diff.con commit drop odd return value semantics from userdiff_config (6680a08)
   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);
 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        if (git_color_config(var, value, cb) < 0)
 168                return -1;
 169
 170        return git_diff_basic_config(var, value, cb);
 171}
 172
 173int git_diff_basic_config(const char *var, const char *value, void *cb)
 174{
 175        if (!strcmp(var, "diff.renamelimit")) {
 176                diff_rename_limit_default = git_config_int(var, value);
 177                return 0;
 178        }
 179
 180        if (userdiff_config(var, value) < 0)
 181                return -1;
 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_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        const char *name_a_tab, *name_b_tab;
 587        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 588        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 589        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 590        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 591        const char *a_prefix, *b_prefix;
 592        char *data_one, *data_two;
 593        size_t size_one, size_two;
 594        struct emit_callback ecbdata;
 595        char *line_prefix = "";
 596        struct strbuf *msgbuf;
 597
 598        if (o && o->output_prefix) {
 599                msgbuf = o->output_prefix(o, o->output_prefix_data);
 600                line_prefix = msgbuf->buf;
 601        }
 602
 603        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 604                a_prefix = o->b_prefix;
 605                b_prefix = o->a_prefix;
 606        } else {
 607                a_prefix = o->a_prefix;
 608                b_prefix = o->b_prefix;
 609        }
 610
 611        name_a += (*name_a == '/');
 612        name_b += (*name_b == '/');
 613        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 614        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 615
 616        strbuf_reset(&a_name);
 617        strbuf_reset(&b_name);
 618        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 619        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 620
 621        size_one = fill_textconv(textconv_one, one, &data_one);
 622        size_two = fill_textconv(textconv_two, two, &data_two);
 623
 624        memset(&ecbdata, 0, sizeof(ecbdata));
 625        ecbdata.color_diff = want_color(o->use_color);
 626        ecbdata.found_changesp = &o->found_changes;
 627        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 628        ecbdata.opt = o;
 629        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 630                mmfile_t mf1, mf2;
 631                mf1.ptr = (char *)data_one;
 632                mf2.ptr = (char *)data_two;
 633                mf1.size = size_one;
 634                mf2.size = size_two;
 635                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 636        }
 637        ecbdata.lno_in_preimage = 1;
 638        ecbdata.lno_in_postimage = 1;
 639
 640        lc_a = count_lines(data_one, size_one);
 641        lc_b = count_lines(data_two, size_two);
 642        fprintf(o->file,
 643                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 644                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 645                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 646                line_prefix, fraginfo);
 647        if (!o->irreversible_delete)
 648                print_line_count(o->file, lc_a);
 649        else
 650                fprintf(o->file, "?,?");
 651        fprintf(o->file, " +");
 652        print_line_count(o->file, lc_b);
 653        fprintf(o->file, " @@%s\n", reset);
 654        if (lc_a && !o->irreversible_delete)
 655                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 656        if (lc_b)
 657                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 658        if (textconv_one)
 659                free((char *)data_one);
 660        if (textconv_two)
 661                free((char *)data_two);
 662}
 663
 664struct diff_words_buffer {
 665        mmfile_t text;
 666        long alloc;
 667        struct diff_words_orig {
 668                const char *begin, *end;
 669        } *orig;
 670        int orig_nr, orig_alloc;
 671};
 672
 673static void diff_words_append(char *line, unsigned long len,
 674                struct diff_words_buffer *buffer)
 675{
 676        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 677        line++;
 678        len--;
 679        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 680        buffer->text.size += len;
 681        buffer->text.ptr[buffer->text.size] = '\0';
 682}
 683
 684struct diff_words_style_elem {
 685        const char *prefix;
 686        const char *suffix;
 687        const char *color; /* NULL; filled in by the setup code if
 688                            * color is enabled */
 689};
 690
 691struct diff_words_style {
 692        enum diff_words_type type;
 693        struct diff_words_style_elem new, old, ctx;
 694        const char *newline;
 695};
 696
 697static struct diff_words_style diff_words_styles[] = {
 698        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 699        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 700        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 701};
 702
 703struct diff_words_data {
 704        struct diff_words_buffer minus, plus;
 705        const char *current_plus;
 706        int last_minus;
 707        struct diff_options *opt;
 708        regex_t *word_regex;
 709        enum diff_words_type type;
 710        struct diff_words_style *style;
 711};
 712
 713static int fn_out_diff_words_write_helper(FILE *fp,
 714                                          struct diff_words_style_elem *st_el,
 715                                          const char *newline,
 716                                          size_t count, const char *buf,
 717                                          const char *line_prefix)
 718{
 719        int print = 0;
 720
 721        while (count) {
 722                char *p = memchr(buf, '\n', count);
 723                if (print)
 724                        fputs(line_prefix, fp);
 725                if (p != buf) {
 726                        if (st_el->color && fputs(st_el->color, fp) < 0)
 727                                return -1;
 728                        if (fputs(st_el->prefix, fp) < 0 ||
 729                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 730                            fputs(st_el->suffix, fp) < 0)
 731                                return -1;
 732                        if (st_el->color && *st_el->color
 733                            && fputs(GIT_COLOR_RESET, fp) < 0)
 734                                return -1;
 735                }
 736                if (!p)
 737                        return 0;
 738                if (fputs(newline, fp) < 0)
 739                        return -1;
 740                count -= p + 1 - buf;
 741                buf = p + 1;
 742                print = 1;
 743        }
 744        return 0;
 745}
 746
 747/*
 748 * '--color-words' algorithm can be described as:
 749 *
 750 *   1. collect a the minus/plus lines of a diff hunk, divided into
 751 *      minus-lines and plus-lines;
 752 *
 753 *   2. break both minus-lines and plus-lines into words and
 754 *      place them into two mmfile_t with one word for each line;
 755 *
 756 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 757 *
 758 * And for the common parts of the both file, we output the plus side text.
 759 * diff_words->current_plus is used to trace the current position of the plus file
 760 * which printed. diff_words->last_minus is used to trace the last minus word
 761 * printed.
 762 *
 763 * For '--graph' to work with '--color-words', we need to output the graph prefix
 764 * on each line of color words output. Generally, there are two conditions on
 765 * which we should output the prefix.
 766 *
 767 *   1. diff_words->last_minus == 0 &&
 768 *      diff_words->current_plus == diff_words->plus.text.ptr
 769 *
 770 *      that is: the plus text must start as a new line, and if there is no minus
 771 *      word printed, a graph prefix must be printed.
 772 *
 773 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 774 *      *(diff_words->current_plus - 1) == '\n'
 775 *
 776 *      that is: a graph prefix must be printed following a '\n'
 777 */
 778static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 779{
 780        if ((diff_words->last_minus == 0 &&
 781                diff_words->current_plus == diff_words->plus.text.ptr) ||
 782                (diff_words->current_plus > diff_words->plus.text.ptr &&
 783                *(diff_words->current_plus - 1) == '\n')) {
 784                return 1;
 785        } else {
 786                return 0;
 787        }
 788}
 789
 790static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 791{
 792        struct diff_words_data *diff_words = priv;
 793        struct diff_words_style *style = diff_words->style;
 794        int minus_first, minus_len, plus_first, plus_len;
 795        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 796        struct diff_options *opt = diff_words->opt;
 797        struct strbuf *msgbuf;
 798        char *line_prefix = "";
 799
 800        if (line[0] != '@' || parse_hunk_header(line, len,
 801                        &minus_first, &minus_len, &plus_first, &plus_len))
 802                return;
 803
 804        assert(opt);
 805        if (opt->output_prefix) {
 806                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 807                line_prefix = msgbuf->buf;
 808        }
 809
 810        /* POSIX requires that first be decremented by one if len == 0... */
 811        if (minus_len) {
 812                minus_begin = diff_words->minus.orig[minus_first].begin;
 813                minus_end =
 814                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 815        } else
 816                minus_begin = minus_end =
 817                        diff_words->minus.orig[minus_first].end;
 818
 819        if (plus_len) {
 820                plus_begin = diff_words->plus.orig[plus_first].begin;
 821                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 822        } else
 823                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 824
 825        if (color_words_output_graph_prefix(diff_words)) {
 826                fputs(line_prefix, diff_words->opt->file);
 827        }
 828        if (diff_words->current_plus != plus_begin) {
 829                fn_out_diff_words_write_helper(diff_words->opt->file,
 830                                &style->ctx, style->newline,
 831                                plus_begin - diff_words->current_plus,
 832                                diff_words->current_plus, line_prefix);
 833                if (*(plus_begin - 1) == '\n')
 834                        fputs(line_prefix, diff_words->opt->file);
 835        }
 836        if (minus_begin != minus_end) {
 837                fn_out_diff_words_write_helper(diff_words->opt->file,
 838                                &style->old, style->newline,
 839                                minus_end - minus_begin, minus_begin,
 840                                line_prefix);
 841        }
 842        if (plus_begin != plus_end) {
 843                fn_out_diff_words_write_helper(diff_words->opt->file,
 844                                &style->new, style->newline,
 845                                plus_end - plus_begin, plus_begin,
 846                                line_prefix);
 847        }
 848
 849        diff_words->current_plus = plus_end;
 850        diff_words->last_minus = minus_first;
 851}
 852
 853/* This function starts looking at *begin, and returns 0 iff a word was found. */
 854static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 855                int *begin, int *end)
 856{
 857        if (word_regex && *begin < buffer->size) {
 858                regmatch_t match[1];
 859                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 860                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 861                                        '\n', match[0].rm_eo - match[0].rm_so);
 862                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 863                        *begin += match[0].rm_so;
 864                        return *begin >= *end;
 865                }
 866                return -1;
 867        }
 868
 869        /* find the next word */
 870        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 871                (*begin)++;
 872        if (*begin >= buffer->size)
 873                return -1;
 874
 875        /* find the end of the word */
 876        *end = *begin + 1;
 877        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 878                (*end)++;
 879
 880        return 0;
 881}
 882
 883/*
 884 * This function splits the words in buffer->text, stores the list with
 885 * newline separator into out, and saves the offsets of the original words
 886 * in buffer->orig.
 887 */
 888static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 889                regex_t *word_regex)
 890{
 891        int i, j;
 892        long alloc = 0;
 893
 894        out->size = 0;
 895        out->ptr = NULL;
 896
 897        /* fake an empty "0th" word */
 898        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 899        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 900        buffer->orig_nr = 1;
 901
 902        for (i = 0; i < buffer->text.size; i++) {
 903                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 904                        return;
 905
 906                /* store original boundaries */
 907                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 908                                buffer->orig_alloc);
 909                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 910                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 911                buffer->orig_nr++;
 912
 913                /* store one word */
 914                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 915                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 916                out->ptr[out->size + j - i] = '\n';
 917                out->size += j - i + 1;
 918
 919                i = j - 1;
 920        }
 921}
 922
 923/* this executes the word diff on the accumulated buffers */
 924static void diff_words_show(struct diff_words_data *diff_words)
 925{
 926        xpparam_t xpp;
 927        xdemitconf_t xecfg;
 928        mmfile_t minus, plus;
 929        struct diff_words_style *style = diff_words->style;
 930
 931        struct diff_options *opt = diff_words->opt;
 932        struct strbuf *msgbuf;
 933        char *line_prefix = "";
 934
 935        assert(opt);
 936        if (opt->output_prefix) {
 937                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 938                line_prefix = msgbuf->buf;
 939        }
 940
 941        /* special case: only removal */
 942        if (!diff_words->plus.text.size) {
 943                fputs(line_prefix, diff_words->opt->file);
 944                fn_out_diff_words_write_helper(diff_words->opt->file,
 945                        &style->old, style->newline,
 946                        diff_words->minus.text.size,
 947                        diff_words->minus.text.ptr, line_prefix);
 948                diff_words->minus.text.size = 0;
 949                return;
 950        }
 951
 952        diff_words->current_plus = diff_words->plus.text.ptr;
 953        diff_words->last_minus = 0;
 954
 955        memset(&xpp, 0, sizeof(xpp));
 956        memset(&xecfg, 0, sizeof(xecfg));
 957        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 958        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 959        xpp.flags = 0;
 960        /* as only the hunk header will be parsed, we need a 0-context */
 961        xecfg.ctxlen = 0;
 962        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 963                      &xpp, &xecfg);
 964        free(minus.ptr);
 965        free(plus.ptr);
 966        if (diff_words->current_plus != diff_words->plus.text.ptr +
 967                        diff_words->plus.text.size) {
 968                if (color_words_output_graph_prefix(diff_words))
 969                        fputs(line_prefix, diff_words->opt->file);
 970                fn_out_diff_words_write_helper(diff_words->opt->file,
 971                        &style->ctx, style->newline,
 972                        diff_words->plus.text.ptr + diff_words->plus.text.size
 973                        - diff_words->current_plus, diff_words->current_plus,
 974                        line_prefix);
 975        }
 976        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 977}
 978
 979/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 980static void diff_words_flush(struct emit_callback *ecbdata)
 981{
 982        if (ecbdata->diff_words->minus.text.size ||
 983            ecbdata->diff_words->plus.text.size)
 984                diff_words_show(ecbdata->diff_words);
 985}
 986
 987static void free_diff_words_data(struct emit_callback *ecbdata)
 988{
 989        if (ecbdata->diff_words) {
 990                diff_words_flush(ecbdata);
 991                free (ecbdata->diff_words->minus.text.ptr);
 992                free (ecbdata->diff_words->minus.orig);
 993                free (ecbdata->diff_words->plus.text.ptr);
 994                free (ecbdata->diff_words->plus.orig);
 995                if (ecbdata->diff_words->word_regex) {
 996                        regfree(ecbdata->diff_words->word_regex);
 997                        free(ecbdata->diff_words->word_regex);
 998                }
 999                free(ecbdata->diff_words);
1000                ecbdata->diff_words = NULL;
1001        }
1002}
1003
1004const char *diff_get_color(int diff_use_color, enum color_diff ix)
1005{
1006        if (want_color(diff_use_color))
1007                return diff_colors[ix];
1008        return "";
1009}
1010
1011static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1012{
1013        const char *cp;
1014        unsigned long allot;
1015        size_t l = len;
1016
1017        if (ecb->truncate)
1018                return ecb->truncate(line, len);
1019        cp = line;
1020        allot = l;
1021        while (0 < l) {
1022                (void) utf8_width(&cp, &l);
1023                if (!cp)
1024                        break; /* truncated in the middle? */
1025        }
1026        return allot - l;
1027}
1028
1029static void find_lno(const char *line, struct emit_callback *ecbdata)
1030{
1031        const char *p;
1032        ecbdata->lno_in_preimage = 0;
1033        ecbdata->lno_in_postimage = 0;
1034        p = strchr(line, '-');
1035        if (!p)
1036                return; /* cannot happen */
1037        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1038        p = strchr(p, '+');
1039        if (!p)
1040                return; /* cannot happen */
1041        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1042}
1043
1044static void fn_out_consume(void *priv, char *line, unsigned long len)
1045{
1046        struct emit_callback *ecbdata = priv;
1047        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1048        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1049        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1050        struct diff_options *o = ecbdata->opt;
1051        char *line_prefix = "";
1052        struct strbuf *msgbuf;
1053
1054        if (o && o->output_prefix) {
1055                msgbuf = o->output_prefix(o, o->output_prefix_data);
1056                line_prefix = msgbuf->buf;
1057        }
1058
1059        if (ecbdata->header) {
1060                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1061                strbuf_reset(ecbdata->header);
1062                ecbdata->header = NULL;
1063        }
1064        *(ecbdata->found_changesp) = 1;
1065
1066        if (ecbdata->label_path[0]) {
1067                const char *name_a_tab, *name_b_tab;
1068
1069                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1070                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1071
1072                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1073                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1074                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1075                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1076                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1077        }
1078
1079        if (diff_suppress_blank_empty
1080            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1081                line[0] = '\n';
1082                len = 1;
1083        }
1084
1085        if (line[0] == '@') {
1086                if (ecbdata->diff_words)
1087                        diff_words_flush(ecbdata);
1088                len = sane_truncate_line(ecbdata, line, len);
1089                find_lno(line, ecbdata);
1090                emit_hunk_header(ecbdata, line, len);
1091                if (line[len-1] != '\n')
1092                        putc('\n', ecbdata->opt->file);
1093                return;
1094        }
1095
1096        if (len < 1) {
1097                emit_line(ecbdata->opt, reset, reset, line, len);
1098                if (ecbdata->diff_words
1099                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1100                        fputs("~\n", ecbdata->opt->file);
1101                return;
1102        }
1103
1104        if (ecbdata->diff_words) {
1105                if (line[0] == '-') {
1106                        diff_words_append(line, len,
1107                                          &ecbdata->diff_words->minus);
1108                        return;
1109                } else if (line[0] == '+') {
1110                        diff_words_append(line, len,
1111                                          &ecbdata->diff_words->plus);
1112                        return;
1113                } else if (!prefixcmp(line, "\\ ")) {
1114                        /*
1115                         * Eat the "no newline at eof" marker as if we
1116                         * saw a "+" or "-" line with nothing on it,
1117                         * and return without diff_words_flush() to
1118                         * defer processing. If this is the end of
1119                         * preimage, more "+" lines may come after it.
1120                         */
1121                        return;
1122                }
1123                diff_words_flush(ecbdata);
1124                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1125                        emit_line(ecbdata->opt, plain, reset, line, len);
1126                        fputs("~\n", ecbdata->opt->file);
1127                } else {
1128                        /*
1129                         * Skip the prefix character, if any.  With
1130                         * diff_suppress_blank_empty, there may be
1131                         * none.
1132                         */
1133                        if (line[0] != '\n') {
1134                              line++;
1135                              len--;
1136                        }
1137                        emit_line(ecbdata->opt, plain, reset, line, len);
1138                }
1139                return;
1140        }
1141
1142        if (line[0] != '+') {
1143                const char *color =
1144                        diff_get_color(ecbdata->color_diff,
1145                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1146                ecbdata->lno_in_preimage++;
1147                if (line[0] == ' ')
1148                        ecbdata->lno_in_postimage++;
1149                emit_line(ecbdata->opt, color, reset, line, len);
1150        } else {
1151                ecbdata->lno_in_postimage++;
1152                emit_add_line(reset, ecbdata, line + 1, len - 1);
1153        }
1154}
1155
1156static char *pprint_rename(const char *a, const char *b)
1157{
1158        const char *old = a;
1159        const char *new = b;
1160        struct strbuf name = STRBUF_INIT;
1161        int pfx_length, sfx_length;
1162        int len_a = strlen(a);
1163        int len_b = strlen(b);
1164        int a_midlen, b_midlen;
1165        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1166        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1167
1168        if (qlen_a || qlen_b) {
1169                quote_c_style(a, &name, NULL, 0);
1170                strbuf_addstr(&name, " => ");
1171                quote_c_style(b, &name, NULL, 0);
1172                return strbuf_detach(&name, NULL);
1173        }
1174
1175        /* Find common prefix */
1176        pfx_length = 0;
1177        while (*old && *new && *old == *new) {
1178                if (*old == '/')
1179                        pfx_length = old - a + 1;
1180                old++;
1181                new++;
1182        }
1183
1184        /* Find common suffix */
1185        old = a + len_a;
1186        new = b + len_b;
1187        sfx_length = 0;
1188        while (a <= old && b <= new && *old == *new) {
1189                if (*old == '/')
1190                        sfx_length = len_a - (old - a);
1191                old--;
1192                new--;
1193        }
1194
1195        /*
1196         * pfx{mid-a => mid-b}sfx
1197         * {pfx-a => pfx-b}sfx
1198         * pfx{sfx-a => sfx-b}
1199         * name-a => name-b
1200         */
1201        a_midlen = len_a - pfx_length - sfx_length;
1202        b_midlen = len_b - pfx_length - sfx_length;
1203        if (a_midlen < 0)
1204                a_midlen = 0;
1205        if (b_midlen < 0)
1206                b_midlen = 0;
1207
1208        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1209        if (pfx_length + sfx_length) {
1210                strbuf_add(&name, a, pfx_length);
1211                strbuf_addch(&name, '{');
1212        }
1213        strbuf_add(&name, a + pfx_length, a_midlen);
1214        strbuf_addstr(&name, " => ");
1215        strbuf_add(&name, b + pfx_length, b_midlen);
1216        if (pfx_length + sfx_length) {
1217                strbuf_addch(&name, '}');
1218                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1219        }
1220        return strbuf_detach(&name, NULL);
1221}
1222
1223struct diffstat_t {
1224        int nr;
1225        int alloc;
1226        struct diffstat_file {
1227                char *from_name;
1228                char *name;
1229                char *print_name;
1230                unsigned is_unmerged:1;
1231                unsigned is_binary:1;
1232                unsigned is_renamed:1;
1233                uintmax_t added, deleted;
1234        } **files;
1235};
1236
1237static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1238                                          const char *name_a,
1239                                          const char *name_b)
1240{
1241        struct diffstat_file *x;
1242        x = xcalloc(sizeof (*x), 1);
1243        if (diffstat->nr == diffstat->alloc) {
1244                diffstat->alloc = alloc_nr(diffstat->alloc);
1245                diffstat->files = xrealloc(diffstat->files,
1246                                diffstat->alloc * sizeof(x));
1247        }
1248        diffstat->files[diffstat->nr++] = x;
1249        if (name_b) {
1250                x->from_name = xstrdup(name_a);
1251                x->name = xstrdup(name_b);
1252                x->is_renamed = 1;
1253        }
1254        else {
1255                x->from_name = NULL;
1256                x->name = xstrdup(name_a);
1257        }
1258        return x;
1259}
1260
1261static void diffstat_consume(void *priv, char *line, unsigned long len)
1262{
1263        struct diffstat_t *diffstat = priv;
1264        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1265
1266        if (line[0] == '+')
1267                x->added++;
1268        else if (line[0] == '-')
1269                x->deleted++;
1270}
1271
1272const char mime_boundary_leader[] = "------------";
1273
1274static int scale_linear(int it, int width, int max_change)
1275{
1276        /*
1277         * make sure that at least one '-' is printed if there were deletions,
1278         * and likewise for '+'.
1279         */
1280        if (max_change < 2)
1281                return it;
1282        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1283}
1284
1285static void show_name(FILE *file,
1286                      const char *prefix, const char *name, int len)
1287{
1288        fprintf(file, " %s%-*s |", prefix, len, name);
1289}
1290
1291static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1292{
1293        if (cnt <= 0)
1294                return;
1295        fprintf(file, "%s", set);
1296        while (cnt--)
1297                putc(ch, file);
1298        fprintf(file, "%s", reset);
1299}
1300
1301static void fill_print_name(struct diffstat_file *file)
1302{
1303        char *pname;
1304
1305        if (file->print_name)
1306                return;
1307
1308        if (!file->is_renamed) {
1309                struct strbuf buf = STRBUF_INIT;
1310                if (quote_c_style(file->name, &buf, NULL, 0)) {
1311                        pname = strbuf_detach(&buf, NULL);
1312                } else {
1313                        pname = file->name;
1314                        strbuf_release(&buf);
1315                }
1316        } else {
1317                pname = pprint_rename(file->from_name, file->name);
1318        }
1319        file->print_name = pname;
1320}
1321
1322static void show_stats(struct diffstat_t *data, struct diff_options *options)
1323{
1324        int i, len, add, del, adds = 0, dels = 0;
1325        uintmax_t max_change = 0, max_len = 0;
1326        int total_files = data->nr;
1327        int width, name_width, count;
1328        const char *reset, *add_c, *del_c;
1329        const char *line_prefix = "";
1330        int extra_shown = 0;
1331        struct strbuf *msg = NULL;
1332
1333        if (data->nr == 0)
1334                return;
1335
1336        if (options->output_prefix) {
1337                msg = options->output_prefix(options, options->output_prefix_data);
1338                line_prefix = msg->buf;
1339        }
1340
1341        width = options->stat_width ? options->stat_width : 80;
1342        name_width = options->stat_name_width ? options->stat_name_width : 50;
1343        count = options->stat_count ? options->stat_count : data->nr;
1344
1345        /* Sanity: give at least 5 columns to the graph,
1346         * but leave at least 10 columns for the name.
1347         */
1348        if (width < 25)
1349                width = 25;
1350        if (name_width < 10)
1351                name_width = 10;
1352        else if (width < name_width + 15)
1353                name_width = width - 15;
1354
1355        /* Find the longest filename and max number of changes */
1356        reset = diff_get_color_opt(options, DIFF_RESET);
1357        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1358        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1359
1360        for (i = 0; (i < count) && (i < data->nr); i++) {
1361                struct diffstat_file *file = data->files[i];
1362                uintmax_t change = file->added + file->deleted;
1363                if (!data->files[i]->is_renamed &&
1364                         (change == 0)) {
1365                        count++; /* not shown == room for one more */
1366                        continue;
1367                }
1368                fill_print_name(file);
1369                len = strlen(file->print_name);
1370                if (max_len < len)
1371                        max_len = len;
1372
1373                if (file->is_binary || file->is_unmerged)
1374                        continue;
1375                if (max_change < change)
1376                        max_change = change;
1377        }
1378        count = i; /* min(count, data->nr) */
1379
1380        /* Compute the width of the graph part;
1381         * 10 is for one blank at the beginning of the line plus
1382         * " | count " between the name and the graph.
1383         *
1384         * From here on, name_width is the width of the name area,
1385         * and width is the width of the graph area.
1386         */
1387        name_width = (name_width < max_len) ? name_width : max_len;
1388        if (width < (name_width + 10) + max_change)
1389                width = width - (name_width + 10);
1390        else
1391                width = max_change;
1392
1393        for (i = 0; i < count; i++) {
1394                const char *prefix = "";
1395                char *name = data->files[i]->print_name;
1396                uintmax_t added = data->files[i]->added;
1397                uintmax_t deleted = data->files[i]->deleted;
1398                int name_len;
1399
1400                if (!data->files[i]->is_renamed &&
1401                         (added + deleted == 0)) {
1402                        total_files--;
1403                        continue;
1404                }
1405                /*
1406                 * "scale" the filename
1407                 */
1408                len = name_width;
1409                name_len = strlen(name);
1410                if (name_width < name_len) {
1411                        char *slash;
1412                        prefix = "...";
1413                        len -= 3;
1414                        name += name_len - len;
1415                        slash = strchr(name, '/');
1416                        if (slash)
1417                                name = slash;
1418                }
1419
1420                if (data->files[i]->is_binary) {
1421                        fprintf(options->file, "%s", line_prefix);
1422                        show_name(options->file, prefix, name, len);
1423                        fprintf(options->file, "  Bin ");
1424                        fprintf(options->file, "%s%"PRIuMAX"%s",
1425                                del_c, deleted, reset);
1426                        fprintf(options->file, " -> ");
1427                        fprintf(options->file, "%s%"PRIuMAX"%s",
1428                                add_c, added, reset);
1429                        fprintf(options->file, " bytes");
1430                        fprintf(options->file, "\n");
1431                        continue;
1432                }
1433                else if (data->files[i]->is_unmerged) {
1434                        fprintf(options->file, "%s", line_prefix);
1435                        show_name(options->file, prefix, name, len);
1436                        fprintf(options->file, "  Unmerged\n");
1437                        continue;
1438                }
1439
1440                /*
1441                 * scale the add/delete
1442                 */
1443                add = added;
1444                del = deleted;
1445                adds += add;
1446                dels += del;
1447
1448                if (width <= max_change) {
1449                        add = scale_linear(add, width, max_change);
1450                        del = scale_linear(del, width, max_change);
1451                }
1452                fprintf(options->file, "%s", line_prefix);
1453                show_name(options->file, prefix, name, len);
1454                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1455                                added + deleted ? " " : "");
1456                show_graph(options->file, '+', add, add_c, reset);
1457                show_graph(options->file, '-', del, del_c, reset);
1458                fprintf(options->file, "\n");
1459        }
1460        for (i = count; i < data->nr; i++) {
1461                uintmax_t added = data->files[i]->added;
1462                uintmax_t deleted = data->files[i]->deleted;
1463                if (!data->files[i]->is_renamed &&
1464                         (added + deleted == 0)) {
1465                        total_files--;
1466                        continue;
1467                }
1468                adds += added;
1469                dels += deleted;
1470                if (!extra_shown)
1471                        fprintf(options->file, "%s ...\n", line_prefix);
1472                extra_shown = 1;
1473        }
1474        fprintf(options->file, "%s", line_prefix);
1475        fprintf(options->file,
1476               " %d files changed, %d insertions(+), %d deletions(-)\n",
1477               total_files, adds, dels);
1478}
1479
1480static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1481{
1482        int i, adds = 0, dels = 0, total_files = data->nr;
1483
1484        if (data->nr == 0)
1485                return;
1486
1487        for (i = 0; i < data->nr; i++) {
1488                if (!data->files[i]->is_binary &&
1489                    !data->files[i]->is_unmerged) {
1490                        int added = data->files[i]->added;
1491                        int deleted= data->files[i]->deleted;
1492                        if (!data->files[i]->is_renamed &&
1493                            (added + deleted == 0)) {
1494                                total_files--;
1495                        } else {
1496                                adds += added;
1497                                dels += deleted;
1498                        }
1499                }
1500        }
1501        if (options->output_prefix) {
1502                struct strbuf *msg = NULL;
1503                msg = options->output_prefix(options,
1504                                options->output_prefix_data);
1505                fprintf(options->file, "%s", msg->buf);
1506        }
1507        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1508               total_files, adds, dels);
1509}
1510
1511static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1512{
1513        int i;
1514
1515        if (data->nr == 0)
1516                return;
1517
1518        for (i = 0; i < data->nr; i++) {
1519                struct diffstat_file *file = data->files[i];
1520
1521                if (options->output_prefix) {
1522                        struct strbuf *msg = NULL;
1523                        msg = options->output_prefix(options,
1524                                        options->output_prefix_data);
1525                        fprintf(options->file, "%s", msg->buf);
1526                }
1527
1528                if (file->is_binary)
1529                        fprintf(options->file, "-\t-\t");
1530                else
1531                        fprintf(options->file,
1532                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1533                                file->added, file->deleted);
1534                if (options->line_termination) {
1535                        fill_print_name(file);
1536                        if (!file->is_renamed)
1537                                write_name_quoted(file->name, options->file,
1538                                                  options->line_termination);
1539                        else {
1540                                fputs(file->print_name, options->file);
1541                                putc(options->line_termination, options->file);
1542                        }
1543                } else {
1544                        if (file->is_renamed) {
1545                                putc('\0', options->file);
1546                                write_name_quoted(file->from_name, options->file, '\0');
1547                        }
1548                        write_name_quoted(file->name, options->file, '\0');
1549                }
1550        }
1551}
1552
1553struct dirstat_file {
1554        const char *name;
1555        unsigned long changed;
1556};
1557
1558struct dirstat_dir {
1559        struct dirstat_file *files;
1560        int alloc, nr, permille, cumulative;
1561};
1562
1563static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1564                unsigned long changed, const char *base, int baselen)
1565{
1566        unsigned long this_dir = 0;
1567        unsigned int sources = 0;
1568        const char *line_prefix = "";
1569        struct strbuf *msg = NULL;
1570
1571        if (opt->output_prefix) {
1572                msg = opt->output_prefix(opt, opt->output_prefix_data);
1573                line_prefix = msg->buf;
1574        }
1575
1576        while (dir->nr) {
1577                struct dirstat_file *f = dir->files;
1578                int namelen = strlen(f->name);
1579                unsigned long this;
1580                char *slash;
1581
1582                if (namelen < baselen)
1583                        break;
1584                if (memcmp(f->name, base, baselen))
1585                        break;
1586                slash = strchr(f->name + baselen, '/');
1587                if (slash) {
1588                        int newbaselen = slash + 1 - f->name;
1589                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1590                        sources++;
1591                } else {
1592                        this = f->changed;
1593                        dir->files++;
1594                        dir->nr--;
1595                        sources += 2;
1596                }
1597                this_dir += this;
1598        }
1599
1600        /*
1601         * We don't report dirstat's for
1602         *  - the top level
1603         *  - or cases where everything came from a single directory
1604         *    under this directory (sources == 1).
1605         */
1606        if (baselen && sources != 1) {
1607                if (this_dir) {
1608                        int permille = this_dir * 1000 / changed;
1609                        if (permille >= dir->permille) {
1610                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1611                                        permille / 10, permille % 10, baselen, base);
1612                                if (!dir->cumulative)
1613                                        return 0;
1614                        }
1615                }
1616        }
1617        return this_dir;
1618}
1619
1620static int dirstat_compare(const void *_a, const void *_b)
1621{
1622        const struct dirstat_file *a = _a;
1623        const struct dirstat_file *b = _b;
1624        return strcmp(a->name, b->name);
1625}
1626
1627static void show_dirstat(struct diff_options *options)
1628{
1629        int i;
1630        unsigned long changed;
1631        struct dirstat_dir dir;
1632        struct diff_queue_struct *q = &diff_queued_diff;
1633
1634        dir.files = NULL;
1635        dir.alloc = 0;
1636        dir.nr = 0;
1637        dir.permille = options->dirstat_permille;
1638        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1639
1640        changed = 0;
1641        for (i = 0; i < q->nr; i++) {
1642                struct diff_filepair *p = q->queue[i];
1643                const char *name;
1644                unsigned long copied, added, damage;
1645                int content_changed;
1646
1647                name = p->two->path ? p->two->path : p->one->path;
1648
1649                if (p->one->sha1_valid && p->two->sha1_valid)
1650                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1651                else
1652                        content_changed = 1;
1653
1654                if (!content_changed) {
1655                        /*
1656                         * The SHA1 has not changed, so pre-/post-content is
1657                         * identical. We can therefore skip looking at the
1658                         * file contents altogether.
1659                         */
1660                        damage = 0;
1661                        goto found_damage;
1662                }
1663
1664                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1665                        /*
1666                         * In --dirstat-by-file mode, we don't really need to
1667                         * look at the actual file contents at all.
1668                         * The fact that the SHA1 changed is enough for us to
1669                         * add this file to the list of results
1670                         * (with each file contributing equal damage).
1671                         */
1672                        damage = 1;
1673                        goto found_damage;
1674                }
1675
1676                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1677                        diff_populate_filespec(p->one, 0);
1678                        diff_populate_filespec(p->two, 0);
1679                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1680                                               &copied, &added);
1681                        diff_free_filespec_data(p->one);
1682                        diff_free_filespec_data(p->two);
1683                } else if (DIFF_FILE_VALID(p->one)) {
1684                        diff_populate_filespec(p->one, 1);
1685                        copied = added = 0;
1686                        diff_free_filespec_data(p->one);
1687                } else if (DIFF_FILE_VALID(p->two)) {
1688                        diff_populate_filespec(p->two, 1);
1689                        copied = 0;
1690                        added = p->two->size;
1691                        diff_free_filespec_data(p->two);
1692                } else
1693                        continue;
1694
1695                /*
1696                 * Original minus copied is the removed material,
1697                 * added is the new material.  They are both damages
1698                 * made to the preimage.
1699                 * If the resulting damage is zero, we know that
1700                 * diffcore_count_changes() considers the two entries to
1701                 * be identical, but since content_changed is true, we
1702                 * know that there must have been _some_ kind of change,
1703                 * so we force all entries to have damage > 0.
1704                 */
1705                damage = (p->one->size - copied) + added;
1706                if (!damage)
1707                        damage = 1;
1708
1709found_damage:
1710                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1711                dir.files[dir.nr].name = name;
1712                dir.files[dir.nr].changed = damage;
1713                changed += damage;
1714                dir.nr++;
1715        }
1716
1717        /* This can happen even with many files, if everything was renames */
1718        if (!changed)
1719                return;
1720
1721        /* Show all directories with more than x% of the changes */
1722        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1723        gather_dirstat(options, &dir, changed, "", 0);
1724}
1725
1726static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1727{
1728        int i;
1729        unsigned long changed;
1730        struct dirstat_dir dir;
1731
1732        if (data->nr == 0)
1733                return;
1734
1735        dir.files = NULL;
1736        dir.alloc = 0;
1737        dir.nr = 0;
1738        dir.permille = options->dirstat_permille;
1739        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1740
1741        changed = 0;
1742        for (i = 0; i < data->nr; i++) {
1743                struct diffstat_file *file = data->files[i];
1744                unsigned long damage = file->added + file->deleted;
1745                if (file->is_binary)
1746                        /*
1747                         * binary files counts bytes, not lines. Must find some
1748                         * way to normalize binary bytes vs. textual lines.
1749                         * The following heuristic assumes that there are 64
1750                         * bytes per "line".
1751                         * This is stupid and ugly, but very cheap...
1752                         */
1753                        damage = (damage + 63) / 64;
1754                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1755                dir.files[dir.nr].name = file->name;
1756                dir.files[dir.nr].changed = damage;
1757                changed += damage;
1758                dir.nr++;
1759        }
1760
1761        /* This can happen even with many files, if everything was renames */
1762        if (!changed)
1763                return;
1764
1765        /* Show all directories with more than x% of the changes */
1766        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1767        gather_dirstat(options, &dir, changed, "", 0);
1768}
1769
1770static void free_diffstat_info(struct diffstat_t *diffstat)
1771{
1772        int i;
1773        for (i = 0; i < diffstat->nr; i++) {
1774                struct diffstat_file *f = diffstat->files[i];
1775                if (f->name != f->print_name)
1776                        free(f->print_name);
1777                free(f->name);
1778                free(f->from_name);
1779                free(f);
1780        }
1781        free(diffstat->files);
1782}
1783
1784struct checkdiff_t {
1785        const char *filename;
1786        int lineno;
1787        int conflict_marker_size;
1788        struct diff_options *o;
1789        unsigned ws_rule;
1790        unsigned status;
1791};
1792
1793static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1794{
1795        char firstchar;
1796        int cnt;
1797
1798        if (len < marker_size + 1)
1799                return 0;
1800        firstchar = line[0];
1801        switch (firstchar) {
1802        case '=': case '>': case '<': case '|':
1803                break;
1804        default:
1805                return 0;
1806        }
1807        for (cnt = 1; cnt < marker_size; cnt++)
1808                if (line[cnt] != firstchar)
1809                        return 0;
1810        /* line[1] thru line[marker_size-1] are same as firstchar */
1811        if (len < marker_size + 1 || !isspace(line[marker_size]))
1812                return 0;
1813        return 1;
1814}
1815
1816static void checkdiff_consume(void *priv, char *line, unsigned long len)
1817{
1818        struct checkdiff_t *data = priv;
1819        int marker_size = data->conflict_marker_size;
1820        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1821        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1822        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1823        char *err;
1824        char *line_prefix = "";
1825        struct strbuf *msgbuf;
1826
1827        assert(data->o);
1828        if (data->o->output_prefix) {
1829                msgbuf = data->o->output_prefix(data->o,
1830                        data->o->output_prefix_data);
1831                line_prefix = msgbuf->buf;
1832        }
1833
1834        if (line[0] == '+') {
1835                unsigned bad;
1836                data->lineno++;
1837                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1838                        data->status |= 1;
1839                        fprintf(data->o->file,
1840                                "%s%s:%d: leftover conflict marker\n",
1841                                line_prefix, data->filename, data->lineno);
1842                }
1843                bad = ws_check(line + 1, len - 1, data->ws_rule);
1844                if (!bad)
1845                        return;
1846                data->status |= bad;
1847                err = whitespace_error_string(bad);
1848                fprintf(data->o->file, "%s%s:%d: %s.\n",
1849                        line_prefix, data->filename, data->lineno, err);
1850                free(err);
1851                emit_line(data->o, set, reset, line, 1);
1852                ws_check_emit(line + 1, len - 1, data->ws_rule,
1853                              data->o->file, set, reset, ws);
1854        } else if (line[0] == ' ') {
1855                data->lineno++;
1856        } else if (line[0] == '@') {
1857                char *plus = strchr(line, '+');
1858                if (plus)
1859                        data->lineno = strtol(plus, NULL, 10) - 1;
1860                else
1861                        die("invalid diff");
1862        }
1863}
1864
1865static unsigned char *deflate_it(char *data,
1866                                 unsigned long size,
1867                                 unsigned long *result_size)
1868{
1869        int bound;
1870        unsigned char *deflated;
1871        git_zstream stream;
1872
1873        memset(&stream, 0, sizeof(stream));
1874        git_deflate_init(&stream, zlib_compression_level);
1875        bound = git_deflate_bound(&stream, size);
1876        deflated = xmalloc(bound);
1877        stream.next_out = deflated;
1878        stream.avail_out = bound;
1879
1880        stream.next_in = (unsigned char *)data;
1881        stream.avail_in = size;
1882        while (git_deflate(&stream, Z_FINISH) == Z_OK)
1883                ; /* nothing */
1884        git_deflate_end(&stream);
1885        *result_size = stream.total_out;
1886        return deflated;
1887}
1888
1889static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1890{
1891        void *cp;
1892        void *delta;
1893        void *deflated;
1894        void *data;
1895        unsigned long orig_size;
1896        unsigned long delta_size;
1897        unsigned long deflate_size;
1898        unsigned long data_size;
1899
1900        /* We could do deflated delta, or we could do just deflated two,
1901         * whichever is smaller.
1902         */
1903        delta = NULL;
1904        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1905        if (one->size && two->size) {
1906                delta = diff_delta(one->ptr, one->size,
1907                                   two->ptr, two->size,
1908                                   &delta_size, deflate_size);
1909                if (delta) {
1910                        void *to_free = delta;
1911                        orig_size = delta_size;
1912                        delta = deflate_it(delta, delta_size, &delta_size);
1913                        free(to_free);
1914                }
1915        }
1916
1917        if (delta && delta_size < deflate_size) {
1918                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1919                free(deflated);
1920                data = delta;
1921                data_size = delta_size;
1922        }
1923        else {
1924                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1925                free(delta);
1926                data = deflated;
1927                data_size = deflate_size;
1928        }
1929
1930        /* emit data encoded in base85 */
1931        cp = data;
1932        while (data_size) {
1933                int bytes = (52 < data_size) ? 52 : data_size;
1934                char line[70];
1935                data_size -= bytes;
1936                if (bytes <= 26)
1937                        line[0] = bytes + 'A' - 1;
1938                else
1939                        line[0] = bytes - 26 + 'a' - 1;
1940                encode_85(line + 1, cp, bytes);
1941                cp = (char *) cp + bytes;
1942                fprintf(file, "%s", prefix);
1943                fputs(line, file);
1944                fputc('\n', file);
1945        }
1946        fprintf(file, "%s\n", prefix);
1947        free(data);
1948}
1949
1950static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1951{
1952        fprintf(file, "%sGIT binary patch\n", prefix);
1953        emit_binary_diff_body(file, one, two, prefix);
1954        emit_binary_diff_body(file, two, one, prefix);
1955}
1956
1957static void diff_filespec_load_driver(struct diff_filespec *one)
1958{
1959        /* Use already-loaded driver */
1960        if (one->driver)
1961                return;
1962
1963        if (S_ISREG(one->mode))
1964                one->driver = userdiff_find_by_path(one->path);
1965
1966        /* Fallback to default settings */
1967        if (!one->driver)
1968                one->driver = userdiff_find_by_name("default");
1969}
1970
1971int diff_filespec_is_binary(struct diff_filespec *one)
1972{
1973        if (one->is_binary == -1) {
1974                diff_filespec_load_driver(one);
1975                if (one->driver->binary != -1)
1976                        one->is_binary = one->driver->binary;
1977                else {
1978                        if (!one->data && DIFF_FILE_VALID(one))
1979                                diff_populate_filespec(one, 0);
1980                        if (one->data)
1981                                one->is_binary = buffer_is_binary(one->data,
1982                                                one->size);
1983                        if (one->is_binary == -1)
1984                                one->is_binary = 0;
1985                }
1986        }
1987        return one->is_binary;
1988}
1989
1990static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1991{
1992        diff_filespec_load_driver(one);
1993        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1994}
1995
1996static const char *userdiff_word_regex(struct diff_filespec *one)
1997{
1998        diff_filespec_load_driver(one);
1999        return one->driver->word_regex;
2000}
2001
2002void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2003{
2004        if (!options->a_prefix)
2005                options->a_prefix = a;
2006        if (!options->b_prefix)
2007                options->b_prefix = b;
2008}
2009
2010struct userdiff_driver *get_textconv(struct diff_filespec *one)
2011{
2012        if (!DIFF_FILE_VALID(one))
2013                return NULL;
2014
2015        diff_filespec_load_driver(one);
2016        return userdiff_get_textconv(one->driver);
2017}
2018
2019static void builtin_diff(const char *name_a,
2020                         const char *name_b,
2021                         struct diff_filespec *one,
2022                         struct diff_filespec *two,
2023                         const char *xfrm_msg,
2024                         int must_show_header,
2025                         struct diff_options *o,
2026                         int complete_rewrite)
2027{
2028        mmfile_t mf1, mf2;
2029        const char *lbl[2];
2030        char *a_one, *b_two;
2031        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2032        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2033        const char *a_prefix, *b_prefix;
2034        struct userdiff_driver *textconv_one = NULL;
2035        struct userdiff_driver *textconv_two = NULL;
2036        struct strbuf header = STRBUF_INIT;
2037        struct strbuf *msgbuf;
2038        char *line_prefix = "";
2039
2040        if (o->output_prefix) {
2041                msgbuf = o->output_prefix(o, o->output_prefix_data);
2042                line_prefix = msgbuf->buf;
2043        }
2044
2045        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2046                        (!one->mode || S_ISGITLINK(one->mode)) &&
2047                        (!two->mode || S_ISGITLINK(two->mode))) {
2048                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2049                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2050                show_submodule_summary(o->file, one ? one->path : two->path,
2051                                one->sha1, two->sha1, two->dirty_submodule,
2052                                del, add, reset);
2053                return;
2054        }
2055
2056        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2057                textconv_one = get_textconv(one);
2058                textconv_two = get_textconv(two);
2059        }
2060
2061        diff_set_mnemonic_prefix(o, "a/", "b/");
2062        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2063                a_prefix = o->b_prefix;
2064                b_prefix = o->a_prefix;
2065        } else {
2066                a_prefix = o->a_prefix;
2067                b_prefix = o->b_prefix;
2068        }
2069
2070        /* Never use a non-valid filename anywhere if at all possible */
2071        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2072        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2073
2074        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2075        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2076        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2077        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2078        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2079        if (lbl[0][0] == '/') {
2080                /* /dev/null */
2081                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2082                if (xfrm_msg)
2083                        strbuf_addstr(&header, xfrm_msg);
2084                must_show_header = 1;
2085        }
2086        else if (lbl[1][0] == '/') {
2087                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2088                if (xfrm_msg)
2089                        strbuf_addstr(&header, xfrm_msg);
2090                must_show_header = 1;
2091        }
2092        else {
2093                if (one->mode != two->mode) {
2094                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2095                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2096                        must_show_header = 1;
2097                }
2098                if (xfrm_msg)
2099                        strbuf_addstr(&header, xfrm_msg);
2100
2101                /*
2102                 * we do not run diff between different kind
2103                 * of objects.
2104                 */
2105                if ((one->mode ^ two->mode) & S_IFMT)
2106                        goto free_ab_and_return;
2107                if (complete_rewrite &&
2108                    (textconv_one || !diff_filespec_is_binary(one)) &&
2109                    (textconv_two || !diff_filespec_is_binary(two))) {
2110                        fprintf(o->file, "%s", header.buf);
2111                        strbuf_reset(&header);
2112                        emit_rewrite_diff(name_a, name_b, one, two,
2113                                                textconv_one, textconv_two, o);
2114                        o->found_changes = 1;
2115                        goto free_ab_and_return;
2116                }
2117        }
2118
2119        if (o->irreversible_delete && lbl[1][0] == '/') {
2120                fprintf(o->file, "%s", header.buf);
2121                strbuf_reset(&header);
2122                goto free_ab_and_return;
2123        } else if (!DIFF_OPT_TST(o, TEXT) &&
2124            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2125              (!textconv_two && diff_filespec_is_binary(two)) )) {
2126                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2127                        die("unable to read files to diff");
2128                /* Quite common confusing case */
2129                if (mf1.size == mf2.size &&
2130                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2131                        if (must_show_header)
2132                                fprintf(o->file, "%s", header.buf);
2133                        goto free_ab_and_return;
2134                }
2135                fprintf(o->file, "%s", header.buf);
2136                strbuf_reset(&header);
2137                if (DIFF_OPT_TST(o, BINARY))
2138                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2139                else
2140                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2141                                line_prefix, lbl[0], lbl[1]);
2142                o->found_changes = 1;
2143        } else {
2144                /* Crazy xdl interfaces.. */
2145                const char *diffopts = getenv("GIT_DIFF_OPTS");
2146                xpparam_t xpp;
2147                xdemitconf_t xecfg;
2148                struct emit_callback ecbdata;
2149                const struct userdiff_funcname *pe;
2150
2151                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2152                        fprintf(o->file, "%s", header.buf);
2153                        strbuf_reset(&header);
2154                }
2155
2156                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2157                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2158
2159                pe = diff_funcname_pattern(one);
2160                if (!pe)
2161                        pe = diff_funcname_pattern(two);
2162
2163                memset(&xpp, 0, sizeof(xpp));
2164                memset(&xecfg, 0, sizeof(xecfg));
2165                memset(&ecbdata, 0, sizeof(ecbdata));
2166                ecbdata.label_path = lbl;
2167                ecbdata.color_diff = want_color(o->use_color);
2168                ecbdata.found_changesp = &o->found_changes;
2169                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2170                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2171                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2172                ecbdata.opt = o;
2173                ecbdata.header = header.len ? &header : NULL;
2174                xpp.flags = o->xdl_opts;
2175                xecfg.ctxlen = o->context;
2176                xecfg.interhunkctxlen = o->interhunkcontext;
2177                xecfg.flags = XDL_EMIT_FUNCNAMES;
2178                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2179                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2180                if (pe)
2181                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2182                if (!diffopts)
2183                        ;
2184                else if (!prefixcmp(diffopts, "--unified="))
2185                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2186                else if (!prefixcmp(diffopts, "-u"))
2187                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2188                if (o->word_diff) {
2189                        int i;
2190
2191                        ecbdata.diff_words =
2192                                xcalloc(1, sizeof(struct diff_words_data));
2193                        ecbdata.diff_words->type = o->word_diff;
2194                        ecbdata.diff_words->opt = o;
2195                        if (!o->word_regex)
2196                                o->word_regex = userdiff_word_regex(one);
2197                        if (!o->word_regex)
2198                                o->word_regex = userdiff_word_regex(two);
2199                        if (!o->word_regex)
2200                                o->word_regex = diff_word_regex_cfg;
2201                        if (o->word_regex) {
2202                                ecbdata.diff_words->word_regex = (regex_t *)
2203                                        xmalloc(sizeof(regex_t));
2204                                if (regcomp(ecbdata.diff_words->word_regex,
2205                                                o->word_regex,
2206                                                REG_EXTENDED | REG_NEWLINE))
2207                                        die ("Invalid regular expression: %s",
2208                                                        o->word_regex);
2209                        }
2210                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2211                                if (o->word_diff == diff_words_styles[i].type) {
2212                                        ecbdata.diff_words->style =
2213                                                &diff_words_styles[i];
2214                                        break;
2215                                }
2216                        }
2217                        if (want_color(o->use_color)) {
2218                                struct diff_words_style *st = ecbdata.diff_words->style;
2219                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2220                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2221                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2222                        }
2223                }
2224                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2225                              &xpp, &xecfg);
2226                if (o->word_diff)
2227                        free_diff_words_data(&ecbdata);
2228                if (textconv_one)
2229                        free(mf1.ptr);
2230                if (textconv_two)
2231                        free(mf2.ptr);
2232                xdiff_clear_find_func(&xecfg);
2233        }
2234
2235 free_ab_and_return:
2236        strbuf_release(&header);
2237        diff_free_filespec_data(one);
2238        diff_free_filespec_data(two);
2239        free(a_one);
2240        free(b_two);
2241        return;
2242}
2243
2244static void builtin_diffstat(const char *name_a, const char *name_b,
2245                             struct diff_filespec *one,
2246                             struct diff_filespec *two,
2247                             struct diffstat_t *diffstat,
2248                             struct diff_options *o,
2249                             int complete_rewrite)
2250{
2251        mmfile_t mf1, mf2;
2252        struct diffstat_file *data;
2253
2254        data = diffstat_add(diffstat, name_a, name_b);
2255
2256        if (!one || !two) {
2257                data->is_unmerged = 1;
2258                return;
2259        }
2260
2261        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2262                data->is_binary = 1;
2263                data->added = diff_filespec_size(two);
2264                data->deleted = diff_filespec_size(one);
2265        }
2266
2267        else if (complete_rewrite) {
2268                diff_populate_filespec(one, 0);
2269                diff_populate_filespec(two, 0);
2270                data->deleted = count_lines(one->data, one->size);
2271                data->added = count_lines(two->data, two->size);
2272        }
2273
2274        else {
2275                /* Crazy xdl interfaces.. */
2276                xpparam_t xpp;
2277                xdemitconf_t xecfg;
2278
2279                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2280                        die("unable to read files to diff");
2281
2282                memset(&xpp, 0, sizeof(xpp));
2283                memset(&xecfg, 0, sizeof(xecfg));
2284                xpp.flags = o->xdl_opts;
2285                xecfg.ctxlen = o->context;
2286                xecfg.interhunkctxlen = o->interhunkcontext;
2287                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2288                              &xpp, &xecfg);
2289        }
2290
2291        diff_free_filespec_data(one);
2292        diff_free_filespec_data(two);
2293}
2294
2295static void builtin_checkdiff(const char *name_a, const char *name_b,
2296                              const char *attr_path,
2297                              struct diff_filespec *one,
2298                              struct diff_filespec *two,
2299                              struct diff_options *o)
2300{
2301        mmfile_t mf1, mf2;
2302        struct checkdiff_t data;
2303
2304        if (!two)
2305                return;
2306
2307        memset(&data, 0, sizeof(data));
2308        data.filename = name_b ? name_b : name_a;
2309        data.lineno = 0;
2310        data.o = o;
2311        data.ws_rule = whitespace_rule(attr_path);
2312        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2313
2314        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2315                die("unable to read files to diff");
2316
2317        /*
2318         * All the other codepaths check both sides, but not checking
2319         * the "old" side here is deliberate.  We are checking the newly
2320         * introduced changes, and as long as the "new" side is text, we
2321         * can and should check what it introduces.
2322         */
2323        if (diff_filespec_is_binary(two))
2324                goto free_and_return;
2325        else {
2326                /* Crazy xdl interfaces.. */
2327                xpparam_t xpp;
2328                xdemitconf_t xecfg;
2329
2330                memset(&xpp, 0, sizeof(xpp));
2331                memset(&xecfg, 0, sizeof(xecfg));
2332                xecfg.ctxlen = 1; /* at least one context line */
2333                xpp.flags = 0;
2334                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2335                              &xpp, &xecfg);
2336
2337                if (data.ws_rule & WS_BLANK_AT_EOF) {
2338                        struct emit_callback ecbdata;
2339                        int blank_at_eof;
2340
2341                        ecbdata.ws_rule = data.ws_rule;
2342                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2343                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2344
2345                        if (blank_at_eof) {
2346                                static char *err;
2347                                if (!err)
2348                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2349                                fprintf(o->file, "%s:%d: %s.\n",
2350                                        data.filename, blank_at_eof, err);
2351                                data.status = 1; /* report errors */
2352                        }
2353                }
2354        }
2355 free_and_return:
2356        diff_free_filespec_data(one);
2357        diff_free_filespec_data(two);
2358        if (data.status)
2359                DIFF_OPT_SET(o, CHECK_FAILED);
2360}
2361
2362struct diff_filespec *alloc_filespec(const char *path)
2363{
2364        int namelen = strlen(path);
2365        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2366
2367        memset(spec, 0, sizeof(*spec));
2368        spec->path = (char *)(spec + 1);
2369        memcpy(spec->path, path, namelen+1);
2370        spec->count = 1;
2371        spec->is_binary = -1;
2372        return spec;
2373}
2374
2375void free_filespec(struct diff_filespec *spec)
2376{
2377        if (!--spec->count) {
2378                diff_free_filespec_data(spec);
2379                free(spec);
2380        }
2381}
2382
2383void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2384                   unsigned short mode)
2385{
2386        if (mode) {
2387                spec->mode = canon_mode(mode);
2388                hashcpy(spec->sha1, sha1);
2389                spec->sha1_valid = !is_null_sha1(sha1);
2390        }
2391}
2392
2393/*
2394 * Given a name and sha1 pair, if the index tells us the file in
2395 * the work tree has that object contents, return true, so that
2396 * prepare_temp_file() does not have to inflate and extract.
2397 */
2398static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2399{
2400        struct cache_entry *ce;
2401        struct stat st;
2402        int pos, len;
2403
2404        /*
2405         * We do not read the cache ourselves here, because the
2406         * benchmark with my previous version that always reads cache
2407         * shows that it makes things worse for diff-tree comparing
2408         * two linux-2.6 kernel trees in an already checked out work
2409         * tree.  This is because most diff-tree comparisons deal with
2410         * only a small number of files, while reading the cache is
2411         * expensive for a large project, and its cost outweighs the
2412         * savings we get by not inflating the object to a temporary
2413         * file.  Practically, this code only helps when we are used
2414         * by diff-cache --cached, which does read the cache before
2415         * calling us.
2416         */
2417        if (!active_cache)
2418                return 0;
2419
2420        /* We want to avoid the working directory if our caller
2421         * doesn't need the data in a normal file, this system
2422         * is rather slow with its stat/open/mmap/close syscalls,
2423         * and the object is contained in a pack file.  The pack
2424         * is probably already open and will be faster to obtain
2425         * the data through than the working directory.  Loose
2426         * objects however would tend to be slower as they need
2427         * to be individually opened and inflated.
2428         */
2429        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2430                return 0;
2431
2432        len = strlen(name);
2433        pos = cache_name_pos(name, len);
2434        if (pos < 0)
2435                return 0;
2436        ce = active_cache[pos];
2437
2438        /*
2439         * This is not the sha1 we are looking for, or
2440         * unreusable because it is not a regular file.
2441         */
2442        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2443                return 0;
2444
2445        /*
2446         * If ce is marked as "assume unchanged", there is no
2447         * guarantee that work tree matches what we are looking for.
2448         */
2449        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2450                return 0;
2451
2452        /*
2453         * If ce matches the file in the work tree, we can reuse it.
2454         */
2455        if (ce_uptodate(ce) ||
2456            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2457                return 1;
2458
2459        return 0;
2460}
2461
2462static int populate_from_stdin(struct diff_filespec *s)
2463{
2464        struct strbuf buf = STRBUF_INIT;
2465        size_t size = 0;
2466
2467        if (strbuf_read(&buf, 0, 0) < 0)
2468                return error("error while reading from stdin %s",
2469                                     strerror(errno));
2470
2471        s->should_munmap = 0;
2472        s->data = strbuf_detach(&buf, &size);
2473        s->size = size;
2474        s->should_free = 1;
2475        return 0;
2476}
2477
2478static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2479{
2480        int len;
2481        char *data = xmalloc(100), *dirty = "";
2482
2483        /* Are we looking at the work tree? */
2484        if (s->dirty_submodule)
2485                dirty = "-dirty";
2486
2487        len = snprintf(data, 100,
2488                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2489        s->data = data;
2490        s->size = len;
2491        s->should_free = 1;
2492        if (size_only) {
2493                s->data = NULL;
2494                free(data);
2495        }
2496        return 0;
2497}
2498
2499/*
2500 * While doing rename detection and pickaxe operation, we may need to
2501 * grab the data for the blob (or file) for our own in-core comparison.
2502 * diff_filespec has data and size fields for this purpose.
2503 */
2504int diff_populate_filespec(struct diff_filespec *s, int size_only)
2505{
2506        int err = 0;
2507        if (!DIFF_FILE_VALID(s))
2508                die("internal error: asking to populate invalid file.");
2509        if (S_ISDIR(s->mode))
2510                return -1;
2511
2512        if (s->data)
2513                return 0;
2514
2515        if (size_only && 0 < s->size)
2516                return 0;
2517
2518        if (S_ISGITLINK(s->mode))
2519                return diff_populate_gitlink(s, size_only);
2520
2521        if (!s->sha1_valid ||
2522            reuse_worktree_file(s->path, s->sha1, 0)) {
2523                struct strbuf buf = STRBUF_INIT;
2524                struct stat st;
2525                int fd;
2526
2527                if (!strcmp(s->path, "-"))
2528                        return populate_from_stdin(s);
2529
2530                if (lstat(s->path, &st) < 0) {
2531                        if (errno == ENOENT) {
2532                        err_empty:
2533                                err = -1;
2534                        empty:
2535                                s->data = (char *)"";
2536                                s->size = 0;
2537                                return err;
2538                        }
2539                }
2540                s->size = xsize_t(st.st_size);
2541                if (!s->size)
2542                        goto empty;
2543                if (S_ISLNK(st.st_mode)) {
2544                        struct strbuf sb = STRBUF_INIT;
2545
2546                        if (strbuf_readlink(&sb, s->path, s->size))
2547                                goto err_empty;
2548                        s->size = sb.len;
2549                        s->data = strbuf_detach(&sb, NULL);
2550                        s->should_free = 1;
2551                        return 0;
2552                }
2553                if (size_only)
2554                        return 0;
2555                fd = open(s->path, O_RDONLY);
2556                if (fd < 0)
2557                        goto err_empty;
2558                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2559                close(fd);
2560                s->should_munmap = 1;
2561
2562                /*
2563                 * Convert from working tree format to canonical git format
2564                 */
2565                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2566                        size_t size = 0;
2567                        munmap(s->data, s->size);
2568                        s->should_munmap = 0;
2569                        s->data = strbuf_detach(&buf, &size);
2570                        s->size = size;
2571                        s->should_free = 1;
2572                }
2573        }
2574        else {
2575                enum object_type type;
2576                if (size_only) {
2577                        type = sha1_object_info(s->sha1, &s->size);
2578                        if (type < 0)
2579                                die("unable to read %s", sha1_to_hex(s->sha1));
2580                } else {
2581                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2582                        if (!s->data)
2583                                die("unable to read %s", sha1_to_hex(s->sha1));
2584                        s->should_free = 1;
2585                }
2586        }
2587        return 0;
2588}
2589
2590void diff_free_filespec_blob(struct diff_filespec *s)
2591{
2592        if (s->should_free)
2593                free(s->data);
2594        else if (s->should_munmap)
2595                munmap(s->data, s->size);
2596
2597        if (s->should_free || s->should_munmap) {
2598                s->should_free = s->should_munmap = 0;
2599                s->data = NULL;
2600        }
2601}
2602
2603void diff_free_filespec_data(struct diff_filespec *s)
2604{
2605        diff_free_filespec_blob(s);
2606        free(s->cnt_data);
2607        s->cnt_data = NULL;
2608}
2609
2610static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2611                           void *blob,
2612                           unsigned long size,
2613                           const unsigned char *sha1,
2614                           int mode)
2615{
2616        int fd;
2617        struct strbuf buf = STRBUF_INIT;
2618        struct strbuf template = STRBUF_INIT;
2619        char *path_dup = xstrdup(path);
2620        const char *base = basename(path_dup);
2621
2622        /* Generate "XXXXXX_basename.ext" */
2623        strbuf_addstr(&template, "XXXXXX_");
2624        strbuf_addstr(&template, base);
2625
2626        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2627                        strlen(base) + 1);
2628        if (fd < 0)
2629                die_errno("unable to create temp-file");
2630        if (convert_to_working_tree(path,
2631                        (const char *)blob, (size_t)size, &buf)) {
2632                blob = buf.buf;
2633                size = buf.len;
2634        }
2635        if (write_in_full(fd, blob, size) != size)
2636                die_errno("unable to write temp-file");
2637        close(fd);
2638        temp->name = temp->tmp_path;
2639        strcpy(temp->hex, sha1_to_hex(sha1));
2640        temp->hex[40] = 0;
2641        sprintf(temp->mode, "%06o", mode);
2642        strbuf_release(&buf);
2643        strbuf_release(&template);
2644        free(path_dup);
2645}
2646
2647static struct diff_tempfile *prepare_temp_file(const char *name,
2648                struct diff_filespec *one)
2649{
2650        struct diff_tempfile *temp = claim_diff_tempfile();
2651
2652        if (!DIFF_FILE_VALID(one)) {
2653        not_a_valid_file:
2654                /* A '-' entry produces this for file-2, and
2655                 * a '+' entry produces this for file-1.
2656                 */
2657                temp->name = "/dev/null";
2658                strcpy(temp->hex, ".");
2659                strcpy(temp->mode, ".");
2660                return temp;
2661        }
2662
2663        if (!remove_tempfile_installed) {
2664                atexit(remove_tempfile);
2665                sigchain_push_common(remove_tempfile_on_signal);
2666                remove_tempfile_installed = 1;
2667        }
2668
2669        if (!one->sha1_valid ||
2670            reuse_worktree_file(name, one->sha1, 1)) {
2671                struct stat st;
2672                if (lstat(name, &st) < 0) {
2673                        if (errno == ENOENT)
2674                                goto not_a_valid_file;
2675                        die_errno("stat(%s)", name);
2676                }
2677                if (S_ISLNK(st.st_mode)) {
2678                        struct strbuf sb = STRBUF_INIT;
2679                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2680                                die_errno("readlink(%s)", name);
2681                        prep_temp_blob(name, temp, sb.buf, sb.len,
2682                                       (one->sha1_valid ?
2683                                        one->sha1 : null_sha1),
2684                                       (one->sha1_valid ?
2685                                        one->mode : S_IFLNK));
2686                        strbuf_release(&sb);
2687                }
2688                else {
2689                        /* we can borrow from the file in the work tree */
2690                        temp->name = name;
2691                        if (!one->sha1_valid)
2692                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2693                        else
2694                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2695                        /* Even though we may sometimes borrow the
2696                         * contents from the work tree, we always want
2697                         * one->mode.  mode is trustworthy even when
2698                         * !(one->sha1_valid), as long as
2699                         * DIFF_FILE_VALID(one).
2700                         */
2701                        sprintf(temp->mode, "%06o", one->mode);
2702                }
2703                return temp;
2704        }
2705        else {
2706                if (diff_populate_filespec(one, 0))
2707                        die("cannot read data blob for %s", one->path);
2708                prep_temp_blob(name, temp, one->data, one->size,
2709                               one->sha1, one->mode);
2710        }
2711        return temp;
2712}
2713
2714/* An external diff command takes:
2715 *
2716 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2717 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2718 *
2719 */
2720static void run_external_diff(const char *pgm,
2721                              const char *name,
2722                              const char *other,
2723                              struct diff_filespec *one,
2724                              struct diff_filespec *two,
2725                              const char *xfrm_msg,
2726                              int complete_rewrite)
2727{
2728        const char *spawn_arg[10];
2729        int retval;
2730        const char **arg = &spawn_arg[0];
2731
2732        if (one && two) {
2733                struct diff_tempfile *temp_one, *temp_two;
2734                const char *othername = (other ? other : name);
2735                temp_one = prepare_temp_file(name, one);
2736                temp_two = prepare_temp_file(othername, two);
2737                *arg++ = pgm;
2738                *arg++ = name;
2739                *arg++ = temp_one->name;
2740                *arg++ = temp_one->hex;
2741                *arg++ = temp_one->mode;
2742                *arg++ = temp_two->name;
2743                *arg++ = temp_two->hex;
2744                *arg++ = temp_two->mode;
2745                if (other) {
2746                        *arg++ = other;
2747                        *arg++ = xfrm_msg;
2748                }
2749        } else {
2750                *arg++ = pgm;
2751                *arg++ = name;
2752        }
2753        *arg = NULL;
2754        fflush(NULL);
2755        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2756        remove_tempfile();
2757        if (retval) {
2758                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2759                exit(1);
2760        }
2761}
2762
2763static int similarity_index(struct diff_filepair *p)
2764{
2765        return p->score * 100 / MAX_SCORE;
2766}
2767
2768static void fill_metainfo(struct strbuf *msg,
2769                          const char *name,
2770                          const char *other,
2771                          struct diff_filespec *one,
2772                          struct diff_filespec *two,
2773                          struct diff_options *o,
2774                          struct diff_filepair *p,
2775                          int *must_show_header,
2776                          int use_color)
2777{
2778        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2779        const char *reset = diff_get_color(use_color, DIFF_RESET);
2780        struct strbuf *msgbuf;
2781        char *line_prefix = "";
2782
2783        *must_show_header = 1;
2784        if (o->output_prefix) {
2785                msgbuf = o->output_prefix(o, o->output_prefix_data);
2786                line_prefix = msgbuf->buf;
2787        }
2788        strbuf_init(msg, PATH_MAX * 2 + 300);
2789        switch (p->status) {
2790        case DIFF_STATUS_COPIED:
2791                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2792                            line_prefix, set, similarity_index(p));
2793                strbuf_addf(msg, "%s\n%s%scopy from ",
2794                            reset,  line_prefix, set);
2795                quote_c_style(name, msg, NULL, 0);
2796                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2797                quote_c_style(other, msg, NULL, 0);
2798                strbuf_addf(msg, "%s\n", reset);
2799                break;
2800        case DIFF_STATUS_RENAMED:
2801                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2802                            line_prefix, set, similarity_index(p));
2803                strbuf_addf(msg, "%s\n%s%srename from ",
2804                            reset, line_prefix, set);
2805                quote_c_style(name, msg, NULL, 0);
2806                strbuf_addf(msg, "%s\n%s%srename to ",
2807                            reset, line_prefix, set);
2808                quote_c_style(other, msg, NULL, 0);
2809                strbuf_addf(msg, "%s\n", reset);
2810                break;
2811        case DIFF_STATUS_MODIFIED:
2812                if (p->score) {
2813                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2814                                    line_prefix,
2815                                    set, similarity_index(p), reset);
2816                        break;
2817                }
2818                /* fallthru */
2819        default:
2820                *must_show_header = 0;
2821        }
2822        if (one && two && hashcmp(one->sha1, two->sha1)) {
2823                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2824
2825                if (DIFF_OPT_TST(o, BINARY)) {
2826                        mmfile_t mf;
2827                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2828                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2829                                abbrev = 40;
2830                }
2831                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2832                            find_unique_abbrev(one->sha1, abbrev));
2833                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2834                if (one->mode == two->mode)
2835                        strbuf_addf(msg, " %06o", one->mode);
2836                strbuf_addf(msg, "%s\n", reset);
2837        }
2838}
2839
2840static void run_diff_cmd(const char *pgm,
2841                         const char *name,
2842                         const char *other,
2843                         const char *attr_path,
2844                         struct diff_filespec *one,
2845                         struct diff_filespec *two,
2846                         struct strbuf *msg,
2847                         struct diff_options *o,
2848                         struct diff_filepair *p)
2849{
2850        const char *xfrm_msg = NULL;
2851        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2852        int must_show_header = 0;
2853
2854        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2855                pgm = NULL;
2856        else {
2857                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2858                if (drv && drv->external)
2859                        pgm = drv->external;
2860        }
2861
2862        if (msg) {
2863                /*
2864                 * don't use colors when the header is intended for an
2865                 * external diff driver
2866                 */
2867                fill_metainfo(msg, name, other, one, two, o, p,
2868                              &must_show_header,
2869                              want_color(o->use_color) && !pgm);
2870                xfrm_msg = msg->len ? msg->buf : NULL;
2871        }
2872
2873        if (pgm) {
2874                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2875                                  complete_rewrite);
2876                return;
2877        }
2878        if (one && two)
2879                builtin_diff(name, other ? other : name,
2880                             one, two, xfrm_msg, must_show_header,
2881                             o, complete_rewrite);
2882        else
2883                fprintf(o->file, "* Unmerged path %s\n", name);
2884}
2885
2886static void diff_fill_sha1_info(struct diff_filespec *one)
2887{
2888        if (DIFF_FILE_VALID(one)) {
2889                if (!one->sha1_valid) {
2890                        struct stat st;
2891                        if (!strcmp(one->path, "-")) {
2892                                hashcpy(one->sha1, null_sha1);
2893                                return;
2894                        }
2895                        if (lstat(one->path, &st) < 0)
2896                                die_errno("stat '%s'", one->path);
2897                        if (index_path(one->sha1, one->path, &st, 0))
2898                                die("cannot hash %s", one->path);
2899                }
2900        }
2901        else
2902                hashclr(one->sha1);
2903}
2904
2905static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2906{
2907        /* Strip the prefix but do not molest /dev/null and absolute paths */
2908        if (*namep && **namep != '/') {
2909                *namep += prefix_length;
2910                if (**namep == '/')
2911                        ++*namep;
2912        }
2913        if (*otherp && **otherp != '/') {
2914                *otherp += prefix_length;
2915                if (**otherp == '/')
2916                        ++*otherp;
2917        }
2918}
2919
2920static void run_diff(struct diff_filepair *p, struct diff_options *o)
2921{
2922        const char *pgm = external_diff();
2923        struct strbuf msg;
2924        struct diff_filespec *one = p->one;
2925        struct diff_filespec *two = p->two;
2926        const char *name;
2927        const char *other;
2928        const char *attr_path;
2929
2930        name  = p->one->path;
2931        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2932        attr_path = name;
2933        if (o->prefix_length)
2934                strip_prefix(o->prefix_length, &name, &other);
2935
2936        if (DIFF_PAIR_UNMERGED(p)) {
2937                run_diff_cmd(pgm, name, NULL, attr_path,
2938                             NULL, NULL, NULL, o, p);
2939                return;
2940        }
2941
2942        diff_fill_sha1_info(one);
2943        diff_fill_sha1_info(two);
2944
2945        if (!pgm &&
2946            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2947            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2948                /*
2949                 * a filepair that changes between file and symlink
2950                 * needs to be split into deletion and creation.
2951                 */
2952                struct diff_filespec *null = alloc_filespec(two->path);
2953                run_diff_cmd(NULL, name, other, attr_path,
2954                             one, null, &msg, o, p);
2955                free(null);
2956                strbuf_release(&msg);
2957
2958                null = alloc_filespec(one->path);
2959                run_diff_cmd(NULL, name, other, attr_path,
2960                             null, two, &msg, o, p);
2961                free(null);
2962        }
2963        else
2964                run_diff_cmd(pgm, name, other, attr_path,
2965                             one, two, &msg, o, p);
2966
2967        strbuf_release(&msg);
2968}
2969
2970static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2971                         struct diffstat_t *diffstat)
2972{
2973        const char *name;
2974        const char *other;
2975        int complete_rewrite = 0;
2976
2977        if (DIFF_PAIR_UNMERGED(p)) {
2978                /* unmerged */
2979                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2980                return;
2981        }
2982
2983        name = p->one->path;
2984        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2985
2986        if (o->prefix_length)
2987                strip_prefix(o->prefix_length, &name, &other);
2988
2989        diff_fill_sha1_info(p->one);
2990        diff_fill_sha1_info(p->two);
2991
2992        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2993                complete_rewrite = 1;
2994        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2995}
2996
2997static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2998{
2999        const char *name;
3000        const char *other;
3001        const char *attr_path;
3002
3003        if (DIFF_PAIR_UNMERGED(p)) {
3004                /* unmerged */
3005                return;
3006        }
3007
3008        name = p->one->path;
3009        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3010        attr_path = other ? other : name;
3011
3012        if (o->prefix_length)
3013                strip_prefix(o->prefix_length, &name, &other);
3014
3015        diff_fill_sha1_info(p->one);
3016        diff_fill_sha1_info(p->two);
3017
3018        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3019}
3020
3021void diff_setup(struct diff_options *options)
3022{
3023        memcpy(options, &default_diff_options, sizeof(*options));
3024
3025        options->file = stdout;
3026
3027        options->line_termination = '\n';
3028        options->break_opt = -1;
3029        options->rename_limit = -1;
3030        options->dirstat_permille = diff_dirstat_permille_default;
3031        options->context = 3;
3032
3033        options->change = diff_change;
3034        options->add_remove = diff_addremove;
3035        options->use_color = diff_use_color_default;
3036        options->detect_rename = diff_detect_rename_default;
3037
3038        if (diff_no_prefix) {
3039                options->a_prefix = options->b_prefix = "";
3040        } else if (!diff_mnemonic_prefix) {
3041                options->a_prefix = "a/";
3042                options->b_prefix = "b/";
3043        }
3044}
3045
3046int diff_setup_done(struct diff_options *options)
3047{
3048        int count = 0;
3049
3050        if (options->output_format & DIFF_FORMAT_NAME)
3051                count++;
3052        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3053                count++;
3054        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3055                count++;
3056        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3057                count++;
3058        if (count > 1)
3059                die("--name-only, --name-status, --check and -s are mutually exclusive");
3060
3061        /*
3062         * Most of the time we can say "there are changes"
3063         * only by checking if there are changed paths, but
3064         * --ignore-whitespace* options force us to look
3065         * inside contents.
3066         */
3067
3068        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3069            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3070            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3071                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3072        else
3073                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3074
3075        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3076                options->detect_rename = DIFF_DETECT_COPY;
3077
3078        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3079                options->prefix = NULL;
3080        if (options->prefix)
3081                options->prefix_length = strlen(options->prefix);
3082        else
3083                options->prefix_length = 0;
3084
3085        if (options->output_format & (DIFF_FORMAT_NAME |
3086                                      DIFF_FORMAT_NAME_STATUS |
3087                                      DIFF_FORMAT_CHECKDIFF |
3088                                      DIFF_FORMAT_NO_OUTPUT))
3089                options->output_format &= ~(DIFF_FORMAT_RAW |
3090                                            DIFF_FORMAT_NUMSTAT |
3091                                            DIFF_FORMAT_DIFFSTAT |
3092                                            DIFF_FORMAT_SHORTSTAT |
3093                                            DIFF_FORMAT_DIRSTAT |
3094                                            DIFF_FORMAT_SUMMARY |
3095                                            DIFF_FORMAT_PATCH);
3096
3097        /*
3098         * These cases always need recursive; we do not drop caller-supplied
3099         * recursive bits for other formats here.
3100         */
3101        if (options->output_format & (DIFF_FORMAT_PATCH |
3102                                      DIFF_FORMAT_NUMSTAT |
3103                                      DIFF_FORMAT_DIFFSTAT |
3104                                      DIFF_FORMAT_SHORTSTAT |
3105                                      DIFF_FORMAT_DIRSTAT |
3106                                      DIFF_FORMAT_SUMMARY |
3107                                      DIFF_FORMAT_CHECKDIFF))
3108                DIFF_OPT_SET(options, RECURSIVE);
3109        /*
3110         * Also pickaxe would not work very well if you do not say recursive
3111         */
3112        if (options->pickaxe)
3113                DIFF_OPT_SET(options, RECURSIVE);
3114        /*
3115         * When patches are generated, submodules diffed against the work tree
3116         * must be checked for dirtiness too so it can be shown in the output
3117         */
3118        if (options->output_format & DIFF_FORMAT_PATCH)
3119                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3120
3121        if (options->detect_rename && options->rename_limit < 0)
3122                options->rename_limit = diff_rename_limit_default;
3123        if (options->setup & DIFF_SETUP_USE_CACHE) {
3124                if (!active_cache)
3125                        /* read-cache does not die even when it fails
3126                         * so it is safe for us to do this here.  Also
3127                         * it does not smudge active_cache or active_nr
3128                         * when it fails, so we do not have to worry about
3129                         * cleaning it up ourselves either.
3130                         */
3131                        read_cache();
3132        }
3133        if (options->abbrev <= 0 || 40 < options->abbrev)
3134                options->abbrev = 40; /* full */
3135
3136        /*
3137         * It does not make sense to show the first hit we happened
3138         * to have found.  It does not make sense not to return with
3139         * exit code in such a case either.
3140         */
3141        if (DIFF_OPT_TST(options, QUICK)) {
3142                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3143                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3144        }
3145
3146        return 0;
3147}
3148
3149static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3150{
3151        char c, *eq;
3152        int len;
3153
3154        if (*arg != '-')
3155                return 0;
3156        c = *++arg;
3157        if (!c)
3158                return 0;
3159        if (c == arg_short) {
3160                c = *++arg;
3161                if (!c)
3162                        return 1;
3163                if (val && isdigit(c)) {
3164                        char *end;
3165                        int n = strtoul(arg, &end, 10);
3166                        if (*end)
3167                                return 0;
3168                        *val = n;
3169                        return 1;
3170                }
3171                return 0;
3172        }
3173        if (c != '-')
3174                return 0;
3175        arg++;
3176        eq = strchr(arg, '=');
3177        if (eq)
3178                len = eq - arg;
3179        else
3180                len = strlen(arg);
3181        if (!len || strncmp(arg, arg_long, len))
3182                return 0;
3183        if (eq) {
3184                int n;
3185                char *end;
3186                if (!isdigit(*++eq))
3187                        return 0;
3188                n = strtoul(eq, &end, 10);
3189                if (*end)
3190                        return 0;
3191                *val = n;
3192        }
3193        return 1;
3194}
3195
3196static int diff_scoreopt_parse(const char *opt);
3197
3198static inline int short_opt(char opt, const char **argv,
3199                            const char **optarg)
3200{
3201        const char *arg = argv[0];
3202        if (arg[0] != '-' || arg[1] != opt)
3203                return 0;
3204        if (arg[2] != '\0') {
3205                *optarg = arg + 2;
3206                return 1;
3207        }
3208        if (!argv[1])
3209                die("Option '%c' requires a value", opt);
3210        *optarg = argv[1];
3211        return 2;
3212}
3213
3214int parse_long_opt(const char *opt, const char **argv,
3215                   const char **optarg)
3216{
3217        const char *arg = argv[0];
3218        if (arg[0] != '-' || arg[1] != '-')
3219                return 0;
3220        arg += strlen("--");
3221        if (prefixcmp(arg, opt))
3222                return 0;
3223        arg += strlen(opt);
3224        if (*arg == '=') { /* sticked form: --option=value */
3225                *optarg = arg + 1;
3226                return 1;
3227        }
3228        if (*arg != '\0')
3229                return 0;
3230        /* separate form: --option value */
3231        if (!argv[1])
3232                die("Option '--%s' requires a value", opt);
3233        *optarg = argv[1];
3234        return 2;
3235}
3236
3237static int stat_opt(struct diff_options *options, const char **av)
3238{
3239        const char *arg = av[0];
3240        char *end;
3241        int width = options->stat_width;
3242        int name_width = options->stat_name_width;
3243        int count = options->stat_count;
3244        int argcount = 1;
3245
3246        arg += strlen("--stat");
3247        end = (char *)arg;
3248
3249        switch (*arg) {
3250        case '-':
3251                if (!prefixcmp(arg, "-width")) {
3252                        arg += strlen("-width");
3253                        if (*arg == '=')
3254                                width = strtoul(arg + 1, &end, 10);
3255                        else if (!*arg && !av[1])
3256                                die("Option '--stat-width' requires a value");
3257                        else if (!*arg) {
3258                                width = strtoul(av[1], &end, 10);
3259                                argcount = 2;
3260                        }
3261                } else if (!prefixcmp(arg, "-name-width")) {
3262                        arg += strlen("-name-width");
3263                        if (*arg == '=')
3264                                name_width = strtoul(arg + 1, &end, 10);
3265                        else if (!*arg && !av[1])
3266                                die("Option '--stat-name-width' requires a value");
3267                        else if (!*arg) {
3268                                name_width = strtoul(av[1], &end, 10);
3269                                argcount = 2;
3270                        }
3271                } else if (!prefixcmp(arg, "-count")) {
3272                        arg += strlen("-count");
3273                        if (*arg == '=')
3274                                count = strtoul(arg + 1, &end, 10);
3275                        else if (!*arg && !av[1])
3276                                die("Option '--stat-count' requires a value");
3277                        else if (!*arg) {
3278                                count = strtoul(av[1], &end, 10);
3279                                argcount = 2;
3280                        }
3281                }
3282                break;
3283        case '=':
3284                width = strtoul(arg+1, &end, 10);
3285                if (*end == ',')
3286                        name_width = strtoul(end+1, &end, 10);
3287                if (*end == ',')
3288                        count = strtoul(end+1, &end, 10);
3289        }
3290
3291        /* Important! This checks all the error cases! */
3292        if (*end)
3293                return 0;
3294        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3295        options->stat_name_width = name_width;
3296        options->stat_width = width;
3297        options->stat_count = count;
3298        return argcount;
3299}
3300
3301static int parse_dirstat_opt(struct diff_options *options, const char *params)
3302{
3303        struct strbuf errmsg = STRBUF_INIT;
3304        if (parse_dirstat_params(options, params, &errmsg))
3305                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3306                    errmsg.buf);
3307        strbuf_release(&errmsg);
3308        /*
3309         * The caller knows a dirstat-related option is given from the command
3310         * line; allow it to say "return this_function();"
3311         */
3312        options->output_format |= DIFF_FORMAT_DIRSTAT;
3313        return 1;
3314}
3315
3316int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3317{
3318        const char *arg = av[0];
3319        const char *optarg;
3320        int argcount;
3321
3322        /* Output format options */
3323        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3324                options->output_format |= DIFF_FORMAT_PATCH;
3325        else if (opt_arg(arg, 'U', "unified", &options->context))
3326                options->output_format |= DIFF_FORMAT_PATCH;
3327        else if (!strcmp(arg, "--raw"))
3328                options->output_format |= DIFF_FORMAT_RAW;
3329        else if (!strcmp(arg, "--patch-with-raw"))
3330                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3331        else if (!strcmp(arg, "--numstat"))
3332                options->output_format |= DIFF_FORMAT_NUMSTAT;
3333        else if (!strcmp(arg, "--shortstat"))
3334                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3335        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3336                return parse_dirstat_opt(options, "");
3337        else if (!prefixcmp(arg, "-X"))
3338                return parse_dirstat_opt(options, arg + 2);
3339        else if (!prefixcmp(arg, "--dirstat="))
3340                return parse_dirstat_opt(options, arg + 10);
3341        else if (!strcmp(arg, "--cumulative"))
3342                return parse_dirstat_opt(options, "cumulative");
3343        else if (!strcmp(arg, "--dirstat-by-file"))
3344                return parse_dirstat_opt(options, "files");
3345        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3346                parse_dirstat_opt(options, "files");
3347                return parse_dirstat_opt(options, arg + 18);
3348        }
3349        else if (!strcmp(arg, "--check"))
3350                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3351        else if (!strcmp(arg, "--summary"))
3352                options->output_format |= DIFF_FORMAT_SUMMARY;
3353        else if (!strcmp(arg, "--patch-with-stat"))
3354                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3355        else if (!strcmp(arg, "--name-only"))
3356                options->output_format |= DIFF_FORMAT_NAME;
3357        else if (!strcmp(arg, "--name-status"))
3358                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3359        else if (!strcmp(arg, "-s"))
3360                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3361        else if (!prefixcmp(arg, "--stat"))
3362                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3363                return stat_opt(options, av);
3364
3365        /* renames options */
3366        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3367                 !strcmp(arg, "--break-rewrites")) {
3368                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3369                        return error("invalid argument to -B: %s", arg+2);
3370        }
3371        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3372                 !strcmp(arg, "--find-renames")) {
3373                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3374                        return error("invalid argument to -M: %s", arg+2);
3375                options->detect_rename = DIFF_DETECT_RENAME;
3376        }
3377        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3378                options->irreversible_delete = 1;
3379        }
3380        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3381                 !strcmp(arg, "--find-copies")) {
3382                if (options->detect_rename == DIFF_DETECT_COPY)
3383                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3384                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3385                        return error("invalid argument to -C: %s", arg+2);
3386                options->detect_rename = DIFF_DETECT_COPY;
3387        }
3388        else if (!strcmp(arg, "--no-renames"))
3389                options->detect_rename = 0;
3390        else if (!strcmp(arg, "--relative"))
3391                DIFF_OPT_SET(options, RELATIVE_NAME);
3392        else if (!prefixcmp(arg, "--relative=")) {
3393                DIFF_OPT_SET(options, RELATIVE_NAME);
3394                options->prefix = arg + 11;
3395        }
3396
3397        /* xdiff options */
3398        else if (!strcmp(arg, "--minimal"))
3399                DIFF_XDL_SET(options, NEED_MINIMAL);
3400        else if (!strcmp(arg, "--no-minimal"))
3401                DIFF_XDL_CLR(options, NEED_MINIMAL);
3402        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3403                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3404        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3405                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3406        else if (!strcmp(arg, "--ignore-space-at-eol"))
3407                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3408        else if (!strcmp(arg, "--patience"))
3409                DIFF_XDL_SET(options, PATIENCE_DIFF);
3410        else if (!strcmp(arg, "--histogram"))
3411                DIFF_XDL_SET(options, HISTOGRAM_DIFF);
3412
3413        /* flags options */
3414        else if (!strcmp(arg, "--binary")) {
3415                options->output_format |= DIFF_FORMAT_PATCH;
3416                DIFF_OPT_SET(options, BINARY);
3417        }
3418        else if (!strcmp(arg, "--full-index"))
3419                DIFF_OPT_SET(options, FULL_INDEX);
3420        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3421                DIFF_OPT_SET(options, TEXT);
3422        else if (!strcmp(arg, "-R"))
3423                DIFF_OPT_SET(options, REVERSE_DIFF);
3424        else if (!strcmp(arg, "--find-copies-harder"))
3425                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3426        else if (!strcmp(arg, "--follow"))
3427                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3428        else if (!strcmp(arg, "--color"))
3429                options->use_color = 1;
3430        else if (!prefixcmp(arg, "--color=")) {
3431                int value = git_config_colorbool(NULL, arg+8);
3432                if (value < 0)
3433                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3434                options->use_color = value;
3435        }
3436        else if (!strcmp(arg, "--no-color"))
3437                options->use_color = 0;
3438        else if (!strcmp(arg, "--color-words")) {
3439                options->use_color = 1;
3440                options->word_diff = DIFF_WORDS_COLOR;
3441        }
3442        else if (!prefixcmp(arg, "--color-words=")) {
3443                options->use_color = 1;
3444                options->word_diff = DIFF_WORDS_COLOR;
3445                options->word_regex = arg + 14;
3446        }
3447        else if (!strcmp(arg, "--word-diff")) {
3448                if (options->word_diff == DIFF_WORDS_NONE)
3449                        options->word_diff = DIFF_WORDS_PLAIN;
3450        }
3451        else if (!prefixcmp(arg, "--word-diff=")) {
3452                const char *type = arg + 12;
3453                if (!strcmp(type, "plain"))
3454                        options->word_diff = DIFF_WORDS_PLAIN;
3455                else if (!strcmp(type, "color")) {
3456                        options->use_color = 1;
3457                        options->word_diff = DIFF_WORDS_COLOR;
3458                }
3459                else if (!strcmp(type, "porcelain"))
3460                        options->word_diff = DIFF_WORDS_PORCELAIN;
3461                else if (!strcmp(type, "none"))
3462                        options->word_diff = DIFF_WORDS_NONE;
3463                else
3464                        die("bad --word-diff argument: %s", type);
3465        }
3466        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3467                if (options->word_diff == DIFF_WORDS_NONE)
3468                        options->word_diff = DIFF_WORDS_PLAIN;
3469                options->word_regex = optarg;
3470                return argcount;
3471        }
3472        else if (!strcmp(arg, "--exit-code"))
3473                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3474        else if (!strcmp(arg, "--quiet"))
3475                DIFF_OPT_SET(options, QUICK);
3476        else if (!strcmp(arg, "--ext-diff"))
3477                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3478        else if (!strcmp(arg, "--no-ext-diff"))
3479                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3480        else if (!strcmp(arg, "--textconv"))
3481                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3482        else if (!strcmp(arg, "--no-textconv"))
3483                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3484        else if (!strcmp(arg, "--ignore-submodules")) {
3485                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3486                handle_ignore_submodules_arg(options, "all");
3487        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3488                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3489                handle_ignore_submodules_arg(options, arg + 20);
3490        } else if (!strcmp(arg, "--submodule"))
3491                DIFF_OPT_SET(options, SUBMODULE_LOG);
3492        else if (!prefixcmp(arg, "--submodule=")) {
3493                if (!strcmp(arg + 12, "log"))
3494                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3495        }
3496
3497        /* misc options */
3498        else if (!strcmp(arg, "-z"))
3499                options->line_termination = 0;
3500        else if ((argcount = short_opt('l', av, &optarg))) {
3501                options->rename_limit = strtoul(optarg, NULL, 10);
3502                return argcount;
3503        }
3504        else if ((argcount = short_opt('S', av, &optarg))) {
3505                options->pickaxe = optarg;
3506                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3507                return argcount;
3508        } else if ((argcount = short_opt('G', av, &optarg))) {
3509                options->pickaxe = optarg;
3510                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3511                return argcount;
3512        }
3513        else if (!strcmp(arg, "--pickaxe-all"))
3514                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3515        else if (!strcmp(arg, "--pickaxe-regex"))
3516                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3517        else if ((argcount = short_opt('O', av, &optarg))) {
3518                options->orderfile = optarg;
3519                return argcount;
3520        }
3521        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3522                options->filter = optarg;
3523                return argcount;
3524        }
3525        else if (!strcmp(arg, "--abbrev"))
3526                options->abbrev = DEFAULT_ABBREV;
3527        else if (!prefixcmp(arg, "--abbrev=")) {
3528                options->abbrev = strtoul(arg + 9, NULL, 10);
3529                if (options->abbrev < MINIMUM_ABBREV)
3530                        options->abbrev = MINIMUM_ABBREV;
3531                else if (40 < options->abbrev)
3532                        options->abbrev = 40;
3533        }
3534        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3535                options->a_prefix = optarg;
3536                return argcount;
3537        }
3538        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3539                options->b_prefix = optarg;
3540                return argcount;
3541        }
3542        else if (!strcmp(arg, "--no-prefix"))
3543                options->a_prefix = options->b_prefix = "";
3544        else if (opt_arg(arg, '\0', "inter-hunk-context",
3545                         &options->interhunkcontext))
3546                ;
3547        else if (!strcmp(arg, "-W"))
3548                DIFF_OPT_SET(options, FUNCCONTEXT);
3549        else if (!strcmp(arg, "--function-context"))
3550                DIFF_OPT_SET(options, FUNCCONTEXT);
3551        else if (!strcmp(arg, "--no-function-context"))
3552                DIFF_OPT_CLR(options, FUNCCONTEXT);
3553        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3554                options->file = fopen(optarg, "w");
3555                if (!options->file)
3556                        die_errno("Could not open '%s'", optarg);
3557                options->close_file = 1;
3558                return argcount;
3559        } else
3560                return 0;
3561        return 1;
3562}
3563
3564int parse_rename_score(const char **cp_p)
3565{
3566        unsigned long num, scale;
3567        int ch, dot;
3568        const char *cp = *cp_p;
3569
3570        num = 0;
3571        scale = 1;
3572        dot = 0;
3573        for (;;) {
3574                ch = *cp;
3575                if ( !dot && ch == '.' ) {
3576                        scale = 1;
3577                        dot = 1;
3578                } else if ( ch == '%' ) {
3579                        scale = dot ? scale*100 : 100;
3580                        cp++;   /* % is always at the end */
3581                        break;
3582                } else if ( ch >= '0' && ch <= '9' ) {
3583                        if ( scale < 100000 ) {
3584                                scale *= 10;
3585                                num = (num*10) + (ch-'0');
3586                        }
3587                } else {
3588                        break;
3589                }
3590                cp++;
3591        }
3592        *cp_p = cp;
3593
3594        /* user says num divided by scale and we say internally that
3595         * is MAX_SCORE * num / scale.
3596         */
3597        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3598}
3599
3600static int diff_scoreopt_parse(const char *opt)
3601{
3602        int opt1, opt2, cmd;
3603
3604        if (*opt++ != '-')
3605                return -1;
3606        cmd = *opt++;
3607        if (cmd == '-') {
3608                /* convert the long-form arguments into short-form versions */
3609                if (!prefixcmp(opt, "break-rewrites")) {
3610                        opt += strlen("break-rewrites");
3611                        if (*opt == 0 || *opt++ == '=')
3612                                cmd = 'B';
3613                } else if (!prefixcmp(opt, "find-copies")) {
3614                        opt += strlen("find-copies");
3615                        if (*opt == 0 || *opt++ == '=')
3616                                cmd = 'C';
3617                } else if (!prefixcmp(opt, "find-renames")) {
3618                        opt += strlen("find-renames");
3619                        if (*opt == 0 || *opt++ == '=')
3620                                cmd = 'M';
3621                }
3622        }
3623        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3624                return -1; /* that is not a -M, -C nor -B option */
3625
3626        opt1 = parse_rename_score(&opt);
3627        if (cmd != 'B')
3628                opt2 = 0;
3629        else {
3630                if (*opt == 0)
3631                        opt2 = 0;
3632                else if (*opt != '/')
3633                        return -1; /* we expect -B80/99 or -B80 */
3634                else {
3635                        opt++;
3636                        opt2 = parse_rename_score(&opt);
3637                }
3638        }
3639        if (*opt != 0)
3640                return -1;
3641        return opt1 | (opt2 << 16);
3642}
3643
3644struct diff_queue_struct diff_queued_diff;
3645
3646void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3647{
3648        if (queue->alloc <= queue->nr) {
3649                queue->alloc = alloc_nr(queue->alloc);
3650                queue->queue = xrealloc(queue->queue,
3651                                        sizeof(dp) * queue->alloc);
3652        }
3653        queue->queue[queue->nr++] = dp;
3654}
3655
3656struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3657                                 struct diff_filespec *one,
3658                                 struct diff_filespec *two)
3659{
3660        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3661        dp->one = one;
3662        dp->two = two;
3663        if (queue)
3664                diff_q(queue, dp);
3665        return dp;
3666}
3667
3668void diff_free_filepair(struct diff_filepair *p)
3669{
3670        free_filespec(p->one);
3671        free_filespec(p->two);
3672        free(p);
3673}
3674
3675/* This is different from find_unique_abbrev() in that
3676 * it stuffs the result with dots for alignment.
3677 */
3678const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3679{
3680        int abblen;
3681        const char *abbrev;
3682        if (len == 40)
3683                return sha1_to_hex(sha1);
3684
3685        abbrev = find_unique_abbrev(sha1, len);
3686        abblen = strlen(abbrev);
3687        if (abblen < 37) {
3688                static char hex[41];
3689                if (len < abblen && abblen <= len + 2)
3690                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3691                else
3692                        sprintf(hex, "%s...", abbrev);
3693                return hex;
3694        }
3695        return sha1_to_hex(sha1);
3696}
3697
3698static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3699{
3700        int line_termination = opt->line_termination;
3701        int inter_name_termination = line_termination ? '\t' : '\0';
3702        if (opt->output_prefix) {
3703                struct strbuf *msg = NULL;
3704                msg = opt->output_prefix(opt, opt->output_prefix_data);
3705                fprintf(opt->file, "%s", msg->buf);
3706        }
3707
3708        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3709                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3710                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3711                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3712        }
3713        if (p->score) {
3714                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3715                        inter_name_termination);
3716        } else {
3717                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3718        }
3719
3720        if (p->status == DIFF_STATUS_COPIED ||
3721            p->status == DIFF_STATUS_RENAMED) {
3722                const char *name_a, *name_b;
3723                name_a = p->one->path;
3724                name_b = p->two->path;
3725                strip_prefix(opt->prefix_length, &name_a, &name_b);
3726                write_name_quoted(name_a, opt->file, inter_name_termination);
3727                write_name_quoted(name_b, opt->file, line_termination);
3728        } else {
3729                const char *name_a, *name_b;
3730                name_a = p->one->mode ? p->one->path : p->two->path;
3731                name_b = NULL;
3732                strip_prefix(opt->prefix_length, &name_a, &name_b);
3733                write_name_quoted(name_a, opt->file, line_termination);
3734        }
3735}
3736
3737int diff_unmodified_pair(struct diff_filepair *p)
3738{
3739        /* This function is written stricter than necessary to support
3740         * the currently implemented transformers, but the idea is to
3741         * let transformers to produce diff_filepairs any way they want,
3742         * and filter and clean them up here before producing the output.
3743         */
3744        struct diff_filespec *one = p->one, *two = p->two;
3745
3746        if (DIFF_PAIR_UNMERGED(p))
3747                return 0; /* unmerged is interesting */
3748
3749        /* deletion, addition, mode or type change
3750         * and rename are all interesting.
3751         */
3752        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3753            DIFF_PAIR_MODE_CHANGED(p) ||
3754            strcmp(one->path, two->path))
3755                return 0;
3756
3757        /* both are valid and point at the same path.  that is, we are
3758         * dealing with a change.
3759         */
3760        if (one->sha1_valid && two->sha1_valid &&
3761            !hashcmp(one->sha1, two->sha1) &&
3762            !one->dirty_submodule && !two->dirty_submodule)
3763                return 1; /* no change */
3764        if (!one->sha1_valid && !two->sha1_valid)
3765                return 1; /* both look at the same file on the filesystem. */
3766        return 0;
3767}
3768
3769static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3770{
3771        if (diff_unmodified_pair(p))
3772                return;
3773
3774        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3775            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3776                return; /* no tree diffs in patch format */
3777
3778        run_diff(p, o);
3779}
3780
3781static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3782                            struct diffstat_t *diffstat)
3783{
3784        if (diff_unmodified_pair(p))
3785                return;
3786
3787        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3788            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3789                return; /* no useful stat for tree diffs */
3790
3791        run_diffstat(p, o, diffstat);
3792}
3793
3794static void diff_flush_checkdiff(struct diff_filepair *p,
3795                struct diff_options *o)
3796{
3797        if (diff_unmodified_pair(p))
3798                return;
3799
3800        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3801            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3802                return; /* nothing to check in tree diffs */
3803
3804        run_checkdiff(p, o);
3805}
3806
3807int diff_queue_is_empty(void)
3808{
3809        struct diff_queue_struct *q = &diff_queued_diff;
3810        int i;
3811        for (i = 0; i < q->nr; i++)
3812                if (!diff_unmodified_pair(q->queue[i]))
3813                        return 0;
3814        return 1;
3815}
3816
3817#if DIFF_DEBUG
3818void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3819{
3820        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3821                x, one ? one : "",
3822                s->path,
3823                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3824                s->mode,
3825                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3826        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3827                x, one ? one : "",
3828                s->size, s->xfrm_flags);
3829}
3830
3831void diff_debug_filepair(const struct diff_filepair *p, int i)
3832{
3833        diff_debug_filespec(p->one, i, "one");
3834        diff_debug_filespec(p->two, i, "two");
3835        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3836                p->score, p->status ? p->status : '?',
3837                p->one->rename_used, p->broken_pair);
3838}
3839
3840void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3841{
3842        int i;
3843        if (msg)
3844                fprintf(stderr, "%s\n", msg);
3845        fprintf(stderr, "q->nr = %d\n", q->nr);
3846        for (i = 0; i < q->nr; i++) {
3847                struct diff_filepair *p = q->queue[i];
3848                diff_debug_filepair(p, i);
3849        }
3850}
3851#endif
3852
3853static void diff_resolve_rename_copy(void)
3854{
3855        int i;
3856        struct diff_filepair *p;
3857        struct diff_queue_struct *q = &diff_queued_diff;
3858
3859        diff_debug_queue("resolve-rename-copy", q);
3860
3861        for (i = 0; i < q->nr; i++) {
3862                p = q->queue[i];
3863                p->status = 0; /* undecided */
3864                if (DIFF_PAIR_UNMERGED(p))
3865                        p->status = DIFF_STATUS_UNMERGED;
3866                else if (!DIFF_FILE_VALID(p->one))
3867                        p->status = DIFF_STATUS_ADDED;
3868                else if (!DIFF_FILE_VALID(p->two))
3869                        p->status = DIFF_STATUS_DELETED;
3870                else if (DIFF_PAIR_TYPE_CHANGED(p))
3871                        p->status = DIFF_STATUS_TYPE_CHANGED;
3872
3873                /* from this point on, we are dealing with a pair
3874                 * whose both sides are valid and of the same type, i.e.
3875                 * either in-place edit or rename/copy edit.
3876                 */
3877                else if (DIFF_PAIR_RENAME(p)) {
3878                        /*
3879                         * A rename might have re-connected a broken
3880                         * pair up, causing the pathnames to be the
3881                         * same again. If so, that's not a rename at
3882                         * all, just a modification..
3883                         *
3884                         * Otherwise, see if this source was used for
3885                         * multiple renames, in which case we decrement
3886                         * the count, and call it a copy.
3887                         */
3888                        if (!strcmp(p->one->path, p->two->path))
3889                                p->status = DIFF_STATUS_MODIFIED;
3890                        else if (--p->one->rename_used > 0)
3891                                p->status = DIFF_STATUS_COPIED;
3892                        else
3893                                p->status = DIFF_STATUS_RENAMED;
3894                }
3895                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3896                         p->one->mode != p->two->mode ||
3897                         p->one->dirty_submodule ||
3898                         p->two->dirty_submodule ||
3899                         is_null_sha1(p->one->sha1))
3900                        p->status = DIFF_STATUS_MODIFIED;
3901                else {
3902                        /* This is a "no-change" entry and should not
3903                         * happen anymore, but prepare for broken callers.
3904                         */
3905                        error("feeding unmodified %s to diffcore",
3906                              p->one->path);
3907                        p->status = DIFF_STATUS_UNKNOWN;
3908                }
3909        }
3910        diff_debug_queue("resolve-rename-copy done", q);
3911}
3912
3913static int check_pair_status(struct diff_filepair *p)
3914{
3915        switch (p->status) {
3916        case DIFF_STATUS_UNKNOWN:
3917                return 0;
3918        case 0:
3919                die("internal error in diff-resolve-rename-copy");
3920        default:
3921                return 1;
3922        }
3923}
3924
3925static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3926{
3927        int fmt = opt->output_format;
3928
3929        if (fmt & DIFF_FORMAT_CHECKDIFF)
3930                diff_flush_checkdiff(p, opt);
3931        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3932                diff_flush_raw(p, opt);
3933        else if (fmt & DIFF_FORMAT_NAME) {
3934                const char *name_a, *name_b;
3935                name_a = p->two->path;
3936                name_b = NULL;
3937                strip_prefix(opt->prefix_length, &name_a, &name_b);
3938                write_name_quoted(name_a, opt->file, opt->line_termination);
3939        }
3940}
3941
3942static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3943{
3944        if (fs->mode)
3945                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3946        else
3947                fprintf(file, " %s ", newdelete);
3948        write_name_quoted(fs->path, file, '\n');
3949}
3950
3951
3952static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3953                const char *line_prefix)
3954{
3955        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3956                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3957                        p->two->mode, show_name ? ' ' : '\n');
3958                if (show_name) {
3959                        write_name_quoted(p->two->path, file, '\n');
3960                }
3961        }
3962}
3963
3964static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3965                        const char *line_prefix)
3966{
3967        char *names = pprint_rename(p->one->path, p->two->path);
3968
3969        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3970        free(names);
3971        show_mode_change(file, p, 0, line_prefix);
3972}
3973
3974static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3975{
3976        FILE *file = opt->file;
3977        char *line_prefix = "";
3978
3979        if (opt->output_prefix) {
3980                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3981                line_prefix = buf->buf;
3982        }
3983
3984        switch(p->status) {
3985        case DIFF_STATUS_DELETED:
3986                fputs(line_prefix, file);
3987                show_file_mode_name(file, "delete", p->one);
3988                break;
3989        case DIFF_STATUS_ADDED:
3990                fputs(line_prefix, file);
3991                show_file_mode_name(file, "create", p->two);
3992                break;
3993        case DIFF_STATUS_COPIED:
3994                fputs(line_prefix, file);
3995                show_rename_copy(file, "copy", p, line_prefix);
3996                break;
3997        case DIFF_STATUS_RENAMED:
3998                fputs(line_prefix, file);
3999                show_rename_copy(file, "rename", p, line_prefix);
4000                break;
4001        default:
4002                if (p->score) {
4003                        fprintf(file, "%s rewrite ", line_prefix);
4004                        write_name_quoted(p->two->path, file, ' ');
4005                        fprintf(file, "(%d%%)\n", similarity_index(p));
4006                }
4007                show_mode_change(file, p, !p->score, line_prefix);
4008                break;
4009        }
4010}
4011
4012struct patch_id_t {
4013        git_SHA_CTX *ctx;
4014        int patchlen;
4015};
4016
4017static int remove_space(char *line, int len)
4018{
4019        int i;
4020        char *dst = line;
4021        unsigned char c;
4022
4023        for (i = 0; i < len; i++)
4024                if (!isspace((c = line[i])))
4025                        *dst++ = c;
4026
4027        return dst - line;
4028}
4029
4030static void patch_id_consume(void *priv, char *line, unsigned long len)
4031{
4032        struct patch_id_t *data = priv;
4033        int new_len;
4034
4035        /* Ignore line numbers when computing the SHA1 of the patch */
4036        if (!prefixcmp(line, "@@ -"))
4037                return;
4038
4039        new_len = remove_space(line, len);
4040
4041        git_SHA1_Update(data->ctx, line, new_len);
4042        data->patchlen += new_len;
4043}
4044
4045/* returns 0 upon success, and writes result into sha1 */
4046static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4047{
4048        struct diff_queue_struct *q = &diff_queued_diff;
4049        int i;
4050        git_SHA_CTX ctx;
4051        struct patch_id_t data;
4052        char buffer[PATH_MAX * 4 + 20];
4053
4054        git_SHA1_Init(&ctx);
4055        memset(&data, 0, sizeof(struct patch_id_t));
4056        data.ctx = &ctx;
4057
4058        for (i = 0; i < q->nr; i++) {
4059                xpparam_t xpp;
4060                xdemitconf_t xecfg;
4061                mmfile_t mf1, mf2;
4062                struct diff_filepair *p = q->queue[i];
4063                int len1, len2;
4064
4065                memset(&xpp, 0, sizeof(xpp));
4066                memset(&xecfg, 0, sizeof(xecfg));
4067                if (p->status == 0)
4068                        return error("internal diff status error");
4069                if (p->status == DIFF_STATUS_UNKNOWN)
4070                        continue;
4071                if (diff_unmodified_pair(p))
4072                        continue;
4073                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4074                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4075                        continue;
4076                if (DIFF_PAIR_UNMERGED(p))
4077                        continue;
4078
4079                diff_fill_sha1_info(p->one);
4080                diff_fill_sha1_info(p->two);
4081                if (fill_mmfile(&mf1, p->one) < 0 ||
4082                                fill_mmfile(&mf2, p->two) < 0)
4083                        return error("unable to read files to diff");
4084
4085                len1 = remove_space(p->one->path, strlen(p->one->path));
4086                len2 = remove_space(p->two->path, strlen(p->two->path));
4087                if (p->one->mode == 0)
4088                        len1 = snprintf(buffer, sizeof(buffer),
4089                                        "diff--gita/%.*sb/%.*s"
4090                                        "newfilemode%06o"
4091                                        "---/dev/null"
4092                                        "+++b/%.*s",
4093                                        len1, p->one->path,
4094                                        len2, p->two->path,
4095                                        p->two->mode,
4096                                        len2, p->two->path);
4097                else if (p->two->mode == 0)
4098                        len1 = snprintf(buffer, sizeof(buffer),
4099                                        "diff--gita/%.*sb/%.*s"
4100                                        "deletedfilemode%06o"
4101                                        "---a/%.*s"
4102                                        "+++/dev/null",
4103                                        len1, p->one->path,
4104                                        len2, p->two->path,
4105                                        p->one->mode,
4106                                        len1, p->one->path);
4107                else
4108                        len1 = snprintf(buffer, sizeof(buffer),
4109                                        "diff--gita/%.*sb/%.*s"
4110                                        "---a/%.*s"
4111                                        "+++b/%.*s",
4112                                        len1, p->one->path,
4113                                        len2, p->two->path,
4114                                        len1, p->one->path,
4115                                        len2, p->two->path);
4116                git_SHA1_Update(&ctx, buffer, len1);
4117
4118                if (diff_filespec_is_binary(p->one) ||
4119                    diff_filespec_is_binary(p->two)) {
4120                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4121                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4122                        continue;
4123                }
4124
4125                xpp.flags = 0;
4126                xecfg.ctxlen = 3;
4127                xecfg.flags = 0;
4128                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4129                              &xpp, &xecfg);
4130        }
4131
4132        git_SHA1_Final(sha1, &ctx);
4133        return 0;
4134}
4135
4136int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4137{
4138        struct diff_queue_struct *q = &diff_queued_diff;
4139        int i;
4140        int result = diff_get_patch_id(options, sha1);
4141
4142        for (i = 0; i < q->nr; i++)
4143                diff_free_filepair(q->queue[i]);
4144
4145        free(q->queue);
4146        DIFF_QUEUE_CLEAR(q);
4147
4148        return result;
4149}
4150
4151static int is_summary_empty(const struct diff_queue_struct *q)
4152{
4153        int i;
4154
4155        for (i = 0; i < q->nr; i++) {
4156                const struct diff_filepair *p = q->queue[i];
4157
4158                switch (p->status) {
4159                case DIFF_STATUS_DELETED:
4160                case DIFF_STATUS_ADDED:
4161                case DIFF_STATUS_COPIED:
4162                case DIFF_STATUS_RENAMED:
4163                        return 0;
4164                default:
4165                        if (p->score)
4166                                return 0;
4167                        if (p->one->mode && p->two->mode &&
4168                            p->one->mode != p->two->mode)
4169                                return 0;
4170                        break;
4171                }
4172        }
4173        return 1;
4174}
4175
4176static const char rename_limit_warning[] =
4177"inexact rename detection was skipped due to too many files.";
4178
4179static const char degrade_cc_to_c_warning[] =
4180"only found copies from modified paths due to too many files.";
4181
4182static const char rename_limit_advice[] =
4183"you may want to set your %s variable to at least "
4184"%d and retry the command.";
4185
4186void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4187{
4188        if (degraded_cc)
4189                warning(degrade_cc_to_c_warning);
4190        else if (needed)
4191                warning(rename_limit_warning);
4192        else
4193                return;
4194        if (0 < needed && needed < 32767)
4195                warning(rename_limit_advice, varname, needed);
4196}
4197
4198void diff_flush(struct diff_options *options)
4199{
4200        struct diff_queue_struct *q = &diff_queued_diff;
4201        int i, output_format = options->output_format;
4202        int separator = 0;
4203        int dirstat_by_line = 0;
4204
4205        /*
4206         * Order: raw, stat, summary, patch
4207         * or:    name/name-status/checkdiff (other bits clear)
4208         */
4209        if (!q->nr)
4210                goto free_queue;
4211
4212        if (output_format & (DIFF_FORMAT_RAW |
4213                             DIFF_FORMAT_NAME |
4214                             DIFF_FORMAT_NAME_STATUS |
4215                             DIFF_FORMAT_CHECKDIFF)) {
4216                for (i = 0; i < q->nr; i++) {
4217                        struct diff_filepair *p = q->queue[i];
4218                        if (check_pair_status(p))
4219                                flush_one_pair(p, options);
4220                }
4221                separator++;
4222        }
4223
4224        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4225                dirstat_by_line = 1;
4226
4227        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4228            dirstat_by_line) {
4229                struct diffstat_t diffstat;
4230
4231                memset(&diffstat, 0, sizeof(struct diffstat_t));
4232                for (i = 0; i < q->nr; i++) {
4233                        struct diff_filepair *p = q->queue[i];
4234                        if (check_pair_status(p))
4235                                diff_flush_stat(p, options, &diffstat);
4236                }
4237                if (output_format & DIFF_FORMAT_NUMSTAT)
4238                        show_numstat(&diffstat, options);
4239                if (output_format & DIFF_FORMAT_DIFFSTAT)
4240                        show_stats(&diffstat, options);
4241                if (output_format & DIFF_FORMAT_SHORTSTAT)
4242                        show_shortstats(&diffstat, options);
4243                if (output_format & DIFF_FORMAT_DIRSTAT)
4244                        show_dirstat_by_line(&diffstat, options);
4245                free_diffstat_info(&diffstat);
4246                separator++;
4247        }
4248        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4249                show_dirstat(options);
4250
4251        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4252                for (i = 0; i < q->nr; i++) {
4253                        diff_summary(options, q->queue[i]);
4254                }
4255                separator++;
4256        }
4257
4258        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4259            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4260            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4261                /*
4262                 * run diff_flush_patch for the exit status. setting
4263                 * options->file to /dev/null should be safe, becaue we
4264                 * aren't supposed to produce any output anyway.
4265                 */
4266                if (options->close_file)
4267                        fclose(options->file);
4268                options->file = fopen("/dev/null", "w");
4269                if (!options->file)
4270                        die_errno("Could not open /dev/null");
4271                options->close_file = 1;
4272                for (i = 0; i < q->nr; i++) {
4273                        struct diff_filepair *p = q->queue[i];
4274                        if (check_pair_status(p))
4275                                diff_flush_patch(p, options);
4276                        if (options->found_changes)
4277                                break;
4278                }
4279        }
4280
4281        if (output_format & DIFF_FORMAT_PATCH) {
4282                if (separator) {
4283                        putc(options->line_termination, options->file);
4284                        if (options->stat_sep) {
4285                                /* attach patch instead of inline */
4286                                fputs(options->stat_sep, options->file);
4287                        }
4288                }
4289
4290                for (i = 0; i < q->nr; i++) {
4291                        struct diff_filepair *p = q->queue[i];
4292                        if (check_pair_status(p))
4293                                diff_flush_patch(p, options);
4294                }
4295        }
4296
4297        if (output_format & DIFF_FORMAT_CALLBACK)
4298                options->format_callback(q, options, options->format_callback_data);
4299
4300        for (i = 0; i < q->nr; i++)
4301                diff_free_filepair(q->queue[i]);
4302free_queue:
4303        free(q->queue);
4304        DIFF_QUEUE_CLEAR(q);
4305        if (options->close_file)
4306                fclose(options->file);
4307
4308        /*
4309         * Report the content-level differences with HAS_CHANGES;
4310         * diff_addremove/diff_change does not set the bit when
4311         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4312         */
4313        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4314                if (options->found_changes)
4315                        DIFF_OPT_SET(options, HAS_CHANGES);
4316                else
4317                        DIFF_OPT_CLR(options, HAS_CHANGES);
4318        }
4319}
4320
4321static void diffcore_apply_filter(const char *filter)
4322{
4323        int i;
4324        struct diff_queue_struct *q = &diff_queued_diff;
4325        struct diff_queue_struct outq;
4326        DIFF_QUEUE_CLEAR(&outq);
4327
4328        if (!filter)
4329                return;
4330
4331        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4332                int found;
4333                for (i = found = 0; !found && i < q->nr; i++) {
4334                        struct diff_filepair *p = q->queue[i];
4335                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4336                             ((p->score &&
4337                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4338                              (!p->score &&
4339                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4340                            ((p->status != DIFF_STATUS_MODIFIED) &&
4341                             strchr(filter, p->status)))
4342                                found++;
4343                }
4344                if (found)
4345                        return;
4346
4347                /* otherwise we will clear the whole queue
4348                 * by copying the empty outq at the end of this
4349                 * function, but first clear the current entries
4350                 * in the queue.
4351                 */
4352                for (i = 0; i < q->nr; i++)
4353                        diff_free_filepair(q->queue[i]);
4354        }
4355        else {
4356                /* Only the matching ones */
4357                for (i = 0; i < q->nr; i++) {
4358                        struct diff_filepair *p = q->queue[i];
4359
4360                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4361                             ((p->score &&
4362                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4363                              (!p->score &&
4364                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4365                            ((p->status != DIFF_STATUS_MODIFIED) &&
4366                             strchr(filter, p->status)))
4367                                diff_q(&outq, p);
4368                        else
4369                                diff_free_filepair(p);
4370                }
4371        }
4372        free(q->queue);
4373        *q = outq;
4374}
4375
4376/* Check whether two filespecs with the same mode and size are identical */
4377static int diff_filespec_is_identical(struct diff_filespec *one,
4378                                      struct diff_filespec *two)
4379{
4380        if (S_ISGITLINK(one->mode))
4381                return 0;
4382        if (diff_populate_filespec(one, 0))
4383                return 0;
4384        if (diff_populate_filespec(two, 0))
4385                return 0;
4386        return !memcmp(one->data, two->data, one->size);
4387}
4388
4389static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4390{
4391        int i;
4392        struct diff_queue_struct *q = &diff_queued_diff;
4393        struct diff_queue_struct outq;
4394        DIFF_QUEUE_CLEAR(&outq);
4395
4396        for (i = 0; i < q->nr; i++) {
4397                struct diff_filepair *p = q->queue[i];
4398
4399                /*
4400                 * 1. Entries that come from stat info dirtiness
4401                 *    always have both sides (iow, not create/delete),
4402                 *    one side of the object name is unknown, with
4403                 *    the same mode and size.  Keep the ones that
4404                 *    do not match these criteria.  They have real
4405                 *    differences.
4406                 *
4407                 * 2. At this point, the file is known to be modified,
4408                 *    with the same mode and size, and the object
4409                 *    name of one side is unknown.  Need to inspect
4410                 *    the identical contents.
4411                 */
4412                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4413                    !DIFF_FILE_VALID(p->two) ||
4414                    (p->one->sha1_valid && p->two->sha1_valid) ||
4415                    (p->one->mode != p->two->mode) ||
4416                    diff_populate_filespec(p->one, 1) ||
4417                    diff_populate_filespec(p->two, 1) ||
4418                    (p->one->size != p->two->size) ||
4419                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4420                        diff_q(&outq, p);
4421                else {
4422                        /*
4423                         * The caller can subtract 1 from skip_stat_unmatch
4424                         * to determine how many paths were dirty only
4425                         * due to stat info mismatch.
4426                         */
4427                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4428                                diffopt->skip_stat_unmatch++;
4429                        diff_free_filepair(p);
4430                }
4431        }
4432        free(q->queue);
4433        *q = outq;
4434}
4435
4436static int diffnamecmp(const void *a_, const void *b_)
4437{
4438        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4439        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4440        const char *name_a, *name_b;
4441
4442        name_a = a->one ? a->one->path : a->two->path;
4443        name_b = b->one ? b->one->path : b->two->path;
4444        return strcmp(name_a, name_b);
4445}
4446
4447void diffcore_fix_diff_index(struct diff_options *options)
4448{
4449        struct diff_queue_struct *q = &diff_queued_diff;
4450        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4451}
4452
4453void diffcore_std(struct diff_options *options)
4454{
4455        if (options->skip_stat_unmatch)
4456                diffcore_skip_stat_unmatch(options);
4457        if (!options->found_follow) {
4458                /* See try_to_follow_renames() in tree-diff.c */
4459                if (options->break_opt != -1)
4460                        diffcore_break(options->break_opt);
4461                if (options->detect_rename)
4462                        diffcore_rename(options);
4463                if (options->break_opt != -1)
4464                        diffcore_merge_broken();
4465        }
4466        if (options->pickaxe)
4467                diffcore_pickaxe(options);
4468        if (options->orderfile)
4469                diffcore_order(options->orderfile);
4470        if (!options->found_follow)
4471                /* See try_to_follow_renames() in tree-diff.c */
4472                diff_resolve_rename_copy();
4473        diffcore_apply_filter(options->filter);
4474
4475        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4476                DIFF_OPT_SET(options, HAS_CHANGES);
4477        else
4478                DIFF_OPT_CLR(options, HAS_CHANGES);
4479
4480        options->found_follow = 0;
4481}
4482
4483int diff_result_code(struct diff_options *opt, int status)
4484{
4485        int result = 0;
4486
4487        diff_warn_rename_limit("diff.renamelimit",
4488                               opt->needed_rename_limit,
4489                               opt->degraded_cc_to_c);
4490        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4491            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4492                return status;
4493        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4494            DIFF_OPT_TST(opt, HAS_CHANGES))
4495                result |= 01;
4496        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4497            DIFF_OPT_TST(opt, CHECK_FAILED))
4498                result |= 02;
4499        return result;
4500}
4501
4502int diff_can_quit_early(struct diff_options *opt)
4503{
4504        return (DIFF_OPT_TST(opt, QUICK) &&
4505                !opt->filter &&
4506                DIFF_OPT_TST(opt, HAS_CHANGES));
4507}
4508
4509/*
4510 * Shall changes to this submodule be ignored?
4511 *
4512 * Submodule changes can be configured to be ignored separately for each path,
4513 * but that configuration can be overridden from the command line.
4514 */
4515static int is_submodule_ignored(const char *path, struct diff_options *options)
4516{
4517        int ignored = 0;
4518        unsigned orig_flags = options->flags;
4519        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4520                set_diffopt_flags_from_submodule_config(options, path);
4521        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4522                ignored = 1;
4523        options->flags = orig_flags;
4524        return ignored;
4525}
4526
4527void diff_addremove(struct diff_options *options,
4528                    int addremove, unsigned mode,
4529                    const unsigned char *sha1,
4530                    const char *concatpath, unsigned dirty_submodule)
4531{
4532        struct diff_filespec *one, *two;
4533
4534        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4535                return;
4536
4537        /* This may look odd, but it is a preparation for
4538         * feeding "there are unchanged files which should
4539         * not produce diffs, but when you are doing copy
4540         * detection you would need them, so here they are"
4541         * entries to the diff-core.  They will be prefixed
4542         * with something like '=' or '*' (I haven't decided
4543         * which but should not make any difference).
4544         * Feeding the same new and old to diff_change()
4545         * also has the same effect.
4546         * Before the final output happens, they are pruned after
4547         * merged into rename/copy pairs as appropriate.
4548         */
4549        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4550                addremove = (addremove == '+' ? '-' :
4551                             addremove == '-' ? '+' : addremove);
4552
4553        if (options->prefix &&
4554            strncmp(concatpath, options->prefix, options->prefix_length))
4555                return;
4556
4557        one = alloc_filespec(concatpath);
4558        two = alloc_filespec(concatpath);
4559
4560        if (addremove != '+')
4561                fill_filespec(one, sha1, mode);
4562        if (addremove != '-') {
4563                fill_filespec(two, sha1, mode);
4564                two->dirty_submodule = dirty_submodule;
4565        }
4566
4567        diff_queue(&diff_queued_diff, one, two);
4568        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4569                DIFF_OPT_SET(options, HAS_CHANGES);
4570}
4571
4572void diff_change(struct diff_options *options,
4573                 unsigned old_mode, unsigned new_mode,
4574                 const unsigned char *old_sha1,
4575                 const unsigned char *new_sha1,
4576                 const char *concatpath,
4577                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4578{
4579        struct diff_filespec *one, *two;
4580
4581        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4582            is_submodule_ignored(concatpath, options))
4583                return;
4584
4585        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4586                unsigned tmp;
4587                const unsigned char *tmp_c;
4588                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4589                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4590                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4591                        new_dirty_submodule = tmp;
4592        }
4593
4594        if (options->prefix &&
4595            strncmp(concatpath, options->prefix, options->prefix_length))
4596                return;
4597
4598        one = alloc_filespec(concatpath);
4599        two = alloc_filespec(concatpath);
4600        fill_filespec(one, old_sha1, old_mode);
4601        fill_filespec(two, new_sha1, new_mode);
4602        one->dirty_submodule = old_dirty_submodule;
4603        two->dirty_submodule = new_dirty_submodule;
4604
4605        diff_queue(&diff_queued_diff, one, two);
4606        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4607                DIFF_OPT_SET(options, HAS_CHANGES);
4608}
4609
4610struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4611{
4612        struct diff_filepair *pair;
4613        struct diff_filespec *one, *two;
4614
4615        if (options->prefix &&
4616            strncmp(path, options->prefix, options->prefix_length))
4617                return NULL;
4618
4619        one = alloc_filespec(path);
4620        two = alloc_filespec(path);
4621        pair = diff_queue(&diff_queued_diff, one, two);
4622        pair->is_unmerged = 1;
4623        return pair;
4624}
4625
4626static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4627                size_t *outsize)
4628{
4629        struct diff_tempfile *temp;
4630        const char *argv[3];
4631        const char **arg = argv;
4632        struct child_process child;
4633        struct strbuf buf = STRBUF_INIT;
4634        int err = 0;
4635
4636        temp = prepare_temp_file(spec->path, spec);
4637        *arg++ = pgm;
4638        *arg++ = temp->name;
4639        *arg = NULL;
4640
4641        memset(&child, 0, sizeof(child));
4642        child.use_shell = 1;
4643        child.argv = argv;
4644        child.out = -1;
4645        if (start_command(&child)) {
4646                remove_tempfile();
4647                return NULL;
4648        }
4649
4650        if (strbuf_read(&buf, child.out, 0) < 0)
4651                err = error("error reading from textconv command '%s'", pgm);
4652        close(child.out);
4653
4654        if (finish_command(&child) || err) {
4655                strbuf_release(&buf);
4656                remove_tempfile();
4657                return NULL;
4658        }
4659        remove_tempfile();
4660
4661        return strbuf_detach(&buf, outsize);
4662}
4663
4664size_t fill_textconv(struct userdiff_driver *driver,
4665                     struct diff_filespec *df,
4666                     char **outbuf)
4667{
4668        size_t size;
4669
4670        if (!driver || !driver->textconv) {
4671                if (!DIFF_FILE_VALID(df)) {
4672                        *outbuf = "";
4673                        return 0;
4674                }
4675                if (diff_populate_filespec(df, 0))
4676                        die("unable to read files to diff");
4677                *outbuf = df->data;
4678                return df->size;
4679        }
4680
4681        if (driver->textconv_cache && df->sha1_valid) {
4682                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4683                                          &size);
4684                if (*outbuf)
4685                        return size;
4686        }
4687
4688        *outbuf = run_textconv(driver->textconv, df, &size);
4689        if (!*outbuf)
4690                die("unable to read files to diff");
4691
4692        if (driver->textconv_cache && df->sha1_valid) {
4693                /* ignore errors, as we might be in a readonly repository */
4694                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4695                                size);
4696                /*
4697                 * we could save up changes and flush them all at the end,
4698                 * but we would need an extra call after all diffing is done.
4699                 * Since generating a cache entry is the slow path anyway,
4700                 * this extra overhead probably isn't a big deal.
4701                 */
4702                notes_cache_write(driver->textconv_cache);
4703        }
4704
4705        return size;
4706}