = 1; /* report errors */
2518                        }
2519                }
2520        }
2521 free_and_return:
2522        diff_free_filespec_data(one);
2523        diff_free_filespec_data(two);
2524        if (data.status)
2525                DIFF_OPT_SET(o, CHECK_FAILED);
2526}
2527
2528struct diff_filespec *alloc_filespec(const char *path)
2529{
2530        int namelen = strlen(path);
2531        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2532
2533        memset(spec, 0, sizeof(*spec));
2534        spec->path = (char *)(spec + 1);
2535        memcpy(spec->path, path, namelen+1);
2536        spec->count = 1;
2537        spec->is_binary = -1;
2538        return spec;
2539}
2540
2541void free_filespec(struct diff_filespec *spec)
2542{
2543        if (!--spec->count) {
2544                diff_free_filespec_data(spec);
2545                free(spec);
2546        }
2547}
2548
2549void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2550                   int sha1_valid, unsigned short mode)
2551{
2552        if (mode) {
2553                spec->mode = canon_mode(mode);
2554                hashcpy(spec->sha1, sha1);
2555                spec->sha1_valid = sha1_valid;
2556        }
2557}
2558
2559/*
2560 * Given a name and sha1 pair, if the index tells us the file in
2561 * the work tree has that object contents, return true, so that
2562 * prepare_temp_file() does not have to inflate and extract.
2563 */
2564static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2565{
2566        struct cache_entry *ce;
2567        struct stat st;
2568        int pos, len;
2569
2570        /*
2571         * We do not read the cache ourselves here, because the
2572         * benchmark with my previous version that always reads cache
2573         * shows that it makes things worse for diff-tree comparing
2574         * two linux-2.6 kernel trees in an already checked out work
2575         * tree.  This is because most diff-tree comparisons deal with
2576         * only a small number of files, while reading the cache is
2577         * expensive for a large project, and its cost outweighs the
2578         * savings we get by not inflating the object to a temporary
2579         * file.  Practically, this code only helps when we are used
2580         * by diff-cache --cached, which does read the cache before
2581         * calling us.
2582         */
2583        if (!active_cache)
2584                return 0;
2585
2586        /* We want to avoid the working directory if our caller
2587         * doesn't need the data in a normal file, this system
2588         * is rather slow with its stat/open/mmap/close syscalls,
2589         * and the object is contained in a pack file.  The pack
2590         * is probably already open and will be faster to obtain
2591         * the data through than the working directory.  Loose
2592         * objects however would tend to be slower as they need
2593         * to be individually opened and inflated.
2594         */
2595        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2596                return 0;
2597
2598        len = strlen(name);
2599        pos = cache_name_pos(name, len);
2600        if (pos < 0)
2601                return 0;
2602        ce = active_cache[pos];
2603
2604        /*
2605         * This is not the sha1 we are looking for, or
2606         * unreusable because it is not a regular file.
2607         */
2608        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2609                return 0;
2610
2611        /*
2612         * If ce is marked as "assume unchanged", there is no
2613         * guarantee that work tree matches what we are looking for.
2614         */
2615        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2616                return 0;
2617
2618        /*
2619         * If ce matches the file in the work tree, we can reuse it.
2620         */
2621        if (ce_uptodate(ce) ||
2622            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2623                return 1;
2624
2625        return 0;
2626}
2627
2628static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2629{
2630        int len;
2631        char *data = xmalloc(100), *dirty = "";
2632
2633        /* Are we looking at the work tree? */
2634        if (s->dirty_submodule)
2635                dirty = "-dirty";
2636
2637        len = snprintf(data, 100,
2638                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2639        s->data = data;
2640        s->size = len;
2641        s->should_free = 1;
2642        if (size_only) {
2643                s->data = NULL;
2644                free(data);
2645        }
2646        return 0;
2647}
2648
2649/*
2650 * While doing rename detection and pickaxe operation, we may need to
2651 * grab the data for the blob (or file) for our own in-core comparison.
2652 * diff_filespec has data and size fields for this purpose.
2653 */
2654int diff_populate_filespec(struct diff_filespec *s, int size_only)
2655{
2656        int err = 0;
2657        if (!DIFF_FILE_VALID(s))
2658                die("internal error: asking to populate invalid file.");
2659        if (S_ISDIR(s->mode))
2660                return -1;
2661
2662        if (s->data)
2663                return 0;
2664
2665        if (size_only && 0 < s->size)
2666                return 0;
2667
2668        if (S_ISGITLINK(s->mode))
2669                return diff_populate_gitlink(s, size_only);
2670
2671        if (!s->sha1_valid ||
2672            reuse_worktree_file(s->path, s->sha1, 0)) {
2673                struct strbuf buf = STRBUF_INIT;
2674                struct stat st;
2675                int fd;
2676
2677                if (lstat(s->path, &st) < 0) {
2678                        if (errno == ENOENT) {
2679                        err_empty:
2680                                err = -1;
2681                        empty:
2682                                s->data = (char *)"";
2683                                s->size = 0;
2684                                return err;
2685                        }
2686                }
2687                s->size = xsize_t(st.st_size);
2688                if (!s->size)
2689                        goto empty;
2690                if (S_ISLNK(st.st_mode)) {
2691                        struct strbuf sb = STRBUF_INIT;
2692
2693                        if (strbuf_readlink(&sb, s->path, s->size))
2694                                goto err_empty;
2695                        s->size = sb.len;
2696                        s->data = strbuf_detach(&sb, NULL);
2697                        s->should_free = 1;
2698                        return 0;
2699                }
2700                if (size_only)
2701                        return 0;
2702                fd = open(s->path, O_RDONLY);
2703                if (fd < 0)
2704                        goto err_empty;
2705                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2706                close(fd);
2707                s->should_munmap = 1;
2708
2709                /*
2710                 * Convert from working tree format to canonical git format
2711                 */
2712                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2713                        size_t size = 0;
2714                        munmap(s->data, s->size);
2715                        s->should_munmap = 0;
2716                        s->data = strbuf_detach(&buf, &size);
2717                        s->size = size;
2718                        s->should_free = 1;
2719                }
2720        }
2721        else {
2722                enum object_type type;
2723                if (size_only) {
2724                        type = sha1_object_info(s->sha1, &s->size);
2725                        if (type < 0)
2726                                die("unable to read %s", sha1_to_hex(s->sha1));
2727                } else {
2728                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2729                        if (!s->data)
2730                                die("unable to read %s", sha1_to_hex(s->sha1));
2731                        s->should_free = 1;
2732                }
2733        }
2734        return 0;
2735}
2736
2737void diff_free_filespec_blob(struct diff_filespec *s)
2738{
2739        if (s->should_free)
2740                free(s->data);
2741        else if (s->should_munmap)
2742                munmap(s->data, s->size);
2743
2744        if (s->should_free || s->should_munmap) {
2745                s->should_free = s->should_munmap = 0;
2746                s->data = NULL;
2747        }
2748}
2749
2750void diff_free_filespec_data(struct diff_filespec *s)
2751{
2752        diff_free_filespec_blob(s);
2753        free(s->cnt_data);
2754        s->cnt_data = NULL;
2755}
2756
2757static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2758                           void *blob,
2759                           unsigned long size,
2760                           const unsigned char *sha1,
2761                           int mode)
2762{
2763        int fd;
2764        struct strbuf buf = STRBUF_INIT;
2765        struct strbuf template = STRBUF_INIT;
2766        char *path_dup = xstrdup(path);
2767        const char *base = basename(path_dup);
2768
2769        /* Generate "XXXXXX_basename.ext" */
2770        strbuf_addstr(&template, "XXXXXX_");
2771        strbuf_addstr(&template, base);
2772
2773        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2774                        strlen(base) + 1);
2775        if (fd < 0)
2776                die_errno("unable to create temp-file");
2777        if (convert_to_working_tree(path,
2778                        (const char *)blob, (size_t)size, &buf)) {
2779                blob = buf.buf;
2780                size = buf.len;
2781        }
2782        if (write_in_full(fd, blob, size) != size)
2783                die_errno("unable to write temp-file");
2784        close(fd);
2785        temp->name = temp->tmp_path;
2786        strcpy(temp->hex, sha1_to_hex(sha1));
2787        temp->hex[40] = 0;
2788        sprintf(temp->mode, "%06o", mode);
2789        strbuf_release(&buf);
2790        strbuf_release(&template);
2791        free(path_dup);
2792}
2793
2794static struct diff_tempfile *prepare_temp_file(const char *name,
2795                struct diff_filespec *one)
2796{
2797        struct diff_tempfile *temp = claim_diff_tempfile();
2798
2799        if (!DIFF_FILE_VALID(one)) {
2800        not_a_valid_file:
2801                /* A '-' entry produces this for file-2, and
2802                 * a '+' entry produces this for file-1.
2803                 */
2804                temp->name = "/dev/null";
2805                strcpy(temp->hex, ".");
2806                strcpy(temp->mode, ".");
2807                return temp;
2808        }
2809
2810        if (!remove_tempfile_installed) {
2811                atexit(remove_tempfile);
2812                sigchain_push_common(remove_tempfile_on_signal);
2813                remove_tempfile_installed = 1;
2814        }
2815
2816        if (!one->sha1_valid ||
2817            reuse_worktree_file(name, one->sha1, 1)) {
2818                struct stat st;
2819                if (lstat(name, &st) < 0) {
2820                        if (errno == ENOENT)
2821                                goto not_a_valid_file;
2822                        die_errno("stat(%s)", name);
2823                }
2824                if (S_ISLNK(st.st_mode)) {
2825                        struct strbuf sb = STRBUF_INIT;
2826                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2827                                die_errno("readlink(%s)", name);
2828                        prep_temp_blob(name, temp, sb.buf, sb.len,
2829                                       (one->sha1_valid ?
2830                                        one->sha1 : null_sha1),
2831                                       (one->sha1_valid ?
2832                                        one->mode : S_IFLNK));
2833                        strbuf_release(&sb);
2834                }
2835                else {
2836                        /* we can borrow from the file in the work tree */
2837                        temp->name = name;
2838                        if (!one->sha1_valid)
2839                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2840                        else
2841                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2842                        /* Even though we may sometimes borrow the
2843                         * contents from the work tree, we always want
2844                         * one->mode.  mode is trustworthy even when
2845                         * !(one->sha1_valid), as long as
2846                         * DIFF_FILE_VALID(one).
2847                         */
2848                        sprintf(temp->mode, "%06o", one->mode);
2849                }
2850                return temp;
2851        }
2852        else {
2853                if (diff_populate_filespec(one, 0))
2854                        die("cannot read data blob for %s", one->path);
2855                prep_temp_blob(name, temp, one->data, one->size,
2856                               one->sha1, one->mode);
2857        }
2858        return temp;
2859}
2860
2861/* An external diff command takes:
2862 *
2863 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2864 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2865 *
2866 */
2867static void run_external_diff(const char *pgm,
2868                              const char *name,
2869                              const char *other,
2870                              struct diff_filespec *one,
2871                              struct diff_filespec *two,
2872                              const char *xfrm_msg,
2873                              int complete_rewrite)
2874{
2875        const char *spawn_arg[10];
2876        int retval;
2877        const char **arg = &spawn_arg[0];
2878
2879        if (one && two) {
2880                struct diff_tempfile *temp_one, *temp_two;
2881                const char *othername = (other ? other : name);
2882                temp_one = prepare_temp_file(name, one);
2883                temp_two = prepare_temp_file(othername, two);
2884                *arg++ = pgm;
2885                *arg++ = name;
2886                *arg++ = temp_one->name;
2887                *arg++ = temp_one->hex;
2888                *arg++ = temp_one->mode;
2889                *arg++ = temp_two->name;
2890                *arg++ = temp_two->hex;
2891                *arg++ = temp_two->mode;
2892                if (other) {
2893                        *arg++ = other;
2894                        *arg++ = xfrm_msg;
2895                }
2896        } else {
2897                *arg++ = pgm;
2898                *arg++ = name;
2899        }
2900        *arg = NULL;
2901        fflush(NULL);
2902        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2903        remove_tempfile();
2904        if (retval) {
2905                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2906                exit(1);
2907        }
2908}
2909
2910static int similarity_index(struct diff_filepair *p)
2911{
2912        return p->score * 100 / MAX_SCORE;
2913}
2914
2915static void fill_metainfo(struct strbuf *msg,
2916                          const char *name,
2917                          const char *other,
2918                          struct diff_filespec *one,
2919                          struct diff_filespec *two,
2920                          struct diff_options *o,
2921                          struct diff_filepair *p,
2922                          int *must_show_header,
2923                          int use_color)
2924{
2925        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2926        const char *reset = diff_get_color(use_color, DIFF_RESET);
2927        struct strbuf *msgbuf;
2928        char *line_prefix = "";
2929
2930        *must_show_header = 1;
2931        if (o->output_prefix) {
2932                msgbuf = o->output_prefix(o, o->output_prefix_data);
2933                line_prefix = msgbuf->buf;
2934        }
2935        strbuf_init(msg, PATH_MAX * 2 + 300);
2936        switch (p->status) {
2937        case DIFF_STATUS_COPIED:
2938                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2939                            line_prefix, set, similarity_index(p));
2940                strbuf_addf(msg, "%s\n%s%scopy from ",
2941                            reset,  line_prefix, set);
2942                quote_c_style(name, msg, NULL, 0);
2943                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2944                quote_c_style(other, msg, NULL, 0);
2945                strbuf_addf(msg, "%s\n", reset);
2946                break;
2947        case DIFF_STATUS_RENAMED:
2948                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2949                            line_prefix, set, similarity_index(p));
2950                strbuf_addf(msg, "%s\n%s%srename from ",
2951                            reset, line_prefix, set);
2952                quote_c_style(name, msg, NULL, 0);
2953                strbuf_addf(msg, "%s\n%s%srename to ",
2954                            reset, line_prefix, set);
2955                quote_c_style(other, msg, NULL, 0);
2956                strbuf_addf(msg, "%s\n", reset);
2957                break;
2958        case DIFF_STATUS_MODIFIED:
2959                if (p->score) {
2960                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2961                                    line_prefix,
2962                                    set, similarity_index(p), reset);
2963                        break;
2964                }
2965                /* fallthru */
2966        default:
2967                *must_show_header = 0;
2968        }
2969        if (one && two && hashcmp(one->sha1, two->sha1)) {
2970                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2971
2972                if (DIFF_OPT_TST(o, BINARY)) {
2973                        mmfile_t mf;
2974                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2975                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2976                                abbrev = 40;
2977                }
2978                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2979                            find_unique_abbrev(one->sha1, abbrev));
2980                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2981                if (one->mode == two->mode)
2982                        strbuf_addf(msg, " %06o", one->mode);
2983                strbuf_addf(msg, "%s\n", reset);
2984        }
2985}
2986
2987static void run_diff_cmd(const char *pgm,
2988                         const char *name,
2989                         const char *other,
2990                         const char *attr_path,
2991                         struct diff_filespec *one,
2992                         struct diff_filespec *two,
2993                         struct strbuf *msg,
2994                         struct diff_options *o,
2995                         struct diff_filepair *p)
2996{
2997        const char *xfrm_msg = NULL;
2998        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2999        int must_show_header = 0;
3000
3001
3002        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3003                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3004                if (drv && drv->external)
3005                        pgm = drv->external;
3006        }
3007
3008        if (msg) {
3009                /*
3010                 * don't use colors when the header is intended for an
3011                 * external diff driver
3012                 */
3013                fill_metainfo(msg, name, other, one, two, o, p,
3014                              &must_show_header,
3015                              want_color(o->use_color) && !pgm);
3016                xfrm_msg = msg->len ? msg->buf : NULL;
3017        }
3018
3019        if (pgm) {
3020                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3021                                  complete_rewrite);
3022                return;
3023        }
3024        if (one && two)
3025                builtin_diff(name, other ? other : name,
3026                             one, two, xfrm_msg, must_show_header,
3027                             o, complete_rewrite);
3028        else
3029                fprintf(o->file, "* Unmerged path %s\n", name);
3030}
3031
3032static void diff_fill_sha1_info(struct diff_filespec *one)
3033{
3034        if (DIFF_FILE_VALID(one)) {
3035                if (!one->sha1_valid) {
3036                        struct stat st;
3037                        if (one->is_stdin) {
3038                                hashcpy(one->sha1, null_sha1);
3039                                return;
3040                        }
3041                        if (lstat(one->path, &st) < 0)
3042                                die_errno("stat '%s'", one->path);
3043                        if (index_path(one->sha1, one->path, &st, 0))
3044                                die("cannot hash %s", one->path);
3045                }
3046        }
3047        else
3048                hashclr(one->sha1);
3049}
3050
3051static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3052{
3053        /* Strip the prefix but do not molest /dev/null and absolute paths */
3054        if (*namep && **namep != '/') {
3055                *namep += prefix_length;
3056                if (**namep == '/')
3057                        ++*namep;
3058        }
3059        if (*otherp && **otherp != '/') {
3060                *otherp += prefix_length;
3061                if (**otherp == '/')
3062                        ++*otherp;
3063        }
3064}
3065
3066static void run_diff(struct diff_filepair *p, struct diff_options *o)
3067{
3068        const char *pgm = external_diff();
3069        struct strbuf msg;
3070        struct diff_filespec *one = p->one;
3071        struct diff_filespec *two = p->two;
3072        const char *name;
3073        const char *other;
3074        const char *attr_path;
3075
3076        name  = p->one->path;
3077        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3078        attr_path = name;
3079        if (o->prefix_length)
3080                strip_prefix(o->prefix_length, &name, &other);
3081
3082        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3083                pgm = NULL;
3084
3085        if (DIFF_PAIR_UNMERGED(p)) {
3086                run_diff_cmd(pgm, name, NULL, attr_path,
3087                             NULL, NULL, NULL, o, p);
3088                return;
3089        }
3090
3091        diff_fill_sha1_info(one);
3092        diff_fill_sha1_info(two);
3093
3094        if (!pgm &&
3095            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3096            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3097                /*
3098                 * a filepair that changes between file and symlink
3099                 * needs to be split into deletion and creation.
3100                 */
3101                struct diff_filespec *null = alloc_filespec(two->path);
3102                run_diff_cmd(NULL, name, other, attr_path,
3103                             one, null, &msg, o, p);
3104                free(null);
3105                strbuf_release(&msg);
3106
3107                null = alloc_filespec(one->path);
3108                run_diff_cmd(NULL, name, other, attr_path,
3109                             null, two, &msg, o, p);
3110                free(null);
3111        }
3112        else
3113                run_diff_cmd(pgm, name, other, attr_path,
3114                             one, two, &msg, o, p);
3115
3116        strbuf_release(&msg);
3117}
3118
3119static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3120                         struct diffstat_t *diffstat)
3121{
3122        const char *name;
3123        const char *other;
3124        int complete_rewrite = 0;
3125
3126        if (DIFF_PAIR_UNMERGED(p)) {
3127                /* unmerged */
3128                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3129                return;
3130        }
3131
3132        name = p->one->path;
3133        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3134
3135        if (o->prefix_length)
3136                strip_prefix(o->prefix_length, &name, &other);
3137
3138        diff_fill_sha1_info(p->one);
3139        diff_fill_sha1_info(p->two);
3140
3141        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3142                complete_rewrite = 1;
3143        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3144}
3145
3146static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3147{
3148        const char *name;
3149        const char *other;
3150        const char *attr_path;
3151
3152        if (DIFF_PAIR_UNMERGED(p)) {
3153                /* unmerged */
3154                return;
3155        }
3156
3157        name = p->one->path;
3158        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3159        attr_path = other ? other : name;
3160
3161        if (o->prefix_length)
3162                strip_prefix(o->prefix_length, &name, &other);
3163
3164        diff_fill_sha1_info(p->one);
3165        diff_fill_sha1_info(p->two);
3166
3167        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3168}
3169
3170void diff_setup(struct diff_options *options)
3171{
3172        memcpy(options, &default_diff_options, sizeof(*options));
3173
3174        options->file = stdout;
3175
3176        options->line_termination = '\n';
3177        options->break_opt = -1;
3178        options->rename_limit = -1;
3179        options->dirstat_permille = diff_dirstat_permille_default;
3180        options->context = diff_context_default;
3181        DIFF_OPT_SET(options, RENAME_EMPTY);
3182
3183        options->change = diff_change;
3184        options->add_remove = diff_addremove;
3185        options->use_color = diff_use_color_default;
3186        options->detect_rename = diff_detect_rename_default;
3187
3188        if (diff_no_prefix) {
3189                options->a_prefix = options->b_prefix = "";
3190        } else if (!diff_mnemonic_prefix) {
3191                options->a_prefix = "a/";
3192                options->b_prefix = "b/";
3193        }
3194}
3195
3196void diff_setup_done(struct diff_options *options)
3197{
3198        int count = 0;
3199
3200        if (options->output_format & DIFF_FORMAT_NAME)
3201                count++;
3202        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3203                count++;
3204        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3205                count++;
3206        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3207                count++;
3208        if (count > 1)
3209                die("--name-only, --name-status, --check and -s are mutually exclusive");
3210
3211        /*
3212         * Most of the time we can say "there are changes"
3213         * only by checking if there are changed paths, but
3214         * --ignore-whitespace* options force us to look
3215         * inside contents.
3216         */
3217
3218        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3219            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3220            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3221                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3222        else
3223                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3224
3225        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3226                options->detect_rename = DIFF_DETECT_COPY;
3227
3228        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3229                options->prefix = NULL;
3230        if (options->prefix)
3231                options->prefix_length = strlen(options->prefix);
3232        else
3233                options->prefix_length = 0;
3234
3235        if (options->output_format & (DIFF_FORMAT_NAME |
3236                                      DIFF_FORMAT_NAME_STATUS |
3237                                      DIFF_FORMAT_CHECKDIFF |
3238                                      DIFF_FORMAT_NO_OUTPUT))
3239                options->output_format &= ~(DIFF_FORMAT_RAW |
3240                                            DIFF_FORMAT_NUMSTAT |
3241                                            DIFF_FORMAT_DIFFSTAT |
3242                                            DIFF_FORMAT_SHORTSTAT |
3243                                            DIFF_FORMAT_DIRSTAT |
3244                                            DIFF_FORMAT_SUMMARY |
3245                                            DIFF_FORMAT_PATCH);
3246
3247        /*
3248         * These cases always need recursive; we do not drop caller-supplied
3249         * recursive bits for other formats here.
3250         */
3251        if (options->output_format & (DIFF_FORMAT_PATCH |
3252                                      DIFF_FORMAT_NUMSTAT |
3253                                      DIFF_FORMAT_DIFFSTAT |
3254                                      DIFF_FORMAT_SHORTSTAT |
3255                                      DIFF_FORMAT_DIRSTAT |
3256                                      DIFF_FORMAT_SUMMARY |
3257                                      DIFF_FORMAT_CHECKDIFF))
3258                DIFF_OPT_SET(options, RECURSIVE);
3259        /*
3260         * Also pickaxe would not work very well if you do not say recursive
3261         */
3262        if (options->pickaxe)
3263                DIFF_OPT_SET(options, RECURSIVE);
3264        /*
3265         * When patches are generated, submodules diffed against the work tree
3266         * must be checked for dirtiness too so it can be shown in the output
3267         */
3268        if (options->output_format & DIFF_FORMAT_PATCH)
3269                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3270
3271        if (options->detect_rename && options->rename_limit < 0)
3272                options->rename_limit = diff_rename_limit_default;
3273        if (options->setup & DIFF_SETUP_USE_CACHE) {
3274                if (!active_cache)
3275                        /* read-cache does not die even when it fails
3276                         * so it is safe for us to do this here.  Also
3277                         * it does not smudge active_cache or active_nr
3278                         * when it fails, so we do not have to worry about
3279                         * cleaning it up ourselves either.
3280                         */
3281                        read_cache();
3282        }
3283        if (options->abbrev <= 0 || 40 < options->abbrev)
3284                options->abbrev = 40; /* full */
3285
3286        /*
3287         * It does not make sense to show the first hit we happened
3288         * to have found.  It does not make sense not to return with
3289         * exit code in such a case either.
3290         */
3291        if (DIFF_OPT_TST(options, QUICK)) {
3292                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3293                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3294        }
3295}
3296
3297static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3298{
3299        char c, *eq;
3300        int len;
3301
3302        if (*arg != '-')
3303                return 0;
3304        c = *++arg;
3305        if (!c)
3306                return 0;
3307        if (c == arg_short) {
3308                c = *++arg;
3309                if (!c)
3310                        return 1;
3311                if (val && isdigit(c)) {
3312                        char *end;
3313                        int n = strtoul(arg, &end, 10);
3314                        if (*end)
3315                                return 0;
3316                        *val = n;
3317                        return 1;
3318                }
3319                return 0;
3320        }
3321        if (c != '-')
3322                return 0;
3323        arg++;
3324        eq = strchr(arg, '=');
3325        if (eq)
3326                len = eq - arg;
3327        else
3328                len = strlen(arg);
3329        if (!len || strncmp(arg, arg_long, len))
3330                return 0;
3331        if (eq) {
3332                int n;
3333                char *end;
3334                if (!isdigit(*++eq))
3335                        return 0;
3336                n = strtoul(eq, &end, 10);
3337                if (*end)
3338                        return 0;
3339                *val = n;
3340        }
3341        return 1;
3342}
3343
3344static int diff_scoreopt_parse(const char *opt);
3345
3346static inline int short_opt(char opt, const char **argv,
3347                            const char **optarg)
3348{
3349        const char *arg = argv[0];
3350        if (arg[0] != '-' || arg[1] != opt)
3351                return 0;
3352        if (arg[2] != '\0') {
3353                *optarg = arg + 2;
3354                return 1;
3355        }
3356        if (!argv[1])
3357                die("Option '%c' requires a value", opt);
3358        *optarg = argv[1];
3359        return 2;
3360}
3361
3362int parse_long_opt(const char *opt, const char **argv,
3363                   const char **optarg)
3364{
3365        const char *arg = argv[0];
3366        if (arg[0] != '-' || arg[1] != '-')
3367                return 0;
3368        arg += strlen("--");
3369        if (prefixcmp(arg, opt))
3370                return 0;
3371        arg += strlen(opt);
3372        if (*arg == '=') { /* sticked form: --option=value */
3373                *optarg = arg + 1;
3374                return 1;
3375        }
3376        if (*arg != '\0')
3377                return 0;
3378        /* separate form: --option value */
3379        if (!argv[1])
3380                die("Option '--%s' requires a value", opt);
3381        *optarg = argv[1];
3382        return 2;
3383}
3384
3385static int stat_opt(struct diff_options *options, const char **av)
3386{
3387        const char *arg = av[0];
3388        char *end;
3389        int width = options->stat_width;
3390        int name_width = options->stat_name_width;
3391        int graph_width = options->stat_graph_width;
3392        int count = options->stat_count;
3393        int argcount = 1;
3394
3395        arg += strlen("--stat");
3396        end = (char *)arg;
3397
3398        switch (*arg) {
3399        case '-':
3400                if (!prefixcmp(arg, "-width")) {
3401                        arg += strlen("-width");
3402                        if (*arg == '=')
3403                                width = strtoul(arg + 1, &end, 10);
3404                        else if (!*arg && !av[1])
3405                                die("Option '--stat-width' requires a value");
3406                        else if (!*arg) {
3407                                width = strtoul(av[1], &end, 10);
3408                                argcount = 2;
3409                        }
3410                } else if (!prefixcmp(arg, "-name-width")) {
3411                        arg += strlen("-name-width");
3412                        if (*arg == '=')
3413                                name_width = strtoul(arg + 1, &end, 10);
3414                        else if (!*arg && !av[1])
3415                                die("Option '--stat-name-width' requires a value");
3416                        else if (!*arg) {
3417                                name_width = strtoul(av[1], &end, 10);
3418                                argcount = 2;
3419                        }
3420                } else if (!prefixcmp(arg, "-graph-width")) {
3421                        arg += strlen("-graph-width");
3422                        if (*arg == '=')
3423                                graph_width = strtoul(arg + 1, &end, 10);
3424                        else if (!*arg && !av[1])
3425                                die("Option '--stat-graph-width' requires a value");
3426                        else if (!*arg) {
3427                                graph_width = strtoul(av[1], &end, 10);
3428                                argcount = 2;
3429                        }
3430                } else if (!prefixcmp(arg, "-count")) {
3431                        arg += strlen("-count");
3432                        if (*arg == '=')
3433                                count = strtoul(arg + 1, &end, 10);
3434                        else if (!*arg && !av[1])
3435                                die("Option '--stat-count' requires a value");
3436                        else if (!*arg) {
3437                                count = strtoul(av[1], &end, 10);
3438                                argcount = 2;
3439                        }
3440                }
3441                break;
3442        case '=':
3443                width = strtoul(arg+1, &end, 10);
3444                if (*end == ',')
3445                        name_width = strtoul(end+1, &end, 10);
3446                if (*end == ',')
3447                        count = strtoul(end+1, &end, 10);
3448        }
3449
3450        /* Important! This checks all the error cases! */
3451        if (*end)
3452                return 0;
3453        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3454        options->stat_name_width = name_width;
3455        options->stat_graph_width = graph_width;
3456        options->stat_width = width;
3457        options->stat_count = count;
3458        return argcount;
3459}
3460
3461static int parse_dirstat_opt(struct diff_options *options, const char *params)
3462{
3463        struct strbuf errmsg = STRBUF_INIT;
3464        if (parse_dirstat_params(options, params, &errmsg))
3465                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3466                    errmsg.buf);
3467        strbuf_release(&errmsg);
3468        /*
3469         * The caller knows a dirstat-related option is given from the command
3470         * line; allow it to say "return this_function();"
3471         */
3472        options->output_format |= DIFF_FORMAT_DIRSTAT;
3473        return 1;
3474}
3475
3476int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3477{
3478        const char *arg = av[0];
3479        const char *optarg;
3480        int argcount;
3481
3482        /* Output format options */
3483        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3484                options->output_format |= DIFF_FORMAT_PATCH;
3485        else if (opt_arg(arg, 'U', "unified", &options->context))
3486                options->output_format |= DIFF_FORMAT_PATCH;
3487        else if (!strcmp(arg, "--raw"))
3488                options->output_format |= DIFF_FORMAT_RAW;
3489        else if (!strcmp(arg, "--patch-with-raw"))
3490                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3491        else if (!strcmp(arg, "--numstat"))
3492                options->output_format |= DIFF_FORMAT_NUMSTAT;
3493        else if (!strcmp(arg, "--shortstat"))
3494                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3495        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3496                return parse_dirstat_opt(options, "");
3497        else if (!prefixcmp(arg, "-X"))
3498                return parse_dirstat_opt(options, arg + 2);
3499        else if (!prefixcmp(arg, "--dirstat="))
3500                return parse_dirstat_opt(options, arg + 10);
3501        else if (!strcmp(arg, "--cumulative"))
3502                return parse_dirstat_opt(options, "cumulative");
3503        else if (!strcmp(arg, "--dirstat-by-file"))
3504                return parse_dirstat_opt(options, "files");
3505        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3506                parse_dirstat_opt(options, "files");
3507                return parse_dirstat_opt(options, arg + 18);
3508        }
3509        else if (!strcmp(arg, "--check"))
3510                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3511        else if (!strcmp(arg, "--summary"))
3512                options->output_format |= DIFF_FORMAT_SUMMARY;
3513        else if (!strcmp(arg, "--patch-with-stat"))
3514                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3515        else if (!strcmp(arg, "--name-only"))
3516                options->output_format |= DIFF_FORMAT_NAME;
3517        else if (!strcmp(arg, "--name-status"))
3518                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3519        else if (!strcmp(arg, "-s"))
3520                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3521        else if (!prefixcmp(arg, "--stat"))
3522                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3523                return stat_opt(options, av);
3524
3525        /* renames options */
3526        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3527                 !strcmp(arg, "--break-rewrites")) {
3528                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3529                        return error("invalid argument to -B: %s", arg+2);
3530        }
3531        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3532                 !strcmp(arg, "--find-renames")) {
3533                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3534                        return error("invalid argument to -M: %s", arg+2);
3535                options->detect_rename = DIFF_DETECT_RENAME;
3536        }
3537        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3538                options->irreversible_delete = 1;
3539        }
3540        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3541                 !strcmp(arg, "--find-copies")) {
3542                if (options->detect_rename == DIFF_DETECT_COPY)
3543                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3544                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3545                        return error("invalid argument to -C: %s", arg+2);
3546                options->detect_rename = DIFF_DETECT_COPY;
3547        }
3548        else if (!strcmp(arg, "--no-renames"))
3549                options->detect_rename = 0;
3550        else if (!strcmp(arg, "--rename-empty"))
3551                DIFF_OPT_SET(options, RENAME_EMPTY);
3552        else if (!strcmp(arg, "--no-rename-empty"))
3553                DIFF_OPT_CLR(options, RENAME_EMPTY);
3554        else if (!strcmp(arg, "--relative"))
3555                DIFF_OPT_SET(options, RELATIVE_NAME);
3556        else if (!prefixcmp(arg, "--relative=")) {
3557                DIFF_OPT_SET(options, RELATIVE_NAME);
3558                options->prefix = arg + 11;
3559        }
3560
3561        /* xdiff options */
3562        else if (!strcmp(arg, "--minimal"))
3563                DIFF_XDL_SET(options, NEED_MINIMAL);
3564        else if (!strcmp(arg, "--no-minimal"))
3565                DIFF_XDL_CLR(options, NEED_MINIMAL);
3566        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3567                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3568        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3569                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3570        else if (!strcmp(arg, "--ignore-space-at-eol"))
3571                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3572        else if (!strcmp(arg, "--patience"))
3573                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3574        else if (!strcmp(arg, "--histogram"))
3575                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3576
3577        /* flags options */
3578        else if (!strcmp(arg, "--binary")) {
3579                options->output_format |= DIFF_FORMAT_PATCH;
3580                DIFF_OPT_SET(options, BINARY);
3581        }
3582        else if (!strcmp(arg, "--full-index"))
3583                DIFF_OPT_SET(options, FULL_INDEX);
3584        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3585                DIFF_OPT_SET(options, TEXT);
3586        else if (!strcmp(arg, "-R"))
3587                DIFF_OPT_SET(options, REVERSE_DIFF);
3588        else if (!strcmp(arg, "--find-copies-harder"))
3589                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3590        else if (!strcmp(arg, "--follow"))
3591                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3592        else if (!strcmp(arg, "--color"))
3593                options->use_color = 1;
3594        else if (!prefixcmp(arg, "--color=")) {
3595                int value = git_config_colorbool(NULL, arg+8);
3596                if (value < 0)
3597                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3598                options->use_color = value;
3599        }
3600        else if (!strcmp(arg, "--no-color"))
3601                options->use_color = 0;
3602        else if (!strcmp(arg, "--color-words")) {
3603                options->use_color = 1;
3604                options->word_diff = DIFF_WORDS_COLOR;
3605        }
3606        else if (!prefixcmp(arg, "--color-words=")) {
3607                options->use_color = 1;
3608                options->word_diff = DIFF_WORDS_COLOR;
3609                options->word_regex = arg + 14;
3610        }
3611        else if (!strcmp(arg, "--word-diff")) {
3612                if (options->word_diff == DIFF_WORDS_NONE)
3613                        options->word_diff = DIFF_WORDS_PLAIN;
3614        }
3615        else if (!prefixcmp(arg, "--word-diff=")) {
3616                const char *type = arg + 12;
3617                if (!strcmp(type, "plain"))
3618                        options->word_diff = DIFF_WORDS_PLAIN;
3619                else if (!strcmp(type, "color")) {
3620                        options->use_color = 1;
3621                        options->word_diff = DIFF_WORDS_COLOR;
3622                }
3623                else if (!strcmp(type, "porcelain"))
3624                        options->word_diff = DIFF_WORDS_PORCELAIN;
3625                else if (!strcmp(type, "none"))
3626                        options->word_diff = DIFF_WORDS_NONE;
3627                else
3628                        die("bad --word-diff argument: %s", type);
3629        }
3630        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3631                if (options->word_diff == DIFF_WORDS_NONE)
3632                        options->word_diff = DIFF_WORDS_PLAIN;
3633                options->word_regex = optarg;
3634                return argcount;
3635        }
3636        else if (!strcmp(arg, "--exit-code"))
3637                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3638        else if (!strcmp(arg, "--quiet"))
3639                DIFF_OPT_SET(options, QUICK);
3640        else if (!strcmp(arg, "--ext-diff"))
3641                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3642        else if (!strcmp(arg, "--no-ext-diff"))
3643                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3644        else if (!strcmp(arg, "--textconv"))
3645                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3646        else if (!strcmp(arg, "--no-textconv"))
3647                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3648        else if (!strcmp(arg, "--ignore-submodules")) {
3649                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3650                handle_ignore_submodules_arg(options, "all");
3651        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3652                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3653                handle_ignore_submodules_arg(options, arg + 20);
3654        } else if (!strcmp(arg, "--submodule"))
3655                DIFF_OPT_SET(options, SUBMODULE_LOG);
3656        else if (!prefixcmp(arg, "--submodule=")) {
3657                if (!strcmp(arg + 12, "log"))
3658                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3659        }
3660
3661        /* misc options */
3662        else if (!strcmp(arg, "-z"))
3663                options->line_termination = 0;
3664        else if ((argcount = short_opt('l', av, &optarg))) {
3665                options->rename_limit = strtoul(optarg, NULL, 10);
3666                return argcount;
3667        }
3668        else if ((argcount = short_opt('S', av, &optarg))) {
3669                options->pickaxe = optarg;
3670                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3671                return argcount;
3672        } else if ((argcount = short_opt('G', av, &optarg))) {
3673                options->pickaxe = optarg;
3674                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3675                return argcount;
3676        }
3677        else if (!strcmp(arg, "--pickaxe-all"))
3678                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3679        else if (!strcmp(arg, "--pickaxe-regex"))
3680                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3681        else if ((argcount = short_opt('O', av, &optarg))) {
3682                options->orderfile = optarg;
3683                return argcount;
3684        }
3685        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3686                options->filter = optarg;
3687                return argcount;
3688        }
3689        else if (!strcmp(arg, "--abbrev"))
3690                options->abbrev = DEFAULT_ABBREV;
3691        else if (!prefixcmp(arg, "--abbrev=")) {
3692                options->abbrev = strtoul(arg + 9, NULL, 10);
3693                if (options->abbrev < MINIMUM_ABBREV)
3694                        options->abbrev = MINIMUM_ABBREV;
3695                else if (40 < options->abbrev)
3696                        options->abbrev = 40;
3697        }
3698        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3699                options->a_prefix = optarg;
3700                return argcount;
3701        }
3702        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3703                options->b_prefix = optarg;
3704                return argcount;
3705        }
3706        else if (!strcmp(arg, "--no-prefix"))
3707                options->a_prefix = options->b_prefix = "";
3708        else if (opt_arg(arg, '\0', "inter-hunk-context",
3709                         &options->interhunkcontext))
3710                ;
3711        else if (!strcmp(arg, "-W"))
3712                DIFF_OPT_SET(options, FUNCCONTEXT);
3713        else if (!strcmp(arg, "--function-context"))
3714                DIFF_OPT_SET(options, FUNCCONTEXT);
3715        else if (!strcmp(arg, "--no-function-context"))
3716                DIFF_OPT_CLR(options, FUNCCONTEXT);
3717        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3718                options->file = fopen(optarg, "w");
3719                if (!options->file)
3720                        die_errno("Could not open '%s'", optarg);
3721                options->close_file = 1;
3722                return argcount;
3723        } else
3724                return 0;
3725        return 1;
3726}
3727
3728int parse_rename_score(const char **cp_p)
3729{
3730        unsigned long num, scale;
3731        int ch, dot;
3732        const char *cp = *cp_p;
3733
3734        num = 0;
3735        scale = 1;
3736        dot = 0;
3737        for (;;) {
3738                ch = *cp;
3739                if ( !dot && ch == '.' ) {
3740                        scale = 1;
3741                        dot = 1;
3742                } else if ( ch == '%' ) {
3743                        scale = dot ? scale*100 : 100;
3744                        cp++;   /* % is always at the end */
3745                        break;
3746                } else if ( ch >= '0' && ch <= '9' ) {
3747                        if ( scale < 100000 ) {
3748                                scale *= 10;
3749                                num = (num*10) + (ch-'0');
3750                        }
3751                } else {
3752                        break;
3753                }
3754                cp++;
3755        }
3756        *cp_p = cp;
3757
3758        /* user says num divided by scale and we say internally that
3759         * is MAX_SCORE * num / scale.
3760         */
3761        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3762}
3763
3764static int diff_scoreopt_parse(const char *opt)
3765{
3766        int opt1, opt2, cmd;
3767
3768        if (*opt++ != '-')
3769                return -1;
3770        cmd = *opt++;
3771        if (cmd == '-') {
3772                /* convert the long-form arguments into short-form versions */
3773                if (!prefixcmp(opt, "break-rewrites")) {
3774                        opt += strlen("break-rewrites");
3775                        if (*opt == 0 || *opt++ == '=')
3776                                cmd = 'B';
3777                } else if (!prefixcmp(opt, "find-copies")) {
3778                        opt += strlen("find-copies");
3779                        if (*opt == 0 || *opt++ == '=')
3780                                cmd = 'C';
3781                } else if (!prefixcmp(opt, "find-renames")) {
3782                        opt += strlen("find-renames");
3783                        if (*opt == 0 || *opt++ == '=')
3784                                cmd = 'M';
3785                }
3786        }
3787        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3788                return -1; /* that is not a -M, -C nor -B option */
3789
3790        opt1 = parse_rename_score(&opt);
3791        if (cmd != 'B')
3792                opt2 = 0;
3793        else {
3794                if (*opt == 0)
3795                        opt2 = 0;
3796                else if (*opt != '/')
3797                        return -1; /* we expect -B80/99 or -B80 */
3798                else {
3799                        opt++;
3800                        opt2 = parse_rename_score(&opt);
3801                }
3802        }
3803        if (*opt != 0)
3804                return -1;
3805        return opt1 | (opt2 << 16);
3806}
3807
3808struct diff_queue_struct diff_queued_diff;
3809
3810void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3811{
3812        if (queue->alloc <= queue->nr) {
3813                queue->alloc = alloc_nr(queue->alloc);
3814                queue->queue = xrealloc(queue->queue,
3815                                        sizeof(dp) * queue->alloc);
3816        }
3817        queue->queue[queue->nr++] = dp;
3818}
3819
3820struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3821                                 struct diff_filespec *one,
3822                                 struct diff_filespec *two)
3823{
3824        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3825        dp->one = one;
3826        dp->two = two;
3827        if (queue)
3828                diff_q(queue, dp);
3829        return dp;
3830}
3831
3832void diff_free_filepair(struct diff_filepair *p)
3833{
3834        free_filespec(p->one);
3835        free_filespec(p->two);
3836        free(p);
3837}
3838
3839/* This is different from find_unique_abbrev() in that
3840 * it stuffs the result with dots for alignment.
3841 */
3842const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3843{
3844        int abblen;
3845        const char *abbrev;
3846        if (len == 40)
3847                return sha1_to_hex(sha1);
3848
3849        abbrev = find_unique_abbrev(sha1, len);
3850        abblen = strlen(abbrev);
3851        if (abblen < 37) {
3852                static char hex[41];
3853                if (len < abblen && abblen <= len + 2)
3854                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3855                else
3856                        sprintf(hex, "%s...", abbrev);
3857                return hex;
3858        }
3859        return sha1_to_hex(sha1);
3860}
3861
3862static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3863{
3864        int line_termination = opt->line_termination;
3865        int inter_name_termination = line_termination ? '\t' : '\0';
3866        if (opt->output_prefix) {
3867                struct strbuf *msg = NULL;
3868                msg = opt->output_prefix(opt, opt->output_prefix_data);
3869                fprintf(opt->file, "%s", msg->buf);
3870        }
3871
3872        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3873                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3874                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3875                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3876        }
3877        if (p->score) {
3878                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3879                        inter_name_termination);
3880        } else {
3881                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3882        }
3883
3884        if (p->status == DIFF_STATUS_COPIED ||
3885            p->status == DIFF_STATUS_RENAMED) {
3886                const char *name_a, *name_b;
3887                name_a = p->one->path;
3888                name_b = p->two->path;
3889                strip_prefix(opt->prefix_length, &name_a, &name_b);
3890                write_name_quoted(name_a, opt->file, inter_name_termination);
3891                write_name_quoted(name_b, opt->file, line_termination);
3892        } else {
3893                const char *name_a, *name_b;
3894                name_a = p->one->mode ? p->one->path : p->two->path;
3895                name_b = NULL;
3896                strip_prefix(opt->prefix_length, &name_a, &name_b);
3897                write_name_quoted(name_a, opt->file, line_termination);
3898        }
3899}
3900
3901int diff_unmodified_pair(struct diff_filepair *p)
3902{
3903        /* This function is written stricter than necessary to support
3904         * the currently implemented transformers, but the idea is to
3905         * let transformers to produce diff_filepairs any way they want,
3906         * and filter and clean them up here before producing the output.
3907         */
3908        struct diff_filespec *one = p->one, *two = p->two;
3909
3910        if (DIFF_PAIR_UNMERGED(p))
3911                return 0; /* unmerged is interesting */
3912
3913        /* deletion, addition, mode or type change
3914         * and rename are all interesting.
3915         */
3916        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3917            DIFF_PAIR_MODE_CHANGED(p) ||
3918            strcmp(one->path, two->path))
3919                return 0;
3920
3921        /* both are valid and point at the same path.  that is, we are
3922         * dealing with a change.
3923         */
3924        if (one->sha1_valid && two->sha1_valid &&
3925            !hashcmp(one->sha1, two->sha1) &&
3926            !one->dirty_submodule && !two->dirty_submodule)
3927                return 1; /* no change */
3928        if (!one->sha1_valid && !two->sha1_valid)
3929                return 1; /* both look at the same file on the filesystem. */
3930        return 0;
3931}
3932
3933static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3934{
3935        if (diff_unmodified_pair(p))
3936                return;
3937
3938        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3939            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3940                return; /* no tree diffs in patch format */
3941
3942        run_diff(p, o);
3943}
3944
3945static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3946                            struct diffstat_t *diffstat)
3947{
3948        if (diff_unmodified_pair(p))
3949                return;
3950
3951        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3952            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3953                return; /* no useful stat for tree diffs */
3954
3955        run_diffstat(p, o, diffstat);
3956}
3957
3958static void diff_flush_checkdiff(struct diff_filepair *p,
3959                struct diff_options *o)
3960{
3961        if (diff_unmodified_pair(p))
3962                return;
3963
3964        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3965            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3966                return; /* nothing to check in tree diffs */
3967
3968        run_checkdiff(p, o);
3969}
3970
3971int diff_queue_is_empty(void)
3972{
3973        struct diff_queue_struct *q = &diff_queued_diff;
3974        int i;
3975        for (i = 0; i < q->nr; i++)
3976                if (!diff_unmodified_pair(q->queue[i]))
3977                        return 0;
3978        return 1;
3979}
3980
3981#if DIFF_DEBUG
3982void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3983{
3984        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3985                x, one ? one : "",
3986                s->path,
3987                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3988                s->mode,
3989                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3990        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3991                x, one ? one : "",
3992                s->size, s->xfrm_flags);
3993}
3994
3995void diff_debug_filepair(const struct diff_filepair *p, int i)
3996{
3997        diff_debug_filespec(p->one, i, "one");
3998        diff_debug_filespec(p->two, i, "two");
3999        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4000                p->score, p->status ? p->status : '?',
4001                p->one->rename_used, p->broken_pair);
4002}
4003
4004void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4005{
4006        int i;
4007        if (msg)
4008                fprintf(stderr, "%s\n", msg);
4009        fprintf(stderr, "q->nr = %d\n", q->nr);
4010        for (i = 0; i < q->nr; i++) {
4011                struct diff_filepair *p = q->queue[i];
4012                diff_debug_filepair(p, i);
4013        }
4014}
4015#endif
4016
4017static void diff_resolve_rename_copy(void)
4018{
4019        int i;
4020        struct diff_filepair *p;
4021        struct diff_queue_struct *q = &diff_queued_diff;
4022
4023        diff_debug_queue("resolve-rename-copy", q);
4024
4025        for (i = 0; i < q->nr; i++) {
4026                p = q->queue[i];
4027                p->status = 0; /* undecided */
4028                if (DIFF_PAIR_UNMERGED(p))
4029                        p->status = DIFF_STATUS_UNMERGED;
4030                else if (!DIFF_FILE_VALID(p->one))
4031                        p->status = DIFF_STATUS_ADDED;
4032                else if (!DIFF_FILE_VALID(p->two))
4033                        p->status = DIFF_STATUS_DELETED;
4034                else if (DIFF_PAIR_TYPE_CHANGED(p))
4035                        p->status = DIFF_STATUS_TYPE_CHANGED;
4036
4037                /* from this point on, we are dealing with a pair
4038                 * whose both sides are valid and of the same type, i.e.
4039                 * either in-place edit or rename/copy edit.
4040                 */
4041                else if (DIFF_PAIR_RENAME(p)) {
4042                        /*
4043                         * A rename might have re-connected a broken
4044                         * pair up, causing the pathnames to be the
4045                         * same again. If so, that's not a rename at
4046                         * all, just a modification..
4047                         *
4048                         * Otherwise, see if this source was used for
4049                         * multiple renames, in which case we decrement
4050                         * the count, and call it a copy.
4051                         */
4052                        if (!strcmp(p->one->path, p->two->path))
4053                                p->status = DIFF_STATUS_MODIFIED;
4054                        else if (--p->one->rename_used > 0)
4055                                p->status = DIFF_STATUS_COPIED;
4056                        else
4057                                p->status = DIFF_STATUS_RENAMED;
4058                }
4059                else if (hashcmp(p->one->sha1, p->two->sha1) ||
4060                         p->one->mode != p->two->mode ||
4061                         p->one->dirty_submodule ||
4062                         p->two->dirty_submodule ||
4063                         is_null_sha1(p->one->sha1))
4064                        p->status = DIFF_STATUS_MODIFIED;
4065                else {
4066                        /* This is a "no-change" entry and should not
4067                         * happen anymore, but prepare for broken callers.
4068                         */
4069                        error("feeding unmodified %s to diffcore",
4070                              p->one->path);
4071                        p->status = DIFF_STATUS_UNKNOWN;
4072                }
4073        }
4074        diff_debug_queue("resolve-rename-copy done", q);
4075}
4076
4077static int check_pair_status(struct diff_filepair *p)
4078{
4079        switch (p->status) {
4080        case DIFF_STATUS_UNKNOWN:
4081                return 0;
4082        case 0:
4083                die("internal error in diff-resolve-rename-copy");
4084        default:
4085                return 1;
4086        }
4087}
4088
4089static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4090{
4091        int fmt = opt->output_format;
4092
4093        if (fmt & DIFF_FORMAT_CHECKDIFF)
4094                diff_flush_checkdiff(p, opt);
4095        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4096                diff_flush_raw(p, opt);
4097        else if (fmt & DIFF_FORMAT_NAME) {
4098                const char *name_a, *name_b;
4099                name_a = p->two->path;
4100                name_b = NULL;
4101                strip_prefix(opt->prefix_length, &name_a, &name_b);
4102                write_name_quoted(name_a, opt->file, opt->line_termination);
4103        }
4104}
4105
4106static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4107{
4108        if (fs->mode)
4109                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4110        else
4111                fprintf(file, " %s ", newdelete);
4112        write_name_quoted(fs->path, file, '\n');
4113}
4114
4115
4116static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4117                const char *line_prefix)
4118{
4119        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4120                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4121                        p->two->mode, show_name ? ' ' : '\n');
4122                if (show_name) {
4123                        write_name_quoted(p->two->path, file, '\n');
4124                }
4125        }
4126}
4127
4128static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4129                        const char *line_prefix)
4130{
4131        char *names = pprint_rename(p->one->path, p->two->path);
4132
4133        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4134        free(names);
4135        show_mode_change(file, p, 0, line_prefix);
4136}
4137
4138static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4139{
4140        FILE *file = opt->file;
4141        char *line_prefix = "";
4142
4143        if (opt->output_prefix) {
4144                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4145                line_prefix = buf->buf;
4146        }
4147
4148        switch(p->status) {
4149        case DIFF_STATUS_DELETED:
4150                fputs(line_prefix, file);
4151                show_file_mode_name(file, "delete", p->one);
4152                break;
4153        case DIFF_STATUS_ADDED:
4154                fputs(line_prefix, file);
4155                show_file_mode_name(file, "create", p->two);
4156                break;
4157        case DIFF_STATUS_COPIED:
4158                fputs(line_prefix, file);
4159                show_rename_copy(file, "copy", p, line_prefix);
4160                break;
4161        case DIFF_STATUS_RENAMED:
4162                fputs(line_prefix, file);
4163                show_rename_copy(file, "rename", p, line_prefix);
4164                break;
4165        default:
4166                if (p->score) {
4167                        fprintf(file, "%s rewrite ", line_prefix);
4168                        write_name_quoted(p->two->path, file, ' ');
4169                        fprintf(file, "(%d%%)\n", similarity_index(p));
4170                }
4171                show_mode_change(file, p, !p->score, line_prefix);
4172                break;
4173        }
4174}
4175
4176struct patch_id_t {
4177        git_SHA_CTX *ctx;
4178        int patchlen;
4179};
4180
4181static int remove_space(char *line, int len)
4182{
4183        int i;
4184        char *dst = line;
4185        unsigned char c;
4186
4187        for (i = 0; i < len; i++)
4188                if (!isspace((c = line[i])))
4189                        *dst++ = c;
4190
4191        return dst - line;
4192}
4193
4194static void patch_id_consume(void *priv, char *line, unsigned long len)
4195{
4196        struct patch_id_t *data = priv;
4197        int new_len;
4198
4199        /* Ignore line numbers when computing the SHA1 of the patch */
4200        if (!prefixcmp(line, "@@ -"))
4201                return;
4202
4203        new_len = remove_space(line, len);
4204
4205        git_SHA1_Update(data->ctx, line, new_len);
4206        data->patchlen += new_len;
4207}
4208
4209/* returns 0 upon success, and writes result into sha1 */
4210static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4211{
4212        struct diff_queue_struct *q = &diff_queued_diff;
4213        int i;
4214        git_SHA_CTX ctx;
4215        struct patch_id_t data;
4216        char buffer[PATH_MAX * 4 + 20];
4217
4218        git_SHA1_Init(&ctx);
4219        memset(&data, 0, sizeof(struct patch_id_t));
4220        data.ctx = &ctx;
4221
4222        for (i = 0; i < q->nr; i++) {
4223                xpparam_t xpp;
4224                xdemitconf_t xecfg;
4225                mmfile_t mf1, mf2;
4226                struct diff_filepair *p = q->queue[i];
4227                int len1, len2;
4228
4229                memset(&xpp, 0, sizeof(xpp));
4230                memset(&xecfg, 0, sizeof(xecfg));
4231                if (p->status == 0)
4232                        return error("internal diff status error");
4233                if (p->status == DIFF_STATUS_UNKNOWN)
4234                        continue;
4235                if (diff_unmodified_pair(p))
4236                        continue;
4237                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4238                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4239                        continue;
4240                if (DIFF_PAIR_UNMERGED(p))
4241                        continue;
4242
4243                diff_fill_sha1_info(p->one);
4244                diff_fill_sha1_info(p->two);
4245                if (fill_mmfile(&mf1, p->one) < 0 ||
4246                                fill_mmfile(&mf2, p->two) < 0)
4247                        return error("unable to read files to diff");
4248
4249                len1 = remove_space(p->one->path, strlen(p->one->path));
4250                len2 = remove_space(p->two->path, strlen(p->two->path));
4251                if (p->one->mode == 0)
4252                        len1 = snprintf(buffer, sizeof(buffer),
4253                                        "diff--gita/%.*sb/%.*s"
4254                                        "newfilemode%06o"
4255                                        "---/dev/null"
4256                                        "+++b/%.*s",
4257                                        len1, p->one->path,
4258                                        len2, p->two->path,
4259                                        p->two->mode,
4260                                        len2, p->two->path);
4261                else if (p->two->mode == 0)
4262                        len1 = snprintf(buffer, sizeof(buffer),
4263                                        "diff--gita/%.*sb/%.*s"
4264                                        "deletedfilemode%06o"
4265                                        "---a/%.*s"
4266                                        "+++/dev/null",
4267                                        len1, p->one->path,
4268                                        len2, p->two->path,
4269                                        p->one->mode,
4270                                        len1, p->one->path);
4271                else
4272                        len1 = snprintf(buffer, sizeof(buffer),
4273                                        "diff--gita/%.*sb/%.*s"
4274                                        "---a/%.*s"
4275                                        "+++b/%.*s",
4276                                        len1, p->one->path,
4277                                        len2, p->two->path,
4278                                        len1, p->one->path,
4279                                        len2, p->two->path);
4280                git_SHA1_Update(&ctx, buffer, len1);
4281
4282                if (diff_filespec_is_binary(p->one) ||
4283                    diff_filespec_is_binary(p->two)) {
4284                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4285                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4286                        continue;
4287                }
4288
4289                xpp.flags = 0;
4290                xecfg.ctxlen = 3;
4291                xecfg.flags = 0;
4292                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4293                              &xpp, &xecfg);
4294        }
4295
4296        git_SHA1_Final(sha1, &ctx);
4297        return 0;
4298}
4299
4300int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4301{
4302        struct diff_queue_struct *q = &diff_queued_diff;
4303        int i;
4304        int result = diff_get_patch_id(options, sha1);
4305
4306        for (i = 0; i < q->nr; i++)
4307                diff_free_filepair(q->queue[i]);
4308
4309        free(q->queue);
4310        DIFF_QUEUE_CLEAR(q);
4311
4312        return result;
4313}
4314
4315static int is_summary_empty(const struct diff_queue_struct *q)
4316{
4317        int i;
4318
4319        for (i = 0; i < q->nr; i++) {
4320                const struct diff_filepair *p = q->queue[i];
4321
4322                switch (p->status) {
4323                case DIFF_STATUS_DELETED:
4324                case DIFF_STATUS_ADDED:
4325                case DIFF_STATUS_COPIED:
4326                case DIFF_STATUS_RENAMED:
4327                        return 0;
4328                default:
4329                        if (p->score)
4330                                return 0;
4331                        if (p->one->mode && p->two->mode &&
4332                            p->one->mode != p->two->mode)
4333                                return 0;
4334                        break;
4335                }
4336        }
4337        return 1;
4338}
4339
4340static const char rename_limit_warning[] =
4341"inexact rename detection was skipped due to too many files.";
4342
4343static const char degrade_cc_to_c_warning[] =
4344"only found copies from modified paths due to too many files.";
4345
4346static const char rename_limit_advice[] =
4347"you may want to set your %s variable to at least "
4348"%d and retry the command.";
4349
4350void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4351{
4352        if (degraded_cc)
4353                warning(degrade_cc_to_c_warning);
4354        else if (needed)
4355                warning(rename_limit_warning);
4356        else
4357                return;
4358        if (0 < needed && needed < 32767)
4359                warning(rename_limit_advice, varname, needed);
4360}
4361
4362void diff_flush(struct diff_options *options)
4363{
4364        struct diff_queue_struct *q = &diff_queued_diff;
4365        int i, output_format = options->output_format;
4366        int separator = 0;
4367        int dirstat_by_line = 0;
4368
4369        /*
4370         * Order: raw, stat, summary, patch
4371         * or:    name/name-status/checkdiff (other bits clear)
4372         */
4373        if (!q->nr)
4374                goto free_queue;
4375
4376        if (output_format & (DIFF_FORMAT_RAW |
4377                             DIFF_FORMAT_NAME |
4378                             DIFF_FORMAT_NAME_STATUS |
4379                             DIFF_FORMAT_CHECKDIFF)) {
4380                for (i = 0; i < q->nr; i++) {
4381                        struct diff_filepair *p = q->queue[i];
4382                        if (check_pair_status(p))
4383                                flush_one_pair(p, options);
4384                }
4385                separator++;
4386        }
4387
4388        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4389                dirstat_by_line = 1;
4390
4391        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4392            dirstat_by_line) {
4393                struct diffstat_t diffstat;
4394
4395                memset(&diffstat, 0, sizeof(struct diffstat_t));
4396                for (i = 0; i < q->nr; i++) {
4397                        struct diff_filepair *p = q->queue[i];
4398                        if (check_pair_status(p))
4399                                diff_flush_stat(p, options, &diffstat);
4400                }
4401                if (output_format & DIFF_FORMAT_NUMSTAT)
4402                        show_numstat(&diffstat, options);
4403                if (output_format & DIFF_FORMAT_DIFFSTAT)
4404                        show_stats(&diffstat, options);
4405                if (output_format & DIFF_FORMAT_SHORTSTAT)
4406                        show_shortstats(&diffstat, options);
4407                if (output_format & DIFF_FORMAT_DIRSTAT)
4408                        show_dirstat_by_line(&diffstat, options);
4409                free_diffstat_info(&diffstat);
4410                separator++;
4411        }
4412        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4413                show_dirstat(options);
4414
4415        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4416                for (i = 0; i < q->nr; i++) {
4417                        diff_summary(options, q->queue[i]);
4418                }
4419                separator++;
4420        }
4421
4422        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4423            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4424            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4425                /*
4426                 * run diff_flush_patch for the exit status. setting
4427                 * options->file to /dev/null should be safe, becaue we
4428                 * aren't supposed to produce any output anyway.
4429                 */
4430                if (options->close_file)
4431                        fclose(options->file);
4432                options->file = fopen("/dev/null", "w");
4433                if (!options->file)
4434                        die_errno("Could not open /dev/null");
4435                options->close_file = 1;
4436                for (i = 0; i < q->nr; i++) {
4437                        struct diff_filepair *p = q->queue[i];
4438                        if (check_pair_status(p))
4439                                diff_flush_patch(p, options);
4440                        if (options->found_changes)
4441                                break;
4442                }
4443        }
4444
4445        if (output_format & DIFF_FORMAT_PATCH) {
4446                if (separator) {
4447                        if (options->output_prefix) {
4448                                struct strbuf *msg = NULL;
4449                                msg = options->output_prefix(options,
4450                                        options->output_prefix_data);
4451                                fwrite(msg->buf, msg->len, 1, stdout);
4452                        }
4453                        putc(options->line_termination, options->file);
4454                        if (options->stat_sep) {
4455                                /* attach patch instead of inline */
4456                                fputs(options->stat_sep, options->file);
4457                        }
4458                }
4459
4460                for (i = 0; i < q->nr; i++) {
4461                        struct diff_filepair *p = q->queue[i];
4462                        if (check_pair_status(p))
4463                                diff_flush_patch(p, options);
4464                }
4465        }
4466
4467        if (output_format & DIFF_FORMAT_CALLBACK)
4468                options->format_callback(q, options, options->format_callback_data);
4469
4470        for (i = 0; i < q->nr; i++)
4471                diff_free_filepair(q->queue[i]);
4472free_queue:
4473        free(q->queue);
4474        DIFF_QUEUE_CLEAR(q);
4475        if (options->close_file)
4476                fclose(options->file);
4477
4478        /*
4479         * Report the content-level differences with HAS_CHANGES;
4480         * diff_addremove/diff_change does not set the bit when
4481         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4482         */
4483        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4484                if (options->found_changes)
4485                        DIFF_OPT_SET(options, HAS_CHANGES);
4486                else
4487                        DIFF_OPT_CLR(options, HAS_CHANGES);
4488        }
4489}
4490
4491static void diffcore_apply_filter(const char *filter)
4492{
4493        int i;
4494        struct diff_queue_struct *q = &diff_queued_diff;
4495        struct diff_queue_struct outq;
4496        DIFF_QUEUE_CLEAR(&outq);
4497
4498        if (!filter)
4499                return;
4500
4501        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4502                int found;
4503                for (i = found = 0; !found && i < q->nr; i++) {
4504                        struct diff_filepair *p = q->queue[i];
4505                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4506                             ((p->score &&
4507                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4508                              (!p->score &&
4509                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4510                            ((p->status != DIFF_STATUS_MODIFIED) &&
4511                             strchr(filter, p->status)))
4512                                found++;
4513                }
4514                if (found)
4515                        return;
4516
4517                /* otherwise we will clear the whole queue
4518                 * by copying the empty outq at the end of this
4519                 * function, but first clear the current entries
4520                 * in the queue.
4521                 */
4522                for (i = 0; i < q->nr; i++)
4523                        diff_free_filepair(q->queue[i]);
4524        }
4525        else {
4526                /* Only the matching ones */
4527                for (i = 0; i < q->nr; i++) {
4528                        struct diff_filepair *p = q->queue[i];
4529
4530                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4531                             ((p->score &&
4532                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4533                              (!p->score &&
4534                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4535                            ((p->status != DIFF_STATUS_MODIFIED) &&
4536                             strchr(filter, p->status)))
4537                                diff_q(&outq, p);
4538                        else
4539                                diff_free_filepair(p);
4540                }
4541        }
4542        free(q->queue);
4543        *q = outq;
4544}
4545
4546/* Check whether two filespecs with the same mode and size are identical */
4547static int diff_filespec_is_identical(struct diff_filespec *one,
4548                                      struct diff_filespec *two)
4549{
4550        if (S_ISGITLINK(one->mode))
4551                return 0;
4552        if (diff_populate_filespec(one, 0))
4553                return 0;
4554        if (diff_populate_filespec(two, 0))
4555                return 0;
4556        return !memcmp(one->data, two->data, one->size);
4557}
4558
4559static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4560{
4561        int i;
4562        struct diff_queue_struct *q = &diff_queued_diff;
4563        struct diff_queue_struct outq;
4564        DIFF_QUEUE_CLEAR(&outq);
4565
4566        for (i = 0; i < q->nr; i++) {
4567                struct diff_filepair *p = q->queue[i];
4568
4569                /*
4570                 * 1. Entries that come from stat info dirtiness
4571                 *    always have both sides (iow, not create/delete),
4572                 *    one side of the object name is unknown, with
4573                 *    the same mode and size.  Keep the ones that
4574                 *    do not match these criteria.  They have real
4575                 *    differences.
4576                 *
4577                 * 2. At this point, the file is known to be modified,
4578                 *    with the same mode and size, and the object
4579                 *    name of one side is unknown.  Need to inspect
4580                 *    the identical contents.
4581                 */
4582                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4583                    !DIFF_FILE_VALID(p->two) ||
4584                    (p->one->sha1_valid && p->two->sha1_valid) ||
4585                    (p->one->mode != p->two->mode) ||
4586                    diff_populate_filespec(p->one, 1) ||
4587                    diff_populate_filespec(p->two, 1) ||
4588                    (p->one->size != p->two->size) ||
4589                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4590                        diff_q(&outq, p);
4591                else {
4592                        /*
4593                         * The caller can subtract 1 from skip_stat_unmatch
4594                         * to determine how many paths were dirty only
4595                         * due to stat info mismatch.
4596                         */
4597                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4598                                diffopt->skip_stat_unmatch++;
4599                        diff_free_filepair(p);
4600                }
4601        }
4602        free(q->queue);
4603        *q = outq;
4604}
4605
4606static int diffnamecmp(const void *a_, const void *b_)
4607{
4608        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4609        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4610        const char *name_a, *name_b;
4611
4612        name_a = a->one ? a->one->path : a->two->path;
4613        name_b = b->one ? b->one->path : b->two->path;
4614        return strcmp(name_a, name_b);
4615}
4616
4617void diffcore_fix_diff_index(struct diff_options *options)
4618{
4619        struct diff_queue_struct *q = &diff_queued_diff;
4620        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4621}
4622
4623void diffcore_std(struct diff_options *options)
4624{
4625        if (options->skip_stat_unmatch)
4626                diffcore_skip_stat_unmatch(options);
4627        if (!options->found_follow) {
4628                /* See try_to_follow_renames() in tree-diff.c */
4629                if (options->break_opt != -1)
4630                        diffcore_break(options->break_opt);
4631                if (options->detect_rename)
4632                        diffcore_rename(options);
4633                if (options->break_opt != -1)
4634                        diffcore_merge_broken();
4635        }
4636        if (options->pickaxe)
4637                diffcore_pickaxe(options);
4638        if (options->orderfile)
4639                diffcore_order(options->orderfile);
4640        if (!options->found_follow)
4641                /* See try_to_follow_renames() in tree-diff.c */
4642                diff_resolve_rename_copy();
4643        diffcore_apply_filter(options->filter);
4644
4645        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4646                DIFF_OPT_SET(options, HAS_CHANGES);
4647        else
4648                DIFF_OPT_CLR(options, HAS_CHANGES);
4649
4650        options->found_follow = 0;
4651}
4652
4653int diff_result_code(struct diff_options *opt, int status)
4654{
4655        int result = 0;
4656
4657        diff_warn_rename_limit("diff.renamelimit",
4658                               opt->needed_rename_limit,
4659                               opt->degraded_cc_to_c);
4660        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4661            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4662                return status;
4663        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4664            DIFF_OPT_TST(opt, HAS_CHANGES))
4665                result |= 01;
4666        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4667            DIFF_OPT_TST(opt, CHECK_FAILED))
4668                result |= 02;
4669        return result;
4670}
4671
4672int diff_can_quit_early(struct diff_options *opt)
4673{
4674        return (DIFF_OPT_TST(opt, QUICK) &&
4675                !opt->filter &&
4676                DIFF_OPT_TST(opt, HAS_CHANGES));
4677}
4678
4679/*
4680 * Shall changes to this submodule be ignored?
4681 *
4682 * Submodule changes can be configured to be ignored separately for each path,
4683 * but that configuration can be overridden from the command line.
4684 */
4685static int is_submodule_ignored(const char *path, struct diff_options *options)
4686{
4687        int ignored = 0;
4688        unsigned orig_flags = options->flags;
4689        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4690                set_diffopt_flags_from_submodule_config(options, path);
4691        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4692                ignored = 1;
4693        options->flags = orig_flags;
4694        return ignored;
4695}
4696
4697void diff_addremove(struct diff_options *options,
4698                    int addremove, unsigned mode,
4699                    const unsigned char *sha1,
4700                    int sha1_valid,
4701                    const char *concatpath, unsigned dirty_submodule)
4702{
4703        struct diff_filespec *one, *two;
4704
4705        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4706                return;
4707
4708        /* This may look odd, but it is a preparation for
4709         * feeding "there are unchanged files which should
4710         * not produce diffs, but when you are doing copy
4711         * detection you would need them, so here they are"
4712         * entries to the diff-core.  They will be prefixed
4713         * with something like '=' or '*' (I haven't decided
4714         * which but should not make any difference).
4715         * Feeding the same new and old to diff_change()
4716         * also has the same effect.
4717         * Before the final output happens, they are pruned after
4718         * merged into rename/copy pairs as appropriate.
4719         */
4720        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4721                addremove = (addremove == '+' ? '-' :
4722                             addremove == '-' ? '+' : addremove);
4723
4724        if (options->prefix &&
4725            strncmp(concatpath, options->prefix, options->prefix_length))
4726                return;
4727
4728        one = alloc_filespec(concatpath);
4729        two = alloc_filespec(concatpath);
4730
4731        if (addremove != '+')
4732                fill_filespec(one, sha1, sha1_valid, mode);
4733        if (addremove != '-') {
4734                fill_filespec(two, sha1, sha1_valid, mode);
4735                two->dirty_submodule = dirty_submodule;
4736        }
4737
4738        diff_queue(&diff_queued_diff, one, two);
4739        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4740                DIFF_OPT_SET(options, HAS_CHANGES);
4741}
4742
4743void diff_change(struct diff_options *options,
4744                 unsigned old_mode, unsigned new_mode,
4745                 const unsigned char *old_sha1,
4746                 const unsigned char *new_sha1,
4747                 int old_sha1_valid, int new_sha1_valid,
4748                 const char *concatpath,
4749                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4750{
4751        struct diff_filespec *one, *two;
4752
4753        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4754            is_submodule_ignored(concatpath, options))
4755                return;
4756
4757        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4758                unsigned tmp;
4759                const unsigned char *tmp_c;
4760                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4761                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4762                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
4763                        new_sha1_valid = tmp;
4764                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4765                        new_dirty_submodule = tmp;
4766        }
4767
4768        if (options->prefix &&
4769            strncmp(concatpath, options->prefix, options->prefix_length))
4770                return;
4771
4772        one = alloc_filespec(concatpath);
4773        two = alloc_filespec(concatpath);
4774        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
4775        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
4776        one->dirty_submodule = old_dirty_submodule;
4777        two->dirty_submodule = new_dirty_submodule;
4778
4779        diff_queue(&diff_queued_diff, one, two);
4780        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4781                DIFF_OPT_SET(options, HAS_CHANGES);
4782}
4783
4784struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4785{
4786        struct diff_filepair *pair;
4787        struct diff_filespec *one, *two;
4788
4789        if (options->prefix &&
4790            strncmp(path, options->prefix, options->prefix_length))
4791                return NULL;
4792
4793        one = alloc_filespec(path);
4794        two = alloc_filespec(path);
4795        pair = diff_queue(&diff_queued_diff, one, two);
4796        pair->is_unmerged = 1;
4797        return pair;
4798}
4799
4800static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4801                size_t *outsize)
4802{
4803        struct diff_tempfile *temp;
4804        const char *argv[3];
4805        const char **arg = argv;
4806        struct child_process child;
4807        struct strbuf buf = STRBUF_INIT;
4808        int err = 0;
4809
4810        temp = prepare_temp_file(spec->path, spec);
4811        *arg++ = pgm;
4812        *arg++ = temp->name;
4813        *arg = NULL;
4814
4815        memset(&child, 0, sizeof(child));
4816        child.use_shell = 1;
4817        child.argv = argv;
4818        child.out = -1;
4819        if (start_command(&child)) {
4820                remove_tempfile();
4821                return NULL;
4822        }
4823
4824        if (strbuf_read(&buf, child.out, 0) < 0)
4825                err = error("error reading from textconv command '%s'", pgm);
4826        close(child.out);
4827
4828        if (finish_command(&child) || err) {
4829                strbuf_release(&buf);
4830                remove_tempfile();
4831                return NULL;
4832        }
4833        remove_tempfile();
4834
4835        return strbuf_detach(&buf, outsize);
4836}
4837
4838size_t fill_textconv(struct userdiff_driver *driver,
4839                     struct diff_filespec *df,
4840                     char **outbuf)
4841{
4842        size_t size;
4843
4844        if (!driver || !driver->textconv) {
4845                if (!DIFF_FILE_VALID(df)) {
4846                        *outbuf = "";
4847                        return 0;
4848                }
4849                if (diff_populate_filespec(df, 0))
4850                        die("unable to read files to diff");
4851                *outbuf = df->data;
4852                return df->size;
4853        }
4854
4855        if (driver->textconv_cache && df->sha1_valid) {
4856                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4857                                          &size);
4858                if (*outbuf)
4859                        return size;
4860        }
4861
4862        *outbuf = run_textconv(driver->textconv, df, &size);
4863        if (!*outbuf)
4864                die("unable to read files to diff");
4865
4866        if (driver->textconv_cache && df->sha1_valid) {
4867                /* ignore errors, as we might be in a readonly repository */
4868                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4869                                size);
4870                /*
4871                 * we could save up changes and flush them all at the end,
4872                 * but we would need an extra call after all diffing is done.
4873                 * Since generating a cache entry is the slow path anyway,
4874                 * this extra overhead probably isn't a big deal.
4875                 */
4876                notes_cache_write(driver->textconv_cache);
4877        }
4878
4879        return size;
4880}