82789e30eb7091d9405635438b6c406aac4adb40
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 400;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static 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
 248/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 249static unsigned long diff_filespec_size(struct diff_filespec *one)
 250{
 251        if (!DIFF_FILE_VALID(one))
 252                return 0;
 253        diff_populate_filespec(one, 1);
 254        return one->size;
 255}
 256
 257static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 258{
 259        char *ptr = mf->ptr;
 260        long size = mf->size;
 261        int cnt = 0;
 262
 263        if (!size)
 264                return cnt;
 265        ptr += size - 1; /* pointing at the very end */
 266        if (*ptr != '\n')
 267                ; /* incomplete line */
 268        else
 269                ptr--; /* skip the last LF */
 270        while (mf->ptr < ptr) {
 271                char *prev_eol;
 272                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 273                        if (*prev_eol == '\n')
 274                                break;
 275                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 276                        break;
 277                cnt++;
 278                ptr = prev_eol - 1;
 279        }
 280        return cnt;
 281}
 282
 283static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 284                               struct emit_callback *ecbdata)
 285{
 286        int l1, l2, at;
 287        unsigned ws_rule = ecbdata->ws_rule;
 288        l1 = count_trailing_blank(mf1, ws_rule);
 289        l2 = count_trailing_blank(mf2, ws_rule);
 290        if (l2 <= l1) {
 291                ecbdata->blank_at_eof_in_preimage = 0;
 292                ecbdata->blank_at_eof_in_postimage = 0;
 293                return;
 294        }
 295        at = count_lines(mf1->ptr, mf1->size);
 296        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 297
 298        at = count_lines(mf2->ptr, mf2->size);
 299        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 300}
 301
 302static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 303                        int first, const char *line, int len)
 304{
 305        int has_trailing_newline, has_trailing_carriage_return;
 306        int nofirst;
 307        FILE *file = o->file;
 308
 309        if (o->output_prefix) {
 310                struct strbuf *msg = NULL;
 311                msg = o->output_prefix(o, o->output_prefix_data);
 312                assert(msg);
 313                fwrite(msg->buf, msg->len, 1, file);
 314        }
 315
 316        if (len == 0) {
 317                has_trailing_newline = (first == '\n');
 318                has_trailing_carriage_return = (!has_trailing_newline &&
 319                                                (first == '\r'));
 320                nofirst = has_trailing_newline || has_trailing_carriage_return;
 321        } else {
 322                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 323                if (has_trailing_newline)
 324                        len--;
 325                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 326                if (has_trailing_carriage_return)
 327                        len--;
 328                nofirst = 0;
 329        }
 330
 331        if (len || !nofirst) {
 332                fputs(set, file);
 333                if (!nofirst)
 334                        fputc(first, file);
 335                fwrite(line, len, 1, file);
 336                fputs(reset, file);
 337        }
 338        if (has_trailing_carriage_return)
 339                fputc('\r', file);
 340        if (has_trailing_newline)
 341                fputc('\n', file);
 342}
 343
 344static void emit_line(struct diff_options *o, const char *set, const char *reset,
 345                      const char *line, int len)
 346{
 347        emit_line_0(o, set, reset, line[0], line+1, len-1);
 348}
 349
 350static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 351{
 352        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 353              ecbdata->blank_at_eof_in_preimage &&
 354              ecbdata->blank_at_eof_in_postimage &&
 355              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 356              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 357                return 0;
 358        return ws_blank_line(line, len, ecbdata->ws_rule);
 359}
 360
 361static void emit_add_line(const char *reset,
 362                          struct emit_callback *ecbdata,
 363                          const char *line, int len)
 364{
 365        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 366        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 367
 368        if (!*ws)
 369                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 370        else if (new_blank_line_at_eof(ecbdata, line, len))
 371                /* Blank line at EOF - paint '+' as well */
 372                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 373        else {
 374                /* Emit just the prefix, then the rest. */
 375                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 376                ws_check_emit(line, len, ecbdata->ws_rule,
 377                              ecbdata->opt->file, set, reset, ws);
 378        }
 379}
 380
 381static void emit_hunk_header(struct emit_callback *ecbdata,
 382                             const char *line, int len)
 383{
 384        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 385        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 386        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 387        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 388        static const char atat[2] = { '@', '@' };
 389        const char *cp, *ep;
 390        struct strbuf msgbuf = STRBUF_INIT;
 391        int org_len = len;
 392        int i = 1;
 393
 394        /*
 395         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 396         * it always is at least 10 bytes long.
 397         */
 398        if (len < 10 ||
 399            memcmp(line, atat, 2) ||
 400            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 401                emit_line(ecbdata->opt, plain, reset, line, len);
 402                return;
 403        }
 404        ep += 2; /* skip over @@ */
 405
 406        /* The hunk header in fraginfo color */
 407        strbuf_add(&msgbuf, frag, strlen(frag));
 408        strbuf_add(&msgbuf, line, ep - line);
 409        strbuf_add(&msgbuf, reset, strlen(reset));
 410
 411        /*
 412         * trailing "\r\n"
 413         */
 414        for ( ; i < 3; i++)
 415                if (line[len - i] == '\r' || line[len - i] == '\n')
 416                        len--;
 417
 418        /* blank before the func header */
 419        for (cp = ep; ep - line < len; ep++)
 420                if (*ep != ' ' && *ep != '\t')
 421                        break;
 422        if (ep != cp) {
 423                strbuf_add(&msgbuf, plain, strlen(plain));
 424                strbuf_add(&msgbuf, cp, ep - cp);
 425                strbuf_add(&msgbuf, reset, strlen(reset));
 426        }
 427
 428        if (ep < line + len) {
 429                strbuf_add(&msgbuf, func, strlen(func));
 430                strbuf_add(&msgbuf, ep, line + len - ep);
 431                strbuf_add(&msgbuf, reset, strlen(reset));
 432        }
 433
 434        strbuf_add(&msgbuf, line + len, org_len - len);
 435        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 436        strbuf_release(&msgbuf);
 437}
 438
 439static struct diff_tempfile *claim_diff_tempfile(void) {
 440        int i;
 441        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 442                if (!diff_temp[i].name)
 443                        return diff_temp + i;
 444        die("BUG: diff is failing to clean up its tempfiles");
 445}
 446
 447static int remove_tempfile_installed;
 448
 449static void remove_tempfile(void)
 450{
 451        int i;
 452        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 453                if (diff_temp[i].name == diff_temp[i].tmp_path)
 454                        unlink_or_warn(diff_temp[i].name);
 455                diff_temp[i].name = NULL;
 456        }
 457}
 458
 459static void remove_tempfile_on_signal(int signo)
 460{
 461        remove_tempfile();
 462        sigchain_pop(signo);
 463        raise(signo);
 464}
 465
 466static void print_line_count(FILE *file, int count)
 467{
 468        switch (count) {
 469        case 0:
 470                fprintf(file, "0,0");
 471                break;
 472        case 1:
 473                fprintf(file, "1");
 474                break;
 475        default:
 476                fprintf(file, "1,%d", count);
 477                break;
 478        }
 479}
 480
 481static void emit_rewrite_lines(struct emit_callback *ecb,
 482                               int prefix, const char *data, int size)
 483{
 484        const char *endp = NULL;
 485        static const char *nneof = " No newline at end of file\n";
 486        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 487        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 488
 489        while (0 < size) {
 490                int len;
 491
 492                endp = memchr(data, '\n', size);
 493                len = endp ? (endp - data + 1) : size;
 494                if (prefix != '+') {
 495                        ecb->lno_in_preimage++;
 496                        emit_line_0(ecb->opt, old, reset, '-',
 497                                    data, len);
 498                } else {
 499                        ecb->lno_in_postimage++;
 500                        emit_add_line(reset, ecb, data, len);
 501                }
 502                size -= len;
 503                data += len;
 504        }
 505        if (!endp) {
 506                const char *plain = diff_get_color(ecb->color_diff,
 507                                                   DIFF_PLAIN);
 508                emit_line_0(ecb->opt, plain, reset, '\\',
 509                            nneof, strlen(nneof));
 510        }
 511}
 512
 513static void emit_rewrite_diff(const char *name_a,
 514                              const char *name_b,
 515                              struct diff_filespec *one,
 516                              struct diff_filespec *two,
 517                              struct userdiff_driver *textconv_one,
 518                              struct userdiff_driver *textconv_two,
 519                              struct diff_options *o)
 520{
 521        int lc_a, lc_b;
 522        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 523        const char *name_a_tab, *name_b_tab;
 524        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 525        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 526        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 527        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 528        const char *a_prefix, *b_prefix;
 529        char *data_one, *data_two;
 530        size_t size_one, size_two;
 531        struct emit_callback ecbdata;
 532        char *line_prefix = "";
 533        struct strbuf *msgbuf;
 534
 535        if (o && o->output_prefix) {
 536                msgbuf = o->output_prefix(o, o->output_prefix_data);
 537                line_prefix = msgbuf->buf;
 538        }
 539
 540        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 541                a_prefix = o->b_prefix;
 542                b_prefix = o->a_prefix;
 543        } else {
 544                a_prefix = o->a_prefix;
 545                b_prefix = o->b_prefix;
 546        }
 547
 548        name_a += (*name_a == '/');
 549        name_b += (*name_b == '/');
 550        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 551        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 552
 553        strbuf_reset(&a_name);
 554        strbuf_reset(&b_name);
 555        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 556        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 557
 558        size_one = fill_textconv(textconv_one, one, &data_one);
 559        size_two = fill_textconv(textconv_two, two, &data_two);
 560
 561        memset(&ecbdata, 0, sizeof(ecbdata));
 562        ecbdata.color_diff = color_diff;
 563        ecbdata.found_changesp = &o->found_changes;
 564        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 565        ecbdata.opt = o;
 566        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 567                mmfile_t mf1, mf2;
 568                mf1.ptr = (char *)data_one;
 569                mf2.ptr = (char *)data_two;
 570                mf1.size = size_one;
 571                mf2.size = size_two;
 572                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 573        }
 574        ecbdata.lno_in_preimage = 1;
 575        ecbdata.lno_in_postimage = 1;
 576
 577        lc_a = count_lines(data_one, size_one);
 578        lc_b = count_lines(data_two, size_two);
 579        fprintf(o->file,
 580                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 581                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 582                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 583                line_prefix, fraginfo);
 584        if (!o->irreversible_delete)
 585                print_line_count(o->file, lc_a);
 586        else
 587                fprintf(o->file, "?,?");
 588        fprintf(o->file, " +");
 589        print_line_count(o->file, lc_b);
 590        fprintf(o->file, " @@%s\n", reset);
 591        if (lc_a && !o->irreversible_delete)
 592                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 593        if (lc_b)
 594                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 595        if (textconv_one)
 596                free((char *)data_one);
 597        if (textconv_two)
 598                free((char *)data_two);
 599}
 600
 601struct diff_words_buffer {
 602        mmfile_t text;
 603        long alloc;
 604        struct diff_words_orig {
 605                const char *begin, *end;
 606        } *orig;
 607        int orig_nr, orig_alloc;
 608};
 609
 610static void diff_words_append(char *line, unsigned long len,
 611                struct diff_words_buffer *buffer)
 612{
 613        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 614        line++;
 615        len--;
 616        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 617        buffer->text.size += len;
 618        buffer->text.ptr[buffer->text.size] = '\0';
 619}
 620
 621struct diff_words_style_elem {
 622        const char *prefix;
 623        const char *suffix;
 624        const char *color; /* NULL; filled in by the setup code if
 625                            * color is enabled */
 626};
 627
 628struct diff_words_style {
 629        enum diff_words_type type;
 630        struct diff_words_style_elem new, old, ctx;
 631        const char *newline;
 632};
 633
 634static struct diff_words_style diff_words_styles[] = {
 635        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 636        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 637        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 638};
 639
 640struct diff_words_data {
 641        struct diff_words_buffer minus, plus;
 642        const char *current_plus;
 643        int last_minus;
 644        struct diff_options *opt;
 645        regex_t *word_regex;
 646        enum diff_words_type type;
 647        struct diff_words_style *style;
 648};
 649
 650static int fn_out_diff_words_write_helper(FILE *fp,
 651                                          struct diff_words_style_elem *st_el,
 652                                          const char *newline,
 653                                          size_t count, const char *buf,
 654                                          const char *line_prefix)
 655{
 656        int print = 0;
 657
 658        while (count) {
 659                char *p = memchr(buf, '\n', count);
 660                if (print)
 661                        fputs(line_prefix, fp);
 662                if (p != buf) {
 663                        if (st_el->color && fputs(st_el->color, fp) < 0)
 664                                return -1;
 665                        if (fputs(st_el->prefix, fp) < 0 ||
 666                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 667                            fputs(st_el->suffix, fp) < 0)
 668                                return -1;
 669                        if (st_el->color && *st_el->color
 670                            && fputs(GIT_COLOR_RESET, fp) < 0)
 671                                return -1;
 672                }
 673                if (!p)
 674                        return 0;
 675                if (fputs(newline, fp) < 0)
 676                        return -1;
 677                count -= p + 1 - buf;
 678                buf = p + 1;
 679                print = 1;
 680        }
 681        return 0;
 682}
 683
 684/*
 685 * '--color-words' algorithm can be described as:
 686 *
 687 *   1. collect a the minus/plus lines of a diff hunk, divided into
 688 *      minus-lines and plus-lines;
 689 *
 690 *   2. break both minus-lines and plus-lines into words and
 691 *      place them into two mmfile_t with one word for each line;
 692 *
 693 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 694 *
 695 * And for the common parts of the both file, we output the plus side text.
 696 * diff_words->current_plus is used to trace the current position of the plus file
 697 * which printed. diff_words->last_minus is used to trace the last minus word
 698 * printed.
 699 *
 700 * For '--graph' to work with '--color-words', we need to output the graph prefix
 701 * on each line of color words output. Generally, there are two conditions on
 702 * which we should output the prefix.
 703 *
 704 *   1. diff_words->last_minus == 0 &&
 705 *      diff_words->current_plus == diff_words->plus.text.ptr
 706 *
 707 *      that is: the plus text must start as a new line, and if there is no minus
 708 *      word printed, a graph prefix must be printed.
 709 *
 710 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 711 *      *(diff_words->current_plus - 1) == '\n'
 712 *
 713 *      that is: a graph prefix must be printed following a '\n'
 714 */
 715static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 716{
 717        if ((diff_words->last_minus == 0 &&
 718                diff_words->current_plus == diff_words->plus.text.ptr) ||
 719                (diff_words->current_plus > diff_words->plus.text.ptr &&
 720                *(diff_words->current_plus - 1) == '\n')) {
 721                return 1;
 722        } else {
 723                return 0;
 724        }
 725}
 726
 727static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 728{
 729        struct diff_words_data *diff_words = priv;
 730        struct diff_words_style *style = diff_words->style;
 731        int minus_first, minus_len, plus_first, plus_len;
 732        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 733        struct diff_options *opt = diff_words->opt;
 734        struct strbuf *msgbuf;
 735        char *line_prefix = "";
 736
 737        if (line[0] != '@' || parse_hunk_header(line, len,
 738                        &minus_first, &minus_len, &plus_first, &plus_len))
 739                return;
 740
 741        assert(opt);
 742        if (opt->output_prefix) {
 743                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 744                line_prefix = msgbuf->buf;
 745        }
 746
 747        /* POSIX requires that first be decremented by one if len == 0... */
 748        if (minus_len) {
 749                minus_begin = diff_words->minus.orig[minus_first].begin;
 750                minus_end =
 751                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 752        } else
 753                minus_begin = minus_end =
 754                        diff_words->minus.orig[minus_first].end;
 755
 756        if (plus_len) {
 757                plus_begin = diff_words->plus.orig[plus_first].begin;
 758                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 759        } else
 760                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 761
 762        if (color_words_output_graph_prefix(diff_words)) {
 763                fputs(line_prefix, diff_words->opt->file);
 764        }
 765        if (diff_words->current_plus != plus_begin) {
 766                fn_out_diff_words_write_helper(diff_words->opt->file,
 767                                &style->ctx, style->newline,
 768                                plus_begin - diff_words->current_plus,
 769                                diff_words->current_plus, line_prefix);
 770                if (*(plus_begin - 1) == '\n')
 771                        fputs(line_prefix, diff_words->opt->file);
 772        }
 773        if (minus_begin != minus_end) {
 774                fn_out_diff_words_write_helper(diff_words->opt->file,
 775                                &style->old, style->newline,
 776                                minus_end - minus_begin, minus_begin,
 777                                line_prefix);
 778        }
 779        if (plus_begin != plus_end) {
 780                fn_out_diff_words_write_helper(diff_words->opt->file,
 781                                &style->new, style->newline,
 782                                plus_end - plus_begin, plus_begin,
 783                                line_prefix);
 784        }
 785
 786        diff_words->current_plus = plus_end;
 787        diff_words->last_minus = minus_first;
 788}
 789
 790/* This function starts looking at *begin, and returns 0 iff a word was found. */
 791static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 792                int *begin, int *end)
 793{
 794        if (word_regex && *begin < buffer->size) {
 795                regmatch_t match[1];
 796                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 797                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 798                                        '\n', match[0].rm_eo - match[0].rm_so);
 799                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 800                        *begin += match[0].rm_so;
 801                        return *begin >= *end;
 802                }
 803                return -1;
 804        }
 805
 806        /* find the next word */
 807        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 808                (*begin)++;
 809        if (*begin >= buffer->size)
 810                return -1;
 811
 812        /* find the end of the word */
 813        *end = *begin + 1;
 814        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 815                (*end)++;
 816
 817        return 0;
 818}
 819
 820/*
 821 * This function splits the words in buffer->text, stores the list with
 822 * newline separator into out, and saves the offsets of the original words
 823 * in buffer->orig.
 824 */
 825static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 826                regex_t *word_regex)
 827{
 828        int i, j;
 829        long alloc = 0;
 830
 831        out->size = 0;
 832        out->ptr = NULL;
 833
 834        /* fake an empty "0th" word */
 835        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 836        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 837        buffer->orig_nr = 1;
 838
 839        for (i = 0; i < buffer->text.size; i++) {
 840                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 841                        return;
 842
 843                /* store original boundaries */
 844                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 845                                buffer->orig_alloc);
 846                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 847                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 848                buffer->orig_nr++;
 849
 850                /* store one word */
 851                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 852                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 853                out->ptr[out->size + j - i] = '\n';
 854                out->size += j - i + 1;
 855
 856                i = j - 1;
 857        }
 858}
 859
 860/* this executes the word diff on the accumulated buffers */
 861static void diff_words_show(struct diff_words_data *diff_words)
 862{
 863        xpparam_t xpp;
 864        xdemitconf_t xecfg;
 865        mmfile_t minus, plus;
 866        struct diff_words_style *style = diff_words->style;
 867
 868        struct diff_options *opt = diff_words->opt;
 869        struct strbuf *msgbuf;
 870        char *line_prefix = "";
 871
 872        assert(opt);
 873        if (opt->output_prefix) {
 874                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 875                line_prefix = msgbuf->buf;
 876        }
 877
 878        /* special case: only removal */
 879        if (!diff_words->plus.text.size) {
 880                fputs(line_prefix, diff_words->opt->file);
 881                fn_out_diff_words_write_helper(diff_words->opt->file,
 882                        &style->old, style->newline,
 883                        diff_words->minus.text.size,
 884                        diff_words->minus.text.ptr, line_prefix);
 885                diff_words->minus.text.size = 0;
 886                return;
 887        }
 888
 889        diff_words->current_plus = diff_words->plus.text.ptr;
 890        diff_words->last_minus = 0;
 891
 892        memset(&xpp, 0, sizeof(xpp));
 893        memset(&xecfg, 0, sizeof(xecfg));
 894        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 895        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 896        xpp.flags = 0;
 897        /* as only the hunk header will be parsed, we need a 0-context */
 898        xecfg.ctxlen = 0;
 899        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 900                      &xpp, &xecfg);
 901        free(minus.ptr);
 902        free(plus.ptr);
 903        if (diff_words->current_plus != diff_words->plus.text.ptr +
 904                        diff_words->plus.text.size) {
 905                if (color_words_output_graph_prefix(diff_words))
 906                        fputs(line_prefix, diff_words->opt->file);
 907                fn_out_diff_words_write_helper(diff_words->opt->file,
 908                        &style->ctx, style->newline,
 909                        diff_words->plus.text.ptr + diff_words->plus.text.size
 910                        - diff_words->current_plus, diff_words->current_plus,
 911                        line_prefix);
 912        }
 913        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 914}
 915
 916/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 917static void diff_words_flush(struct emit_callback *ecbdata)
 918{
 919        if (ecbdata->diff_words->minus.text.size ||
 920            ecbdata->diff_words->plus.text.size)
 921                diff_words_show(ecbdata->diff_words);
 922}
 923
 924static void free_diff_words_data(struct emit_callback *ecbdata)
 925{
 926        if (ecbdata->diff_words) {
 927                diff_words_flush(ecbdata);
 928                free (ecbdata->diff_words->minus.text.ptr);
 929                free (ecbdata->diff_words->minus.orig);
 930                free (ecbdata->diff_words->plus.text.ptr);
 931                free (ecbdata->diff_words->plus.orig);
 932                if (ecbdata->diff_words->word_regex) {
 933                        regfree(ecbdata->diff_words->word_regex);
 934                        free(ecbdata->diff_words->word_regex);
 935                }
 936                free(ecbdata->diff_words);
 937                ecbdata->diff_words = NULL;
 938        }
 939}
 940
 941const char *diff_get_color(int diff_use_color, enum color_diff ix)
 942{
 943        if (diff_use_color)
 944                return diff_colors[ix];
 945        return "";
 946}
 947
 948static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 949{
 950        const char *cp;
 951        unsigned long allot;
 952        size_t l = len;
 953
 954        if (ecb->truncate)
 955                return ecb->truncate(line, len);
 956        cp = line;
 957        allot = l;
 958        while (0 < l) {
 959                (void) utf8_width(&cp, &l);
 960                if (!cp)
 961                        break; /* truncated in the middle? */
 962        }
 963        return allot - l;
 964}
 965
 966static void find_lno(const char *line, struct emit_callback *ecbdata)
 967{
 968        const char *p;
 969        ecbdata->lno_in_preimage = 0;
 970        ecbdata->lno_in_postimage = 0;
 971        p = strchr(line, '-');
 972        if (!p)
 973                return; /* cannot happen */
 974        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 975        p = strchr(p, '+');
 976        if (!p)
 977                return; /* cannot happen */
 978        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 979}
 980
 981static void fn_out_consume(void *priv, char *line, unsigned long len)
 982{
 983        struct emit_callback *ecbdata = priv;
 984        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 985        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 986        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 987        struct diff_options *o = ecbdata->opt;
 988        char *line_prefix = "";
 989        struct strbuf *msgbuf;
 990
 991        if (o && o->output_prefix) {
 992                msgbuf = o->output_prefix(o, o->output_prefix_data);
 993                line_prefix = msgbuf->buf;
 994        }
 995
 996        if (ecbdata->header) {
 997                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 998                strbuf_reset(ecbdata->header);
 999                ecbdata->header = NULL;
1000        }
1001        *(ecbdata->found_changesp) = 1;
1002
1003        if (ecbdata->label_path[0]) {
1004                const char *name_a_tab, *name_b_tab;
1005
1006                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1007                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1008
1009                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1010                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1011                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1012                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1013                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1014        }
1015
1016        if (diff_suppress_blank_empty
1017            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1018                line[0] = '\n';
1019                len = 1;
1020        }
1021
1022        if (line[0] == '@') {
1023                if (ecbdata->diff_words)
1024                        diff_words_flush(ecbdata);
1025                len = sane_truncate_line(ecbdata, line, len);
1026                find_lno(line, ecbdata);
1027                emit_hunk_header(ecbdata, line, len);
1028                if (line[len-1] != '\n')
1029                        putc('\n', ecbdata->opt->file);
1030                return;
1031        }
1032
1033        if (len < 1) {
1034                emit_line(ecbdata->opt, reset, reset, line, len);
1035                if (ecbdata->diff_words
1036                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1037                        fputs("~\n", ecbdata->opt->file);
1038                return;
1039        }
1040
1041        if (ecbdata->diff_words) {
1042                if (line[0] == '-') {
1043                        diff_words_append(line, len,
1044                                          &ecbdata->diff_words->minus);
1045                        return;
1046                } else if (line[0] == '+') {
1047                        diff_words_append(line, len,
1048                                          &ecbdata->diff_words->plus);
1049                        return;
1050                }
1051                diff_words_flush(ecbdata);
1052                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1053                        emit_line(ecbdata->opt, plain, reset, line, len);
1054                        fputs("~\n", ecbdata->opt->file);
1055                } else {
1056                        /* don't print the prefix character */
1057                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1058                }
1059                return;
1060        }
1061
1062        if (line[0] != '+') {
1063                const char *color =
1064                        diff_get_color(ecbdata->color_diff,
1065                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1066                ecbdata->lno_in_preimage++;
1067                if (line[0] == ' ')
1068                        ecbdata->lno_in_postimage++;
1069                emit_line(ecbdata->opt, color, reset, line, len);
1070        } else {
1071                ecbdata->lno_in_postimage++;
1072                emit_add_line(reset, ecbdata, line + 1, len - 1);
1073        }
1074}
1075
1076static char *pprint_rename(const char *a, const char *b)
1077{
1078        const char *old = a;
1079        const char *new = b;
1080        struct strbuf name = STRBUF_INIT;
1081        int pfx_length, sfx_length;
1082        int len_a = strlen(a);
1083        int len_b = strlen(b);
1084        int a_midlen, b_midlen;
1085        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1086        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1087
1088        if (qlen_a || qlen_b) {
1089                quote_c_style(a, &name, NULL, 0);
1090                strbuf_addstr(&name, " => ");
1091                quote_c_style(b, &name, NULL, 0);
1092                return strbuf_detach(&name, NULL);
1093        }
1094
1095        /* Find common prefix */
1096        pfx_length = 0;
1097        while (*old && *new && *old == *new) {
1098                if (*old == '/')
1099                        pfx_length = old - a + 1;
1100                old++;
1101                new++;
1102        }
1103
1104        /* Find common suffix */
1105        old = a + len_a;
1106        new = b + len_b;
1107        sfx_length = 0;
1108        while (a <= old && b <= new && *old == *new) {
1109                if (*old == '/')
1110                        sfx_length = len_a - (old - a);
1111                old--;
1112                new--;
1113        }
1114
1115        /*
1116         * pfx{mid-a => mid-b}sfx
1117         * {pfx-a => pfx-b}sfx
1118         * pfx{sfx-a => sfx-b}
1119         * name-a => name-b
1120         */
1121        a_midlen = len_a - pfx_length - sfx_length;
1122        b_midlen = len_b - pfx_length - sfx_length;
1123        if (a_midlen < 0)
1124                a_midlen = 0;
1125        if (b_midlen < 0)
1126                b_midlen = 0;
1127
1128        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1129        if (pfx_length + sfx_length) {
1130                strbuf_add(&name, a, pfx_length);
1131                strbuf_addch(&name, '{');
1132        }
1133        strbuf_add(&name, a + pfx_length, a_midlen);
1134        strbuf_addstr(&name, " => ");
1135        strbuf_add(&name, b + pfx_length, b_midlen);
1136        if (pfx_length + sfx_length) {
1137                strbuf_addch(&name, '}');
1138                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1139        }
1140        return strbuf_detach(&name, NULL);
1141}
1142
1143struct diffstat_t {
1144        int nr;
1145        int alloc;
1146        struct diffstat_file {
1147                char *from_name;
1148                char *name;
1149                char *print_name;
1150                unsigned is_unmerged:1;
1151                unsigned is_binary:1;
1152                unsigned is_renamed:1;
1153                uintmax_t added, deleted;
1154        } **files;
1155};
1156
1157static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1158                                          const char *name_a,
1159                                          const char *name_b)
1160{
1161        struct diffstat_file *x;
1162        x = xcalloc(sizeof (*x), 1);
1163        if (diffstat->nr == diffstat->alloc) {
1164                diffstat->alloc = alloc_nr(diffstat->alloc);
1165                diffstat->files = xrealloc(diffstat->files,
1166                                diffstat->alloc * sizeof(x));
1167        }
1168        diffstat->files[diffstat->nr++] = x;
1169        if (name_b) {
1170                x->from_name = xstrdup(name_a);
1171                x->name = xstrdup(name_b);
1172                x->is_renamed = 1;
1173        }
1174        else {
1175                x->from_name = NULL;
1176                x->name = xstrdup(name_a);
1177        }
1178        return x;
1179}
1180
1181static void diffstat_consume(void *priv, char *line, unsigned long len)
1182{
1183        struct diffstat_t *diffstat = priv;
1184        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1185
1186        if (line[0] == '+')
1187                x->added++;
1188        else if (line[0] == '-')
1189                x->deleted++;
1190}
1191
1192const char mime_boundary_leader[] = "------------";
1193
1194static int scale_linear(int it, int width, int max_change)
1195{
1196        /*
1197         * make sure that at least one '-' is printed if there were deletions,
1198         * and likewise for '+'.
1199         */
1200        if (max_change < 2)
1201                return it;
1202        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1203}
1204
1205static void show_name(FILE *file,
1206                      const char *prefix, const char *name, int len)
1207{
1208        fprintf(file, " %s%-*s |", prefix, len, name);
1209}
1210
1211static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1212{
1213        if (cnt <= 0)
1214                return;
1215        fprintf(file, "%s", set);
1216        while (cnt--)
1217                putc(ch, file);
1218        fprintf(file, "%s", reset);
1219}
1220
1221static void fill_print_name(struct diffstat_file *file)
1222{
1223        char *pname;
1224
1225        if (file->print_name)
1226                return;
1227
1228        if (!file->is_renamed) {
1229                struct strbuf buf = STRBUF_INIT;
1230                if (quote_c_style(file->name, &buf, NULL, 0)) {
1231                        pname = strbuf_detach(&buf, NULL);
1232                } else {
1233                        pname = file->name;
1234                        strbuf_release(&buf);
1235                }
1236        } else {
1237                pname = pprint_rename(file->from_name, file->name);
1238        }
1239        file->print_name = pname;
1240}
1241
1242static void show_stats(struct diffstat_t *data, struct diff_options *options)
1243{
1244        int i, len, add, del, adds = 0, dels = 0;
1245        uintmax_t max_change = 0, max_len = 0;
1246        int total_files = data->nr;
1247        int width, name_width, count;
1248        const char *reset, *add_c, *del_c;
1249        const char *line_prefix = "";
1250        struct strbuf *msg = NULL;
1251
1252        if (data->nr == 0)
1253                return;
1254
1255        if (options->output_prefix) {
1256                msg = options->output_prefix(options, options->output_prefix_data);
1257                line_prefix = msg->buf;
1258        }
1259
1260        width = options->stat_width ? options->stat_width : 80;
1261        name_width = options->stat_name_width ? options->stat_name_width : 50;
1262        count = options->stat_count ? options->stat_count : data->nr;
1263
1264        /* Sanity: give at least 5 columns to the graph,
1265         * but leave at least 10 columns for the name.
1266         */
1267        if (width < 25)
1268                width = 25;
1269        if (name_width < 10)
1270                name_width = 10;
1271        else if (width < name_width + 15)
1272                name_width = width - 15;
1273
1274        /* Find the longest filename and max number of changes */
1275        reset = diff_get_color_opt(options, DIFF_RESET);
1276        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1277        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1278
1279        for (i = 0; (i < count) && (i < data->nr); i++) {
1280                struct diffstat_file *file = data->files[i];
1281                uintmax_t change = file->added + file->deleted;
1282                if (!data->files[i]->is_renamed &&
1283                         (change == 0)) {
1284                        count++; /* not shown == room for one more */
1285                        continue;
1286                }
1287                fill_print_name(file);
1288                len = strlen(file->print_name);
1289                if (max_len < len)
1290                        max_len = len;
1291
1292                if (file->is_binary || file->is_unmerged)
1293                        continue;
1294                if (max_change < change)
1295                        max_change = change;
1296        }
1297        count = i; /* min(count, data->nr) */
1298
1299        /* Compute the width of the graph part;
1300         * 10 is for one blank at the beginning of the line plus
1301         * " | count " between the name and the graph.
1302         *
1303         * From here on, name_width is the width of the name area,
1304         * and width is the width of the graph area.
1305         */
1306        name_width = (name_width < max_len) ? name_width : max_len;
1307        if (width < (name_width + 10) + max_change)
1308                width = width - (name_width + 10);
1309        else
1310                width = max_change;
1311
1312        for (i = 0; i < count; i++) {
1313                const char *prefix = "";
1314                char *name = data->files[i]->print_name;
1315                uintmax_t added = data->files[i]->added;
1316                uintmax_t deleted = data->files[i]->deleted;
1317                int name_len;
1318
1319                if (!data->files[i]->is_renamed &&
1320                         (added + deleted == 0)) {
1321                        total_files--;
1322                        continue;
1323                }
1324                /*
1325                 * "scale" the filename
1326                 */
1327                len = name_width;
1328                name_len = strlen(name);
1329                if (name_width < name_len) {
1330                        char *slash;
1331                        prefix = "...";
1332                        len -= 3;
1333                        name += name_len - len;
1334                        slash = strchr(name, '/');
1335                        if (slash)
1336                                name = slash;
1337                }
1338
1339                if (data->files[i]->is_binary) {
1340                        fprintf(options->file, "%s", line_prefix);
1341                        show_name(options->file, prefix, name, len);
1342                        fprintf(options->file, "  Bin ");
1343                        fprintf(options->file, "%s%"PRIuMAX"%s",
1344                                del_c, deleted, reset);
1345                        fprintf(options->file, " -> ");
1346                        fprintf(options->file, "%s%"PRIuMAX"%s",
1347                                add_c, added, reset);
1348                        fprintf(options->file, " bytes");
1349                        fprintf(options->file, "\n");
1350                        continue;
1351                }
1352                else if (data->files[i]->is_unmerged) {
1353                        fprintf(options->file, "%s", line_prefix);
1354                        show_name(options->file, prefix, name, len);
1355                        fprintf(options->file, "  Unmerged\n");
1356                        continue;
1357                }
1358
1359                /*
1360                 * scale the add/delete
1361                 */
1362                add = added;
1363                del = deleted;
1364                adds += add;
1365                dels += del;
1366
1367                if (width <= max_change) {
1368                        add = scale_linear(add, width, max_change);
1369                        del = scale_linear(del, width, max_change);
1370                }
1371                fprintf(options->file, "%s", line_prefix);
1372                show_name(options->file, prefix, name, len);
1373                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1374                                added + deleted ? " " : "");
1375                show_graph(options->file, '+', add, add_c, reset);
1376                show_graph(options->file, '-', del, del_c, reset);
1377                fprintf(options->file, "\n");
1378        }
1379        if (count < data->nr)
1380                fprintf(options->file, "%s ...\n", line_prefix);
1381        for (i = count; i < data->nr; i++) {
1382                uintmax_t added = data->files[i]->added;
1383                uintmax_t deleted = data->files[i]->deleted;
1384                if (!data->files[i]->is_renamed &&
1385                         (added + deleted == 0)) {
1386                        total_files--;
1387                        continue;
1388                }
1389                adds += added;
1390                dels += deleted;
1391        }
1392        fprintf(options->file, "%s", line_prefix);
1393        fprintf(options->file,
1394               " %d files changed, %d insertions(+), %d deletions(-)\n",
1395               total_files, adds, dels);
1396}
1397
1398static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1399{
1400        int i, adds = 0, dels = 0, total_files = data->nr;
1401
1402        if (data->nr == 0)
1403                return;
1404
1405        for (i = 0; i < data->nr; i++) {
1406                if (!data->files[i]->is_binary &&
1407                    !data->files[i]->is_unmerged) {
1408                        int added = data->files[i]->added;
1409                        int deleted= data->files[i]->deleted;
1410                        if (!data->files[i]->is_renamed &&
1411                            (added + deleted == 0)) {
1412                                total_files--;
1413                        } else {
1414                                adds += added;
1415                                dels += deleted;
1416                        }
1417                }
1418        }
1419        if (options->output_prefix) {
1420                struct strbuf *msg = NULL;
1421                msg = options->output_prefix(options,
1422                                options->output_prefix_data);
1423                fprintf(options->file, "%s", msg->buf);
1424        }
1425        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1426               total_files, adds, dels);
1427}
1428
1429static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1430{
1431        int i;
1432
1433        if (data->nr == 0)
1434                return;
1435
1436        for (i = 0; i < data->nr; i++) {
1437                struct diffstat_file *file = data->files[i];
1438
1439                if (options->output_prefix) {
1440                        struct strbuf *msg = NULL;
1441                        msg = options->output_prefix(options,
1442                                        options->output_prefix_data);
1443                        fprintf(options->file, "%s", msg->buf);
1444                }
1445
1446                if (file->is_binary)
1447                        fprintf(options->file, "-\t-\t");
1448                else
1449                        fprintf(options->file,
1450                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1451                                file->added, file->deleted);
1452                if (options->line_termination) {
1453                        fill_print_name(file);
1454                        if (!file->is_renamed)
1455                                write_name_quoted(file->name, options->file,
1456                                                  options->line_termination);
1457                        else {
1458                                fputs(file->print_name, options->file);
1459                                putc(options->line_termination, options->file);
1460                        }
1461                } else {
1462                        if (file->is_renamed) {
1463                                putc('\0', options->file);
1464                                write_name_quoted(file->from_name, options->file, '\0');
1465                        }
1466                        write_name_quoted(file->name, options->file, '\0');
1467                }
1468        }
1469}
1470
1471struct dirstat_file {
1472        const char *name;
1473        unsigned long changed;
1474};
1475
1476struct dirstat_dir {
1477        struct dirstat_file *files;
1478        int alloc, nr, percent, cumulative;
1479};
1480
1481static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1482                unsigned long changed, const char *base, int baselen)
1483{
1484        unsigned long this_dir = 0;
1485        unsigned int sources = 0;
1486        const char *line_prefix = "";
1487        struct strbuf *msg = NULL;
1488
1489        if (opt->output_prefix) {
1490                msg = opt->output_prefix(opt, opt->output_prefix_data);
1491                line_prefix = msg->buf;
1492        }
1493
1494        while (dir->nr) {
1495                struct dirstat_file *f = dir->files;
1496                int namelen = strlen(f->name);
1497                unsigned long this;
1498                char *slash;
1499
1500                if (namelen < baselen)
1501                        break;
1502                if (memcmp(f->name, base, baselen))
1503                        break;
1504                slash = strchr(f->name + baselen, '/');
1505                if (slash) {
1506                        int newbaselen = slash + 1 - f->name;
1507                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1508                        sources++;
1509                } else {
1510                        this = f->changed;
1511                        dir->files++;
1512                        dir->nr--;
1513                        sources += 2;
1514                }
1515                this_dir += this;
1516        }
1517
1518        /*
1519         * We don't report dirstat's for
1520         *  - the top level
1521         *  - or cases where everything came from a single directory
1522         *    under this directory (sources == 1).
1523         */
1524        if (baselen && sources != 1) {
1525                int permille = this_dir * 1000 / changed;
1526                if (permille) {
1527                        int percent = permille / 10;
1528                        if (percent >= dir->percent) {
1529                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1530                                        percent, permille % 10, baselen, base);
1531                                if (!dir->cumulative)
1532                                        return 0;
1533                        }
1534                }
1535        }
1536        return this_dir;
1537}
1538
1539static int dirstat_compare(const void *_a, const void *_b)
1540{
1541        const struct dirstat_file *a = _a;
1542        const struct dirstat_file *b = _b;
1543        return strcmp(a->name, b->name);
1544}
1545
1546static void show_dirstat(struct diff_options *options)
1547{
1548        int i;
1549        unsigned long changed;
1550        struct dirstat_dir dir;
1551        struct diff_queue_struct *q = &diff_queued_diff;
1552
1553        dir.files = NULL;
1554        dir.alloc = 0;
1555        dir.nr = 0;
1556        dir.percent = options->dirstat_percent;
1557        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1558
1559        changed = 0;
1560        for (i = 0; i < q->nr; i++) {
1561                struct diff_filepair *p = q->queue[i];
1562                const char *name;
1563                unsigned long copied, added, damage;
1564                int content_changed;
1565
1566                name = p->two->path ? p->two->path : p->one->path;
1567
1568                if (p->one->sha1_valid && p->two->sha1_valid)
1569                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1570                else
1571                        content_changed = 1;
1572
1573                if (!content_changed) {
1574                        /*
1575                         * The SHA1 has not changed, so pre-/post-content is
1576                         * identical. We can therefore skip looking at the
1577                         * file contents altogether.
1578                         */
1579                        damage = 0;
1580                        goto found_damage;
1581                }
1582
1583                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1584                        /*
1585                         * In --dirstat-by-file mode, we don't really need to
1586                         * look at the actual file contents at all.
1587                         * The fact that the SHA1 changed is enough for us to
1588                         * add this file to the list of results
1589                         * (with each file contributing equal damage).
1590                         */
1591                        damage = 1;
1592                        goto found_damage;
1593                }
1594
1595                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1596                        diff_populate_filespec(p->one, 0);
1597                        diff_populate_filespec(p->two, 0);
1598                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1599                                               &copied, &added);
1600                        diff_free_filespec_data(p->one);
1601                        diff_free_filespec_data(p->two);
1602                } else if (DIFF_FILE_VALID(p->one)) {
1603                        diff_populate_filespec(p->one, 1);
1604                        copied = added = 0;
1605                        diff_free_filespec_data(p->one);
1606                } else if (DIFF_FILE_VALID(p->two)) {
1607                        diff_populate_filespec(p->two, 1);
1608                        copied = 0;
1609                        added = p->two->size;
1610                        diff_free_filespec_data(p->two);
1611                } else
1612                        continue;
1613
1614                /*
1615                 * Original minus copied is the removed material,
1616                 * added is the new material.  They are both damages
1617                 * made to the preimage.
1618                 * If the resulting damage is zero, we know that
1619                 * diffcore_count_changes() considers the two entries to
1620                 * be identical, but since content_changed is true, we
1621                 * know that there must have been _some_ kind of change,
1622                 * so we force all entries to have damage > 0.
1623                 */
1624                damage = (p->one->size - copied) + added;
1625                if (!damage)
1626                        damage = 1;
1627
1628found_damage:
1629                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1630                dir.files[dir.nr].name = name;
1631                dir.files[dir.nr].changed = damage;
1632                changed += damage;
1633                dir.nr++;
1634        }
1635
1636        /* This can happen even with many files, if everything was renames */
1637        if (!changed)
1638                return;
1639
1640        /* Show all directories with more than x% of the changes */
1641        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1642        gather_dirstat(options, &dir, changed, "", 0);
1643}
1644
1645static void free_diffstat_info(struct diffstat_t *diffstat)
1646{
1647        int i;
1648        for (i = 0; i < diffstat->nr; i++) {
1649                struct diffstat_file *f = diffstat->files[i];
1650                if (f->name != f->print_name)
1651                        free(f->print_name);
1652                free(f->name);
1653                free(f->from_name);
1654                free(f);
1655        }
1656        free(diffstat->files);
1657}
1658
1659struct checkdiff_t {
1660        const char *filename;
1661        int lineno;
1662        int conflict_marker_size;
1663        struct diff_options *o;
1664        unsigned ws_rule;
1665        unsigned status;
1666};
1667
1668static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1669{
1670        char firstchar;
1671        int cnt;
1672
1673        if (len < marker_size + 1)
1674                return 0;
1675        firstchar = line[0];
1676        switch (firstchar) {
1677        case '=': case '>': case '<': case '|':
1678                break;
1679        default:
1680                return 0;
1681        }
1682        for (cnt = 1; cnt < marker_size; cnt++)
1683                if (line[cnt] != firstchar)
1684                        return 0;
1685        /* line[1] thru line[marker_size-1] are same as firstchar */
1686        if (len < marker_size + 1 || !isspace(line[marker_size]))
1687                return 0;
1688        return 1;
1689}
1690
1691static void checkdiff_consume(void *priv, char *line, unsigned long len)
1692{
1693        struct checkdiff_t *data = priv;
1694        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1695        int marker_size = data->conflict_marker_size;
1696        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1697        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1698        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1699        char *err;
1700        char *line_prefix = "";
1701        struct strbuf *msgbuf;
1702
1703        assert(data->o);
1704        if (data->o->output_prefix) {
1705                msgbuf = data->o->output_prefix(data->o,
1706                        data->o->output_prefix_data);
1707                line_prefix = msgbuf->buf;
1708        }
1709
1710        if (line[0] == '+') {
1711                unsigned bad;
1712                data->lineno++;
1713                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1714                        data->status |= 1;
1715                        fprintf(data->o->file,
1716                                "%s%s:%d: leftover conflict marker\n",
1717                                line_prefix, data->filename, data->lineno);
1718                }
1719                bad = ws_check(line + 1, len - 1, data->ws_rule);
1720                if (!bad)
1721                        return;
1722                data->status |= bad;
1723                err = whitespace_error_string(bad);
1724                fprintf(data->o->file, "%s%s:%d: %s.\n",
1725                        line_prefix, data->filename, data->lineno, err);
1726                free(err);
1727                emit_line(data->o, set, reset, line, 1);
1728                ws_check_emit(line + 1, len - 1, data->ws_rule,
1729                              data->o->file, set, reset, ws);
1730        } else if (line[0] == ' ') {
1731                data->lineno++;
1732        } else if (line[0] == '@') {
1733                char *plus = strchr(line, '+');
1734                if (plus)
1735                        data->lineno = strtol(plus, NULL, 10) - 1;
1736                else
1737                        die("invalid diff");
1738        }
1739}
1740
1741static unsigned char *deflate_it(char *data,
1742                                 unsigned long size,
1743                                 unsigned long *result_size)
1744{
1745        int bound;
1746        unsigned char *deflated;
1747        z_stream stream;
1748
1749        memset(&stream, 0, sizeof(stream));
1750        deflateInit(&stream, zlib_compression_level);
1751        bound = deflateBound(&stream, size);
1752        deflated = xmalloc(bound);
1753        stream.next_out = deflated;
1754        stream.avail_out = bound;
1755
1756        stream.next_in = (unsigned char *)data;
1757        stream.avail_in = size;
1758        while (deflate(&stream, Z_FINISH) == Z_OK)
1759                ; /* nothing */
1760        deflateEnd(&stream);
1761        *result_size = stream.total_out;
1762        return deflated;
1763}
1764
1765static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1766{
1767        void *cp;
1768        void *delta;
1769        void *deflated;
1770        void *data;
1771        unsigned long orig_size;
1772        unsigned long delta_size;
1773        unsigned long deflate_size;
1774        unsigned long data_size;
1775
1776        /* We could do deflated delta, or we could do just deflated two,
1777         * whichever is smaller.
1778         */
1779        delta = NULL;
1780        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1781        if (one->size && two->size) {
1782                delta = diff_delta(one->ptr, one->size,
1783                                   two->ptr, two->size,
1784                                   &delta_size, deflate_size);
1785                if (delta) {
1786                        void *to_free = delta;
1787                        orig_size = delta_size;
1788                        delta = deflate_it(delta, delta_size, &delta_size);
1789                        free(to_free);
1790                }
1791        }
1792
1793        if (delta && delta_size < deflate_size) {
1794                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1795                free(deflated);
1796                data = delta;
1797                data_size = delta_size;
1798        }
1799        else {
1800                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1801                free(delta);
1802                data = deflated;
1803                data_size = deflate_size;
1804        }
1805
1806        /* emit data encoded in base85 */
1807        cp = data;
1808        while (data_size) {
1809                int bytes = (52 < data_size) ? 52 : data_size;
1810                char line[70];
1811                data_size -= bytes;
1812                if (bytes <= 26)
1813                        line[0] = bytes + 'A' - 1;
1814                else
1815                        line[0] = bytes - 26 + 'a' - 1;
1816                encode_85(line + 1, cp, bytes);
1817                cp = (char *) cp + bytes;
1818                fprintf(file, "%s", prefix);
1819                fputs(line, file);
1820                fputc('\n', file);
1821        }
1822        fprintf(file, "%s\n", prefix);
1823        free(data);
1824}
1825
1826static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1827{
1828        fprintf(file, "%sGIT binary patch\n", prefix);
1829        emit_binary_diff_body(file, one, two, prefix);
1830        emit_binary_diff_body(file, two, one, prefix);
1831}
1832
1833static void diff_filespec_load_driver(struct diff_filespec *one)
1834{
1835        /* Use already-loaded driver */
1836        if (one->driver)
1837                return;
1838
1839        if (S_ISREG(one->mode))
1840                one->driver = userdiff_find_by_path(one->path);
1841
1842        /* Fallback to default settings */
1843        if (!one->driver)
1844                one->driver = userdiff_find_by_name("default");
1845}
1846
1847int diff_filespec_is_binary(struct diff_filespec *one)
1848{
1849        if (one->is_binary == -1) {
1850                diff_filespec_load_driver(one);
1851                if (one->driver->binary != -1)
1852                        one->is_binary = one->driver->binary;
1853                else {
1854                        if (!one->data && DIFF_FILE_VALID(one))
1855                                diff_populate_filespec(one, 0);
1856                        if (one->data)
1857                                one->is_binary = buffer_is_binary(one->data,
1858                                                one->size);
1859                        if (one->is_binary == -1)
1860                                one->is_binary = 0;
1861                }
1862        }
1863        return one->is_binary;
1864}
1865
1866static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1867{
1868        diff_filespec_load_driver(one);
1869        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1870}
1871
1872static const char *userdiff_word_regex(struct diff_filespec *one)
1873{
1874        diff_filespec_load_driver(one);
1875        return one->driver->word_regex;
1876}
1877
1878void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1879{
1880        if (!options->a_prefix)
1881                options->a_prefix = a;
1882        if (!options->b_prefix)
1883                options->b_prefix = b;
1884}
1885
1886struct userdiff_driver *get_textconv(struct diff_filespec *one)
1887{
1888        if (!DIFF_FILE_VALID(one))
1889                return NULL;
1890
1891        diff_filespec_load_driver(one);
1892        if (!one->driver->textconv)
1893                return NULL;
1894
1895        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1896                struct notes_cache *c = xmalloc(sizeof(*c));
1897                struct strbuf name = STRBUF_INIT;
1898
1899                strbuf_addf(&name, "textconv/%s", one->driver->name);
1900                notes_cache_init(c, name.buf, one->driver->textconv);
1901                one->driver->textconv_cache = c;
1902        }
1903
1904        return one->driver;
1905}
1906
1907static void builtin_diff(const char *name_a,
1908                         const char *name_b,
1909                         struct diff_filespec *one,
1910                         struct diff_filespec *two,
1911                         const char *xfrm_msg,
1912                         int must_show_header,
1913                         struct diff_options *o,
1914                         int complete_rewrite)
1915{
1916        mmfile_t mf1, mf2;
1917        const char *lbl[2];
1918        char *a_one, *b_two;
1919        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1920        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1921        const char *a_prefix, *b_prefix;
1922        struct userdiff_driver *textconv_one = NULL;
1923        struct userdiff_driver *textconv_two = NULL;
1924        struct strbuf header = STRBUF_INIT;
1925        struct strbuf *msgbuf;
1926        char *line_prefix = "";
1927
1928        if (o->output_prefix) {
1929                msgbuf = o->output_prefix(o, o->output_prefix_data);
1930                line_prefix = msgbuf->buf;
1931        }
1932
1933        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1934                        (!one->mode || S_ISGITLINK(one->mode)) &&
1935                        (!two->mode || S_ISGITLINK(two->mode))) {
1936                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1937                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1938                show_submodule_summary(o->file, one ? one->path : two->path,
1939                                one->sha1, two->sha1, two->dirty_submodule,
1940                                del, add, reset);
1941                return;
1942        }
1943
1944        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1945                textconv_one = get_textconv(one);
1946                textconv_two = get_textconv(two);
1947        }
1948
1949        diff_set_mnemonic_prefix(o, "a/", "b/");
1950        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1951                a_prefix = o->b_prefix;
1952                b_prefix = o->a_prefix;
1953        } else {
1954                a_prefix = o->a_prefix;
1955                b_prefix = o->b_prefix;
1956        }
1957
1958        /* Never use a non-valid filename anywhere if at all possible */
1959        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1960        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1961
1962        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1963        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1964        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1965        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1966        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1967        if (lbl[0][0] == '/') {
1968                /* /dev/null */
1969                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1970                if (xfrm_msg)
1971                        strbuf_addstr(&header, xfrm_msg);
1972                must_show_header = 1;
1973        }
1974        else if (lbl[1][0] == '/') {
1975                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1976                if (xfrm_msg)
1977                        strbuf_addstr(&header, xfrm_msg);
1978                must_show_header = 1;
1979        }
1980        else {
1981                if (one->mode != two->mode) {
1982                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1983                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1984                        must_show_header = 1;
1985                }
1986                if (xfrm_msg)
1987                        strbuf_addstr(&header, xfrm_msg);
1988
1989                /*
1990                 * we do not run diff between different kind
1991                 * of objects.
1992                 */
1993                if ((one->mode ^ two->mode) & S_IFMT)
1994                        goto free_ab_and_return;
1995                if (complete_rewrite &&
1996                    (textconv_one || !diff_filespec_is_binary(one)) &&
1997                    (textconv_two || !diff_filespec_is_binary(two))) {
1998                        fprintf(o->file, "%s", header.buf);
1999                        strbuf_reset(&header);
2000                        emit_rewrite_diff(name_a, name_b, one, two,
2001                                                textconv_one, textconv_two, o);
2002                        o->found_changes = 1;
2003                        goto free_ab_and_return;
2004                }
2005        }
2006
2007        if (o->irreversible_delete && lbl[1][0] == '/') {
2008                fprintf(o->file, "%s", header.buf);
2009                strbuf_reset(&header);
2010                goto free_ab_and_return;
2011        } else if (!DIFF_OPT_TST(o, TEXT) &&
2012            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2013              (!textconv_two && diff_filespec_is_binary(two)) )) {
2014                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2015                        die("unable to read files to diff");
2016                /* Quite common confusing case */
2017                if (mf1.size == mf2.size &&
2018                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2019                        if (must_show_header)
2020                                fprintf(o->file, "%s", header.buf);
2021                        goto free_ab_and_return;
2022                }
2023                fprintf(o->file, "%s", header.buf);
2024                strbuf_reset(&header);
2025                if (DIFF_OPT_TST(o, BINARY))
2026                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2027                else
2028                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2029                                line_prefix, lbl[0], lbl[1]);
2030                o->found_changes = 1;
2031        } else {
2032                /* Crazy xdl interfaces.. */
2033                const char *diffopts = getenv("GIT_DIFF_OPTS");
2034                xpparam_t xpp;
2035                xdemitconf_t xecfg;
2036                struct emit_callback ecbdata;
2037                const struct userdiff_funcname *pe;
2038
2039                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2040                        fprintf(o->file, "%s", header.buf);
2041                        strbuf_reset(&header);
2042                }
2043
2044                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2045                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2046
2047                pe = diff_funcname_pattern(one);
2048                if (!pe)
2049                        pe = diff_funcname_pattern(two);
2050
2051                memset(&xpp, 0, sizeof(xpp));
2052                memset(&xecfg, 0, sizeof(xecfg));
2053                memset(&ecbdata, 0, sizeof(ecbdata));
2054                ecbdata.label_path = lbl;
2055                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
2056                ecbdata.found_changesp = &o->found_changes;
2057                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2058                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2059                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2060                ecbdata.opt = o;
2061                ecbdata.header = header.len ? &header : NULL;
2062                xpp.flags = o->xdl_opts;
2063                xecfg.ctxlen = o->context;
2064                xecfg.interhunkctxlen = o->interhunkcontext;
2065                xecfg.flags = XDL_EMIT_FUNCNAMES;
2066                if (pe)
2067                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2068                if (!diffopts)
2069                        ;
2070                else if (!prefixcmp(diffopts, "--unified="))
2071                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2072                else if (!prefixcmp(diffopts, "-u"))
2073                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2074                if (o->word_diff) {
2075                        int i;
2076
2077                        ecbdata.diff_words =
2078                                xcalloc(1, sizeof(struct diff_words_data));
2079                        ecbdata.diff_words->type = o->word_diff;
2080                        ecbdata.diff_words->opt = o;
2081                        if (!o->word_regex)
2082                                o->word_regex = userdiff_word_regex(one);
2083                        if (!o->word_regex)
2084                                o->word_regex = userdiff_word_regex(two);
2085                        if (!o->word_regex)
2086                                o->word_regex = diff_word_regex_cfg;
2087                        if (o->word_regex) {
2088                                ecbdata.diff_words->word_regex = (regex_t *)
2089                                        xmalloc(sizeof(regex_t));
2090                                if (regcomp(ecbdata.diff_words->word_regex,
2091                                                o->word_regex,
2092                                                REG_EXTENDED | REG_NEWLINE))
2093                                        die ("Invalid regular expression: %s",
2094                                                        o->word_regex);
2095                        }
2096                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2097                                if (o->word_diff == diff_words_styles[i].type) {
2098                                        ecbdata.diff_words->style =
2099                                                &diff_words_styles[i];
2100                                        break;
2101                                }
2102                        }
2103                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2104                                struct diff_words_style *st = ecbdata.diff_words->style;
2105                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2106                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2107                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2108                        }
2109                }
2110                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2111                              &xpp, &xecfg);
2112                if (o->word_diff)
2113                        free_diff_words_data(&ecbdata);
2114                if (textconv_one)
2115                        free(mf1.ptr);
2116                if (textconv_two)
2117                        free(mf2.ptr);
2118                xdiff_clear_find_func(&xecfg);
2119        }
2120
2121 free_ab_and_return:
2122        strbuf_release(&header);
2123        diff_free_filespec_data(one);
2124        diff_free_filespec_data(two);
2125        free(a_one);
2126        free(b_two);
2127        return;
2128}
2129
2130static void builtin_diffstat(const char *name_a, const char *name_b,
2131                             struct diff_filespec *one,
2132                             struct diff_filespec *two,
2133                             struct diffstat_t *diffstat,
2134                             struct diff_options *o,
2135                             int complete_rewrite)
2136{
2137        mmfile_t mf1, mf2;
2138        struct diffstat_file *data;
2139
2140        data = diffstat_add(diffstat, name_a, name_b);
2141
2142        if (!one || !two) {
2143                data->is_unmerged = 1;
2144                return;
2145        }
2146
2147        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2148                data->is_binary = 1;
2149                data->added = diff_filespec_size(two);
2150                data->deleted = diff_filespec_size(one);
2151        }
2152
2153        else if (complete_rewrite) {
2154                diff_populate_filespec(one, 0);
2155                diff_populate_filespec(two, 0);
2156                data->deleted = count_lines(one->data, one->size);
2157                data->added = count_lines(two->data, two->size);
2158        }
2159
2160        else {
2161                /* Crazy xdl interfaces.. */
2162                xpparam_t xpp;
2163                xdemitconf_t xecfg;
2164
2165                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2166                        die("unable to read files to diff");
2167
2168                memset(&xpp, 0, sizeof(xpp));
2169                memset(&xecfg, 0, sizeof(xecfg));
2170                xpp.flags = o->xdl_opts;
2171                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2172                              &xpp, &xecfg);
2173        }
2174
2175        diff_free_filespec_data(one);
2176        diff_free_filespec_data(two);
2177}
2178
2179static void builtin_checkdiff(const char *name_a, const char *name_b,
2180                              const char *attr_path,
2181                              struct diff_filespec *one,
2182                              struct diff_filespec *two,
2183                              struct diff_options *o)
2184{
2185        mmfile_t mf1, mf2;
2186        struct checkdiff_t data;
2187
2188        if (!two)
2189                return;
2190
2191        memset(&data, 0, sizeof(data));
2192        data.filename = name_b ? name_b : name_a;
2193        data.lineno = 0;
2194        data.o = o;
2195        data.ws_rule = whitespace_rule(attr_path);
2196        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2197
2198        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2199                die("unable to read files to diff");
2200
2201        /*
2202         * All the other codepaths check both sides, but not checking
2203         * the "old" side here is deliberate.  We are checking the newly
2204         * introduced changes, and as long as the "new" side is text, we
2205         * can and should check what it introduces.
2206         */
2207        if (diff_filespec_is_binary(two))
2208                goto free_and_return;
2209        else {
2210                /* Crazy xdl interfaces.. */
2211                xpparam_t xpp;
2212                xdemitconf_t xecfg;
2213
2214                memset(&xpp, 0, sizeof(xpp));
2215                memset(&xecfg, 0, sizeof(xecfg));
2216                xecfg.ctxlen = 1; /* at least one context line */
2217                xpp.flags = 0;
2218                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2219                              &xpp, &xecfg);
2220
2221                if (data.ws_rule & WS_BLANK_AT_EOF) {
2222                        struct emit_callback ecbdata;
2223                        int blank_at_eof;
2224
2225                        ecbdata.ws_rule = data.ws_rule;
2226                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2227                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2228
2229                        if (blank_at_eof) {
2230                                static char *err;
2231                                if (!err)
2232                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2233                                fprintf(o->file, "%s:%d: %s.\n",
2234                                        data.filename, blank_at_eof, err);
2235                                data.status = 1; /* report errors */
2236                        }
2237                }
2238        }
2239 free_and_return:
2240        diff_free_filespec_data(one);
2241        diff_free_filespec_data(two);
2242        if (data.status)
2243                DIFF_OPT_SET(o, CHECK_FAILED);
2244}
2245
2246struct diff_filespec *alloc_filespec(const char *path)
2247{
2248        int namelen = strlen(path);
2249        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2250
2251        memset(spec, 0, sizeof(*spec));
2252        spec->path = (char *)(spec + 1);
2253        memcpy(spec->path, path, namelen+1);
2254        spec->count = 1;
2255        spec->is_binary = -1;
2256        return spec;
2257}
2258
2259void free_filespec(struct diff_filespec *spec)
2260{
2261        if (!--spec->count) {
2262                diff_free_filespec_data(spec);
2263                free(spec);
2264        }
2265}
2266
2267void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2268                   unsigned short mode)
2269{
2270        if (mode) {
2271                spec->mode = canon_mode(mode);
2272                hashcpy(spec->sha1, sha1);
2273                spec->sha1_valid = !is_null_sha1(sha1);
2274        }
2275}
2276
2277/*
2278 * Given a name and sha1 pair, if the index tells us the file in
2279 * the work tree has that object contents, return true, so that
2280 * prepare_temp_file() does not have to inflate and extract.
2281 */
2282static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2283{
2284        struct cache_entry *ce;
2285        struct stat st;
2286        int pos, len;
2287
2288        /*
2289         * We do not read the cache ourselves here, because the
2290         * benchmark with my previous version that always reads cache
2291         * shows that it makes things worse for diff-tree comparing
2292         * two linux-2.6 kernel trees in an already checked out work
2293         * tree.  This is because most diff-tree comparisons deal with
2294         * only a small number of files, while reading the cache is
2295         * expensive for a large project, and its cost outweighs the
2296         * savings we get by not inflating the object to a temporary
2297         * file.  Practically, this code only helps when we are used
2298         * by diff-cache --cached, which does read the cache before
2299         * calling us.
2300         */
2301        if (!active_cache)
2302                return 0;
2303
2304        /* We want to avoid the working directory if our caller
2305         * doesn't need the data in a normal file, this system
2306         * is rather slow with its stat/open/mmap/close syscalls,
2307         * and the object is contained in a pack file.  The pack
2308         * is probably already open and will be faster to obtain
2309         * the data through than the working directory.  Loose
2310         * objects however would tend to be slower as they need
2311         * to be individually opened and inflated.
2312         */
2313        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2314                return 0;
2315
2316        len = strlen(name);
2317        pos = cache_name_pos(name, len);
2318        if (pos < 0)
2319                return 0;
2320        ce = active_cache[pos];
2321
2322        /*
2323         * This is not the sha1 we are looking for, or
2324         * unreusable because it is not a regular file.
2325         */
2326        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2327                return 0;
2328
2329        /*
2330         * If ce is marked as "assume unchanged", there is no
2331         * guarantee that work tree matches what we are looking for.
2332         */
2333        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2334                return 0;
2335
2336        /*
2337         * If ce matches the file in the work tree, we can reuse it.
2338         */
2339        if (ce_uptodate(ce) ||
2340            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2341                return 1;
2342
2343        return 0;
2344}
2345
2346static int populate_from_stdin(struct diff_filespec *s)
2347{
2348        struct strbuf buf = STRBUF_INIT;
2349        size_t size = 0;
2350
2351        if (strbuf_read(&buf, 0, 0) < 0)
2352                return error("error while reading from stdin %s",
2353                                     strerror(errno));
2354
2355        s->should_munmap = 0;
2356        s->data = strbuf_detach(&buf, &size);
2357        s->size = size;
2358        s->should_free = 1;
2359        return 0;
2360}
2361
2362static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2363{
2364        int len;
2365        char *data = xmalloc(100), *dirty = "";
2366
2367        /* Are we looking at the work tree? */
2368        if (s->dirty_submodule)
2369                dirty = "-dirty";
2370
2371        len = snprintf(data, 100,
2372                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2373        s->data = data;
2374        s->size = len;
2375        s->should_free = 1;
2376        if (size_only) {
2377                s->data = NULL;
2378                free(data);
2379        }
2380        return 0;
2381}
2382
2383/*
2384 * While doing rename detection and pickaxe operation, we may need to
2385 * grab the data for the blob (or file) for our own in-core comparison.
2386 * diff_filespec has data and size fields for this purpose.
2387 */
2388int diff_populate_filespec(struct diff_filespec *s, int size_only)
2389{
2390        int err = 0;
2391        if (!DIFF_FILE_VALID(s))
2392                die("internal error: asking to populate invalid file.");
2393        if (S_ISDIR(s->mode))
2394                return -1;
2395
2396        if (s->data)
2397                return 0;
2398
2399        if (size_only && 0 < s->size)
2400                return 0;
2401
2402        if (S_ISGITLINK(s->mode))
2403                return diff_populate_gitlink(s, size_only);
2404
2405        if (!s->sha1_valid ||
2406            reuse_worktree_file(s->path, s->sha1, 0)) {
2407                struct strbuf buf = STRBUF_INIT;
2408                struct stat st;
2409                int fd;
2410
2411                if (!strcmp(s->path, "-"))
2412                        return populate_from_stdin(s);
2413
2414                if (lstat(s->path, &st) < 0) {
2415                        if (errno == ENOENT) {
2416                        err_empty:
2417                                err = -1;
2418                        empty:
2419                                s->data = (char *)"";
2420                                s->size = 0;
2421                                return err;
2422                        }
2423                }
2424                s->size = xsize_t(st.st_size);
2425                if (!s->size)
2426                        goto empty;
2427                if (S_ISLNK(st.st_mode)) {
2428                        struct strbuf sb = STRBUF_INIT;
2429
2430                        if (strbuf_readlink(&sb, s->path, s->size))
2431                                goto err_empty;
2432                        s->size = sb.len;
2433                        s->data = strbuf_detach(&sb, NULL);
2434                        s->should_free = 1;
2435                        return 0;
2436                }
2437                if (size_only)
2438                        return 0;
2439                fd = open(s->path, O_RDONLY);
2440                if (fd < 0)
2441                        goto err_empty;
2442                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2443                close(fd);
2444                s->should_munmap = 1;
2445
2446                /*
2447                 * Convert from working tree format to canonical git format
2448                 */
2449                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2450                        size_t size = 0;
2451                        munmap(s->data, s->size);
2452                        s->should_munmap = 0;
2453                        s->data = strbuf_detach(&buf, &size);
2454                        s->size = size;
2455                        s->should_free = 1;
2456                }
2457        }
2458        else {
2459                enum object_type type;
2460                if (size_only) {
2461                        type = sha1_object_info(s->sha1, &s->size);
2462                        if (type < 0)
2463                                die("unable to read %s", sha1_to_hex(s->sha1));
2464                } else {
2465                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2466                        if (!s->data)
2467                                die("unable to read %s", sha1_to_hex(s->sha1));
2468                        s->should_free = 1;
2469                }
2470        }
2471        return 0;
2472}
2473
2474void diff_free_filespec_blob(struct diff_filespec *s)
2475{
2476        if (s->should_free)
2477                free(s->data);
2478        else if (s->should_munmap)
2479                munmap(s->data, s->size);
2480
2481        if (s->should_free || s->should_munmap) {
2482                s->should_free = s->should_munmap = 0;
2483                s->data = NULL;
2484        }
2485}
2486
2487void diff_free_filespec_data(struct diff_filespec *s)
2488{
2489        diff_free_filespec_blob(s);
2490        free(s->cnt_data);
2491        s->cnt_data = NULL;
2492}
2493
2494static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2495                           void *blob,
2496                           unsigned long size,
2497                           const unsigned char *sha1,
2498                           int mode)
2499{
2500        int fd;
2501        struct strbuf buf = STRBUF_INIT;
2502        struct strbuf template = STRBUF_INIT;
2503        char *path_dup = xstrdup(path);
2504        const char *base = basename(path_dup);
2505
2506        /* Generate "XXXXXX_basename.ext" */
2507        strbuf_addstr(&template, "XXXXXX_");
2508        strbuf_addstr(&template, base);
2509
2510        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2511                        strlen(base) + 1);
2512        if (fd < 0)
2513                die_errno("unable to create temp-file");
2514        if (convert_to_working_tree(path,
2515                        (const char *)blob, (size_t)size, &buf)) {
2516                blob = buf.buf;
2517                size = buf.len;
2518        }
2519        if (write_in_full(fd, blob, size) != size)
2520                die_errno("unable to write temp-file");
2521        close(fd);
2522        temp->name = temp->tmp_path;
2523        strcpy(temp->hex, sha1_to_hex(sha1));
2524        temp->hex[40] = 0;
2525        sprintf(temp->mode, "%06o", mode);
2526        strbuf_release(&buf);
2527        strbuf_release(&template);
2528        free(path_dup);
2529}
2530
2531static struct diff_tempfile *prepare_temp_file(const char *name,
2532                struct diff_filespec *one)
2533{
2534        struct diff_tempfile *temp = claim_diff_tempfile();
2535
2536        if (!DIFF_FILE_VALID(one)) {
2537        not_a_valid_file:
2538                /* A '-' entry produces this for file-2, and
2539                 * a '+' entry produces this for file-1.
2540                 */
2541                temp->name = "/dev/null";
2542                strcpy(temp->hex, ".");
2543                strcpy(temp->mode, ".");
2544                return temp;
2545        }
2546
2547        if (!remove_tempfile_installed) {
2548                atexit(remove_tempfile);
2549                sigchain_push_common(remove_tempfile_on_signal);
2550                remove_tempfile_installed = 1;
2551        }
2552
2553        if (!one->sha1_valid ||
2554            reuse_worktree_file(name, one->sha1, 1)) {
2555                struct stat st;
2556                if (lstat(name, &st) < 0) {
2557                        if (errno == ENOENT)
2558                                goto not_a_valid_file;
2559                        die_errno("stat(%s)", name);
2560                }
2561                if (S_ISLNK(st.st_mode)) {
2562                        struct strbuf sb = STRBUF_INIT;
2563                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2564                                die_errno("readlink(%s)", name);
2565                        prep_temp_blob(name, temp, sb.buf, sb.len,
2566                                       (one->sha1_valid ?
2567                                        one->sha1 : null_sha1),
2568                                       (one->sha1_valid ?
2569                                        one->mode : S_IFLNK));
2570                        strbuf_release(&sb);
2571                }
2572                else {
2573                        /* we can borrow from the file in the work tree */
2574                        temp->name = name;
2575                        if (!one->sha1_valid)
2576                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2577                        else
2578                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2579                        /* Even though we may sometimes borrow the
2580                         * contents from the work tree, we always want
2581                         * one->mode.  mode is trustworthy even when
2582                         * !(one->sha1_valid), as long as
2583                         * DIFF_FILE_VALID(one).
2584                         */
2585                        sprintf(temp->mode, "%06o", one->mode);
2586                }
2587                return temp;
2588        }
2589        else {
2590                if (diff_populate_filespec(one, 0))
2591                        die("cannot read data blob for %s", one->path);
2592                prep_temp_blob(name, temp, one->data, one->size,
2593                               one->sha1, one->mode);
2594        }
2595        return temp;
2596}
2597
2598/* An external diff command takes:
2599 *
2600 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2601 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2602 *
2603 */
2604static void run_external_diff(const char *pgm,
2605                              const char *name,
2606                              const char *other,
2607                              struct diff_filespec *one,
2608                              struct diff_filespec *two,
2609                              const char *xfrm_msg,
2610                              int complete_rewrite)
2611{
2612        const char *spawn_arg[10];
2613        int retval;
2614        const char **arg = &spawn_arg[0];
2615
2616        if (one && two) {
2617                struct diff_tempfile *temp_one, *temp_two;
2618                const char *othername = (other ? other : name);
2619                temp_one = prepare_temp_file(name, one);
2620                temp_two = prepare_temp_file(othername, two);
2621                *arg++ = pgm;
2622                *arg++ = name;
2623                *arg++ = temp_one->name;
2624                *arg++ = temp_one->hex;
2625                *arg++ = temp_one->mode;
2626                *arg++ = temp_two->name;
2627                *arg++ = temp_two->hex;
2628                *arg++ = temp_two->mode;
2629                if (other) {
2630                        *arg++ = other;
2631                        *arg++ = xfrm_msg;
2632                }
2633        } else {
2634                *arg++ = pgm;
2635                *arg++ = name;
2636        }
2637        *arg = NULL;
2638        fflush(NULL);
2639        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2640        remove_tempfile();
2641        if (retval) {
2642                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2643                exit(1);
2644        }
2645}
2646
2647static int similarity_index(struct diff_filepair *p)
2648{
2649        return p->score * 100 / MAX_SCORE;
2650}
2651
2652static void fill_metainfo(struct strbuf *msg,
2653                          const char *name,
2654                          const char *other,
2655                          struct diff_filespec *one,
2656                          struct diff_filespec *two,
2657                          struct diff_options *o,
2658                          struct diff_filepair *p,
2659                          int *must_show_header,
2660                          int use_color)
2661{
2662        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2663        const char *reset = diff_get_color(use_color, DIFF_RESET);
2664        struct strbuf *msgbuf;
2665        char *line_prefix = "";
2666
2667        *must_show_header = 1;
2668        if (o->output_prefix) {
2669                msgbuf = o->output_prefix(o, o->output_prefix_data);
2670                line_prefix = msgbuf->buf;
2671        }
2672        strbuf_init(msg, PATH_MAX * 2 + 300);
2673        switch (p->status) {
2674        case DIFF_STATUS_COPIED:
2675                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2676                            line_prefix, set, similarity_index(p));
2677                strbuf_addf(msg, "%s\n%s%scopy from ",
2678                            reset,  line_prefix, set);
2679                quote_c_style(name, msg, NULL, 0);
2680                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2681                quote_c_style(other, msg, NULL, 0);
2682                strbuf_addf(msg, "%s\n", reset);
2683                break;
2684        case DIFF_STATUS_RENAMED:
2685                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2686                            line_prefix, set, similarity_index(p));
2687                strbuf_addf(msg, "%s\n%s%srename from ",
2688                            reset, line_prefix, set);
2689                quote_c_style(name, msg, NULL, 0);
2690                strbuf_addf(msg, "%s\n%s%srename to ",
2691                            reset, line_prefix, set);
2692                quote_c_style(other, msg, NULL, 0);
2693                strbuf_addf(msg, "%s\n", reset);
2694                break;
2695        case DIFF_STATUS_MODIFIED:
2696                if (p->score) {
2697                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2698                                    line_prefix,
2699                                    set, similarity_index(p), reset);
2700                        break;
2701                }
2702                /* fallthru */
2703        default:
2704                *must_show_header = 0;
2705        }
2706        if (one && two && hashcmp(one->sha1, two->sha1)) {
2707                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2708
2709                if (DIFF_OPT_TST(o, BINARY)) {
2710                        mmfile_t mf;
2711                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2712                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2713                                abbrev = 40;
2714                }
2715                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2716                            find_unique_abbrev(one->sha1, abbrev));
2717                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2718                if (one->mode == two->mode)
2719                        strbuf_addf(msg, " %06o", one->mode);
2720                strbuf_addf(msg, "%s\n", reset);
2721        }
2722}
2723
2724static void run_diff_cmd(const char *pgm,
2725                         const char *name,
2726                         const char *other,
2727                         const char *attr_path,
2728                         struct diff_filespec *one,
2729                         struct diff_filespec *two,
2730                         struct strbuf *msg,
2731                         struct diff_options *o,
2732                         struct diff_filepair *p)
2733{
2734        const char *xfrm_msg = NULL;
2735        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2736        int must_show_header = 0;
2737
2738        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2739                pgm = NULL;
2740        else {
2741                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2742                if (drv && drv->external)
2743                        pgm = drv->external;
2744        }
2745
2746        if (msg) {
2747                /*
2748                 * don't use colors when the header is intended for an
2749                 * external diff driver
2750                 */
2751                fill_metainfo(msg, name, other, one, two, o, p,
2752                              &must_show_header,
2753                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2754                xfrm_msg = msg->len ? msg->buf : NULL;
2755        }
2756
2757        if (pgm) {
2758                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2759                                  complete_rewrite);
2760                return;
2761        }
2762        if (one && two)
2763                builtin_diff(name, other ? other : name,
2764                             one, two, xfrm_msg, must_show_header,
2765                             o, complete_rewrite);
2766        else
2767                fprintf(o->file, "* Unmerged path %s\n", name);
2768}
2769
2770static void diff_fill_sha1_info(struct diff_filespec *one)
2771{
2772        if (DIFF_FILE_VALID(one)) {
2773                if (!one->sha1_valid) {
2774                        struct stat st;
2775                        if (!strcmp(one->path, "-")) {
2776                                hashcpy(one->sha1, null_sha1);
2777                                return;
2778                        }
2779                        if (lstat(one->path, &st) < 0)
2780                                die_errno("stat '%s'", one->path);
2781                        if (index_path(one->sha1, one->path, &st, 0))
2782                                die("cannot hash %s", one->path);
2783                }
2784        }
2785        else
2786                hashclr(one->sha1);
2787}
2788
2789static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2790{
2791        /* Strip the prefix but do not molest /dev/null and absolute paths */
2792        if (*namep && **namep != '/') {
2793                *namep += prefix_length;
2794                if (**namep == '/')
2795                        ++*namep;
2796        }
2797        if (*otherp && **otherp != '/') {
2798                *otherp += prefix_length;
2799                if (**otherp == '/')
2800                        ++*otherp;
2801        }
2802}
2803
2804static void run_diff(struct diff_filepair *p, struct diff_options *o)
2805{
2806        const char *pgm = external_diff();
2807        struct strbuf msg;
2808        struct diff_filespec *one = p->one;
2809        struct diff_filespec *two = p->two;
2810        const char *name;
2811        const char *other;
2812        const char *attr_path;
2813
2814        name  = p->one->path;
2815        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2816        attr_path = name;
2817        if (o->prefix_length)
2818                strip_prefix(o->prefix_length, &name, &other);
2819
2820        if (DIFF_PAIR_UNMERGED(p)) {
2821                run_diff_cmd(pgm, name, NULL, attr_path,
2822                             NULL, NULL, NULL, o, p);
2823                return;
2824        }
2825
2826        diff_fill_sha1_info(one);
2827        diff_fill_sha1_info(two);
2828
2829        if (!pgm &&
2830            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2831            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2832                /*
2833                 * a filepair that changes between file and symlink
2834                 * needs to be split into deletion and creation.
2835                 */
2836                struct diff_filespec *null = alloc_filespec(two->path);
2837                run_diff_cmd(NULL, name, other, attr_path,
2838                             one, null, &msg, o, p);
2839                free(null);
2840                strbuf_release(&msg);
2841
2842                null = alloc_filespec(one->path);
2843                run_diff_cmd(NULL, name, other, attr_path,
2844                             null, two, &msg, o, p);
2845                free(null);
2846        }
2847        else
2848                run_diff_cmd(pgm, name, other, attr_path,
2849                             one, two, &msg, o, p);
2850
2851        strbuf_release(&msg);
2852}
2853
2854static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2855                         struct diffstat_t *diffstat)
2856{
2857        const char *name;
2858        const char *other;
2859        int complete_rewrite = 0;
2860
2861        if (DIFF_PAIR_UNMERGED(p)) {
2862                /* unmerged */
2863                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2864                return;
2865        }
2866
2867        name = p->one->path;
2868        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2869
2870        if (o->prefix_length)
2871                strip_prefix(o->prefix_length, &name, &other);
2872
2873        diff_fill_sha1_info(p->one);
2874        diff_fill_sha1_info(p->two);
2875
2876        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2877                complete_rewrite = 1;
2878        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2879}
2880
2881static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2882{
2883        const char *name;
2884        const char *other;
2885        const char *attr_path;
2886
2887        if (DIFF_PAIR_UNMERGED(p)) {
2888                /* unmerged */
2889                return;
2890        }
2891
2892        name = p->one->path;
2893        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2894        attr_path = other ? other : name;
2895
2896        if (o->prefix_length)
2897                strip_prefix(o->prefix_length, &name, &other);
2898
2899        diff_fill_sha1_info(p->one);
2900        diff_fill_sha1_info(p->two);
2901
2902        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2903}
2904
2905void diff_setup(struct diff_options *options)
2906{
2907        memcpy(options, &default_diff_options, sizeof(*options));
2908
2909        options->file = stdout;
2910
2911        options->line_termination = '\n';
2912        options->break_opt = -1;
2913        options->rename_limit = -1;
2914        options->dirstat_percent = 3;
2915        options->context = 3;
2916
2917        options->change = diff_change;
2918        options->add_remove = diff_addremove;
2919        if (diff_use_color_default > 0)
2920                DIFF_OPT_SET(options, COLOR_DIFF);
2921        options->detect_rename = diff_detect_rename_default;
2922
2923        if (diff_no_prefix) {
2924                options->a_prefix = options->b_prefix = "";
2925        } else if (!diff_mnemonic_prefix) {
2926                options->a_prefix = "a/";
2927                options->b_prefix = "b/";
2928        }
2929}
2930
2931int diff_setup_done(struct diff_options *options)
2932{
2933        int count = 0;
2934
2935        if (options->output_format & DIFF_FORMAT_NAME)
2936                count++;
2937        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2938                count++;
2939        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2940                count++;
2941        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2942                count++;
2943        if (count > 1)
2944                die("--name-only, --name-status, --check and -s are mutually exclusive");
2945
2946        /*
2947         * Most of the time we can say "there are changes"
2948         * only by checking if there are changed paths, but
2949         * --ignore-whitespace* options force us to look
2950         * inside contents.
2951         */
2952
2953        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2954            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2955            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2956                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2957        else
2958                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2959
2960        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2961                options->detect_rename = DIFF_DETECT_COPY;
2962
2963        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2964                options->prefix = NULL;
2965        if (options->prefix)
2966                options->prefix_length = strlen(options->prefix);
2967        else
2968                options->prefix_length = 0;
2969
2970        if (options->output_format & (DIFF_FORMAT_NAME |
2971                                      DIFF_FORMAT_NAME_STATUS |
2972                                      DIFF_FORMAT_CHECKDIFF |
2973                                      DIFF_FORMAT_NO_OUTPUT))
2974                options->output_format &= ~(DIFF_FORMAT_RAW |
2975                                            DIFF_FORMAT_NUMSTAT |
2976                                            DIFF_FORMAT_DIFFSTAT |
2977                                            DIFF_FORMAT_SHORTSTAT |
2978                                            DIFF_FORMAT_DIRSTAT |
2979                                            DIFF_FORMAT_SUMMARY |
2980                                            DIFF_FORMAT_PATCH);
2981
2982        /*
2983         * These cases always need recursive; we do not drop caller-supplied
2984         * recursive bits for other formats here.
2985         */
2986        if (options->output_format & (DIFF_FORMAT_PATCH |
2987                                      DIFF_FORMAT_NUMSTAT |
2988                                      DIFF_FORMAT_DIFFSTAT |
2989                                      DIFF_FORMAT_SHORTSTAT |
2990                                      DIFF_FORMAT_DIRSTAT |
2991                                      DIFF_FORMAT_SUMMARY |
2992                                      DIFF_FORMAT_CHECKDIFF))
2993                DIFF_OPT_SET(options, RECURSIVE);
2994        /*
2995         * Also pickaxe would not work very well if you do not say recursive
2996         */
2997        if (options->pickaxe)
2998                DIFF_OPT_SET(options, RECURSIVE);
2999        /*
3000         * When patches are generated, submodules diffed against the work tree
3001         * must be checked for dirtiness too so it can be shown in the output
3002         */
3003        if (options->output_format & DIFF_FORMAT_PATCH)
3004                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3005
3006        if (options->detect_rename && options->rename_limit < 0)
3007                options->rename_limit = diff_rename_limit_default;
3008        if (options->setup & DIFF_SETUP_USE_CACHE) {
3009                if (!active_cache)
3010                        /* read-cache does not die even when it fails
3011                         * so it is safe for us to do this here.  Also
3012                         * it does not smudge active_cache or active_nr
3013                         * when it fails, so we do not have to worry about
3014                         * cleaning it up ourselves either.
3015                         */
3016                        read_cache();
3017        }
3018        if (options->abbrev <= 0 || 40 < options->abbrev)
3019                options->abbrev = 40; /* full */
3020
3021        /*
3022         * It does not make sense to show the first hit we happened
3023         * to have found.  It does not make sense not to return with
3024         * exit code in such a case either.
3025         */
3026        if (DIFF_OPT_TST(options, QUICK)) {
3027                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3028                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3029        }
3030
3031        return 0;
3032}
3033
3034static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3035{
3036        char c, *eq;
3037        int len;
3038
3039        if (*arg != '-')
3040                return 0;
3041        c = *++arg;
3042        if (!c)
3043                return 0;
3044        if (c == arg_short) {
3045                c = *++arg;
3046                if (!c)
3047                        return 1;
3048                if (val && isdigit(c)) {
3049                        char *end;
3050                        int n = strtoul(arg, &end, 10);
3051                        if (*end)
3052                                return 0;
3053                        *val = n;
3054                        return 1;
3055                }
3056                return 0;
3057        }
3058        if (c != '-')
3059                return 0;
3060        arg++;
3061        eq = strchr(arg, '=');
3062        if (eq)
3063                len = eq - arg;
3064        else
3065                len = strlen(arg);
3066        if (!len || strncmp(arg, arg_long, len))
3067                return 0;
3068        if (eq) {
3069                int n;
3070                char *end;
3071                if (!isdigit(*++eq))
3072                        return 0;
3073                n = strtoul(eq, &end, 10);
3074                if (*end)
3075                        return 0;
3076                *val = n;
3077        }
3078        return 1;
3079}
3080
3081static int diff_scoreopt_parse(const char *opt);
3082
3083static inline int short_opt(char opt, const char **argv,
3084                            const char **optarg)
3085{
3086        const char *arg = argv[0];
3087        if (arg[0] != '-' || arg[1] != opt)
3088                return 0;
3089        if (arg[2] != '\0') {
3090                *optarg = arg + 2;
3091                return 1;
3092        }
3093        if (!argv[1])
3094                die("Option '%c' requires a value", opt);
3095        *optarg = argv[1];
3096        return 2;
3097}
3098
3099int parse_long_opt(const char *opt, const char **argv,
3100                   const char **optarg)
3101{
3102        const char *arg = argv[0];
3103        if (arg[0] != '-' || arg[1] != '-')
3104                return 0;
3105        arg += strlen("--");
3106        if (prefixcmp(arg, opt))
3107                return 0;
3108        arg += strlen(opt);
3109        if (*arg == '=') { /* sticked form: --option=value */
3110                *optarg = arg + 1;
3111                return 1;
3112        }
3113        if (*arg != '\0')
3114                return 0;
3115        /* separate form: --option value */
3116        if (!argv[1])
3117                die("Option '--%s' requires a value", opt);
3118        *optarg = argv[1];
3119        return 2;
3120}
3121
3122static int stat_opt(struct diff_options *options, const char **av)
3123{
3124        const char *arg = av[0];
3125        char *end;
3126        int width = options->stat_width;
3127        int name_width = options->stat_name_width;
3128        int count = options->stat_count;
3129        int argcount = 1;
3130
3131        arg += strlen("--stat");
3132        end = (char *)arg;
3133
3134        switch (*arg) {
3135        case '-':
3136                if (!prefixcmp(arg, "-width")) {
3137                        arg += strlen("-width");
3138                        if (*arg == '=')
3139                                width = strtoul(arg + 1, &end, 10);
3140                        else if (!*arg && !av[1])
3141                                die("Option '--stat-width' requires a value");
3142                        else if (!*arg) {
3143                                width = strtoul(av[1], &end, 10);
3144                                argcount = 2;
3145                        }
3146                } else if (!prefixcmp(arg, "-name-width")) {
3147                        arg += strlen("-name-width");
3148                        if (*arg == '=')
3149                                name_width = strtoul(arg + 1, &end, 10);
3150                        else if (!*arg && !av[1])
3151                                die("Option '--stat-name-width' requires a value");
3152                        else if (!*arg) {
3153                                name_width = strtoul(av[1], &end, 10);
3154                                argcount = 2;
3155                        }
3156                } else if (!prefixcmp(arg, "-count")) {
3157                        arg += strlen("-count");
3158                        if (*arg == '=')
3159                                count = strtoul(arg + 1, &end, 10);
3160                        else if (!*arg && !av[1])
3161                                die("Option '--stat-count' requires a value");
3162                        else if (!*arg) {
3163                                count = strtoul(av[1], &end, 10);
3164                                argcount = 2;
3165                        }
3166                }
3167                break;
3168        case '=':
3169                width = strtoul(arg+1, &end, 10);
3170                if (*end == ',')
3171                        name_width = strtoul(end+1, &end, 10);
3172                if (*end == ',')
3173                        count = strtoul(end+1, &end, 10);
3174        }
3175
3176        /* Important! This checks all the error cases! */
3177        if (*end)
3178                return 0;
3179        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3180        options->stat_name_width = name_width;
3181        options->stat_width = width;
3182        options->stat_count = count;
3183        return argcount;
3184}
3185
3186int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3187{
3188        const char *arg = av[0];
3189        const char *optarg;
3190        int argcount;
3191
3192        /* Output format options */
3193        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3194                options->output_format |= DIFF_FORMAT_PATCH;
3195        else if (opt_arg(arg, 'U', "unified", &options->context))
3196                options->output_format |= DIFF_FORMAT_PATCH;
3197        else if (!strcmp(arg, "--raw"))
3198                options->output_format |= DIFF_FORMAT_RAW;
3199        else if (!strcmp(arg, "--patch-with-raw"))
3200                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3201        else if (!strcmp(arg, "--numstat"))
3202                options->output_format |= DIFF_FORMAT_NUMSTAT;
3203        else if (!strcmp(arg, "--shortstat"))
3204                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3205        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3206                options->output_format |= DIFF_FORMAT_DIRSTAT;
3207        else if (!strcmp(arg, "--cumulative")) {
3208                options->output_format |= DIFF_FORMAT_DIRSTAT;
3209                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3210        } else if (opt_arg(arg, 0, "dirstat-by-file",
3211                           &options->dirstat_percent)) {
3212                options->output_format |= DIFF_FORMAT_DIRSTAT;
3213                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3214        }
3215        else if (!strcmp(arg, "--check"))
3216                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3217        else if (!strcmp(arg, "--summary"))
3218                options->output_format |= DIFF_FORMAT_SUMMARY;
3219        else if (!strcmp(arg, "--patch-with-stat"))
3220                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3221        else if (!strcmp(arg, "--name-only"))
3222                options->output_format |= DIFF_FORMAT_NAME;
3223        else if (!strcmp(arg, "--name-status"))
3224                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3225        else if (!strcmp(arg, "-s"))
3226                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3227        else if (!prefixcmp(arg, "--stat"))
3228                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3229                return stat_opt(options, av);
3230
3231        /* renames options */
3232        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3233                 !strcmp(arg, "--break-rewrites")) {
3234                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3235                        return error("invalid argument to -B: %s", arg+2);
3236        }
3237        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3238                 !strcmp(arg, "--find-renames")) {
3239                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3240                        return error("invalid argument to -M: %s", arg+2);
3241                options->detect_rename = DIFF_DETECT_RENAME;
3242        }
3243        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3244                options->irreversible_delete = 1;
3245        }
3246        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3247                 !strcmp(arg, "--find-copies")) {
3248                if (options->detect_rename == DIFF_DETECT_COPY)
3249                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3250                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3251                        return error("invalid argument to -C: %s", arg+2);
3252                options->detect_rename = DIFF_DETECT_COPY;
3253        }
3254        else if (!strcmp(arg, "--no-renames"))
3255                options->detect_rename = 0;
3256        else if (!strcmp(arg, "--relative"))
3257                DIFF_OPT_SET(options, RELATIVE_NAME);
3258        else if (!prefixcmp(arg, "--relative=")) {
3259                DIFF_OPT_SET(options, RELATIVE_NAME);
3260                options->prefix = arg + 11;
3261        }
3262
3263        /* xdiff options */
3264        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3265                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3266        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3267                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3268        else if (!strcmp(arg, "--ignore-space-at-eol"))
3269                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3270        else if (!strcmp(arg, "--patience"))
3271                DIFF_XDL_SET(options, PATIENCE_DIFF);
3272
3273        /* flags options */
3274        else if (!strcmp(arg, "--binary")) {
3275                options->output_format |= DIFF_FORMAT_PATCH;
3276                DIFF_OPT_SET(options, BINARY);
3277        }
3278        else if (!strcmp(arg, "--full-index"))
3279                DIFF_OPT_SET(options, FULL_INDEX);
3280        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3281                DIFF_OPT_SET(options, TEXT);
3282        else if (!strcmp(arg, "-R"))
3283                DIFF_OPT_SET(options, REVERSE_DIFF);
3284        else if (!strcmp(arg, "--find-copies-harder"))
3285                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3286        else if (!strcmp(arg, "--follow"))
3287                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3288        else if (!strcmp(arg, "--color"))
3289                DIFF_OPT_SET(options, COLOR_DIFF);
3290        else if (!prefixcmp(arg, "--color=")) {
3291                int value = git_config_colorbool(NULL, arg+8, -1);
3292                if (value == 0)
3293                        DIFF_OPT_CLR(options, COLOR_DIFF);
3294                else if (value > 0)
3295                        DIFF_OPT_SET(options, COLOR_DIFF);
3296                else
3297                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3298        }
3299        else if (!strcmp(arg, "--no-color"))
3300                DIFF_OPT_CLR(options, COLOR_DIFF);
3301        else if (!strcmp(arg, "--color-words")) {
3302                DIFF_OPT_SET(options, COLOR_DIFF);
3303                options->word_diff = DIFF_WORDS_COLOR;
3304        }
3305        else if (!prefixcmp(arg, "--color-words=")) {
3306                DIFF_OPT_SET(options, COLOR_DIFF);
3307                options->word_diff = DIFF_WORDS_COLOR;
3308                options->word_regex = arg + 14;
3309        }
3310        else if (!strcmp(arg, "--word-diff")) {
3311                if (options->word_diff == DIFF_WORDS_NONE)
3312                        options->word_diff = DIFF_WORDS_PLAIN;
3313        }
3314        else if (!prefixcmp(arg, "--word-diff=")) {
3315                const char *type = arg + 12;
3316                if (!strcmp(type, "plain"))
3317                        options->word_diff = DIFF_WORDS_PLAIN;
3318                else if (!strcmp(type, "color")) {
3319                        DIFF_OPT_SET(options, COLOR_DIFF);
3320                        options->word_diff = DIFF_WORDS_COLOR;
3321                }
3322                else if (!strcmp(type, "porcelain"))
3323                        options->word_diff = DIFF_WORDS_PORCELAIN;
3324                else if (!strcmp(type, "none"))
3325                        options->word_diff = DIFF_WORDS_NONE;
3326                else
3327                        die("bad --word-diff argument: %s", type);
3328        }
3329        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3330                if (options->word_diff == DIFF_WORDS_NONE)
3331                        options->word_diff = DIFF_WORDS_PLAIN;
3332                options->word_regex = optarg;
3333                return argcount;
3334        }
3335        else if (!strcmp(arg, "--exit-code"))
3336                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3337        else if (!strcmp(arg, "--quiet"))
3338                DIFF_OPT_SET(options, QUICK);
3339        else if (!strcmp(arg, "--ext-diff"))
3340                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3341        else if (!strcmp(arg, "--no-ext-diff"))
3342                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3343        else if (!strcmp(arg, "--textconv"))
3344                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3345        else if (!strcmp(arg, "--no-textconv"))
3346                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3347        else if (!strcmp(arg, "--ignore-submodules")) {
3348                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3349                handle_ignore_submodules_arg(options, "all");
3350        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3351                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3352                handle_ignore_submodules_arg(options, arg + 20);
3353        } else if (!strcmp(arg, "--submodule"))
3354                DIFF_OPT_SET(options, SUBMODULE_LOG);
3355        else if (!prefixcmp(arg, "--submodule=")) {
3356                if (!strcmp(arg + 12, "log"))
3357                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3358        }
3359
3360        /* misc options */
3361        else if (!strcmp(arg, "-z"))
3362                options->line_termination = 0;
3363        else if ((argcount = short_opt('l', av, &optarg))) {
3364                options->rename_limit = strtoul(optarg, NULL, 10);
3365                return argcount;
3366        }
3367        else if ((argcount = short_opt('S', av, &optarg))) {
3368                options->pickaxe = optarg;
3369                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3370                return argcount;
3371        } else if ((argcount = short_opt('G', av, &optarg))) {
3372                options->pickaxe = optarg;
3373                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3374                return argcount;
3375        }
3376        else if (!strcmp(arg, "--pickaxe-all"))
3377                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3378        else if (!strcmp(arg, "--pickaxe-regex"))
3379                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3380        else if ((argcount = short_opt('O', av, &optarg))) {
3381                options->orderfile = optarg;
3382                return argcount;
3383        }
3384        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3385                options->filter = optarg;
3386                return argcount;
3387        }
3388        else if (!strcmp(arg, "--abbrev"))
3389                options->abbrev = DEFAULT_ABBREV;
3390        else if (!prefixcmp(arg, "--abbrev=")) {
3391                options->abbrev = strtoul(arg + 9, NULL, 10);
3392                if (options->abbrev < MINIMUM_ABBREV)
3393                        options->abbrev = MINIMUM_ABBREV;
3394                else if (40 < options->abbrev)
3395                        options->abbrev = 40;
3396        }
3397        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3398                options->a_prefix = optarg;
3399                return argcount;
3400        }
3401        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3402                options->b_prefix = optarg;
3403                return argcount;
3404        }
3405        else if (!strcmp(arg, "--no-prefix"))
3406                options->a_prefix = options->b_prefix = "";
3407        else if (opt_arg(arg, '\0', "inter-hunk-context",
3408                         &options->interhunkcontext))
3409                ;
3410        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3411                options->file = fopen(optarg, "w");
3412                if (!options->file)
3413                        die_errno("Could not open '%s'", optarg);
3414                options->close_file = 1;
3415                return argcount;
3416        } else
3417                return 0;
3418        return 1;
3419}
3420
3421int parse_rename_score(const char **cp_p)
3422{
3423        unsigned long num, scale;
3424        int ch, dot;
3425        const char *cp = *cp_p;
3426
3427        num = 0;
3428        scale = 1;
3429        dot = 0;
3430        for (;;) {
3431                ch = *cp;
3432                if ( !dot && ch == '.' ) {
3433                        scale = 1;
3434                        dot = 1;
3435                } else if ( ch == '%' ) {
3436                        scale = dot ? scale*100 : 100;
3437                        cp++;   /* % is always at the end */
3438                        break;
3439                } else if ( ch >= '0' && ch <= '9' ) {
3440                        if ( scale < 100000 ) {
3441                                scale *= 10;
3442                                num = (num*10) + (ch-'0');
3443                        }
3444                } else {
3445                        break;
3446                }
3447                cp++;
3448        }
3449        *cp_p = cp;
3450
3451        /* user says num divided by scale and we say internally that
3452         * is MAX_SCORE * num / scale.
3453         */
3454        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3455}
3456
3457static int diff_scoreopt_parse(const char *opt)
3458{
3459        int opt1, opt2, cmd;
3460
3461        if (*opt++ != '-')
3462                return -1;
3463        cmd = *opt++;
3464        if (cmd == '-') {
3465                /* convert the long-form arguments into short-form versions */
3466                if (!prefixcmp(opt, "break-rewrites")) {
3467                        opt += strlen("break-rewrites");
3468                        if (*opt == 0 || *opt++ == '=')
3469                                cmd = 'B';
3470                } else if (!prefixcmp(opt, "find-copies")) {
3471                        opt += strlen("find-copies");
3472                        if (*opt == 0 || *opt++ == '=')
3473                                cmd = 'C';
3474                } else if (!prefixcmp(opt, "find-renames")) {
3475                        opt += strlen("find-renames");
3476                        if (*opt == 0 || *opt++ == '=')
3477                                cmd = 'M';
3478                }
3479        }
3480        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3481                return -1; /* that is not a -M, -C nor -B option */
3482
3483        opt1 = parse_rename_score(&opt);
3484        if (cmd != 'B')
3485                opt2 = 0;
3486        else {
3487                if (*opt == 0)
3488                        opt2 = 0;
3489                else if (*opt != '/')
3490                        return -1; /* we expect -B80/99 or -B80 */
3491                else {
3492                        opt++;
3493                        opt2 = parse_rename_score(&opt);
3494                }
3495        }
3496        if (*opt != 0)
3497                return -1;
3498        return opt1 | (opt2 << 16);
3499}
3500
3501struct diff_queue_struct diff_queued_diff;
3502
3503void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3504{
3505        if (queue->alloc <= queue->nr) {
3506                queue->alloc = alloc_nr(queue->alloc);
3507                queue->queue = xrealloc(queue->queue,
3508                                        sizeof(dp) * queue->alloc);
3509        }
3510        queue->queue[queue->nr++] = dp;
3511}
3512
3513struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3514                                 struct diff_filespec *one,
3515                                 struct diff_filespec *two)
3516{
3517        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3518        dp->one = one;
3519        dp->two = two;
3520        if (queue)
3521                diff_q(queue, dp);
3522        return dp;
3523}
3524
3525void diff_free_filepair(struct diff_filepair *p)
3526{
3527        free_filespec(p->one);
3528        free_filespec(p->two);
3529        free(p);
3530}
3531
3532/* This is different from find_unique_abbrev() in that
3533 * it stuffs the result with dots for alignment.
3534 */
3535const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3536{
3537        int abblen;
3538        const char *abbrev;
3539        if (len == 40)
3540                return sha1_to_hex(sha1);
3541
3542        abbrev = find_unique_abbrev(sha1, len);
3543        abblen = strlen(abbrev);
3544        if (abblen < 37) {
3545                static char hex[41];
3546                if (len < abblen && abblen <= len + 2)
3547                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3548                else
3549                        sprintf(hex, "%s...", abbrev);
3550                return hex;
3551        }
3552        return sha1_to_hex(sha1);
3553}
3554
3555static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3556{
3557        int line_termination = opt->line_termination;
3558        int inter_name_termination = line_termination ? '\t' : '\0';
3559        if (opt->output_prefix) {
3560                struct strbuf *msg = NULL;
3561                msg = opt->output_prefix(opt, opt->output_prefix_data);
3562                fprintf(opt->file, "%s", msg->buf);
3563        }
3564
3565        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3566                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3567                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3568                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3569        }
3570        if (p->score) {
3571                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3572                        inter_name_termination);
3573        } else {
3574                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3575        }
3576
3577        if (p->status == DIFF_STATUS_COPIED ||
3578            p->status == DIFF_STATUS_RENAMED) {
3579                const char *name_a, *name_b;
3580                name_a = p->one->path;
3581                name_b = p->two->path;
3582                strip_prefix(opt->prefix_length, &name_a, &name_b);
3583                write_name_quoted(name_a, opt->file, inter_name_termination);
3584                write_name_quoted(name_b, opt->file, line_termination);
3585        } else {
3586                const char *name_a, *name_b;
3587                name_a = p->one->mode ? p->one->path : p->two->path;
3588                name_b = NULL;
3589                strip_prefix(opt->prefix_length, &name_a, &name_b);
3590                write_name_quoted(name_a, opt->file, line_termination);
3591        }
3592}
3593
3594int diff_unmodified_pair(struct diff_filepair *p)
3595{
3596        /* This function is written stricter than necessary to support
3597         * the currently implemented transformers, but the idea is to
3598         * let transformers to produce diff_filepairs any way they want,
3599         * and filter and clean them up here before producing the output.
3600         */
3601        struct diff_filespec *one = p->one, *two = p->two;
3602
3603        if (DIFF_PAIR_UNMERGED(p))
3604                return 0; /* unmerged is interesting */
3605
3606        /* deletion, addition, mode or type change
3607         * and rename are all interesting.
3608         */
3609        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3610            DIFF_PAIR_MODE_CHANGED(p) ||
3611            strcmp(one->path, two->path))
3612                return 0;
3613
3614        /* both are valid and point at the same path.  that is, we are
3615         * dealing with a change.
3616         */
3617        if (one->sha1_valid && two->sha1_valid &&
3618            !hashcmp(one->sha1, two->sha1) &&
3619            !one->dirty_submodule && !two->dirty_submodule)
3620                return 1; /* no change */
3621        if (!one->sha1_valid && !two->sha1_valid)
3622                return 1; /* both look at the same file on the filesystem. */
3623        return 0;
3624}
3625
3626static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3627{
3628        if (diff_unmodified_pair(p))
3629                return;
3630
3631        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3632            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3633                return; /* no tree diffs in patch format */
3634
3635        run_diff(p, o);
3636}
3637
3638static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3639                            struct diffstat_t *diffstat)
3640{
3641        if (diff_unmodified_pair(p))
3642                return;
3643
3644        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3645            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3646                return; /* no useful stat for tree diffs */
3647
3648        run_diffstat(p, o, diffstat);
3649}
3650
3651static void diff_flush_checkdiff(struct diff_filepair *p,
3652                struct diff_options *o)
3653{
3654        if (diff_unmodified_pair(p))
3655                return;
3656
3657        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3658            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3659                return; /* nothing to check in tree diffs */
3660
3661        run_checkdiff(p, o);
3662}
3663
3664int diff_queue_is_empty(void)
3665{
3666        struct diff_queue_struct *q = &diff_queued_diff;
3667        int i;
3668        for (i = 0; i < q->nr; i++)
3669                if (!diff_unmodified_pair(q->queue[i]))
3670                        return 0;
3671        return 1;
3672}
3673
3674#if DIFF_DEBUG
3675void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3676{
3677        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3678                x, one ? one : "",
3679                s->path,
3680                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3681                s->mode,
3682                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3683        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3684                x, one ? one : "",
3685                s->size, s->xfrm_flags);
3686}
3687
3688void diff_debug_filepair(const struct diff_filepair *p, int i)
3689{
3690        diff_debug_filespec(p->one, i, "one");
3691        diff_debug_filespec(p->two, i, "two");
3692        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3693                p->score, p->status ? p->status : '?',
3694                p->one->rename_used, p->broken_pair);
3695}
3696
3697void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3698{
3699        int i;
3700        if (msg)
3701                fprintf(stderr, "%s\n", msg);
3702        fprintf(stderr, "q->nr = %d\n", q->nr);
3703        for (i = 0; i < q->nr; i++) {
3704                struct diff_filepair *p = q->queue[i];
3705                diff_debug_filepair(p, i);
3706        }
3707}
3708#endif
3709
3710static void diff_resolve_rename_copy(void)
3711{
3712        int i;
3713        struct diff_filepair *p;
3714        struct diff_queue_struct *q = &diff_queued_diff;
3715
3716        diff_debug_queue("resolve-rename-copy", q);
3717
3718        for (i = 0; i < q->nr; i++) {
3719                p = q->queue[i];
3720                p->status = 0; /* undecided */
3721                if (DIFF_PAIR_UNMERGED(p))
3722                        p->status = DIFF_STATUS_UNMERGED;
3723                else if (!DIFF_FILE_VALID(p->one))
3724                        p->status = DIFF_STATUS_ADDED;
3725                else if (!DIFF_FILE_VALID(p->two))
3726                        p->status = DIFF_STATUS_DELETED;
3727                else if (DIFF_PAIR_TYPE_CHANGED(p))
3728                        p->status = DIFF_STATUS_TYPE_CHANGED;
3729
3730                /* from this point on, we are dealing with a pair
3731                 * whose both sides are valid and of the same type, i.e.
3732                 * either in-place edit or rename/copy edit.
3733                 */
3734                else if (DIFF_PAIR_RENAME(p)) {
3735                        /*
3736                         * A rename might have re-connected a broken
3737                         * pair up, causing the pathnames to be the
3738                         * same again. If so, that's not a rename at
3739                         * all, just a modification..
3740                         *
3741                         * Otherwise, see if this source was used for
3742                         * multiple renames, in which case we decrement
3743                         * the count, and call it a copy.
3744                         */
3745                        if (!strcmp(p->one->path, p->two->path))
3746                                p->status = DIFF_STATUS_MODIFIED;
3747                        else if (--p->one->rename_used > 0)
3748                                p->status = DIFF_STATUS_COPIED;
3749                        else
3750                                p->status = DIFF_STATUS_RENAMED;
3751                }
3752                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3753                         p->one->mode != p->two->mode ||
3754                         p->one->dirty_submodule ||
3755                         p->two->dirty_submodule ||
3756                         is_null_sha1(p->one->sha1))
3757                        p->status = DIFF_STATUS_MODIFIED;
3758                else {
3759                        /* This is a "no-change" entry and should not
3760                         * happen anymore, but prepare for broken callers.
3761                         */
3762                        error("feeding unmodified %s to diffcore",
3763                              p->one->path);
3764                        p->status = DIFF_STATUS_UNKNOWN;
3765                }
3766        }
3767        diff_debug_queue("resolve-rename-copy done", q);
3768}
3769
3770static int check_pair_status(struct diff_filepair *p)
3771{
3772        switch (p->status) {
3773        case DIFF_STATUS_UNKNOWN:
3774                return 0;
3775        case 0:
3776                die("internal error in diff-resolve-rename-copy");
3777        default:
3778                return 1;
3779        }
3780}
3781
3782static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3783{
3784        int fmt = opt->output_format;
3785
3786        if (fmt & DIFF_FORMAT_CHECKDIFF)
3787                diff_flush_checkdiff(p, opt);
3788        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3789                diff_flush_raw(p, opt);
3790        else if (fmt & DIFF_FORMAT_NAME) {
3791                const char *name_a, *name_b;
3792                name_a = p->two->path;
3793                name_b = NULL;
3794                strip_prefix(opt->prefix_length, &name_a, &name_b);
3795                write_name_quoted(name_a, opt->file, opt->line_termination);
3796        }
3797}
3798
3799static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3800{
3801        if (fs->mode)
3802                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3803        else
3804                fprintf(file, " %s ", newdelete);
3805        write_name_quoted(fs->path, file, '\n');
3806}
3807
3808
3809static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3810                const char *line_prefix)
3811{
3812        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3813                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3814                        p->two->mode, show_name ? ' ' : '\n');
3815                if (show_name) {
3816                        write_name_quoted(p->two->path, file, '\n');
3817                }
3818        }
3819}
3820
3821static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3822                        const char *line_prefix)
3823{
3824        char *names = pprint_rename(p->one->path, p->two->path);
3825
3826        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3827        free(names);
3828        show_mode_change(file, p, 0, line_prefix);
3829}
3830
3831static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3832{
3833        FILE *file = opt->file;
3834        char *line_prefix = "";
3835
3836        if (opt->output_prefix) {
3837                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3838                line_prefix = buf->buf;
3839        }
3840
3841        switch(p->status) {
3842        case DIFF_STATUS_DELETED:
3843                fputs(line_prefix, file);
3844                show_file_mode_name(file, "delete", p->one);
3845                break;
3846        case DIFF_STATUS_ADDED:
3847                fputs(line_prefix, file);
3848                show_file_mode_name(file, "create", p->two);
3849                break;
3850        case DIFF_STATUS_COPIED:
3851                fputs(line_prefix, file);
3852                show_rename_copy(file, "copy", p, line_prefix);
3853                break;
3854        case DIFF_STATUS_RENAMED:
3855                fputs(line_prefix, file);
3856                show_rename_copy(file, "rename", p, line_prefix);
3857                break;
3858        default:
3859                if (p->score) {
3860                        fprintf(file, "%s rewrite ", line_prefix);
3861                        write_name_quoted(p->two->path, file, ' ');
3862                        fprintf(file, "(%d%%)\n", similarity_index(p));
3863                }
3864                show_mode_change(file, p, !p->score, line_prefix);
3865                break;
3866        }
3867}
3868
3869struct patch_id_t {
3870        git_SHA_CTX *ctx;
3871        int patchlen;
3872};
3873
3874static int remove_space(char *line, int len)
3875{
3876        int i;
3877        char *dst = line;
3878        unsigned char c;
3879
3880        for (i = 0; i < len; i++)
3881                if (!isspace((c = line[i])))
3882                        *dst++ = c;
3883
3884        return dst - line;
3885}
3886
3887static void patch_id_consume(void *priv, char *line, unsigned long len)
3888{
3889        struct patch_id_t *data = priv;
3890        int new_len;
3891
3892        /* Ignore line numbers when computing the SHA1 of the patch */
3893        if (!prefixcmp(line, "@@ -"))
3894                return;
3895
3896        new_len = remove_space(line, len);
3897
3898        git_SHA1_Update(data->ctx, line, new_len);
3899        data->patchlen += new_len;
3900}
3901
3902/* returns 0 upon success, and writes result into sha1 */
3903static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3904{
3905        struct diff_queue_struct *q = &diff_queued_diff;
3906        int i;
3907        git_SHA_CTX ctx;
3908        struct patch_id_t data;
3909        char buffer[PATH_MAX * 4 + 20];
3910
3911        git_SHA1_Init(&ctx);
3912        memset(&data, 0, sizeof(struct patch_id_t));
3913        data.ctx = &ctx;
3914
3915        for (i = 0; i < q->nr; i++) {
3916                xpparam_t xpp;
3917                xdemitconf_t xecfg;
3918                mmfile_t mf1, mf2;
3919                struct diff_filepair *p = q->queue[i];
3920                int len1, len2;
3921
3922                memset(&xpp, 0, sizeof(xpp));
3923                memset(&xecfg, 0, sizeof(xecfg));
3924                if (p->status == 0)
3925                        return error("internal diff status error");
3926                if (p->status == DIFF_STATUS_UNKNOWN)
3927                        continue;
3928                if (diff_unmodified_pair(p))
3929                        continue;
3930                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3931                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3932                        continue;
3933                if (DIFF_PAIR_UNMERGED(p))
3934                        continue;
3935
3936                diff_fill_sha1_info(p->one);
3937                diff_fill_sha1_info(p->two);
3938                if (fill_mmfile(&mf1, p->one) < 0 ||
3939                                fill_mmfile(&mf2, p->two) < 0)
3940                        return error("unable to read files to diff");
3941
3942                len1 = remove_space(p->one->path, strlen(p->one->path));
3943                len2 = remove_space(p->two->path, strlen(p->two->path));
3944                if (p->one->mode == 0)
3945                        len1 = snprintf(buffer, sizeof(buffer),
3946                                        "diff--gita/%.*sb/%.*s"
3947                                        "newfilemode%06o"
3948                                        "---/dev/null"
3949                                        "+++b/%.*s",
3950                                        len1, p->one->path,
3951                                        len2, p->two->path,
3952                                        p->two->mode,
3953                                        len2, p->two->path);
3954                else if (p->two->mode == 0)
3955                        len1 = snprintf(buffer, sizeof(buffer),
3956                                        "diff--gita/%.*sb/%.*s"
3957                                        "deletedfilemode%06o"
3958                                        "---a/%.*s"
3959                                        "+++/dev/null",
3960                                        len1, p->one->path,
3961                                        len2, p->two->path,
3962                                        p->one->mode,
3963                                        len1, p->one->path);
3964                else
3965                        len1 = snprintf(buffer, sizeof(buffer),
3966                                        "diff--gita/%.*sb/%.*s"
3967                                        "---a/%.*s"
3968                                        "+++b/%.*s",
3969                                        len1, p->one->path,
3970                                        len2, p->two->path,
3971                                        len1, p->one->path,
3972                                        len2, p->two->path);
3973                git_SHA1_Update(&ctx, buffer, len1);
3974
3975                if (diff_filespec_is_binary(p->one) ||
3976                    diff_filespec_is_binary(p->two)) {
3977                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
3978                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
3979                        continue;
3980                }
3981
3982                xpp.flags = 0;
3983                xecfg.ctxlen = 3;
3984                xecfg.flags = 0;
3985                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3986                              &xpp, &xecfg);
3987        }
3988
3989        git_SHA1_Final(sha1, &ctx);
3990        return 0;
3991}
3992
3993int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3994{
3995        struct diff_queue_struct *q = &diff_queued_diff;
3996        int i;
3997        int result = diff_get_patch_id(options, sha1);
3998
3999        for (i = 0; i < q->nr; i++)
4000                diff_free_filepair(q->queue[i]);
4001
4002        free(q->queue);
4003        DIFF_QUEUE_CLEAR(q);
4004
4005        return result;
4006}
4007
4008static int is_summary_empty(const struct diff_queue_struct *q)
4009{
4010        int i;
4011
4012        for (i = 0; i < q->nr; i++) {
4013                const struct diff_filepair *p = q->queue[i];
4014
4015                switch (p->status) {
4016                case DIFF_STATUS_DELETED:
4017                case DIFF_STATUS_ADDED:
4018                case DIFF_STATUS_COPIED:
4019                case DIFF_STATUS_RENAMED:
4020                        return 0;
4021                default:
4022                        if (p->score)
4023                                return 0;
4024                        if (p->one->mode && p->two->mode &&
4025                            p->one->mode != p->two->mode)
4026                                return 0;
4027                        break;
4028                }
4029        }
4030        return 1;
4031}
4032
4033static const char rename_limit_warning[] =
4034"inexact rename detection was skipped due to too many files.";
4035
4036static const char degrade_cc_to_c_warning[] =
4037"only found copies from modified paths due to too many files.";
4038
4039static const char rename_limit_advice[] =
4040"you may want to set your %s variable to at least "
4041"%d and retry the command.";
4042
4043void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4044{
4045        if (degraded_cc)
4046                warning(degrade_cc_to_c_warning);
4047        else if (needed)
4048                warning(rename_limit_warning);
4049        else
4050                return;
4051        if (0 < needed && needed < 32767)
4052                warning(rename_limit_advice, varname, needed);
4053}
4054
4055void diff_flush(struct diff_options *options)
4056{
4057        struct diff_queue_struct *q = &diff_queued_diff;
4058        int i, output_format = options->output_format;
4059        int separator = 0;
4060
4061        /*
4062         * Order: raw, stat, summary, patch
4063         * or:    name/name-status/checkdiff (other bits clear)
4064         */
4065        if (!q->nr)
4066                goto free_queue;
4067
4068        if (output_format & (DIFF_FORMAT_RAW |
4069                             DIFF_FORMAT_NAME |
4070                             DIFF_FORMAT_NAME_STATUS |
4071                             DIFF_FORMAT_CHECKDIFF)) {
4072                for (i = 0; i < q->nr; i++) {
4073                        struct diff_filepair *p = q->queue[i];
4074                        if (check_pair_status(p))
4075                                flush_one_pair(p, options);
4076                }
4077                separator++;
4078        }
4079
4080        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
4081                struct diffstat_t diffstat;
4082
4083                memset(&diffstat, 0, sizeof(struct diffstat_t));
4084                for (i = 0; i < q->nr; i++) {
4085                        struct diff_filepair *p = q->queue[i];
4086                        if (check_pair_status(p))
4087                                diff_flush_stat(p, options, &diffstat);
4088                }
4089                if (output_format & DIFF_FORMAT_NUMSTAT)
4090                        show_numstat(&diffstat, options);
4091                if (output_format & DIFF_FORMAT_DIFFSTAT)
4092                        show_stats(&diffstat, options);
4093                if (output_format & DIFF_FORMAT_SHORTSTAT)
4094                        show_shortstats(&diffstat, options);
4095                free_diffstat_info(&diffstat);
4096                separator++;
4097        }
4098        if (output_format & DIFF_FORMAT_DIRSTAT)
4099                show_dirstat(options);
4100
4101        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4102                for (i = 0; i < q->nr; i++) {
4103                        diff_summary(options, q->queue[i]);
4104                }
4105                separator++;
4106        }
4107
4108        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4109            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4110            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4111                /*
4112                 * run diff_flush_patch for the exit status. setting
4113                 * options->file to /dev/null should be safe, becaue we
4114                 * aren't supposed to produce any output anyway.
4115                 */
4116                if (options->close_file)
4117                        fclose(options->file);
4118                options->file = fopen("/dev/null", "w");
4119                if (!options->file)
4120                        die_errno("Could not open /dev/null");
4121                options->close_file = 1;
4122                for (i = 0; i < q->nr; i++) {
4123                        struct diff_filepair *p = q->queue[i];
4124                        if (check_pair_status(p))
4125                                diff_flush_patch(p, options);
4126                        if (options->found_changes)
4127                                break;
4128                }
4129        }
4130
4131        if (output_format & DIFF_FORMAT_PATCH) {
4132                if (separator) {
4133                        putc(options->line_termination, options->file);
4134                        if (options->stat_sep) {
4135                                /* attach patch instead of inline */
4136                                fputs(options->stat_sep, options->file);
4137                        }
4138                }
4139
4140                for (i = 0; i < q->nr; i++) {
4141                        struct diff_filepair *p = q->queue[i];
4142                        if (check_pair_status(p))
4143                                diff_flush_patch(p, options);
4144                }
4145        }
4146
4147        if (output_format & DIFF_FORMAT_CALLBACK)
4148                options->format_callback(q, options, options->format_callback_data);
4149
4150        for (i = 0; i < q->nr; i++)
4151                diff_free_filepair(q->queue[i]);
4152free_queue:
4153        free(q->queue);
4154        DIFF_QUEUE_CLEAR(q);
4155        if (options->close_file)
4156                fclose(options->file);
4157
4158        /*
4159         * Report the content-level differences with HAS_CHANGES;
4160         * diff_addremove/diff_change does not set the bit when
4161         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4162         */
4163        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4164                if (options->found_changes)
4165                        DIFF_OPT_SET(options, HAS_CHANGES);
4166                else
4167                        DIFF_OPT_CLR(options, HAS_CHANGES);
4168        }
4169}
4170
4171static void diffcore_apply_filter(const char *filter)
4172{
4173        int i;
4174        struct diff_queue_struct *q = &diff_queued_diff;
4175        struct diff_queue_struct outq;
4176        DIFF_QUEUE_CLEAR(&outq);
4177
4178        if (!filter)
4179                return;
4180
4181        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4182                int found;
4183                for (i = found = 0; !found && i < q->nr; i++) {
4184                        struct diff_filepair *p = q->queue[i];
4185                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4186                             ((p->score &&
4187                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4188                              (!p->score &&
4189                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4190                            ((p->status != DIFF_STATUS_MODIFIED) &&
4191                             strchr(filter, p->status)))
4192                                found++;
4193                }
4194                if (found)
4195                        return;
4196
4197                /* otherwise we will clear the whole queue
4198                 * by copying the empty outq at the end of this
4199                 * function, but first clear the current entries
4200                 * in the queue.
4201                 */
4202                for (i = 0; i < q->nr; i++)
4203                        diff_free_filepair(q->queue[i]);
4204        }
4205        else {
4206                /* Only the matching ones */
4207                for (i = 0; i < q->nr; i++) {
4208                        struct diff_filepair *p = q->queue[i];
4209
4210                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4211                             ((p->score &&
4212                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4213                              (!p->score &&
4214                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4215                            ((p->status != DIFF_STATUS_MODIFIED) &&
4216                             strchr(filter, p->status)))
4217                                diff_q(&outq, p);
4218                        else
4219                                diff_free_filepair(p);
4220                }
4221        }
4222        free(q->queue);
4223        *q = outq;
4224}
4225
4226/* Check whether two filespecs with the same mode and size are identical */
4227static int diff_filespec_is_identical(struct diff_filespec *one,
4228                                      struct diff_filespec *two)
4229{
4230        if (S_ISGITLINK(one->mode))
4231                return 0;
4232        if (diff_populate_filespec(one, 0))
4233                return 0;
4234        if (diff_populate_filespec(two, 0))
4235                return 0;
4236        return !memcmp(one->data, two->data, one->size);
4237}
4238
4239static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4240{
4241        int i;
4242        struct diff_queue_struct *q = &diff_queued_diff;
4243        struct diff_queue_struct outq;
4244        DIFF_QUEUE_CLEAR(&outq);
4245
4246        for (i = 0; i < q->nr; i++) {
4247                struct diff_filepair *p = q->queue[i];
4248
4249                /*
4250                 * 1. Entries that come from stat info dirtiness
4251                 *    always have both sides (iow, not create/delete),
4252                 *    one side of the object name is unknown, with
4253                 *    the same mode and size.  Keep the ones that
4254                 *    do not match these criteria.  They have real
4255                 *    differences.
4256                 *
4257                 * 2. At this point, the file is known to be modified,
4258                 *    with the same mode and size, and the object
4259                 *    name of one side is unknown.  Need to inspect
4260                 *    the identical contents.
4261                 */
4262                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4263                    !DIFF_FILE_VALID(p->two) ||
4264                    (p->one->sha1_valid && p->two->sha1_valid) ||
4265                    (p->one->mode != p->two->mode) ||
4266                    diff_populate_filespec(p->one, 1) ||
4267                    diff_populate_filespec(p->two, 1) ||
4268                    (p->one->size != p->two->size) ||
4269                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4270                        diff_q(&outq, p);
4271                else {
4272                        /*
4273                         * The caller can subtract 1 from skip_stat_unmatch
4274                         * to determine how many paths were dirty only
4275                         * due to stat info mismatch.
4276                         */
4277                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4278                                diffopt->skip_stat_unmatch++;
4279                        diff_free_filepair(p);
4280                }
4281        }
4282        free(q->queue);
4283        *q = outq;
4284}
4285
4286static int diffnamecmp(const void *a_, const void *b_)
4287{
4288        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4289        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4290        const char *name_a, *name_b;
4291
4292        name_a = a->one ? a->one->path : a->two->path;
4293        name_b = b->one ? b->one->path : b->two->path;
4294        return strcmp(name_a, name_b);
4295}
4296
4297void diffcore_fix_diff_index(struct diff_options *options)
4298{
4299        struct diff_queue_struct *q = &diff_queued_diff;
4300        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4301}
4302
4303void diffcore_std(struct diff_options *options)
4304{
4305        if (options->skip_stat_unmatch)
4306                diffcore_skip_stat_unmatch(options);
4307        if (!options->found_follow) {
4308                /* See try_to_follow_renames() in tree-diff.c */
4309                if (options->break_opt != -1)
4310                        diffcore_break(options->break_opt);
4311                if (options->detect_rename)
4312                        diffcore_rename(options);
4313                if (options->break_opt != -1)
4314                        diffcore_merge_broken();
4315        }
4316        if (options->pickaxe)
4317                diffcore_pickaxe(options);
4318        if (options->orderfile)
4319                diffcore_order(options->orderfile);
4320        if (!options->found_follow)
4321                /* See try_to_follow_renames() in tree-diff.c */
4322                diff_resolve_rename_copy();
4323        diffcore_apply_filter(options->filter);
4324
4325        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4326                DIFF_OPT_SET(options, HAS_CHANGES);
4327        else
4328                DIFF_OPT_CLR(options, HAS_CHANGES);
4329
4330        options->found_follow = 0;
4331}
4332
4333int diff_result_code(struct diff_options *opt, int status)
4334{
4335        int result = 0;
4336
4337        diff_warn_rename_limit("diff.renamelimit",
4338                               opt->needed_rename_limit,
4339                               opt->degraded_cc_to_c);
4340        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4341            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4342                return status;
4343        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4344            DIFF_OPT_TST(opt, HAS_CHANGES))
4345                result |= 01;
4346        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4347            DIFF_OPT_TST(opt, CHECK_FAILED))
4348                result |= 02;
4349        return result;
4350}
4351
4352/*
4353 * Shall changes to this submodule be ignored?
4354 *
4355 * Submodule changes can be configured to be ignored separately for each path,
4356 * but that configuration can be overridden from the command line.
4357 */
4358static int is_submodule_ignored(const char *path, struct diff_options *options)
4359{
4360        int ignored = 0;
4361        unsigned orig_flags = options->flags;
4362        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4363                set_diffopt_flags_from_submodule_config(options, path);
4364        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4365                ignored = 1;
4366        options->flags = orig_flags;
4367        return ignored;
4368}
4369
4370void diff_addremove(struct diff_options *options,
4371                    int addremove, unsigned mode,
4372                    const unsigned char *sha1,
4373                    const char *concatpath, unsigned dirty_submodule)
4374{
4375        struct diff_filespec *one, *two;
4376
4377        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4378                return;
4379
4380        /* This may look odd, but it is a preparation for
4381         * feeding "there are unchanged files which should
4382         * not produce diffs, but when you are doing copy
4383         * detection you would need them, so here they are"
4384         * entries to the diff-core.  They will be prefixed
4385         * with something like '=' or '*' (I haven't decided
4386         * which but should not make any difference).
4387         * Feeding the same new and old to diff_change()
4388         * also has the same effect.
4389         * Before the final output happens, they are pruned after
4390         * merged into rename/copy pairs as appropriate.
4391         */
4392        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4393                addremove = (addremove == '+' ? '-' :
4394                             addremove == '-' ? '+' : addremove);
4395
4396        if (options->prefix &&
4397            strncmp(concatpath, options->prefix, options->prefix_length))
4398                return;
4399
4400        one = alloc_filespec(concatpath);
4401        two = alloc_filespec(concatpath);
4402
4403        if (addremove != '+')
4404                fill_filespec(one, sha1, mode);
4405        if (addremove != '-') {
4406                fill_filespec(two, sha1, mode);
4407                two->dirty_submodule = dirty_submodule;
4408        }
4409
4410        diff_queue(&diff_queued_diff, one, two);
4411        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4412                DIFF_OPT_SET(options, HAS_CHANGES);
4413}
4414
4415void diff_change(struct diff_options *options,
4416                 unsigned old_mode, unsigned new_mode,
4417                 const unsigned char *old_sha1,
4418                 const unsigned char *new_sha1,
4419                 const char *concatpath,
4420                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4421{
4422        struct diff_filespec *one, *two;
4423
4424        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4425            is_submodule_ignored(concatpath, options))
4426                return;
4427
4428        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4429                unsigned tmp;
4430                const unsigned char *tmp_c;
4431                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4432                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4433                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4434                        new_dirty_submodule = tmp;
4435        }
4436
4437        if (options->prefix &&
4438            strncmp(concatpath, options->prefix, options->prefix_length))
4439                return;
4440
4441        one = alloc_filespec(concatpath);
4442        two = alloc_filespec(concatpath);
4443        fill_filespec(one, old_sha1, old_mode);
4444        fill_filespec(two, new_sha1, new_mode);
4445        one->dirty_submodule = old_dirty_submodule;
4446        two->dirty_submodule = new_dirty_submodule;
4447
4448        diff_queue(&diff_queued_diff, one, two);
4449        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4450                DIFF_OPT_SET(options, HAS_CHANGES);
4451}
4452
4453void diff_unmerge(struct diff_options *options,
4454                  const char *path,
4455                  unsigned mode, const unsigned char *sha1)
4456{
4457        struct diff_filespec *one, *two;
4458
4459        if (options->prefix &&
4460            strncmp(path, options->prefix, options->prefix_length))
4461                return;
4462
4463        one = alloc_filespec(path);
4464        two = alloc_filespec(path);
4465        fill_filespec(one, sha1, mode);
4466        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4467}
4468
4469static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4470                size_t *outsize)
4471{
4472        struct diff_tempfile *temp;
4473        const char *argv[3];
4474        const char **arg = argv;
4475        struct child_process child;
4476        struct strbuf buf = STRBUF_INIT;
4477        int err = 0;
4478
4479        temp = prepare_temp_file(spec->path, spec);
4480        *arg++ = pgm;
4481        *arg++ = temp->name;
4482        *arg = NULL;
4483
4484        memset(&child, 0, sizeof(child));
4485        child.use_shell = 1;
4486        child.argv = argv;
4487        child.out = -1;
4488        if (start_command(&child)) {
4489                remove_tempfile();
4490                return NULL;
4491        }
4492
4493        if (strbuf_read(&buf, child.out, 0) < 0)
4494                err = error("error reading from textconv command '%s'", pgm);
4495        close(child.out);
4496
4497        if (finish_command(&child) || err) {
4498                strbuf_release(&buf);
4499                remove_tempfile();
4500                return NULL;
4501        }
4502        remove_tempfile();
4503
4504        return strbuf_detach(&buf, outsize);
4505}
4506
4507size_t fill_textconv(struct userdiff_driver *driver,
4508                     struct diff_filespec *df,
4509                     char **outbuf)
4510{
4511        size_t size;
4512
4513        if (!driver || !driver->textconv) {
4514                if (!DIFF_FILE_VALID(df)) {
4515                        *outbuf = "";
4516                        return 0;
4517                }
4518                if (diff_populate_filespec(df, 0))
4519                        die("unable to read files to diff");
4520                *outbuf = df->data;
4521                return df->size;
4522        }
4523
4524        if (driver->textconv_cache && df->sha1_valid) {
4525                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4526                                          &size);
4527                if (*outbuf)
4528                        return size;
4529        }
4530
4531        *outbuf = run_textconv(driver->textconv, df, &size);
4532        if (!*outbuf)
4533                die("unable to read files to diff");
4534
4535        if (driver->textconv_cache && df->sha1_valid) {
4536                /* ignore errors, as we might be in a readonly repository */
4537                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4538                                size);
4539                /*
4540                 * we could save up changes and flush them all at the end,
4541                 * but we would need an extra call after all diffing is done.
4542                 * Since generating a cache entry is the slow path anyway,
4543                 * this extra overhead probably isn't a big deal.
4544                 */
4545                notes_cache_write(driver->textconv_cache);
4546        }
4547
4548        return size;
4549}