70464d9d642b316ffb8ab0365591dad8ca78f276
   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{
  72        const char *p = params;
  73        while (*p) {
  74                if (!prefixcmp(p, "changes")) {
  75                        p += 7;
  76                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  77                } else if (!prefixcmp(p, "files")) {
  78                        p += 5;
  79                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  80                } else if (!prefixcmp(p, "noncumulative")) {
  81                        p += 13;
  82                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  83                } else if (!prefixcmp(p, "cumulative")) {
  84                        p += 10;
  85                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  86                } else if (isdigit(*p)) {
  87                        char *end;
  88                        options->dirstat_permille = strtoul(p, &end, 10) * 10;
  89                        p = end;
  90                        if (*p == '.' && isdigit(*++p)) {
  91                                /* only use first digit */
  92                                options->dirstat_permille += *p - '0';
  93                                /* .. and ignore any further digits */
  94                                while (isdigit(*++p))
  95                                        ; /* nothing */
  96                        }
  97                } else
  98                        return error("Unknown --dirstat parameter '%s'", p);
  99
 100                if (*p) {
 101                        /* more parameters, swallow separator */
 102                        if (*p != ',')
 103                                return error("Missing comma separator at char "
 104                                        "%"PRIuMAX" of '%s'",
 105                                        (uintmax_t) (p - params), params);
 106                        p++;
 107                }
 108        }
 109        return 0;
 110}
 111
 112static int git_config_rename(const char *var, const char *value)
 113{
 114        if (!value)
 115                return DIFF_DETECT_RENAME;
 116        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 117                return  DIFF_DETECT_COPY;
 118        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 119}
 120
 121/*
 122 * These are to give UI layer defaults.
 123 * The core-level commands such as git-diff-files should
 124 * never be affected by the setting of diff.renames
 125 * the user happens to have in the configuration file.
 126 */
 127int git_diff_ui_config(const char *var, const char *value, void *cb)
 128{
 129        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 130                diff_use_color_default = git_config_colorbool(var, value, -1);
 131                return 0;
 132        }
 133        if (!strcmp(var, "diff.renames")) {
 134                diff_detect_rename_default = git_config_rename(var, value);
 135                return 0;
 136        }
 137        if (!strcmp(var, "diff.autorefreshindex")) {
 138                diff_auto_refresh_index = git_config_bool(var, value);
 139                return 0;
 140        }
 141        if (!strcmp(var, "diff.mnemonicprefix")) {
 142                diff_mnemonic_prefix = git_config_bool(var, value);
 143                return 0;
 144        }
 145        if (!strcmp(var, "diff.noprefix")) {
 146                diff_no_prefix = git_config_bool(var, value);
 147                return 0;
 148        }
 149        if (!strcmp(var, "diff.external"))
 150                return git_config_string(&external_diff_cmd_cfg, var, value);
 151        if (!strcmp(var, "diff.wordregex"))
 152                return git_config_string(&diff_word_regex_cfg, var, value);
 153
 154        if (!strcmp(var, "diff.ignoresubmodules"))
 155                handle_ignore_submodules_arg(&default_diff_options, value);
 156
 157        return git_diff_basic_config(var, value, cb);
 158}
 159
 160int git_diff_basic_config(const char *var, const char *value, void *cb)
 161{
 162        if (!strcmp(var, "diff.renamelimit")) {
 163                diff_rename_limit_default = git_config_int(var, value);
 164                return 0;
 165        }
 166
 167        switch (userdiff_config(var, value)) {
 168                case 0: break;
 169                case -1: return -1;
 170                default: return 0;
 171        }
 172
 173        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 174                int slot = parse_diff_color_slot(var, 11);
 175                if (slot < 0)
 176                        return 0;
 177                if (!value)
 178                        return config_error_nonbool(var);
 179                color_parse(value, var, diff_colors[slot]);
 180                return 0;
 181        }
 182
 183        /* like GNU diff's --suppress-blank-empty option  */
 184        if (!strcmp(var, "diff.suppressblankempty") ||
 185                        /* for backwards compatibility */
 186                        !strcmp(var, "diff.suppress-blank-empty")) {
 187                diff_suppress_blank_empty = git_config_bool(var, value);
 188                return 0;
 189        }
 190
 191        if (!strcmp(var, "diff.dirstat")) {
 192                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 193                (void) parse_dirstat_params(&default_diff_options, value);
 194                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 195                return 0;
 196        }
 197
 198        if (!prefixcmp(var, "submodule."))
 199                return parse_submodule_config_option(var, value);
 200
 201        return git_color_default_config(var, value, cb);
 202}
 203
 204static char *quote_two(const char *one, const char *two)
 205{
 206        int need_one = quote_c_style(one, NULL, NULL, 1);
 207        int need_two = quote_c_style(two, NULL, NULL, 1);
 208        struct strbuf res = STRBUF_INIT;
 209
 210        if (need_one + need_two) {
 211                strbuf_addch(&res, '"');
 212                quote_c_style(one, &res, NULL, 1);
 213                quote_c_style(two, &res, NULL, 1);
 214                strbuf_addch(&res, '"');
 215        } else {
 216                strbuf_addstr(&res, one);
 217                strbuf_addstr(&res, two);
 218        }
 219        return strbuf_detach(&res, NULL);
 220}
 221
 222static const char *external_diff(void)
 223{
 224        static const char *external_diff_cmd = NULL;
 225        static int done_preparing = 0;
 226
 227        if (done_preparing)
 228                return external_diff_cmd;
 229        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 230        if (!external_diff_cmd)
 231                external_diff_cmd = external_diff_cmd_cfg;
 232        done_preparing = 1;
 233        return external_diff_cmd;
 234}
 235
 236static struct diff_tempfile {
 237        const char *name; /* filename external diff should read from */
 238        char hex[41];
 239        char mode[10];
 240        char tmp_path[PATH_MAX];
 241} diff_temp[2];
 242
 243typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 244
 245struct emit_callback {
 246        int color_diff;
 247        unsigned ws_rule;
 248        int blank_at_eof_in_preimage;
 249        int blank_at_eof_in_postimage;
 250        int lno_in_preimage;
 251        int lno_in_postimage;
 252        sane_truncate_fn truncate;
 253        const char **label_path;
 254        struct diff_words_data *diff_words;
 255        struct diff_options *opt;
 256        int *found_changesp;
 257        struct strbuf *header;
 258};
 259
 260static int count_lines(const char *data, int size)
 261{
 262        int count, ch, completely_empty = 1, nl_just_seen = 0;
 263        count = 0;
 264        while (0 < size--) {
 265                ch = *data++;
 266                if (ch == '\n') {
 267                        count++;
 268                        nl_just_seen = 1;
 269                        completely_empty = 0;
 270                }
 271                else {
 272                        nl_just_seen = 0;
 273                        completely_empty = 0;
 274                }
 275        }
 276        if (completely_empty)
 277                return 0;
 278        if (!nl_just_seen)
 279                count++; /* no trailing newline */
 280        return count;
 281}
 282
 283static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 284{
 285        if (!DIFF_FILE_VALID(one)) {
 286                mf->ptr = (char *)""; /* does not matter */
 287                mf->size = 0;
 288                return 0;
 289        }
 290        else if (diff_populate_filespec(one, 0))
 291                return -1;
 292
 293        mf->ptr = one->data;
 294        mf->size = one->size;
 295        return 0;
 296}
 297
 298/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 299static unsigned long diff_filespec_size(struct diff_filespec *one)
 300{
 301        if (!DIFF_FILE_VALID(one))
 302                return 0;
 303        diff_populate_filespec(one, 1);
 304        return one->size;
 305}
 306
 307static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 308{
 309        char *ptr = mf->ptr;
 310        long size = mf->size;
 311        int cnt = 0;
 312
 313        if (!size)
 314                return cnt;
 315        ptr += size - 1; /* pointing at the very end */
 316        if (*ptr != '\n')
 317                ; /* incomplete line */
 318        else
 319                ptr--; /* skip the last LF */
 320        while (mf->ptr < ptr) {
 321                char *prev_eol;
 322                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 323                        if (*prev_eol == '\n')
 324                                break;
 325                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 326                        break;
 327                cnt++;
 328                ptr = prev_eol - 1;
 329        }
 330        return cnt;
 331}
 332
 333static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 334                               struct emit_callback *ecbdata)
 335{
 336        int l1, l2, at;
 337        unsigned ws_rule = ecbdata->ws_rule;
 338        l1 = count_trailing_blank(mf1, ws_rule);
 339        l2 = count_trailing_blank(mf2, ws_rule);
 340        if (l2 <= l1) {
 341                ecbdata->blank_at_eof_in_preimage = 0;
 342                ecbdata->blank_at_eof_in_postimage = 0;
 343                return;
 344        }
 345        at = count_lines(mf1->ptr, mf1->size);
 346        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 347
 348        at = count_lines(mf2->ptr, mf2->size);
 349        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 350}
 351
 352static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 353                        int first, const char *line, int len)
 354{
 355        int has_trailing_newline, has_trailing_carriage_return;
 356        int nofirst;
 357        FILE *file = o->file;
 358
 359        if (o->output_prefix) {
 360                struct strbuf *msg = NULL;
 361                msg = o->output_prefix(o, o->output_prefix_data);
 362                assert(msg);
 363                fwrite(msg->buf, msg->len, 1, file);
 364        }
 365
 366        if (len == 0) {
 367                has_trailing_newline = (first == '\n');
 368                has_trailing_carriage_return = (!has_trailing_newline &&
 369                                                (first == '\r'));
 370                nofirst = has_trailing_newline || has_trailing_carriage_return;
 371        } else {
 372                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 373                if (has_trailing_newline)
 374                        len--;
 375                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 376                if (has_trailing_carriage_return)
 377                        len--;
 378                nofirst = 0;
 379        }
 380
 381        if (len || !nofirst) {
 382                fputs(set, file);
 383                if (!nofirst)
 384                        fputc(first, file);
 385                fwrite(line, len, 1, file);
 386                fputs(reset, file);
 387        }
 388        if (has_trailing_carriage_return)
 389                fputc('\r', file);
 390        if (has_trailing_newline)
 391                fputc('\n', file);
 392}
 393
 394static void emit_line(struct diff_options *o, const char *set, const char *reset,
 395                      const char *line, int len)
 396{
 397        emit_line_0(o, set, reset, line[0], line+1, len-1);
 398}
 399
 400static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 401{
 402        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 403              ecbdata->blank_at_eof_in_preimage &&
 404              ecbdata->blank_at_eof_in_postimage &&
 405              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 406              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 407                return 0;
 408        return ws_blank_line(line, len, ecbdata->ws_rule);
 409}
 410
 411static void emit_add_line(const char *reset,
 412                          struct emit_callback *ecbdata,
 413                          const char *line, int len)
 414{
 415        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 416        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 417
 418        if (!*ws)
 419                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 420        else if (new_blank_line_at_eof(ecbdata, line, len))
 421                /* Blank line at EOF - paint '+' as well */
 422                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 423        else {
 424                /* Emit just the prefix, then the rest. */
 425                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 426                ws_check_emit(line, len, ecbdata->ws_rule,
 427                              ecbdata->opt->file, set, reset, ws);
 428        }
 429}
 430
 431static void emit_hunk_header(struct emit_callback *ecbdata,
 432                             const char *line, int len)
 433{
 434        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 435        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 436        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 437        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 438        static const char atat[2] = { '@', '@' };
 439        const char *cp, *ep;
 440        struct strbuf msgbuf = STRBUF_INIT;
 441        int org_len = len;
 442        int i = 1;
 443
 444        /*
 445         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 446         * it always is at least 10 bytes long.
 447         */
 448        if (len < 10 ||
 449            memcmp(line, atat, 2) ||
 450            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 451                emit_line(ecbdata->opt, plain, reset, line, len);
 452                return;
 453        }
 454        ep += 2; /* skip over @@ */
 455
 456        /* The hunk header in fraginfo color */
 457        strbuf_add(&msgbuf, frag, strlen(frag));
 458        strbuf_add(&msgbuf, line, ep - line);
 459        strbuf_add(&msgbuf, reset, strlen(reset));
 460
 461        /*
 462         * trailing "\r\n"
 463         */
 464        for ( ; i < 3; i++)
 465                if (line[len - i] == '\r' || line[len - i] == '\n')
 466                        len--;
 467
 468        /* blank before the func header */
 469        for (cp = ep; ep - line < len; ep++)
 470                if (*ep != ' ' && *ep != '\t')
 471                        break;
 472        if (ep != cp) {
 473                strbuf_add(&msgbuf, plain, strlen(plain));
 474                strbuf_add(&msgbuf, cp, ep - cp);
 475                strbuf_add(&msgbuf, reset, strlen(reset));
 476        }
 477
 478        if (ep < line + len) {
 479                strbuf_add(&msgbuf, func, strlen(func));
 480                strbuf_add(&msgbuf, ep, line + len - ep);
 481                strbuf_add(&msgbuf, reset, strlen(reset));
 482        }
 483
 484        strbuf_add(&msgbuf, line + len, org_len - len);
 485        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 486        strbuf_release(&msgbuf);
 487}
 488
 489static struct diff_tempfile *claim_diff_tempfile(void) {
 490        int i;
 491        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 492                if (!diff_temp[i].name)
 493                        return diff_temp + i;
 494        die("BUG: diff is failing to clean up its tempfiles");
 495}
 496
 497static int remove_tempfile_installed;
 498
 499static void remove_tempfile(void)
 500{
 501        int i;
 502        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 503                if (diff_temp[i].name == diff_temp[i].tmp_path)
 504                        unlink_or_warn(diff_temp[i].name);
 505                diff_temp[i].name = NULL;
 506        }
 507}
 508
 509static void remove_tempfile_on_signal(int signo)
 510{
 511        remove_tempfile();
 512        sigchain_pop(signo);
 513        raise(signo);
 514}
 515
 516static void print_line_count(FILE *file, int count)
 517{
 518        switch (count) {
 519        case 0:
 520                fprintf(file, "0,0");
 521                break;
 522        case 1:
 523                fprintf(file, "1");
 524                break;
 525        default:
 526                fprintf(file, "1,%d", count);
 527                break;
 528        }
 529}
 530
 531static void emit_rewrite_lines(struct emit_callback *ecb,
 532                               int prefix, const char *data, int size)
 533{
 534        const char *endp = NULL;
 535        static const char *nneof = " No newline at end of file\n";
 536        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 537        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 538
 539        while (0 < size) {
 540                int len;
 541
 542                endp = memchr(data, '\n', size);
 543                len = endp ? (endp - data + 1) : size;
 544                if (prefix != '+') {
 545                        ecb->lno_in_preimage++;
 546                        emit_line_0(ecb->opt, old, reset, '-',
 547                                    data, len);
 548                } else {
 549                        ecb->lno_in_postimage++;
 550                        emit_add_line(reset, ecb, data, len);
 551                }
 552                size -= len;
 553                data += len;
 554        }
 555        if (!endp) {
 556                const char *plain = diff_get_color(ecb->color_diff,
 557                                                   DIFF_PLAIN);
 558                emit_line_0(ecb->opt, plain, reset, '\\',
 559                            nneof, strlen(nneof));
 560        }
 561}
 562
 563static void emit_rewrite_diff(const char *name_a,
 564                              const char *name_b,
 565                              struct diff_filespec *one,
 566                              struct diff_filespec *two,
 567                              struct userdiff_driver *textconv_one,
 568                              struct userdiff_driver *textconv_two,
 569                              struct diff_options *o)
 570{
 571        int lc_a, lc_b;
 572        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 573        const char *name_a_tab, *name_b_tab;
 574        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 575        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 576        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 577        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 578        const char *a_prefix, *b_prefix;
 579        char *data_one, *data_two;
 580        size_t size_one, size_two;
 581        struct emit_callback ecbdata;
 582        char *line_prefix = "";
 583        struct strbuf *msgbuf;
 584
 585        if (o && o->output_prefix) {
 586                msgbuf = o->output_prefix(o, o->output_prefix_data);
 587                line_prefix = msgbuf->buf;
 588        }
 589
 590        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 591                a_prefix = o->b_prefix;
 592                b_prefix = o->a_prefix;
 593        } else {
 594                a_prefix = o->a_prefix;
 595                b_prefix = o->b_prefix;
 596        }
 597
 598        name_a += (*name_a == '/');
 599        name_b += (*name_b == '/');
 600        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 601        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 602
 603        strbuf_reset(&a_name);
 604        strbuf_reset(&b_name);
 605        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 606        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 607
 608        size_one = fill_textconv(textconv_one, one, &data_one);
 609        size_two = fill_textconv(textconv_two, two, &data_two);
 610
 611        memset(&ecbdata, 0, sizeof(ecbdata));
 612        ecbdata.color_diff = color_diff;
 613        ecbdata.found_changesp = &o->found_changes;
 614        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 615        ecbdata.opt = o;
 616        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 617                mmfile_t mf1, mf2;
 618                mf1.ptr = (char *)data_one;
 619                mf2.ptr = (char *)data_two;
 620                mf1.size = size_one;
 621                mf2.size = size_two;
 622                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 623        }
 624        ecbdata.lno_in_preimage = 1;
 625        ecbdata.lno_in_postimage = 1;
 626
 627        lc_a = count_lines(data_one, size_one);
 628        lc_b = count_lines(data_two, size_two);
 629        fprintf(o->file,
 630                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 631                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 632                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 633                line_prefix, fraginfo);
 634        if (!o->irreversible_delete)
 635                print_line_count(o->file, lc_a);
 636        else
 637                fprintf(o->file, "?,?");
 638        fprintf(o->file, " +");
 639        print_line_count(o->file, lc_b);
 640        fprintf(o->file, " @@%s\n", reset);
 641        if (lc_a && !o->irreversible_delete)
 642                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 643        if (lc_b)
 644                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 645        if (textconv_one)
 646                free((char *)data_one);
 647        if (textconv_two)
 648                free((char *)data_two);
 649}
 650
 651struct diff_words_buffer {
 652        mmfile_t text;
 653        long alloc;
 654        struct diff_words_orig {
 655                const char *begin, *end;
 656        } *orig;
 657        int orig_nr, orig_alloc;
 658};
 659
 660static void diff_words_append(char *line, unsigned long len,
 661                struct diff_words_buffer *buffer)
 662{
 663        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 664        line++;
 665        len--;
 666        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 667        buffer->text.size += len;
 668        buffer->text.ptr[buffer->text.size] = '\0';
 669}
 670
 671struct diff_words_style_elem {
 672        const char *prefix;
 673        const char *suffix;
 674        const char *color; /* NULL; filled in by the setup code if
 675                            * color is enabled */
 676};
 677
 678struct diff_words_style {
 679        enum diff_words_type type;
 680        struct diff_words_style_elem new, old, ctx;
 681        const char *newline;
 682};
 683
 684static struct diff_words_style diff_words_styles[] = {
 685        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 686        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 687        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 688};
 689
 690struct diff_words_data {
 691        struct diff_words_buffer minus, plus;
 692        const char *current_plus;
 693        int last_minus;
 694        struct diff_options *opt;
 695        regex_t *word_regex;
 696        enum diff_words_type type;
 697        struct diff_words_style *style;
 698};
 699
 700static int fn_out_diff_words_write_helper(FILE *fp,
 701                                          struct diff_words_style_elem *st_el,
 702                                          const char *newline,
 703                                          size_t count, const char *buf,
 704                                          const char *line_prefix)
 705{
 706        int print = 0;
 707
 708        while (count) {
 709                char *p = memchr(buf, '\n', count);
 710                if (print)
 711                        fputs(line_prefix, fp);
 712                if (p != buf) {
 713                        if (st_el->color && fputs(st_el->color, fp) < 0)
 714                                return -1;
 715                        if (fputs(st_el->prefix, fp) < 0 ||
 716                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 717                            fputs(st_el->suffix, fp) < 0)
 718                                return -1;
 719                        if (st_el->color && *st_el->color
 720                            && fputs(GIT_COLOR_RESET, fp) < 0)
 721                                return -1;
 722                }
 723                if (!p)
 724                        return 0;
 725                if (fputs(newline, fp) < 0)
 726                        return -1;
 727                count -= p + 1 - buf;
 728                buf = p + 1;
 729                print = 1;
 730        }
 731        return 0;
 732}
 733
 734/*
 735 * '--color-words' algorithm can be described as:
 736 *
 737 *   1. collect a the minus/plus lines of a diff hunk, divided into
 738 *      minus-lines and plus-lines;
 739 *
 740 *   2. break both minus-lines and plus-lines into words and
 741 *      place them into two mmfile_t with one word for each line;
 742 *
 743 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 744 *
 745 * And for the common parts of the both file, we output the plus side text.
 746 * diff_words->current_plus is used to trace the current position of the plus file
 747 * which printed. diff_words->last_minus is used to trace the last minus word
 748 * printed.
 749 *
 750 * For '--graph' to work with '--color-words', we need to output the graph prefix
 751 * on each line of color words output. Generally, there are two conditions on
 752 * which we should output the prefix.
 753 *
 754 *   1. diff_words->last_minus == 0 &&
 755 *      diff_words->current_plus == diff_words->plus.text.ptr
 756 *
 757 *      that is: the plus text must start as a new line, and if there is no minus
 758 *      word printed, a graph prefix must be printed.
 759 *
 760 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 761 *      *(diff_words->current_plus - 1) == '\n'
 762 *
 763 *      that is: a graph prefix must be printed following a '\n'
 764 */
 765static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 766{
 767        if ((diff_words->last_minus == 0 &&
 768                diff_words->current_plus == diff_words->plus.text.ptr) ||
 769                (diff_words->current_plus > diff_words->plus.text.ptr &&
 770                *(diff_words->current_plus - 1) == '\n')) {
 771                return 1;
 772        } else {
 773                return 0;
 774        }
 775}
 776
 777static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 778{
 779        struct diff_words_data *diff_words = priv;
 780        struct diff_words_style *style = diff_words->style;
 781        int minus_first, minus_len, plus_first, plus_len;
 782        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 783        struct diff_options *opt = diff_words->opt;
 784        struct strbuf *msgbuf;
 785        char *line_prefix = "";
 786
 787        if (line[0] != '@' || parse_hunk_header(line, len,
 788                        &minus_first, &minus_len, &plus_first, &plus_len))
 789                return;
 790
 791        assert(opt);
 792        if (opt->output_prefix) {
 793                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 794                line_prefix = msgbuf->buf;
 795        }
 796
 797        /* POSIX requires that first be decremented by one if len == 0... */
 798        if (minus_len) {
 799                minus_begin = diff_words->minus.orig[minus_first].begin;
 800                minus_end =
 801                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 802        } else
 803                minus_begin = minus_end =
 804                        diff_words->minus.orig[minus_first].end;
 805
 806        if (plus_len) {
 807                plus_begin = diff_words->plus.orig[plus_first].begin;
 808                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 809        } else
 810                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 811
 812        if (color_words_output_graph_prefix(diff_words)) {
 813                fputs(line_prefix, diff_words->opt->file);
 814        }
 815        if (diff_words->current_plus != plus_begin) {
 816                fn_out_diff_words_write_helper(diff_words->opt->file,
 817                                &style->ctx, style->newline,
 818                                plus_begin - diff_words->current_plus,
 819                                diff_words->current_plus, line_prefix);
 820                if (*(plus_begin - 1) == '\n')
 821                        fputs(line_prefix, diff_words->opt->file);
 822        }
 823        if (minus_begin != minus_end) {
 824                fn_out_diff_words_write_helper(diff_words->opt->file,
 825                                &style->old, style->newline,
 826                                minus_end - minus_begin, minus_begin,
 827                                line_prefix);
 828        }
 829        if (plus_begin != plus_end) {
 830                fn_out_diff_words_write_helper(diff_words->opt->file,
 831                                &style->new, style->newline,
 832                                plus_end - plus_begin, plus_begin,
 833                                line_prefix);
 834        }
 835
 836        diff_words->current_plus = plus_end;
 837        diff_words->last_minus = minus_first;
 838}
 839
 840/* This function starts looking at *begin, and returns 0 iff a word was found. */
 841static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 842                int *begin, int *end)
 843{
 844        if (word_regex && *begin < buffer->size) {
 845                regmatch_t match[1];
 846                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 847                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 848                                        '\n', match[0].rm_eo - match[0].rm_so);
 849                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 850                        *begin += match[0].rm_so;
 851                        return *begin >= *end;
 852                }
 853                return -1;
 854        }
 855
 856        /* find the next word */
 857        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 858                (*begin)++;
 859        if (*begin >= buffer->size)
 860                return -1;
 861
 862        /* find the end of the word */
 863        *end = *begin + 1;
 864        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 865                (*end)++;
 866
 867        return 0;
 868}
 869
 870/*
 871 * This function splits the words in buffer->text, stores the list with
 872 * newline separator into out, and saves the offsets of the original words
 873 * in buffer->orig.
 874 */
 875static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 876                regex_t *word_regex)
 877{
 878        int i, j;
 879        long alloc = 0;
 880
 881        out->size = 0;
 882        out->ptr = NULL;
 883
 884        /* fake an empty "0th" word */
 885        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 886        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 887        buffer->orig_nr = 1;
 888
 889        for (i = 0; i < buffer->text.size; i++) {
 890                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 891                        return;
 892
 893                /* store original boundaries */
 894                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 895                                buffer->orig_alloc);
 896                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 897                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 898                buffer->orig_nr++;
 899
 900                /* store one word */
 901                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 902                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 903                out->ptr[out->size + j - i] = '\n';
 904                out->size += j - i + 1;
 905
 906                i = j - 1;
 907        }
 908}
 909
 910/* this executes the word diff on the accumulated buffers */
 911static void diff_words_show(struct diff_words_data *diff_words)
 912{
 913        xpparam_t xpp;
 914        xdemitconf_t xecfg;
 915        mmfile_t minus, plus;
 916        struct diff_words_style *style = diff_words->style;
 917
 918        struct diff_options *opt = diff_words->opt;
 919        struct strbuf *msgbuf;
 920        char *line_prefix = "";
 921
 922        assert(opt);
 923        if (opt->output_prefix) {
 924                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 925                line_prefix = msgbuf->buf;
 926        }
 927
 928        /* special case: only removal */
 929        if (!diff_words->plus.text.size) {
 930                fputs(line_prefix, diff_words->opt->file);
 931                fn_out_diff_words_write_helper(diff_words->opt->file,
 932                        &style->old, style->newline,
 933                        diff_words->minus.text.size,
 934                        diff_words->minus.text.ptr, line_prefix);
 935                diff_words->minus.text.size = 0;
 936                return;
 937        }
 938
 939        diff_words->current_plus = diff_words->plus.text.ptr;
 940        diff_words->last_minus = 0;
 941
 942        memset(&xpp, 0, sizeof(xpp));
 943        memset(&xecfg, 0, sizeof(xecfg));
 944        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 945        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 946        xpp.flags = 0;
 947        /* as only the hunk header will be parsed, we need a 0-context */
 948        xecfg.ctxlen = 0;
 949        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 950                      &xpp, &xecfg);
 951        free(minus.ptr);
 952        free(plus.ptr);
 953        if (diff_words->current_plus != diff_words->plus.text.ptr +
 954                        diff_words->plus.text.size) {
 955                if (color_words_output_graph_prefix(diff_words))
 956                        fputs(line_prefix, diff_words->opt->file);
 957                fn_out_diff_words_write_helper(diff_words->opt->file,
 958                        &style->ctx, style->newline,
 959                        diff_words->plus.text.ptr + diff_words->plus.text.size
 960                        - diff_words->current_plus, diff_words->current_plus,
 961                        line_prefix);
 962        }
 963        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 964}
 965
 966/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 967static void diff_words_flush(struct emit_callback *ecbdata)
 968{
 969        if (ecbdata->diff_words->minus.text.size ||
 970            ecbdata->diff_words->plus.text.size)
 971                diff_words_show(ecbdata->diff_words);
 972}
 973
 974static void free_diff_words_data(struct emit_callback *ecbdata)
 975{
 976        if (ecbdata->diff_words) {
 977                diff_words_flush(ecbdata);
 978                free (ecbdata->diff_words->minus.text.ptr);
 979                free (ecbdata->diff_words->minus.orig);
 980                free (ecbdata->diff_words->plus.text.ptr);
 981                free (ecbdata->diff_words->plus.orig);
 982                if (ecbdata->diff_words->word_regex) {
 983                        regfree(ecbdata->diff_words->word_regex);
 984                        free(ecbdata->diff_words->word_regex);
 985                }
 986                free(ecbdata->diff_words);
 987                ecbdata->diff_words = NULL;
 988        }
 989}
 990
 991const char *diff_get_color(int diff_use_color, enum color_diff ix)
 992{
 993        if (diff_use_color)
 994                return diff_colors[ix];
 995        return "";
 996}
 997
 998static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 999{
1000        const char *cp;
1001        unsigned long allot;
1002        size_t l = len;
1003
1004        if (ecb->truncate)
1005                return ecb->truncate(line, len);
1006        cp = line;
1007        allot = l;
1008        while (0 < l) {
1009                (void) utf8_width(&cp, &l);
1010                if (!cp)
1011                        break; /* truncated in the middle? */
1012        }
1013        return allot - l;
1014}
1015
1016static void find_lno(const char *line, struct emit_callback *ecbdata)
1017{
1018        const char *p;
1019        ecbdata->lno_in_preimage = 0;
1020        ecbdata->lno_in_postimage = 0;
1021        p = strchr(line, '-');
1022        if (!p)
1023                return; /* cannot happen */
1024        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1025        p = strchr(p, '+');
1026        if (!p)
1027                return; /* cannot happen */
1028        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1029}
1030
1031static void fn_out_consume(void *priv, char *line, unsigned long len)
1032{
1033        struct emit_callback *ecbdata = priv;
1034        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1035        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1036        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1037        struct diff_options *o = ecbdata->opt;
1038        char *line_prefix = "";
1039        struct strbuf *msgbuf;
1040
1041        if (o && o->output_prefix) {
1042                msgbuf = o->output_prefix(o, o->output_prefix_data);
1043                line_prefix = msgbuf->buf;
1044        }
1045
1046        if (ecbdata->header) {
1047                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1048                strbuf_reset(ecbdata->header);
1049                ecbdata->header = NULL;
1050        }
1051        *(ecbdata->found_changesp) = 1;
1052
1053        if (ecbdata->label_path[0]) {
1054                const char *name_a_tab, *name_b_tab;
1055
1056                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1057                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1058
1059                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1060                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1061                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1062                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1063                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1064        }
1065
1066        if (diff_suppress_blank_empty
1067            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1068                line[0] = '\n';
1069                len = 1;
1070        }
1071
1072        if (line[0] == '@') {
1073                if (ecbdata->diff_words)
1074                        diff_words_flush(ecbdata);
1075                len = sane_truncate_line(ecbdata, line, len);
1076                find_lno(line, ecbdata);
1077                emit_hunk_header(ecbdata, line, len);
1078                if (line[len-1] != '\n')
1079                        putc('\n', ecbdata->opt->file);
1080                return;
1081        }
1082
1083        if (len < 1) {
1084                emit_line(ecbdata->opt, reset, reset, line, len);
1085                if (ecbdata->diff_words
1086                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1087                        fputs("~\n", ecbdata->opt->file);
1088                return;
1089        }
1090
1091        if (ecbdata->diff_words) {
1092                if (line[0] == '-') {
1093                        diff_words_append(line, len,
1094                                          &ecbdata->diff_words->minus);
1095                        return;
1096                } else if (line[0] == '+') {
1097                        diff_words_append(line, len,
1098                                          &ecbdata->diff_words->plus);
1099                        return;
1100                }
1101                diff_words_flush(ecbdata);
1102                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1103                        emit_line(ecbdata->opt, plain, reset, line, len);
1104                        fputs("~\n", ecbdata->opt->file);
1105                } else {
1106                        /* don't print the prefix character */
1107                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1108                }
1109                return;
1110        }
1111
1112        if (line[0] != '+') {
1113                const char *color =
1114                        diff_get_color(ecbdata->color_diff,
1115                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1116                ecbdata->lno_in_preimage++;
1117                if (line[0] == ' ')
1118                        ecbdata->lno_in_postimage++;
1119                emit_line(ecbdata->opt, color, reset, line, len);
1120        } else {
1121                ecbdata->lno_in_postimage++;
1122                emit_add_line(reset, ecbdata, line + 1, len - 1);
1123        }
1124}
1125
1126static char *pprint_rename(const char *a, const char *b)
1127{
1128        const char *old = a;
1129        const char *new = b;
1130        struct strbuf name = STRBUF_INIT;
1131        int pfx_length, sfx_length;
1132        int len_a = strlen(a);
1133        int len_b = strlen(b);
1134        int a_midlen, b_midlen;
1135        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1136        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1137
1138        if (qlen_a || qlen_b) {
1139                quote_c_style(a, &name, NULL, 0);
1140                strbuf_addstr(&name, " => ");
1141                quote_c_style(b, &name, NULL, 0);
1142                return strbuf_detach(&name, NULL);
1143        }
1144
1145        /* Find common prefix */
1146        pfx_length = 0;
1147        while (*old && *new && *old == *new) {
1148                if (*old == '/')
1149                        pfx_length = old - a + 1;
1150                old++;
1151                new++;
1152        }
1153
1154        /* Find common suffix */
1155        old = a + len_a;
1156        new = b + len_b;
1157        sfx_length = 0;
1158        while (a <= old && b <= new && *old == *new) {
1159                if (*old == '/')
1160                        sfx_length = len_a - (old - a);
1161                old--;
1162                new--;
1163        }
1164
1165        /*
1166         * pfx{mid-a => mid-b}sfx
1167         * {pfx-a => pfx-b}sfx
1168         * pfx{sfx-a => sfx-b}
1169         * name-a => name-b
1170         */
1171        a_midlen = len_a - pfx_length - sfx_length;
1172        b_midlen = len_b - pfx_length - sfx_length;
1173        if (a_midlen < 0)
1174                a_midlen = 0;
1175        if (b_midlen < 0)
1176                b_midlen = 0;
1177
1178        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1179        if (pfx_length + sfx_length) {
1180                strbuf_add(&name, a, pfx_length);
1181                strbuf_addch(&name, '{');
1182        }
1183        strbuf_add(&name, a + pfx_length, a_midlen);
1184        strbuf_addstr(&name, " => ");
1185        strbuf_add(&name, b + pfx_length, b_midlen);
1186        if (pfx_length + sfx_length) {
1187                strbuf_addch(&name, '}');
1188                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1189        }
1190        return strbuf_detach(&name, NULL);
1191}
1192
1193struct diffstat_t {
1194        int nr;
1195        int alloc;
1196        struct diffstat_file {
1197                char *from_name;
1198                char *name;
1199                char *print_name;
1200                unsigned is_unmerged:1;
1201                unsigned is_binary:1;
1202                unsigned is_renamed:1;
1203                uintmax_t added, deleted;
1204        } **files;
1205};
1206
1207static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1208                                          const char *name_a,
1209                                          const char *name_b)
1210{
1211        struct diffstat_file *x;
1212        x = xcalloc(sizeof (*x), 1);
1213        if (diffstat->nr == diffstat->alloc) {
1214                diffstat->alloc = alloc_nr(diffstat->alloc);
1215                diffstat->files = xrealloc(diffstat->files,
1216                                diffstat->alloc * sizeof(x));
1217        }
1218        diffstat->files[diffstat->nr++] = x;
1219        if (name_b) {
1220                x->from_name = xstrdup(name_a);
1221                x->name = xstrdup(name_b);
1222                x->is_renamed = 1;
1223        }
1224        else {
1225                x->from_name = NULL;
1226                x->name = xstrdup(name_a);
1227        }
1228        return x;
1229}
1230
1231static void diffstat_consume(void *priv, char *line, unsigned long len)
1232{
1233        struct diffstat_t *diffstat = priv;
1234        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1235
1236        if (line[0] == '+')
1237                x->added++;
1238        else if (line[0] == '-')
1239                x->deleted++;
1240}
1241
1242const char mime_boundary_leader[] = "------------";
1243
1244static int scale_linear(int it, int width, int max_change)
1245{
1246        /*
1247         * make sure that at least one '-' is printed if there were deletions,
1248         * and likewise for '+'.
1249         */
1250        if (max_change < 2)
1251                return it;
1252        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1253}
1254
1255static void show_name(FILE *file,
1256                      const char *prefix, const char *name, int len)
1257{
1258        fprintf(file, " %s%-*s |", prefix, len, name);
1259}
1260
1261static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1262{
1263        if (cnt <= 0)
1264                return;
1265        fprintf(file, "%s", set);
1266        while (cnt--)
1267                putc(ch, file);
1268        fprintf(file, "%s", reset);
1269}
1270
1271static void fill_print_name(struct diffstat_file *file)
1272{
1273        char *pname;
1274
1275        if (file->print_name)
1276                return;
1277
1278        if (!file->is_renamed) {
1279                struct strbuf buf = STRBUF_INIT;
1280                if (quote_c_style(file->name, &buf, NULL, 0)) {
1281                        pname = strbuf_detach(&buf, NULL);
1282                } else {
1283                        pname = file->name;
1284                        strbuf_release(&buf);
1285                }
1286        } else {
1287                pname = pprint_rename(file->from_name, file->name);
1288        }
1289        file->print_name = pname;
1290}
1291
1292static void show_stats(struct diffstat_t *data, struct diff_options *options)
1293{
1294        int i, len, add, del, adds = 0, dels = 0;
1295        uintmax_t max_change = 0, max_len = 0;
1296        int total_files = data->nr;
1297        int width, name_width;
1298        const char *reset, *add_c, *del_c;
1299        const char *line_prefix = "";
1300        struct strbuf *msg = NULL;
1301
1302        if (data->nr == 0)
1303                return;
1304
1305        if (options->output_prefix) {
1306                msg = options->output_prefix(options, options->output_prefix_data);
1307                line_prefix = msg->buf;
1308        }
1309
1310        width = options->stat_width ? options->stat_width : 80;
1311        name_width = options->stat_name_width ? options->stat_name_width : 50;
1312
1313        /* Sanity: give at least 5 columns to the graph,
1314         * but leave at least 10 columns for the name.
1315         */
1316        if (width < 25)
1317                width = 25;
1318        if (name_width < 10)
1319                name_width = 10;
1320        else if (width < name_width + 15)
1321                name_width = width - 15;
1322
1323        /* Find the longest filename and max number of changes */
1324        reset = diff_get_color_opt(options, DIFF_RESET);
1325        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1326        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1327
1328        for (i = 0; i < data->nr; i++) {
1329                struct diffstat_file *file = data->files[i];
1330                uintmax_t change = file->added + file->deleted;
1331                fill_print_name(file);
1332                len = strlen(file->print_name);
1333                if (max_len < len)
1334                        max_len = len;
1335
1336                if (file->is_binary || file->is_unmerged)
1337                        continue;
1338                if (max_change < change)
1339                        max_change = change;
1340        }
1341
1342        /* Compute the width of the graph part;
1343         * 10 is for one blank at the beginning of the line plus
1344         * " | count " between the name and the graph.
1345         *
1346         * From here on, name_width is the width of the name area,
1347         * and width is the width of the graph area.
1348         */
1349        name_width = (name_width < max_len) ? name_width : max_len;
1350        if (width < (name_width + 10) + max_change)
1351                width = width - (name_width + 10);
1352        else
1353                width = max_change;
1354
1355        for (i = 0; i < data->nr; i++) {
1356                const char *prefix = "";
1357                char *name = data->files[i]->print_name;
1358                uintmax_t added = data->files[i]->added;
1359                uintmax_t deleted = data->files[i]->deleted;
1360                int name_len;
1361
1362                /*
1363                 * "scale" the filename
1364                 */
1365                len = name_width;
1366                name_len = strlen(name);
1367                if (name_width < name_len) {
1368                        char *slash;
1369                        prefix = "...";
1370                        len -= 3;
1371                        name += name_len - len;
1372                        slash = strchr(name, '/');
1373                        if (slash)
1374                                name = slash;
1375                }
1376
1377                if (data->files[i]->is_binary) {
1378                        fprintf(options->file, "%s", line_prefix);
1379                        show_name(options->file, prefix, name, len);
1380                        fprintf(options->file, "  Bin ");
1381                        fprintf(options->file, "%s%"PRIuMAX"%s",
1382                                del_c, deleted, reset);
1383                        fprintf(options->file, " -> ");
1384                        fprintf(options->file, "%s%"PRIuMAX"%s",
1385                                add_c, added, reset);
1386                        fprintf(options->file, " bytes");
1387                        fprintf(options->file, "\n");
1388                        continue;
1389                }
1390                else if (data->files[i]->is_unmerged) {
1391                        fprintf(options->file, "%s", line_prefix);
1392                        show_name(options->file, prefix, name, len);
1393                        fprintf(options->file, "  Unmerged\n");
1394                        continue;
1395                }
1396                else if (!data->files[i]->is_renamed &&
1397                         (added + deleted == 0)) {
1398                        total_files--;
1399                        continue;
1400                }
1401
1402                /*
1403                 * scale the add/delete
1404                 */
1405                add = added;
1406                del = deleted;
1407                adds += add;
1408                dels += del;
1409
1410                if (width <= max_change) {
1411                        add = scale_linear(add, width, max_change);
1412                        del = scale_linear(del, width, max_change);
1413                }
1414                fprintf(options->file, "%s", line_prefix);
1415                show_name(options->file, prefix, name, len);
1416                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1417                                added + deleted ? " " : "");
1418                show_graph(options->file, '+', add, add_c, reset);
1419                show_graph(options->file, '-', del, del_c, reset);
1420                fprintf(options->file, "\n");
1421        }
1422        fprintf(options->file, "%s", line_prefix);
1423        fprintf(options->file,
1424               " %d files changed, %d insertions(+), %d deletions(-)\n",
1425               total_files, adds, dels);
1426}
1427
1428static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1429{
1430        int i, adds = 0, dels = 0, total_files = data->nr;
1431
1432        if (data->nr == 0)
1433                return;
1434
1435        for (i = 0; i < data->nr; i++) {
1436                if (!data->files[i]->is_binary &&
1437                    !data->files[i]->is_unmerged) {
1438                        int added = data->files[i]->added;
1439                        int deleted= data->files[i]->deleted;
1440                        if (!data->files[i]->is_renamed &&
1441                            (added + deleted == 0)) {
1442                                total_files--;
1443                        } else {
1444                                adds += added;
1445                                dels += deleted;
1446                        }
1447                }
1448        }
1449        if (options->output_prefix) {
1450                struct strbuf *msg = NULL;
1451                msg = options->output_prefix(options,
1452                                options->output_prefix_data);
1453                fprintf(options->file, "%s", msg->buf);
1454        }
1455        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1456               total_files, adds, dels);
1457}
1458
1459static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1460{
1461        int i;
1462
1463        if (data->nr == 0)
1464                return;
1465
1466        for (i = 0; i < data->nr; i++) {
1467                struct diffstat_file *file = data->files[i];
1468
1469                if (options->output_prefix) {
1470                        struct strbuf *msg = NULL;
1471                        msg = options->output_prefix(options,
1472                                        options->output_prefix_data);
1473                        fprintf(options->file, "%s", msg->buf);
1474                }
1475
1476                if (file->is_binary)
1477                        fprintf(options->file, "-\t-\t");
1478                else
1479                        fprintf(options->file,
1480                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1481                                file->added, file->deleted);
1482                if (options->line_termination) {
1483                        fill_print_name(file);
1484                        if (!file->is_renamed)
1485                                write_name_quoted(file->name, options->file,
1486                                                  options->line_termination);
1487                        else {
1488                                fputs(file->print_name, options->file);
1489                                putc(options->line_termination, options->file);
1490                        }
1491                } else {
1492                        if (file->is_renamed) {
1493                                putc('\0', options->file);
1494                                write_name_quoted(file->from_name, options->file, '\0');
1495                        }
1496                        write_name_quoted(file->name, options->file, '\0');
1497                }
1498        }
1499}
1500
1501struct dirstat_file {
1502        const char *name;
1503        unsigned long changed;
1504};
1505
1506struct dirstat_dir {
1507        struct dirstat_file *files;
1508        int alloc, nr, permille, cumulative;
1509};
1510
1511static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1512                unsigned long changed, const char *base, int baselen)
1513{
1514        unsigned long this_dir = 0;
1515        unsigned int sources = 0;
1516        const char *line_prefix = "";
1517        struct strbuf *msg = NULL;
1518
1519        if (opt->output_prefix) {
1520                msg = opt->output_prefix(opt, opt->output_prefix_data);
1521                line_prefix = msg->buf;
1522        }
1523
1524        while (dir->nr) {
1525                struct dirstat_file *f = dir->files;
1526                int namelen = strlen(f->name);
1527                unsigned long this;
1528                char *slash;
1529
1530                if (namelen < baselen)
1531                        break;
1532                if (memcmp(f->name, base, baselen))
1533                        break;
1534                slash = strchr(f->name + baselen, '/');
1535                if (slash) {
1536                        int newbaselen = slash + 1 - f->name;
1537                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1538                        sources++;
1539                } else {
1540                        this = f->changed;
1541                        dir->files++;
1542                        dir->nr--;
1543                        sources += 2;
1544                }
1545                this_dir += this;
1546        }
1547
1548        /*
1549         * We don't report dirstat's for
1550         *  - the top level
1551         *  - or cases where everything came from a single directory
1552         *    under this directory (sources == 1).
1553         */
1554        if (baselen && sources != 1) {
1555                if (this_dir) {
1556                        int permille = this_dir * 1000 / changed;
1557                        if (permille >= dir->permille) {
1558                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1559                                        permille / 10, permille % 10, baselen, base);
1560                                if (!dir->cumulative)
1561                                        return 0;
1562                        }
1563                }
1564        }
1565        return this_dir;
1566}
1567
1568static int dirstat_compare(const void *_a, const void *_b)
1569{
1570        const struct dirstat_file *a = _a;
1571        const struct dirstat_file *b = _b;
1572        return strcmp(a->name, b->name);
1573}
1574
1575static void show_dirstat(struct diff_options *options)
1576{
1577        int i;
1578        unsigned long changed;
1579        struct dirstat_dir dir;
1580        struct diff_queue_struct *q = &diff_queued_diff;
1581
1582        dir.files = NULL;
1583        dir.alloc = 0;
1584        dir.nr = 0;
1585        dir.permille = options->dirstat_permille;
1586        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1587
1588        changed = 0;
1589        for (i = 0; i < q->nr; i++) {
1590                struct diff_filepair *p = q->queue[i];
1591                const char *name;
1592                unsigned long copied, added, damage;
1593                int content_changed;
1594
1595                name = p->two->path ? p->two->path : p->one->path;
1596
1597                if (p->one->sha1_valid && p->two->sha1_valid)
1598                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1599                else
1600                        content_changed = 1;
1601
1602                if (!content_changed) {
1603                        /*
1604                         * The SHA1 has not changed, so pre-/post-content is
1605                         * identical. We can therefore skip looking at the
1606                         * file contents altogether.
1607                         */
1608                        damage = 0;
1609                        goto found_damage;
1610                }
1611
1612                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1613                        /*
1614                         * In --dirstat-by-file mode, we don't really need to
1615                         * look at the actual file contents at all.
1616                         * The fact that the SHA1 changed is enough for us to
1617                         * add this file to the list of results
1618                         * (with each file contributing equal damage).
1619                         */
1620                        damage = 1;
1621                        goto found_damage;
1622                }
1623
1624                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1625                        diff_populate_filespec(p->one, 0);
1626                        diff_populate_filespec(p->two, 0);
1627                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1628                                               &copied, &added);
1629                        diff_free_filespec_data(p->one);
1630                        diff_free_filespec_data(p->two);
1631                } else if (DIFF_FILE_VALID(p->one)) {
1632                        diff_populate_filespec(p->one, 1);
1633                        copied = added = 0;
1634                        diff_free_filespec_data(p->one);
1635                } else if (DIFF_FILE_VALID(p->two)) {
1636                        diff_populate_filespec(p->two, 1);
1637                        copied = 0;
1638                        added = p->two->size;
1639                        diff_free_filespec_data(p->two);
1640                } else
1641                        continue;
1642
1643                /*
1644                 * Original minus copied is the removed material,
1645                 * added is the new material.  They are both damages
1646                 * made to the preimage.
1647                 * If the resulting damage is zero, we know that
1648                 * diffcore_count_changes() considers the two entries to
1649                 * be identical, but since content_changed is true, we
1650                 * know that there must have been _some_ kind of change,
1651                 * so we force all entries to have damage > 0.
1652                 */
1653                damage = (p->one->size - copied) + added;
1654                if (!damage)
1655                        damage = 1;
1656
1657found_damage:
1658                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1659                dir.files[dir.nr].name = name;
1660                dir.files[dir.nr].changed = damage;
1661                changed += damage;
1662                dir.nr++;
1663        }
1664
1665        /* This can happen even with many files, if everything was renames */
1666        if (!changed)
1667                return;
1668
1669        /* Show all directories with more than x% of the changes */
1670        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1671        gather_dirstat(options, &dir, changed, "", 0);
1672}
1673
1674static void free_diffstat_info(struct diffstat_t *diffstat)
1675{
1676        int i;
1677        for (i = 0; i < diffstat->nr; i++) {
1678                struct diffstat_file *f = diffstat->files[i];
1679                if (f->name != f->print_name)
1680                        free(f->print_name);
1681                free(f->name);
1682                free(f->from_name);
1683                free(f);
1684        }
1685        free(diffstat->files);
1686}
1687
1688struct checkdiff_t {
1689        const char *filename;
1690        int lineno;
1691        int conflict_marker_size;
1692        struct diff_options *o;
1693        unsigned ws_rule;
1694        unsigned status;
1695};
1696
1697static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1698{
1699        char firstchar;
1700        int cnt;
1701
1702        if (len < marker_size + 1)
1703                return 0;
1704        firstchar = line[0];
1705        switch (firstchar) {
1706        case '=': case '>': case '<': case '|':
1707                break;
1708        default:
1709                return 0;
1710        }
1711        for (cnt = 1; cnt < marker_size; cnt++)
1712                if (line[cnt] != firstchar)
1713                        return 0;
1714        /* line[1] thru line[marker_size-1] are same as firstchar */
1715        if (len < marker_size + 1 || !isspace(line[marker_size]))
1716                return 0;
1717        return 1;
1718}
1719
1720static void checkdiff_consume(void *priv, char *line, unsigned long len)
1721{
1722        struct checkdiff_t *data = priv;
1723        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1724        int marker_size = data->conflict_marker_size;
1725        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1726        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1727        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1728        char *err;
1729        char *line_prefix = "";
1730        struct strbuf *msgbuf;
1731
1732        assert(data->o);
1733        if (data->o->output_prefix) {
1734                msgbuf = data->o->output_prefix(data->o,
1735                        data->o->output_prefix_data);
1736                line_prefix = msgbuf->buf;
1737        }
1738
1739        if (line[0] == '+') {
1740                unsigned bad;
1741                data->lineno++;
1742                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1743                        data->status |= 1;
1744                        fprintf(data->o->file,
1745                                "%s%s:%d: leftover conflict marker\n",
1746                                line_prefix, data->filename, data->lineno);
1747                }
1748                bad = ws_check(line + 1, len - 1, data->ws_rule);
1749                if (!bad)
1750                        return;
1751                data->status |= bad;
1752                err = whitespace_error_string(bad);
1753                fprintf(data->o->file, "%s%s:%d: %s.\n",
1754                        line_prefix, data->filename, data->lineno, err);
1755                free(err);
1756                emit_line(data->o, set, reset, line, 1);
1757                ws_check_emit(line + 1, len - 1, data->ws_rule,
1758                              data->o->file, set, reset, ws);
1759        } else if (line[0] == ' ') {
1760                data->lineno++;
1761        } else if (line[0] == '@') {
1762                char *plus = strchr(line, '+');
1763                if (plus)
1764                        data->lineno = strtol(plus, NULL, 10) - 1;
1765                else
1766                        die("invalid diff");
1767        }
1768}
1769
1770static unsigned char *deflate_it(char *data,
1771                                 unsigned long size,
1772                                 unsigned long *result_size)
1773{
1774        int bound;
1775        unsigned char *deflated;
1776        z_stream stream;
1777
1778        memset(&stream, 0, sizeof(stream));
1779        deflateInit(&stream, zlib_compression_level);
1780        bound = deflateBound(&stream, size);
1781        deflated = xmalloc(bound);
1782        stream.next_out = deflated;
1783        stream.avail_out = bound;
1784
1785        stream.next_in = (unsigned char *)data;
1786        stream.avail_in = size;
1787        while (deflate(&stream, Z_FINISH) == Z_OK)
1788                ; /* nothing */
1789        deflateEnd(&stream);
1790        *result_size = stream.total_out;
1791        return deflated;
1792}
1793
1794static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1795{
1796        void *cp;
1797        void *delta;
1798        void *deflated;
1799        void *data;
1800        unsigned long orig_size;
1801        unsigned long delta_size;
1802        unsigned long deflate_size;
1803        unsigned long data_size;
1804
1805        /* We could do deflated delta, or we could do just deflated two,
1806         * whichever is smaller.
1807         */
1808        delta = NULL;
1809        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1810        if (one->size && two->size) {
1811                delta = diff_delta(one->ptr, one->size,
1812                                   two->ptr, two->size,
1813                                   &delta_size, deflate_size);
1814                if (delta) {
1815                        void *to_free = delta;
1816                        orig_size = delta_size;
1817                        delta = deflate_it(delta, delta_size, &delta_size);
1818                        free(to_free);
1819                }
1820        }
1821
1822        if (delta && delta_size < deflate_size) {
1823                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1824                free(deflated);
1825                data = delta;
1826                data_size = delta_size;
1827        }
1828        else {
1829                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1830                free(delta);
1831                data = deflated;
1832                data_size = deflate_size;
1833        }
1834
1835        /* emit data encoded in base85 */
1836        cp = data;
1837        while (data_size) {
1838                int bytes = (52 < data_size) ? 52 : data_size;
1839                char line[70];
1840                data_size -= bytes;
1841                if (bytes <= 26)
1842                        line[0] = bytes + 'A' - 1;
1843                else
1844                        line[0] = bytes - 26 + 'a' - 1;
1845                encode_85(line + 1, cp, bytes);
1846                cp = (char *) cp + bytes;
1847                fprintf(file, "%s", prefix);
1848                fputs(line, file);
1849                fputc('\n', file);
1850        }
1851        fprintf(file, "%s\n", prefix);
1852        free(data);
1853}
1854
1855static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1856{
1857        fprintf(file, "%sGIT binary patch\n", prefix);
1858        emit_binary_diff_body(file, one, two, prefix);
1859        emit_binary_diff_body(file, two, one, prefix);
1860}
1861
1862static void diff_filespec_load_driver(struct diff_filespec *one)
1863{
1864        /* Use already-loaded driver */
1865        if (one->driver)
1866                return;
1867
1868        if (S_ISREG(one->mode))
1869                one->driver = userdiff_find_by_path(one->path);
1870
1871        /* Fallback to default settings */
1872        if (!one->driver)
1873                one->driver = userdiff_find_by_name("default");
1874}
1875
1876int diff_filespec_is_binary(struct diff_filespec *one)
1877{
1878        if (one->is_binary == -1) {
1879                diff_filespec_load_driver(one);
1880                if (one->driver->binary != -1)
1881                        one->is_binary = one->driver->binary;
1882                else {
1883                        if (!one->data && DIFF_FILE_VALID(one))
1884                                diff_populate_filespec(one, 0);
1885                        if (one->data)
1886                                one->is_binary = buffer_is_binary(one->data,
1887                                                one->size);
1888                        if (one->is_binary == -1)
1889                                one->is_binary = 0;
1890                }
1891        }
1892        return one->is_binary;
1893}
1894
1895static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1896{
1897        diff_filespec_load_driver(one);
1898        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1899}
1900
1901static const char *userdiff_word_regex(struct diff_filespec *one)
1902{
1903        diff_filespec_load_driver(one);
1904        return one->driver->word_regex;
1905}
1906
1907void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1908{
1909        if (!options->a_prefix)
1910                options->a_prefix = a;
1911        if (!options->b_prefix)
1912                options->b_prefix = b;
1913}
1914
1915struct userdiff_driver *get_textconv(struct diff_filespec *one)
1916{
1917        if (!DIFF_FILE_VALID(one))
1918                return NULL;
1919
1920        diff_filespec_load_driver(one);
1921        if (!one->driver->textconv)
1922                return NULL;
1923
1924        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1925                struct notes_cache *c = xmalloc(sizeof(*c));
1926                struct strbuf name = STRBUF_INIT;
1927
1928                strbuf_addf(&name, "textconv/%s", one->driver->name);
1929                notes_cache_init(c, name.buf, one->driver->textconv);
1930                one->driver->textconv_cache = c;
1931        }
1932
1933        return one->driver;
1934}
1935
1936static void builtin_diff(const char *name_a,
1937                         const char *name_b,
1938                         struct diff_filespec *one,
1939                         struct diff_filespec *two,
1940                         const char *xfrm_msg,
1941                         int must_show_header,
1942                         struct diff_options *o,
1943                         int complete_rewrite)
1944{
1945        mmfile_t mf1, mf2;
1946        const char *lbl[2];
1947        char *a_one, *b_two;
1948        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1949        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1950        const char *a_prefix, *b_prefix;
1951        struct userdiff_driver *textconv_one = NULL;
1952        struct userdiff_driver *textconv_two = NULL;
1953        struct strbuf header = STRBUF_INIT;
1954        struct strbuf *msgbuf;
1955        char *line_prefix = "";
1956
1957        if (o->output_prefix) {
1958                msgbuf = o->output_prefix(o, o->output_prefix_data);
1959                line_prefix = msgbuf->buf;
1960        }
1961
1962        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1963                        (!one->mode || S_ISGITLINK(one->mode)) &&
1964                        (!two->mode || S_ISGITLINK(two->mode))) {
1965                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1966                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1967                show_submodule_summary(o->file, one ? one->path : two->path,
1968                                one->sha1, two->sha1, two->dirty_submodule,
1969                                del, add, reset);
1970                return;
1971        }
1972
1973        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1974                textconv_one = get_textconv(one);
1975                textconv_two = get_textconv(two);
1976        }
1977
1978        diff_set_mnemonic_prefix(o, "a/", "b/");
1979        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1980                a_prefix = o->b_prefix;
1981                b_prefix = o->a_prefix;
1982        } else {
1983                a_prefix = o->a_prefix;
1984                b_prefix = o->b_prefix;
1985        }
1986
1987        /* Never use a non-valid filename anywhere if at all possible */
1988        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1989        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1990
1991        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1992        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1993        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1994        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1995        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1996        if (lbl[0][0] == '/') {
1997                /* /dev/null */
1998                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1999                if (xfrm_msg)
2000                        strbuf_addstr(&header, xfrm_msg);
2001                must_show_header = 1;
2002        }
2003        else if (lbl[1][0] == '/') {
2004                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2005                if (xfrm_msg)
2006                        strbuf_addstr(&header, xfrm_msg);
2007                must_show_header = 1;
2008        }
2009        else {
2010                if (one->mode != two->mode) {
2011                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2012                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2013                        must_show_header = 1;
2014                }
2015                if (xfrm_msg)
2016                        strbuf_addstr(&header, xfrm_msg);
2017
2018                /*
2019                 * we do not run diff between different kind
2020                 * of objects.
2021                 */
2022                if ((one->mode ^ two->mode) & S_IFMT)
2023                        goto free_ab_and_return;
2024                if (complete_rewrite &&
2025                    (textconv_one || !diff_filespec_is_binary(one)) &&
2026                    (textconv_two || !diff_filespec_is_binary(two))) {
2027                        fprintf(o->file, "%s", header.buf);
2028                        strbuf_reset(&header);
2029                        emit_rewrite_diff(name_a, name_b, one, two,
2030                                                textconv_one, textconv_two, o);
2031                        o->found_changes = 1;
2032                        goto free_ab_and_return;
2033                }
2034        }
2035
2036        if (o->irreversible_delete && lbl[1][0] == '/') {
2037                fprintf(o->file, "%s", header.buf);
2038                strbuf_reset(&header);
2039                goto free_ab_and_return;
2040        } else if (!DIFF_OPT_TST(o, TEXT) &&
2041            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2042              (!textconv_two && diff_filespec_is_binary(two)) )) {
2043                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2044                        die("unable to read files to diff");
2045                /* Quite common confusing case */
2046                if (mf1.size == mf2.size &&
2047                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2048                        if (must_show_header)
2049                                fprintf(o->file, "%s", header.buf);
2050                        goto free_ab_and_return;
2051                }
2052                fprintf(o->file, "%s", header.buf);
2053                strbuf_reset(&header);
2054                if (DIFF_OPT_TST(o, BINARY))
2055                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2056                else
2057                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2058                                line_prefix, lbl[0], lbl[1]);
2059                o->found_changes = 1;
2060        } else {
2061                /* Crazy xdl interfaces.. */
2062                const char *diffopts = getenv("GIT_DIFF_OPTS");
2063                xpparam_t xpp;
2064                xdemitconf_t xecfg;
2065                struct emit_callback ecbdata;
2066                const struct userdiff_funcname *pe;
2067
2068                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2069                        fprintf(o->file, "%s", header.buf);
2070                        strbuf_reset(&header);
2071                }
2072
2073                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2074                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2075
2076                pe = diff_funcname_pattern(one);
2077                if (!pe)
2078                        pe = diff_funcname_pattern(two);
2079
2080                memset(&xpp, 0, sizeof(xpp));
2081                memset(&xecfg, 0, sizeof(xecfg));
2082                memset(&ecbdata, 0, sizeof(ecbdata));
2083                ecbdata.label_path = lbl;
2084                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2085                ecbdata.found_changesp = &o->found_changes;
2086                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2087                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2088                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2089                ecbdata.opt = o;
2090                ecbdata.header = header.len ? &header : NULL;
2091                xpp.flags = o->xdl_opts;
2092                xecfg.ctxlen = o->context;
2093                xecfg.interhunkctxlen = o->interhunkcontext;
2094                xecfg.flags = XDL_EMIT_FUNCNAMES;
2095                if (pe)
2096                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2097                if (!diffopts)
2098                        ;
2099                else if (!prefixcmp(diffopts, "--unified="))
2100                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2101                else if (!prefixcmp(diffopts, "-u"))
2102                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2103                if (o->word_diff) {
2104                        int i;
2105
2106                        ecbdata.diff_words =
2107                                xcalloc(1, sizeof(struct diff_words_data));
2108                        ecbdata.diff_words->type = o->word_diff;
2109                        ecbdata.diff_words->opt = o;
2110                        if (!o->word_regex)
2111                                o->word_regex = userdiff_word_regex(one);
2112                        if (!o->word_regex)
2113                                o->word_regex = userdiff_word_regex(two);
2114                        if (!o->word_regex)
2115                                o->word_regex = diff_word_regex_cfg;
2116                        if (o->word_regex) {
2117                                ecbdata.diff_words->word_regex = (regex_t *)
2118                                        xmalloc(sizeof(regex_t));
2119                                if (regcomp(ecbdata.diff_words->word_regex,
2120                                                o->word_regex,
2121                                                REG_EXTENDED | REG_NEWLINE))
2122                                        die ("Invalid regular expression: %s",
2123                                                        o->word_regex);
2124                        }
2125                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2126                                if (o->word_diff == diff_words_styles[i].type) {
2127                                        ecbdata.diff_words->style =
2128                                                &diff_words_styles[i];
2129                                        break;
2130                                }
2131                        }
2132                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2133                                struct diff_words_style *st = ecbdata.diff_words->style;
2134                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2135                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2136                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2137                        }
2138                }
2139                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2140                              &xpp, &xecfg);
2141                if (o->word_diff)
2142                        free_diff_words_data(&ecbdata);
2143                if (textconv_one)
2144                        free(mf1.ptr);
2145                if (textconv_two)
2146                        free(mf2.ptr);
2147                xdiff_clear_find_func(&xecfg);
2148        }
2149
2150 free_ab_and_return:
2151        strbuf_release(&header);
2152        diff_free_filespec_data(one);
2153        diff_free_filespec_data(two);
2154        free(a_one);
2155        free(b_two);
2156        return;
2157}
2158
2159static void builtin_diffstat(const char *name_a, const char *name_b,
2160                             struct diff_filespec *one,
2161                             struct diff_filespec *two,
2162                             struct diffstat_t *diffstat,
2163                             struct diff_options *o,
2164                             int complete_rewrite)
2165{
2166        mmfile_t mf1, mf2;
2167        struct diffstat_file *data;
2168
2169        data = diffstat_add(diffstat, name_a, name_b);
2170
2171        if (!one || !two) {
2172                data->is_unmerged = 1;
2173                return;
2174        }
2175
2176        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2177                data->is_binary = 1;
2178                data->added = diff_filespec_size(two);
2179                data->deleted = diff_filespec_size(one);
2180        }
2181
2182        else if (complete_rewrite) {
2183                diff_populate_filespec(one, 0);
2184                diff_populate_filespec(two, 0);
2185                data->deleted = count_lines(one->data, one->size);
2186                data->added = count_lines(two->data, two->size);
2187        }
2188
2189        else {
2190                /* Crazy xdl interfaces.. */
2191                xpparam_t xpp;
2192                xdemitconf_t xecfg;
2193
2194                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2195                        die("unable to read files to diff");
2196
2197                memset(&xpp, 0, sizeof(xpp));
2198                memset(&xecfg, 0, sizeof(xecfg));
2199                xpp.flags = o->xdl_opts;
2200                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2201                              &xpp, &xecfg);
2202        }
2203
2204        diff_free_filespec_data(one);
2205        diff_free_filespec_data(two);
2206}
2207
2208static void builtin_checkdiff(const char *name_a, const char *name_b,
2209                              const char *attr_path,
2210                              struct diff_filespec *one,
2211                              struct diff_filespec *two,
2212                              struct diff_options *o)
2213{
2214        mmfile_t mf1, mf2;
2215        struct checkdiff_t data;
2216
2217        if (!two)
2218                return;
2219
2220        memset(&data, 0, sizeof(data));
2221        data.filename = name_b ? name_b : name_a;
2222        data.lineno = 0;
2223        data.o = o;
2224        data.ws_rule = whitespace_rule(attr_path);
2225        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2226
2227        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2228                die("unable to read files to diff");
2229
2230        /*
2231         * All the other codepaths check both sides, but not checking
2232         * the "old" side here is deliberate.  We are checking the newly
2233         * introduced changes, and as long as the "new" side is text, we
2234         * can and should check what it introduces.
2235         */
2236        if (diff_filespec_is_binary(two))
2237                goto free_and_return;
2238        else {
2239                /* Crazy xdl interfaces.. */
2240                xpparam_t xpp;
2241                xdemitconf_t xecfg;
2242
2243                memset(&xpp, 0, sizeof(xpp));
2244                memset(&xecfg, 0, sizeof(xecfg));
2245                xecfg.ctxlen = 1; /* at least one context line */
2246                xpp.flags = 0;
2247                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2248                              &xpp, &xecfg);
2249
2250                if (data.ws_rule & WS_BLANK_AT_EOF) {
2251                        struct emit_callback ecbdata;
2252                        int blank_at_eof;
2253
2254                        ecbdata.ws_rule = data.ws_rule;
2255                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2256                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2257
2258                        if (blank_at_eof) {
2259                                static char *err;
2260                                if (!err)
2261                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2262                                fprintf(o->file, "%s:%d: %s.\n",
2263                                        data.filename, blank_at_eof, err);
2264                                data.status = 1; /* report errors */
2265                        }
2266                }
2267        }
2268 free_and_return:
2269        diff_free_filespec_data(one);
2270        diff_free_filespec_data(two);
2271        if (data.status)
2272                DIFF_OPT_SET(o, CHECK_FAILED);
2273}
2274
2275struct diff_filespec *alloc_filespec(const char *path)
2276{
2277        int namelen = strlen(path);
2278        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2279
2280        memset(spec, 0, sizeof(*spec));
2281        spec->path = (char *)(spec + 1);
2282        memcpy(spec->path, path, namelen+1);
2283        spec->count = 1;
2284        spec->is_binary = -1;
2285        return spec;
2286}
2287
2288void free_filespec(struct diff_filespec *spec)
2289{
2290        if (!--spec->count) {
2291                diff_free_filespec_data(spec);
2292                free(spec);
2293        }
2294}
2295
2296void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2297                   unsigned short mode)
2298{
2299        if (mode) {
2300                spec->mode = canon_mode(mode);
2301                hashcpy(spec->sha1, sha1);
2302                spec->sha1_valid = !is_null_sha1(sha1);
2303        }
2304}
2305
2306/*
2307 * Given a name and sha1 pair, if the index tells us the file in
2308 * the work tree has that object contents, return true, so that
2309 * prepare_temp_file() does not have to inflate and extract.
2310 */
2311static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2312{
2313        struct cache_entry *ce;
2314        struct stat st;
2315        int pos, len;
2316
2317        /*
2318         * We do not read the cache ourselves here, because the
2319         * benchmark with my previous version that always reads cache
2320         * shows that it makes things worse for diff-tree comparing
2321         * two linux-2.6 kernel trees in an already checked out work
2322         * tree.  This is because most diff-tree comparisons deal with
2323         * only a small number of files, while reading the cache is
2324         * expensive for a large project, and its cost outweighs the
2325         * savings we get by not inflating the object to a temporary
2326         * file.  Practically, this code only helps when we are used
2327         * by diff-cache --cached, which does read the cache before
2328         * calling us.
2329         */
2330        if (!active_cache)
2331                return 0;
2332
2333        /* We want to avoid the working directory if our caller
2334         * doesn't need the data in a normal file, this system
2335         * is rather slow with its stat/open/mmap/close syscalls,
2336         * and the object is contained in a pack file.  The pack
2337         * is probably already open and will be faster to obtain
2338         * the data through than the working directory.  Loose
2339         * objects however would tend to be slower as they need
2340         * to be individually opened and inflated.
2341         */
2342        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2343                return 0;
2344
2345        len = strlen(name);
2346        pos = cache_name_pos(name, len);
2347        if (pos < 0)
2348                return 0;
2349        ce = active_cache[pos];
2350
2351        /*
2352         * This is not the sha1 we are looking for, or
2353         * unreusable because it is not a regular file.
2354         */
2355        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2356                return 0;
2357
2358        /*
2359         * If ce is marked as "assume unchanged", there is no
2360         * guarantee that work tree matches what we are looking for.
2361         */
2362        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2363                return 0;
2364
2365        /*
2366         * If ce matches the file in the work tree, we can reuse it.
2367         */
2368        if (ce_uptodate(ce) ||
2369            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2370                return 1;
2371
2372        return 0;
2373}
2374
2375static int populate_from_stdin(struct diff_filespec *s)
2376{
2377        struct strbuf buf = STRBUF_INIT;
2378        size_t size = 0;
2379
2380        if (strbuf_read(&buf, 0, 0) < 0)
2381                return error("error while reading from stdin %s",
2382                                     strerror(errno));
2383
2384        s->should_munmap = 0;
2385        s->data = strbuf_detach(&buf, &size);
2386        s->size = size;
2387        s->should_free = 1;
2388        return 0;
2389}
2390
2391static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2392{
2393        int len;
2394        char *data = xmalloc(100), *dirty = "";
2395
2396        /* Are we looking at the work tree? */
2397        if (s->dirty_submodule)
2398                dirty = "-dirty";
2399
2400        len = snprintf(data, 100,
2401                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2402        s->data = data;
2403        s->size = len;
2404        s->should_free = 1;
2405        if (size_only) {
2406                s->data = NULL;
2407                free(data);
2408        }
2409        return 0;
2410}
2411
2412/*
2413 * While doing rename detection and pickaxe operation, we may need to
2414 * grab the data for the blob (or file) for our own in-core comparison.
2415 * diff_filespec has data and size fields for this purpose.
2416 */
2417int diff_populate_filespec(struct diff_filespec *s, int size_only)
2418{
2419        int err = 0;
2420        if (!DIFF_FILE_VALID(s))
2421                die("internal error: asking to populate invalid file.");
2422        if (S_ISDIR(s->mode))
2423                return -1;
2424
2425        if (s->data)
2426                return 0;
2427
2428        if (size_only && 0 < s->size)
2429                return 0;
2430
2431        if (S_ISGITLINK(s->mode))
2432                return diff_populate_gitlink(s, size_only);
2433
2434        if (!s->sha1_valid ||
2435            reuse_worktree_file(s->path, s->sha1, 0)) {
2436                struct strbuf buf = STRBUF_INIT;
2437                struct stat st;
2438                int fd;
2439
2440                if (!strcmp(s->path, "-"))
2441                        return populate_from_stdin(s);
2442
2443                if (lstat(s->path, &st) < 0) {
2444                        if (errno == ENOENT) {
2445                        err_empty:
2446                                err = -1;
2447                        empty:
2448                                s->data = (char *)"";
2449                                s->size = 0;
2450                                return err;
2451                        }
2452                }
2453                s->size = xsize_t(st.st_size);
2454                if (!s->size)
2455                        goto empty;
2456                if (S_ISLNK(st.st_mode)) {
2457                        struct strbuf sb = STRBUF_INIT;
2458
2459                        if (strbuf_readlink(&sb, s->path, s->size))
2460                                goto err_empty;
2461                        s->size = sb.len;
2462                        s->data = strbuf_detach(&sb, NULL);
2463                        s->should_free = 1;
2464                        return 0;
2465                }
2466                if (size_only)
2467                        return 0;
2468                fd = open(s->path, O_RDONLY);
2469                if (fd < 0)
2470                        goto err_empty;
2471                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2472                close(fd);
2473                s->should_munmap = 1;
2474
2475                /*
2476                 * Convert from working tree format to canonical git format
2477                 */
2478                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2479                        size_t size = 0;
2480                        munmap(s->data, s->size);
2481                        s->should_munmap = 0;
2482                        s->data = strbuf_detach(&buf, &size);
2483                        s->size = size;
2484                        s->should_free = 1;
2485                }
2486        }
2487        else {
2488                enum object_type type;
2489                if (size_only) {
2490                        type = sha1_object_info(s->sha1, &s->size);
2491                        if (type < 0)
2492                                die("unable to read %s", sha1_to_hex(s->sha1));
2493                } else {
2494                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2495                        if (!s->data)
2496                                die("unable to read %s", sha1_to_hex(s->sha1));
2497                        s->should_free = 1;
2498                }
2499        }
2500        return 0;
2501}
2502
2503void diff_free_filespec_blob(struct diff_filespec *s)
2504{
2505        if (s->should_free)
2506                free(s->data);
2507        else if (s->should_munmap)
2508                munmap(s->data, s->size);
2509
2510        if (s->should_free || s->should_munmap) {
2511                s->should_free = s->should_munmap = 0;
2512                s->data = NULL;
2513        }
2514}
2515
2516void diff_free_filespec_data(struct diff_filespec *s)
2517{
2518        diff_free_filespec_blob(s);
2519        free(s->cnt_data);
2520        s->cnt_data = NULL;
2521}
2522
2523static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2524                           void *blob,
2525                           unsigned long size,
2526                           const unsigned char *sha1,
2527                           int mode)
2528{
2529        int fd;
2530        struct strbuf buf = STRBUF_INIT;
2531        struct strbuf template = STRBUF_INIT;
2532        char *path_dup = xstrdup(path);
2533        const char *base = basename(path_dup);
2534
2535        /* Generate "XXXXXX_basename.ext" */
2536        strbuf_addstr(&template, "XXXXXX_");
2537        strbuf_addstr(&template, base);
2538
2539        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2540                        strlen(base) + 1);
2541        if (fd < 0)
2542                die_errno("unable to create temp-file");
2543        if (convert_to_working_tree(path,
2544                        (const char *)blob, (size_t)size, &buf)) {
2545                blob = buf.buf;
2546                size = buf.len;
2547        }
2548        if (write_in_full(fd, blob, size) != size)
2549                die_errno("unable to write temp-file");
2550        close(fd);
2551        temp->name = temp->tmp_path;
2552        strcpy(temp->hex, sha1_to_hex(sha1));
2553        temp->hex[40] = 0;
2554        sprintf(temp->mode, "%06o", mode);
2555        strbuf_release(&buf);
2556        strbuf_release(&template);
2557        free(path_dup);
2558}
2559
2560static struct diff_tempfile *prepare_temp_file(const char *name,
2561                struct diff_filespec *one)
2562{
2563        struct diff_tempfile *temp = claim_diff_tempfile();
2564
2565        if (!DIFF_FILE_VALID(one)) {
2566        not_a_valid_file:
2567                /* A '-' entry produces this for file-2, and
2568                 * a '+' entry produces this for file-1.
2569                 */
2570                temp->name = "/dev/null";
2571                strcpy(temp->hex, ".");
2572                strcpy(temp->mode, ".");
2573                return temp;
2574        }
2575
2576        if (!remove_tempfile_installed) {
2577                atexit(remove_tempfile);
2578                sigchain_push_common(remove_tempfile_on_signal);
2579                remove_tempfile_installed = 1;
2580        }
2581
2582        if (!one->sha1_valid ||
2583            reuse_worktree_file(name, one->sha1, 1)) {
2584                struct stat st;
2585                if (lstat(name, &st) < 0) {
2586                        if (errno == ENOENT)
2587                                goto not_a_valid_file;
2588                        die_errno("stat(%s)", name);
2589                }
2590                if (S_ISLNK(st.st_mode)) {
2591                        struct strbuf sb = STRBUF_INIT;
2592                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2593                                die_errno("readlink(%s)", name);
2594                        prep_temp_blob(name, temp, sb.buf, sb.len,
2595                                       (one->sha1_valid ?
2596                                        one->sha1 : null_sha1),
2597                                       (one->sha1_valid ?
2598                                        one->mode : S_IFLNK));
2599                        strbuf_release(&sb);
2600                }
2601                else {
2602                        /* we can borrow from the file in the work tree */
2603                        temp->name = name;
2604                        if (!one->sha1_valid)
2605                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2606                        else
2607                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2608                        /* Even though we may sometimes borrow the
2609                         * contents from the work tree, we always want
2610                         * one->mode.  mode is trustworthy even when
2611                         * !(one->sha1_valid), as long as
2612                         * DIFF_FILE_VALID(one).
2613                         */
2614                        sprintf(temp->mode, "%06o", one->mode);
2615                }
2616                return temp;
2617        }
2618        else {
2619                if (diff_populate_filespec(one, 0))
2620                        die("cannot read data blob for %s", one->path);
2621                prep_temp_blob(name, temp, one->data, one->size,
2622                               one->sha1, one->mode);
2623        }
2624        return temp;
2625}
2626
2627/* An external diff command takes:
2628 *
2629 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2630 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2631 *
2632 */
2633static void run_external_diff(const char *pgm,
2634                              const char *name,
2635                              const char *other,
2636                              struct diff_filespec *one,
2637                              struct diff_filespec *two,
2638                              const char *xfrm_msg,
2639                              int complete_rewrite)
2640{
2641        const char *spawn_arg[10];
2642        int retval;
2643        const char **arg = &spawn_arg[0];
2644
2645        if (one && two) {
2646                struct diff_tempfile *temp_one, *temp_two;
2647                const char *othername = (other ? other : name);
2648                temp_one = prepare_temp_file(name, one);
2649                temp_two = prepare_temp_file(othername, two);
2650                *arg++ = pgm;
2651                *arg++ = name;
2652                *arg++ = temp_one->name;
2653                *arg++ = temp_one->hex;
2654                *arg++ = temp_one->mode;
2655                *arg++ = temp_two->name;
2656                *arg++ = temp_two->hex;
2657                *arg++ = temp_two->mode;
2658                if (other) {
2659                        *arg++ = other;
2660                        *arg++ = xfrm_msg;
2661                }
2662        } else {
2663                *arg++ = pgm;
2664                *arg++ = name;
2665        }
2666        *arg = NULL;
2667        fflush(NULL);
2668        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2669        remove_tempfile();
2670        if (retval) {
2671                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2672                exit(1);
2673        }
2674}
2675
2676static int similarity_index(struct diff_filepair *p)
2677{
2678        return p->score * 100 / MAX_SCORE;
2679}
2680
2681static void fill_metainfo(struct strbuf *msg,
2682                          const char *name,
2683                          const char *other,
2684                          struct diff_filespec *one,
2685                          struct diff_filespec *two,
2686                          struct diff_options *o,
2687                          struct diff_filepair *p,
2688                          int *must_show_header,
2689                          int use_color)
2690{
2691        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2692        const char *reset = diff_get_color(use_color, DIFF_RESET);
2693        struct strbuf *msgbuf;
2694        char *line_prefix = "";
2695
2696        *must_show_header = 1;
2697        if (o->output_prefix) {
2698                msgbuf = o->output_prefix(o, o->output_prefix_data);
2699                line_prefix = msgbuf->buf;
2700        }
2701        strbuf_init(msg, PATH_MAX * 2 + 300);
2702        switch (p->status) {
2703        case DIFF_STATUS_COPIED:
2704                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2705                            line_prefix, set, similarity_index(p));
2706                strbuf_addf(msg, "%s\n%s%scopy from ",
2707                            reset,  line_prefix, set);
2708                quote_c_style(name, msg, NULL, 0);
2709                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2710                quote_c_style(other, msg, NULL, 0);
2711                strbuf_addf(msg, "%s\n", reset);
2712                break;
2713        case DIFF_STATUS_RENAMED:
2714                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2715                            line_prefix, set, similarity_index(p));
2716                strbuf_addf(msg, "%s\n%s%srename from ",
2717                            reset, line_prefix, set);
2718                quote_c_style(name, msg, NULL, 0);
2719                strbuf_addf(msg, "%s\n%s%srename to ",
2720                            reset, line_prefix, set);
2721                quote_c_style(other, msg, NULL, 0);
2722                strbuf_addf(msg, "%s\n", reset);
2723                break;
2724        case DIFF_STATUS_MODIFIED:
2725                if (p->score) {
2726                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2727                                    line_prefix,
2728                                    set, similarity_index(p), reset);
2729                        break;
2730                }
2731                /* fallthru */
2732        default:
2733                *must_show_header = 0;
2734        }
2735        if (one && two && hashcmp(one->sha1, two->sha1)) {
2736                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2737
2738                if (DIFF_OPT_TST(o, BINARY)) {
2739                        mmfile_t mf;
2740                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2741                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2742                                abbrev = 40;
2743                }
2744                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2745                            find_unique_abbrev(one->sha1, abbrev));
2746                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2747                if (one->mode == two->mode)
2748                        strbuf_addf(msg, " %06o", one->mode);
2749                strbuf_addf(msg, "%s\n", reset);
2750        }
2751}
2752
2753static void run_diff_cmd(const char *pgm,
2754                         const char *name,
2755                         const char *other,
2756                         const char *attr_path,
2757                         struct diff_filespec *one,
2758                         struct diff_filespec *two,
2759                         struct strbuf *msg,
2760                         struct diff_options *o,
2761                         struct diff_filepair *p)
2762{
2763        const char *xfrm_msg = NULL;
2764        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2765        int must_show_header = 0;
2766
2767        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2768                pgm = NULL;
2769        else {
2770                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2771                if (drv && drv->external)
2772                        pgm = drv->external;
2773        }
2774
2775        if (msg) {
2776                /*
2777                 * don't use colors when the header is intended for an
2778                 * external diff driver
2779                 */
2780                fill_metainfo(msg, name, other, one, two, o, p,
2781                              &must_show_header,
2782                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2783                xfrm_msg = msg->len ? msg->buf : NULL;
2784        }
2785
2786        if (pgm) {
2787                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2788                                  complete_rewrite);
2789                return;
2790        }
2791        if (one && two)
2792                builtin_diff(name, other ? other : name,
2793                             one, two, xfrm_msg, must_show_header,
2794                             o, complete_rewrite);
2795        else
2796                fprintf(o->file, "* Unmerged path %s\n", name);
2797}
2798
2799static void diff_fill_sha1_info(struct diff_filespec *one)
2800{
2801        if (DIFF_FILE_VALID(one)) {
2802                if (!one->sha1_valid) {
2803                        struct stat st;
2804                        if (!strcmp(one->path, "-")) {
2805                                hashcpy(one->sha1, null_sha1);
2806                                return;
2807                        }
2808                        if (lstat(one->path, &st) < 0)
2809                                die_errno("stat '%s'", one->path);
2810                        if (index_path(one->sha1, one->path, &st, 0))
2811                                die("cannot hash %s", one->path);
2812                }
2813        }
2814        else
2815                hashclr(one->sha1);
2816}
2817
2818static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2819{
2820        /* Strip the prefix but do not molest /dev/null and absolute paths */
2821        if (*namep && **namep != '/') {
2822                *namep += prefix_length;
2823                if (**namep == '/')
2824                        ++*namep;
2825        }
2826        if (*otherp && **otherp != '/') {
2827                *otherp += prefix_length;
2828                if (**otherp == '/')
2829                        ++*otherp;
2830        }
2831}
2832
2833static void run_diff(struct diff_filepair *p, struct diff_options *o)
2834{
2835        const char *pgm = external_diff();
2836        struct strbuf msg;
2837        struct diff_filespec *one = p->one;
2838        struct diff_filespec *two = p->two;
2839        const char *name;
2840        const char *other;
2841        const char *attr_path;
2842
2843        name  = p->one->path;
2844        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2845        attr_path = name;
2846        if (o->prefix_length)
2847                strip_prefix(o->prefix_length, &name, &other);
2848
2849        if (DIFF_PAIR_UNMERGED(p)) {
2850                run_diff_cmd(pgm, name, NULL, attr_path,
2851                             NULL, NULL, NULL, o, p);
2852                return;
2853        }
2854
2855        diff_fill_sha1_info(one);
2856        diff_fill_sha1_info(two);
2857
2858        if (!pgm &&
2859            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2860            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2861                /*
2862                 * a filepair that changes between file and symlink
2863                 * needs to be split into deletion and creation.
2864                 */
2865                struct diff_filespec *null = alloc_filespec(two->path);
2866                run_diff_cmd(NULL, name, other, attr_path,
2867                             one, null, &msg, o, p);
2868                free(null);
2869                strbuf_release(&msg);
2870
2871                null = alloc_filespec(one->path);
2872                run_diff_cmd(NULL, name, other, attr_path,
2873                             null, two, &msg, o, p);
2874                free(null);
2875        }
2876        else
2877                run_diff_cmd(pgm, name, other, attr_path,
2878                             one, two, &msg, o, p);
2879
2880        strbuf_release(&msg);
2881}
2882
2883static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2884                         struct diffstat_t *diffstat)
2885{
2886        const char *name;
2887        const char *other;
2888        int complete_rewrite = 0;
2889
2890        if (DIFF_PAIR_UNMERGED(p)) {
2891                /* unmerged */
2892                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2893                return;
2894        }
2895
2896        name = p->one->path;
2897        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2898
2899        if (o->prefix_length)
2900                strip_prefix(o->prefix_length, &name, &other);
2901
2902        diff_fill_sha1_info(p->one);
2903        diff_fill_sha1_info(p->two);
2904
2905        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2906                complete_rewrite = 1;
2907        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2908}
2909
2910static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2911{
2912        const char *name;
2913        const char *other;
2914        const char *attr_path;
2915
2916        if (DIFF_PAIR_UNMERGED(p)) {
2917                /* unmerged */
2918                return;
2919        }
2920
2921        name = p->one->path;
2922        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2923        attr_path = other ? other : name;
2924
2925        if (o->prefix_length)
2926                strip_prefix(o->prefix_length, &name, &other);
2927
2928        diff_fill_sha1_info(p->one);
2929        diff_fill_sha1_info(p->two);
2930
2931        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2932}
2933
2934void diff_setup(struct diff_options *options)
2935{
2936        memcpy(options, &default_diff_options, sizeof(*options));
2937
2938        options->file = stdout;
2939
2940        options->line_termination = '\n';
2941        options->break_opt = -1;
2942        options->rename_limit = -1;
2943        options->dirstat_permille = diff_dirstat_permille_default;
2944        options->context = 3;
2945
2946        options->change = diff_change;
2947        options->add_remove = diff_addremove;
2948        if (diff_use_color_default > 0)
2949                DIFF_OPT_SET(options, COLOR_DIFF);
2950        options->detect_rename = diff_detect_rename_default;
2951
2952        if (diff_no_prefix) {
2953                options->a_prefix = options->b_prefix = "";
2954        } else if (!diff_mnemonic_prefix) {
2955                options->a_prefix = "a/";
2956                options->b_prefix = "b/";
2957        }
2958}
2959
2960int diff_setup_done(struct diff_options *options)
2961{
2962        int count = 0;
2963
2964        if (options->output_format & DIFF_FORMAT_NAME)
2965                count++;
2966        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2967                count++;
2968        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2969                count++;
2970        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2971                count++;
2972        if (count > 1)
2973                die("--name-only, --name-status, --check and -s are mutually exclusive");
2974
2975        /*
2976         * Most of the time we can say "there are changes"
2977         * only by checking if there are changed paths, but
2978         * --ignore-whitespace* options force us to look
2979         * inside contents.
2980         */
2981
2982        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2983            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2984            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2985                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2986        else
2987                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2988
2989        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2990                options->detect_rename = DIFF_DETECT_COPY;
2991
2992        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2993                options->prefix = NULL;
2994        if (options->prefix)
2995                options->prefix_length = strlen(options->prefix);
2996        else
2997                options->prefix_length = 0;
2998
2999        if (options->output_format & (DIFF_FORMAT_NAME |
3000                                      DIFF_FORMAT_NAME_STATUS |
3001                                      DIFF_FORMAT_CHECKDIFF |
3002                                      DIFF_FORMAT_NO_OUTPUT))
3003                options->output_format &= ~(DIFF_FORMAT_RAW |
3004                                            DIFF_FORMAT_NUMSTAT |
3005                                            DIFF_FORMAT_DIFFSTAT |
3006                                            DIFF_FORMAT_SHORTSTAT |
3007                                            DIFF_FORMAT_DIRSTAT |
3008                                            DIFF_FORMAT_SUMMARY |
3009                                            DIFF_FORMAT_PATCH);
3010
3011        /*
3012         * These cases always need recursive; we do not drop caller-supplied
3013         * recursive bits for other formats here.
3014         */
3015        if (options->output_format & (DIFF_FORMAT_PATCH |
3016                                      DIFF_FORMAT_NUMSTAT |
3017                                      DIFF_FORMAT_DIFFSTAT |
3018                                      DIFF_FORMAT_SHORTSTAT |
3019                                      DIFF_FORMAT_DIRSTAT |
3020                                      DIFF_FORMAT_SUMMARY |
3021                                      DIFF_FORMAT_CHECKDIFF))
3022                DIFF_OPT_SET(options, RECURSIVE);
3023        /*
3024         * Also pickaxe would not work very well if you do not say recursive
3025         */
3026        if (options->pickaxe)
3027                DIFF_OPT_SET(options, RECURSIVE);
3028        /*
3029         * When patches are generated, submodules diffed against the work tree
3030         * must be checked for dirtiness too so it can be shown in the output
3031         */
3032        if (options->output_format & DIFF_FORMAT_PATCH)
3033                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3034
3035        if (options->detect_rename && options->rename_limit < 0)
3036                options->rename_limit = diff_rename_limit_default;
3037        if (options->setup & DIFF_SETUP_USE_CACHE) {
3038                if (!active_cache)
3039                        /* read-cache does not die even when it fails
3040                         * so it is safe for us to do this here.  Also
3041                         * it does not smudge active_cache or active_nr
3042                         * when it fails, so we do not have to worry about
3043                         * cleaning it up ourselves either.
3044                         */
3045                        read_cache();
3046        }
3047        if (options->abbrev <= 0 || 40 < options->abbrev)
3048                options->abbrev = 40; /* full */
3049
3050        /*
3051         * It does not make sense to show the first hit we happened
3052         * to have found.  It does not make sense not to return with
3053         * exit code in such a case either.
3054         */
3055        if (DIFF_OPT_TST(options, QUICK)) {
3056                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3057                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3058        }
3059
3060        return 0;
3061}
3062
3063static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3064{
3065        char c, *eq;
3066        int len;
3067
3068        if (*arg != '-')
3069                return 0;
3070        c = *++arg;
3071        if (!c)
3072                return 0;
3073        if (c == arg_short) {
3074                c = *++arg;
3075                if (!c)
3076                        return 1;
3077                if (val && isdigit(c)) {
3078                        char *end;
3079                        int n = strtoul(arg, &end, 10);
3080                        if (*end)
3081                                return 0;
3082                        *val = n;
3083                        return 1;
3084                }
3085                return 0;
3086        }
3087        if (c != '-')
3088                return 0;
3089        arg++;
3090        eq = strchr(arg, '=');
3091        if (eq)
3092                len = eq - arg;
3093        else
3094                len = strlen(arg);
3095        if (!len || strncmp(arg, arg_long, len))
3096                return 0;
3097        if (eq) {
3098                int n;
3099                char *end;
3100                if (!isdigit(*++eq))
3101                        return 0;
3102                n = strtoul(eq, &end, 10);
3103                if (*end)
3104                        return 0;
3105                *val = n;
3106        }
3107        return 1;
3108}
3109
3110static int diff_scoreopt_parse(const char *opt);
3111
3112static inline int short_opt(char opt, const char **argv,
3113                            const char **optarg)
3114{
3115        const char *arg = argv[0];
3116        if (arg[0] != '-' || arg[1] != opt)
3117                return 0;
3118        if (arg[2] != '\0') {
3119                *optarg = arg + 2;
3120                return 1;
3121        }
3122        if (!argv[1])
3123                die("Option '%c' requires a value", opt);
3124        *optarg = argv[1];
3125        return 2;
3126}
3127
3128int parse_long_opt(const char *opt, const char **argv,
3129                   const char **optarg)
3130{
3131        const char *arg = argv[0];
3132        if (arg[0] != '-' || arg[1] != '-')
3133                return 0;
3134        arg += strlen("--");
3135        if (prefixcmp(arg, opt))
3136                return 0;
3137        arg += strlen(opt);
3138        if (*arg == '=') { /* sticked form: --option=value */
3139                *optarg = arg + 1;
3140                return 1;
3141        }
3142        if (*arg != '\0')
3143                return 0;
3144        /* separate form: --option value */
3145        if (!argv[1])
3146                die("Option '--%s' requires a value", opt);
3147        *optarg = argv[1];
3148        return 2;
3149}
3150
3151static int stat_opt(struct diff_options *options, const char **av)
3152{
3153        const char *arg = av[0];
3154        char *end;
3155        int width = options->stat_width;
3156        int name_width = options->stat_name_width;
3157        int argcount = 1;
3158
3159        arg += strlen("--stat");
3160        end = (char *)arg;
3161
3162        switch (*arg) {
3163        case '-':
3164                if (!prefixcmp(arg, "-width")) {
3165                        arg += strlen("-width");
3166                        if (*arg == '=')
3167                                width = strtoul(arg + 1, &end, 10);
3168                        else if (!*arg && !av[1])
3169                                die("Option '--stat-width' requires a value");
3170                        else if (!*arg) {
3171                                width = strtoul(av[1], &end, 10);
3172                                argcount = 2;
3173                        }
3174                } else if (!prefixcmp(arg, "-name-width")) {
3175                        arg += strlen("-name-width");
3176                        if (*arg == '=')
3177                                name_width = strtoul(arg + 1, &end, 10);
3178                        else if (!*arg && !av[1])
3179                                die("Option '--stat-name-width' requires a value");
3180                        else if (!*arg) {
3181                                name_width = strtoul(av[1], &end, 10);
3182                                argcount = 2;
3183                        }
3184                }
3185                break;
3186        case '=':
3187                width = strtoul(arg+1, &end, 10);
3188                if (*end == ',')
3189                        name_width = strtoul(end+1, &end, 10);
3190        }
3191
3192        /* Important! This checks all the error cases! */
3193        if (*end)
3194                return 0;
3195        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3196        options->stat_name_width = name_width;
3197        options->stat_width = width;
3198        return argcount;
3199}
3200
3201static int parse_dirstat_opt(struct diff_options *options, const char *params)
3202{
3203        if (parse_dirstat_params(options, params))
3204                die("Failed to parse --dirstat/-X option parameter");
3205        /*
3206         * The caller knows a dirstat-related option is given from the command
3207         * line; allow it to say "return this_function();"
3208         */
3209        options->output_format |= DIFF_FORMAT_DIRSTAT;
3210        return 1;
3211}
3212
3213int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3214{
3215        const char *arg = av[0];
3216        const char *optarg;
3217        int argcount;
3218
3219        /* Output format options */
3220        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3221                options->output_format |= DIFF_FORMAT_PATCH;
3222        else if (opt_arg(arg, 'U', "unified", &options->context))
3223                options->output_format |= DIFF_FORMAT_PATCH;
3224        else if (!strcmp(arg, "--raw"))
3225                options->output_format |= DIFF_FORMAT_RAW;
3226        else if (!strcmp(arg, "--patch-with-raw"))
3227                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3228        else if (!strcmp(arg, "--numstat"))
3229                options->output_format |= DIFF_FORMAT_NUMSTAT;
3230        else if (!strcmp(arg, "--shortstat"))
3231                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3232        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3233                return parse_dirstat_opt(options, "");
3234        else if (!prefixcmp(arg, "-X"))
3235                return parse_dirstat_opt(options, arg + 2);
3236        else if (!prefixcmp(arg, "--dirstat="))
3237                return parse_dirstat_opt(options, arg + 10);
3238        else if (!strcmp(arg, "--cumulative"))
3239                return parse_dirstat_opt(options, "cumulative");
3240        else if (!strcmp(arg, "--dirstat-by-file"))
3241                return parse_dirstat_opt(options, "files");
3242        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3243                parse_dirstat_opt(options, "files");
3244                return parse_dirstat_opt(options, arg + 18);
3245        }
3246        else if (!strcmp(arg, "--check"))
3247                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3248        else if (!strcmp(arg, "--summary"))
3249                options->output_format |= DIFF_FORMAT_SUMMARY;
3250        else if (!strcmp(arg, "--patch-with-stat"))
3251                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3252        else if (!strcmp(arg, "--name-only"))
3253                options->output_format |= DIFF_FORMAT_NAME;
3254        else if (!strcmp(arg, "--name-status"))
3255                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3256        else if (!strcmp(arg, "-s"))
3257                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3258        else if (!prefixcmp(arg, "--stat"))
3259                /* --stat, --stat-width, or --stat-name-width */
3260                return stat_opt(options, av);
3261
3262        /* renames options */
3263        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3264                 !strcmp(arg, "--break-rewrites")) {
3265                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3266                        return error("invalid argument to -B: %s", arg+2);
3267        }
3268        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3269                 !strcmp(arg, "--find-renames")) {
3270                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3271                        return error("invalid argument to -M: %s", arg+2);
3272                options->detect_rename = DIFF_DETECT_RENAME;
3273        }
3274        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3275                options->irreversible_delete = 1;
3276        }
3277        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3278                 !strcmp(arg, "--find-copies")) {
3279                if (options->detect_rename == DIFF_DETECT_COPY)
3280                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3281                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3282                        return error("invalid argument to -C: %s", arg+2);
3283                options->detect_rename = DIFF_DETECT_COPY;
3284        }
3285        else if (!strcmp(arg, "--no-renames"))
3286                options->detect_rename = 0;
3287        else if (!strcmp(arg, "--relative"))
3288                DIFF_OPT_SET(options, RELATIVE_NAME);
3289        else if (!prefixcmp(arg, "--relative=")) {
3290                DIFF_OPT_SET(options, RELATIVE_NAME);
3291                options->prefix = arg + 11;
3292        }
3293
3294        /* xdiff options */
3295        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3296                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3297        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3298                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3299        else if (!strcmp(arg, "--ignore-space-at-eol"))
3300                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3301        else if (!strcmp(arg, "--patience"))
3302                DIFF_XDL_SET(options, PATIENCE_DIFF);
3303
3304        /* flags options */
3305        else if (!strcmp(arg, "--binary")) {
3306                options->output_format |= DIFF_FORMAT_PATCH;
3307                DIFF_OPT_SET(options, BINARY);
3308        }
3309        else if (!strcmp(arg, "--full-index"))
3310                DIFF_OPT_SET(options, FULL_INDEX);
3311        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3312                DIFF_OPT_SET(options, TEXT);
3313        else if (!strcmp(arg, "-R"))
3314                DIFF_OPT_SET(options, REVERSE_DIFF);
3315        else if (!strcmp(arg, "--find-copies-harder"))
3316                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3317        else if (!strcmp(arg, "--follow"))
3318                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3319        else if (!strcmp(arg, "--color"))
3320                DIFF_OPT_SET(options, COLOR_DIFF);
3321        else if (!prefixcmp(arg, "--color=")) {
3322                int value = git_config_colorbool(NULL, arg+8, -1);
3323                if (value == 0)
3324                        DIFF_OPT_CLR(options, COLOR_DIFF);
3325                else if (value > 0)
3326                        DIFF_OPT_SET(options, COLOR_DIFF);
3327                else
3328                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3329        }
3330        else if (!strcmp(arg, "--no-color"))
3331                DIFF_OPT_CLR(options, COLOR_DIFF);
3332        else if (!strcmp(arg, "--color-words")) {
3333                DIFF_OPT_SET(options, COLOR_DIFF);
3334                options->word_diff = DIFF_WORDS_COLOR;
3335        }
3336        else if (!prefixcmp(arg, "--color-words=")) {
3337                DIFF_OPT_SET(options, COLOR_DIFF);
3338                options->word_diff = DIFF_WORDS_COLOR;
3339                options->word_regex = arg + 14;
3340        }
3341        else if (!strcmp(arg, "--word-diff")) {
3342                if (options->word_diff == DIFF_WORDS_NONE)
3343                        options->word_diff = DIFF_WORDS_PLAIN;
3344        }
3345        else if (!prefixcmp(arg, "--word-diff=")) {
3346                const char *type = arg + 12;
3347                if (!strcmp(type, "plain"))
3348                        options->word_diff = DIFF_WORDS_PLAIN;
3349                else if (!strcmp(type, "color")) {
3350                        DIFF_OPT_SET(options, COLOR_DIFF);
3351                        options->word_diff = DIFF_WORDS_COLOR;
3352                }
3353                else if (!strcmp(type, "porcelain"))
3354                        options->word_diff = DIFF_WORDS_PORCELAIN;
3355                else if (!strcmp(type, "none"))
3356                        options->word_diff = DIFF_WORDS_NONE;
3357                else
3358                        die("bad --word-diff argument: %s", type);
3359        }
3360        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3361                if (options->word_diff == DIFF_WORDS_NONE)
3362                        options->word_diff = DIFF_WORDS_PLAIN;
3363                options->word_regex = optarg;
3364                return argcount;
3365        }
3366        else if (!strcmp(arg, "--exit-code"))
3367                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3368        else if (!strcmp(arg, "--quiet"))
3369                DIFF_OPT_SET(options, QUICK);
3370        else if (!strcmp(arg, "--ext-diff"))
3371                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3372        else if (!strcmp(arg, "--no-ext-diff"))
3373                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3374        else if (!strcmp(arg, "--textconv"))
3375                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3376        else if (!strcmp(arg, "--no-textconv"))
3377                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3378        else if (!strcmp(arg, "--ignore-submodules")) {
3379                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3380                handle_ignore_submodules_arg(options, "all");
3381        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3382                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3383                handle_ignore_submodules_arg(options, arg + 20);
3384        } else if (!strcmp(arg, "--submodule"))
3385                DIFF_OPT_SET(options, SUBMODULE_LOG);
3386        else if (!prefixcmp(arg, "--submodule=")) {
3387                if (!strcmp(arg + 12, "log"))
3388                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3389        }
3390
3391        /* misc options */
3392        else if (!strcmp(arg, "-z"))
3393                options->line_termination = 0;
3394        else if ((argcount = short_opt('l', av, &optarg))) {
3395                options->rename_limit = strtoul(optarg, NULL, 10);
3396                return argcount;
3397        }
3398        else if ((argcount = short_opt('S', av, &optarg))) {
3399                options->pickaxe = optarg;
3400                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3401                return argcount;
3402        } else if ((argcount = short_opt('G', av, &optarg))) {
3403                options->pickaxe = optarg;
3404                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3405                return argcount;
3406        }
3407        else if (!strcmp(arg, "--pickaxe-all"))
3408                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3409        else if (!strcmp(arg, "--pickaxe-regex"))
3410                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3411        else if ((argcount = short_opt('O', av, &optarg))) {
3412                options->orderfile = optarg;
3413                return argcount;
3414        }
3415        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3416                options->filter = optarg;
3417                return argcount;
3418        }
3419        else if (!strcmp(arg, "--abbrev"))
3420                options->abbrev = DEFAULT_ABBREV;
3421        else if (!prefixcmp(arg, "--abbrev=")) {
3422                options->abbrev = strtoul(arg + 9, NULL, 10);
3423                if (options->abbrev < MINIMUM_ABBREV)
3424                        options->abbrev = MINIMUM_ABBREV;
3425                else if (40 < options->abbrev)
3426                        options->abbrev = 40;
3427        }
3428        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3429                options->a_prefix = optarg;
3430                return argcount;
3431        }
3432        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3433                options->b_prefix = optarg;
3434                return argcount;
3435        }
3436        else if (!strcmp(arg, "--no-prefix"))
3437                options->a_prefix = options->b_prefix = "";
3438        else if (opt_arg(arg, '\0', "inter-hunk-context",
3439                         &options->interhunkcontext))
3440                ;
3441        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3442                options->file = fopen(optarg, "w");
3443                if (!options->file)
3444                        die_errno("Could not open '%s'", optarg);
3445                options->close_file = 1;
3446                return argcount;
3447        } else
3448                return 0;
3449        return 1;
3450}
3451
3452int parse_rename_score(const char **cp_p)
3453{
3454        unsigned long num, scale;
3455        int ch, dot;
3456        const char *cp = *cp_p;
3457
3458        num = 0;
3459        scale = 1;
3460        dot = 0;
3461        for (;;) {
3462                ch = *cp;
3463                if ( !dot && ch == '.' ) {
3464                        scale = 1;
3465                        dot = 1;
3466                } else if ( ch == '%' ) {
3467                        scale = dot ? scale*100 : 100;
3468                        cp++;   /* % is always at the end */
3469                        break;
3470                } else if ( ch >= '0' && ch <= '9' ) {
3471                        if ( scale < 100000 ) {
3472                                scale *= 10;
3473                                num = (num*10) + (ch-'0');
3474                        }
3475                } else {
3476                        break;
3477                }
3478                cp++;
3479        }
3480        *cp_p = cp;
3481
3482        /* user says num divided by scale and we say internally that
3483         * is MAX_SCORE * num / scale.
3484         */
3485        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3486}
3487
3488static int diff_scoreopt_parse(const char *opt)
3489{
3490        int opt1, opt2, cmd;
3491
3492        if (*opt++ != '-')
3493                return -1;
3494        cmd = *opt++;
3495        if (cmd == '-') {
3496                /* convert the long-form arguments into short-form versions */
3497                if (!prefixcmp(opt, "break-rewrites")) {
3498                        opt += strlen("break-rewrites");
3499                        if (*opt == 0 || *opt++ == '=')
3500                                cmd = 'B';
3501                } else if (!prefixcmp(opt, "find-copies")) {
3502                        opt += strlen("find-copies");
3503                        if (*opt == 0 || *opt++ == '=')
3504                                cmd = 'C';
3505                } else if (!prefixcmp(opt, "find-renames")) {
3506                        opt += strlen("find-renames");
3507                        if (*opt == 0 || *opt++ == '=')
3508                                cmd = 'M';
3509                }
3510        }
3511        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3512                return -1; /* that is not a -M, -C nor -B option */
3513
3514        opt1 = parse_rename_score(&opt);
3515        if (cmd != 'B')
3516                opt2 = 0;
3517        else {
3518                if (*opt == 0)
3519                        opt2 = 0;
3520                else if (*opt != '/')
3521                        return -1; /* we expect -B80/99 or -B80 */
3522                else {
3523                        opt++;
3524                        opt2 = parse_rename_score(&opt);
3525                }
3526        }
3527        if (*opt != 0)
3528                return -1;
3529        return opt1 | (opt2 << 16);
3530}
3531
3532struct diff_queue_struct diff_queued_diff;
3533
3534void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3535{
3536        if (queue->alloc <= queue->nr) {
3537                queue->alloc = alloc_nr(queue->alloc);
3538                queue->queue = xrealloc(queue->queue,
3539                                        sizeof(dp) * queue->alloc);
3540        }
3541        queue->queue[queue->nr++] = dp;
3542}
3543
3544struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3545                                 struct diff_filespec *one,
3546                                 struct diff_filespec *two)
3547{
3548        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3549        dp->one = one;
3550        dp->two = two;
3551        if (queue)
3552                diff_q(queue, dp);
3553        return dp;
3554}
3555
3556void diff_free_filepair(struct diff_filepair *p)
3557{
3558        free_filespec(p->one);
3559        free_filespec(p->two);
3560        free(p);
3561}
3562
3563/* This is different from find_unique_abbrev() in that
3564 * it stuffs the result with dots for alignment.
3565 */
3566const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3567{
3568        int abblen;
3569        const char *abbrev;
3570        if (len == 40)
3571                return sha1_to_hex(sha1);
3572
3573        abbrev = find_unique_abbrev(sha1, len);
3574        abblen = strlen(abbrev);
3575        if (abblen < 37) {
3576                static char hex[41];
3577                if (len < abblen && abblen <= len + 2)
3578                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3579                else
3580                        sprintf(hex, "%s...", abbrev);
3581                return hex;
3582        }
3583        return sha1_to_hex(sha1);
3584}
3585
3586static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3587{
3588        int line_termination = opt->line_termination;
3589        int inter_name_termination = line_termination ? '\t' : '\0';
3590        if (opt->output_prefix) {
3591                struct strbuf *msg = NULL;
3592                msg = opt->output_prefix(opt, opt->output_prefix_data);
3593                fprintf(opt->file, "%s", msg->buf);
3594        }
3595
3596        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3597                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3598                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3599                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3600        }
3601        if (p->score) {
3602                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3603                        inter_name_termination);
3604        } else {
3605                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3606        }
3607
3608        if (p->status == DIFF_STATUS_COPIED ||
3609            p->status == DIFF_STATUS_RENAMED) {
3610                const char *name_a, *name_b;
3611                name_a = p->one->path;
3612                name_b = p->two->path;
3613                strip_prefix(opt->prefix_length, &name_a, &name_b);
3614                write_name_quoted(name_a, opt->file, inter_name_termination);
3615                write_name_quoted(name_b, opt->file, line_termination);
3616        } else {
3617                const char *name_a, *name_b;
3618                name_a = p->one->mode ? p->one->path : p->two->path;
3619                name_b = NULL;
3620                strip_prefix(opt->prefix_length, &name_a, &name_b);
3621                write_name_quoted(name_a, opt->file, line_termination);
3622        }
3623}
3624
3625int diff_unmodified_pair(struct diff_filepair *p)
3626{
3627        /* This function is written stricter than necessary to support
3628         * the currently implemented transformers, but the idea is to
3629         * let transformers to produce diff_filepairs any way they want,
3630         * and filter and clean them up here before producing the output.
3631         */
3632        struct diff_filespec *one = p->one, *two = p->two;
3633
3634        if (DIFF_PAIR_UNMERGED(p))
3635                return 0; /* unmerged is interesting */
3636
3637        /* deletion, addition, mode or type change
3638         * and rename are all interesting.
3639         */
3640        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3641            DIFF_PAIR_MODE_CHANGED(p) ||
3642            strcmp(one->path, two->path))
3643                return 0;
3644
3645        /* both are valid and point at the same path.  that is, we are
3646         * dealing with a change.
3647         */
3648        if (one->sha1_valid && two->sha1_valid &&
3649            !hashcmp(one->sha1, two->sha1) &&
3650            !one->dirty_submodule && !two->dirty_submodule)
3651                return 1; /* no change */
3652        if (!one->sha1_valid && !two->sha1_valid)
3653                return 1; /* both look at the same file on the filesystem. */
3654        return 0;
3655}
3656
3657static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3658{
3659        if (diff_unmodified_pair(p))
3660                return;
3661
3662        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3663            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3664                return; /* no tree diffs in patch format */
3665
3666        run_diff(p, o);
3667}
3668
3669static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3670                            struct diffstat_t *diffstat)
3671{
3672        if (diff_unmodified_pair(p))
3673                return;
3674
3675        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3676            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3677                return; /* no useful stat for tree diffs */
3678
3679        run_diffstat(p, o, diffstat);
3680}
3681
3682static void diff_flush_checkdiff(struct diff_filepair *p,
3683                struct diff_options *o)
3684{
3685        if (diff_unmodified_pair(p))
3686                return;
3687
3688        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3689            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3690                return; /* nothing to check in tree diffs */
3691
3692        run_checkdiff(p, o);
3693}
3694
3695int diff_queue_is_empty(void)
3696{
3697        struct diff_queue_struct *q = &diff_queued_diff;
3698        int i;
3699        for (i = 0; i < q->nr; i++)
3700                if (!diff_unmodified_pair(q->queue[i]))
3701                        return 0;
3702        return 1;
3703}
3704
3705#if DIFF_DEBUG
3706void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3707{
3708        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3709                x, one ? one : "",
3710                s->path,
3711                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3712                s->mode,
3713                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3714        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3715                x, one ? one : "",
3716                s->size, s->xfrm_flags);
3717}
3718
3719void diff_debug_filepair(const struct diff_filepair *p, int i)
3720{
3721        diff_debug_filespec(p->one, i, "one");
3722        diff_debug_filespec(p->two, i, "two");
3723        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3724                p->score, p->status ? p->status : '?',
3725                p->one->rename_used, p->broken_pair);
3726}
3727
3728void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3729{
3730        int i;
3731        if (msg)
3732                fprintf(stderr, "%s\n", msg);
3733        fprintf(stderr, "q->nr = %d\n", q->nr);
3734        for (i = 0; i < q->nr; i++) {
3735                struct diff_filepair *p = q->queue[i];
3736                diff_debug_filepair(p, i);
3737        }
3738}
3739#endif
3740
3741static void diff_resolve_rename_copy(void)
3742{
3743        int i;
3744        struct diff_filepair *p;
3745        struct diff_queue_struct *q = &diff_queued_diff;
3746
3747        diff_debug_queue("resolve-rename-copy", q);
3748
3749        for (i = 0; i < q->nr; i++) {
3750                p = q->queue[i];
3751                p->status = 0; /* undecided */
3752                if (DIFF_PAIR_UNMERGED(p))
3753                        p->status = DIFF_STATUS_UNMERGED;
3754                else if (!DIFF_FILE_VALID(p->one))
3755                        p->status = DIFF_STATUS_ADDED;
3756                else if (!DIFF_FILE_VALID(p->two))
3757                        p->status = DIFF_STATUS_DELETED;
3758                else if (DIFF_PAIR_TYPE_CHANGED(p))
3759                        p->status = DIFF_STATUS_TYPE_CHANGED;
3760
3761                /* from this point on, we are dealing with a pair
3762                 * whose both sides are valid and of the same type, i.e.
3763                 * either in-place edit or rename/copy edit.
3764                 */
3765                else if (DIFF_PAIR_RENAME(p)) {
3766                        /*
3767                         * A rename might have re-connected a broken
3768                         * pair up, causing the pathnames to be the
3769                         * same again. If so, that's not a rename at
3770                         * all, just a modification..
3771                         *
3772                         * Otherwise, see if this source was used for
3773                         * multiple renames, in which case we decrement
3774                         * the count, and call it a copy.
3775                         */
3776                        if (!strcmp(p->one->path, p->two->path))
3777                                p->status = DIFF_STATUS_MODIFIED;
3778                        else if (--p->one->rename_used > 0)
3779                                p->status = DIFF_STATUS_COPIED;
3780                        else
3781                                p->status = DIFF_STATUS_RENAMED;
3782                }
3783                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3784                         p->one->mode != p->two->mode ||
3785                         p->one->dirty_submodule ||
3786                         p->two->dirty_submodule ||
3787                         is_null_sha1(p->one->sha1))
3788                        p->status = DIFF_STATUS_MODIFIED;
3789                else {
3790                        /* This is a "no-change" entry and should not
3791                         * happen anymore, but prepare for broken callers.
3792                         */
3793                        error("feeding unmodified %s to diffcore",
3794                              p->one->path);
3795                        p->status = DIFF_STATUS_UNKNOWN;
3796                }
3797        }
3798        diff_debug_queue("resolve-rename-copy done", q);
3799}
3800
3801static int check_pair_status(struct diff_filepair *p)
3802{
3803        switch (p->status) {
3804        case DIFF_STATUS_UNKNOWN:
3805                return 0;
3806        case 0:
3807                die("internal error in diff-resolve-rename-copy");
3808        default:
3809                return 1;
3810        }
3811}
3812
3813static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3814{
3815        int fmt = opt->output_format;
3816
3817        if (fmt & DIFF_FORMAT_CHECKDIFF)
3818                diff_flush_checkdiff(p, opt);
3819        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3820                diff_flush_raw(p, opt);
3821        else if (fmt & DIFF_FORMAT_NAME) {
3822                const char *name_a, *name_b;
3823                name_a = p->two->path;
3824                name_b = NULL;
3825                strip_prefix(opt->prefix_length, &name_a, &name_b);
3826                write_name_quoted(name_a, opt->file, opt->line_termination);
3827        }
3828}
3829
3830static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3831{
3832        if (fs->mode)
3833                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3834        else
3835                fprintf(file, " %s ", newdelete);
3836        write_name_quoted(fs->path, file, '\n');
3837}
3838
3839
3840static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3841                const char *line_prefix)
3842{
3843        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3844                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3845                        p->two->mode, show_name ? ' ' : '\n');
3846                if (show_name) {
3847                        write_name_quoted(p->two->path, file, '\n');
3848                }
3849        }
3850}
3851
3852static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3853                        const char *line_prefix)
3854{
3855        char *names = pprint_rename(p->one->path, p->two->path);
3856
3857        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3858        free(names);
3859        show_mode_change(file, p, 0, line_prefix);
3860}
3861
3862static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3863{
3864        FILE *file = opt->file;
3865        char *line_prefix = "";
3866
3867        if (opt->output_prefix) {
3868                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3869                line_prefix = buf->buf;
3870        }
3871
3872        switch(p->status) {
3873        case DIFF_STATUS_DELETED:
3874                fputs(line_prefix, file);
3875                show_file_mode_name(file, "delete", p->one);
3876                break;
3877        case DIFF_STATUS_ADDED:
3878                fputs(line_prefix, file);
3879                show_file_mode_name(file, "create", p->two);
3880                break;
3881        case DIFF_STATUS_COPIED:
3882                fputs(line_prefix, file);
3883                show_rename_copy(file, "copy", p, line_prefix);
3884                break;
3885        case DIFF_STATUS_RENAMED:
3886                fputs(line_prefix, file);
3887                show_rename_copy(file, "rename", p, line_prefix);
3888                break;
3889        default:
3890                if (p->score) {
3891                        fprintf(file, "%s rewrite ", line_prefix);
3892                        write_name_quoted(p->two->path, file, ' ');
3893                        fprintf(file, "(%d%%)\n", similarity_index(p));
3894                }
3895                show_mode_change(file, p, !p->score, line_prefix);
3896                break;
3897        }
3898}
3899
3900struct patch_id_t {
3901        git_SHA_CTX *ctx;
3902        int patchlen;
3903};
3904
3905static int remove_space(char *line, int len)
3906{
3907        int i;
3908        char *dst = line;
3909        unsigned char c;
3910
3911        for (i = 0; i < len; i++)
3912                if (!isspace((c = line[i])))
3913                        *dst++ = c;
3914
3915        return dst - line;
3916}
3917
3918static void patch_id_consume(void *priv, char *line, unsigned long len)
3919{
3920        struct patch_id_t *data = priv;
3921        int new_len;
3922
3923        /* Ignore line numbers when computing the SHA1 of the patch */
3924        if (!prefixcmp(line, "@@ -"))
3925                return;
3926
3927        new_len = remove_space(line, len);
3928
3929        git_SHA1_Update(data->ctx, line, new_len);
3930        data->patchlen += new_len;
3931}
3932
3933/* returns 0 upon success, and writes result into sha1 */
3934static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3935{
3936        struct diff_queue_struct *q = &diff_queued_diff;
3937        int i;
3938        git_SHA_CTX ctx;
3939        struct patch_id_t data;
3940        char buffer[PATH_MAX * 4 + 20];
3941
3942        git_SHA1_Init(&ctx);
3943        memset(&data, 0, sizeof(struct patch_id_t));
3944        data.ctx = &ctx;
3945
3946        for (i = 0; i < q->nr; i++) {
3947                xpparam_t xpp;
3948                xdemitconf_t xecfg;
3949                mmfile_t mf1, mf2;
3950                struct diff_filepair *p = q->queue[i];
3951                int len1, len2;
3952
3953                memset(&xpp, 0, sizeof(xpp));
3954                memset(&xecfg, 0, sizeof(xecfg));
3955                if (p->status == 0)
3956                        return error("internal diff status error");
3957                if (p->status == DIFF_STATUS_UNKNOWN)
3958                        continue;
3959                if (diff_unmodified_pair(p))
3960                        continue;
3961                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3962                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3963                        continue;
3964                if (DIFF_PAIR_UNMERGED(p))
3965                        continue;
3966
3967                diff_fill_sha1_info(p->one);
3968                diff_fill_sha1_info(p->two);
3969                if (fill_mmfile(&mf1, p->one) < 0 ||
3970                                fill_mmfile(&mf2, p->two) < 0)
3971                        return error("unable to read files to diff");
3972
3973                len1 = remove_space(p->one->path, strlen(p->one->path));
3974                len2 = remove_space(p->two->path, strlen(p->two->path));
3975                if (p->one->mode == 0)
3976                        len1 = snprintf(buffer, sizeof(buffer),
3977                                        "diff--gita/%.*sb/%.*s"
3978                                        "newfilemode%06o"
3979                                        "---/dev/null"
3980                                        "+++b/%.*s",
3981                                        len1, p->one->path,
3982                                        len2, p->two->path,
3983                                        p->two->mode,
3984                                        len2, p->two->path);
3985                else if (p->two->mode == 0)
3986                        len1 = snprintf(buffer, sizeof(buffer),
3987                                        "diff--gita/%.*sb/%.*s"
3988                                        "deletedfilemode%06o"
3989                                        "---a/%.*s"
3990                                        "+++/dev/null",
3991                                        len1, p->one->path,
3992                                        len2, p->two->path,
3993                                        p->one->mode,
3994                                        len1, p->one->path);
3995                else
3996                        len1 = snprintf(buffer, sizeof(buffer),
3997                                        "diff--gita/%.*sb/%.*s"
3998                                        "---a/%.*s"
3999                                        "+++b/%.*s",
4000                                        len1, p->one->path,
4001                                        len2, p->two->path,
4002                                        len1, p->one->path,
4003                                        len2, p->two->path);
4004                git_SHA1_Update(&ctx, buffer, len1);
4005
4006                if (diff_filespec_is_binary(p->one) ||
4007                    diff_filespec_is_binary(p->two)) {
4008                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4009                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4010                        continue;
4011                }
4012
4013                xpp.flags = 0;
4014                xecfg.ctxlen = 3;
4015                xecfg.flags = 0;
4016                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4017                              &xpp, &xecfg);
4018        }
4019
4020        git_SHA1_Final(sha1, &ctx);
4021        return 0;
4022}
4023
4024int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4025{
4026        struct diff_queue_struct *q = &diff_queued_diff;
4027        int i;
4028        int result = diff_get_patch_id(options, sha1);
4029
4030        for (i = 0; i < q->nr; i++)
4031                diff_free_filepair(q->queue[i]);
4032
4033        free(q->queue);
4034        DIFF_QUEUE_CLEAR(q);
4035
4036        return result;
4037}
4038
4039static int is_summary_empty(const struct diff_queue_struct *q)
4040{
4041        int i;
4042
4043        for (i = 0; i < q->nr; i++) {
4044                const struct diff_filepair *p = q->queue[i];
4045
4046                switch (p->status) {
4047                case DIFF_STATUS_DELETED:
4048                case DIFF_STATUS_ADDED:
4049                case DIFF_STATUS_COPIED:
4050                case DIFF_STATUS_RENAMED:
4051                        return 0;
4052                default:
4053                        if (p->score)
4054                                return 0;
4055                        if (p->one->mode && p->two->mode &&
4056                            p->one->mode != p->two->mode)
4057                                return 0;
4058                        break;
4059                }
4060        }
4061        return 1;
4062}
4063
4064static const char rename_limit_warning[] =
4065"inexact rename detection was skipped due to too many files.";
4066
4067static const char degrade_cc_to_c_warning[] =
4068"only found copies from modified paths due to too many files.";
4069
4070static const char rename_limit_advice[] =
4071"you may want to set your %s variable to at least "
4072"%d and retry the command.";
4073
4074void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4075{
4076        if (degraded_cc)
4077                warning(degrade_cc_to_c_warning);
4078        else if (needed)
4079                warning(rename_limit_warning);
4080        else
4081                return;
4082        if (0 < needed && needed < 32767)
4083                warning(rename_limit_advice, varname, needed);
4084}
4085
4086void diff_flush(struct diff_options *options)
4087{
4088        struct diff_queue_struct *q = &diff_queued_diff;
4089        int i, output_format = options->output_format;
4090        int separator = 0;
4091
4092        /*
4093         * Order: raw, stat, summary, patch
4094         * or:    name/name-status/checkdiff (other bits clear)
4095         */
4096        if (!q->nr)
4097                goto free_queue;
4098
4099        if (output_format & (DIFF_FORMAT_RAW |
4100                             DIFF_FORMAT_NAME |
4101                             DIFF_FORMAT_NAME_STATUS |
4102                             DIFF_FORMAT_CHECKDIFF)) {
4103                for (i = 0; i < q->nr; i++) {
4104                        struct diff_filepair *p = q->queue[i];
4105                        if (check_pair_status(p))
4106                                flush_one_pair(p, options);
4107                }
4108                separator++;
4109        }
4110
4111        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
4112                struct diffstat_t diffstat;
4113
4114                memset(&diffstat, 0, sizeof(struct diffstat_t));
4115                for (i = 0; i < q->nr; i++) {
4116                        struct diff_filepair *p = q->queue[i];
4117                        if (check_pair_status(p))
4118                                diff_flush_stat(p, options, &diffstat);
4119                }
4120                if (output_format & DIFF_FORMAT_NUMSTAT)
4121                        show_numstat(&diffstat, options);
4122                if (output_format & DIFF_FORMAT_DIFFSTAT)
4123                        show_stats(&diffstat, options);
4124                if (output_format & DIFF_FORMAT_SHORTSTAT)
4125                        show_shortstats(&diffstat, options);
4126                free_diffstat_info(&diffstat);
4127                separator++;
4128        }
4129        if (output_format & DIFF_FORMAT_DIRSTAT)
4130                show_dirstat(options);
4131
4132        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4133                for (i = 0; i < q->nr; i++) {
4134                        diff_summary(options, q->queue[i]);
4135                }
4136                separator++;
4137        }
4138
4139        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4140            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4141            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4142                /*
4143                 * run diff_flush_patch for the exit status. setting
4144                 * options->file to /dev/null should be safe, becaue we
4145                 * aren't supposed to produce any output anyway.
4146                 */
4147                if (options->close_file)
4148                        fclose(options->file);
4149                options->file = fopen("/dev/null", "w");
4150                if (!options->file)
4151                        die_errno("Could not open /dev/null");
4152                options->close_file = 1;
4153                for (i = 0; i < q->nr; i++) {
4154                        struct diff_filepair *p = q->queue[i];
4155                        if (check_pair_status(p))
4156                                diff_flush_patch(p, options);
4157                        if (options->found_changes)
4158                                break;
4159                }
4160        }
4161
4162        if (output_format & DIFF_FORMAT_PATCH) {
4163                if (separator) {
4164                        putc(options->line_termination, options->file);
4165                        if (options->stat_sep) {
4166                                /* attach patch instead of inline */
4167                                fputs(options->stat_sep, options->file);
4168                        }
4169                }
4170
4171                for (i = 0; i < q->nr; i++) {
4172                        struct diff_filepair *p = q->queue[i];
4173                        if (check_pair_status(p))
4174                                diff_flush_patch(p, options);
4175                }
4176        }
4177
4178        if (output_format & DIFF_FORMAT_CALLBACK)
4179                options->format_callback(q, options, options->format_callback_data);
4180
4181        for (i = 0; i < q->nr; i++)
4182                diff_free_filepair(q->queue[i]);
4183free_queue:
4184        free(q->queue);
4185        DIFF_QUEUE_CLEAR(q);
4186        if (options->close_file)
4187                fclose(options->file);
4188
4189        /*
4190         * Report the content-level differences with HAS_CHANGES;
4191         * diff_addremove/diff_change does not set the bit when
4192         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4193         */
4194        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4195                if (options->found_changes)
4196                        DIFF_OPT_SET(options, HAS_CHANGES);
4197                else
4198                        DIFF_OPT_CLR(options, HAS_CHANGES);
4199        }
4200}
4201
4202static void diffcore_apply_filter(const char *filter)
4203{
4204        int i;
4205        struct diff_queue_struct *q = &diff_queued_diff;
4206        struct diff_queue_struct outq;
4207        DIFF_QUEUE_CLEAR(&outq);
4208
4209        if (!filter)
4210                return;
4211
4212        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4213                int found;
4214                for (i = found = 0; !found && i < q->nr; i++) {
4215                        struct diff_filepair *p = q->queue[i];
4216                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4217                             ((p->score &&
4218                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4219                              (!p->score &&
4220                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4221                            ((p->status != DIFF_STATUS_MODIFIED) &&
4222                             strchr(filter, p->status)))
4223                                found++;
4224                }
4225                if (found)
4226                        return;
4227
4228                /* otherwise we will clear the whole queue
4229                 * by copying the empty outq at the end of this
4230                 * function, but first clear the current entries
4231                 * in the queue.
4232                 */
4233                for (i = 0; i < q->nr; i++)
4234                        diff_free_filepair(q->queue[i]);
4235        }
4236        else {
4237                /* Only the matching ones */
4238                for (i = 0; i < q->nr; i++) {
4239                        struct diff_filepair *p = q->queue[i];
4240
4241                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4242                             ((p->score &&
4243                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4244                              (!p->score &&
4245                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4246                            ((p->status != DIFF_STATUS_MODIFIED) &&
4247                             strchr(filter, p->status)))
4248                                diff_q(&outq, p);
4249                        else
4250                                diff_free_filepair(p);
4251                }
4252        }
4253        free(q->queue);
4254        *q = outq;
4255}
4256
4257/* Check whether two filespecs with the same mode and size are identical */
4258static int diff_filespec_is_identical(struct diff_filespec *one,
4259                                      struct diff_filespec *two)
4260{
4261        if (S_ISGITLINK(one->mode))
4262                return 0;
4263        if (diff_populate_filespec(one, 0))
4264                return 0;
4265        if (diff_populate_filespec(two, 0))
4266                return 0;
4267        return !memcmp(one->data, two->data, one->size);
4268}
4269
4270static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4271{
4272        int i;
4273        struct diff_queue_struct *q = &diff_queued_diff;
4274        struct diff_queue_struct outq;
4275        DIFF_QUEUE_CLEAR(&outq);
4276
4277        for (i = 0; i < q->nr; i++) {
4278                struct diff_filepair *p = q->queue[i];
4279
4280                /*
4281                 * 1. Entries that come from stat info dirtiness
4282                 *    always have both sides (iow, not create/delete),
4283                 *    one side of the object name is unknown, with
4284                 *    the same mode and size.  Keep the ones that
4285                 *    do not match these criteria.  They have real
4286                 *    differences.
4287                 *
4288                 * 2. At this point, the file is known to be modified,
4289                 *    with the same mode and size, and the object
4290                 *    name of one side is unknown.  Need to inspect
4291                 *    the identical contents.
4292                 */
4293                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4294                    !DIFF_FILE_VALID(p->two) ||
4295                    (p->one->sha1_valid && p->two->sha1_valid) ||
4296                    (p->one->mode != p->two->mode) ||
4297                    diff_populate_filespec(p->one, 1) ||
4298                    diff_populate_filespec(p->two, 1) ||
4299                    (p->one->size != p->two->size) ||
4300                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4301                        diff_q(&outq, p);
4302                else {
4303                        /*
4304                         * The caller can subtract 1 from skip_stat_unmatch
4305                         * to determine how many paths were dirty only
4306                         * due to stat info mismatch.
4307                         */
4308                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4309                                diffopt->skip_stat_unmatch++;
4310                        diff_free_filepair(p);
4311                }
4312        }
4313        free(q->queue);
4314        *q = outq;
4315}
4316
4317static int diffnamecmp(const void *a_, const void *b_)
4318{
4319        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4320        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4321        const char *name_a, *name_b;
4322
4323        name_a = a->one ? a->one->path : a->two->path;
4324        name_b = b->one ? b->one->path : b->two->path;
4325        return strcmp(name_a, name_b);
4326}
4327
4328void diffcore_fix_diff_index(struct diff_options *options)
4329{
4330        struct diff_queue_struct *q = &diff_queued_diff;
4331        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4332}
4333
4334void diffcore_std(struct diff_options *options)
4335{
4336        if (options->skip_stat_unmatch)
4337                diffcore_skip_stat_unmatch(options);
4338        if (!options->found_follow) {
4339                /* See try_to_follow_renames() in tree-diff.c */
4340                if (options->break_opt != -1)
4341                        diffcore_break(options->break_opt);
4342                if (options->detect_rename)
4343                        diffcore_rename(options);
4344                if (options->break_opt != -1)
4345                        diffcore_merge_broken();
4346        }
4347        if (options->pickaxe)
4348                diffcore_pickaxe(options);
4349        if (options->orderfile)
4350                diffcore_order(options->orderfile);
4351        if (!options->found_follow)
4352                /* See try_to_follow_renames() in tree-diff.c */
4353                diff_resolve_rename_copy();
4354        diffcore_apply_filter(options->filter);
4355
4356        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4357                DIFF_OPT_SET(options, HAS_CHANGES);
4358        else
4359                DIFF_OPT_CLR(options, HAS_CHANGES);
4360
4361        options->found_follow = 0;
4362}
4363
4364int diff_result_code(struct diff_options *opt, int status)
4365{
4366        int result = 0;
4367
4368        diff_warn_rename_limit("diff.renamelimit",
4369                               opt->needed_rename_limit,
4370                               opt->degraded_cc_to_c);
4371        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4372            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4373                return status;
4374        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4375            DIFF_OPT_TST(opt, HAS_CHANGES))
4376                result |= 01;
4377        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4378            DIFF_OPT_TST(opt, CHECK_FAILED))
4379                result |= 02;
4380        return result;
4381}
4382
4383/*
4384 * Shall changes to this submodule be ignored?
4385 *
4386 * Submodule changes can be configured to be ignored separately for each path,
4387 * but that configuration can be overridden from the command line.
4388 */
4389static int is_submodule_ignored(const char *path, struct diff_options *options)
4390{
4391        int ignored = 0;
4392        unsigned orig_flags = options->flags;
4393        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4394                set_diffopt_flags_from_submodule_config(options, path);
4395        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4396                ignored = 1;
4397        options->flags = orig_flags;
4398        return ignored;
4399}
4400
4401void diff_addremove(struct diff_options *options,
4402                    int addremove, unsigned mode,
4403                    const unsigned char *sha1,
4404                    const char *concatpath, unsigned dirty_submodule)
4405{
4406        struct diff_filespec *one, *two;
4407
4408        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4409                return;
4410
4411        /* This may look odd, but it is a preparation for
4412         * feeding "there are unchanged files which should
4413         * not produce diffs, but when you are doing copy
4414         * detection you would need them, so here they are"
4415         * entries to the diff-core.  They will be prefixed
4416         * with something like '=' or '*' (I haven't decided
4417         * which but should not make any difference).
4418         * Feeding the same new and old to diff_change()
4419         * also has the same effect.
4420         * Before the final output happens, they are pruned after
4421         * merged into rename/copy pairs as appropriate.
4422         */
4423        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4424                addremove = (addremove == '+' ? '-' :
4425                             addremove == '-' ? '+' : addremove);
4426
4427        if (options->prefix &&
4428            strncmp(concatpath, options->prefix, options->prefix_length))
4429                return;
4430
4431        one = alloc_filespec(concatpath);
4432        two = alloc_filespec(concatpath);
4433
4434        if (addremove != '+')
4435                fill_filespec(one, sha1, mode);
4436        if (addremove != '-') {
4437                fill_filespec(two, sha1, mode);
4438                two->dirty_submodule = dirty_submodule;
4439        }
4440
4441        diff_queue(&diff_queued_diff, one, two);
4442        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4443                DIFF_OPT_SET(options, HAS_CHANGES);
4444}
4445
4446void diff_change(struct diff_options *options,
4447                 unsigned old_mode, unsigned new_mode,
4448                 const unsigned char *old_sha1,
4449                 const unsigned char *new_sha1,
4450                 const char *concatpath,
4451                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4452{
4453        struct diff_filespec *one, *two;
4454
4455        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4456            is_submodule_ignored(concatpath, options))
4457                return;
4458
4459        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4460                unsigned tmp;
4461                const unsigned char *tmp_c;
4462                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4463                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4464                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4465                        new_dirty_submodule = tmp;
4466        }
4467
4468        if (options->prefix &&
4469            strncmp(concatpath, options->prefix, options->prefix_length))
4470                return;
4471
4472        one = alloc_filespec(concatpath);
4473        two = alloc_filespec(concatpath);
4474        fill_filespec(one, old_sha1, old_mode);
4475        fill_filespec(two, new_sha1, new_mode);
4476        one->dirty_submodule = old_dirty_submodule;
4477        two->dirty_submodule = new_dirty_submodule;
4478
4479        diff_queue(&diff_queued_diff, one, two);
4480        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4481                DIFF_OPT_SET(options, HAS_CHANGES);
4482}
4483
4484void diff_unmerge(struct diff_options *options,
4485                  const char *path,
4486                  unsigned mode, const unsigned char *sha1)
4487{
4488        struct diff_filespec *one, *two;
4489
4490        if (options->prefix &&
4491            strncmp(path, options->prefix, options->prefix_length))
4492                return;
4493
4494        one = alloc_filespec(path);
4495        two = alloc_filespec(path);
4496        fill_filespec(one, sha1, mode);
4497        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4498}
4499
4500static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4501                size_t *outsize)
4502{
4503        struct diff_tempfile *temp;
4504        const char *argv[3];
4505        const char **arg = argv;
4506        struct child_process child;
4507        struct strbuf buf = STRBUF_INIT;
4508        int err = 0;
4509
4510        temp = prepare_temp_file(spec->path, spec);
4511        *arg++ = pgm;
4512        *arg++ = temp->name;
4513        *arg = NULL;
4514
4515        memset(&child, 0, sizeof(child));
4516        child.use_shell = 1;
4517        child.argv = argv;
4518        child.out = -1;
4519        if (start_command(&child)) {
4520                remove_tempfile();
4521                return NULL;
4522        }
4523
4524        if (strbuf_read(&buf, child.out, 0) < 0)
4525                err = error("error reading from textconv command '%s'", pgm);
4526        close(child.out);
4527
4528        if (finish_command(&child) || err) {
4529                strbuf_release(&buf);
4530                remove_tempfile();
4531                return NULL;
4532        }
4533        remove_tempfile();
4534
4535        return strbuf_detach(&buf, outsize);
4536}
4537
4538size_t fill_textconv(struct userdiff_driver *driver,
4539                     struct diff_filespec *df,
4540                     char **outbuf)
4541{
4542        size_t size;
4543
4544        if (!driver || !driver->textconv) {
4545                if (!DIFF_FILE_VALID(df)) {
4546                        *outbuf = "";
4547                        return 0;
4548                }
4549                if (diff_populate_filespec(df, 0))
4550                        die("unable to read files to diff");
4551                *outbuf = df->data;
4552                return df->size;
4553        }
4554
4555        if (driver->textconv_cache && df->sha1_valid) {
4556                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4557                                          &size);
4558                if (*outbuf)
4559                        return size;
4560        }
4561
4562        *outbuf = run_textconv(driver->textconv, df, &size);
4563        if (!*outbuf)
4564                die("unable to read files to diff");
4565
4566        if (driver->textconv_cache && df->sha1_valid) {
4567                /* ignore errors, as we might be in a readonly repository */
4568                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4569                                size);
4570                /*
4571                 * we could save up changes and flush them all at the end,
4572                 * but we would need an extra call after all diffing is done.
4573                 * Since generating a cache entry is the slow path anyway,
4574                 * this extra overhead probably isn't a big deal.
4575                 */
4576                notes_cache_write(driver->textconv_cache);
4577        }
4578
4579        return size;
4580}