diff.con commit combine-diff: respect textconv attributes (0508fe5)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 400;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static int diff_dirstat_permille_default = 30;
  35static struct diff_options default_diff_options;
  36
  37static char diff_colors[][COLOR_MAXLEN] = {
  38        GIT_COLOR_RESET,
  39        GIT_COLOR_NORMAL,       /* PLAIN */
  40        GIT_COLOR_BOLD,         /* METAINFO */
  41        GIT_COLOR_CYAN,         /* FRAGINFO */
  42        GIT_COLOR_RED,          /* OLD */
  43        GIT_COLOR_GREEN,        /* NEW */
  44        GIT_COLOR_YELLOW,       /* COMMIT */
  45        GIT_COLOR_BG_RED,       /* WHITESPACE */
  46        GIT_COLOR_NORMAL,       /* FUNCINFO */
  47};
  48
  49static int parse_diff_color_slot(const char *var, int ofs)
  50{
  51        if (!strcasecmp(var+ofs, "plain"))
  52                return DIFF_PLAIN;
  53        if (!strcasecmp(var+ofs, "meta"))
  54                return DIFF_METAINFO;
  55        if (!strcasecmp(var+ofs, "frag"))
  56                return DIFF_FRAGINFO;
  57        if (!strcasecmp(var+ofs, "old"))
  58                return DIFF_FILE_OLD;
  59        if (!strcasecmp(var+ofs, "new"))
  60                return DIFF_FILE_NEW;
  61        if (!strcasecmp(var+ofs, "commit"))
  62                return DIFF_COMMIT;
  63        if (!strcasecmp(var+ofs, "whitespace"))
  64                return DIFF_WHITESPACE;
  65        if (!strcasecmp(var+ofs, "func"))
  66                return DIFF_FUNCINFO;
  67        return -1;
  68}
  69
  70static int parse_dirstat_params(struct diff_options *options, const char *params,
  71                                struct strbuf *errmsg)
  72{
  73        const char *p = params;
  74        int p_len, ret = 0;
  75
  76        while (*p) {
  77                p_len = strchrnul(p, ',') - p;
  78                if (!memcmp(p, "changes", p_len)) {
  79                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  80                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  81                } else if (!memcmp(p, "lines", p_len)) {
  82                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  83                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  84                } else if (!memcmp(p, "files", p_len)) {
  85                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  86                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  87                } else if (!memcmp(p, "noncumulative", p_len)) {
  88                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  89                } else if (!memcmp(p, "cumulative", p_len)) {
  90                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  91                } else if (isdigit(*p)) {
  92                        char *end;
  93                        int permille = strtoul(p, &end, 10) * 10;
  94                        if (*end == '.' && isdigit(*++end)) {
  95                                /* only use first digit */
  96                                permille += *end - '0';
  97                                /* .. and ignore any further digits */
  98                                while (isdigit(*++end))
  99                                        ; /* nothing */
 100                        }
 101                        if (end - p == p_len)
 102                                options->dirstat_permille = permille;
 103                        else {
 104                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%.*s'\n"),
 105                                            p_len, p);
 106                                ret++;
 107                        }
 108                } else {
 109                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%.*s'\n"),
 110                                    p_len, p);
 111                        ret++;
 112                }
 113
 114                p += p_len;
 115
 116                if (*p)
 117                        p++; /* more parameters, swallow separator */
 118        }
 119        return ret;
 120}
 121
 122static int git_config_rename(const char *var, const char *value)
 123{
 124        if (!value)
 125                return DIFF_DETECT_RENAME;
 126        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 127                return  DIFF_DETECT_COPY;
 128        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 129}
 130
 131/*
 132 * These are to give UI layer defaults.
 133 * The core-level commands such as git-diff-files should
 134 * never be affected by the setting of diff.renames
 135 * the user happens to have in the configuration file.
 136 */
 137int git_diff_ui_config(const char *var, const char *value, void *cb)
 138{
 139        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 140                diff_use_color_default = git_config_colorbool(var, value, -1);
 141                return 0;
 142        }
 143        if (!strcmp(var, "diff.renames")) {
 144                diff_detect_rename_default = git_config_rename(var, value);
 145                return 0;
 146        }
 147        if (!strcmp(var, "diff.autorefreshindex")) {
 148                diff_auto_refresh_index = git_config_bool(var, value);
 149                return 0;
 150        }
 151        if (!strcmp(var, "diff.mnemonicprefix")) {
 152                diff_mnemonic_prefix = git_config_bool(var, value);
 153                return 0;
 154        }
 155        if (!strcmp(var, "diff.noprefix")) {
 156                diff_no_prefix = git_config_bool(var, value);
 157                return 0;
 158        }
 159        if (!strcmp(var, "diff.external"))
 160                return git_config_string(&external_diff_cmd_cfg, var, value);
 161        if (!strcmp(var, "diff.wordregex"))
 162                return git_config_string(&diff_word_regex_cfg, var, value);
 163
 164        if (!strcmp(var, "diff.ignoresubmodules"))
 165                handle_ignore_submodules_arg(&default_diff_options, value);
 166
 167        return git_diff_basic_config(var, value, cb);
 168}
 169
 170int git_diff_basic_config(const char *var, const char *value, void *cb)
 171{
 172        if (!strcmp(var, "diff.renamelimit")) {
 173                diff_rename_limit_default = git_config_int(var, value);
 174                return 0;
 175        }
 176
 177        switch (userdiff_config(var, value)) {
 178                case 0: break;
 179                case -1: return -1;
 180                default: return 0;
 181        }
 182
 183        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 184                int slot = parse_diff_color_slot(var, 11);
 185                if (slot < 0)
 186                        return 0;
 187                if (!value)
 188                        return config_error_nonbool(var);
 189                color_parse(value, var, diff_colors[slot]);
 190                return 0;
 191        }
 192
 193        /* like GNU diff's --suppress-blank-empty option  */
 194        if (!strcmp(var, "diff.suppressblankempty") ||
 195                        /* for backwards compatibility */
 196                        !strcmp(var, "diff.suppress-blank-empty")) {
 197                diff_suppress_blank_empty = git_config_bool(var, value);
 198                return 0;
 199        }
 200
 201        if (!strcmp(var, "diff.dirstat")) {
 202                struct strbuf errmsg = STRBUF_INIT;
 203                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 204                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 205                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 206                                errmsg.buf);
 207                strbuf_release(&errmsg);
 208                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 209                return 0;
 210        }
 211
 212        if (!prefixcmp(var, "submodule."))
 213                return parse_submodule_config_option(var, value);
 214
 215        return git_color_default_config(var, value, cb);
 216}
 217
 218static char *quote_two(const char *one, const char *two)
 219{
 220        int need_one = quote_c_style(one, NULL, NULL, 1);
 221        int need_two = quote_c_style(two, NULL, NULL, 1);
 222        struct strbuf res = STRBUF_INIT;
 223
 224        if (need_one + need_two) {
 225                strbuf_addch(&res, '"');
 226                quote_c_style(one, &res, NULL, 1);
 227                quote_c_style(two, &res, NULL, 1);
 228                strbuf_addch(&res, '"');
 229        } else {
 230                strbuf_addstr(&res, one);
 231                strbuf_addstr(&res, two);
 232        }
 233        return strbuf_detach(&res, NULL);
 234}
 235
 236static const char *external_diff(void)
 237{
 238        static const char *external_diff_cmd = NULL;
 239        static int done_preparing = 0;
 240
 241        if (done_preparing)
 242                return external_diff_cmd;
 243        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 244        if (!external_diff_cmd)
 245                external_diff_cmd = external_diff_cmd_cfg;
 246        done_preparing = 1;
 247        return external_diff_cmd;
 248}
 249
 250static struct diff_tempfile {
 251        const char *name; /* filename external diff should read from */
 252        char hex[41];
 253        char mode[10];
 254        char tmp_path[PATH_MAX];
 255} diff_temp[2];
 256
 257typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 258
 259struct emit_callback {
 260        int color_diff;
 261        unsigned ws_rule;
 262        int blank_at_eof_in_preimage;
 263        int blank_at_eof_in_postimage;
 264        int lno_in_preimage;
 265        int lno_in_postimage;
 266        sane_truncate_fn truncate;
 267        const char **label_path;
 268        struct diff_words_data *diff_words;
 269        struct diff_options *opt;
 270        int *found_changesp;
 271        struct strbuf *header;
 272};
 273
 274static int count_lines(const char *data, int size)
 275{
 276        int count, ch, completely_empty = 1, nl_just_seen = 0;
 277        count = 0;
 278        while (0 < size--) {
 279                ch = *data++;
 280                if (ch == '\n') {
 281                        count++;
 282                        nl_just_seen = 1;
 283                        completely_empty = 0;
 284                }
 285                else {
 286                        nl_just_seen = 0;
 287                        completely_empty = 0;
 288                }
 289        }
 290        if (completely_empty)
 291                return 0;
 292        if (!nl_just_seen)
 293                count++; /* no trailing newline */
 294        return count;
 295}
 296
 297static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 298{
 299        if (!DIFF_FILE_VALID(one)) {
 300                mf->ptr = (char *)""; /* does not matter */
 301                mf->size = 0;
 302                return 0;
 303        }
 304        else if (diff_populate_filespec(one, 0))
 305                return -1;
 306
 307        mf->ptr = one->data;
 308        mf->size = one->size;
 309        return 0;
 310}
 311
 312/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 313static unsigned long diff_filespec_size(struct diff_filespec *one)
 314{
 315        if (!DIFF_FILE_VALID(one))
 316                return 0;
 317        diff_populate_filespec(one, 1);
 318        return one->size;
 319}
 320
 321static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 322{
 323        char *ptr = mf->ptr;
 324        long size = mf->size;
 325        int cnt = 0;
 326
 327        if (!size)
 328                return cnt;
 329        ptr += size - 1; /* pointing at the very end */
 330        if (*ptr != '\n')
 331                ; /* incomplete line */
 332        else
 333                ptr--; /* skip the last LF */
 334        while (mf->ptr < ptr) {
 335                char *prev_eol;
 336                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 337                        if (*prev_eol == '\n')
 338                                break;
 339                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 340                        break;
 341                cnt++;
 342                ptr = prev_eol - 1;
 343        }
 344        return cnt;
 345}
 346
 347static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 348                               struct emit_callback *ecbdata)
 349{
 350        int l1, l2, at;
 351        unsigned ws_rule = ecbdata->ws_rule;
 352        l1 = count_trailing_blank(mf1, ws_rule);
 353        l2 = count_trailing_blank(mf2, ws_rule);
 354        if (l2 <= l1) {
 355                ecbdata->blank_at_eof_in_preimage = 0;
 356                ecbdata->blank_at_eof_in_postimage = 0;
 357                return;
 358        }
 359        at = count_lines(mf1->ptr, mf1->size);
 360        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 361
 362        at = count_lines(mf2->ptr, mf2->size);
 363        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 364}
 365
 366static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 367                        int first, const char *line, int len)
 368{
 369        int has_trailing_newline, has_trailing_carriage_return;
 370        int nofirst;
 371        FILE *file = o->file;
 372
 373        if (o->output_prefix) {
 374                struct strbuf *msg = NULL;
 375                msg = o->output_prefix(o, o->output_prefix_data);
 376                assert(msg);
 377                fwrite(msg->buf, msg->len, 1, file);
 378        }
 379
 380        if (len == 0) {
 381                has_trailing_newline = (first == '\n');
 382                has_trailing_carriage_return = (!has_trailing_newline &&
 383                                                (first == '\r'));
 384                nofirst = has_trailing_newline || has_trailing_carriage_return;
 385        } else {
 386                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 387                if (has_trailing_newline)
 388                        len--;
 389                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 390                if (has_trailing_carriage_return)
 391                        len--;
 392                nofirst = 0;
 393        }
 394
 395        if (len || !nofirst) {
 396                fputs(set, file);
 397                if (!nofirst)
 398                        fputc(first, file);
 399                fwrite(line, len, 1, file);
 400                fputs(reset, file);
 401        }
 402        if (has_trailing_carriage_return)
 403                fputc('\r', file);
 404        if (has_trailing_newline)
 405                fputc('\n', file);
 406}
 407
 408static void emit_line(struct diff_options *o, const char *set, const char *reset,
 409                      const char *line, int len)
 410{
 411        emit_line_0(o, set, reset, line[0], line+1, len-1);
 412}
 413
 414static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 415{
 416        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 417              ecbdata->blank_at_eof_in_preimage &&
 418              ecbdata->blank_at_eof_in_postimage &&
 419              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 420              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 421                return 0;
 422        return ws_blank_line(line, len, ecbdata->ws_rule);
 423}
 424
 425static void emit_add_line(const char *reset,
 426                          struct emit_callback *ecbdata,
 427                          const char *line, int len)
 428{
 429        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 430        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 431
 432        if (!*ws)
 433                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 434        else if (new_blank_line_at_eof(ecbdata, line, len))
 435                /* Blank line at EOF - paint '+' as well */
 436                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 437        else {
 438                /* Emit just the prefix, then the rest. */
 439                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 440                ws_check_emit(line, len, ecbdata->ws_rule,
 441                              ecbdata->opt->file, set, reset, ws);
 442        }
 443}
 444
 445static void emit_hunk_header(struct emit_callback *ecbdata,
 446                             const char *line, int len)
 447{
 448        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 449        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 450        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 451        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 452        static const char atat[2] = { '@', '@' };
 453        const char *cp, *ep;
 454        struct strbuf msgbuf = STRBUF_INIT;
 455        int org_len = len;
 456        int i = 1;
 457
 458        /*
 459         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 460         * it always is at least 10 bytes long.
 461         */
 462        if (len < 10 ||
 463            memcmp(line, atat, 2) ||
 464            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 465                emit_line(ecbdata->opt, plain, reset, line, len);
 466                return;
 467        }
 468        ep += 2; /* skip over @@ */
 469
 470        /* The hunk header in fraginfo color */
 471        strbuf_add(&msgbuf, frag, strlen(frag));
 472        strbuf_add(&msgbuf, line, ep - line);
 473        strbuf_add(&msgbuf, reset, strlen(reset));
 474
 475        /*
 476         * trailing "\r\n"
 477         */
 478        for ( ; i < 3; i++)
 479                if (line[len - i] == '\r' || line[len - i] == '\n')
 480                        len--;
 481
 482        /* blank before the func header */
 483        for (cp = ep; ep - line < len; ep++)
 484                if (*ep != ' ' && *ep != '\t')
 485                        break;
 486        if (ep != cp) {
 487                strbuf_add(&msgbuf, plain, strlen(plain));
 488                strbuf_add(&msgbuf, cp, ep - cp);
 489                strbuf_add(&msgbuf, reset, strlen(reset));
 490        }
 491
 492        if (ep < line + len) {
 493                strbuf_add(&msgbuf, func, strlen(func));
 494                strbuf_add(&msgbuf, ep, line + len - ep);
 495                strbuf_add(&msgbuf, reset, strlen(reset));
 496        }
 497
 498        strbuf_add(&msgbuf, line + len, org_len - len);
 499        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 500        strbuf_release(&msgbuf);
 501}
 502
 503static struct diff_tempfile *claim_diff_tempfile(void) {
 504        int i;
 505        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 506                if (!diff_temp[i].name)
 507                        return diff_temp + i;
 508        die("BUG: diff is failing to clean up its tempfiles");
 509}
 510
 511static int remove_tempfile_installed;
 512
 513static void remove_tempfile(void)
 514{
 515        int i;
 516        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 517                if (diff_temp[i].name == diff_temp[i].tmp_path)
 518                        unlink_or_warn(diff_temp[i].name);
 519                diff_temp[i].name = NULL;
 520        }
 521}
 522
 523static void remove_tempfile_on_signal(int signo)
 524{
 525        remove_tempfile();
 526        sigchain_pop(signo);
 527        raise(signo);
 528}
 529
 530static void print_line_count(FILE *file, int count)
 531{
 532        switch (count) {
 533        case 0:
 534                fprintf(file, "0,0");
 535                break;
 536        case 1:
 537                fprintf(file, "1");
 538                break;
 539        default:
 540                fprintf(file, "1,%d", count);
 541                break;
 542        }
 543}
 544
 545static void emit_rewrite_lines(struct emit_callback *ecb,
 546                               int prefix, const char *data, int size)
 547{
 548        const char *endp = NULL;
 549        static const char *nneof = " No newline at end of file\n";
 550        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 551        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 552
 553        while (0 < size) {
 554                int len;
 555
 556                endp = memchr(data, '\n', size);
 557                len = endp ? (endp - data + 1) : size;
 558                if (prefix != '+') {
 559                        ecb->lno_in_preimage++;
 560                        emit_line_0(ecb->opt, old, reset, '-',
 561                                    data, len);
 562                } else {
 563                        ecb->lno_in_postimage++;
 564                        emit_add_line(reset, ecb, data, len);
 565                }
 566                size -= len;
 567                data += len;
 568        }
 569        if (!endp) {
 570                const char *plain = diff_get_color(ecb->color_diff,
 571                                                   DIFF_PLAIN);
 572                emit_line_0(ecb->opt, plain, reset, '\\',
 573                            nneof, strlen(nneof));
 574        }
 575}
 576
 577static void emit_rewrite_diff(const char *name_a,
 578                              const char *name_b,
 579                              struct diff_filespec *one,
 580                              struct diff_filespec *two,
 581                              struct userdiff_driver *textconv_one,
 582                              struct userdiff_driver *textconv_two,
 583                              struct diff_options *o)
 584{
 585        int lc_a, lc_b;
 586        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 587        const char *name_a_tab, *name_b_tab;
 588        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 589        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 590        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 591        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 592        const char *a_prefix, *b_prefix;
 593        char *data_one, *data_two;
 594        size_t size_one, size_two;
 595        struct emit_callback ecbdata;
 596        char *line_prefix = "";
 597        struct strbuf *msgbuf;
 598
 599        if (o && o->output_prefix) {
 600                msgbuf = o->output_prefix(o, o->output_prefix_data);
 601                line_prefix = msgbuf->buf;
 602        }
 603
 604        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 605                a_prefix = o->b_prefix;
 606                b_prefix = o->a_prefix;
 607        } else {
 608                a_prefix = o->a_prefix;
 609                b_prefix = o->b_prefix;
 610        }
 611
 612        name_a += (*name_a == '/');
 613        name_b += (*name_b == '/');
 614        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 615        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 616
 617        strbuf_reset(&a_name);
 618        strbuf_reset(&b_name);
 619        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 620        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 621
 622        size_one = fill_textconv(textconv_one, one, &data_one);
 623        size_two = fill_textconv(textconv_two, two, &data_two);
 624
 625        memset(&ecbdata, 0, sizeof(ecbdata));
 626        ecbdata.color_diff = color_diff;
 627        ecbdata.found_changesp = &o->found_changes;
 628        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 629        ecbdata.opt = o;
 630        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 631                mmfile_t mf1, mf2;
 632                mf1.ptr = (char *)data_one;
 633                mf2.ptr = (char *)data_two;
 634                mf1.size = size_one;
 635                mf2.size = size_two;
 636                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 637        }
 638        ecbdata.lno_in_preimage = 1;
 639        ecbdata.lno_in_postimage = 1;
 640
 641        lc_a = count_lines(data_one, size_one);
 642        lc_b = count_lines(data_two, size_two);
 643        fprintf(o->file,
 644                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 645                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 646                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 647                line_prefix, fraginfo);
 648        if (!o->irreversible_delete)
 649                print_line_count(o->file, lc_a);
 650        else
 651                fprintf(o->file, "?,?");
 652        fprintf(o->file, " +");
 653        print_line_count(o->file, lc_b);
 654        fprintf(o->file, " @@%s\n", reset);
 655        if (lc_a && !o->irreversible_delete)
 656                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 657        if (lc_b)
 658                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 659        if (textconv_one)
 660                free((char *)data_one);
 661        if (textconv_two)
 662                free((char *)data_two);
 663}
 664
 665struct diff_words_buffer {
 666        mmfile_t text;
 667        long alloc;
 668        struct diff_words_orig {
 669                const char *begin, *end;
 670        } *orig;
 671        int orig_nr, orig_alloc;
 672};
 673
 674static void diff_words_append(char *line, unsigned long len,
 675                struct diff_words_buffer *buffer)
 676{
 677        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 678        line++;
 679        len--;
 680        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 681        buffer->text.size += len;
 682        buffer->text.ptr[buffer->text.size] = '\0';
 683}
 684
 685struct diff_words_style_elem {
 686        const char *prefix;
 687        const char *suffix;
 688        const char *color; /* NULL; filled in by the setup code if
 689                            * color is enabled */
 690};
 691
 692struct diff_words_style {
 693        enum diff_words_type type;
 694        struct diff_words_style_elem new, old, ctx;
 695        const char *newline;
 696};
 697
 698static struct diff_words_style diff_words_styles[] = {
 699        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 700        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 701        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 702};
 703
 704struct diff_words_data {
 705        struct diff_words_buffer minus, plus;
 706        const char *current_plus;
 707        int last_minus;
 708        struct diff_options *opt;
 709        regex_t *word_regex;
 710        enum diff_words_type type;
 711        struct diff_words_style *style;
 712};
 713
 714static int fn_out_diff_words_write_helper(FILE *fp,
 715                                          struct diff_words_style_elem *st_el,
 716                                          const char *newline,
 717                                          size_t count, const char *buf,
 718                                          const char *line_prefix)
 719{
 720        int print = 0;
 721
 722        while (count) {
 723                char *p = memchr(buf, '\n', count);
 724                if (print)
 725                        fputs(line_prefix, fp);
 726                if (p != buf) {
 727                        if (st_el->color && fputs(st_el->color, fp) < 0)
 728                                return -1;
 729                        if (fputs(st_el->prefix, fp) < 0 ||
 730                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 731                            fputs(st_el->suffix, fp) < 0)
 732                                return -1;
 733                        if (st_el->color && *st_el->color
 734                            && fputs(GIT_COLOR_RESET, fp) < 0)
 735                                return -1;
 736                }
 737                if (!p)
 738                        return 0;
 739                if (fputs(newline, fp) < 0)
 740                        return -1;
 741                count -= p + 1 - buf;
 742                buf = p + 1;
 743                print = 1;
 744        }
 745        return 0;
 746}
 747
 748/*
 749 * '--color-words' algorithm can be described as:
 750 *
 751 *   1. collect a the minus/plus lines of a diff hunk, divided into
 752 *      minus-lines and plus-lines;
 753 *
 754 *   2. break both minus-lines and plus-lines into words and
 755 *      place them into two mmfile_t with one word for each line;
 756 *
 757 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 758 *
 759 * And for the common parts of the both file, we output the plus side text.
 760 * diff_words->current_plus is used to trace the current position of the plus file
 761 * which printed. diff_words->last_minus is used to trace the last minus word
 762 * printed.
 763 *
 764 * For '--graph' to work with '--color-words', we need to output the graph prefix
 765 * on each line of color words output. Generally, there are two conditions on
 766 * which we should output the prefix.
 767 *
 768 *   1. diff_words->last_minus == 0 &&
 769 *      diff_words->current_plus == diff_words->plus.text.ptr
 770 *
 771 *      that is: the plus text must start as a new line, and if there is no minus
 772 *      word printed, a graph prefix must be printed.
 773 *
 774 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 775 *      *(diff_words->current_plus - 1) == '\n'
 776 *
 777 *      that is: a graph prefix must be printed following a '\n'
 778 */
 779static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 780{
 781        if ((diff_words->last_minus == 0 &&
 782                diff_words->current_plus == diff_words->plus.text.ptr) ||
 783                (diff_words->current_plus > diff_words->plus.text.ptr &&
 784                *(diff_words->current_plus - 1) == '\n')) {
 785                return 1;
 786        } else {
 787                return 0;
 788        }
 789}
 790
 791static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 792{
 793        struct diff_words_data *diff_words = priv;
 794        struct diff_words_style *style = diff_words->style;
 795        int minus_first, minus_len, plus_first, plus_len;
 796        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 797        struct diff_options *opt = diff_words->opt;
 798        struct strbuf *msgbuf;
 799        char *line_prefix = "";
 800
 801        if (line[0] != '@' || parse_hunk_header(line, len,
 802                        &minus_first, &minus_len, &plus_first, &plus_len))
 803                return;
 804
 805        assert(opt);
 806        if (opt->output_prefix) {
 807                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 808                line_prefix = msgbuf->buf;
 809        }
 810
 811        /* POSIX requires that first be decremented by one if len == 0... */
 812        if (minus_len) {
 813                minus_begin = diff_words->minus.orig[minus_first].begin;
 814                minus_end =
 815                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 816        } else
 817                minus_begin = minus_end =
 818                        diff_words->minus.orig[minus_first].end;
 819
 820        if (plus_len) {
 821                plus_begin = diff_words->plus.orig[plus_first].begin;
 822                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 823        } else
 824                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 825
 826        if (color_words_output_graph_prefix(diff_words)) {
 827                fputs(line_prefix, diff_words->opt->file);
 828        }
 829        if (diff_words->current_plus != plus_begin) {
 830                fn_out_diff_words_write_helper(diff_words->opt->file,
 831                                &style->ctx, style->newline,
 832                                plus_begin - diff_words->current_plus,
 833                                diff_words->current_plus, line_prefix);
 834                if (*(plus_begin - 1) == '\n')
 835                        fputs(line_prefix, diff_words->opt->file);
 836        }
 837        if (minus_begin != minus_end) {
 838                fn_out_diff_words_write_helper(diff_words->opt->file,
 839                                &style->old, style->newline,
 840                                minus_end - minus_begin, minus_begin,
 841                                line_prefix);
 842        }
 843        if (plus_begin != plus_end) {
 844                fn_out_diff_words_write_helper(diff_words->opt->file,
 845                                &style->new, style->newline,
 846                                plus_end - plus_begin, plus_begin,
 847                                line_prefix);
 848        }
 849
 850        diff_words->current_plus = plus_end;
 851        diff_words->last_minus = minus_first;
 852}
 853
 854/* This function starts looking at *begin, and returns 0 iff a word was found. */
 855static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 856                int *begin, int *end)
 857{
 858        if (word_regex && *begin < buffer->size) {
 859                regmatch_t match[1];
 860                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 861                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 862                                        '\n', match[0].rm_eo - match[0].rm_so);
 863                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 864                        *begin += match[0].rm_so;
 865                        return *begin >= *end;
 866                }
 867                return -1;
 868        }
 869
 870        /* find the next word */
 871        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 872                (*begin)++;
 873        if (*begin >= buffer->size)
 874                return -1;
 875
 876        /* find the end of the word */
 877        *end = *begin + 1;
 878        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 879                (*end)++;
 880
 881        return 0;
 882}
 883
 884/*
 885 * This function splits the words in buffer->text, stores the list with
 886 * newline separator into out, and saves the offsets of the original words
 887 * in buffer->orig.
 888 */
 889static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 890                regex_t *word_regex)
 891{
 892        int i, j;
 893        long alloc = 0;
 894
 895        out->size = 0;
 896        out->ptr = NULL;
 897
 898        /* fake an empty "0th" word */
 899        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 900        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 901        buffer->orig_nr = 1;
 902
 903        for (i = 0; i < buffer->text.size; i++) {
 904                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 905                        return;
 906
 907                /* store original boundaries */
 908                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 909                                buffer->orig_alloc);
 910                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 911                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 912                buffer->orig_nr++;
 913
 914                /* store one word */
 915                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 916                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 917                out->ptr[out->size + j - i] = '\n';
 918                out->size += j - i + 1;
 919
 920                i = j - 1;
 921        }
 922}
 923
 924/* this executes the word diff on the accumulated buffers */
 925static void diff_words_show(struct diff_words_data *diff_words)
 926{
 927        xpparam_t xpp;
 928        xdemitconf_t xecfg;
 929        mmfile_t minus, plus;
 930        struct diff_words_style *style = diff_words->style;
 931
 932        struct diff_options *opt = diff_words->opt;
 933        struct strbuf *msgbuf;
 934        char *line_prefix = "";
 935
 936        assert(opt);
 937        if (opt->output_prefix) {
 938                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 939                line_prefix = msgbuf->buf;
 940        }
 941
 942        /* special case: only removal */
 943        if (!diff_words->plus.text.size) {
 944                fputs(line_prefix, diff_words->opt->file);
 945                fn_out_diff_words_write_helper(diff_words->opt->file,
 946                        &style->old, style->newline,
 947                        diff_words->minus.text.size,
 948                        diff_words->minus.text.ptr, line_prefix);
 949                diff_words->minus.text.size = 0;
 950                return;
 951        }
 952
 953        diff_words->current_plus = diff_words->plus.text.ptr;
 954        diff_words->last_minus = 0;
 955
 956        memset(&xpp, 0, sizeof(xpp));
 957        memset(&xecfg, 0, sizeof(xecfg));
 958        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 959        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 960        xpp.flags = 0;
 961        /* as only the hunk header will be parsed, we need a 0-context */
 962        xecfg.ctxlen = 0;
 963        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 964                      &xpp, &xecfg);
 965        free(minus.ptr);
 966        free(plus.ptr);
 967        if (diff_words->current_plus != diff_words->plus.text.ptr +
 968                        diff_words->plus.text.size) {
 969                if (color_words_output_graph_prefix(diff_words))
 970                        fputs(line_prefix, diff_words->opt->file);
 971                fn_out_diff_words_write_helper(diff_words->opt->file,
 972                        &style->ctx, style->newline,
 973                        diff_words->plus.text.ptr + diff_words->plus.text.size
 974                        - diff_words->current_plus, diff_words->current_plus,
 975                        line_prefix);
 976        }
 977        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 978}
 979
 980/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 981static void diff_words_flush(struct emit_callback *ecbdata)
 982{
 983        if (ecbdata->diff_words->minus.text.size ||
 984            ecbdata->diff_words->plus.text.size)
 985                diff_words_show(ecbdata->diff_words);
 986}
 987
 988static void free_diff_words_data(struct emit_callback *ecbdata)
 989{
 990        if (ecbdata->diff_words) {
 991                diff_words_flush(ecbdata);
 992                free (ecbdata->diff_words->minus.text.ptr);
 993                free (ecbdata->diff_words->minus.orig);
 994                free (ecbdata->diff_words->plus.text.ptr);
 995                free (ecbdata->diff_words->plus.orig);
 996                if (ecbdata->diff_words->word_regex) {
 997                        regfree(ecbdata->diff_words->word_regex);
 998                        free(ecbdata->diff_words->word_regex);
 999                }
1000                free(ecbdata->diff_words);
1001                ecbdata->diff_words = NULL;
1002        }
1003}
1004
1005const char *diff_get_color(int diff_use_color, enum color_diff ix)
1006{
1007        if (diff_use_color)
1008                return diff_colors[ix];
1009        return "";
1010}
1011
1012static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1013{
1014        const char *cp;
1015        unsigned long allot;
1016        size_t l = len;
1017
1018        if (ecb->truncate)
1019                return ecb->truncate(line, len);
1020        cp = line;
1021        allot = l;
1022        while (0 < l) {
1023                (void) utf8_width(&cp, &l);
1024                if (!cp)
1025                        break; /* truncated in the middle? */
1026        }
1027        return allot - l;
1028}
1029
1030static void find_lno(const char *line, struct emit_callback *ecbdata)
1031{
1032        const char *p;
1033        ecbdata->lno_in_preimage = 0;
1034        ecbdata->lno_in_postimage = 0;
1035        p = strchr(line, '-');
1036        if (!p)
1037                return; /* cannot happen */
1038        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1039        p = strchr(p, '+');
1040        if (!p)
1041                return; /* cannot happen */
1042        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1043}
1044
1045static void fn_out_consume(void *priv, char *line, unsigned long len)
1046{
1047        struct emit_callback *ecbdata = priv;
1048        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1049        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1050        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1051        struct diff_options *o = ecbdata->opt;
1052        char *line_prefix = "";
1053        struct strbuf *msgbuf;
1054
1055        if (o && o->output_prefix) {
1056                msgbuf = o->output_prefix(o, o->output_prefix_data);
1057                line_prefix = msgbuf->buf;
1058        }
1059
1060        if (ecbdata->header) {
1061                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1062                strbuf_reset(ecbdata->header);
1063                ecbdata->header = NULL;
1064        }
1065        *(ecbdata->found_changesp) = 1;
1066
1067        if (ecbdata->label_path[0]) {
1068                const char *name_a_tab, *name_b_tab;
1069
1070                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1071                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1072
1073                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1074                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1075                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1076                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1077                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1078        }
1079
1080        if (diff_suppress_blank_empty
1081            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1082                line[0] = '\n';
1083                len = 1;
1084        }
1085
1086        if (line[0] == '@') {
1087                if (ecbdata->diff_words)
1088                        diff_words_flush(ecbdata);
1089                len = sane_truncate_line(ecbdata, line, len);
1090                find_lno(line, ecbdata);
1091                emit_hunk_header(ecbdata, line, len);
1092                if (line[len-1] != '\n')
1093                        putc('\n', ecbdata->opt->file);
1094                return;
1095        }
1096
1097        if (len < 1) {
1098                emit_line(ecbdata->opt, reset, reset, line, len);
1099                if (ecbdata->diff_words
1100                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1101                        fputs("~\n", ecbdata->opt->file);
1102                return;
1103        }
1104
1105        if (ecbdata->diff_words) {
1106                if (line[0] == '-') {
1107                        diff_words_append(line, len,
1108                                          &ecbdata->diff_words->minus);
1109                        return;
1110                } else if (line[0] == '+') {
1111                        diff_words_append(line, len,
1112                                          &ecbdata->diff_words->plus);
1113                        return;
1114                }
1115                diff_words_flush(ecbdata);
1116                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1117                        emit_line(ecbdata->opt, plain, reset, line, len);
1118                        fputs("~\n", ecbdata->opt->file);
1119                } else {
1120                        /* don't print the prefix character */
1121                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1122                }
1123                return;
1124        }
1125
1126        if (line[0] != '+') {
1127                const char *color =
1128                        diff_get_color(ecbdata->color_diff,
1129                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1130                ecbdata->lno_in_preimage++;
1131                if (line[0] == ' ')
1132                        ecbdata->lno_in_postimage++;
1133                emit_line(ecbdata->opt, color, reset, line, len);
1134        } else {
1135                ecbdata->lno_in_postimage++;
1136                emit_add_line(reset, ecbdata, line + 1, len - 1);
1137        }
1138}
1139
1140static char *pprint_rename(const char *a, const char *b)
1141{
1142        const char *old = a;
1143        const char *new = b;
1144        struct strbuf name = STRBUF_INIT;
1145        int pfx_length, sfx_length;
1146        int len_a = strlen(a);
1147        int len_b = strlen(b);
1148        int a_midlen, b_midlen;
1149        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1150        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1151
1152        if (qlen_a || qlen_b) {
1153                quote_c_style(a, &name, NULL, 0);
1154                strbuf_addstr(&name, " => ");
1155                quote_c_style(b, &name, NULL, 0);
1156                return strbuf_detach(&name, NULL);
1157        }
1158
1159        /* Find common prefix */
1160        pfx_length = 0;
1161        while (*old && *new && *old == *new) {
1162                if (*old == '/')
1163                        pfx_length = old - a + 1;
1164                old++;
1165                new++;
1166        }
1167
1168        /* Find common suffix */
1169        old = a + len_a;
1170        new = b + len_b;
1171        sfx_length = 0;
1172        while (a <= old && b <= new && *old == *new) {
1173                if (*old == '/')
1174                        sfx_length = len_a - (old - a);
1175                old--;
1176                new--;
1177        }
1178
1179        /*
1180         * pfx{mid-a => mid-b}sfx
1181         * {pfx-a => pfx-b}sfx
1182         * pfx{sfx-a => sfx-b}
1183         * name-a => name-b
1184         */
1185        a_midlen = len_a - pfx_length - sfx_length;
1186        b_midlen = len_b - pfx_length - sfx_length;
1187        if (a_midlen < 0)
1188                a_midlen = 0;
1189        if (b_midlen < 0)
1190                b_midlen = 0;
1191
1192        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1193        if (pfx_length + sfx_length) {
1194                strbuf_add(&name, a, pfx_length);
1195                strbuf_addch(&name, '{');
1196        }
1197        strbuf_add(&name, a + pfx_length, a_midlen);
1198        strbuf_addstr(&name, " => ");
1199        strbuf_add(&name, b + pfx_length, b_midlen);
1200        if (pfx_length + sfx_length) {
1201                strbuf_addch(&name, '}');
1202                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1203        }
1204        return strbuf_detach(&name, NULL);
1205}
1206
1207struct diffstat_t {
1208        int nr;
1209        int alloc;
1210        struct diffstat_file {
1211                char *from_name;
1212                char *name;
1213                char *print_name;
1214                unsigned is_unmerged:1;
1215                unsigned is_binary:1;
1216                unsigned is_renamed:1;
1217                uintmax_t added, deleted;
1218        } **files;
1219};
1220
1221static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1222                                          const char *name_a,
1223                                          const char *name_b)
1224{
1225        struct diffstat_file *x;
1226        x = xcalloc(sizeof (*x), 1);
1227        if (diffstat->nr == diffstat->alloc) {
1228                diffstat->alloc = alloc_nr(diffstat->alloc);
1229                diffstat->files = xrealloc(diffstat->files,
1230                                diffstat->alloc * sizeof(x));
1231        }
1232        diffstat->files[diffstat->nr++] = x;
1233        if (name_b) {
1234                x->from_name = xstrdup(name_a);
1235                x->name = xstrdup(name_b);
1236                x->is_renamed = 1;
1237        }
1238        else {
1239                x->from_name = NULL;
1240                x->name = xstrdup(name_a);
1241        }
1242        return x;
1243}
1244
1245static void diffstat_consume(void *priv, char *line, unsigned long len)
1246{
1247        struct diffstat_t *diffstat = priv;
1248        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1249
1250        if (line[0] == '+')
1251                x->added++;
1252        else if (line[0] == '-')
1253                x->deleted++;
1254}
1255
1256const char mime_boundary_leader[] = "------------";
1257
1258static int scale_linear(int it, int width, int max_change)
1259{
1260        /*
1261         * make sure that at least one '-' is printed if there were deletions,
1262         * and likewise for '+'.
1263         */
1264        if (max_change < 2)
1265                return it;
1266        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1267}
1268
1269static void show_name(FILE *file,
1270                      const char *prefix, const char *name, int len)
1271{
1272        fprintf(file, " %s%-*s |", prefix, len, name);
1273}
1274
1275static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1276{
1277        if (cnt <= 0)
1278                return;
1279        fprintf(file, "%s", set);
1280        while (cnt--)
1281                putc(ch, file);
1282        fprintf(file, "%s", reset);
1283}
1284
1285static void fill_print_name(struct diffstat_file *file)
1286{
1287        char *pname;
1288
1289        if (file->print_name)
1290                return;
1291
1292        if (!file->is_renamed) {
1293                struct strbuf buf = STRBUF_INIT;
1294                if (quote_c_style(file->name, &buf, NULL, 0)) {
1295                        pname = strbuf_detach(&buf, NULL);
1296                } else {
1297                        pname = file->name;
1298                        strbuf_release(&buf);
1299                }
1300        } else {
1301                pname = pprint_rename(file->from_name, file->name);
1302        }
1303        file->print_name = pname;
1304}
1305
1306static void show_stats(struct diffstat_t *data, struct diff_options *options)
1307{
1308        int i, len, add, del, adds = 0, dels = 0;
1309        uintmax_t max_change = 0, max_len = 0;
1310        int total_files = data->nr;
1311        int width, name_width;
1312        const char *reset, *add_c, *del_c;
1313        const char *line_prefix = "";
1314        struct strbuf *msg = NULL;
1315
1316        if (data->nr == 0)
1317                return;
1318
1319        if (options->output_prefix) {
1320                msg = options->output_prefix(options, options->output_prefix_data);
1321                line_prefix = msg->buf;
1322        }
1323
1324        width = options->stat_width ? options->stat_width : 80;
1325        name_width = options->stat_name_width ? options->stat_name_width : 50;
1326
1327        /* Sanity: give at least 5 columns to the graph,
1328         * but leave at least 10 columns for the name.
1329         */
1330        if (width < 25)
1331                width = 25;
1332        if (name_width < 10)
1333                name_width = 10;
1334        else if (width < name_width + 15)
1335                name_width = width - 15;
1336
1337        /* Find the longest filename and max number of changes */
1338        reset = diff_get_color_opt(options, DIFF_RESET);
1339        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1340        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1341
1342        for (i = 0; i < data->nr; i++) {
1343                struct diffstat_file *file = data->files[i];
1344                uintmax_t change = file->added + file->deleted;
1345                fill_print_name(file);
1346                len = strlen(file->print_name);
1347                if (max_len < len)
1348                        max_len = len;
1349
1350                if (file->is_binary || file->is_unmerged)
1351                        continue;
1352                if (max_change < change)
1353                        max_change = change;
1354        }
1355
1356        /* Compute the width of the graph part;
1357         * 10 is for one blank at the beginning of the line plus
1358         * " | count " between the name and the graph.
1359         *
1360         * From here on, name_width is the width of the name area,
1361         * and width is the width of the graph area.
1362         */
1363        name_width = (name_width < max_len) ? name_width : max_len;
1364        if (width < (name_width + 10) + max_change)
1365                width = width - (name_width + 10);
1366        else
1367                width = max_change;
1368
1369        for (i = 0; i < data->nr; i++) {
1370                const char *prefix = "";
1371                char *name = data->files[i]->print_name;
1372                uintmax_t added = data->files[i]->added;
1373                uintmax_t deleted = data->files[i]->deleted;
1374                int name_len;
1375
1376                /*
1377                 * "scale" the filename
1378                 */
1379                len = name_width;
1380                name_len = strlen(name);
1381                if (name_width < name_len) {
1382                        char *slash;
1383                        prefix = "...";
1384                        len -= 3;
1385                        name += name_len - len;
1386                        slash = strchr(name, '/');
1387                        if (slash)
1388                                name = slash;
1389                }
1390
1391                if (data->files[i]->is_binary) {
1392                        fprintf(options->file, "%s", line_prefix);
1393                        show_name(options->file, prefix, name, len);
1394                        fprintf(options->file, "  Bin ");
1395                        fprintf(options->file, "%s%"PRIuMAX"%s",
1396                                del_c, deleted, reset);
1397                        fprintf(options->file, " -> ");
1398                        fprintf(options->file, "%s%"PRIuMAX"%s",
1399                                add_c, added, reset);
1400                        fprintf(options->file, " bytes");
1401                        fprintf(options->file, "\n");
1402                        continue;
1403                }
1404                else if (data->files[i]->is_unmerged) {
1405                        fprintf(options->file, "%s", line_prefix);
1406                        show_name(options->file, prefix, name, len);
1407                        fprintf(options->file, "  Unmerged\n");
1408                        continue;
1409                }
1410                else if (!data->files[i]->is_renamed &&
1411                         (added + deleted == 0)) {
1412                        total_files--;
1413                        continue;
1414                }
1415
1416                /*
1417                 * scale the add/delete
1418                 */
1419                add = added;
1420                del = deleted;
1421                adds += add;
1422                dels += del;
1423
1424                if (width <= max_change) {
1425                        add = scale_linear(add, width, max_change);
1426                        del = scale_linear(del, width, max_change);
1427                }
1428                fprintf(options->file, "%s", line_prefix);
1429                show_name(options->file, prefix, name, len);
1430                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1431                                added + deleted ? " " : "");
1432                show_graph(options->file, '+', add, add_c, reset);
1433                show_graph(options->file, '-', del, del_c, reset);
1434                fprintf(options->file, "\n");
1435        }
1436        fprintf(options->file, "%s", line_prefix);
1437        fprintf(options->file,
1438               " %d files changed, %d insertions(+), %d deletions(-)\n",
1439               total_files, adds, dels);
1440}
1441
1442static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1443{
1444        int i, adds = 0, dels = 0, total_files = data->nr;
1445
1446        if (data->nr == 0)
1447                return;
1448
1449        for (i = 0; i < data->nr; i++) {
1450                if (!data->files[i]->is_binary &&
1451                    !data->files[i]->is_unmerged) {
1452                        int added = data->files[i]->added;
1453                        int deleted= data->files[i]->deleted;
1454                        if (!data->files[i]->is_renamed &&
1455                            (added + deleted == 0)) {
1456                                total_files--;
1457                        } else {
1458                                adds += added;
1459                                dels += deleted;
1460                        }
1461                }
1462        }
1463        if (options->output_prefix) {
1464                struct strbuf *msg = NULL;
1465                msg = options->output_prefix(options,
1466                                options->output_prefix_data);
1467                fprintf(options->file, "%s", msg->buf);
1468        }
1469        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1470               total_files, adds, dels);
1471}
1472
1473static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1474{
1475        int i;
1476
1477        if (data->nr == 0)
1478                return;
1479
1480        for (i = 0; i < data->nr; i++) {
1481                struct diffstat_file *file = data->files[i];
1482
1483                if (options->output_prefix) {
1484                        struct strbuf *msg = NULL;
1485                        msg = options->output_prefix(options,
1486                                        options->output_prefix_data);
1487                        fprintf(options->file, "%s", msg->buf);
1488                }
1489
1490                if (file->is_binary)
1491                        fprintf(options->file, "-\t-\t");
1492                else
1493                        fprintf(options->file,
1494                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1495                                file->added, file->deleted);
1496                if (options->line_termination) {
1497                        fill_print_name(file);
1498                        if (!file->is_renamed)
1499                                write_name_quoted(file->name, options->file,
1500                                                  options->line_termination);
1501                        else {
1502                                fputs(file->print_name, options->file);
1503                                putc(options->line_termination, options->file);
1504                        }
1505                } else {
1506                        if (file->is_renamed) {
1507                                putc('\0', options->file);
1508                                write_name_quoted(file->from_name, options->file, '\0');
1509                        }
1510                        write_name_quoted(file->name, options->file, '\0');
1511                }
1512        }
1513}
1514
1515struct dirstat_file {
1516        const char *name;
1517        unsigned long changed;
1518};
1519
1520struct dirstat_dir {
1521        struct dirstat_file *files;
1522        int alloc, nr, permille, cumulative;
1523};
1524
1525static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1526                unsigned long changed, const char *base, int baselen)
1527{
1528        unsigned long this_dir = 0;
1529        unsigned int sources = 0;
1530        const char *line_prefix = "";
1531        struct strbuf *msg = NULL;
1532
1533        if (opt->output_prefix) {
1534                msg = opt->output_prefix(opt, opt->output_prefix_data);
1535                line_prefix = msg->buf;
1536        }
1537
1538        while (dir->nr) {
1539                struct dirstat_file *f = dir->files;
1540                int namelen = strlen(f->name);
1541                unsigned long this;
1542                char *slash;
1543
1544                if (namelen < baselen)
1545                        break;
1546                if (memcmp(f->name, base, baselen))
1547                        break;
1548                slash = strchr(f->name + baselen, '/');
1549                if (slash) {
1550                        int newbaselen = slash + 1 - f->name;
1551                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1552                        sources++;
1553                } else {
1554                        this = f->changed;
1555                        dir->files++;
1556                        dir->nr--;
1557                        sources += 2;
1558                }
1559                this_dir += this;
1560        }
1561
1562        /*
1563         * We don't report dirstat's for
1564         *  - the top level
1565         *  - or cases where everything came from a single directory
1566         *    under this directory (sources == 1).
1567         */
1568        if (baselen && sources != 1) {
1569                if (this_dir) {
1570                        int permille = this_dir * 1000 / changed;
1571                        if (permille >= dir->permille) {
1572                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1573                                        permille / 10, permille % 10, baselen, base);
1574                                if (!dir->cumulative)
1575                                        return 0;
1576                        }
1577                }
1578        }
1579        return this_dir;
1580}
1581
1582static int dirstat_compare(const void *_a, const void *_b)
1583{
1584        const struct dirstat_file *a = _a;
1585        const struct dirstat_file *b = _b;
1586        return strcmp(a->name, b->name);
1587}
1588
1589static void show_dirstat(struct diff_options *options)
1590{
1591        int i;
1592        unsigned long changed;
1593        struct dirstat_dir dir;
1594        struct diff_queue_struct *q = &diff_queued_diff;
1595
1596        dir.files = NULL;
1597        dir.alloc = 0;
1598        dir.nr = 0;
1599        dir.permille = options->dirstat_permille;
1600        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1601
1602        changed = 0;
1603        for (i = 0; i < q->nr; i++) {
1604                struct diff_filepair *p = q->queue[i];
1605                const char *name;
1606                unsigned long copied, added, damage;
1607                int content_changed;
1608
1609                name = p->two->path ? p->two->path : p->one->path;
1610
1611                if (p->one->sha1_valid && p->two->sha1_valid)
1612                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1613                else
1614                        content_changed = 1;
1615
1616                if (!content_changed) {
1617                        /*
1618                         * The SHA1 has not changed, so pre-/post-content is
1619                         * identical. We can therefore skip looking at the
1620                         * file contents altogether.
1621                         */
1622                        damage = 0;
1623                        goto found_damage;
1624                }
1625
1626                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1627                        /*
1628                         * In --dirstat-by-file mode, we don't really need to
1629                         * look at the actual file contents at all.
1630                         * The fact that the SHA1 changed is enough for us to
1631                         * add this file to the list of results
1632                         * (with each file contributing equal damage).
1633                         */
1634                        damage = 1;
1635                        goto found_damage;
1636                }
1637
1638                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1639                        diff_populate_filespec(p->one, 0);
1640                        diff_populate_filespec(p->two, 0);
1641                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1642                                               &copied, &added);
1643                        diff_free_filespec_data(p->one);
1644                        diff_free_filespec_data(p->two);
1645                } else if (DIFF_FILE_VALID(p->one)) {
1646                        diff_populate_filespec(p->one, 1);
1647                        copied = added = 0;
1648                        diff_free_filespec_data(p->one);
1649                } else if (DIFF_FILE_VALID(p->two)) {
1650                        diff_populate_filespec(p->two, 1);
1651                        copied = 0;
1652                        added = p->two->size;
1653                        diff_free_filespec_data(p->two);
1654                } else
1655                        continue;
1656
1657                /*
1658                 * Original minus copied is the removed material,
1659                 * added is the new material.  They are both damages
1660                 * made to the preimage.
1661                 * If the resulting damage is zero, we know that
1662                 * diffcore_count_changes() considers the two entries to
1663                 * be identical, but since content_changed is true, we
1664                 * know that there must have been _some_ kind of change,
1665                 * so we force all entries to have damage > 0.
1666                 */
1667                damage = (p->one->size - copied) + added;
1668                if (!damage)
1669                        damage = 1;
1670
1671found_damage:
1672                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1673                dir.files[dir.nr].name = name;
1674                dir.files[dir.nr].changed = damage;
1675                changed += damage;
1676                dir.nr++;
1677        }
1678
1679        /* This can happen even with many files, if everything was renames */
1680        if (!changed)
1681                return;
1682
1683        /* Show all directories with more than x% of the changes */
1684        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1685        gather_dirstat(options, &dir, changed, "", 0);
1686}
1687
1688static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1689{
1690        int i;
1691        unsigned long changed;
1692        struct dirstat_dir dir;
1693
1694        if (data->nr == 0)
1695                return;
1696
1697        dir.files = NULL;
1698        dir.alloc = 0;
1699        dir.nr = 0;
1700        dir.permille = options->dirstat_permille;
1701        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1702
1703        changed = 0;
1704        for (i = 0; i < data->nr; i++) {
1705                struct diffstat_file *file = data->files[i];
1706                unsigned long damage = file->added + file->deleted;
1707                if (file->is_binary)
1708                        /*
1709                         * binary files counts bytes, not lines. Must find some
1710                         * way to normalize binary bytes vs. textual lines.
1711                         * The following heuristic assumes that there are 64
1712                         * bytes per "line".
1713                         * This is stupid and ugly, but very cheap...
1714                         */
1715                        damage = (damage + 63) / 64;
1716                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1717                dir.files[dir.nr].name = file->name;
1718                dir.files[dir.nr].changed = damage;
1719                changed += damage;
1720                dir.nr++;
1721        }
1722
1723        /* This can happen even with many files, if everything was renames */
1724        if (!changed)
1725                return;
1726
1727        /* Show all directories with more than x% of the changes */
1728        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1729        gather_dirstat(options, &dir, changed, "", 0);
1730}
1731
1732static void free_diffstat_info(struct diffstat_t *diffstat)
1733{
1734        int i;
1735        for (i = 0; i < diffstat->nr; i++) {
1736                struct diffstat_file *f = diffstat->files[i];
1737                if (f->name != f->print_name)
1738                        free(f->print_name);
1739                free(f->name);
1740                free(f->from_name);
1741                free(f);
1742        }
1743        free(diffstat->files);
1744}
1745
1746struct checkdiff_t {
1747        const char *filename;
1748        int lineno;
1749        int conflict_marker_size;
1750        struct diff_options *o;
1751        unsigned ws_rule;
1752        unsigned status;
1753};
1754
1755static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1756{
1757        char firstchar;
1758        int cnt;
1759
1760        if (len < marker_size + 1)
1761                return 0;
1762        firstchar = line[0];
1763        switch (firstchar) {
1764        case '=': case '>': case '<': case '|':
1765                break;
1766        default:
1767                return 0;
1768        }
1769        for (cnt = 1; cnt < marker_size; cnt++)
1770                if (line[cnt] != firstchar)
1771                        return 0;
1772        /* line[1] thru line[marker_size-1] are same as firstchar */
1773        if (len < marker_size + 1 || !isspace(line[marker_size]))
1774                return 0;
1775        return 1;
1776}
1777
1778static void checkdiff_consume(void *priv, char *line, unsigned long len)
1779{
1780        struct checkdiff_t *data = priv;
1781        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1782        int marker_size = data->conflict_marker_size;
1783        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1784        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1785        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1786        char *err;
1787        char *line_prefix = "";
1788        struct strbuf *msgbuf;
1789
1790        assert(data->o);
1791        if (data->o->output_prefix) {
1792                msgbuf = data->o->output_prefix(data->o,
1793                        data->o->output_prefix_data);
1794                line_prefix = msgbuf->buf;
1795        }
1796
1797        if (line[0] == '+') {
1798                unsigned bad;
1799                data->lineno++;
1800                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1801                        data->status |= 1;
1802                        fprintf(data->o->file,
1803                                "%s%s:%d: leftover conflict marker\n",
1804                                line_prefix, data->filename, data->lineno);
1805                }
1806                bad = ws_check(line + 1, len - 1, data->ws_rule);
1807                if (!bad)
1808                        return;
1809                data->status |= bad;
1810                err = whitespace_error_string(bad);
1811                fprintf(data->o->file, "%s%s:%d: %s.\n",
1812                        line_prefix, data->filename, data->lineno, err);
1813                free(err);
1814                emit_line(data->o, set, reset, line, 1);
1815                ws_check_emit(line + 1, len - 1, data->ws_rule,
1816                              data->o->file, set, reset, ws);
1817        } else if (line[0] == ' ') {
1818                data->lineno++;
1819        } else if (line[0] == '@') {
1820                char *plus = strchr(line, '+');
1821                if (plus)
1822                        data->lineno = strtol(plus, NULL, 10) - 1;
1823                else
1824                        die("invalid diff");
1825        }
1826}
1827
1828static unsigned char *deflate_it(char *data,
1829                                 unsigned long size,
1830                                 unsigned long *result_size)
1831{
1832        int bound;
1833        unsigned char *deflated;
1834        z_stream stream;
1835
1836        memset(&stream, 0, sizeof(stream));
1837        deflateInit(&stream, zlib_compression_level);
1838        bound = deflateBound(&stream, size);
1839        deflated = xmalloc(bound);
1840        stream.next_out = deflated;
1841        stream.avail_out = bound;
1842
1843        stream.next_in = (unsigned char *)data;
1844        stream.avail_in = size;
1845        while (deflate(&stream, Z_FINISH) == Z_OK)
1846                ; /* nothing */
1847        deflateEnd(&stream);
1848        *result_size = stream.total_out;
1849        return deflated;
1850}
1851
1852static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1853{
1854        void *cp;
1855        void *delta;
1856        void *deflated;
1857        void *data;
1858        unsigned long orig_size;
1859        unsigned long delta_size;
1860        unsigned long deflate_size;
1861        unsigned long data_size;
1862
1863        /* We could do deflated delta, or we could do just deflated two,
1864         * whichever is smaller.
1865         */
1866        delta = NULL;
1867        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1868        if (one->size && two->size) {
1869                delta = diff_delta(one->ptr, one->size,
1870                                   two->ptr, two->size,
1871                                   &delta_size, deflate_size);
1872                if (delta) {
1873                        void *to_free = delta;
1874                        orig_size = delta_size;
1875                        delta = deflate_it(delta, delta_size, &delta_size);
1876                        free(to_free);
1877                }
1878        }
1879
1880        if (delta && delta_size < deflate_size) {
1881                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1882                free(deflated);
1883                data = delta;
1884                data_size = delta_size;
1885        }
1886        else {
1887                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1888                free(delta);
1889                data = deflated;
1890                data_size = deflate_size;
1891        }
1892
1893        /* emit data encoded in base85 */
1894        cp = data;
1895        while (data_size) {
1896                int bytes = (52 < data_size) ? 52 : data_size;
1897                char line[70];
1898                data_size -= bytes;
1899                if (bytes <= 26)
1900                        line[0] = bytes + 'A' - 1;
1901                else
1902                        line[0] = bytes - 26 + 'a' - 1;
1903                encode_85(line + 1, cp, bytes);
1904                cp = (char *) cp + bytes;
1905                fprintf(file, "%s", prefix);
1906                fputs(line, file);
1907                fputc('\n', file);
1908        }
1909        fprintf(file, "%s\n", prefix);
1910        free(data);
1911}
1912
1913static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1914{
1915        fprintf(file, "%sGIT binary patch\n", prefix);
1916        emit_binary_diff_body(file, one, two, prefix);
1917        emit_binary_diff_body(file, two, one, prefix);
1918}
1919
1920static void diff_filespec_load_driver(struct diff_filespec *one)
1921{
1922        /* Use already-loaded driver */
1923        if (one->driver)
1924                return;
1925
1926        if (S_ISREG(one->mode))
1927                one->driver = userdiff_find_by_path(one->path);
1928
1929        /* Fallback to default settings */
1930        if (!one->driver)
1931                one->driver = userdiff_find_by_name("default");
1932}
1933
1934int diff_filespec_is_binary(struct diff_filespec *one)
1935{
1936        if (one->is_binary == -1) {
1937                diff_filespec_load_driver(one);
1938                if (one->driver->binary != -1)
1939                        one->is_binary = one->driver->binary;
1940                else {
1941                        if (!one->data && DIFF_FILE_VALID(one))
1942                                diff_populate_filespec(one, 0);
1943                        if (one->data)
1944                                one->is_binary = buffer_is_binary(one->data,
1945                                                one->size);
1946                        if (one->is_binary == -1)
1947                                one->is_binary = 0;
1948                }
1949        }
1950        return one->is_binary;
1951}
1952
1953static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1954{
1955        diff_filespec_load_driver(one);
1956        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1957}
1958
1959static const char *userdiff_word_regex(struct diff_filespec *one)
1960{
1961        diff_filespec_load_driver(one);
1962        return one->driver->word_regex;
1963}
1964
1965void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1966{
1967        if (!options->a_prefix)
1968                options->a_prefix = a;
1969        if (!options->b_prefix)
1970                options->b_prefix = b;
1971}
1972
1973struct userdiff_driver *get_textconv(struct diff_filespec *one)
1974{
1975        if (!DIFF_FILE_VALID(one))
1976                return NULL;
1977
1978        diff_filespec_load_driver(one);
1979        return userdiff_get_textconv(one->driver);
1980}
1981
1982static void builtin_diff(const char *name_a,
1983                         const char *name_b,
1984                         struct diff_filespec *one,
1985                         struct diff_filespec *two,
1986                         const char *xfrm_msg,
1987                         int must_show_header,
1988                         struct diff_options *o,
1989                         int complete_rewrite)
1990{
1991        mmfile_t mf1, mf2;
1992        const char *lbl[2];
1993        char *a_one, *b_two;
1994        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1995        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1996        const char *a_prefix, *b_prefix;
1997        struct userdiff_driver *textconv_one = NULL;
1998        struct userdiff_driver *textconv_two = NULL;
1999        struct strbuf header = STRBUF_INIT;
2000        struct strbuf *msgbuf;
2001        char *line_prefix = "";
2002
2003        if (o->output_prefix) {
2004                msgbuf = o->output_prefix(o, o->output_prefix_data);
2005                line_prefix = msgbuf->buf;
2006        }
2007
2008        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2009                        (!one->mode || S_ISGITLINK(one->mode)) &&
2010                        (!two->mode || S_ISGITLINK(two->mode))) {
2011                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2012                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2013                show_submodule_summary(o->file, one ? one->path : two->path,
2014                                one->sha1, two->sha1, two->dirty_submodule,
2015                                del, add, reset);
2016                return;
2017        }
2018
2019        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2020                textconv_one = get_textconv(one);
2021                textconv_two = get_textconv(two);
2022        }
2023
2024        diff_set_mnemonic_prefix(o, "a/", "b/");
2025        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2026                a_prefix = o->b_prefix;
2027                b_prefix = o->a_prefix;
2028        } else {
2029                a_prefix = o->a_prefix;
2030                b_prefix = o->b_prefix;
2031        }
2032
2033        /* Never use a non-valid filename anywhere if at all possible */
2034        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2035        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2036
2037        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2038        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2039        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2040        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2041        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2042        if (lbl[0][0] == '/') {
2043                /* /dev/null */
2044                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2045                if (xfrm_msg)
2046                        strbuf_addstr(&header, xfrm_msg);
2047                must_show_header = 1;
2048        }
2049        else if (lbl[1][0] == '/') {
2050                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2051                if (xfrm_msg)
2052                        strbuf_addstr(&header, xfrm_msg);
2053                must_show_header = 1;
2054        }
2055        else {
2056                if (one->mode != two->mode) {
2057                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2058                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2059                        must_show_header = 1;
2060                }
2061                if (xfrm_msg)
2062                        strbuf_addstr(&header, xfrm_msg);
2063
2064                /*
2065                 * we do not run diff between different kind
2066                 * of objects.
2067                 */
2068                if ((one->mode ^ two->mode) & S_IFMT)
2069                        goto free_ab_and_return;
2070                if (complete_rewrite &&
2071                    (textconv_one || !diff_filespec_is_binary(one)) &&
2072                    (textconv_two || !diff_filespec_is_binary(two))) {
2073                        fprintf(o->file, "%s", header.buf);
2074                        strbuf_reset(&header);
2075                        emit_rewrite_diff(name_a, name_b, one, two,
2076                                                textconv_one, textconv_two, o);
2077                        o->found_changes = 1;
2078                        goto free_ab_and_return;
2079                }
2080        }
2081
2082        if (o->irreversible_delete && lbl[1][0] == '/') {
2083                fprintf(o->file, "%s", header.buf);
2084                strbuf_reset(&header);
2085                goto free_ab_and_return;
2086        } else if (!DIFF_OPT_TST(o, TEXT) &&
2087            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2088              (!textconv_two && diff_filespec_is_binary(two)) )) {
2089                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2090                        die("unable to read files to diff");
2091                /* Quite common confusing case */
2092                if (mf1.size == mf2.size &&
2093                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2094                        if (must_show_header)
2095                                fprintf(o->file, "%s", header.buf);
2096                        goto free_ab_and_return;
2097                }
2098                fprintf(o->file, "%s", header.buf);
2099                strbuf_reset(&header);
2100                if (DIFF_OPT_TST(o, BINARY))
2101                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2102                else
2103                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2104                                line_prefix, lbl[0], lbl[1]);
2105                o->found_changes = 1;
2106        } else {
2107                /* Crazy xdl interfaces.. */
2108                const char *diffopts = getenv("GIT_DIFF_OPTS");
2109                xpparam_t xpp;
2110                xdemitconf_t xecfg;
2111                struct emit_callback ecbdata;
2112                const struct userdiff_funcname *pe;
2113
2114                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2115                        fprintf(o->file, "%s", header.buf);
2116                        strbuf_reset(&header);
2117                }
2118
2119                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2120                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2121
2122                pe = diff_funcname_pattern(one);
2123                if (!pe)
2124                        pe = diff_funcname_pattern(two);
2125
2126                memset(&xpp, 0, sizeof(xpp));
2127                memset(&xecfg, 0, sizeof(xecfg));
2128                memset(&ecbdata, 0, sizeof(ecbdata));
2129                ecbdata.label_path = lbl;
2130                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2131                ecbdata.found_changesp = &o->found_changes;
2132                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2133                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2134                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2135                ecbdata.opt = o;
2136                ecbdata.header = header.len ? &header : NULL;
2137                xpp.flags = o->xdl_opts;
2138                xecfg.ctxlen = o->context;
2139                xecfg.interhunkctxlen = o->interhunkcontext;
2140                xecfg.flags = XDL_EMIT_FUNCNAMES;
2141                if (pe)
2142                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2143                if (!diffopts)
2144                        ;
2145                else if (!prefixcmp(diffopts, "--unified="))
2146                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2147                else if (!prefixcmp(diffopts, "-u"))
2148                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2149                if (o->word_diff) {
2150                        int i;
2151
2152                        ecbdata.diff_words =
2153                                xcalloc(1, sizeof(struct diff_words_data));
2154                        ecbdata.diff_words->type = o->word_diff;
2155                        ecbdata.diff_words->opt = o;
2156                        if (!o->word_regex)
2157                                o->word_regex = userdiff_word_regex(one);
2158                        if (!o->word_regex)
2159                                o->word_regex = userdiff_word_regex(two);
2160                        if (!o->word_regex)
2161                                o->word_regex = diff_word_regex_cfg;
2162                        if (o->word_regex) {
2163                                ecbdata.diff_words->word_regex = (regex_t *)
2164                                        xmalloc(sizeof(regex_t));
2165                                if (regcomp(ecbdata.diff_words->word_regex,
2166                                                o->word_regex,
2167                                                REG_EXTENDED | REG_NEWLINE))
2168                                        die ("Invalid regular expression: %s",
2169                                                        o->word_regex);
2170                        }
2171                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2172                                if (o->word_diff == diff_words_styles[i].type) {
2173                                        ecbdata.diff_words->style =
2174                                                &diff_words_styles[i];
2175                                        break;
2176                                }
2177                        }
2178                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2179                                struct diff_words_style *st = ecbdata.diff_words->style;
2180                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2181                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2182                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2183                        }
2184                }
2185                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2186                              &xpp, &xecfg);
2187                if (o->word_diff)
2188                        free_diff_words_data(&ecbdata);
2189                if (textconv_one)
2190                        free(mf1.ptr);
2191                if (textconv_two)
2192                        free(mf2.ptr);
2193                xdiff_clear_find_func(&xecfg);
2194        }
2195
2196 free_ab_and_return:
2197        strbuf_release(&header);
2198        diff_free_filespec_data(one);
2199        diff_free_filespec_data(two);
2200        free(a_one);
2201        free(b_two);
2202        return;
2203}
2204
2205static void builtin_diffstat(const char *name_a, const char *name_b,
2206                             struct diff_filespec *one,
2207                             struct diff_filespec *two,
2208                             struct diffstat_t *diffstat,
2209                             struct diff_options *o,
2210                             int complete_rewrite)
2211{
2212        mmfile_t mf1, mf2;
2213        struct diffstat_file *data;
2214
2215        data = diffstat_add(diffstat, name_a, name_b);
2216
2217        if (!one || !two) {
2218                data->is_unmerged = 1;
2219                return;
2220        }
2221
2222        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2223                data->is_binary = 1;
2224                data->added = diff_filespec_size(two);
2225                data->deleted = diff_filespec_size(one);
2226        }
2227
2228        else if (complete_rewrite) {
2229                diff_populate_filespec(one, 0);
2230                diff_populate_filespec(two, 0);
2231                data->deleted = count_lines(one->data, one->size);
2232                data->added = count_lines(two->data, two->size);
2233        }
2234
2235        else {
2236                /* Crazy xdl interfaces.. */
2237                xpparam_t xpp;
2238                xdemitconf_t xecfg;
2239
2240                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2241                        die("unable to read files to diff");
2242
2243                memset(&xpp, 0, sizeof(xpp));
2244                memset(&xecfg, 0, sizeof(xecfg));
2245                xpp.flags = o->xdl_opts;
2246                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2247                              &xpp, &xecfg);
2248        }
2249
2250        diff_free_filespec_data(one);
2251        diff_free_filespec_data(two);
2252}
2253
2254static void builtin_checkdiff(const char *name_a, const char *name_b,
2255                              const char *attr_path,
2256                              struct diff_filespec *one,
2257                              struct diff_filespec *two,
2258                              struct diff_options *o)
2259{
2260        mmfile_t mf1, mf2;
2261        struct checkdiff_t data;
2262
2263        if (!two)
2264                return;
2265
2266        memset(&data, 0, sizeof(data));
2267        data.filename = name_b ? name_b : name_a;
2268        data.lineno = 0;
2269        data.o = o;
2270        data.ws_rule = whitespace_rule(attr_path);
2271        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2272
2273        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2274                die("unable to read files to diff");
2275
2276        /*
2277         * All the other codepaths check both sides, but not checking
2278         * the "old" side here is deliberate.  We are checking the newly
2279         * introduced changes, and as long as the "new" side is text, we
2280         * can and should check what it introduces.
2281         */
2282        if (diff_filespec_is_binary(two))
2283                goto free_and_return;
2284        else {
2285                /* Crazy xdl interfaces.. */
2286                xpparam_t xpp;
2287                xdemitconf_t xecfg;
2288
2289                memset(&xpp, 0, sizeof(xpp));
2290                memset(&xecfg, 0, sizeof(xecfg));
2291                xecfg.ctxlen = 1; /* at least one context line */
2292                xpp.flags = 0;
2293                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2294                              &xpp, &xecfg);
2295
2296                if (data.ws_rule & WS_BLANK_AT_EOF) {
2297                        struct emit_callback ecbdata;
2298                        int blank_at_eof;
2299
2300                        ecbdata.ws_rule = data.ws_rule;
2301                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2302                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2303
2304                        if (blank_at_eof) {
2305                                static char *err;
2306                                if (!err)
2307                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2308                                fprintf(o->file, "%s:%d: %s.\n",
2309                                        data.filename, blank_at_eof, err);
2310                                data.status = 1; /* report errors */
2311                        }
2312                }
2313        }
2314 free_and_return:
2315        diff_free_filespec_data(one);
2316        diff_free_filespec_data(two);
2317        if (data.status)
2318                DIFF_OPT_SET(o, CHECK_FAILED);
2319}
2320
2321struct diff_filespec *alloc_filespec(const char *path)
2322{
2323        int namelen = strlen(path);
2324        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2325
2326        memset(spec, 0, sizeof(*spec));
2327        spec->path = (char *)(spec + 1);
2328        memcpy(spec->path, path, namelen+1);
2329        spec->count = 1;
2330        spec->is_binary = -1;
2331        return spec;
2332}
2333
2334void free_filespec(struct diff_filespec *spec)
2335{
2336        if (!--spec->count) {
2337                diff_free_filespec_data(spec);
2338                free(spec);
2339        }
2340}
2341
2342void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2343                   unsigned short mode)
2344{
2345        if (mode) {
2346                spec->mode = canon_mode(mode);
2347                hashcpy(spec->sha1, sha1);
2348                spec->sha1_valid = !is_null_sha1(sha1);
2349        }
2350}
2351
2352/*
2353 * Given a name and sha1 pair, if the index tells us the file in
2354 * the work tree has that object contents, return true, so that
2355 * prepare_temp_file() does not have to inflate and extract.
2356 */
2357static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2358{
2359        struct cache_entry *ce;
2360        struct stat st;
2361        int pos, len;
2362
2363        /*
2364         * We do not read the cache ourselves here, because the
2365         * benchmark with my previous version that always reads cache
2366         * shows that it makes things worse for diff-tree comparing
2367         * two linux-2.6 kernel trees in an already checked out work
2368         * tree.  This is because most diff-tree comparisons deal with
2369         * only a small number of files, while reading the cache is
2370         * expensive for a large project, and its cost outweighs the
2371         * savings we get by not inflating the object to a temporary
2372         * file.  Practically, this code only helps when we are used
2373         * by diff-cache --cached, which does read the cache before
2374         * calling us.
2375         */
2376        if (!active_cache)
2377                return 0;
2378
2379        /* We want to avoid the working directory if our caller
2380         * doesn't need the data in a normal file, this system
2381         * is rather slow with its stat/open/mmap/close syscalls,
2382         * and the object is contained in a pack file.  The pack
2383         * is probably already open and will be faster to obtain
2384         * the data through than the working directory.  Loose
2385         * objects however would tend to be slower as they need
2386         * to be individually opened and inflated.
2387         */
2388        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2389                return 0;
2390
2391        len = strlen(name);
2392        pos = cache_name_pos(name, len);
2393        if (pos < 0)
2394                return 0;
2395        ce = active_cache[pos];
2396
2397        /*
2398         * This is not the sha1 we are looking for, or
2399         * unreusable because it is not a regular file.
2400         */
2401        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2402                return 0;
2403
2404        /*
2405         * If ce is marked as "assume unchanged", there is no
2406         * guarantee that work tree matches what we are looking for.
2407         */
2408        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2409                return 0;
2410
2411        /*
2412         * If ce matches the file in the work tree, we can reuse it.
2413         */
2414        if (ce_uptodate(ce) ||
2415            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2416                return 1;
2417
2418        return 0;
2419}
2420
2421static int populate_from_stdin(struct diff_filespec *s)
2422{
2423        struct strbuf buf = STRBUF_INIT;
2424        size_t size = 0;
2425
2426        if (strbuf_read(&buf, 0, 0) < 0)
2427                return error("error while reading from stdin %s",
2428                                     strerror(errno));
2429
2430        s->should_munmap = 0;
2431        s->data = strbuf_detach(&buf, &size);
2432        s->size = size;
2433        s->should_free = 1;
2434        return 0;
2435}
2436
2437static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2438{
2439        int len;
2440        char *data = xmalloc(100), *dirty = "";
2441
2442        /* Are we looking at the work tree? */
2443        if (s->dirty_submodule)
2444                dirty = "-dirty";
2445
2446        len = snprintf(data, 100,
2447                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2448        s->data = data;
2449        s->size = len;
2450        s->should_free = 1;
2451        if (size_only) {
2452                s->data = NULL;
2453                free(data);
2454        }
2455        return 0;
2456}
2457
2458/*
2459 * While doing rename detection and pickaxe operation, we may need to
2460 * grab the data for the blob (or file) for our own in-core comparison.
2461 * diff_filespec has data and size fields for this purpose.
2462 */
2463int diff_populate_filespec(struct diff_filespec *s, int size_only)
2464{
2465        int err = 0;
2466        if (!DIFF_FILE_VALID(s))
2467                die("internal error: asking to populate invalid file.");
2468        if (S_ISDIR(s->mode))
2469                return -1;
2470
2471        if (s->data)
2472                return 0;
2473
2474        if (size_only && 0 < s->size)
2475                return 0;
2476
2477        if (S_ISGITLINK(s->mode))
2478                return diff_populate_gitlink(s, size_only);
2479
2480        if (!s->sha1_valid ||
2481            reuse_worktree_file(s->path, s->sha1, 0)) {
2482                struct strbuf buf = STRBUF_INIT;
2483                struct stat st;
2484                int fd;
2485
2486                if (!strcmp(s->path, "-"))
2487                        return populate_from_stdin(s);
2488
2489                if (lstat(s->path, &st) < 0) {
2490                        if (errno == ENOENT) {
2491                        err_empty:
2492                                err = -1;
2493                        empty:
2494                                s->data = (char *)"";
2495                                s->size = 0;
2496                                return err;
2497                        }
2498                }
2499                s->size = xsize_t(st.st_size);
2500                if (!s->size)
2501                        goto empty;
2502                if (S_ISLNK(st.st_mode)) {
2503                        struct strbuf sb = STRBUF_INIT;
2504
2505                        if (strbuf_readlink(&sb, s->path, s->size))
2506                                goto err_empty;
2507                        s->size = sb.len;
2508                        s->data = strbuf_detach(&sb, NULL);
2509                        s->should_free = 1;
2510                        return 0;
2511                }
2512                if (size_only)
2513                        return 0;
2514                fd = open(s->path, O_RDONLY);
2515                if (fd < 0)
2516                        goto err_empty;
2517                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2518                close(fd);
2519                s->should_munmap = 1;
2520
2521                /*
2522                 * Convert from working tree format to canonical git format
2523                 */
2524                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2525                        size_t size = 0;
2526                        munmap(s->data, s->size);
2527                        s->should_munmap = 0;
2528                        s->data = strbuf_detach(&buf, &size);
2529                        s->size = size;
2530                        s->should_free = 1;
2531                }
2532        }
2533        else {
2534                enum object_type type;
2535                if (size_only) {
2536                        type = sha1_object_info(s->sha1, &s->size);
2537                        if (type < 0)
2538                                die("unable to read %s", sha1_to_hex(s->sha1));
2539                } else {
2540                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2541                        if (!s->data)
2542                                die("unable to read %s", sha1_to_hex(s->sha1));
2543                        s->should_free = 1;
2544                }
2545        }
2546        return 0;
2547}
2548
2549void diff_free_filespec_blob(struct diff_filespec *s)
2550{
2551        if (s->should_free)
2552                free(s->data);
2553        else if (s->should_munmap)
2554                munmap(s->data, s->size);
2555
2556        if (s->should_free || s->should_munmap) {
2557                s->should_free = s->should_munmap = 0;
2558                s->data = NULL;
2559        }
2560}
2561
2562void diff_free_filespec_data(struct diff_filespec *s)
2563{
2564        diff_free_filespec_blob(s);
2565        free(s->cnt_data);
2566        s->cnt_data = NULL;
2567}
2568
2569static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2570                           void *blob,
2571                           unsigned long size,
2572                           const unsigned char *sha1,
2573                           int mode)
2574{
2575        int fd;
2576        struct strbuf buf = STRBUF_INIT;
2577        struct strbuf template = STRBUF_INIT;
2578        char *path_dup = xstrdup(path);
2579        const char *base = basename(path_dup);
2580
2581        /* Generate "XXXXXX_basename.ext" */
2582        strbuf_addstr(&template, "XXXXXX_");
2583        strbuf_addstr(&template, base);
2584
2585        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2586                        strlen(base) + 1);
2587        if (fd < 0)
2588                die_errno("unable to create temp-file");
2589        if (convert_to_working_tree(path,
2590                        (const char *)blob, (size_t)size, &buf)) {
2591                blob = buf.buf;
2592                size = buf.len;
2593        }
2594        if (write_in_full(fd, blob, size) != size)
2595                die_errno("unable to write temp-file");
2596        close(fd);
2597        temp->name = temp->tmp_path;
2598        strcpy(temp->hex, sha1_to_hex(sha1));
2599        temp->hex[40] = 0;
2600        sprintf(temp->mode, "%06o", mode);
2601        strbuf_release(&buf);
2602        strbuf_release(&template);
2603        free(path_dup);
2604}
2605
2606static struct diff_tempfile *prepare_temp_file(const char *name,
2607                struct diff_filespec *one)
2608{
2609        struct diff_tempfile *temp = claim_diff_tempfile();
2610
2611        if (!DIFF_FILE_VALID(one)) {
2612        not_a_valid_file:
2613                /* A '-' entry produces this for file-2, and
2614                 * a '+' entry produces this for file-1.
2615                 */
2616                temp->name = "/dev/null";
2617                strcpy(temp->hex, ".");
2618                strcpy(temp->mode, ".");
2619                return temp;
2620        }
2621
2622        if (!remove_tempfile_installed) {
2623                atexit(remove_tempfile);
2624                sigchain_push_common(remove_tempfile_on_signal);
2625                remove_tempfile_installed = 1;
2626        }
2627
2628        if (!one->sha1_valid ||
2629            reuse_worktree_file(name, one->sha1, 1)) {
2630                struct stat st;
2631                if (lstat(name, &st) < 0) {
2632                        if (errno == ENOENT)
2633                                goto not_a_valid_file;
2634                        die_errno("stat(%s)", name);
2635                }
2636                if (S_ISLNK(st.st_mode)) {
2637                        struct strbuf sb = STRBUF_INIT;
2638                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2639                                die_errno("readlink(%s)", name);
2640                        prep_temp_blob(name, temp, sb.buf, sb.len,
2641                                       (one->sha1_valid ?
2642                                        one->sha1 : null_sha1),
2643                                       (one->sha1_valid ?
2644                                        one->mode : S_IFLNK));
2645                        strbuf_release(&sb);
2646                }
2647                else {
2648                        /* we can borrow from the file in the work tree */
2649                        temp->name = name;
2650                        if (!one->sha1_valid)
2651                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2652                        else
2653                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2654                        /* Even though we may sometimes borrow the
2655                         * contents from the work tree, we always want
2656                         * one->mode.  mode is trustworthy even when
2657                         * !(one->sha1_valid), as long as
2658                         * DIFF_FILE_VALID(one).
2659                         */
2660                        sprintf(temp->mode, "%06o", one->mode);
2661                }
2662                return temp;
2663        }
2664        else {
2665                if (diff_populate_filespec(one, 0))
2666                        die("cannot read data blob for %s", one->path);
2667                prep_temp_blob(name, temp, one->data, one->size,
2668                               one->sha1, one->mode);
2669        }
2670        return temp;
2671}
2672
2673/* An external diff command takes:
2674 *
2675 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2676 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2677 *
2678 */
2679static void run_external_diff(const char *pgm,
2680                              const char *name,
2681                              const char *other,
2682                              struct diff_filespec *one,
2683                              struct diff_filespec *two,
2684                              const char *xfrm_msg,
2685                              int complete_rewrite)
2686{
2687        const char *spawn_arg[10];
2688        int retval;
2689        const char **arg = &spawn_arg[0];
2690
2691        if (one && two) {
2692                struct diff_tempfile *temp_one, *temp_two;
2693                const char *othername = (other ? other : name);
2694                temp_one = prepare_temp_file(name, one);
2695                temp_two = prepare_temp_file(othername, two);
2696                *arg++ = pgm;
2697                *arg++ = name;
2698                *arg++ = temp_one->name;
2699                *arg++ = temp_one->hex;
2700                *arg++ = temp_one->mode;
2701                *arg++ = temp_two->name;
2702                *arg++ = temp_two->hex;
2703                *arg++ = temp_two->mode;
2704                if (other) {
2705                        *arg++ = other;
2706                        *arg++ = xfrm_msg;
2707                }
2708        } else {
2709                *arg++ = pgm;
2710                *arg++ = name;
2711        }
2712        *arg = NULL;
2713        fflush(NULL);
2714        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2715        remove_tempfile();
2716        if (retval) {
2717                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2718                exit(1);
2719        }
2720}
2721
2722static int similarity_index(struct diff_filepair *p)
2723{
2724        return p->score * 100 / MAX_SCORE;
2725}
2726
2727static void fill_metainfo(struct strbuf *msg,
2728                          const char *name,
2729                          const char *other,
2730                          struct diff_filespec *one,
2731                          struct diff_filespec *two,
2732                          struct diff_options *o,
2733                          struct diff_filepair *p,
2734                          int *must_show_header,
2735                          int use_color)
2736{
2737        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2738        const char *reset = diff_get_color(use_color, DIFF_RESET);
2739        struct strbuf *msgbuf;
2740        char *line_prefix = "";
2741
2742        *must_show_header = 1;
2743        if (o->output_prefix) {
2744                msgbuf = o->output_prefix(o, o->output_prefix_data);
2745                line_prefix = msgbuf->buf;
2746        }
2747        strbuf_init(msg, PATH_MAX * 2 + 300);
2748        switch (p->status) {
2749        case DIFF_STATUS_COPIED:
2750                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2751                            line_prefix, set, similarity_index(p));
2752                strbuf_addf(msg, "%s\n%s%scopy from ",
2753                            reset,  line_prefix, set);
2754                quote_c_style(name, msg, NULL, 0);
2755                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2756                quote_c_style(other, msg, NULL, 0);
2757                strbuf_addf(msg, "%s\n", reset);
2758                break;
2759        case DIFF_STATUS_RENAMED:
2760                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2761                            line_prefix, set, similarity_index(p));
2762                strbuf_addf(msg, "%s\n%s%srename from ",
2763                            reset, line_prefix, set);
2764                quote_c_style(name, msg, NULL, 0);
2765                strbuf_addf(msg, "%s\n%s%srename to ",
2766                            reset, line_prefix, set);
2767                quote_c_style(other, msg, NULL, 0);
2768                strbuf_addf(msg, "%s\n", reset);
2769                break;
2770        case DIFF_STATUS_MODIFIED:
2771                if (p->score) {
2772                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2773                                    line_prefix,
2774                                    set, similarity_index(p), reset);
2775                        break;
2776                }
2777                /* fallthru */
2778        default:
2779                *must_show_header = 0;
2780        }
2781        if (one && two && hashcmp(one->sha1, two->sha1)) {
2782                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2783
2784                if (DIFF_OPT_TST(o, BINARY)) {
2785                        mmfile_t mf;
2786                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2787                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2788                                abbrev = 40;
2789                }
2790                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2791                            find_unique_abbrev(one->sha1, abbrev));
2792                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2793                if (one->mode == two->mode)
2794                        strbuf_addf(msg, " %06o", one->mode);
2795                strbuf_addf(msg, "%s\n", reset);
2796        }
2797}
2798
2799static void run_diff_cmd(const char *pgm,
2800                         const char *name,
2801                         const char *other,
2802                         const char *attr_path,
2803                         struct diff_filespec *one,
2804                         struct diff_filespec *two,
2805                         struct strbuf *msg,
2806                         struct diff_options *o,
2807                         struct diff_filepair *p)
2808{
2809        const char *xfrm_msg = NULL;
2810        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2811        int must_show_header = 0;
2812
2813        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2814                pgm = NULL;
2815        else {
2816                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2817                if (drv && drv->external)
2818                        pgm = drv->external;
2819        }
2820
2821        if (msg) {
2822                /*
2823                 * don't use colors when the header is intended for an
2824                 * external diff driver
2825                 */
2826                fill_metainfo(msg, name, other, one, two, o, p,
2827                              &must_show_header,
2828                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2829                xfrm_msg = msg->len ? msg->buf : NULL;
2830        }
2831
2832        if (pgm) {
2833                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2834                                  complete_rewrite);
2835                return;
2836        }
2837        if (one && two)
2838                builtin_diff(name, other ? other : name,
2839                             one, two, xfrm_msg, must_show_header,
2840                             o, complete_rewrite);
2841        else
2842                fprintf(o->file, "* Unmerged path %s\n", name);
2843}
2844
2845static void diff_fill_sha1_info(struct diff_filespec *one)
2846{
2847        if (DIFF_FILE_VALID(one)) {
2848                if (!one->sha1_valid) {
2849                        struct stat st;
2850                        if (!strcmp(one->path, "-")) {
2851                                hashcpy(one->sha1, null_sha1);
2852                                return;
2853                        }
2854                        if (lstat(one->path, &st) < 0)
2855                                die_errno("stat '%s'", one->path);
2856                        if (index_path(one->sha1, one->path, &st, 0))
2857                                die("cannot hash %s", one->path);
2858                }
2859        }
2860        else
2861                hashclr(one->sha1);
2862}
2863
2864static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2865{
2866        /* Strip the prefix but do not molest /dev/null and absolute paths */
2867        if (*namep && **namep != '/') {
2868                *namep += prefix_length;
2869                if (**namep == '/')
2870                        ++*namep;
2871        }
2872        if (*otherp && **otherp != '/') {
2873                *otherp += prefix_length;
2874                if (**otherp == '/')
2875                        ++*otherp;
2876        }
2877}
2878
2879static void run_diff(struct diff_filepair *p, struct diff_options *o)
2880{
2881        const char *pgm = external_diff();
2882        struct strbuf msg;
2883        struct diff_filespec *one = p->one;
2884        struct diff_filespec *two = p->two;
2885        const char *name;
2886        const char *other;
2887        const char *attr_path;
2888
2889        name  = p->one->path;
2890        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2891        attr_path = name;
2892        if (o->prefix_length)
2893                strip_prefix(o->prefix_length, &name, &other);
2894
2895        if (DIFF_PAIR_UNMERGED(p)) {
2896                run_diff_cmd(pgm, name, NULL, attr_path,
2897                             NULL, NULL, NULL, o, p);
2898                return;
2899        }
2900
2901        diff_fill_sha1_info(one);
2902        diff_fill_sha1_info(two);
2903
2904        if (!pgm &&
2905            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2906            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2907                /*
2908                 * a filepair that changes between file and symlink
2909                 * needs to be split into deletion and creation.
2910                 */
2911                struct diff_filespec *null = alloc_filespec(two->path);
2912                run_diff_cmd(NULL, name, other, attr_path,
2913                             one, null, &msg, o, p);
2914                free(null);
2915                strbuf_release(&msg);
2916
2917                null = alloc_filespec(one->path);
2918                run_diff_cmd(NULL, name, other, attr_path,
2919                             null, two, &msg, o, p);
2920                free(null);
2921        }
2922        else
2923                run_diff_cmd(pgm, name, other, attr_path,
2924                             one, two, &msg, o, p);
2925
2926        strbuf_release(&msg);
2927}
2928
2929static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2930                         struct diffstat_t *diffstat)
2931{
2932        const char *name;
2933        const char *other;
2934        int complete_rewrite = 0;
2935
2936        if (DIFF_PAIR_UNMERGED(p)) {
2937                /* unmerged */
2938                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2939                return;
2940        }
2941
2942        name = p->one->path;
2943        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2944
2945        if (o->prefix_length)
2946                strip_prefix(o->prefix_length, &name, &other);
2947
2948        diff_fill_sha1_info(p->one);
2949        diff_fill_sha1_info(p->two);
2950
2951        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2952                complete_rewrite = 1;
2953        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2954}
2955
2956static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2957{
2958        const char *name;
2959        const char *other;
2960        const char *attr_path;
2961
2962        if (DIFF_PAIR_UNMERGED(p)) {
2963                /* unmerged */
2964                return;
2965        }
2966
2967        name = p->one->path;
2968        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2969        attr_path = other ? other : name;
2970
2971        if (o->prefix_length)
2972                strip_prefix(o->prefix_length, &name, &other);
2973
2974        diff_fill_sha1_info(p->one);
2975        diff_fill_sha1_info(p->two);
2976
2977        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2978}
2979
2980void diff_setup(struct diff_options *options)
2981{
2982        memcpy(options, &default_diff_options, sizeof(*options));
2983
2984        options->file = stdout;
2985
2986        options->line_termination = '\n';
2987        options->break_opt = -1;
2988        options->rename_limit = -1;
2989        options->dirstat_permille = diff_dirstat_permille_default;
2990        options->context = 3;
2991
2992        options->change = diff_change;
2993        options->add_remove = diff_addremove;
2994        if (diff_use_color_default > 0)
2995                DIFF_OPT_SET(options, COLOR_DIFF);
2996        options->detect_rename = diff_detect_rename_default;
2997
2998        if (diff_no_prefix) {
2999                options->a_prefix = options->b_prefix = "";
3000        } else if (!diff_mnemonic_prefix) {
3001                options->a_prefix = "a/";
3002                options->b_prefix = "b/";
3003        }
3004}
3005
3006int diff_setup_done(struct diff_options *options)
3007{
3008        int count = 0;
3009
3010        if (options->output_format & DIFF_FORMAT_NAME)
3011                count++;
3012        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3013                count++;
3014        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3015                count++;
3016        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3017                count++;
3018        if (count > 1)
3019                die("--name-only, --name-status, --check and -s are mutually exclusive");
3020
3021        /*
3022         * Most of the time we can say "there are changes"
3023         * only by checking if there are changed paths, but
3024         * --ignore-whitespace* options force us to look
3025         * inside contents.
3026         */
3027
3028        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3029            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3030            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3031                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3032        else
3033                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3034
3035        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3036                options->detect_rename = DIFF_DETECT_COPY;
3037
3038        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3039                options->prefix = NULL;
3040        if (options->prefix)
3041                options->prefix_length = strlen(options->prefix);
3042        else
3043                options->prefix_length = 0;
3044
3045        if (options->output_format & (DIFF_FORMAT_NAME |
3046                                      DIFF_FORMAT_NAME_STATUS |
3047                                      DIFF_FORMAT_CHECKDIFF |
3048                                      DIFF_FORMAT_NO_OUTPUT))
3049                options->output_format &= ~(DIFF_FORMAT_RAW |
3050                                            DIFF_FORMAT_NUMSTAT |
3051                                            DIFF_FORMAT_DIFFSTAT |
3052                                            DIFF_FORMAT_SHORTSTAT |
3053                                            DIFF_FORMAT_DIRSTAT |
3054                                            DIFF_FORMAT_SUMMARY |
3055                                            DIFF_FORMAT_PATCH);
3056
3057        /*
3058         * These cases always need recursive; we do not drop caller-supplied
3059         * recursive bits for other formats here.
3060         */
3061        if (options->output_format & (DIFF_FORMAT_PATCH |
3062                                      DIFF_FORMAT_NUMSTAT |
3063                                      DIFF_FORMAT_DIFFSTAT |
3064                                      DIFF_FORMAT_SHORTSTAT |
3065                                      DIFF_FORMAT_DIRSTAT |
3066                                      DIFF_FORMAT_SUMMARY |
3067                                      DIFF_FORMAT_CHECKDIFF))
3068                DIFF_OPT_SET(options, RECURSIVE);
3069        /*
3070         * Also pickaxe would not work very well if you do not say recursive
3071         */
3072        if (options->pickaxe)
3073                DIFF_OPT_SET(options, RECURSIVE);
3074        /*
3075         * When patches are generated, submodules diffed against the work tree
3076         * must be checked for dirtiness too so it can be shown in the output
3077         */
3078        if (options->output_format & DIFF_FORMAT_PATCH)
3079                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3080
3081        if (options->detect_rename && options->rename_limit < 0)
3082                options->rename_limit = diff_rename_limit_default;
3083        if (options->setup & DIFF_SETUP_USE_CACHE) {
3084                if (!active_cache)
3085                        /* read-cache does not die even when it fails
3086                         * so it is safe for us to do this here.  Also
3087                         * it does not smudge active_cache or active_nr
3088                         * when it fails, so we do not have to worry about
3089                         * cleaning it up ourselves either.
3090                         */
3091                        read_cache();
3092        }
3093        if (options->abbrev <= 0 || 40 < options->abbrev)
3094                options->abbrev = 40; /* full */
3095
3096        /*
3097         * It does not make sense to show the first hit we happened
3098         * to have found.  It does not make sense not to return with
3099         * exit code in such a case either.
3100         */
3101        if (DIFF_OPT_TST(options, QUICK)) {
3102                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3103                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3104        }
3105
3106        return 0;
3107}
3108
3109static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3110{
3111        char c, *eq;
3112        int len;
3113
3114        if (*arg != '-')
3115                return 0;
3116        c = *++arg;
3117        if (!c)
3118                return 0;
3119        if (c == arg_short) {
3120                c = *++arg;
3121                if (!c)
3122                        return 1;
3123                if (val && isdigit(c)) {
3124                        char *end;
3125                        int n = strtoul(arg, &end, 10);
3126                        if (*end)
3127                                return 0;
3128                        *val = n;
3129                        return 1;
3130                }
3131                return 0;
3132        }
3133        if (c != '-')
3134                return 0;
3135        arg++;
3136        eq = strchr(arg, '=');
3137        if (eq)
3138                len = eq - arg;
3139        else
3140                len = strlen(arg);
3141        if (!len || strncmp(arg, arg_long, len))
3142                return 0;
3143        if (eq) {
3144                int n;
3145                char *end;
3146                if (!isdigit(*++eq))
3147                        return 0;
3148                n = strtoul(eq, &end, 10);
3149                if (*end)
3150                        return 0;
3151                *val = n;
3152        }
3153        return 1;
3154}
3155
3156static int diff_scoreopt_parse(const char *opt);
3157
3158static inline int short_opt(char opt, const char **argv,
3159                            const char **optarg)
3160{
3161        const char *arg = argv[0];
3162        if (arg[0] != '-' || arg[1] != opt)
3163                return 0;
3164        if (arg[2] != '\0') {
3165                *optarg = arg + 2;
3166                return 1;
3167        }
3168        if (!argv[1])
3169                die("Option '%c' requires a value", opt);
3170        *optarg = argv[1];
3171        return 2;
3172}
3173
3174int parse_long_opt(const char *opt, const char **argv,
3175                   const char **optarg)
3176{
3177        const char *arg = argv[0];
3178        if (arg[0] != '-' || arg[1] != '-')
3179                return 0;
3180        arg += strlen("--");
3181        if (prefixcmp(arg, opt))
3182                return 0;
3183        arg += strlen(opt);
3184        if (*arg == '=') { /* sticked form: --option=value */
3185                *optarg = arg + 1;
3186                return 1;
3187        }
3188        if (*arg != '\0')
3189                return 0;
3190        /* separate form: --option value */
3191        if (!argv[1])
3192                die("Option '--%s' requires a value", opt);
3193        *optarg = argv[1];
3194        return 2;
3195}
3196
3197static int stat_opt(struct diff_options *options, const char **av)
3198{
3199        const char *arg = av[0];
3200        char *end;
3201        int width = options->stat_width;
3202        int name_width = options->stat_name_width;
3203        int argcount = 1;
3204
3205        arg += strlen("--stat");
3206        end = (char *)arg;
3207
3208        switch (*arg) {
3209        case '-':
3210                if (!prefixcmp(arg, "-width")) {
3211                        arg += strlen("-width");
3212                        if (*arg == '=')
3213                                width = strtoul(arg + 1, &end, 10);
3214                        else if (!*arg && !av[1])
3215                                die("Option '--stat-width' requires a value");
3216                        else if (!*arg) {
3217                                width = strtoul(av[1], &end, 10);
3218                                argcount = 2;
3219                        }
3220                } else if (!prefixcmp(arg, "-name-width")) {
3221                        arg += strlen("-name-width");
3222                        if (*arg == '=')
3223                                name_width = strtoul(arg + 1, &end, 10);
3224                        else if (!*arg && !av[1])
3225                                die("Option '--stat-name-width' requires a value");
3226                        else if (!*arg) {
3227                                name_width = strtoul(av[1], &end, 10);
3228                                argcount = 2;
3229                        }
3230                }
3231                break;
3232        case '=':
3233                width = strtoul(arg+1, &end, 10);
3234                if (*end == ',')
3235                        name_width = strtoul(end+1, &end, 10);
3236        }
3237
3238        /* Important! This checks all the error cases! */
3239        if (*end)
3240                return 0;
3241        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3242        options->stat_name_width = name_width;
3243        options->stat_width = width;
3244        return argcount;
3245}
3246
3247static int parse_dirstat_opt(struct diff_options *options, const char *params)
3248{
3249        struct strbuf errmsg = STRBUF_INIT;
3250        if (parse_dirstat_params(options, params, &errmsg))
3251                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3252                    errmsg.buf);
3253        strbuf_release(&errmsg);
3254        /*
3255         * The caller knows a dirstat-related option is given from the command
3256         * line; allow it to say "return this_function();"
3257         */
3258        options->output_format |= DIFF_FORMAT_DIRSTAT;
3259        return 1;
3260}
3261
3262int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3263{
3264        const char *arg = av[0];
3265        const char *optarg;
3266        int argcount;
3267
3268        /* Output format options */
3269        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3270                options->output_format |= DIFF_FORMAT_PATCH;
3271        else if (opt_arg(arg, 'U', "unified", &options->context))
3272                options->output_format |= DIFF_FORMAT_PATCH;
3273        else if (!strcmp(arg, "--raw"))
3274                options->output_format |= DIFF_FORMAT_RAW;
3275        else if (!strcmp(arg, "--patch-with-raw"))
3276                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3277        else if (!strcmp(arg, "--numstat"))
3278                options->output_format |= DIFF_FORMAT_NUMSTAT;
3279        else if (!strcmp(arg, "--shortstat"))
3280                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3281        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3282                return parse_dirstat_opt(options, "");
3283        else if (!prefixcmp(arg, "-X"))
3284                return parse_dirstat_opt(options, arg + 2);
3285        else if (!prefixcmp(arg, "--dirstat="))
3286                return parse_dirstat_opt(options, arg + 10);
3287        else if (!strcmp(arg, "--cumulative"))
3288                return parse_dirstat_opt(options, "cumulative");
3289        else if (!strcmp(arg, "--dirstat-by-file"))
3290                return parse_dirstat_opt(options, "files");
3291        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3292                parse_dirstat_opt(options, "files");
3293                return parse_dirstat_opt(options, arg + 18);
3294        }
3295        else if (!strcmp(arg, "--check"))
3296                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3297        else if (!strcmp(arg, "--summary"))
3298                options->output_format |= DIFF_FORMAT_SUMMARY;
3299        else if (!strcmp(arg, "--patch-with-stat"))
3300                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3301        else if (!strcmp(arg, "--name-only"))
3302                options->output_format |= DIFF_FORMAT_NAME;
3303        else if (!strcmp(arg, "--name-status"))
3304                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3305        else if (!strcmp(arg, "-s"))
3306                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3307        else if (!prefixcmp(arg, "--stat"))
3308                /* --stat, --stat-width, or --stat-name-width */
3309                return stat_opt(options, av);
3310
3311        /* renames options */
3312        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3313                 !strcmp(arg, "--break-rewrites")) {
3314                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3315                        return error("invalid argument to -B: %s", arg+2);
3316        }
3317        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3318                 !strcmp(arg, "--find-renames")) {
3319                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3320                        return error("invalid argument to -M: %s", arg+2);
3321                options->detect_rename = DIFF_DETECT_RENAME;
3322        }
3323        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3324                options->irreversible_delete = 1;
3325        }
3326        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3327                 !strcmp(arg, "--find-copies")) {
3328                if (options->detect_rename == DIFF_DETECT_COPY)
3329                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3330                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3331                        return error("invalid argument to -C: %s", arg+2);
3332                options->detect_rename = DIFF_DETECT_COPY;
3333        }
3334        else if (!strcmp(arg, "--no-renames"))
3335                options->detect_rename = 0;
3336        else if (!strcmp(arg, "--relative"))
3337                DIFF_OPT_SET(options, RELATIVE_NAME);
3338        else if (!prefixcmp(arg, "--relative=")) {
3339                DIFF_OPT_SET(options, RELATIVE_NAME);
3340                options->prefix = arg + 11;
3341        }
3342
3343        /* xdiff options */
3344        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3345                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3346        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3347                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3348        else if (!strcmp(arg, "--ignore-space-at-eol"))
3349                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3350        else if (!strcmp(arg, "--patience"))
3351                DIFF_XDL_SET(options, PATIENCE_DIFF);
3352
3353        /* flags options */
3354        else if (!strcmp(arg, "--binary")) {
3355                options->output_format |= DIFF_FORMAT_PATCH;
3356                DIFF_OPT_SET(options, BINARY);
3357        }
3358        else if (!strcmp(arg, "--full-index"))
3359                DIFF_OPT_SET(options, FULL_INDEX);
3360        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3361                DIFF_OPT_SET(options, TEXT);
3362        else if (!strcmp(arg, "-R"))
3363                DIFF_OPT_SET(options, REVERSE_DIFF);
3364        else if (!strcmp(arg, "--find-copies-harder"))
3365                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3366        else if (!strcmp(arg, "--follow"))
3367                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3368        else if (!strcmp(arg, "--color"))
3369                DIFF_OPT_SET(options, COLOR_DIFF);
3370        else if (!prefixcmp(arg, "--color=")) {
3371                int value = git_config_colorbool(NULL, arg+8, -1);
3372                if (value == 0)
3373                        DIFF_OPT_CLR(options, COLOR_DIFF);
3374                else if (value > 0)
3375                        DIFF_OPT_SET(options, COLOR_DIFF);
3376                else
3377                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3378        }
3379        else if (!strcmp(arg, "--no-color"))
3380                DIFF_OPT_CLR(options, COLOR_DIFF);
3381        else if (!strcmp(arg, "--color-words")) {
3382                DIFF_OPT_SET(options, COLOR_DIFF);
3383                options->word_diff = DIFF_WORDS_COLOR;
3384        }
3385        else if (!prefixcmp(arg, "--color-words=")) {
3386                DIFF_OPT_SET(options, COLOR_DIFF);
3387                options->word_diff = DIFF_WORDS_COLOR;
3388                options->word_regex = arg + 14;
3389        }
3390        else if (!strcmp(arg, "--word-diff")) {
3391                if (options->word_diff == DIFF_WORDS_NONE)
3392                        options->word_diff = DIFF_WORDS_PLAIN;
3393        }
3394        else if (!prefixcmp(arg, "--word-diff=")) {
3395                const char *type = arg + 12;
3396                if (!strcmp(type, "plain"))
3397                        options->word_diff = DIFF_WORDS_PLAIN;
3398                else if (!strcmp(type, "color")) {
3399                        DIFF_OPT_SET(options, COLOR_DIFF);
3400                        options->word_diff = DIFF_WORDS_COLOR;
3401                }
3402                else if (!strcmp(type, "porcelain"))
3403                        options->word_diff = DIFF_WORDS_PORCELAIN;
3404                else if (!strcmp(type, "none"))
3405                        options->word_diff = DIFF_WORDS_NONE;
3406                else
3407                        die("bad --word-diff argument: %s", type);
3408        }
3409        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3410                if (options->word_diff == DIFF_WORDS_NONE)
3411                        options->word_diff = DIFF_WORDS_PLAIN;
3412                options->word_regex = optarg;
3413                return argcount;
3414        }
3415        else if (!strcmp(arg, "--exit-code"))
3416                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3417        else if (!strcmp(arg, "--quiet"))
3418                DIFF_OPT_SET(options, QUICK);
3419        else if (!strcmp(arg, "--ext-diff"))
3420                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3421        else if (!strcmp(arg, "--no-ext-diff"))
3422                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3423        else if (!strcmp(arg, "--textconv"))
3424                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3425        else if (!strcmp(arg, "--no-textconv"))
3426                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3427        else if (!strcmp(arg, "--ignore-submodules")) {
3428                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3429                handle_ignore_submodules_arg(options, "all");
3430        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3431                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3432                handle_ignore_submodules_arg(options, arg + 20);
3433        } else if (!strcmp(arg, "--submodule"))
3434                DIFF_OPT_SET(options, SUBMODULE_LOG);
3435        else if (!prefixcmp(arg, "--submodule=")) {
3436                if (!strcmp(arg + 12, "log"))
3437                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3438        }
3439
3440        /* misc options */
3441        else if (!strcmp(arg, "-z"))
3442                options->line_termination = 0;
3443        else if ((argcount = short_opt('l', av, &optarg))) {
3444                options->rename_limit = strtoul(optarg, NULL, 10);
3445                return argcount;
3446        }
3447        else if ((argcount = short_opt('S', av, &optarg))) {
3448                options->pickaxe = optarg;
3449                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3450                return argcount;
3451        } else if ((argcount = short_opt('G', av, &optarg))) {
3452                options->pickaxe = optarg;
3453                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3454                return argcount;
3455        }
3456        else if (!strcmp(arg, "--pickaxe-all"))
3457                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3458        else if (!strcmp(arg, "--pickaxe-regex"))
3459                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3460        else if ((argcount = short_opt('O', av, &optarg))) {
3461                options->orderfile = optarg;
3462                return argcount;
3463        }
3464        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3465                options->filter = optarg;
3466                return argcount;
3467        }
3468        else if (!strcmp(arg, "--abbrev"))
3469                options->abbrev = DEFAULT_ABBREV;
3470        else if (!prefixcmp(arg, "--abbrev=")) {
3471                options->abbrev = strtoul(arg + 9, NULL, 10);
3472                if (options->abbrev < MINIMUM_ABBREV)
3473                        options->abbrev = MINIMUM_ABBREV;
3474                else if (40 < options->abbrev)
3475                        options->abbrev = 40;
3476        }
3477        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3478                options->a_prefix = optarg;
3479                return argcount;
3480        }
3481        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3482                options->b_prefix = optarg;
3483                return argcount;
3484        }
3485        else if (!strcmp(arg, "--no-prefix"))
3486                options->a_prefix = options->b_prefix = "";
3487        else if (opt_arg(arg, '\0', "inter-hunk-context",
3488                         &options->interhunkcontext))
3489                ;
3490        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3491                options->file = fopen(optarg, "w");
3492                if (!options->file)
3493                        die_errno("Could not open '%s'", optarg);
3494                options->close_file = 1;
3495                return argcount;
3496        } else
3497                return 0;
3498        return 1;
3499}
3500
3501int parse_rename_score(const char **cp_p)
3502{
3503        unsigned long num, scale;
3504        int ch, dot;
3505        const char *cp = *cp_p;
3506
3507        num = 0;
3508        scale = 1;
3509        dot = 0;
3510        for (;;) {
3511                ch = *cp;
3512                if ( !dot && ch == '.' ) {
3513                        scale = 1;
3514                        dot = 1;
3515                } else if ( ch == '%' ) {
3516                        scale = dot ? scale*100 : 100;
3517                        cp++;   /* % is always at the end */
3518                        break;
3519                } else if ( ch >= '0' && ch <= '9' ) {
3520                        if ( scale < 100000 ) {
3521                                scale *= 10;
3522                                num = (num*10) + (ch-'0');
3523                        }
3524                } else {
3525                        break;
3526                }
3527                cp++;
3528        }
3529        *cp_p = cp;
3530
3531        /* user says num divided by scale and we say internally that
3532         * is MAX_SCORE * num / scale.
3533         */
3534        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3535}
3536
3537static int diff_scoreopt_parse(const char *opt)
3538{
3539        int opt1, opt2, cmd;
3540
3541        if (*opt++ != '-')
3542                return -1;
3543        cmd = *opt++;
3544        if (cmd == '-') {
3545                /* convert the long-form arguments into short-form versions */
3546                if (!prefixcmp(opt, "break-rewrites")) {
3547                        opt += strlen("break-rewrites");
3548                        if (*opt == 0 || *opt++ == '=')
3549                                cmd = 'B';
3550                } else if (!prefixcmp(opt, "find-copies")) {
3551                        opt += strlen("find-copies");
3552                        if (*opt == 0 || *opt++ == '=')
3553                                cmd = 'C';
3554                } else if (!prefixcmp(opt, "find-renames")) {
3555                        opt += strlen("find-renames");
3556                        if (*opt == 0 || *opt++ == '=')
3557                                cmd = 'M';
3558                }
3559        }
3560        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3561                return -1; /* that is not a -M, -C nor -B option */
3562
3563        opt1 = parse_rename_score(&opt);
3564        if (cmd != 'B')
3565                opt2 = 0;
3566        else {
3567                if (*opt == 0)
3568                        opt2 = 0;
3569                else if (*opt != '/')
3570                        return -1; /* we expect -B80/99 or -B80 */
3571                else {
3572                        opt++;
3573                        opt2 = parse_rename_score(&opt);
3574                }
3575        }
3576        if (*opt != 0)
3577                return -1;
3578        return opt1 | (opt2 << 16);
3579}
3580
3581struct diff_queue_struct diff_queued_diff;
3582
3583void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3584{
3585        if (queue->alloc <= queue->nr) {
3586                queue->alloc = alloc_nr(queue->alloc);
3587                queue->queue = xrealloc(queue->queue,
3588                                        sizeof(dp) * queue->alloc);
3589        }
3590        queue->queue[queue->nr++] = dp;
3591}
3592
3593struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3594                                 struct diff_filespec *one,
3595                                 struct diff_filespec *two)
3596{
3597        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3598        dp->one = one;
3599        dp->two = two;
3600        if (queue)
3601                diff_q(queue, dp);
3602        return dp;
3603}
3604
3605void diff_free_filepair(struct diff_filepair *p)
3606{
3607        free_filespec(p->one);
3608        free_filespec(p->two);
3609        free(p);
3610}
3611
3612/* This is different from find_unique_abbrev() in that
3613 * it stuffs the result with dots for alignment.
3614 */
3615const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3616{
3617        int abblen;
3618        const char *abbrev;
3619        if (len == 40)
3620                return sha1_to_hex(sha1);
3621
3622        abbrev = find_unique_abbrev(sha1, len);
3623        abblen = strlen(abbrev);
3624        if (abblen < 37) {
3625                static char hex[41];
3626                if (len < abblen && abblen <= len + 2)
3627                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3628                else
3629                        sprintf(hex, "%s...", abbrev);
3630                return hex;
3631        }
3632        return sha1_to_hex(sha1);
3633}
3634
3635static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3636{
3637        int line_termination = opt->line_termination;
3638        int inter_name_termination = line_termination ? '\t' : '\0';
3639        if (opt->output_prefix) {
3640                struct strbuf *msg = NULL;
3641                msg = opt->output_prefix(opt, opt->output_prefix_data);
3642                fprintf(opt->file, "%s", msg->buf);
3643        }
3644
3645        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3646                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3647                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3648                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3649        }
3650        if (p->score) {
3651                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3652                        inter_name_termination);
3653        } else {
3654                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3655        }
3656
3657        if (p->status == DIFF_STATUS_COPIED ||
3658            p->status == DIFF_STATUS_RENAMED) {
3659                const char *name_a, *name_b;
3660                name_a = p->one->path;
3661                name_b = p->two->path;
3662                strip_prefix(opt->prefix_length, &name_a, &name_b);
3663                write_name_quoted(name_a, opt->file, inter_name_termination);
3664                write_name_quoted(name_b, opt->file, line_termination);
3665        } else {
3666                const char *name_a, *name_b;
3667                name_a = p->one->mode ? p->one->path : p->two->path;
3668                name_b = NULL;
3669                strip_prefix(opt->prefix_length, &name_a, &name_b);
3670                write_name_quoted(name_a, opt->file, line_termination);
3671        }
3672}
3673
3674int diff_unmodified_pair(struct diff_filepair *p)
3675{
3676        /* This function is written stricter than necessary to support
3677         * the currently implemented transformers, but the idea is to
3678         * let transformers to produce diff_filepairs any way they want,
3679         * and filter and clean them up here before producing the output.
3680         */
3681        struct diff_filespec *one = p->one, *two = p->two;
3682
3683        if (DIFF_PAIR_UNMERGED(p))
3684                return 0; /* unmerged is interesting */
3685
3686        /* deletion, addition, mode or type change
3687         * and rename are all interesting.
3688         */
3689        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3690            DIFF_PAIR_MODE_CHANGED(p) ||
3691            strcmp(one->path, two->path))
3692                return 0;
3693
3694        /* both are valid and point at the same path.  that is, we are
3695         * dealing with a change.
3696         */
3697        if (one->sha1_valid && two->sha1_valid &&
3698            !hashcmp(one->sha1, two->sha1) &&
3699            !one->dirty_submodule && !two->dirty_submodule)
3700                return 1; /* no change */
3701        if (!one->sha1_valid && !two->sha1_valid)
3702                return 1; /* both look at the same file on the filesystem. */
3703        return 0;
3704}
3705
3706static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3707{
3708        if (diff_unmodified_pair(p))
3709                return;
3710
3711        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3712            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3713                return; /* no tree diffs in patch format */
3714
3715        run_diff(p, o);
3716}
3717
3718static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3719                            struct diffstat_t *diffstat)
3720{
3721        if (diff_unmodified_pair(p))
3722                return;
3723
3724        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3725            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3726                return; /* no useful stat for tree diffs */
3727
3728        run_diffstat(p, o, diffstat);
3729}
3730
3731static void diff_flush_checkdiff(struct diff_filepair *p,
3732                struct diff_options *o)
3733{
3734        if (diff_unmodified_pair(p))
3735                return;
3736
3737        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3738            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3739                return; /* nothing to check in tree diffs */
3740
3741        run_checkdiff(p, o);
3742}
3743
3744int diff_queue_is_empty(void)
3745{
3746        struct diff_queue_struct *q = &diff_queued_diff;
3747        int i;
3748        for (i = 0; i < q->nr; i++)
3749                if (!diff_unmodified_pair(q->queue[i]))
3750                        return 0;
3751        return 1;
3752}
3753
3754#if DIFF_DEBUG
3755void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3756{
3757        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3758                x, one ? one : "",
3759                s->path,
3760                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3761                s->mode,
3762                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3763        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3764                x, one ? one : "",
3765                s->size, s->xfrm_flags);
3766}
3767
3768void diff_debug_filepair(const struct diff_filepair *p, int i)
3769{
3770        diff_debug_filespec(p->one, i, "one");
3771        diff_debug_filespec(p->two, i, "two");
3772        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3773                p->score, p->status ? p->status : '?',
3774                p->one->rename_used, p->broken_pair);
3775}
3776
3777void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3778{
3779        int i;
3780        if (msg)
3781                fprintf(stderr, "%s\n", msg);
3782        fprintf(stderr, "q->nr = %d\n", q->nr);
3783        for (i = 0; i < q->nr; i++) {
3784                struct diff_filepair *p = q->queue[i];
3785                diff_debug_filepair(p, i);
3786        }
3787}
3788#endif
3789
3790static void diff_resolve_rename_copy(void)
3791{
3792        int i;
3793        struct diff_filepair *p;
3794        struct diff_queue_struct *q = &diff_queued_diff;
3795
3796        diff_debug_queue("resolve-rename-copy", q);
3797
3798        for (i = 0; i < q->nr; i++) {
3799                p = q->queue[i];
3800                p->status = 0; /* undecided */
3801                if (DIFF_PAIR_UNMERGED(p))
3802                        p->status = DIFF_STATUS_UNMERGED;
3803                else if (!DIFF_FILE_VALID(p->one))
3804                        p->status = DIFF_STATUS_ADDED;
3805                else if (!DIFF_FILE_VALID(p->two))
3806                        p->status = DIFF_STATUS_DELETED;
3807                else if (DIFF_PAIR_TYPE_CHANGED(p))
3808                        p->status = DIFF_STATUS_TYPE_CHANGED;
3809
3810                /* from this point on, we are dealing with a pair
3811                 * whose both sides are valid and of the same type, i.e.
3812                 * either in-place edit or rename/copy edit.
3813                 */
3814                else if (DIFF_PAIR_RENAME(p)) {
3815                        /*
3816                         * A rename might have re-connected a broken
3817                         * pair up, causing the pathnames to be the
3818                         * same again. If so, that's not a rename at
3819                         * all, just a modification..
3820                         *
3821                         * Otherwise, see if this source was used for
3822                         * multiple renames, in which case we decrement
3823                         * the count, and call it a copy.
3824                         */
3825                        if (!strcmp(p->one->path, p->two->path))
3826                                p->status = DIFF_STATUS_MODIFIED;
3827                        else if (--p->one->rename_used > 0)
3828                                p->status = DIFF_STATUS_COPIED;
3829                        else
3830                                p->status = DIFF_STATUS_RENAMED;
3831                }
3832                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3833                         p->one->mode != p->two->mode ||
3834                         p->one->dirty_submodule ||
3835                         p->two->dirty_submodule ||
3836                         is_null_sha1(p->one->sha1))
3837                        p->status = DIFF_STATUS_MODIFIED;
3838                else {
3839                        /* This is a "no-change" entry and should not
3840                         * happen anymore, but prepare for broken callers.
3841                         */
3842                        error("feeding unmodified %s to diffcore",
3843                              p->one->path);
3844                        p->status = DIFF_STATUS_UNKNOWN;
3845                }
3846        }
3847        diff_debug_queue("resolve-rename-copy done", q);
3848}
3849
3850static int check_pair_status(struct diff_filepair *p)
3851{
3852        switch (p->status) {
3853        case DIFF_STATUS_UNKNOWN:
3854                return 0;
3855        case 0:
3856                die("internal error in diff-resolve-rename-copy");
3857        default:
3858                return 1;
3859        }
3860}
3861
3862static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3863{
3864        int fmt = opt->output_format;
3865
3866        if (fmt & DIFF_FORMAT_CHECKDIFF)
3867                diff_flush_checkdiff(p, opt);
3868        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3869                diff_flush_raw(p, opt);
3870        else if (fmt & DIFF_FORMAT_NAME) {
3871                const char *name_a, *name_b;
3872                name_a = p->two->path;
3873                name_b = NULL;
3874                strip_prefix(opt->prefix_length, &name_a, &name_b);
3875                write_name_quoted(name_a, opt->file, opt->line_termination);
3876        }
3877}
3878
3879static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3880{
3881        if (fs->mode)
3882                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3883        else
3884                fprintf(file, " %s ", newdelete);
3885        write_name_quoted(fs->path, file, '\n');
3886}
3887
3888
3889static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3890                const char *line_prefix)
3891{
3892        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3893                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3894                        p->two->mode, show_name ? ' ' : '\n');
3895                if (show_name) {
3896                        write_name_quoted(p->two->path, file, '\n');
3897                }
3898        }
3899}
3900
3901static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3902                        const char *line_prefix)
3903{
3904        char *names = pprint_rename(p->one->path, p->two->path);
3905
3906        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3907        free(names);
3908        show_mode_change(file, p, 0, line_prefix);
3909}
3910
3911static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3912{
3913        FILE *file = opt->file;
3914        char *line_prefix = "";
3915
3916        if (opt->output_prefix) {
3917                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3918                line_prefix = buf->buf;
3919        }
3920
3921        switch(p->status) {
3922        case DIFF_STATUS_DELETED:
3923                fputs(line_prefix, file);
3924                show_file_mode_name(file, "delete", p->one);
3925                break;
3926        case DIFF_STATUS_ADDED:
3927                fputs(line_prefix, file);
3928                show_file_mode_name(file, "create", p->two);
3929                break;
3930        case DIFF_STATUS_COPIED:
3931                fputs(line_prefix, file);
3932                show_rename_copy(file, "copy", p, line_prefix);
3933                break;
3934        case DIFF_STATUS_RENAMED:
3935                fputs(line_prefix, file);
3936                show_rename_copy(file, "rename", p, line_prefix);
3937                break;
3938        default:
3939                if (p->score) {
3940                        fprintf(file, "%s rewrite ", line_prefix);
3941                        write_name_quoted(p->two->path, file, ' ');
3942                        fprintf(file, "(%d%%)\n", similarity_index(p));
3943                }
3944                show_mode_change(file, p, !p->score, line_prefix);
3945                break;
3946        }
3947}
3948
3949struct patch_id_t {
3950        git_SHA_CTX *ctx;
3951        int patchlen;
3952};
3953
3954static int remove_space(char *line, int len)
3955{
3956        int i;
3957        char *dst = line;
3958        unsigned char c;
3959
3960        for (i = 0; i < len; i++)
3961                if (!isspace((c = line[i])))
3962                        *dst++ = c;
3963
3964        return dst - line;
3965}
3966
3967static void patch_id_consume(void *priv, char *line, unsigned long len)
3968{
3969        struct patch_id_t *data = priv;
3970        int new_len;
3971
3972        /* Ignore line numbers when computing the SHA1 of the patch */
3973        if (!prefixcmp(line, "@@ -"))
3974                return;
3975
3976        new_len = remove_space(line, len);
3977
3978        git_SHA1_Update(data->ctx, line, new_len);
3979        data->patchlen += new_len;
3980}
3981
3982/* returns 0 upon success, and writes result into sha1 */
3983static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3984{
3985        struct diff_queue_struct *q = &diff_queued_diff;
3986        int i;
3987        git_SHA_CTX ctx;
3988        struct patch_id_t data;
3989        char buffer[PATH_MAX * 4 + 20];
3990
3991        git_SHA1_Init(&ctx);
3992        memset(&data, 0, sizeof(struct patch_id_t));
3993        data.ctx = &ctx;
3994
3995        for (i = 0; i < q->nr; i++) {
3996                xpparam_t xpp;
3997                xdemitconf_t xecfg;
3998                mmfile_t mf1, mf2;
3999                struct diff_filepair *p = q->queue[i];
4000                int len1, len2;
4001
4002                memset(&xpp, 0, sizeof(xpp));
4003                memset(&xecfg, 0, sizeof(xecfg));
4004                if (p->status == 0)
4005                        return error("internal diff status error");
4006                if (p->status == DIFF_STATUS_UNKNOWN)
4007                        continue;
4008                if (diff_unmodified_pair(p))
4009                        continue;
4010                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4011                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4012                        continue;
4013                if (DIFF_PAIR_UNMERGED(p))
4014                        continue;
4015
4016                diff_fill_sha1_info(p->one);
4017                diff_fill_sha1_info(p->two);
4018                if (fill_mmfile(&mf1, p->one) < 0 ||
4019                                fill_mmfile(&mf2, p->two) < 0)
4020                        return error("unable to read files to diff");
4021
4022                len1 = remove_space(p->one->path, strlen(p->one->path));
4023                len2 = remove_space(p->two->path, strlen(p->two->path));
4024                if (p->one->mode == 0)
4025                        len1 = snprintf(buffer, sizeof(buffer),
4026                                        "diff--gita/%.*sb/%.*s"
4027                                        "newfilemode%06o"
4028                                        "---/dev/null"
4029                                        "+++b/%.*s",
4030                                        len1, p->one->path,
4031                                        len2, p->two->path,
4032                                        p->two->mode,
4033                                        len2, p->two->path);
4034                else if (p->two->mode == 0)
4035                        len1 = snprintf(buffer, sizeof(buffer),
4036                                        "diff--gita/%.*sb/%.*s"
4037                                        "deletedfilemode%06o"
4038                                        "---a/%.*s"
4039                                        "+++/dev/null",
4040                                        len1, p->one->path,
4041                                        len2, p->two->path,
4042                                        p->one->mode,
4043                                        len1, p->one->path);
4044                else
4045                        len1 = snprintf(buffer, sizeof(buffer),
4046                                        "diff--gita/%.*sb/%.*s"
4047                                        "---a/%.*s"
4048                                        "+++b/%.*s",
4049                                        len1, p->one->path,
4050                                        len2, p->two->path,
4051                                        len1, p->one->path,
4052                                        len2, p->two->path);
4053                git_SHA1_Update(&ctx, buffer, len1);
4054
4055                if (diff_filespec_is_binary(p->one) ||
4056                    diff_filespec_is_binary(p->two)) {
4057                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4058                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4059                        continue;
4060                }
4061
4062                xpp.flags = 0;
4063                xecfg.ctxlen = 3;
4064                xecfg.flags = 0;
4065                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4066                              &xpp, &xecfg);
4067        }
4068
4069        git_SHA1_Final(sha1, &ctx);
4070        return 0;
4071}
4072
4073int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4074{
4075        struct diff_queue_struct *q = &diff_queued_diff;
4076        int i;
4077        int result = diff_get_patch_id(options, sha1);
4078
4079        for (i = 0; i < q->nr; i++)
4080                diff_free_filepair(q->queue[i]);
4081
4082        free(q->queue);
4083        DIFF_QUEUE_CLEAR(q);
4084
4085        return result;
4086}
4087
4088static int is_summary_empty(const struct diff_queue_struct *q)
4089{
4090        int i;
4091
4092        for (i = 0; i < q->nr; i++) {
4093                const struct diff_filepair *p = q->queue[i];
4094
4095                switch (p->status) {
4096                case DIFF_STATUS_DELETED:
4097                case DIFF_STATUS_ADDED:
4098                case DIFF_STATUS_COPIED:
4099                case DIFF_STATUS_RENAMED:
4100                        return 0;
4101                default:
4102                        if (p->score)
4103                                return 0;
4104                        if (p->one->mode && p->two->mode &&
4105                            p->one->mode != p->two->mode)
4106                                return 0;
4107                        break;
4108                }
4109        }
4110        return 1;
4111}
4112
4113static const char rename_limit_warning[] =
4114"inexact rename detection was skipped due to too many files.";
4115
4116static const char degrade_cc_to_c_warning[] =
4117"only found copies from modified paths due to too many files.";
4118
4119static const char rename_limit_advice[] =
4120"you may want to set your %s variable to at least "
4121"%d and retry the command.";
4122
4123void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4124{
4125        if (degraded_cc)
4126                warning(degrade_cc_to_c_warning);
4127        else if (needed)
4128                warning(rename_limit_warning);
4129        else
4130                return;
4131        if (0 < needed && needed < 32767)
4132                warning(rename_limit_advice, varname, needed);
4133}
4134
4135void diff_flush(struct diff_options *options)
4136{
4137        struct diff_queue_struct *q = &diff_queued_diff;
4138        int i, output_format = options->output_format;
4139        int separator = 0;
4140        int dirstat_by_line = 0;
4141
4142        /*
4143         * Order: raw, stat, summary, patch
4144         * or:    name/name-status/checkdiff (other bits clear)
4145         */
4146        if (!q->nr)
4147                goto free_queue;
4148
4149        if (output_format & (DIFF_FORMAT_RAW |
4150                             DIFF_FORMAT_NAME |
4151                             DIFF_FORMAT_NAME_STATUS |
4152                             DIFF_FORMAT_CHECKDIFF)) {
4153                for (i = 0; i < q->nr; i++) {
4154                        struct diff_filepair *p = q->queue[i];
4155                        if (check_pair_status(p))
4156                                flush_one_pair(p, options);
4157                }
4158                separator++;
4159        }
4160
4161        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4162                dirstat_by_line = 1;
4163
4164        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4165            dirstat_by_line) {
4166                struct diffstat_t diffstat;
4167
4168                memset(&diffstat, 0, sizeof(struct diffstat_t));
4169                for (i = 0; i < q->nr; i++) {
4170                        struct diff_filepair *p = q->queue[i];
4171                        if (check_pair_status(p))
4172                                diff_flush_stat(p, options, &diffstat);
4173                }
4174                if (output_format & DIFF_FORMAT_NUMSTAT)
4175                        show_numstat(&diffstat, options);
4176                if (output_format & DIFF_FORMAT_DIFFSTAT)
4177                        show_stats(&diffstat, options);
4178                if (output_format & DIFF_FORMAT_SHORTSTAT)
4179                        show_shortstats(&diffstat, options);
4180                if (output_format & DIFF_FORMAT_DIRSTAT)
4181                        show_dirstat_by_line(&diffstat, options);
4182                free_diffstat_info(&diffstat);
4183                separator++;
4184        }
4185        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4186                show_dirstat(options);
4187
4188        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4189                for (i = 0; i < q->nr; i++) {
4190                        diff_summary(options, q->queue[i]);
4191                }
4192                separator++;
4193        }
4194
4195        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4196            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4197            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4198                /*
4199                 * run diff_flush_patch for the exit status. setting
4200                 * options->file to /dev/null should be safe, becaue we
4201                 * aren't supposed to produce any output anyway.
4202                 */
4203                if (options->close_file)
4204                        fclose(options->file);
4205                options->file = fopen("/dev/null", "w");
4206                if (!options->file)
4207                        die_errno("Could not open /dev/null");
4208                options->close_file = 1;
4209                for (i = 0; i < q->nr; i++) {
4210                        struct diff_filepair *p = q->queue[i];
4211                        if (check_pair_status(p))
4212                                diff_flush_patch(p, options);
4213                        if (options->found_changes)
4214                                break;
4215                }
4216        }
4217
4218        if (output_format & DIFF_FORMAT_PATCH) {
4219                if (separator) {
4220                        putc(options->line_termination, options->file);
4221                        if (options->stat_sep) {
4222                                /* attach patch instead of inline */
4223                                fputs(options->stat_sep, options->file);
4224                        }
4225                }
4226
4227                for (i = 0; i < q->nr; i++) {
4228                        struct diff_filepair *p = q->queue[i];
4229                        if (check_pair_status(p))
4230                                diff_flush_patch(p, options);
4231                }
4232        }
4233
4234        if (output_format & DIFF_FORMAT_CALLBACK)
4235                options->format_callback(q, options, options->format_callback_data);
4236
4237        for (i = 0; i < q->nr; i++)
4238                diff_free_filepair(q->queue[i]);
4239free_queue:
4240        free(q->queue);
4241        DIFF_QUEUE_CLEAR(q);
4242        if (options->close_file)
4243                fclose(options->file);
4244
4245        /*
4246         * Report the content-level differences with HAS_CHANGES;
4247         * diff_addremove/diff_change does not set the bit when
4248         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4249         */
4250        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4251                if (options->found_changes)
4252                        DIFF_OPT_SET(options, HAS_CHANGES);
4253                else
4254                        DIFF_OPT_CLR(options, HAS_CHANGES);
4255        }
4256}
4257
4258static void diffcore_apply_filter(const char *filter)
4259{
4260        int i;
4261        struct diff_queue_struct *q = &diff_queued_diff;
4262        struct diff_queue_struct outq;
4263        DIFF_QUEUE_CLEAR(&outq);
4264
4265        if (!filter)
4266                return;
4267
4268        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4269                int found;
4270                for (i = found = 0; !found && i < q->nr; i++) {
4271                        struct diff_filepair *p = q->queue[i];
4272                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4273                             ((p->score &&
4274                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4275                              (!p->score &&
4276                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4277                            ((p->status != DIFF_STATUS_MODIFIED) &&
4278                             strchr(filter, p->status)))
4279                                found++;
4280                }
4281                if (found)
4282                        return;
4283
4284                /* otherwise we will clear the whole queue
4285                 * by copying the empty outq at the end of this
4286                 * function, but first clear the current entries
4287                 * in the queue.
4288                 */
4289                for (i = 0; i < q->nr; i++)
4290                        diff_free_filepair(q->queue[i]);
4291        }
4292        else {
4293                /* Only the matching ones */
4294                for (i = 0; i < q->nr; i++) {
4295                        struct diff_filepair *p = q->queue[i];
4296
4297                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4298                             ((p->score &&
4299                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4300                              (!p->score &&
4301                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4302                            ((p->status != DIFF_STATUS_MODIFIED) &&
4303                             strchr(filter, p->status)))
4304                                diff_q(&outq, p);
4305                        else
4306                                diff_free_filepair(p);
4307                }
4308        }
4309        free(q->queue);
4310        *q = outq;
4311}
4312
4313/* Check whether two filespecs with the same mode and size are identical */
4314static int diff_filespec_is_identical(struct diff_filespec *one,
4315                                      struct diff_filespec *two)
4316{
4317        if (S_ISGITLINK(one->mode))
4318                return 0;
4319        if (diff_populate_filespec(one, 0))
4320                return 0;
4321        if (diff_populate_filespec(two, 0))
4322                return 0;
4323        return !memcmp(one->data, two->data, one->size);
4324}
4325
4326static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4327{
4328        int i;
4329        struct diff_queue_struct *q = &diff_queued_diff;
4330        struct diff_queue_struct outq;
4331        DIFF_QUEUE_CLEAR(&outq);
4332
4333        for (i = 0; i < q->nr; i++) {
4334                struct diff_filepair *p = q->queue[i];
4335
4336                /*
4337                 * 1. Entries that come from stat info dirtiness
4338                 *    always have both sides (iow, not create/delete),
4339                 *    one side of the object name is unknown, with
4340                 *    the same mode and size.  Keep the ones that
4341                 *    do not match these criteria.  They have real
4342                 *    differences.
4343                 *
4344                 * 2. At this point, the file is known to be modified,
4345                 *    with the same mode and size, and the object
4346                 *    name of one side is unknown.  Need to inspect
4347                 *    the identical contents.
4348                 */
4349                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4350                    !DIFF_FILE_VALID(p->two) ||
4351                    (p->one->sha1_valid && p->two->sha1_valid) ||
4352                    (p->one->mode != p->two->mode) ||
4353                    diff_populate_filespec(p->one, 1) ||
4354                    diff_populate_filespec(p->two, 1) ||
4355                    (p->one->size != p->two->size) ||
4356                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4357                        diff_q(&outq, p);
4358                else {
4359                        /*
4360                         * The caller can subtract 1 from skip_stat_unmatch
4361                         * to determine how many paths were dirty only
4362                         * due to stat info mismatch.
4363                         */
4364                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4365                                diffopt->skip_stat_unmatch++;
4366                        diff_free_filepair(p);
4367                }
4368        }
4369        free(q->queue);
4370        *q = outq;
4371}
4372
4373static int diffnamecmp(const void *a_, const void *b_)
4374{
4375        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4376        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4377        const char *name_a, *name_b;
4378
4379        name_a = a->one ? a->one->path : a->two->path;
4380        name_b = b->one ? b->one->path : b->two->path;
4381        return strcmp(name_a, name_b);
4382}
4383
4384void diffcore_fix_diff_index(struct diff_options *options)
4385{
4386        struct diff_queue_struct *q = &diff_queued_diff;
4387        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4388}
4389
4390void diffcore_std(struct diff_options *options)
4391{
4392        if (options->skip_stat_unmatch)
4393                diffcore_skip_stat_unmatch(options);
4394        if (!options->found_follow) {
4395                /* See try_to_follow_renames() in tree-diff.c */
4396                if (options->break_opt != -1)
4397                        diffcore_break(options->break_opt);
4398                if (options->detect_rename)
4399                        diffcore_rename(options);
4400                if (options->break_opt != -1)
4401                        diffcore_merge_broken();
4402        }
4403        if (options->pickaxe)
4404                diffcore_pickaxe(options);
4405        if (options->orderfile)
4406                diffcore_order(options->orderfile);
4407        if (!options->found_follow)
4408                /* See try_to_follow_renames() in tree-diff.c */
4409                diff_resolve_rename_copy();
4410        diffcore_apply_filter(options->filter);
4411
4412        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4413                DIFF_OPT_SET(options, HAS_CHANGES);
4414        else
4415                DIFF_OPT_CLR(options, HAS_CHANGES);
4416
4417        options->found_follow = 0;
4418}
4419
4420int diff_result_code(struct diff_options *opt, int status)
4421{
4422        int result = 0;
4423
4424        diff_warn_rename_limit("diff.renamelimit",
4425                               opt->needed_rename_limit,
4426                               opt->degraded_cc_to_c);
4427        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4428            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4429                return status;
4430        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4431            DIFF_OPT_TST(opt, HAS_CHANGES))
4432                result |= 01;
4433        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4434            DIFF_OPT_TST(opt, CHECK_FAILED))
4435                result |= 02;
4436        return result;
4437}
4438
4439/*
4440 * Shall changes to this submodule be ignored?
4441 *
4442 * Submodule changes can be configured to be ignored separately for each path,
4443 * but that configuration can be overridden from the command line.
4444 */
4445static int is_submodule_ignored(const char *path, struct diff_options *options)
4446{
4447        int ignored = 0;
4448        unsigned orig_flags = options->flags;
4449        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4450                set_diffopt_flags_from_submodule_config(options, path);
4451        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4452                ignored = 1;
4453        options->flags = orig_flags;
4454        return ignored;
4455}
4456
4457void diff_addremove(struct diff_options *options,
4458                    int addremove, unsigned mode,
4459                    const unsigned char *sha1,
4460                    const char *concatpath, unsigned dirty_submodule)
4461{
4462        struct diff_filespec *one, *two;
4463
4464        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4465                return;
4466
4467        /* This may look odd, but it is a preparation for
4468         * feeding "there are unchanged files which should
4469         * not produce diffs, but when you are doing copy
4470         * detection you would need them, so here they are"
4471         * entries to the diff-core.  They will be prefixed
4472         * with something like '=' or '*' (I haven't decided
4473         * which but should not make any difference).
4474         * Feeding the same new and old to diff_change()
4475         * also has the same effect.
4476         * Before the final output happens, they are pruned after
4477         * merged into rename/copy pairs as appropriate.
4478         */
4479        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4480                addremove = (addremove == '+' ? '-' :
4481                             addremove == '-' ? '+' : addremove);
4482
4483        if (options->prefix &&
4484            strncmp(concatpath, options->prefix, options->prefix_length))
4485                return;
4486
4487        one = alloc_filespec(concatpath);
4488        two = alloc_filespec(concatpath);
4489
4490        if (addremove != '+')
4491                fill_filespec(one, sha1, mode);
4492        if (addremove != '-') {
4493                fill_filespec(two, sha1, mode);
4494                two->dirty_submodule = dirty_submodule;
4495        }
4496
4497        diff_queue(&diff_queued_diff, one, two);
4498        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4499                DIFF_OPT_SET(options, HAS_CHANGES);
4500}
4501
4502void diff_change(struct diff_options *options,
4503                 unsigned old_mode, unsigned new_mode,
4504                 const unsigned char *old_sha1,
4505                 const unsigned char *new_sha1,
4506                 const char *concatpath,
4507                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4508{
4509        struct diff_filespec *one, *two;
4510
4511        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4512            is_submodule_ignored(concatpath, options))
4513                return;
4514
4515        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4516                unsigned tmp;
4517                const unsigned char *tmp_c;
4518                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4519                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4520                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4521                        new_dirty_submodule = tmp;
4522        }
4523
4524        if (options->prefix &&
4525            strncmp(concatpath, options->prefix, options->prefix_length))
4526                return;
4527
4528        one = alloc_filespec(concatpath);
4529        two = alloc_filespec(concatpath);
4530        fill_filespec(one, old_sha1, old_mode);
4531        fill_filespec(two, new_sha1, new_mode);
4532        one->dirty_submodule = old_dirty_submodule;
4533        two->dirty_submodule = new_dirty_submodule;
4534
4535        diff_queue(&diff_queued_diff, one, two);
4536        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4537                DIFF_OPT_SET(options, HAS_CHANGES);
4538}
4539
4540struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4541{
4542        struct diff_filepair *pair;
4543        struct diff_filespec *one, *two;
4544
4545        if (options->prefix &&
4546            strncmp(path, options->prefix, options->prefix_length))
4547                return NULL;
4548
4549        one = alloc_filespec(path);
4550        two = alloc_filespec(path);
4551        pair = diff_queue(&diff_queued_diff, one, two);
4552        pair->is_unmerged = 1;
4553        return pair;
4554}
4555
4556static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4557                size_t *outsize)
4558{
4559        struct diff_tempfile *temp;
4560        const char *argv[3];
4561        const char **arg = argv;
4562        struct child_process child;
4563        struct strbuf buf = STRBUF_INIT;
4564        int err = 0;
4565
4566        temp = prepare_temp_file(spec->path, spec);
4567        *arg++ = pgm;
4568        *arg++ = temp->name;
4569        *arg = NULL;
4570
4571        memset(&child, 0, sizeof(child));
4572        child.use_shell = 1;
4573        child.argv = argv;
4574        child.out = -1;
4575        if (start_command(&child)) {
4576                remove_tempfile();
4577                return NULL;
4578        }
4579
4580        if (strbuf_read(&buf, child.out, 0) < 0)
4581                err = error("error reading from textconv command '%s'", pgm);
4582        close(child.out);
4583
4584        if (finish_command(&child) || err) {
4585                strbuf_release(&buf);
4586                remove_tempfile();
4587                return NULL;
4588        }
4589        remove_tempfile();
4590
4591        return strbuf_detach(&buf, outsize);
4592}
4593
4594size_t fill_textconv(struct userdiff_driver *driver,
4595                     struct diff_filespec *df,
4596                     char **outbuf)
4597{
4598        size_t size;
4599
4600        if (!driver || !driver->textconv) {
4601                if (!DIFF_FILE_VALID(df)) {
4602                        *outbuf = "";
4603                        return 0;
4604                }
4605                if (diff_populate_filespec(df, 0))
4606                        die("unable to read files to diff");
4607                *outbuf = df->data;
4608                return df->size;
4609        }
4610
4611        if (driver->textconv_cache && df->sha1_valid) {
4612                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4613                                          &size);
4614                if (*outbuf)
4615                        return size;
4616        }
4617
4618        *outbuf = run_textconv(driver->textconv, df, &size);
4619        if (!*outbuf)
4620                die("unable to read files to diff");
4621
4622        if (driver->textconv_cache && df->sha1_valid) {
4623                /* ignore errors, as we might be in a readonly repository */
4624                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4625                                size);
4626                /*
4627                 * we could save up changes and flush them all at the end,
4628                 * but we would need an extra call after all diffing is done.
4629                 * Since generating a cache entry is the slow path anyway,
4630                 * this extra overhead probably isn't a big deal.
4631                 */
4632                notes_cache_write(driver->textconv_cache);
4633        }
4634
4635        return size;
4636}