diff.con commit gitweb: Fix handling of whitespace in generated links (67976c6)
   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 = 200;
  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 struct diff_options default_diff_options;
  35
  36static char diff_colors[][COLOR_MAXLEN] = {
  37        GIT_COLOR_RESET,
  38        GIT_COLOR_NORMAL,       /* PLAIN */
  39        GIT_COLOR_BOLD,         /* METAINFO */
  40        GIT_COLOR_CYAN,         /* FRAGINFO */
  41        GIT_COLOR_RED,          /* OLD */
  42        GIT_COLOR_GREEN,        /* NEW */
  43        GIT_COLOR_YELLOW,       /* COMMIT */
  44        GIT_COLOR_BG_RED,       /* WHITESPACE */
  45        GIT_COLOR_NORMAL,       /* FUNCINFO */
  46};
  47
  48static int parse_diff_color_slot(const char *var, int ofs)
  49{
  50        if (!strcasecmp(var+ofs, "plain"))
  51                return DIFF_PLAIN;
  52        if (!strcasecmp(var+ofs, "meta"))
  53                return DIFF_METAINFO;
  54        if (!strcasecmp(var+ofs, "frag"))
  55                return DIFF_FRAGINFO;
  56        if (!strcasecmp(var+ofs, "old"))
  57                return DIFF_FILE_OLD;
  58        if (!strcasecmp(var+ofs, "new"))
  59                return DIFF_FILE_NEW;
  60        if (!strcasecmp(var+ofs, "commit"))
  61                return DIFF_COMMIT;
  62        if (!strcasecmp(var+ofs, "whitespace"))
  63                return DIFF_WHITESPACE;
  64        if (!strcasecmp(var+ofs, "func"))
  65                return DIFF_FUNCINFO;
  66        return -1;
  67}
  68
  69static int git_config_rename(const char *var, const char *value)
  70{
  71        if (!value)
  72                return DIFF_DETECT_RENAME;
  73        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  74                return  DIFF_DETECT_COPY;
  75        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  76}
  77
  78/*
  79 * These are to give UI layer defaults.
  80 * The core-level commands such as git-diff-files should
  81 * never be affected by the setting of diff.renames
  82 * the user happens to have in the configuration file.
  83 */
  84int git_diff_ui_config(const char *var, const char *value, void *cb)
  85{
  86        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  87                diff_use_color_default = git_config_colorbool(var, value, -1);
  88                return 0;
  89        }
  90        if (!strcmp(var, "diff.renames")) {
  91                diff_detect_rename_default = git_config_rename(var, value);
  92                return 0;
  93        }
  94        if (!strcmp(var, "diff.autorefreshindex")) {
  95                diff_auto_refresh_index = git_config_bool(var, value);
  96                return 0;
  97        }
  98        if (!strcmp(var, "diff.mnemonicprefix")) {
  99                diff_mnemonic_prefix = git_config_bool(var, value);
 100                return 0;
 101        }
 102        if (!strcmp(var, "diff.noprefix")) {
 103                diff_no_prefix = git_config_bool(var, value);
 104                return 0;
 105        }
 106        if (!strcmp(var, "diff.external"))
 107                return git_config_string(&external_diff_cmd_cfg, var, value);
 108        if (!strcmp(var, "diff.wordregex"))
 109                return git_config_string(&diff_word_regex_cfg, var, value);
 110
 111        if (!strcmp(var, "diff.ignoresubmodules"))
 112                handle_ignore_submodules_arg(&default_diff_options, value);
 113
 114        return git_diff_basic_config(var, value, cb);
 115}
 116
 117int git_diff_basic_config(const char *var, const char *value, void *cb)
 118{
 119        if (!strcmp(var, "diff.renamelimit")) {
 120                diff_rename_limit_default = git_config_int(var, value);
 121                return 0;
 122        }
 123
 124        switch (userdiff_config(var, value)) {
 125                case 0: break;
 126                case -1: return -1;
 127                default: return 0;
 128        }
 129
 130        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 131                int slot = parse_diff_color_slot(var, 11);
 132                if (slot < 0)
 133                        return 0;
 134                if (!value)
 135                        return config_error_nonbool(var);
 136                color_parse(value, var, diff_colors[slot]);
 137                return 0;
 138        }
 139
 140        /* like GNU diff's --suppress-blank-empty option  */
 141        if (!strcmp(var, "diff.suppressblankempty") ||
 142                        /* for backwards compatibility */
 143                        !strcmp(var, "diff.suppress-blank-empty")) {
 144                diff_suppress_blank_empty = git_config_bool(var, value);
 145                return 0;
 146        }
 147
 148        if (!prefixcmp(var, "submodule."))
 149                return parse_submodule_config_option(var, value);
 150
 151        return git_color_default_config(var, value, cb);
 152}
 153
 154static char *quote_two(const char *one, const char *two)
 155{
 156        int need_one = quote_c_style(one, NULL, NULL, 1);
 157        int need_two = quote_c_style(two, NULL, NULL, 1);
 158        struct strbuf res = STRBUF_INIT;
 159
 160        if (need_one + need_two) {
 161                strbuf_addch(&res, '"');
 162                quote_c_style(one, &res, NULL, 1);
 163                quote_c_style(two, &res, NULL, 1);
 164                strbuf_addch(&res, '"');
 165        } else {
 166                strbuf_addstr(&res, one);
 167                strbuf_addstr(&res, two);
 168        }
 169        return strbuf_detach(&res, NULL);
 170}
 171
 172static const char *external_diff(void)
 173{
 174        static const char *external_diff_cmd = NULL;
 175        static int done_preparing = 0;
 176
 177        if (done_preparing)
 178                return external_diff_cmd;
 179        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 180        if (!external_diff_cmd)
 181                external_diff_cmd = external_diff_cmd_cfg;
 182        done_preparing = 1;
 183        return external_diff_cmd;
 184}
 185
 186static struct diff_tempfile {
 187        const char *name; /* filename external diff should read from */
 188        char hex[41];
 189        char mode[10];
 190        char tmp_path[PATH_MAX];
 191} diff_temp[2];
 192
 193typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 194
 195struct emit_callback {
 196        int color_diff;
 197        unsigned ws_rule;
 198        int blank_at_eof_in_preimage;
 199        int blank_at_eof_in_postimage;
 200        int lno_in_preimage;
 201        int lno_in_postimage;
 202        sane_truncate_fn truncate;
 203        const char **label_path;
 204        struct diff_words_data *diff_words;
 205        struct diff_options *opt;
 206        int *found_changesp;
 207        struct strbuf *header;
 208};
 209
 210static int count_lines(const char *data, int size)
 211{
 212        int count, ch, completely_empty = 1, nl_just_seen = 0;
 213        count = 0;
 214        while (0 < size--) {
 215                ch = *data++;
 216                if (ch == '\n') {
 217                        count++;
 218                        nl_just_seen = 1;
 219                        completely_empty = 0;
 220                }
 221                else {
 222                        nl_just_seen = 0;
 223                        completely_empty = 0;
 224                }
 225        }
 226        if (completely_empty)
 227                return 0;
 228        if (!nl_just_seen)
 229                count++; /* no trailing newline */
 230        return count;
 231}
 232
 233static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 234{
 235        if (!DIFF_FILE_VALID(one)) {
 236                mf->ptr = (char *)""; /* does not matter */
 237                mf->size = 0;
 238                return 0;
 239        }
 240        else if (diff_populate_filespec(one, 0))
 241                return -1;
 242
 243        mf->ptr = one->data;
 244        mf->size = one->size;
 245        return 0;
 246}
 247
 248static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 249{
 250        char *ptr = mf->ptr;
 251        long size = mf->size;
 252        int cnt = 0;
 253
 254        if (!size)
 255                return cnt;
 256        ptr += size - 1; /* pointing at the very end */
 257        if (*ptr != '\n')
 258                ; /* incomplete line */
 259        else
 260                ptr--; /* skip the last LF */
 261        while (mf->ptr < ptr) {
 262                char *prev_eol;
 263                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 264                        if (*prev_eol == '\n')
 265                                break;
 266                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 267                        break;
 268                cnt++;
 269                ptr = prev_eol - 1;
 270        }
 271        return cnt;
 272}
 273
 274static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 275                               struct emit_callback *ecbdata)
 276{
 277        int l1, l2, at;
 278        unsigned ws_rule = ecbdata->ws_rule;
 279        l1 = count_trailing_blank(mf1, ws_rule);
 280        l2 = count_trailing_blank(mf2, ws_rule);
 281        if (l2 <= l1) {
 282                ecbdata->blank_at_eof_in_preimage = 0;
 283                ecbdata->blank_at_eof_in_postimage = 0;
 284                return;
 285        }
 286        at = count_lines(mf1->ptr, mf1->size);
 287        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 288
 289        at = count_lines(mf2->ptr, mf2->size);
 290        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 291}
 292
 293static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 294                        int first, const char *line, int len)
 295{
 296        int has_trailing_newline, has_trailing_carriage_return;
 297        int nofirst;
 298        FILE *file = o->file;
 299
 300        if (o->output_prefix) {
 301                struct strbuf *msg = NULL;
 302                msg = o->output_prefix(o, o->output_prefix_data);
 303                assert(msg);
 304                fwrite(msg->buf, msg->len, 1, file);
 305        }
 306
 307        if (len == 0) {
 308                has_trailing_newline = (first == '\n');
 309                has_trailing_carriage_return = (!has_trailing_newline &&
 310                                                (first == '\r'));
 311                nofirst = has_trailing_newline || has_trailing_carriage_return;
 312        } else {
 313                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 314                if (has_trailing_newline)
 315                        len--;
 316                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 317                if (has_trailing_carriage_return)
 318                        len--;
 319                nofirst = 0;
 320        }
 321
 322        if (len || !nofirst) {
 323                fputs(set, file);
 324                if (!nofirst)
 325                        fputc(first, file);
 326                fwrite(line, len, 1, file);
 327                fputs(reset, file);
 328        }
 329        if (has_trailing_carriage_return)
 330                fputc('\r', file);
 331        if (has_trailing_newline)
 332                fputc('\n', file);
 333}
 334
 335static void emit_line(struct diff_options *o, const char *set, const char *reset,
 336                      const char *line, int len)
 337{
 338        emit_line_0(o, set, reset, line[0], line+1, len-1);
 339}
 340
 341static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 342{
 343        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 344              ecbdata->blank_at_eof_in_preimage &&
 345              ecbdata->blank_at_eof_in_postimage &&
 346              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 347              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 348                return 0;
 349        return ws_blank_line(line, len, ecbdata->ws_rule);
 350}
 351
 352static void emit_add_line(const char *reset,
 353                          struct emit_callback *ecbdata,
 354                          const char *line, int len)
 355{
 356        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 357        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 358
 359        if (!*ws)
 360                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 361        else if (new_blank_line_at_eof(ecbdata, line, len))
 362                /* Blank line at EOF - paint '+' as well */
 363                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 364        else {
 365                /* Emit just the prefix, then the rest. */
 366                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 367                ws_check_emit(line, len, ecbdata->ws_rule,
 368                              ecbdata->opt->file, set, reset, ws);
 369        }
 370}
 371
 372static void emit_hunk_header(struct emit_callback *ecbdata,
 373                             const char *line, int len)
 374{
 375        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 376        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 377        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 378        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 379        static const char atat[2] = { '@', '@' };
 380        const char *cp, *ep;
 381        struct strbuf msgbuf = STRBUF_INIT;
 382        int org_len = len;
 383        int i = 1;
 384
 385        /*
 386         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 387         * it always is at least 10 bytes long.
 388         */
 389        if (len < 10 ||
 390            memcmp(line, atat, 2) ||
 391            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 392                emit_line(ecbdata->opt, plain, reset, line, len);
 393                return;
 394        }
 395        ep += 2; /* skip over @@ */
 396
 397        /* The hunk header in fraginfo color */
 398        strbuf_add(&msgbuf, frag, strlen(frag));
 399        strbuf_add(&msgbuf, line, ep - line);
 400        strbuf_add(&msgbuf, reset, strlen(reset));
 401
 402        /*
 403         * trailing "\r\n"
 404         */
 405        for ( ; i < 3; i++)
 406                if (line[len - i] == '\r' || line[len - i] == '\n')
 407                        len--;
 408
 409        /* blank before the func header */
 410        for (cp = ep; ep - line < len; ep++)
 411                if (*ep != ' ' && *ep != '\t')
 412                        break;
 413        if (ep != cp) {
 414                strbuf_add(&msgbuf, plain, strlen(plain));
 415                strbuf_add(&msgbuf, cp, ep - cp);
 416                strbuf_add(&msgbuf, reset, strlen(reset));
 417        }
 418
 419        if (ep < line + len) {
 420                strbuf_add(&msgbuf, func, strlen(func));
 421                strbuf_add(&msgbuf, ep, line + len - ep);
 422                strbuf_add(&msgbuf, reset, strlen(reset));
 423        }
 424
 425        strbuf_add(&msgbuf, line + len, org_len - len);
 426        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 427        strbuf_release(&msgbuf);
 428}
 429
 430static struct diff_tempfile *claim_diff_tempfile(void) {
 431        int i;
 432        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 433                if (!diff_temp[i].name)
 434                        return diff_temp + i;
 435        die("BUG: diff is failing to clean up its tempfiles");
 436}
 437
 438static int remove_tempfile_installed;
 439
 440static void remove_tempfile(void)
 441{
 442        int i;
 443        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 444                if (diff_temp[i].name == diff_temp[i].tmp_path)
 445                        unlink_or_warn(diff_temp[i].name);
 446                diff_temp[i].name = NULL;
 447        }
 448}
 449
 450static void remove_tempfile_on_signal(int signo)
 451{
 452        remove_tempfile();
 453        sigchain_pop(signo);
 454        raise(signo);
 455}
 456
 457static void print_line_count(FILE *file, int count)
 458{
 459        switch (count) {
 460        case 0:
 461                fprintf(file, "0,0");
 462                break;
 463        case 1:
 464                fprintf(file, "1");
 465                break;
 466        default:
 467                fprintf(file, "1,%d", count);
 468                break;
 469        }
 470}
 471
 472static void emit_rewrite_lines(struct emit_callback *ecb,
 473                               int prefix, const char *data, int size)
 474{
 475        const char *endp = NULL;
 476        static const char *nneof = " No newline at end of file\n";
 477        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 478        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 479
 480        while (0 < size) {
 481                int len;
 482
 483                endp = memchr(data, '\n', size);
 484                len = endp ? (endp - data + 1) : size;
 485                if (prefix != '+') {
 486                        ecb->lno_in_preimage++;
 487                        emit_line_0(ecb->opt, old, reset, '-',
 488                                    data, len);
 489                } else {
 490                        ecb->lno_in_postimage++;
 491                        emit_add_line(reset, ecb, data, len);
 492                }
 493                size -= len;
 494                data += len;
 495        }
 496        if (!endp) {
 497                const char *plain = diff_get_color(ecb->color_diff,
 498                                                   DIFF_PLAIN);
 499                emit_line_0(ecb->opt, plain, reset, '\\',
 500                            nneof, strlen(nneof));
 501        }
 502}
 503
 504static void emit_rewrite_diff(const char *name_a,
 505                              const char *name_b,
 506                              struct diff_filespec *one,
 507                              struct diff_filespec *two,
 508                              struct userdiff_driver *textconv_one,
 509                              struct userdiff_driver *textconv_two,
 510                              struct diff_options *o)
 511{
 512        int lc_a, lc_b;
 513        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 514        const char *name_a_tab, *name_b_tab;
 515        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 516        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 517        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 518        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 519        const char *a_prefix, *b_prefix;
 520        char *data_one, *data_two;
 521        size_t size_one, size_two;
 522        struct emit_callback ecbdata;
 523        char *line_prefix = "";
 524        struct strbuf *msgbuf;
 525
 526        if (o && o->output_prefix) {
 527                msgbuf = o->output_prefix(o, o->output_prefix_data);
 528                line_prefix = msgbuf->buf;
 529        }
 530
 531        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 532                a_prefix = o->b_prefix;
 533                b_prefix = o->a_prefix;
 534        } else {
 535                a_prefix = o->a_prefix;
 536                b_prefix = o->b_prefix;
 537        }
 538
 539        name_a += (*name_a == '/');
 540        name_b += (*name_b == '/');
 541        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 542        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 543
 544        strbuf_reset(&a_name);
 545        strbuf_reset(&b_name);
 546        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 547        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 548
 549        size_one = fill_textconv(textconv_one, one, &data_one);
 550        size_two = fill_textconv(textconv_two, two, &data_two);
 551
 552        memset(&ecbdata, 0, sizeof(ecbdata));
 553        ecbdata.color_diff = color_diff;
 554        ecbdata.found_changesp = &o->found_changes;
 555        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 556        ecbdata.opt = o;
 557        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 558                mmfile_t mf1, mf2;
 559                mf1.ptr = (char *)data_one;
 560                mf2.ptr = (char *)data_two;
 561                mf1.size = size_one;
 562                mf2.size = size_two;
 563                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 564        }
 565        ecbdata.lno_in_preimage = 1;
 566        ecbdata.lno_in_postimage = 1;
 567
 568        lc_a = count_lines(data_one, size_one);
 569        lc_b = count_lines(data_two, size_two);
 570        fprintf(o->file,
 571                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 572                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 573                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 574                line_prefix, fraginfo);
 575        print_line_count(o->file, lc_a);
 576        fprintf(o->file, " +");
 577        print_line_count(o->file, lc_b);
 578        fprintf(o->file, " @@%s\n", reset);
 579        if (lc_a)
 580                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 581        if (lc_b)
 582                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 583        if (textconv_one)
 584                free((char *)data_one);
 585        if (textconv_two)
 586                free((char *)data_two);
 587}
 588
 589struct diff_words_buffer {
 590        mmfile_t text;
 591        long alloc;
 592        struct diff_words_orig {
 593                const char *begin, *end;
 594        } *orig;
 595        int orig_nr, orig_alloc;
 596};
 597
 598static void diff_words_append(char *line, unsigned long len,
 599                struct diff_words_buffer *buffer)
 600{
 601        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 602        line++;
 603        len--;
 604        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 605        buffer->text.size += len;
 606        buffer->text.ptr[buffer->text.size] = '\0';
 607}
 608
 609struct diff_words_style_elem
 610{
 611        const char *prefix;
 612        const char *suffix;
 613        const char *color; /* NULL; filled in by the setup code if
 614                            * color is enabled */
 615};
 616
 617struct diff_words_style
 618{
 619        enum diff_words_type type;
 620        struct diff_words_style_elem new, old, ctx;
 621        const char *newline;
 622};
 623
 624struct diff_words_style diff_words_styles[] = {
 625        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 626        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 627        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 628};
 629
 630struct diff_words_data {
 631        struct diff_words_buffer minus, plus;
 632        const char *current_plus;
 633        int last_minus;
 634        struct diff_options *opt;
 635        regex_t *word_regex;
 636        enum diff_words_type type;
 637        struct diff_words_style *style;
 638};
 639
 640static int fn_out_diff_words_write_helper(FILE *fp,
 641                                          struct diff_words_style_elem *st_el,
 642                                          const char *newline,
 643                                          size_t count, const char *buf,
 644                                          const char *line_prefix)
 645{
 646        int print = 0;
 647
 648        while (count) {
 649                char *p = memchr(buf, '\n', count);
 650                if (print)
 651                        fputs(line_prefix, fp);
 652                if (p != buf) {
 653                        if (st_el->color && fputs(st_el->color, fp) < 0)
 654                                return -1;
 655                        if (fputs(st_el->prefix, fp) < 0 ||
 656                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 657                            fputs(st_el->suffix, fp) < 0)
 658                                return -1;
 659                        if (st_el->color && *st_el->color
 660                            && fputs(GIT_COLOR_RESET, fp) < 0)
 661                                return -1;
 662                }
 663                if (!p)
 664                        return 0;
 665                if (fputs(newline, fp) < 0)
 666                        return -1;
 667                count -= p + 1 - buf;
 668                buf = p + 1;
 669                print = 1;
 670        }
 671        return 0;
 672}
 673
 674/*
 675 * '--color-words' algorithm can be described as:
 676 *
 677 *   1. collect a the minus/plus lines of a diff hunk, divided into
 678 *      minus-lines and plus-lines;
 679 *
 680 *   2. break both minus-lines and plus-lines into words and
 681 *      place them into two mmfile_t with one word for each line;
 682 *
 683 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 684 *
 685 * And for the common parts of the both file, we output the plus side text.
 686 * diff_words->current_plus is used to trace the current position of the plus file
 687 * which printed. diff_words->last_minus is used to trace the last minus word
 688 * printed.
 689 *
 690 * For '--graph' to work with '--color-words', we need to output the graph prefix
 691 * on each line of color words output. Generally, there are two conditions on
 692 * which we should output the prefix.
 693 *
 694 *   1. diff_words->last_minus == 0 &&
 695 *      diff_words->current_plus == diff_words->plus.text.ptr
 696 *
 697 *      that is: the plus text must start as a new line, and if there is no minus
 698 *      word printed, a graph prefix must be printed.
 699 *
 700 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 701 *      *(diff_words->current_plus - 1) == '\n'
 702 *
 703 *      that is: a graph prefix must be printed following a '\n'
 704 */
 705static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 706{
 707        if ((diff_words->last_minus == 0 &&
 708                diff_words->current_plus == diff_words->plus.text.ptr) ||
 709                (diff_words->current_plus > diff_words->plus.text.ptr &&
 710                *(diff_words->current_plus - 1) == '\n')) {
 711                return 1;
 712        } else {
 713                return 0;
 714        }
 715}
 716
 717static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 718{
 719        struct diff_words_data *diff_words = priv;
 720        struct diff_words_style *style = diff_words->style;
 721        int minus_first, minus_len, plus_first, plus_len;
 722        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 723        struct diff_options *opt = diff_words->opt;
 724        struct strbuf *msgbuf;
 725        char *line_prefix = "";
 726
 727        if (line[0] != '@' || parse_hunk_header(line, len,
 728                        &minus_first, &minus_len, &plus_first, &plus_len))
 729                return;
 730
 731        assert(opt);
 732        if (opt->output_prefix) {
 733                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 734                line_prefix = msgbuf->buf;
 735        }
 736
 737        /* POSIX requires that first be decremented by one if len == 0... */
 738        if (minus_len) {
 739                minus_begin = diff_words->minus.orig[minus_first].begin;
 740                minus_end =
 741                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 742        } else
 743                minus_begin = minus_end =
 744                        diff_words->minus.orig[minus_first].end;
 745
 746        if (plus_len) {
 747                plus_begin = diff_words->plus.orig[plus_first].begin;
 748                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 749        } else
 750                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 751
 752        if (color_words_output_graph_prefix(diff_words)) {
 753                fputs(line_prefix, diff_words->opt->file);
 754        }
 755        if (diff_words->current_plus != plus_begin) {
 756                fn_out_diff_words_write_helper(diff_words->opt->file,
 757                                &style->ctx, style->newline,
 758                                plus_begin - diff_words->current_plus,
 759                                diff_words->current_plus, line_prefix);
 760                if (*(plus_begin - 1) == '\n')
 761                        fputs(line_prefix, diff_words->opt->file);
 762        }
 763        if (minus_begin != minus_end) {
 764                fn_out_diff_words_write_helper(diff_words->opt->file,
 765                                &style->old, style->newline,
 766                                minus_end - minus_begin, minus_begin,
 767                                line_prefix);
 768        }
 769        if (plus_begin != plus_end) {
 770                fn_out_diff_words_write_helper(diff_words->opt->file,
 771                                &style->new, style->newline,
 772                                plus_end - plus_begin, plus_begin,
 773                                line_prefix);
 774        }
 775
 776        diff_words->current_plus = plus_end;
 777        diff_words->last_minus = minus_first;
 778}
 779
 780/* This function starts looking at *begin, and returns 0 iff a word was found. */
 781static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 782                int *begin, int *end)
 783{
 784        if (word_regex && *begin < buffer->size) {
 785                regmatch_t match[1];
 786                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 787                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 788                                        '\n', match[0].rm_eo - match[0].rm_so);
 789                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 790                        *begin += match[0].rm_so;
 791                        return *begin >= *end;
 792                }
 793                return -1;
 794        }
 795
 796        /* find the next word */
 797        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 798                (*begin)++;
 799        if (*begin >= buffer->size)
 800                return -1;
 801
 802        /* find the end of the word */
 803        *end = *begin + 1;
 804        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 805                (*end)++;
 806
 807        return 0;
 808}
 809
 810/*
 811 * This function splits the words in buffer->text, stores the list with
 812 * newline separator into out, and saves the offsets of the original words
 813 * in buffer->orig.
 814 */
 815static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 816                regex_t *word_regex)
 817{
 818        int i, j;
 819        long alloc = 0;
 820
 821        out->size = 0;
 822        out->ptr = NULL;
 823
 824        /* fake an empty "0th" word */
 825        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 826        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 827        buffer->orig_nr = 1;
 828
 829        for (i = 0; i < buffer->text.size; i++) {
 830                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 831                        return;
 832
 833                /* store original boundaries */
 834                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 835                                buffer->orig_alloc);
 836                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 837                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 838                buffer->orig_nr++;
 839
 840                /* store one word */
 841                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 842                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 843                out->ptr[out->size + j - i] = '\n';
 844                out->size += j - i + 1;
 845
 846                i = j - 1;
 847        }
 848}
 849
 850/* this executes the word diff on the accumulated buffers */
 851static void diff_words_show(struct diff_words_data *diff_words)
 852{
 853        xpparam_t xpp;
 854        xdemitconf_t xecfg;
 855        mmfile_t minus, plus;
 856        struct diff_words_style *style = diff_words->style;
 857
 858        struct diff_options *opt = diff_words->opt;
 859        struct strbuf *msgbuf;
 860        char *line_prefix = "";
 861
 862        assert(opt);
 863        if (opt->output_prefix) {
 864                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 865                line_prefix = msgbuf->buf;
 866        }
 867
 868        /* special case: only removal */
 869        if (!diff_words->plus.text.size) {
 870                fputs(line_prefix, diff_words->opt->file);
 871                fn_out_diff_words_write_helper(diff_words->opt->file,
 872                        &style->old, style->newline,
 873                        diff_words->minus.text.size,
 874                        diff_words->minus.text.ptr, line_prefix);
 875                diff_words->minus.text.size = 0;
 876                return;
 877        }
 878
 879        diff_words->current_plus = diff_words->plus.text.ptr;
 880        diff_words->last_minus = 0;
 881
 882        memset(&xpp, 0, sizeof(xpp));
 883        memset(&xecfg, 0, sizeof(xecfg));
 884        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 885        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 886        xpp.flags = 0;
 887        /* as only the hunk header will be parsed, we need a 0-context */
 888        xecfg.ctxlen = 0;
 889        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 890                      &xpp, &xecfg);
 891        free(minus.ptr);
 892        free(plus.ptr);
 893        if (diff_words->current_plus != diff_words->plus.text.ptr +
 894                        diff_words->plus.text.size) {
 895                if (color_words_output_graph_prefix(diff_words))
 896                        fputs(line_prefix, diff_words->opt->file);
 897                fn_out_diff_words_write_helper(diff_words->opt->file,
 898                        &style->ctx, style->newline,
 899                        diff_words->plus.text.ptr + diff_words->plus.text.size
 900                        - diff_words->current_plus, diff_words->current_plus,
 901                        line_prefix);
 902        }
 903        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 904}
 905
 906/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 907static void diff_words_flush(struct emit_callback *ecbdata)
 908{
 909        if (ecbdata->diff_words->minus.text.size ||
 910            ecbdata->diff_words->plus.text.size)
 911                diff_words_show(ecbdata->diff_words);
 912}
 913
 914static void free_diff_words_data(struct emit_callback *ecbdata)
 915{
 916        if (ecbdata->diff_words) {
 917                diff_words_flush(ecbdata);
 918                free (ecbdata->diff_words->minus.text.ptr);
 919                free (ecbdata->diff_words->minus.orig);
 920                free (ecbdata->diff_words->plus.text.ptr);
 921                free (ecbdata->diff_words->plus.orig);
 922                if (ecbdata->diff_words->word_regex) {
 923                        regfree(ecbdata->diff_words->word_regex);
 924                        free(ecbdata->diff_words->word_regex);
 925                }
 926                free(ecbdata->diff_words);
 927                ecbdata->diff_words = NULL;
 928        }
 929}
 930
 931const char *diff_get_color(int diff_use_color, enum color_diff ix)
 932{
 933        if (diff_use_color)
 934                return diff_colors[ix];
 935        return "";
 936}
 937
 938static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 939{
 940        const char *cp;
 941        unsigned long allot;
 942        size_t l = len;
 943
 944        if (ecb->truncate)
 945                return ecb->truncate(line, len);
 946        cp = line;
 947        allot = l;
 948        while (0 < l) {
 949                (void) utf8_width(&cp, &l);
 950                if (!cp)
 951                        break; /* truncated in the middle? */
 952        }
 953        return allot - l;
 954}
 955
 956static void find_lno(const char *line, struct emit_callback *ecbdata)
 957{
 958        const char *p;
 959        ecbdata->lno_in_preimage = 0;
 960        ecbdata->lno_in_postimage = 0;
 961        p = strchr(line, '-');
 962        if (!p)
 963                return; /* cannot happen */
 964        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 965        p = strchr(p, '+');
 966        if (!p)
 967                return; /* cannot happen */
 968        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 969}
 970
 971static void fn_out_consume(void *priv, char *line, unsigned long len)
 972{
 973        struct emit_callback *ecbdata = priv;
 974        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 975        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 976        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 977        struct diff_options *o = ecbdata->opt;
 978        char *line_prefix = "";
 979        struct strbuf *msgbuf;
 980
 981        if (o && o->output_prefix) {
 982                msgbuf = o->output_prefix(o, o->output_prefix_data);
 983                line_prefix = msgbuf->buf;
 984        }
 985
 986        if (ecbdata->header) {
 987                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 988                strbuf_reset(ecbdata->header);
 989                ecbdata->header = NULL;
 990        }
 991        *(ecbdata->found_changesp) = 1;
 992
 993        if (ecbdata->label_path[0]) {
 994                const char *name_a_tab, *name_b_tab;
 995
 996                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 997                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 998
 999                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1000                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1001                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1002                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1003                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1004        }
1005
1006        if (diff_suppress_blank_empty
1007            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1008                line[0] = '\n';
1009                len = 1;
1010        }
1011
1012        if (line[0] == '@') {
1013                if (ecbdata->diff_words)
1014                        diff_words_flush(ecbdata);
1015                len = sane_truncate_line(ecbdata, line, len);
1016                find_lno(line, ecbdata);
1017                emit_hunk_header(ecbdata, line, len);
1018                if (line[len-1] != '\n')
1019                        putc('\n', ecbdata->opt->file);
1020                return;
1021        }
1022
1023        if (len < 1) {
1024                emit_line(ecbdata->opt, reset, reset, line, len);
1025                if (ecbdata->diff_words
1026                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1027                        fputs("~\n", ecbdata->opt->file);
1028                return;
1029        }
1030
1031        if (ecbdata->diff_words) {
1032                if (line[0] == '-') {
1033                        diff_words_append(line, len,
1034                                          &ecbdata->diff_words->minus);
1035                        return;
1036                } else if (line[0] == '+') {
1037                        diff_words_append(line, len,
1038                                          &ecbdata->diff_words->plus);
1039                        return;
1040                }
1041                diff_words_flush(ecbdata);
1042                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1043                        emit_line(ecbdata->opt, plain, reset, line, len);
1044                        fputs("~\n", ecbdata->opt->file);
1045                } else {
1046                        /* don't print the prefix character */
1047                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1048                }
1049                return;
1050        }
1051
1052        if (line[0] != '+') {
1053                const char *color =
1054                        diff_get_color(ecbdata->color_diff,
1055                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1056                ecbdata->lno_in_preimage++;
1057                if (line[0] == ' ')
1058                        ecbdata->lno_in_postimage++;
1059                emit_line(ecbdata->opt, color, reset, line, len);
1060        } else {
1061                ecbdata->lno_in_postimage++;
1062                emit_add_line(reset, ecbdata, line + 1, len - 1);
1063        }
1064}
1065
1066static char *pprint_rename(const char *a, const char *b)
1067{
1068        const char *old = a;
1069        const char *new = b;
1070        struct strbuf name = STRBUF_INIT;
1071        int pfx_length, sfx_length;
1072        int len_a = strlen(a);
1073        int len_b = strlen(b);
1074        int a_midlen, b_midlen;
1075        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1076        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1077
1078        if (qlen_a || qlen_b) {
1079                quote_c_style(a, &name, NULL, 0);
1080                strbuf_addstr(&name, " => ");
1081                quote_c_style(b, &name, NULL, 0);
1082                return strbuf_detach(&name, NULL);
1083        }
1084
1085        /* Find common prefix */
1086        pfx_length = 0;
1087        while (*old && *new && *old == *new) {
1088                if (*old == '/')
1089                        pfx_length = old - a + 1;
1090                old++;
1091                new++;
1092        }
1093
1094        /* Find common suffix */
1095        old = a + len_a;
1096        new = b + len_b;
1097        sfx_length = 0;
1098        while (a <= old && b <= new && *old == *new) {
1099                if (*old == '/')
1100                        sfx_length = len_a - (old - a);
1101                old--;
1102                new--;
1103        }
1104
1105        /*
1106         * pfx{mid-a => mid-b}sfx
1107         * {pfx-a => pfx-b}sfx
1108         * pfx{sfx-a => sfx-b}
1109         * name-a => name-b
1110         */
1111        a_midlen = len_a - pfx_length - sfx_length;
1112        b_midlen = len_b - pfx_length - sfx_length;
1113        if (a_midlen < 0)
1114                a_midlen = 0;
1115        if (b_midlen < 0)
1116                b_midlen = 0;
1117
1118        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1119        if (pfx_length + sfx_length) {
1120                strbuf_add(&name, a, pfx_length);
1121                strbuf_addch(&name, '{');
1122        }
1123        strbuf_add(&name, a + pfx_length, a_midlen);
1124        strbuf_addstr(&name, " => ");
1125        strbuf_add(&name, b + pfx_length, b_midlen);
1126        if (pfx_length + sfx_length) {
1127                strbuf_addch(&name, '}');
1128                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1129        }
1130        return strbuf_detach(&name, NULL);
1131}
1132
1133struct diffstat_t {
1134        int nr;
1135        int alloc;
1136        struct diffstat_file {
1137                char *from_name;
1138                char *name;
1139                char *print_name;
1140                unsigned is_unmerged:1;
1141                unsigned is_binary:1;
1142                unsigned is_renamed:1;
1143                uintmax_t added, deleted;
1144        } **files;
1145};
1146
1147static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1148                                          const char *name_a,
1149                                          const char *name_b)
1150{
1151        struct diffstat_file *x;
1152        x = xcalloc(sizeof (*x), 1);
1153        if (diffstat->nr == diffstat->alloc) {
1154                diffstat->alloc = alloc_nr(diffstat->alloc);
1155                diffstat->files = xrealloc(diffstat->files,
1156                                diffstat->alloc * sizeof(x));
1157        }
1158        diffstat->files[diffstat->nr++] = x;
1159        if (name_b) {
1160                x->from_name = xstrdup(name_a);
1161                x->name = xstrdup(name_b);
1162                x->is_renamed = 1;
1163        }
1164        else {
1165                x->from_name = NULL;
1166                x->name = xstrdup(name_a);
1167        }
1168        return x;
1169}
1170
1171static void diffstat_consume(void *priv, char *line, unsigned long len)
1172{
1173        struct diffstat_t *diffstat = priv;
1174        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1175
1176        if (line[0] == '+')
1177                x->added++;
1178        else if (line[0] == '-')
1179                x->deleted++;
1180}
1181
1182const char mime_boundary_leader[] = "------------";
1183
1184static int scale_linear(int it, int width, int max_change)
1185{
1186        /*
1187         * make sure that at least one '-' is printed if there were deletions,
1188         * and likewise for '+'.
1189         */
1190        if (max_change < 2)
1191                return it;
1192        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1193}
1194
1195static void show_name(FILE *file,
1196                      const char *prefix, const char *name, int len)
1197{
1198        fprintf(file, " %s%-*s |", prefix, len, name);
1199}
1200
1201static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1202{
1203        if (cnt <= 0)
1204                return;
1205        fprintf(file, "%s", set);
1206        while (cnt--)
1207                putc(ch, file);
1208        fprintf(file, "%s", reset);
1209}
1210
1211static void fill_print_name(struct diffstat_file *file)
1212{
1213        char *pname;
1214
1215        if (file->print_name)
1216                return;
1217
1218        if (!file->is_renamed) {
1219                struct strbuf buf = STRBUF_INIT;
1220                if (quote_c_style(file->name, &buf, NULL, 0)) {
1221                        pname = strbuf_detach(&buf, NULL);
1222                } else {
1223                        pname = file->name;
1224                        strbuf_release(&buf);
1225                }
1226        } else {
1227                pname = pprint_rename(file->from_name, file->name);
1228        }
1229        file->print_name = pname;
1230}
1231
1232static void show_stats(struct diffstat_t *data, struct diff_options *options)
1233{
1234        int i, len, add, del, adds = 0, dels = 0;
1235        uintmax_t max_change = 0, max_len = 0;
1236        int total_files = data->nr;
1237        int width, name_width;
1238        const char *reset, *set, *add_c, *del_c;
1239        const char *line_prefix = "";
1240        struct strbuf *msg = NULL;
1241
1242        if (data->nr == 0)
1243                return;
1244
1245        if (options->output_prefix) {
1246                msg = options->output_prefix(options, options->output_prefix_data);
1247                line_prefix = msg->buf;
1248        }
1249
1250        width = options->stat_width ? options->stat_width : 80;
1251        name_width = options->stat_name_width ? options->stat_name_width : 50;
1252
1253        /* Sanity: give at least 5 columns to the graph,
1254         * but leave at least 10 columns for the name.
1255         */
1256        if (width < 25)
1257                width = 25;
1258        if (name_width < 10)
1259                name_width = 10;
1260        else if (width < name_width + 15)
1261                name_width = width - 15;
1262
1263        /* Find the longest filename and max number of changes */
1264        reset = diff_get_color_opt(options, DIFF_RESET);
1265        set   = diff_get_color_opt(options, DIFF_PLAIN);
1266        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1267        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1268
1269        for (i = 0; i < data->nr; i++) {
1270                struct diffstat_file *file = data->files[i];
1271                uintmax_t change = file->added + file->deleted;
1272                fill_print_name(file);
1273                len = strlen(file->print_name);
1274                if (max_len < len)
1275                        max_len = len;
1276
1277                if (file->is_binary || file->is_unmerged)
1278                        continue;
1279                if (max_change < change)
1280                        max_change = change;
1281        }
1282
1283        /* Compute the width of the graph part;
1284         * 10 is for one blank at the beginning of the line plus
1285         * " | count " between the name and the graph.
1286         *
1287         * From here on, name_width is the width of the name area,
1288         * and width is the width of the graph area.
1289         */
1290        name_width = (name_width < max_len) ? name_width : max_len;
1291        if (width < (name_width + 10) + max_change)
1292                width = width - (name_width + 10);
1293        else
1294                width = max_change;
1295
1296        for (i = 0; i < data->nr; i++) {
1297                const char *prefix = "";
1298                char *name = data->files[i]->print_name;
1299                uintmax_t added = data->files[i]->added;
1300                uintmax_t deleted = data->files[i]->deleted;
1301                int name_len;
1302
1303                /*
1304                 * "scale" the filename
1305                 */
1306                len = name_width;
1307                name_len = strlen(name);
1308                if (name_width < name_len) {
1309                        char *slash;
1310                        prefix = "...";
1311                        len -= 3;
1312                        name += name_len - len;
1313                        slash = strchr(name, '/');
1314                        if (slash)
1315                                name = slash;
1316                }
1317
1318                if (data->files[i]->is_binary) {
1319                        fprintf(options->file, "%s", line_prefix);
1320                        show_name(options->file, prefix, name, len);
1321                        fprintf(options->file, "  Bin ");
1322                        fprintf(options->file, "%s%"PRIuMAX"%s",
1323                                del_c, deleted, reset);
1324                        fprintf(options->file, " -> ");
1325                        fprintf(options->file, "%s%"PRIuMAX"%s",
1326                                add_c, added, reset);
1327                        fprintf(options->file, " bytes");
1328                        fprintf(options->file, "\n");
1329                        continue;
1330                }
1331                else if (data->files[i]->is_unmerged) {
1332                        fprintf(options->file, "%s", line_prefix);
1333                        show_name(options->file, prefix, name, len);
1334                        fprintf(options->file, "  Unmerged\n");
1335                        continue;
1336                }
1337                else if (!data->files[i]->is_renamed &&
1338                         (added + deleted == 0)) {
1339                        total_files--;
1340                        continue;
1341                }
1342
1343                /*
1344                 * scale the add/delete
1345                 */
1346                add = added;
1347                del = deleted;
1348                adds += add;
1349                dels += del;
1350
1351                if (width <= max_change) {
1352                        add = scale_linear(add, width, max_change);
1353                        del = scale_linear(del, width, max_change);
1354                }
1355                fprintf(options->file, "%s", line_prefix);
1356                show_name(options->file, prefix, name, len);
1357                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1358                                added + deleted ? " " : "");
1359                show_graph(options->file, '+', add, add_c, reset);
1360                show_graph(options->file, '-', del, del_c, reset);
1361                fprintf(options->file, "\n");
1362        }
1363        fprintf(options->file, "%s", line_prefix);
1364        fprintf(options->file,
1365               " %d files changed, %d insertions(+), %d deletions(-)\n",
1366               total_files, adds, dels);
1367}
1368
1369static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1370{
1371        int i, adds = 0, dels = 0, total_files = data->nr;
1372
1373        if (data->nr == 0)
1374                return;
1375
1376        for (i = 0; i < data->nr; i++) {
1377                if (!data->files[i]->is_binary &&
1378                    !data->files[i]->is_unmerged) {
1379                        int added = data->files[i]->added;
1380                        int deleted= data->files[i]->deleted;
1381                        if (!data->files[i]->is_renamed &&
1382                            (added + deleted == 0)) {
1383                                total_files--;
1384                        } else {
1385                                adds += added;
1386                                dels += deleted;
1387                        }
1388                }
1389        }
1390        if (options->output_prefix) {
1391                struct strbuf *msg = NULL;
1392                msg = options->output_prefix(options,
1393                                options->output_prefix_data);
1394                fprintf(options->file, "%s", msg->buf);
1395        }
1396        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1397               total_files, adds, dels);
1398}
1399
1400static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1401{
1402        int i;
1403
1404        if (data->nr == 0)
1405                return;
1406
1407        for (i = 0; i < data->nr; i++) {
1408                struct diffstat_file *file = data->files[i];
1409
1410                if (options->output_prefix) {
1411                        struct strbuf *msg = NULL;
1412                        msg = options->output_prefix(options,
1413                                        options->output_prefix_data);
1414                        fprintf(options->file, "%s", msg->buf);
1415                }
1416
1417                if (file->is_binary)
1418                        fprintf(options->file, "-\t-\t");
1419                else
1420                        fprintf(options->file,
1421                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1422                                file->added, file->deleted);
1423                if (options->line_termination) {
1424                        fill_print_name(file);
1425                        if (!file->is_renamed)
1426                                write_name_quoted(file->name, options->file,
1427                                                  options->line_termination);
1428                        else {
1429                                fputs(file->print_name, options->file);
1430                                putc(options->line_termination, options->file);
1431                        }
1432                } else {
1433                        if (file->is_renamed) {
1434                                putc('\0', options->file);
1435                                write_name_quoted(file->from_name, options->file, '\0');
1436                        }
1437                        write_name_quoted(file->name, options->file, '\0');
1438                }
1439        }
1440}
1441
1442struct dirstat_file {
1443        const char *name;
1444        unsigned long changed;
1445};
1446
1447struct dirstat_dir {
1448        struct dirstat_file *files;
1449        int alloc, nr, percent, cumulative;
1450};
1451
1452static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1453                unsigned long changed, const char *base, int baselen)
1454{
1455        unsigned long this_dir = 0;
1456        unsigned int sources = 0;
1457        const char *line_prefix = "";
1458        struct strbuf *msg = NULL;
1459
1460        if (opt->output_prefix) {
1461                msg = opt->output_prefix(opt, opt->output_prefix_data);
1462                line_prefix = msg->buf;
1463        }
1464
1465        while (dir->nr) {
1466                struct dirstat_file *f = dir->files;
1467                int namelen = strlen(f->name);
1468                unsigned long this;
1469                char *slash;
1470
1471                if (namelen < baselen)
1472                        break;
1473                if (memcmp(f->name, base, baselen))
1474                        break;
1475                slash = strchr(f->name + baselen, '/');
1476                if (slash) {
1477                        int newbaselen = slash + 1 - f->name;
1478                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1479                        sources++;
1480                } else {
1481                        this = f->changed;
1482                        dir->files++;
1483                        dir->nr--;
1484                        sources += 2;
1485                }
1486                this_dir += this;
1487        }
1488
1489        /*
1490         * We don't report dirstat's for
1491         *  - the top level
1492         *  - or cases where everything came from a single directory
1493         *    under this directory (sources == 1).
1494         */
1495        if (baselen && sources != 1) {
1496                int permille = this_dir * 1000 / changed;
1497                if (permille) {
1498                        int percent = permille / 10;
1499                        if (percent >= dir->percent) {
1500                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1501                                        percent, permille % 10, baselen, base);
1502                                if (!dir->cumulative)
1503                                        return 0;
1504                        }
1505                }
1506        }
1507        return this_dir;
1508}
1509
1510static int dirstat_compare(const void *_a, const void *_b)
1511{
1512        const struct dirstat_file *a = _a;
1513        const struct dirstat_file *b = _b;
1514        return strcmp(a->name, b->name);
1515}
1516
1517static void show_dirstat(struct diff_options *options)
1518{
1519        int i;
1520        unsigned long changed;
1521        struct dirstat_dir dir;
1522        struct diff_queue_struct *q = &diff_queued_diff;
1523
1524        dir.files = NULL;
1525        dir.alloc = 0;
1526        dir.nr = 0;
1527        dir.percent = options->dirstat_percent;
1528        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1529
1530        changed = 0;
1531        for (i = 0; i < q->nr; i++) {
1532                struct diff_filepair *p = q->queue[i];
1533                const char *name;
1534                unsigned long copied, added, damage;
1535
1536                name = p->one->path ? p->one->path : p->two->path;
1537
1538                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1539                        diff_populate_filespec(p->one, 0);
1540                        diff_populate_filespec(p->two, 0);
1541                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1542                                               &copied, &added);
1543                        diff_free_filespec_data(p->one);
1544                        diff_free_filespec_data(p->two);
1545                } else if (DIFF_FILE_VALID(p->one)) {
1546                        diff_populate_filespec(p->one, 1);
1547                        copied = added = 0;
1548                        diff_free_filespec_data(p->one);
1549                } else if (DIFF_FILE_VALID(p->two)) {
1550                        diff_populate_filespec(p->two, 1);
1551                        copied = 0;
1552                        added = p->two->size;
1553                        diff_free_filespec_data(p->two);
1554                } else
1555                        continue;
1556
1557                /*
1558                 * Original minus copied is the removed material,
1559                 * added is the new material.  They are both damages
1560                 * made to the preimage. In --dirstat-by-file mode, count
1561                 * damaged files, not damaged lines. This is done by
1562                 * counting only a single damaged line per file.
1563                 */
1564                damage = (p->one->size - copied) + added;
1565                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1566                        damage = 1;
1567
1568                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1569                dir.files[dir.nr].name = name;
1570                dir.files[dir.nr].changed = damage;
1571                changed += damage;
1572                dir.nr++;
1573        }
1574
1575        /* This can happen even with many files, if everything was renames */
1576        if (!changed)
1577                return;
1578
1579        /* Show all directories with more than x% of the changes */
1580        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1581        gather_dirstat(options, &dir, changed, "", 0);
1582}
1583
1584static void free_diffstat_info(struct diffstat_t *diffstat)
1585{
1586        int i;
1587        for (i = 0; i < diffstat->nr; i++) {
1588                struct diffstat_file *f = diffstat->files[i];
1589                if (f->name != f->print_name)
1590                        free(f->print_name);
1591                free(f->name);
1592                free(f->from_name);
1593                free(f);
1594        }
1595        free(diffstat->files);
1596}
1597
1598struct checkdiff_t {
1599        const char *filename;
1600        int lineno;
1601        int conflict_marker_size;
1602        struct diff_options *o;
1603        unsigned ws_rule;
1604        unsigned status;
1605};
1606
1607static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1608{
1609        char firstchar;
1610        int cnt;
1611
1612        if (len < marker_size + 1)
1613                return 0;
1614        firstchar = line[0];
1615        switch (firstchar) {
1616        case '=': case '>': case '<': case '|':
1617                break;
1618        default:
1619                return 0;
1620        }
1621        for (cnt = 1; cnt < marker_size; cnt++)
1622                if (line[cnt] != firstchar)
1623                        return 0;
1624        /* line[1] thru line[marker_size-1] are same as firstchar */
1625        if (len < marker_size + 1 || !isspace(line[marker_size]))
1626                return 0;
1627        return 1;
1628}
1629
1630static void checkdiff_consume(void *priv, char *line, unsigned long len)
1631{
1632        struct checkdiff_t *data = priv;
1633        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1634        int marker_size = data->conflict_marker_size;
1635        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1636        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1637        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1638        char *err;
1639        char *line_prefix = "";
1640        struct strbuf *msgbuf;
1641
1642        assert(data->o);
1643        if (data->o->output_prefix) {
1644                msgbuf = data->o->output_prefix(data->o,
1645                        data->o->output_prefix_data);
1646                line_prefix = msgbuf->buf;
1647        }
1648
1649        if (line[0] == '+') {
1650                unsigned bad;
1651                data->lineno++;
1652                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1653                        data->status |= 1;
1654                        fprintf(data->o->file,
1655                                "%s%s:%d: leftover conflict marker\n",
1656                                line_prefix, data->filename, data->lineno);
1657                }
1658                bad = ws_check(line + 1, len - 1, data->ws_rule);
1659                if (!bad)
1660                        return;
1661                data->status |= bad;
1662                err = whitespace_error_string(bad);
1663                fprintf(data->o->file, "%s%s:%d: %s.\n",
1664                        line_prefix, data->filename, data->lineno, err);
1665                free(err);
1666                emit_line(data->o, set, reset, line, 1);
1667                ws_check_emit(line + 1, len - 1, data->ws_rule,
1668                              data->o->file, set, reset, ws);
1669        } else if (line[0] == ' ') {
1670                data->lineno++;
1671        } else if (line[0] == '@') {
1672                char *plus = strchr(line, '+');
1673                if (plus)
1674                        data->lineno = strtol(plus, NULL, 10) - 1;
1675                else
1676                        die("invalid diff");
1677        }
1678}
1679
1680static unsigned char *deflate_it(char *data,
1681                                 unsigned long size,
1682                                 unsigned long *result_size)
1683{
1684        int bound;
1685        unsigned char *deflated;
1686        z_stream stream;
1687
1688        memset(&stream, 0, sizeof(stream));
1689        deflateInit(&stream, zlib_compression_level);
1690        bound = deflateBound(&stream, size);
1691        deflated = xmalloc(bound);
1692        stream.next_out = deflated;
1693        stream.avail_out = bound;
1694
1695        stream.next_in = (unsigned char *)data;
1696        stream.avail_in = size;
1697        while (deflate(&stream, Z_FINISH) == Z_OK)
1698                ; /* nothing */
1699        deflateEnd(&stream);
1700        *result_size = stream.total_out;
1701        return deflated;
1702}
1703
1704static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1705{
1706        void *cp;
1707        void *delta;
1708        void *deflated;
1709        void *data;
1710        unsigned long orig_size;
1711        unsigned long delta_size;
1712        unsigned long deflate_size;
1713        unsigned long data_size;
1714
1715        /* We could do deflated delta, or we could do just deflated two,
1716         * whichever is smaller.
1717         */
1718        delta = NULL;
1719        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1720        if (one->size && two->size) {
1721                delta = diff_delta(one->ptr, one->size,
1722                                   two->ptr, two->size,
1723                                   &delta_size, deflate_size);
1724                if (delta) {
1725                        void *to_free = delta;
1726                        orig_size = delta_size;
1727                        delta = deflate_it(delta, delta_size, &delta_size);
1728                        free(to_free);
1729                }
1730        }
1731
1732        if (delta && delta_size < deflate_size) {
1733                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1734                free(deflated);
1735                data = delta;
1736                data_size = delta_size;
1737        }
1738        else {
1739                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1740                free(delta);
1741                data = deflated;
1742                data_size = deflate_size;
1743        }
1744
1745        /* emit data encoded in base85 */
1746        cp = data;
1747        while (data_size) {
1748                int bytes = (52 < data_size) ? 52 : data_size;
1749                char line[70];
1750                data_size -= bytes;
1751                if (bytes <= 26)
1752                        line[0] = bytes + 'A' - 1;
1753                else
1754                        line[0] = bytes - 26 + 'a' - 1;
1755                encode_85(line + 1, cp, bytes);
1756                cp = (char *) cp + bytes;
1757                fprintf(file, "%s", prefix);
1758                fputs(line, file);
1759                fputc('\n', file);
1760        }
1761        fprintf(file, "%s\n", prefix);
1762        free(data);
1763}
1764
1765static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1766{
1767        fprintf(file, "%sGIT binary patch\n", prefix);
1768        emit_binary_diff_body(file, one, two, prefix);
1769        emit_binary_diff_body(file, two, one, prefix);
1770}
1771
1772static void diff_filespec_load_driver(struct diff_filespec *one)
1773{
1774        /* Use already-loaded driver */
1775        if (one->driver)
1776                return;
1777
1778        if (S_ISREG(one->mode))
1779                one->driver = userdiff_find_by_path(one->path);
1780
1781        /* Fallback to default settings */
1782        if (!one->driver)
1783                one->driver = userdiff_find_by_name("default");
1784}
1785
1786int diff_filespec_is_binary(struct diff_filespec *one)
1787{
1788        if (one->is_binary == -1) {
1789                diff_filespec_load_driver(one);
1790                if (one->driver->binary != -1)
1791                        one->is_binary = one->driver->binary;
1792                else {
1793                        if (!one->data && DIFF_FILE_VALID(one))
1794                                diff_populate_filespec(one, 0);
1795                        if (one->data)
1796                                one->is_binary = buffer_is_binary(one->data,
1797                                                one->size);
1798                        if (one->is_binary == -1)
1799                                one->is_binary = 0;
1800                }
1801        }
1802        return one->is_binary;
1803}
1804
1805static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1806{
1807        diff_filespec_load_driver(one);
1808        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1809}
1810
1811static const char *userdiff_word_regex(struct diff_filespec *one)
1812{
1813        diff_filespec_load_driver(one);
1814        return one->driver->word_regex;
1815}
1816
1817void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1818{
1819        if (!options->a_prefix)
1820                options->a_prefix = a;
1821        if (!options->b_prefix)
1822                options->b_prefix = b;
1823}
1824
1825struct userdiff_driver *get_textconv(struct diff_filespec *one)
1826{
1827        if (!DIFF_FILE_VALID(one))
1828                return NULL;
1829
1830        diff_filespec_load_driver(one);
1831        if (!one->driver->textconv)
1832                return NULL;
1833
1834        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1835                struct notes_cache *c = xmalloc(sizeof(*c));
1836                struct strbuf name = STRBUF_INIT;
1837
1838                strbuf_addf(&name, "textconv/%s", one->driver->name);
1839                notes_cache_init(c, name.buf, one->driver->textconv);
1840                one->driver->textconv_cache = c;
1841        }
1842
1843        return one->driver;
1844}
1845
1846static void builtin_diff(const char *name_a,
1847                         const char *name_b,
1848                         struct diff_filespec *one,
1849                         struct diff_filespec *two,
1850                         const char *xfrm_msg,
1851                         int must_show_header,
1852                         struct diff_options *o,
1853                         int complete_rewrite)
1854{
1855        mmfile_t mf1, mf2;
1856        const char *lbl[2];
1857        char *a_one, *b_two;
1858        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1859        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1860        const char *a_prefix, *b_prefix;
1861        struct userdiff_driver *textconv_one = NULL;
1862        struct userdiff_driver *textconv_two = NULL;
1863        struct strbuf header = STRBUF_INIT;
1864        struct strbuf *msgbuf;
1865        char *line_prefix = "";
1866
1867        if (o->output_prefix) {
1868                msgbuf = o->output_prefix(o, o->output_prefix_data);
1869                line_prefix = msgbuf->buf;
1870        }
1871
1872        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1873                        (!one->mode || S_ISGITLINK(one->mode)) &&
1874                        (!two->mode || S_ISGITLINK(two->mode))) {
1875                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1876                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1877                show_submodule_summary(o->file, one ? one->path : two->path,
1878                                one->sha1, two->sha1, two->dirty_submodule,
1879                                del, add, reset);
1880                return;
1881        }
1882
1883        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1884                textconv_one = get_textconv(one);
1885                textconv_two = get_textconv(two);
1886        }
1887
1888        diff_set_mnemonic_prefix(o, "a/", "b/");
1889        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1890                a_prefix = o->b_prefix;
1891                b_prefix = o->a_prefix;
1892        } else {
1893                a_prefix = o->a_prefix;
1894                b_prefix = o->b_prefix;
1895        }
1896
1897        /* Never use a non-valid filename anywhere if at all possible */
1898        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1899        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1900
1901        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1902        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1903        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1904        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1905        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1906        if (lbl[0][0] == '/') {
1907                /* /dev/null */
1908                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1909                if (xfrm_msg)
1910                        strbuf_addstr(&header, xfrm_msg);
1911                must_show_header = 1;
1912        }
1913        else if (lbl[1][0] == '/') {
1914                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1915                if (xfrm_msg)
1916                        strbuf_addstr(&header, xfrm_msg);
1917                must_show_header = 1;
1918        }
1919        else {
1920                if (one->mode != two->mode) {
1921                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1922                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1923                        must_show_header = 1;
1924                }
1925                if (xfrm_msg)
1926                        strbuf_addstr(&header, xfrm_msg);
1927
1928                /*
1929                 * we do not run diff between different kind
1930                 * of objects.
1931                 */
1932                if ((one->mode ^ two->mode) & S_IFMT)
1933                        goto free_ab_and_return;
1934                if (complete_rewrite &&
1935                    (textconv_one || !diff_filespec_is_binary(one)) &&
1936                    (textconv_two || !diff_filespec_is_binary(two))) {
1937                        fprintf(o->file, "%s", header.buf);
1938                        strbuf_reset(&header);
1939                        emit_rewrite_diff(name_a, name_b, one, two,
1940                                                textconv_one, textconv_two, o);
1941                        o->found_changes = 1;
1942                        goto free_ab_and_return;
1943                }
1944        }
1945
1946        if (!DIFF_OPT_TST(o, TEXT) &&
1947            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1948              (!textconv_two && diff_filespec_is_binary(two)) )) {
1949                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1950                        die("unable to read files to diff");
1951                /* Quite common confusing case */
1952                if (mf1.size == mf2.size &&
1953                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1954                        if (must_show_header)
1955                                fprintf(o->file, "%s", header.buf);
1956                        goto free_ab_and_return;
1957                }
1958                fprintf(o->file, "%s", header.buf);
1959                strbuf_reset(&header);
1960                if (DIFF_OPT_TST(o, BINARY))
1961                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1962                else
1963                        fprintf(o->file, "%sBinary files %s and %s differ\n",
1964                                line_prefix, lbl[0], lbl[1]);
1965                o->found_changes = 1;
1966        }
1967        else {
1968                /* Crazy xdl interfaces.. */
1969                const char *diffopts = getenv("GIT_DIFF_OPTS");
1970                xpparam_t xpp;
1971                xdemitconf_t xecfg;
1972                struct emit_callback ecbdata;
1973                const struct userdiff_funcname *pe;
1974
1975                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
1976                        fprintf(o->file, "%s", header.buf);
1977                        strbuf_reset(&header);
1978                }
1979
1980                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1981                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1982
1983                pe = diff_funcname_pattern(one);
1984                if (!pe)
1985                        pe = diff_funcname_pattern(two);
1986
1987                memset(&xpp, 0, sizeof(xpp));
1988                memset(&xecfg, 0, sizeof(xecfg));
1989                memset(&ecbdata, 0, sizeof(ecbdata));
1990                ecbdata.label_path = lbl;
1991                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1992                ecbdata.found_changesp = &o->found_changes;
1993                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1994                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1995                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1996                ecbdata.opt = o;
1997                ecbdata.header = header.len ? &header : NULL;
1998                xpp.flags = o->xdl_opts;
1999                xecfg.ctxlen = o->context;
2000                xecfg.interhunkctxlen = o->interhunkcontext;
2001                xecfg.flags = XDL_EMIT_FUNCNAMES;
2002                if (pe)
2003                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2004                if (!diffopts)
2005                        ;
2006                else if (!prefixcmp(diffopts, "--unified="))
2007                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2008                else if (!prefixcmp(diffopts, "-u"))
2009                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2010                if (o->word_diff) {
2011                        int i;
2012
2013                        ecbdata.diff_words =
2014                                xcalloc(1, sizeof(struct diff_words_data));
2015                        ecbdata.diff_words->type = o->word_diff;
2016                        ecbdata.diff_words->opt = o;
2017                        if (!o->word_regex)
2018                                o->word_regex = userdiff_word_regex(one);
2019                        if (!o->word_regex)
2020                                o->word_regex = userdiff_word_regex(two);
2021                        if (!o->word_regex)
2022                                o->word_regex = diff_word_regex_cfg;
2023                        if (o->word_regex) {
2024                                ecbdata.diff_words->word_regex = (regex_t *)
2025                                        xmalloc(sizeof(regex_t));
2026                                if (regcomp(ecbdata.diff_words->word_regex,
2027                                                o->word_regex,
2028                                                REG_EXTENDED | REG_NEWLINE))
2029                                        die ("Invalid regular expression: %s",
2030                                                        o->word_regex);
2031                        }
2032                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2033                                if (o->word_diff == diff_words_styles[i].type) {
2034                                        ecbdata.diff_words->style =
2035                                                &diff_words_styles[i];
2036                                        break;
2037                                }
2038                        }
2039                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2040                                struct diff_words_style *st = ecbdata.diff_words->style;
2041                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2042                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2043                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2044                        }
2045                }
2046                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2047                              &xpp, &xecfg);
2048                if (o->word_diff)
2049                        free_diff_words_data(&ecbdata);
2050                if (textconv_one)
2051                        free(mf1.ptr);
2052                if (textconv_two)
2053                        free(mf2.ptr);
2054                xdiff_clear_find_func(&xecfg);
2055        }
2056
2057 free_ab_and_return:
2058        strbuf_release(&header);
2059        diff_free_filespec_data(one);
2060        diff_free_filespec_data(two);
2061        free(a_one);
2062        free(b_two);
2063        return;
2064}
2065
2066static void builtin_diffstat(const char *name_a, const char *name_b,
2067                             struct diff_filespec *one,
2068                             struct diff_filespec *two,
2069                             struct diffstat_t *diffstat,
2070                             struct diff_options *o,
2071                             int complete_rewrite)
2072{
2073        mmfile_t mf1, mf2;
2074        struct diffstat_file *data;
2075
2076        data = diffstat_add(diffstat, name_a, name_b);
2077
2078        if (!one || !two) {
2079                data->is_unmerged = 1;
2080                return;
2081        }
2082        if (complete_rewrite) {
2083                diff_populate_filespec(one, 0);
2084                diff_populate_filespec(two, 0);
2085                data->deleted = count_lines(one->data, one->size);
2086                data->added = count_lines(two->data, two->size);
2087                goto free_and_return;
2088        }
2089        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2090                die("unable to read files to diff");
2091
2092        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2093                data->is_binary = 1;
2094                data->added = mf2.size;
2095                data->deleted = mf1.size;
2096        } else {
2097                /* Crazy xdl interfaces.. */
2098                xpparam_t xpp;
2099                xdemitconf_t xecfg;
2100
2101                memset(&xpp, 0, sizeof(xpp));
2102                memset(&xecfg, 0, sizeof(xecfg));
2103                xpp.flags = o->xdl_opts;
2104                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2105                              &xpp, &xecfg);
2106        }
2107
2108 free_and_return:
2109        diff_free_filespec_data(one);
2110        diff_free_filespec_data(two);
2111}
2112
2113static void builtin_checkdiff(const char *name_a, const char *name_b,
2114                              const char *attr_path,
2115                              struct diff_filespec *one,
2116                              struct diff_filespec *two,
2117                              struct diff_options *o)
2118{
2119        mmfile_t mf1, mf2;
2120        struct checkdiff_t data;
2121
2122        if (!two)
2123                return;
2124
2125        memset(&data, 0, sizeof(data));
2126        data.filename = name_b ? name_b : name_a;
2127        data.lineno = 0;
2128        data.o = o;
2129        data.ws_rule = whitespace_rule(attr_path);
2130        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2131
2132        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2133                die("unable to read files to diff");
2134
2135        /*
2136         * All the other codepaths check both sides, but not checking
2137         * the "old" side here is deliberate.  We are checking the newly
2138         * introduced changes, and as long as the "new" side is text, we
2139         * can and should check what it introduces.
2140         */
2141        if (diff_filespec_is_binary(two))
2142                goto free_and_return;
2143        else {
2144                /* Crazy xdl interfaces.. */
2145                xpparam_t xpp;
2146                xdemitconf_t xecfg;
2147
2148                memset(&xpp, 0, sizeof(xpp));
2149                memset(&xecfg, 0, sizeof(xecfg));
2150                xecfg.ctxlen = 1; /* at least one context line */
2151                xpp.flags = 0;
2152                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2153                              &xpp, &xecfg);
2154
2155                if (data.ws_rule & WS_BLANK_AT_EOF) {
2156                        struct emit_callback ecbdata;
2157                        int blank_at_eof;
2158
2159                        ecbdata.ws_rule = data.ws_rule;
2160                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2161                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2162
2163                        if (blank_at_eof) {
2164                                static char *err;
2165                                if (!err)
2166                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2167                                fprintf(o->file, "%s:%d: %s.\n",
2168                                        data.filename, blank_at_eof, err);
2169                                data.status = 1; /* report errors */
2170                        }
2171                }
2172        }
2173 free_and_return:
2174        diff_free_filespec_data(one);
2175        diff_free_filespec_data(two);
2176        if (data.status)
2177                DIFF_OPT_SET(o, CHECK_FAILED);
2178}
2179
2180struct diff_filespec *alloc_filespec(const char *path)
2181{
2182        int namelen = strlen(path);
2183        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2184
2185        memset(spec, 0, sizeof(*spec));
2186        spec->path = (char *)(spec + 1);
2187        memcpy(spec->path, path, namelen+1);
2188        spec->count = 1;
2189        spec->is_binary = -1;
2190        return spec;
2191}
2192
2193void free_filespec(struct diff_filespec *spec)
2194{
2195        if (!--spec->count) {
2196                diff_free_filespec_data(spec);
2197                free(spec);
2198        }
2199}
2200
2201void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2202                   unsigned short mode)
2203{
2204        if (mode) {
2205                spec->mode = canon_mode(mode);
2206                hashcpy(spec->sha1, sha1);
2207                spec->sha1_valid = !is_null_sha1(sha1);
2208        }
2209}
2210
2211/*
2212 * Given a name and sha1 pair, if the index tells us the file in
2213 * the work tree has that object contents, return true, so that
2214 * prepare_temp_file() does not have to inflate and extract.
2215 */
2216static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2217{
2218        struct cache_entry *ce;
2219        struct stat st;
2220        int pos, len;
2221
2222        /*
2223         * We do not read the cache ourselves here, because the
2224         * benchmark with my previous version that always reads cache
2225         * shows that it makes things worse for diff-tree comparing
2226         * two linux-2.6 kernel trees in an already checked out work
2227         * tree.  This is because most diff-tree comparisons deal with
2228         * only a small number of files, while reading the cache is
2229         * expensive for a large project, and its cost outweighs the
2230         * savings we get by not inflating the object to a temporary
2231         * file.  Practically, this code only helps when we are used
2232         * by diff-cache --cached, which does read the cache before
2233         * calling us.
2234         */
2235        if (!active_cache)
2236                return 0;
2237
2238        /* We want to avoid the working directory if our caller
2239         * doesn't need the data in a normal file, this system
2240         * is rather slow with its stat/open/mmap/close syscalls,
2241         * and the object is contained in a pack file.  The pack
2242         * is probably already open and will be faster to obtain
2243         * the data through than the working directory.  Loose
2244         * objects however would tend to be slower as they need
2245         * to be individually opened and inflated.
2246         */
2247        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2248                return 0;
2249
2250        len = strlen(name);
2251        pos = cache_name_pos(name, len);
2252        if (pos < 0)
2253                return 0;
2254        ce = active_cache[pos];
2255
2256        /*
2257         * This is not the sha1 we are looking for, or
2258         * unreusable because it is not a regular file.
2259         */
2260        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2261                return 0;
2262
2263        /*
2264         * If ce is marked as "assume unchanged", there is no
2265         * guarantee that work tree matches what we are looking for.
2266         */
2267        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2268                return 0;
2269
2270        /*
2271         * If ce matches the file in the work tree, we can reuse it.
2272         */
2273        if (ce_uptodate(ce) ||
2274            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2275                return 1;
2276
2277        return 0;
2278}
2279
2280static int populate_from_stdin(struct diff_filespec *s)
2281{
2282        struct strbuf buf = STRBUF_INIT;
2283        size_t size = 0;
2284
2285        if (strbuf_read(&buf, 0, 0) < 0)
2286                return error("error while reading from stdin %s",
2287                                     strerror(errno));
2288
2289        s->should_munmap = 0;
2290        s->data = strbuf_detach(&buf, &size);
2291        s->size = size;
2292        s->should_free = 1;
2293        return 0;
2294}
2295
2296static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2297{
2298        int len;
2299        char *data = xmalloc(100), *dirty = "";
2300
2301        /* Are we looking at the work tree? */
2302        if (s->dirty_submodule)
2303                dirty = "-dirty";
2304
2305        len = snprintf(data, 100,
2306                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2307        s->data = data;
2308        s->size = len;
2309        s->should_free = 1;
2310        if (size_only) {
2311                s->data = NULL;
2312                free(data);
2313        }
2314        return 0;
2315}
2316
2317/*
2318 * While doing rename detection and pickaxe operation, we may need to
2319 * grab the data for the blob (or file) for our own in-core comparison.
2320 * diff_filespec has data and size fields for this purpose.
2321 */
2322int diff_populate_filespec(struct diff_filespec *s, int size_only)
2323{
2324        int err = 0;
2325        if (!DIFF_FILE_VALID(s))
2326                die("internal error: asking to populate invalid file.");
2327        if (S_ISDIR(s->mode))
2328                return -1;
2329
2330        if (s->data)
2331                return 0;
2332
2333        if (size_only && 0 < s->size)
2334                return 0;
2335
2336        if (S_ISGITLINK(s->mode))
2337                return diff_populate_gitlink(s, size_only);
2338
2339        if (!s->sha1_valid ||
2340            reuse_worktree_file(s->path, s->sha1, 0)) {
2341                struct strbuf buf = STRBUF_INIT;
2342                struct stat st;
2343                int fd;
2344
2345                if (!strcmp(s->path, "-"))
2346                        return populate_from_stdin(s);
2347
2348                if (lstat(s->path, &st) < 0) {
2349                        if (errno == ENOENT) {
2350                        err_empty:
2351                                err = -1;
2352                        empty:
2353                                s->data = (char *)"";
2354                                s->size = 0;
2355                                return err;
2356                        }
2357                }
2358                s->size = xsize_t(st.st_size);
2359                if (!s->size)
2360                        goto empty;
2361                if (S_ISLNK(st.st_mode)) {
2362                        struct strbuf sb = STRBUF_INIT;
2363
2364                        if (strbuf_readlink(&sb, s->path, s->size))
2365                                goto err_empty;
2366                        s->size = sb.len;
2367                        s->data = strbuf_detach(&sb, NULL);
2368                        s->should_free = 1;
2369                        return 0;
2370                }
2371                if (size_only)
2372                        return 0;
2373                fd = open(s->path, O_RDONLY);
2374                if (fd < 0)
2375                        goto err_empty;
2376                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2377                close(fd);
2378                s->should_munmap = 1;
2379
2380                /*
2381                 * Convert from working tree format to canonical git format
2382                 */
2383                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2384                        size_t size = 0;
2385                        munmap(s->data, s->size);
2386                        s->should_munmap = 0;
2387                        s->data = strbuf_detach(&buf, &size);
2388                        s->size = size;
2389                        s->should_free = 1;
2390                }
2391        }
2392        else {
2393                enum object_type type;
2394                if (size_only) {
2395                        type = sha1_object_info(s->sha1, &s->size);
2396                        if (type < 0)
2397                                die("unable to read %s", sha1_to_hex(s->sha1));
2398                } else {
2399                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2400                        if (!s->data)
2401                                die("unable to read %s", sha1_to_hex(s->sha1));
2402                        s->should_free = 1;
2403                }
2404        }
2405        return 0;
2406}
2407
2408void diff_free_filespec_blob(struct diff_filespec *s)
2409{
2410        if (s->should_free)
2411                free(s->data);
2412        else if (s->should_munmap)
2413                munmap(s->data, s->size);
2414
2415        if (s->should_free || s->should_munmap) {
2416                s->should_free = s->should_munmap = 0;
2417                s->data = NULL;
2418        }
2419}
2420
2421void diff_free_filespec_data(struct diff_filespec *s)
2422{
2423        diff_free_filespec_blob(s);
2424        free(s->cnt_data);
2425        s->cnt_data = NULL;
2426}
2427
2428static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2429                           void *blob,
2430                           unsigned long size,
2431                           const unsigned char *sha1,
2432                           int mode)
2433{
2434        int fd;
2435        struct strbuf buf = STRBUF_INIT;
2436        struct strbuf template = STRBUF_INIT;
2437        char *path_dup = xstrdup(path);
2438        const char *base = basename(path_dup);
2439
2440        /* Generate "XXXXXX_basename.ext" */
2441        strbuf_addstr(&template, "XXXXXX_");
2442        strbuf_addstr(&template, base);
2443
2444        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2445                        strlen(base) + 1);
2446        if (fd < 0)
2447                die_errno("unable to create temp-file");
2448        if (convert_to_working_tree(path,
2449                        (const char *)blob, (size_t)size, &buf)) {
2450                blob = buf.buf;
2451                size = buf.len;
2452        }
2453        if (write_in_full(fd, blob, size) != size)
2454                die_errno("unable to write temp-file");
2455        close(fd);
2456        temp->name = temp->tmp_path;
2457        strcpy(temp->hex, sha1_to_hex(sha1));
2458        temp->hex[40] = 0;
2459        sprintf(temp->mode, "%06o", mode);
2460        strbuf_release(&buf);
2461        strbuf_release(&template);
2462        free(path_dup);
2463}
2464
2465static struct diff_tempfile *prepare_temp_file(const char *name,
2466                struct diff_filespec *one)
2467{
2468        struct diff_tempfile *temp = claim_diff_tempfile();
2469
2470        if (!DIFF_FILE_VALID(one)) {
2471        not_a_valid_file:
2472                /* A '-' entry produces this for file-2, and
2473                 * a '+' entry produces this for file-1.
2474                 */
2475                temp->name = "/dev/null";
2476                strcpy(temp->hex, ".");
2477                strcpy(temp->mode, ".");
2478                return temp;
2479        }
2480
2481        if (!remove_tempfile_installed) {
2482                atexit(remove_tempfile);
2483                sigchain_push_common(remove_tempfile_on_signal);
2484                remove_tempfile_installed = 1;
2485        }
2486
2487        if (!one->sha1_valid ||
2488            reuse_worktree_file(name, one->sha1, 1)) {
2489                struct stat st;
2490                if (lstat(name, &st) < 0) {
2491                        if (errno == ENOENT)
2492                                goto not_a_valid_file;
2493                        die_errno("stat(%s)", name);
2494                }
2495                if (S_ISLNK(st.st_mode)) {
2496                        struct strbuf sb = STRBUF_INIT;
2497                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2498                                die_errno("readlink(%s)", name);
2499                        prep_temp_blob(name, temp, sb.buf, sb.len,
2500                                       (one->sha1_valid ?
2501                                        one->sha1 : null_sha1),
2502                                       (one->sha1_valid ?
2503                                        one->mode : S_IFLNK));
2504                        strbuf_release(&sb);
2505                }
2506                else {
2507                        /* we can borrow from the file in the work tree */
2508                        temp->name = name;
2509                        if (!one->sha1_valid)
2510                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2511                        else
2512                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2513                        /* Even though we may sometimes borrow the
2514                         * contents from the work tree, we always want
2515                         * one->mode.  mode is trustworthy even when
2516                         * !(one->sha1_valid), as long as
2517                         * DIFF_FILE_VALID(one).
2518                         */
2519                        sprintf(temp->mode, "%06o", one->mode);
2520                }
2521                return temp;
2522        }
2523        else {
2524                if (diff_populate_filespec(one, 0))
2525                        die("cannot read data blob for %s", one->path);
2526                prep_temp_blob(name, temp, one->data, one->size,
2527                               one->sha1, one->mode);
2528        }
2529        return temp;
2530}
2531
2532/* An external diff command takes:
2533 *
2534 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2535 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2536 *
2537 */
2538static void run_external_diff(const char *pgm,
2539                              const char *name,
2540                              const char *other,
2541                              struct diff_filespec *one,
2542                              struct diff_filespec *two,
2543                              const char *xfrm_msg,
2544                              int complete_rewrite)
2545{
2546        const char *spawn_arg[10];
2547        int retval;
2548        const char **arg = &spawn_arg[0];
2549
2550        if (one && two) {
2551                struct diff_tempfile *temp_one, *temp_two;
2552                const char *othername = (other ? other : name);
2553                temp_one = prepare_temp_file(name, one);
2554                temp_two = prepare_temp_file(othername, two);
2555                *arg++ = pgm;
2556                *arg++ = name;
2557                *arg++ = temp_one->name;
2558                *arg++ = temp_one->hex;
2559                *arg++ = temp_one->mode;
2560                *arg++ = temp_two->name;
2561                *arg++ = temp_two->hex;
2562                *arg++ = temp_two->mode;
2563                if (other) {
2564                        *arg++ = other;
2565                        *arg++ = xfrm_msg;
2566                }
2567        } else {
2568                *arg++ = pgm;
2569                *arg++ = name;
2570        }
2571        *arg = NULL;
2572        fflush(NULL);
2573        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2574        remove_tempfile();
2575        if (retval) {
2576                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2577                exit(1);
2578        }
2579}
2580
2581static int similarity_index(struct diff_filepair *p)
2582{
2583        return p->score * 100 / MAX_SCORE;
2584}
2585
2586static void fill_metainfo(struct strbuf *msg,
2587                          const char *name,
2588                          const char *other,
2589                          struct diff_filespec *one,
2590                          struct diff_filespec *two,
2591                          struct diff_options *o,
2592                          struct diff_filepair *p,
2593                          int *must_show_header,
2594                          int use_color)
2595{
2596        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2597        const char *reset = diff_get_color(use_color, DIFF_RESET);
2598        struct strbuf *msgbuf;
2599        char *line_prefix = "";
2600
2601        *must_show_header = 1;
2602        if (o->output_prefix) {
2603                msgbuf = o->output_prefix(o, o->output_prefix_data);
2604                line_prefix = msgbuf->buf;
2605        }
2606        strbuf_init(msg, PATH_MAX * 2 + 300);
2607        switch (p->status) {
2608        case DIFF_STATUS_COPIED:
2609                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2610                            line_prefix, set, similarity_index(p));
2611                strbuf_addf(msg, "%s\n%s%scopy from ",
2612                            reset,  line_prefix, set);
2613                quote_c_style(name, msg, NULL, 0);
2614                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2615                quote_c_style(other, msg, NULL, 0);
2616                strbuf_addf(msg, "%s\n", reset);
2617                break;
2618        case DIFF_STATUS_RENAMED:
2619                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2620                            line_prefix, set, similarity_index(p));
2621                strbuf_addf(msg, "%s\n%s%srename from ",
2622                            reset, line_prefix, set);
2623                quote_c_style(name, msg, NULL, 0);
2624                strbuf_addf(msg, "%s\n%s%srename to ",
2625                            reset, line_prefix, set);
2626                quote_c_style(other, msg, NULL, 0);
2627                strbuf_addf(msg, "%s\n", reset);
2628                break;
2629        case DIFF_STATUS_MODIFIED:
2630                if (p->score) {
2631                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2632                                    line_prefix,
2633                                    set, similarity_index(p), reset);
2634                        break;
2635                }
2636                /* fallthru */
2637        default:
2638                *must_show_header = 0;
2639        }
2640        if (one && two && hashcmp(one->sha1, two->sha1)) {
2641                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2642
2643                if (DIFF_OPT_TST(o, BINARY)) {
2644                        mmfile_t mf;
2645                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2646                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2647                                abbrev = 40;
2648                }
2649                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2650                            find_unique_abbrev(one->sha1, abbrev));
2651                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2652                if (one->mode == two->mode)
2653                        strbuf_addf(msg, " %06o", one->mode);
2654                strbuf_addf(msg, "%s\n", reset);
2655        }
2656}
2657
2658static void run_diff_cmd(const char *pgm,
2659                         const char *name,
2660                         const char *other,
2661                         const char *attr_path,
2662                         struct diff_filespec *one,
2663                         struct diff_filespec *two,
2664                         struct strbuf *msg,
2665                         struct diff_options *o,
2666                         struct diff_filepair *p)
2667{
2668        const char *xfrm_msg = NULL;
2669        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2670        int must_show_header = 0;
2671
2672        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2673                pgm = NULL;
2674        else {
2675                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2676                if (drv && drv->external)
2677                        pgm = drv->external;
2678        }
2679
2680        if (msg) {
2681                /*
2682                 * don't use colors when the header is intended for an
2683                 * external diff driver
2684                 */
2685                fill_metainfo(msg, name, other, one, two, o, p,
2686                              &must_show_header,
2687                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2688                xfrm_msg = msg->len ? msg->buf : NULL;
2689        }
2690
2691        if (pgm) {
2692                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2693                                  complete_rewrite);
2694                return;
2695        }
2696        if (one && two)
2697                builtin_diff(name, other ? other : name,
2698                             one, two, xfrm_msg, must_show_header,
2699                             o, complete_rewrite);
2700        else
2701                fprintf(o->file, "* Unmerged path %s\n", name);
2702}
2703
2704static void diff_fill_sha1_info(struct diff_filespec *one)
2705{
2706        if (DIFF_FILE_VALID(one)) {
2707                if (!one->sha1_valid) {
2708                        struct stat st;
2709                        if (!strcmp(one->path, "-")) {
2710                                hashcpy(one->sha1, null_sha1);
2711                                return;
2712                        }
2713                        if (lstat(one->path, &st) < 0)
2714                                die_errno("stat '%s'", one->path);
2715                        if (index_path(one->sha1, one->path, &st, 0))
2716                                die("cannot hash %s", one->path);
2717                }
2718        }
2719        else
2720                hashclr(one->sha1);
2721}
2722
2723static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2724{
2725        /* Strip the prefix but do not molest /dev/null and absolute paths */
2726        if (*namep && **namep != '/') {
2727                *namep += prefix_length;
2728                if (**namep == '/')
2729                        ++*namep;
2730        }
2731        if (*otherp && **otherp != '/') {
2732                *otherp += prefix_length;
2733                if (**otherp == '/')
2734                        ++*otherp;
2735        }
2736}
2737
2738static void run_diff(struct diff_filepair *p, struct diff_options *o)
2739{
2740        const char *pgm = external_diff();
2741        struct strbuf msg;
2742        struct diff_filespec *one = p->one;
2743        struct diff_filespec *two = p->two;
2744        const char *name;
2745        const char *other;
2746        const char *attr_path;
2747
2748        name  = p->one->path;
2749        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2750        attr_path = name;
2751        if (o->prefix_length)
2752                strip_prefix(o->prefix_length, &name, &other);
2753
2754        if (DIFF_PAIR_UNMERGED(p)) {
2755                run_diff_cmd(pgm, name, NULL, attr_path,
2756                             NULL, NULL, NULL, o, p);
2757                return;
2758        }
2759
2760        diff_fill_sha1_info(one);
2761        diff_fill_sha1_info(two);
2762
2763        if (!pgm &&
2764            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2765            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2766                /*
2767                 * a filepair that changes between file and symlink
2768                 * needs to be split into deletion and creation.
2769                 */
2770                struct diff_filespec *null = alloc_filespec(two->path);
2771                run_diff_cmd(NULL, name, other, attr_path,
2772                             one, null, &msg, o, p);
2773                free(null);
2774                strbuf_release(&msg);
2775
2776                null = alloc_filespec(one->path);
2777                run_diff_cmd(NULL, name, other, attr_path,
2778                             null, two, &msg, o, p);
2779                free(null);
2780        }
2781        else
2782                run_diff_cmd(pgm, name, other, attr_path,
2783                             one, two, &msg, o, p);
2784
2785        strbuf_release(&msg);
2786}
2787
2788static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2789                         struct diffstat_t *diffstat)
2790{
2791        const char *name;
2792        const char *other;
2793        int complete_rewrite = 0;
2794
2795        if (DIFF_PAIR_UNMERGED(p)) {
2796                /* unmerged */
2797                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2798                return;
2799        }
2800
2801        name = p->one->path;
2802        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2803
2804        if (o->prefix_length)
2805                strip_prefix(o->prefix_length, &name, &other);
2806
2807        diff_fill_sha1_info(p->one);
2808        diff_fill_sha1_info(p->two);
2809
2810        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2811                complete_rewrite = 1;
2812        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2813}
2814
2815static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2816{
2817        const char *name;
2818        const char *other;
2819        const char *attr_path;
2820
2821        if (DIFF_PAIR_UNMERGED(p)) {
2822                /* unmerged */
2823                return;
2824        }
2825
2826        name = p->one->path;
2827        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2828        attr_path = other ? other : name;
2829
2830        if (o->prefix_length)
2831                strip_prefix(o->prefix_length, &name, &other);
2832
2833        diff_fill_sha1_info(p->one);
2834        diff_fill_sha1_info(p->two);
2835
2836        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2837}
2838
2839void diff_setup(struct diff_options *options)
2840{
2841        memcpy(options, &default_diff_options, sizeof(*options));
2842
2843        options->file = stdout;
2844
2845        options->line_termination = '\n';
2846        options->break_opt = -1;
2847        options->rename_limit = -1;
2848        options->dirstat_percent = 3;
2849        options->context = 3;
2850
2851        options->change = diff_change;
2852        options->add_remove = diff_addremove;
2853        if (diff_use_color_default > 0)
2854                DIFF_OPT_SET(options, COLOR_DIFF);
2855        options->detect_rename = diff_detect_rename_default;
2856
2857        if (diff_no_prefix) {
2858                options->a_prefix = options->b_prefix = "";
2859        } else if (!diff_mnemonic_prefix) {
2860                options->a_prefix = "a/";
2861                options->b_prefix = "b/";
2862        }
2863}
2864
2865int diff_setup_done(struct diff_options *options)
2866{
2867        int count = 0;
2868
2869        if (options->output_format & DIFF_FORMAT_NAME)
2870                count++;
2871        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2872                count++;
2873        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2874                count++;
2875        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2876                count++;
2877        if (count > 1)
2878                die("--name-only, --name-status, --check and -s are mutually exclusive");
2879
2880        /*
2881         * Most of the time we can say "there are changes"
2882         * only by checking if there are changed paths, but
2883         * --ignore-whitespace* options force us to look
2884         * inside contents.
2885         */
2886
2887        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2888            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2889            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2890                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2891        else
2892                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2893
2894        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2895                options->detect_rename = DIFF_DETECT_COPY;
2896
2897        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2898                options->prefix = NULL;
2899        if (options->prefix)
2900                options->prefix_length = strlen(options->prefix);
2901        else
2902                options->prefix_length = 0;
2903
2904        if (options->output_format & (DIFF_FORMAT_NAME |
2905                                      DIFF_FORMAT_NAME_STATUS |
2906                                      DIFF_FORMAT_CHECKDIFF |
2907                                      DIFF_FORMAT_NO_OUTPUT))
2908                options->output_format &= ~(DIFF_FORMAT_RAW |
2909                                            DIFF_FORMAT_NUMSTAT |
2910                                            DIFF_FORMAT_DIFFSTAT |
2911                                            DIFF_FORMAT_SHORTSTAT |
2912                                            DIFF_FORMAT_DIRSTAT |
2913                                            DIFF_FORMAT_SUMMARY |
2914                                            DIFF_FORMAT_PATCH);
2915
2916        /*
2917         * These cases always need recursive; we do not drop caller-supplied
2918         * recursive bits for other formats here.
2919         */
2920        if (options->output_format & (DIFF_FORMAT_PATCH |
2921                                      DIFF_FORMAT_NUMSTAT |
2922                                      DIFF_FORMAT_DIFFSTAT |
2923                                      DIFF_FORMAT_SHORTSTAT |
2924                                      DIFF_FORMAT_DIRSTAT |
2925                                      DIFF_FORMAT_SUMMARY |
2926                                      DIFF_FORMAT_CHECKDIFF))
2927                DIFF_OPT_SET(options, RECURSIVE);
2928        /*
2929         * Also pickaxe would not work very well if you do not say recursive
2930         */
2931        if (options->pickaxe)
2932                DIFF_OPT_SET(options, RECURSIVE);
2933        /*
2934         * When patches are generated, submodules diffed against the work tree
2935         * must be checked for dirtiness too so it can be shown in the output
2936         */
2937        if (options->output_format & DIFF_FORMAT_PATCH)
2938                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2939
2940        if (options->detect_rename && options->rename_limit < 0)
2941                options->rename_limit = diff_rename_limit_default;
2942        if (options->setup & DIFF_SETUP_USE_CACHE) {
2943                if (!active_cache)
2944                        /* read-cache does not die even when it fails
2945                         * so it is safe for us to do this here.  Also
2946                         * it does not smudge active_cache or active_nr
2947                         * when it fails, so we do not have to worry about
2948                         * cleaning it up ourselves either.
2949                         */
2950                        read_cache();
2951        }
2952        if (options->abbrev <= 0 || 40 < options->abbrev)
2953                options->abbrev = 40; /* full */
2954
2955        /*
2956         * It does not make sense to show the first hit we happened
2957         * to have found.  It does not make sense not to return with
2958         * exit code in such a case either.
2959         */
2960        if (DIFF_OPT_TST(options, QUICK)) {
2961                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2962                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2963        }
2964
2965        return 0;
2966}
2967
2968static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2969{
2970        char c, *eq;
2971        int len;
2972
2973        if (*arg != '-')
2974                return 0;
2975        c = *++arg;
2976        if (!c)
2977                return 0;
2978        if (c == arg_short) {
2979                c = *++arg;
2980                if (!c)
2981                        return 1;
2982                if (val && isdigit(c)) {
2983                        char *end;
2984                        int n = strtoul(arg, &end, 10);
2985                        if (*end)
2986                                return 0;
2987                        *val = n;
2988                        return 1;
2989                }
2990                return 0;
2991        }
2992        if (c != '-')
2993                return 0;
2994        arg++;
2995        eq = strchr(arg, '=');
2996        if (eq)
2997                len = eq - arg;
2998        else
2999                len = strlen(arg);
3000        if (!len || strncmp(arg, arg_long, len))
3001                return 0;
3002        if (eq) {
3003                int n;
3004                char *end;
3005                if (!isdigit(*++eq))
3006                        return 0;
3007                n = strtoul(eq, &end, 10);
3008                if (*end)
3009                        return 0;
3010                *val = n;
3011        }
3012        return 1;
3013}
3014
3015static int diff_scoreopt_parse(const char *opt);
3016
3017static inline int short_opt(char opt, const char **argv,
3018                            const char **optarg)
3019{
3020        const char *arg = argv[0];
3021        if (arg[0] != '-' || arg[1] != opt)
3022                return 0;
3023        if (arg[2] != '\0') {
3024                *optarg = arg + 2;
3025                return 1;
3026        }
3027        if (!argv[1])
3028                die("Option '%c' requires a value", opt);
3029        *optarg = argv[1];
3030        return 2;
3031}
3032
3033int parse_long_opt(const char *opt, const char **argv,
3034                   const char **optarg)
3035{
3036        const char *arg = argv[0];
3037        if (arg[0] != '-' || arg[1] != '-')
3038                return 0;
3039        arg += strlen("--");
3040        if (prefixcmp(arg, opt))
3041                return 0;
3042        arg += strlen(opt);
3043        if (*arg == '=') { /* sticked form: --option=value */
3044                *optarg = arg + 1;
3045                return 1;
3046        }
3047        if (*arg != '\0')
3048                return 0;
3049        /* separate form: --option value */
3050        if (!argv[1])
3051                die("Option '--%s' requires a value", opt);
3052        *optarg = argv[1];
3053        return 2;
3054}
3055
3056static int stat_opt(struct diff_options *options, const char **av)
3057{
3058        const char *arg = av[0];
3059        char *end;
3060        int width = options->stat_width;
3061        int name_width = options->stat_name_width;
3062        int argcount = 1;
3063
3064        arg += strlen("--stat");
3065        end = (char *)arg;
3066
3067        switch (*arg) {
3068        case '-':
3069                if (!prefixcmp(arg, "-width")) {
3070                        arg += strlen("-width");
3071                        if (*arg == '=')
3072                                width = strtoul(arg + 1, &end, 10);
3073                        else if (!*arg && !av[1])
3074                                die("Option '--stat-width' requires a value");
3075                        else if (!*arg) {
3076                                width = strtoul(av[1], &end, 10);
3077                                argcount = 2;
3078                        }
3079                } else if (!prefixcmp(arg, "-name-width")) {
3080                        arg += strlen("-name-width");
3081                        if (*arg == '=')
3082                                name_width = strtoul(arg + 1, &end, 10);
3083                        else if (!*arg && !av[1])
3084                                die("Option '--stat-name-width' requires a value");
3085                        else if (!*arg) {
3086                                name_width = strtoul(av[1], &end, 10);
3087                                argcount = 2;
3088                        }
3089                }
3090                break;
3091        case '=':
3092                width = strtoul(arg+1, &end, 10);
3093                if (*end == ',')
3094                        name_width = strtoul(end+1, &end, 10);
3095        }
3096
3097        /* Important! This checks all the error cases! */
3098        if (*end)
3099                return 0;
3100        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3101        options->stat_name_width = name_width;
3102        options->stat_width = width;
3103        return argcount;
3104}
3105
3106int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3107{
3108        const char *arg = av[0];
3109        const char *optarg;
3110        int argcount;
3111
3112        /* Output format options */
3113        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3114                options->output_format |= DIFF_FORMAT_PATCH;
3115        else if (opt_arg(arg, 'U', "unified", &options->context))
3116                options->output_format |= DIFF_FORMAT_PATCH;
3117        else if (!strcmp(arg, "--raw"))
3118                options->output_format |= DIFF_FORMAT_RAW;
3119        else if (!strcmp(arg, "--patch-with-raw"))
3120                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3121        else if (!strcmp(arg, "--numstat"))
3122                options->output_format |= DIFF_FORMAT_NUMSTAT;
3123        else if (!strcmp(arg, "--shortstat"))
3124                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3125        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3126                options->output_format |= DIFF_FORMAT_DIRSTAT;
3127        else if (!strcmp(arg, "--cumulative")) {
3128                options->output_format |= DIFF_FORMAT_DIRSTAT;
3129                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3130        } else if (opt_arg(arg, 0, "dirstat-by-file",
3131                           &options->dirstat_percent)) {
3132                options->output_format |= DIFF_FORMAT_DIRSTAT;
3133                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3134        }
3135        else if (!strcmp(arg, "--check"))
3136                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3137        else if (!strcmp(arg, "--summary"))
3138                options->output_format |= DIFF_FORMAT_SUMMARY;
3139        else if (!strcmp(arg, "--patch-with-stat"))
3140                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3141        else if (!strcmp(arg, "--name-only"))
3142                options->output_format |= DIFF_FORMAT_NAME;
3143        else if (!strcmp(arg, "--name-status"))
3144                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3145        else if (!strcmp(arg, "-s"))
3146                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3147        else if (!prefixcmp(arg, "--stat"))
3148                /* --stat, --stat-width, or --stat-name-width */
3149                return stat_opt(options, av);
3150
3151        /* renames options */
3152        else if (!prefixcmp(arg, "-B")) {
3153                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3154                        return -1;
3155        }
3156        else if (!prefixcmp(arg, "-M")) {
3157                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3158                        return -1;
3159                options->detect_rename = DIFF_DETECT_RENAME;
3160        }
3161        else if (!prefixcmp(arg, "-C")) {
3162                if (options->detect_rename == DIFF_DETECT_COPY)
3163                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3164                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3165                        return -1;
3166                options->detect_rename = DIFF_DETECT_COPY;
3167        }
3168        else if (!strcmp(arg, "--no-renames"))
3169                options->detect_rename = 0;
3170        else if (!strcmp(arg, "--relative"))
3171                DIFF_OPT_SET(options, RELATIVE_NAME);
3172        else if (!prefixcmp(arg, "--relative=")) {
3173                DIFF_OPT_SET(options, RELATIVE_NAME);
3174                options->prefix = arg + 11;
3175        }
3176
3177        /* xdiff options */
3178        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3179                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3180        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3181                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3182        else if (!strcmp(arg, "--ignore-space-at-eol"))
3183                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3184        else if (!strcmp(arg, "--patience"))
3185                DIFF_XDL_SET(options, PATIENCE_DIFF);
3186
3187        /* flags options */
3188        else if (!strcmp(arg, "--binary")) {
3189                options->output_format |= DIFF_FORMAT_PATCH;
3190                DIFF_OPT_SET(options, BINARY);
3191        }
3192        else if (!strcmp(arg, "--full-index"))
3193                DIFF_OPT_SET(options, FULL_INDEX);
3194        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3195                DIFF_OPT_SET(options, TEXT);
3196        else if (!strcmp(arg, "-R"))
3197                DIFF_OPT_SET(options, REVERSE_DIFF);
3198        else if (!strcmp(arg, "--find-copies-harder"))
3199                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3200        else if (!strcmp(arg, "--follow"))
3201                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3202        else if (!strcmp(arg, "--color"))
3203                DIFF_OPT_SET(options, COLOR_DIFF);
3204        else if (!prefixcmp(arg, "--color=")) {
3205                int value = git_config_colorbool(NULL, arg+8, -1);
3206                if (value == 0)
3207                        DIFF_OPT_CLR(options, COLOR_DIFF);
3208                else if (value > 0)
3209                        DIFF_OPT_SET(options, COLOR_DIFF);
3210                else
3211                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3212        }
3213        else if (!strcmp(arg, "--no-color"))
3214                DIFF_OPT_CLR(options, COLOR_DIFF);
3215        else if (!strcmp(arg, "--color-words")) {
3216                DIFF_OPT_SET(options, COLOR_DIFF);
3217                options->word_diff = DIFF_WORDS_COLOR;
3218        }
3219        else if (!prefixcmp(arg, "--color-words=")) {
3220                DIFF_OPT_SET(options, COLOR_DIFF);
3221                options->word_diff = DIFF_WORDS_COLOR;
3222                options->word_regex = arg + 14;
3223        }
3224        else if (!strcmp(arg, "--word-diff")) {
3225                if (options->word_diff == DIFF_WORDS_NONE)
3226                        options->word_diff = DIFF_WORDS_PLAIN;
3227        }
3228        else if (!prefixcmp(arg, "--word-diff=")) {
3229                const char *type = arg + 12;
3230                if (!strcmp(type, "plain"))
3231                        options->word_diff = DIFF_WORDS_PLAIN;
3232                else if (!strcmp(type, "color")) {
3233                        DIFF_OPT_SET(options, COLOR_DIFF);
3234                        options->word_diff = DIFF_WORDS_COLOR;
3235                }
3236                else if (!strcmp(type, "porcelain"))
3237                        options->word_diff = DIFF_WORDS_PORCELAIN;
3238                else if (!strcmp(type, "none"))
3239                        options->word_diff = DIFF_WORDS_NONE;
3240                else
3241                        die("bad --word-diff argument: %s", type);
3242        }
3243        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3244                if (options->word_diff == DIFF_WORDS_NONE)
3245                        options->word_diff = DIFF_WORDS_PLAIN;
3246                options->word_regex = optarg;
3247                return argcount;
3248        }
3249        else if (!strcmp(arg, "--exit-code"))
3250                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3251        else if (!strcmp(arg, "--quiet"))
3252                DIFF_OPT_SET(options, QUICK);
3253        else if (!strcmp(arg, "--ext-diff"))
3254                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3255        else if (!strcmp(arg, "--no-ext-diff"))
3256                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3257        else if (!strcmp(arg, "--textconv"))
3258                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3259        else if (!strcmp(arg, "--no-textconv"))
3260                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3261        else if (!strcmp(arg, "--ignore-submodules")) {
3262                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3263                handle_ignore_submodules_arg(options, "all");
3264        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3265                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3266                handle_ignore_submodules_arg(options, arg + 20);
3267        } else if (!strcmp(arg, "--submodule"))
3268                DIFF_OPT_SET(options, SUBMODULE_LOG);
3269        else if (!prefixcmp(arg, "--submodule=")) {
3270                if (!strcmp(arg + 12, "log"))
3271                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3272        }
3273
3274        /* misc options */
3275        else if (!strcmp(arg, "-z"))
3276                options->line_termination = 0;
3277        else if ((argcount = short_opt('l', av, &optarg))) {
3278                options->rename_limit = strtoul(optarg, NULL, 10);
3279                return argcount;
3280        }
3281        else if ((argcount = short_opt('S', av, &optarg))) {
3282                options->pickaxe = optarg;
3283                return argcount;
3284        }
3285        else if (!strcmp(arg, "--pickaxe-all"))
3286                options->pickaxe_opts = DIFF_PICKAXE_ALL;
3287        else if (!strcmp(arg, "--pickaxe-regex"))
3288                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
3289        else if ((argcount = short_opt('O', av, &optarg))) {
3290                options->orderfile = optarg;
3291                return argcount;
3292        }
3293        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3294                options->filter = optarg;
3295                return argcount;
3296        }
3297        else if (!strcmp(arg, "--abbrev"))
3298                options->abbrev = DEFAULT_ABBREV;
3299        else if (!prefixcmp(arg, "--abbrev=")) {
3300                options->abbrev = strtoul(arg + 9, NULL, 10);
3301                if (options->abbrev < MINIMUM_ABBREV)
3302                        options->abbrev = MINIMUM_ABBREV;
3303                else if (40 < options->abbrev)
3304                        options->abbrev = 40;
3305        }
3306        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3307                options->a_prefix = optarg;
3308                return argcount;
3309        }
3310        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3311                options->b_prefix = optarg;
3312                return argcount;
3313        }
3314        else if (!strcmp(arg, "--no-prefix"))
3315                options->a_prefix = options->b_prefix = "";
3316        else if (opt_arg(arg, '\0', "inter-hunk-context",
3317                         &options->interhunkcontext))
3318                ;
3319        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3320                options->file = fopen(optarg, "w");
3321                if (!options->file)
3322                        die_errno("Could not open '%s'", optarg);
3323                options->close_file = 1;
3324                return argcount;
3325        } else
3326                return 0;
3327        return 1;
3328}
3329
3330static int parse_num(const char **cp_p)
3331{
3332        unsigned long num, scale;
3333        int ch, dot;
3334        const char *cp = *cp_p;
3335
3336        num = 0;
3337        scale = 1;
3338        dot = 0;
3339        for (;;) {
3340                ch = *cp;
3341                if ( !dot && ch == '.' ) {
3342                        scale = 1;
3343                        dot = 1;
3344                } else if ( ch == '%' ) {
3345                        scale = dot ? scale*100 : 100;
3346                        cp++;   /* % is always at the end */
3347                        break;
3348                } else if ( ch >= '0' && ch <= '9' ) {
3349                        if ( scale < 100000 ) {
3350                                scale *= 10;
3351                                num = (num*10) + (ch-'0');
3352                        }
3353                } else {
3354                        break;
3355                }
3356                cp++;
3357        }
3358        *cp_p = cp;
3359
3360        /* user says num divided by scale and we say internally that
3361         * is MAX_SCORE * num / scale.
3362         */
3363        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3364}
3365
3366static int diff_scoreopt_parse(const char *opt)
3367{
3368        int opt1, opt2, cmd;
3369
3370        if (*opt++ != '-')
3371                return -1;
3372        cmd = *opt++;
3373        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3374                return -1; /* that is not a -M, -C nor -B option */
3375
3376        opt1 = parse_num(&opt);
3377        if (cmd != 'B')
3378                opt2 = 0;
3379        else {
3380                if (*opt == 0)
3381                        opt2 = 0;
3382                else if (*opt != '/')
3383                        return -1; /* we expect -B80/99 or -B80 */
3384                else {
3385                        opt++;
3386                        opt2 = parse_num(&opt);
3387                }
3388        }
3389        if (*opt != 0)
3390                return -1;
3391        return opt1 | (opt2 << 16);
3392}
3393
3394struct diff_queue_struct diff_queued_diff;
3395
3396void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3397{
3398        if (queue->alloc <= queue->nr) {
3399                queue->alloc = alloc_nr(queue->alloc);
3400                queue->queue = xrealloc(queue->queue,
3401                                        sizeof(dp) * queue->alloc);
3402        }
3403        queue->queue[queue->nr++] = dp;
3404}
3405
3406struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3407                                 struct diff_filespec *one,
3408                                 struct diff_filespec *two)
3409{
3410        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3411        dp->one = one;
3412        dp->two = two;
3413        if (queue)
3414                diff_q(queue, dp);
3415        return dp;
3416}
3417
3418void diff_free_filepair(struct diff_filepair *p)
3419{
3420        free_filespec(p->one);
3421        free_filespec(p->two);
3422        free(p);
3423}
3424
3425/* This is different from find_unique_abbrev() in that
3426 * it stuffs the result with dots for alignment.
3427 */
3428const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3429{
3430        int abblen;
3431        const char *abbrev;
3432        if (len == 40)
3433                return sha1_to_hex(sha1);
3434
3435        abbrev = find_unique_abbrev(sha1, len);
3436        abblen = strlen(abbrev);
3437        if (abblen < 37) {
3438                static char hex[41];
3439                if (len < abblen && abblen <= len + 2)
3440                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3441                else
3442                        sprintf(hex, "%s...", abbrev);
3443                return hex;
3444        }
3445        return sha1_to_hex(sha1);
3446}
3447
3448static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3449{
3450        int line_termination = opt->line_termination;
3451        int inter_name_termination = line_termination ? '\t' : '\0';
3452        if (opt->output_prefix) {
3453                struct strbuf *msg = NULL;
3454                msg = opt->output_prefix(opt, opt->output_prefix_data);
3455                fprintf(opt->file, "%s", msg->buf);
3456        }
3457
3458        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3459                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3460                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3461                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3462        }
3463        if (p->score) {
3464                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3465                        inter_name_termination);
3466        } else {
3467                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3468        }
3469
3470        if (p->status == DIFF_STATUS_COPIED ||
3471            p->status == DIFF_STATUS_RENAMED) {
3472                const char *name_a, *name_b;
3473                name_a = p->one->path;
3474                name_b = p->two->path;
3475                strip_prefix(opt->prefix_length, &name_a, &name_b);
3476                write_name_quoted(name_a, opt->file, inter_name_termination);
3477                write_name_quoted(name_b, opt->file, line_termination);
3478        } else {
3479                const char *name_a, *name_b;
3480                name_a = p->one->mode ? p->one->path : p->two->path;
3481                name_b = NULL;
3482                strip_prefix(opt->prefix_length, &name_a, &name_b);
3483                write_name_quoted(name_a, opt->file, line_termination);
3484        }
3485}
3486
3487int diff_unmodified_pair(struct diff_filepair *p)
3488{
3489        /* This function is written stricter than necessary to support
3490         * the currently implemented transformers, but the idea is to
3491         * let transformers to produce diff_filepairs any way they want,
3492         * and filter and clean them up here before producing the output.
3493         */
3494        struct diff_filespec *one = p->one, *two = p->two;
3495
3496        if (DIFF_PAIR_UNMERGED(p))
3497                return 0; /* unmerged is interesting */
3498
3499        /* deletion, addition, mode or type change
3500         * and rename are all interesting.
3501         */
3502        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3503            DIFF_PAIR_MODE_CHANGED(p) ||
3504            strcmp(one->path, two->path))
3505                return 0;
3506
3507        /* both are valid and point at the same path.  that is, we are
3508         * dealing with a change.
3509         */
3510        if (one->sha1_valid && two->sha1_valid &&
3511            !hashcmp(one->sha1, two->sha1) &&
3512            !one->dirty_submodule && !two->dirty_submodule)
3513                return 1; /* no change */
3514        if (!one->sha1_valid && !two->sha1_valid)
3515                return 1; /* both look at the same file on the filesystem. */
3516        return 0;
3517}
3518
3519static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3520{
3521        if (diff_unmodified_pair(p))
3522                return;
3523
3524        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3525            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3526                return; /* no tree diffs in patch format */
3527
3528        run_diff(p, o);
3529}
3530
3531static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3532                            struct diffstat_t *diffstat)
3533{
3534        if (diff_unmodified_pair(p))
3535                return;
3536
3537        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3538            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3539                return; /* no useful stat for tree diffs */
3540
3541        run_diffstat(p, o, diffstat);
3542}
3543
3544static void diff_flush_checkdiff(struct diff_filepair *p,
3545                struct diff_options *o)
3546{
3547        if (diff_unmodified_pair(p))
3548                return;
3549
3550        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3551            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3552                return; /* nothing to check in tree diffs */
3553
3554        run_checkdiff(p, o);
3555}
3556
3557int diff_queue_is_empty(void)
3558{
3559        struct diff_queue_struct *q = &diff_queued_diff;
3560        int i;
3561        for (i = 0; i < q->nr; i++)
3562                if (!diff_unmodified_pair(q->queue[i]))
3563                        return 0;
3564        return 1;
3565}
3566
3567#if DIFF_DEBUG
3568void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3569{
3570        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3571                x, one ? one : "",
3572                s->path,
3573                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3574                s->mode,
3575                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3576        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3577                x, one ? one : "",
3578                s->size, s->xfrm_flags);
3579}
3580
3581void diff_debug_filepair(const struct diff_filepair *p, int i)
3582{
3583        diff_debug_filespec(p->one, i, "one");
3584        diff_debug_filespec(p->two, i, "two");
3585        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3586                p->score, p->status ? p->status : '?',
3587                p->one->rename_used, p->broken_pair);
3588}
3589
3590void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3591{
3592        int i;
3593        if (msg)
3594                fprintf(stderr, "%s\n", msg);
3595        fprintf(stderr, "q->nr = %d\n", q->nr);
3596        for (i = 0; i < q->nr; i++) {
3597                struct diff_filepair *p = q->queue[i];
3598                diff_debug_filepair(p, i);
3599        }
3600}
3601#endif
3602
3603static void diff_resolve_rename_copy(void)
3604{
3605        int i;
3606        struct diff_filepair *p;
3607        struct diff_queue_struct *q = &diff_queued_diff;
3608
3609        diff_debug_queue("resolve-rename-copy", q);
3610
3611        for (i = 0; i < q->nr; i++) {
3612                p = q->queue[i];
3613                p->status = 0; /* undecided */
3614                if (DIFF_PAIR_UNMERGED(p))
3615                        p->status = DIFF_STATUS_UNMERGED;
3616                else if (!DIFF_FILE_VALID(p->one))
3617                        p->status = DIFF_STATUS_ADDED;
3618                else if (!DIFF_FILE_VALID(p->two))
3619                        p->status = DIFF_STATUS_DELETED;
3620                else if (DIFF_PAIR_TYPE_CHANGED(p))
3621                        p->status = DIFF_STATUS_TYPE_CHANGED;
3622
3623                /* from this point on, we are dealing with a pair
3624                 * whose both sides are valid and of the same type, i.e.
3625                 * either in-place edit or rename/copy edit.
3626                 */
3627                else if (DIFF_PAIR_RENAME(p)) {
3628                        /*
3629                         * A rename might have re-connected a broken
3630                         * pair up, causing the pathnames to be the
3631                         * same again. If so, that's not a rename at
3632                         * all, just a modification..
3633                         *
3634                         * Otherwise, see if this source was used for
3635                         * multiple renames, in which case we decrement
3636                         * the count, and call it a copy.
3637                         */
3638                        if (!strcmp(p->one->path, p->two->path))
3639                                p->status = DIFF_STATUS_MODIFIED;
3640                        else if (--p->one->rename_used > 0)
3641                                p->status = DIFF_STATUS_COPIED;
3642                        else
3643                                p->status = DIFF_STATUS_RENAMED;
3644                }
3645                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3646                         p->one->mode != p->two->mode ||
3647                         p->one->dirty_submodule ||
3648                         p->two->dirty_submodule ||
3649                         is_null_sha1(p->one->sha1))
3650                        p->status = DIFF_STATUS_MODIFIED;
3651                else {
3652                        /* This is a "no-change" entry and should not
3653                         * happen anymore, but prepare for broken callers.
3654                         */
3655                        error("feeding unmodified %s to diffcore",
3656                              p->one->path);
3657                        p->status = DIFF_STATUS_UNKNOWN;
3658                }
3659        }
3660        diff_debug_queue("resolve-rename-copy done", q);
3661}
3662
3663static int check_pair_status(struct diff_filepair *p)
3664{
3665        switch (p->status) {
3666        case DIFF_STATUS_UNKNOWN:
3667                return 0;
3668        case 0:
3669                die("internal error in diff-resolve-rename-copy");
3670        default:
3671                return 1;
3672        }
3673}
3674
3675static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3676{
3677        int fmt = opt->output_format;
3678
3679        if (fmt & DIFF_FORMAT_CHECKDIFF)
3680                diff_flush_checkdiff(p, opt);
3681        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3682                diff_flush_raw(p, opt);
3683        else if (fmt & DIFF_FORMAT_NAME) {
3684                const char *name_a, *name_b;
3685                name_a = p->two->path;
3686                name_b = NULL;
3687                strip_prefix(opt->prefix_length, &name_a, &name_b);
3688                write_name_quoted(name_a, opt->file, opt->line_termination);
3689        }
3690}
3691
3692static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3693{
3694        if (fs->mode)
3695                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3696        else
3697                fprintf(file, " %s ", newdelete);
3698        write_name_quoted(fs->path, file, '\n');
3699}
3700
3701
3702static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3703                const char *line_prefix)
3704{
3705        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3706                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3707                        p->two->mode, show_name ? ' ' : '\n');
3708                if (show_name) {
3709                        write_name_quoted(p->two->path, file, '\n');
3710                }
3711        }
3712}
3713
3714static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3715                        const char *line_prefix)
3716{
3717        char *names = pprint_rename(p->one->path, p->two->path);
3718
3719        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3720        free(names);
3721        show_mode_change(file, p, 0, line_prefix);
3722}
3723
3724static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3725{
3726        FILE *file = opt->file;
3727        char *line_prefix = "";
3728
3729        if (opt->output_prefix) {
3730                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3731                line_prefix = buf->buf;
3732        }
3733
3734        switch(p->status) {
3735        case DIFF_STATUS_DELETED:
3736                fputs(line_prefix, file);
3737                show_file_mode_name(file, "delete", p->one);
3738                break;
3739        case DIFF_STATUS_ADDED:
3740                fputs(line_prefix, file);
3741                show_file_mode_name(file, "create", p->two);
3742                break;
3743        case DIFF_STATUS_COPIED:
3744                fputs(line_prefix, file);
3745                show_rename_copy(file, "copy", p, line_prefix);
3746                break;
3747        case DIFF_STATUS_RENAMED:
3748                fputs(line_prefix, file);
3749                show_rename_copy(file, "rename", p, line_prefix);
3750                break;
3751        default:
3752                if (p->score) {
3753                        fprintf(file, "%s rewrite ", line_prefix);
3754                        write_name_quoted(p->two->path, file, ' ');
3755                        fprintf(file, "(%d%%)\n", similarity_index(p));
3756                }
3757                show_mode_change(file, p, !p->score, line_prefix);
3758                break;
3759        }
3760}
3761
3762struct patch_id_t {
3763        git_SHA_CTX *ctx;
3764        int patchlen;
3765};
3766
3767static int remove_space(char *line, int len)
3768{
3769        int i;
3770        char *dst = line;
3771        unsigned char c;
3772
3773        for (i = 0; i < len; i++)
3774                if (!isspace((c = line[i])))
3775                        *dst++ = c;
3776
3777        return dst - line;
3778}
3779
3780static void patch_id_consume(void *priv, char *line, unsigned long len)
3781{
3782        struct patch_id_t *data = priv;
3783        int new_len;
3784
3785        /* Ignore line numbers when computing the SHA1 of the patch */
3786        if (!prefixcmp(line, "@@ -"))
3787                return;
3788
3789        new_len = remove_space(line, len);
3790
3791        git_SHA1_Update(data->ctx, line, new_len);
3792        data->patchlen += new_len;
3793}
3794
3795/* returns 0 upon success, and writes result into sha1 */
3796static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3797{
3798        struct diff_queue_struct *q = &diff_queued_diff;
3799        int i;
3800        git_SHA_CTX ctx;
3801        struct patch_id_t data;
3802        char buffer[PATH_MAX * 4 + 20];
3803
3804        git_SHA1_Init(&ctx);
3805        memset(&data, 0, sizeof(struct patch_id_t));
3806        data.ctx = &ctx;
3807
3808        for (i = 0; i < q->nr; i++) {
3809                xpparam_t xpp;
3810                xdemitconf_t xecfg;
3811                mmfile_t mf1, mf2;
3812                struct diff_filepair *p = q->queue[i];
3813                int len1, len2;
3814
3815                memset(&xpp, 0, sizeof(xpp));
3816                memset(&xecfg, 0, sizeof(xecfg));
3817                if (p->status == 0)
3818                        return error("internal diff status error");
3819                if (p->status == DIFF_STATUS_UNKNOWN)
3820                        continue;
3821                if (diff_unmodified_pair(p))
3822                        continue;
3823                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3824                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3825                        continue;
3826                if (DIFF_PAIR_UNMERGED(p))
3827                        continue;
3828
3829                diff_fill_sha1_info(p->one);
3830                diff_fill_sha1_info(p->two);
3831                if (fill_mmfile(&mf1, p->one) < 0 ||
3832                                fill_mmfile(&mf2, p->two) < 0)
3833                        return error("unable to read files to diff");
3834
3835                len1 = remove_space(p->one->path, strlen(p->one->path));
3836                len2 = remove_space(p->two->path, strlen(p->two->path));
3837                if (p->one->mode == 0)
3838                        len1 = snprintf(buffer, sizeof(buffer),
3839                                        "diff--gita/%.*sb/%.*s"
3840                                        "newfilemode%06o"
3841                                        "---/dev/null"
3842                                        "+++b/%.*s",
3843                                        len1, p->one->path,
3844                                        len2, p->two->path,
3845                                        p->two->mode,
3846                                        len2, p->two->path);
3847                else if (p->two->mode == 0)
3848                        len1 = snprintf(buffer, sizeof(buffer),
3849                                        "diff--gita/%.*sb/%.*s"
3850                                        "deletedfilemode%06o"
3851                                        "---a/%.*s"
3852                                        "+++/dev/null",
3853                                        len1, p->one->path,
3854                                        len2, p->two->path,
3855                                        p->one->mode,
3856                                        len1, p->one->path);
3857                else
3858                        len1 = snprintf(buffer, sizeof(buffer),
3859                                        "diff--gita/%.*sb/%.*s"
3860                                        "---a/%.*s"
3861                                        "+++b/%.*s",
3862                                        len1, p->one->path,
3863                                        len2, p->two->path,
3864                                        len1, p->one->path,
3865                                        len2, p->two->path);
3866                git_SHA1_Update(&ctx, buffer, len1);
3867
3868                if (diff_filespec_is_binary(p->one) ||
3869                    diff_filespec_is_binary(p->two)) {
3870                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3871                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3872                        continue;
3873                }
3874
3875                xpp.flags = 0;
3876                xecfg.ctxlen = 3;
3877                xecfg.flags = 0;
3878                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3879                              &xpp, &xecfg);
3880        }
3881
3882        git_SHA1_Final(sha1, &ctx);
3883        return 0;
3884}
3885
3886int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3887{
3888        struct diff_queue_struct *q = &diff_queued_diff;
3889        int i;
3890        int result = diff_get_patch_id(options, sha1);
3891
3892        for (i = 0; i < q->nr; i++)
3893                diff_free_filepair(q->queue[i]);
3894
3895        free(q->queue);
3896        DIFF_QUEUE_CLEAR(q);
3897
3898        return result;
3899}
3900
3901static int is_summary_empty(const struct diff_queue_struct *q)
3902{
3903        int i;
3904
3905        for (i = 0; i < q->nr; i++) {
3906                const struct diff_filepair *p = q->queue[i];
3907
3908                switch (p->status) {
3909                case DIFF_STATUS_DELETED:
3910                case DIFF_STATUS_ADDED:
3911                case DIFF_STATUS_COPIED:
3912                case DIFF_STATUS_RENAMED:
3913                        return 0;
3914                default:
3915                        if (p->score)
3916                                return 0;
3917                        if (p->one->mode && p->two->mode &&
3918                            p->one->mode != p->two->mode)
3919                                return 0;
3920                        break;
3921                }
3922        }
3923        return 1;
3924}
3925
3926void diff_flush(struct diff_options *options)
3927{
3928        struct diff_queue_struct *q = &diff_queued_diff;
3929        int i, output_format = options->output_format;
3930        int separator = 0;
3931
3932        /*
3933         * Order: raw, stat, summary, patch
3934         * or:    name/name-status/checkdiff (other bits clear)
3935         */
3936        if (!q->nr)
3937                goto free_queue;
3938
3939        if (output_format & (DIFF_FORMAT_RAW |
3940                             DIFF_FORMAT_NAME |
3941                             DIFF_FORMAT_NAME_STATUS |
3942                             DIFF_FORMAT_CHECKDIFF)) {
3943                for (i = 0; i < q->nr; i++) {
3944                        struct diff_filepair *p = q->queue[i];
3945                        if (check_pair_status(p))
3946                                flush_one_pair(p, options);
3947                }
3948                separator++;
3949        }
3950
3951        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3952                struct diffstat_t diffstat;
3953
3954                memset(&diffstat, 0, sizeof(struct diffstat_t));
3955                for (i = 0; i < q->nr; i++) {
3956                        struct diff_filepair *p = q->queue[i];
3957                        if (check_pair_status(p))
3958                                diff_flush_stat(p, options, &diffstat);
3959                }
3960                if (output_format & DIFF_FORMAT_NUMSTAT)
3961                        show_numstat(&diffstat, options);
3962                if (output_format & DIFF_FORMAT_DIFFSTAT)
3963                        show_stats(&diffstat, options);
3964                if (output_format & DIFF_FORMAT_SHORTSTAT)
3965                        show_shortstats(&diffstat, options);
3966                free_diffstat_info(&diffstat);
3967                separator++;
3968        }
3969        if (output_format & DIFF_FORMAT_DIRSTAT)
3970                show_dirstat(options);
3971
3972        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3973                for (i = 0; i < q->nr; i++) {
3974                        diff_summary(options, q->queue[i]);
3975                }
3976                separator++;
3977        }
3978
3979        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3980            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3981            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3982                /*
3983                 * run diff_flush_patch for the exit status. setting
3984                 * options->file to /dev/null should be safe, becaue we
3985                 * aren't supposed to produce any output anyway.
3986                 */
3987                if (options->close_file)
3988                        fclose(options->file);
3989                options->file = fopen("/dev/null", "w");
3990                if (!options->file)
3991                        die_errno("Could not open /dev/null");
3992                options->close_file = 1;
3993                for (i = 0; i < q->nr; i++) {
3994                        struct diff_filepair *p = q->queue[i];
3995                        if (check_pair_status(p))
3996                                diff_flush_patch(p, options);
3997                        if (options->found_changes)
3998                                break;
3999                }
4000        }
4001
4002        if (output_format & DIFF_FORMAT_PATCH) {
4003                if (separator) {
4004                        putc(options->line_termination, options->file);
4005                        if (options->stat_sep) {
4006                                /* attach patch instead of inline */
4007                                fputs(options->stat_sep, options->file);
4008                        }
4009                }
4010
4011                for (i = 0; i < q->nr; i++) {
4012                        struct diff_filepair *p = q->queue[i];
4013                        if (check_pair_status(p))
4014                                diff_flush_patch(p, options);
4015                }
4016        }
4017
4018        if (output_format & DIFF_FORMAT_CALLBACK)
4019                options->format_callback(q, options, options->format_callback_data);
4020
4021        for (i = 0; i < q->nr; i++)
4022                diff_free_filepair(q->queue[i]);
4023free_queue:
4024        free(q->queue);
4025        DIFF_QUEUE_CLEAR(q);
4026        if (options->close_file)
4027                fclose(options->file);
4028
4029        /*
4030         * Report the content-level differences with HAS_CHANGES;
4031         * diff_addremove/diff_change does not set the bit when
4032         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4033         */
4034        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4035                if (options->found_changes)
4036                        DIFF_OPT_SET(options, HAS_CHANGES);
4037                else
4038                        DIFF_OPT_CLR(options, HAS_CHANGES);
4039        }
4040}
4041
4042static void diffcore_apply_filter(const char *filter)
4043{
4044        int i;
4045        struct diff_queue_struct *q = &diff_queued_diff;
4046        struct diff_queue_struct outq;
4047        DIFF_QUEUE_CLEAR(&outq);
4048
4049        if (!filter)
4050                return;
4051
4052        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4053                int found;
4054                for (i = found = 0; !found && i < q->nr; i++) {
4055                        struct diff_filepair *p = q->queue[i];
4056                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4057                             ((p->score &&
4058                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4059                              (!p->score &&
4060                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4061                            ((p->status != DIFF_STATUS_MODIFIED) &&
4062                             strchr(filter, p->status)))
4063                                found++;
4064                }
4065                if (found)
4066                        return;
4067
4068                /* otherwise we will clear the whole queue
4069                 * by copying the empty outq at the end of this
4070                 * function, but first clear the current entries
4071                 * in the queue.
4072                 */
4073                for (i = 0; i < q->nr; i++)
4074                        diff_free_filepair(q->queue[i]);
4075        }
4076        else {
4077                /* Only the matching ones */
4078                for (i = 0; i < q->nr; i++) {
4079                        struct diff_filepair *p = q->queue[i];
4080
4081                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4082                             ((p->score &&
4083                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4084                              (!p->score &&
4085                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4086                            ((p->status != DIFF_STATUS_MODIFIED) &&
4087                             strchr(filter, p->status)))
4088                                diff_q(&outq, p);
4089                        else
4090                                diff_free_filepair(p);
4091                }
4092        }
4093        free(q->queue);
4094        *q = outq;
4095}
4096
4097/* Check whether two filespecs with the same mode and size are identical */
4098static int diff_filespec_is_identical(struct diff_filespec *one,
4099                                      struct diff_filespec *two)
4100{
4101        if (S_ISGITLINK(one->mode))
4102                return 0;
4103        if (diff_populate_filespec(one, 0))
4104                return 0;
4105        if (diff_populate_filespec(two, 0))
4106                return 0;
4107        return !memcmp(one->data, two->data, one->size);
4108}
4109
4110static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4111{
4112        int i;
4113        struct diff_queue_struct *q = &diff_queued_diff;
4114        struct diff_queue_struct outq;
4115        DIFF_QUEUE_CLEAR(&outq);
4116
4117        for (i = 0; i < q->nr; i++) {
4118                struct diff_filepair *p = q->queue[i];
4119
4120                /*
4121                 * 1. Entries that come from stat info dirtiness
4122                 *    always have both sides (iow, not create/delete),
4123                 *    one side of the object name is unknown, with
4124                 *    the same mode and size.  Keep the ones that
4125                 *    do not match these criteria.  They have real
4126                 *    differences.
4127                 *
4128                 * 2. At this point, the file is known to be modified,
4129                 *    with the same mode and size, and the object
4130                 *    name of one side is unknown.  Need to inspect
4131                 *    the identical contents.
4132                 */
4133                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4134                    !DIFF_FILE_VALID(p->two) ||
4135                    (p->one->sha1_valid && p->two->sha1_valid) ||
4136                    (p->one->mode != p->two->mode) ||
4137                    diff_populate_filespec(p->one, 1) ||
4138                    diff_populate_filespec(p->two, 1) ||
4139                    (p->one->size != p->two->size) ||
4140                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4141                        diff_q(&outq, p);
4142                else {
4143                        /*
4144                         * The caller can subtract 1 from skip_stat_unmatch
4145                         * to determine how many paths were dirty only
4146                         * due to stat info mismatch.
4147                         */
4148                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4149                                diffopt->skip_stat_unmatch++;
4150                        diff_free_filepair(p);
4151                }
4152        }
4153        free(q->queue);
4154        *q = outq;
4155}
4156
4157static int diffnamecmp(const void *a_, const void *b_)
4158{
4159        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4160        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4161        const char *name_a, *name_b;
4162
4163        name_a = a->one ? a->one->path : a->two->path;
4164        name_b = b->one ? b->one->path : b->two->path;
4165        return strcmp(name_a, name_b);
4166}
4167
4168void diffcore_fix_diff_index(struct diff_options *options)
4169{
4170        struct diff_queue_struct *q = &diff_queued_diff;
4171        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4172}
4173
4174void diffcore_std(struct diff_options *options)
4175{
4176        if (options->skip_stat_unmatch)
4177                diffcore_skip_stat_unmatch(options);
4178        if (!options->found_follow) {
4179                /* See try_to_follow_renames() in tree-diff.c */
4180                if (options->break_opt != -1)
4181                        diffcore_break(options->break_opt);
4182                if (options->detect_rename)
4183                        diffcore_rename(options);
4184                if (options->break_opt != -1)
4185                        diffcore_merge_broken();
4186        }
4187        if (options->pickaxe)
4188                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
4189        if (options->orderfile)
4190                diffcore_order(options->orderfile);
4191        if (!options->found_follow)
4192                /* See try_to_follow_renames() in tree-diff.c */
4193                diff_resolve_rename_copy();
4194        diffcore_apply_filter(options->filter);
4195
4196        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4197                DIFF_OPT_SET(options, HAS_CHANGES);
4198        else
4199                DIFF_OPT_CLR(options, HAS_CHANGES);
4200
4201        options->found_follow = 0;
4202}
4203
4204int diff_result_code(struct diff_options *opt, int status)
4205{
4206        int result = 0;
4207        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4208            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4209                return status;
4210        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4211            DIFF_OPT_TST(opt, HAS_CHANGES))
4212                result |= 01;
4213        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4214            DIFF_OPT_TST(opt, CHECK_FAILED))
4215                result |= 02;
4216        return result;
4217}
4218
4219/*
4220 * Shall changes to this submodule be ignored?
4221 *
4222 * Submodule changes can be configured to be ignored separately for each path,
4223 * but that configuration can be overridden from the command line.
4224 */
4225static int is_submodule_ignored(const char *path, struct diff_options *options)
4226{
4227        int ignored = 0;
4228        unsigned orig_flags = options->flags;
4229        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4230                set_diffopt_flags_from_submodule_config(options, path);
4231        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4232                ignored = 1;
4233        options->flags = orig_flags;
4234        return ignored;
4235}
4236
4237void diff_addremove(struct diff_options *options,
4238                    int addremove, unsigned mode,
4239                    const unsigned char *sha1,
4240                    const char *concatpath, unsigned dirty_submodule)
4241{
4242        struct diff_filespec *one, *two;
4243
4244        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4245                return;
4246
4247        /* This may look odd, but it is a preparation for
4248         * feeding "there are unchanged files which should
4249         * not produce diffs, but when you are doing copy
4250         * detection you would need them, so here they are"
4251         * entries to the diff-core.  They will be prefixed
4252         * with something like '=' or '*' (I haven't decided
4253         * which but should not make any difference).
4254         * Feeding the same new and old to diff_change()
4255         * also has the same effect.
4256         * Before the final output happens, they are pruned after
4257         * merged into rename/copy pairs as appropriate.
4258         */
4259        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4260                addremove = (addremove == '+' ? '-' :
4261                             addremove == '-' ? '+' : addremove);
4262
4263        if (options->prefix &&
4264            strncmp(concatpath, options->prefix, options->prefix_length))
4265                return;
4266
4267        one = alloc_filespec(concatpath);
4268        two = alloc_filespec(concatpath);
4269
4270        if (addremove != '+')
4271                fill_filespec(one, sha1, mode);
4272        if (addremove != '-') {
4273                fill_filespec(two, sha1, mode);
4274                two->dirty_submodule = dirty_submodule;
4275        }
4276
4277        diff_queue(&diff_queued_diff, one, two);
4278        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4279                DIFF_OPT_SET(options, HAS_CHANGES);
4280}
4281
4282void diff_change(struct diff_options *options,
4283                 unsigned old_mode, unsigned new_mode,
4284                 const unsigned char *old_sha1,
4285                 const unsigned char *new_sha1,
4286                 const char *concatpath,
4287                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4288{
4289        struct diff_filespec *one, *two;
4290
4291        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4292            is_submodule_ignored(concatpath, options))
4293                return;
4294
4295        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4296                unsigned tmp;
4297                const unsigned char *tmp_c;
4298                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4299                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4300                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4301                        new_dirty_submodule = tmp;
4302        }
4303
4304        if (options->prefix &&
4305            strncmp(concatpath, options->prefix, options->prefix_length))
4306                return;
4307
4308        one = alloc_filespec(concatpath);
4309        two = alloc_filespec(concatpath);
4310        fill_filespec(one, old_sha1, old_mode);
4311        fill_filespec(two, new_sha1, new_mode);
4312        one->dirty_submodule = old_dirty_submodule;
4313        two->dirty_submodule = new_dirty_submodule;
4314
4315        diff_queue(&diff_queued_diff, one, two);
4316        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4317                DIFF_OPT_SET(options, HAS_CHANGES);
4318}
4319
4320void diff_unmerge(struct diff_options *options,
4321                  const char *path,
4322                  unsigned mode, const unsigned char *sha1)
4323{
4324        struct diff_filespec *one, *two;
4325
4326        if (options->prefix &&
4327            strncmp(path, options->prefix, options->prefix_length))
4328                return;
4329
4330        one = alloc_filespec(path);
4331        two = alloc_filespec(path);
4332        fill_filespec(one, sha1, mode);
4333        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4334}
4335
4336static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4337                size_t *outsize)
4338{
4339        struct diff_tempfile *temp;
4340        const char *argv[3];
4341        const char **arg = argv;
4342        struct child_process child;
4343        struct strbuf buf = STRBUF_INIT;
4344        int err = 0;
4345
4346        temp = prepare_temp_file(spec->path, spec);
4347        *arg++ = pgm;
4348        *arg++ = temp->name;
4349        *arg = NULL;
4350
4351        memset(&child, 0, sizeof(child));
4352        child.use_shell = 1;
4353        child.argv = argv;
4354        child.out = -1;
4355        if (start_command(&child)) {
4356                remove_tempfile();
4357                return NULL;
4358        }
4359
4360        if (strbuf_read(&buf, child.out, 0) < 0)
4361                err = error("error reading from textconv command '%s'", pgm);
4362        close(child.out);
4363
4364        if (finish_command(&child) || err) {
4365                strbuf_release(&buf);
4366                remove_tempfile();
4367                return NULL;
4368        }
4369        remove_tempfile();
4370
4371        return strbuf_detach(&buf, outsize);
4372}
4373
4374size_t fill_textconv(struct userdiff_driver *driver,
4375                     struct diff_filespec *df,
4376                     char **outbuf)
4377{
4378        size_t size;
4379
4380        if (!driver || !driver->textconv) {
4381                if (!DIFF_FILE_VALID(df)) {
4382                        *outbuf = "";
4383                        return 0;
4384                }
4385                if (diff_populate_filespec(df, 0))
4386                        die("unable to read files to diff");
4387                *outbuf = df->data;
4388                return df->size;
4389        }
4390
4391        if (driver->textconv_cache) {
4392                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4393                                          &size);
4394                if (*outbuf)
4395                        return size;
4396        }
4397
4398        *outbuf = run_textconv(driver->textconv, df, &size);
4399        if (!*outbuf)
4400                die("unable to read files to diff");
4401
4402        if (driver->textconv_cache) {
4403                /* ignore errors, as we might be in a readonly repository */
4404                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4405                                size);
4406                /*
4407                 * we could save up changes and flush them all at the end,
4408                 * but we would need an extra call after all diffing is done.
4409                 * Since generating a cache entry is the slow path anyway,
4410                 * this extra overhead probably isn't a big deal.
4411                 */
4412                notes_cache_write(driver->textconv_cache);
4413        }
4414
4415        return size;
4416}