diff.con commit Document accumulated fixes since 1.7.9.2 (62ed072)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 400;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34static int diff_dirstat_permille_default = 30;
  35static struct diff_options default_diff_options;
  36
  37static char diff_colors[][COLOR_MAXLEN] = {
  38        GIT_COLOR_RESET,
  39        GIT_COLOR_NORMAL,       /* PLAIN */
  40        GIT_COLOR_BOLD,         /* METAINFO */
  41        GIT_COLOR_CYAN,         /* FRAGINFO */
  42        GIT_COLOR_RED,          /* OLD */
  43        GIT_COLOR_GREEN,        /* NEW */
  44        GIT_COLOR_YELLOW,       /* COMMIT */
  45        GIT_COLOR_BG_RED,       /* WHITESPACE */
  46        GIT_COLOR_NORMAL,       /* FUNCINFO */
  47};
  48
  49static int parse_diff_color_slot(const char *var, int ofs)
  50{
  51        if (!strcasecmp(var+ofs, "plain"))
  52                return DIFF_PLAIN;
  53        if (!strcasecmp(var+ofs, "meta"))
  54                return DIFF_METAINFO;
  55        if (!strcasecmp(var+ofs, "frag"))
  56                return DIFF_FRAGINFO;
  57        if (!strcasecmp(var+ofs, "old"))
  58                return DIFF_FILE_OLD;
  59        if (!strcasecmp(var+ofs, "new"))
  60                return DIFF_FILE_NEW;
  61        if (!strcasecmp(var+ofs, "commit"))
  62                return DIFF_COMMIT;
  63        if (!strcasecmp(var+ofs, "whitespace"))
  64                return DIFF_WHITESPACE;
  65        if (!strcasecmp(var+ofs, "func"))
  66                return DIFF_FUNCINFO;
  67        return -1;
  68}
  69
  70static int parse_dirstat_params(struct diff_options *options, const char *params,
  71                                struct strbuf *errmsg)
  72{
  73        const char *p = params;
  74        int p_len, ret = 0;
  75
  76        while (*p) {
  77                p_len = strchrnul(p, ',') - p;
  78                if (!memcmp(p, "changes", p_len)) {
  79                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  80                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  81                } else if (!memcmp(p, "lines", p_len)) {
  82                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  83                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  84                } else if (!memcmp(p, "files", p_len)) {
  85                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  86                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
  87                } else if (!memcmp(p, "noncumulative", p_len)) {
  88                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
  89                } else if (!memcmp(p, "cumulative", p_len)) {
  90                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
  91                } else if (isdigit(*p)) {
  92                        char *end;
  93                        int permille = strtoul(p, &end, 10) * 10;
  94                        if (*end == '.' && isdigit(*++end)) {
  95                                /* only use first digit */
  96                                permille += *end - '0';
  97                                /* .. and ignore any further digits */
  98                                while (isdigit(*++end))
  99                                        ; /* nothing */
 100                        }
 101                        if (end - p == p_len)
 102                                options->dirstat_permille = permille;
 103                        else {
 104                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%.*s'\n"),
 105                                            p_len, p);
 106                                ret++;
 107                        }
 108                } else {
 109                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%.*s'\n"),
 110                                    p_len, p);
 111                        ret++;
 112                }
 113
 114                p += p_len;
 115
 116                if (*p)
 117                        p++; /* more parameters, swallow separator */
 118        }
 119        return ret;
 120}
 121
 122static int git_config_rename(const char *var, const char *value)
 123{
 124        if (!value)
 125                return DIFF_DETECT_RENAME;
 126        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 127                return  DIFF_DETECT_COPY;
 128        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 129}
 130
 131/*
 132 * These are to give UI layer defaults.
 133 * The core-level commands such as git-diff-files should
 134 * never be affected by the setting of diff.renames
 135 * the user happens to have in the configuration file.
 136 */
 137int git_diff_ui_config(const char *var, const char *value, void *cb)
 138{
 139        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 140                diff_use_color_default = git_config_colorbool(var, value);
 141                return 0;
 142        }
 143        if (!strcmp(var, "diff.renames")) {
 144                diff_detect_rename_default = git_config_rename(var, value);
 145                return 0;
 146        }
 147        if (!strcmp(var, "diff.autorefreshindex")) {
 148                diff_auto_refresh_index = git_config_bool(var, value);
 149                return 0;
 150        }
 151        if (!strcmp(var, "diff.mnemonicprefix")) {
 152                diff_mnemonic_prefix = git_config_bool(var, value);
 153                return 0;
 154        }
 155        if (!strcmp(var, "diff.noprefix")) {
 156                diff_no_prefix = git_config_bool(var, value);
 157                return 0;
 158        }
 159        if (!strcmp(var, "diff.external"))
 160                return git_config_string(&external_diff_cmd_cfg, var, value);
 161        if (!strcmp(var, "diff.wordregex"))
 162                return git_config_string(&diff_word_regex_cfg, var, value);
 163
 164        if (!strcmp(var, "diff.ignoresubmodules"))
 165                handle_ignore_submodules_arg(&default_diff_options, value);
 166
 167        if (git_color_config(var, value, cb) < 0)
 168                return -1;
 169
 170        return git_diff_basic_config(var, value, cb);
 171}
 172
 173int git_diff_basic_config(const char *var, const char *value, void *cb)
 174{
 175        if (!strcmp(var, "diff.renamelimit")) {
 176                diff_rename_limit_default = git_config_int(var, value);
 177                return 0;
 178        }
 179
 180        switch (userdiff_config(var, value)) {
 181                case 0: break;
 182                case -1: return -1;
 183                default: return 0;
 184        }
 185
 186        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 187                int slot = parse_diff_color_slot(var, 11);
 188                if (slot < 0)
 189                        return 0;
 190                if (!value)
 191                        return config_error_nonbool(var);
 192                color_parse(value, var, diff_colors[slot]);
 193                return 0;
 194        }
 195
 196        /* like GNU diff's --suppress-blank-empty option  */
 197        if (!strcmp(var, "diff.suppressblankempty") ||
 198                        /* for backwards compatibility */
 199                        !strcmp(var, "diff.suppress-blank-empty")) {
 200                diff_suppress_blank_empty = git_config_bool(var, value);
 201                return 0;
 202        }
 203
 204        if (!strcmp(var, "diff.dirstat")) {
 205                struct strbuf errmsg = STRBUF_INIT;
 206                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 207                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 208                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 209                                errmsg.buf);
 210                strbuf_release(&errmsg);
 211                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 212                return 0;
 213        }
 214
 215        if (!prefixcmp(var, "submodule."))
 216                return parse_submodule_config_option(var, value);
 217
 218        return git_default_config(var, value, cb);
 219}
 220
 221static char *quote_two(const char *one, const char *two)
 222{
 223        int need_one = quote_c_style(one, NULL, NULL, 1);
 224        int need_two = quote_c_style(two, NULL, NULL, 1);
 225        struct strbuf res = STRBUF_INIT;
 226
 227        if (need_one + need_two) {
 228                strbuf_addch(&res, '"');
 229                quote_c_style(one, &res, NULL, 1);
 230                quote_c_style(two, &res, NULL, 1);
 231                strbuf_addch(&res, '"');
 232        } else {
 233                strbuf_addstr(&res, one);
 234                strbuf_addstr(&res, two);
 235        }
 236        return strbuf_detach(&res, NULL);
 237}
 238
 239static const char *external_diff(void)
 240{
 241        static const char *external_diff_cmd = NULL;
 242        static int done_preparing = 0;
 243
 244        if (done_preparing)
 245                return external_diff_cmd;
 246        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 247        if (!external_diff_cmd)
 248                external_diff_cmd = external_diff_cmd_cfg;
 249        done_preparing = 1;
 250        return external_diff_cmd;
 251}
 252
 253static struct diff_tempfile {
 254        const char *name; /* filename external diff should read from */
 255        char hex[41];
 256        char mode[10];
 257        char tmp_path[PATH_MAX];
 258} diff_temp[2];
 259
 260typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 261
 262struct emit_callback {
 263        int color_diff;
 264        unsigned ws_rule;
 265        int blank_at_eof_in_preimage;
 266        int blank_at_eof_in_postimage;
 267        int lno_in_preimage;
 268        int lno_in_postimage;
 269        sane_truncate_fn truncate;
 270        const char **label_path;
 271        struct diff_words_data *diff_words;
 272        struct diff_options *opt;
 273        int *found_changesp;
 274        struct strbuf *header;
 275};
 276
 277static int count_lines(const char *data, int size)
 278{
 279        int count, ch, completely_empty = 1, nl_just_seen = 0;
 280        count = 0;
 281        while (0 < size--) {
 282                ch = *data++;
 283                if (ch == '\n') {
 284                        count++;
 285                        nl_just_seen = 1;
 286                        completely_empty = 0;
 287                }
 288                else {
 289                        nl_just_seen = 0;
 290                        completely_empty = 0;
 291                }
 292        }
 293        if (completely_empty)
 294                return 0;
 295        if (!nl_just_seen)
 296                count++; /* no trailing newline */
 297        return count;
 298}
 299
 300static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 301{
 302        if (!DIFF_FILE_VALID(one)) {
 303                mf->ptr = (char *)""; /* does not matter */
 304                mf->size = 0;
 305                return 0;
 306        }
 307        else if (diff_populate_filespec(one, 0))
 308                return -1;
 309
 310        mf->ptr = one->data;
 311        mf->size = one->size;
 312        return 0;
 313}
 314
 315/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 316static unsigned long diff_filespec_size(struct diff_filespec *one)
 317{
 318        if (!DIFF_FILE_VALID(one))
 319                return 0;
 320        diff_populate_filespec(one, 1);
 321        return one->size;
 322}
 323
 324static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 325{
 326        char *ptr = mf->ptr;
 327        long size = mf->size;
 328        int cnt = 0;
 329
 330        if (!size)
 331                return cnt;
 332        ptr += size - 1; /* pointing at the very end */
 333        if (*ptr != '\n')
 334                ; /* incomplete line */
 335        else
 336                ptr--; /* skip the last LF */
 337        while (mf->ptr < ptr) {
 338                char *prev_eol;
 339                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 340                        if (*prev_eol == '\n')
 341                                break;
 342                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 343                        break;
 344                cnt++;
 345                ptr = prev_eol - 1;
 346        }
 347        return cnt;
 348}
 349
 350static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 351                               struct emit_callback *ecbdata)
 352{
 353        int l1, l2, at;
 354        unsigned ws_rule = ecbdata->ws_rule;
 355        l1 = count_trailing_blank(mf1, ws_rule);
 356        l2 = count_trailing_blank(mf2, ws_rule);
 357        if (l2 <= l1) {
 358                ecbdata->blank_at_eof_in_preimage = 0;
 359                ecbdata->blank_at_eof_in_postimage = 0;
 360                return;
 361        }
 362        at = count_lines(mf1->ptr, mf1->size);
 363        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 364
 365        at = count_lines(mf2->ptr, mf2->size);
 366        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 367}
 368
 369static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 370                        int first, const char *line, int len)
 371{
 372        int has_trailing_newline, has_trailing_carriage_return;
 373        int nofirst;
 374        FILE *file = o->file;
 375
 376        if (o->output_prefix) {
 377                struct strbuf *msg = NULL;
 378                msg = o->output_prefix(o, o->output_prefix_data);
 379                assert(msg);
 380                fwrite(msg->buf, msg->len, 1, file);
 381        }
 382
 383        if (len == 0) {
 384                has_trailing_newline = (first == '\n');
 385                has_trailing_carriage_return = (!has_trailing_newline &&
 386                                                (first == '\r'));
 387                nofirst = has_trailing_newline || has_trailing_carriage_return;
 388        } else {
 389                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 390                if (has_trailing_newline)
 391                        len--;
 392                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 393                if (has_trailing_carriage_return)
 394                        len--;
 395                nofirst = 0;
 396        }
 397
 398        if (len || !nofirst) {
 399                fputs(set, file);
 400                if (!nofirst)
 401                        fputc(first, file);
 402                fwrite(line, len, 1, file);
 403                fputs(reset, file);
 404        }
 405        if (has_trailing_carriage_return)
 406                fputc('\r', file);
 407        if (has_trailing_newline)
 408                fputc('\n', file);
 409}
 410
 411static void emit_line(struct diff_options *o, const char *set, const char *reset,
 412                      const char *line, int len)
 413{
 414        emit_line_0(o, set, reset, line[0], line+1, len-1);
 415}
 416
 417static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 418{
 419        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 420              ecbdata->blank_at_eof_in_preimage &&
 421              ecbdata->blank_at_eof_in_postimage &&
 422              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 423              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 424                return 0;
 425        return ws_blank_line(line, len, ecbdata->ws_rule);
 426}
 427
 428static void emit_add_line(const char *reset,
 429                          struct emit_callback *ecbdata,
 430                          const char *line, int len)
 431{
 432        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 433        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 434
 435        if (!*ws)
 436                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 437        else if (new_blank_line_at_eof(ecbdata, line, len))
 438                /* Blank line at EOF - paint '+' as well */
 439                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 440        else {
 441                /* Emit just the prefix, then the rest. */
 442                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 443                ws_check_emit(line, len, ecbdata->ws_rule,
 444                              ecbdata->opt->file, set, reset, ws);
 445        }
 446}
 447
 448static void emit_hunk_header(struct emit_callback *ecbdata,
 449                             const char *line, int len)
 450{
 451        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 452        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 453        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 454        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 455        static const char atat[2] = { '@', '@' };
 456        const char *cp, *ep;
 457        struct strbuf msgbuf = STRBUF_INIT;
 458        int org_len = len;
 459        int i = 1;
 460
 461        /*
 462         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 463         * it always is at least 10 bytes long.
 464         */
 465        if (len < 10 ||
 466            memcmp(line, atat, 2) ||
 467            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 468                emit_line(ecbdata->opt, plain, reset, line, len);
 469                return;
 470        }
 471        ep += 2; /* skip over @@ */
 472
 473        /* The hunk header in fraginfo color */
 474        strbuf_add(&msgbuf, frag, strlen(frag));
 475        strbuf_add(&msgbuf, line, ep - line);
 476        strbuf_add(&msgbuf, reset, strlen(reset));
 477
 478        /*
 479         * trailing "\r\n"
 480         */
 481        for ( ; i < 3; i++)
 482                if (line[len - i] == '\r' || line[len - i] == '\n')
 483                        len--;
 484
 485        /* blank before the func header */
 486        for (cp = ep; ep - line < len; ep++)
 487                if (*ep != ' ' && *ep != '\t')
 488                        break;
 489        if (ep != cp) {
 490                strbuf_add(&msgbuf, plain, strlen(plain));
 491                strbuf_add(&msgbuf, cp, ep - cp);
 492                strbuf_add(&msgbuf, reset, strlen(reset));
 493        }
 494
 495        if (ep < line + len) {
 496                strbuf_add(&msgbuf, func, strlen(func));
 497                strbuf_add(&msgbuf, ep, line + len - ep);
 498                strbuf_add(&msgbuf, reset, strlen(reset));
 499        }
 500
 501        strbuf_add(&msgbuf, line + len, org_len - len);
 502        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 503        strbuf_release(&msgbuf);
 504}
 505
 506static struct diff_tempfile *claim_diff_tempfile(void) {
 507        int i;
 508        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 509                if (!diff_temp[i].name)
 510                        return diff_temp + i;
 511        die("BUG: diff is failing to clean up its tempfiles");
 512}
 513
 514static int remove_tempfile_installed;
 515
 516static void remove_tempfile(void)
 517{
 518        int i;
 519        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 520                if (diff_temp[i].name == diff_temp[i].tmp_path)
 521                        unlink_or_warn(diff_temp[i].name);
 522                diff_temp[i].name = NULL;
 523        }
 524}
 525
 526static void remove_tempfile_on_signal(int signo)
 527{
 528        remove_tempfile();
 529        sigchain_pop(signo);
 530        raise(signo);
 531}
 532
 533static void print_line_count(FILE *file, int count)
 534{
 535        switch (count) {
 536        case 0:
 537                fprintf(file, "0,0");
 538                break;
 539        case 1:
 540                fprintf(file, "1");
 541                break;
 542        default:
 543                fprintf(file, "1,%d", count);
 544                break;
 545        }
 546}
 547
 548static void emit_rewrite_lines(struct emit_callback *ecb,
 549                               int prefix, const char *data, int size)
 550{
 551        const char *endp = NULL;
 552        static const char *nneof = " No newline at end of file\n";
 553        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 554        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 555
 556        while (0 < size) {
 557                int len;
 558
 559                endp = memchr(data, '\n', size);
 560                len = endp ? (endp - data + 1) : size;
 561                if (prefix != '+') {
 562                        ecb->lno_in_preimage++;
 563                        emit_line_0(ecb->opt, old, reset, '-',
 564                                    data, len);
 565                } else {
 566                        ecb->lno_in_postimage++;
 567                        emit_add_line(reset, ecb, data, len);
 568                }
 569                size -= len;
 570                data += len;
 571        }
 572        if (!endp) {
 573                const char *plain = diff_get_color(ecb->color_diff,
 574                                                   DIFF_PLAIN);
 575                emit_line_0(ecb->opt, plain, reset, '\\',
 576                            nneof, strlen(nneof));
 577        }
 578}
 579
 580static void emit_rewrite_diff(const char *name_a,
 581                              const char *name_b,
 582                              struct diff_filespec *one,
 583                              struct diff_filespec *two,
 584                              struct userdiff_driver *textconv_one,
 585                              struct userdiff_driver *textconv_two,
 586                              struct diff_options *o)
 587{
 588        int lc_a, lc_b;
 589        const char *name_a_tab, *name_b_tab;
 590        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 591        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 592        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 593        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 594        const char *a_prefix, *b_prefix;
 595        char *data_one, *data_two;
 596        size_t size_one, size_two;
 597        struct emit_callback ecbdata;
 598        char *line_prefix = "";
 599        struct strbuf *msgbuf;
 600
 601        if (o && o->output_prefix) {
 602                msgbuf = o->output_prefix(o, o->output_prefix_data);
 603                line_prefix = msgbuf->buf;
 604        }
 605
 606        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 607                a_prefix = o->b_prefix;
 608                b_prefix = o->a_prefix;
 609        } else {
 610                a_prefix = o->a_prefix;
 611                b_prefix = o->b_prefix;
 612        }
 613
 614        name_a += (*name_a == '/');
 615        name_b += (*name_b == '/');
 616        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 617        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 618
 619        strbuf_reset(&a_name);
 620        strbuf_reset(&b_name);
 621        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 622        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 623
 624        size_one = fill_textconv(textconv_one, one, &data_one);
 625        size_two = fill_textconv(textconv_two, two, &data_two);
 626
 627        memset(&ecbdata, 0, sizeof(ecbdata));
 628        ecbdata.color_diff = want_color(o->use_color);
 629        ecbdata.found_changesp = &o->found_changes;
 630        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 631        ecbdata.opt = o;
 632        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 633                mmfile_t mf1, mf2;
 634                mf1.ptr = (char *)data_one;
 635                mf2.ptr = (char *)data_two;
 636                mf1.size = size_one;
 637                mf2.size = size_two;
 638                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 639        }
 640        ecbdata.lno_in_preimage = 1;
 641        ecbdata.lno_in_postimage = 1;
 642
 643        lc_a = count_lines(data_one, size_one);
 644        lc_b = count_lines(data_two, size_two);
 645        fprintf(o->file,
 646                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 647                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 648                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 649                line_prefix, fraginfo);
 650        if (!o->irreversible_delete)
 651                print_line_count(o->file, lc_a);
 652        else
 653                fprintf(o->file, "?,?");
 654        fprintf(o->file, " +");
 655        print_line_count(o->file, lc_b);
 656        fprintf(o->file, " @@%s\n", reset);
 657        if (lc_a && !o->irreversible_delete)
 658                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 659        if (lc_b)
 660                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 661        if (textconv_one)
 662                free((char *)data_one);
 663        if (textconv_two)
 664                free((char *)data_two);
 665}
 666
 667struct diff_words_buffer {
 668        mmfile_t text;
 669        long alloc;
 670        struct diff_words_orig {
 671                const char *begin, *end;
 672        } *orig;
 673        int orig_nr, orig_alloc;
 674};
 675
 676static void diff_words_append(char *line, unsigned long len,
 677                struct diff_words_buffer *buffer)
 678{
 679        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 680        line++;
 681        len--;
 682        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 683        buffer->text.size += len;
 684        buffer->text.ptr[buffer->text.size] = '\0';
 685}
 686
 687struct diff_words_style_elem {
 688        const char *prefix;
 689        const char *suffix;
 690        const char *color; /* NULL; filled in by the setup code if
 691                            * color is enabled */
 692};
 693
 694struct diff_words_style {
 695        enum diff_words_type type;
 696        struct diff_words_style_elem new, old, ctx;
 697        const char *newline;
 698};
 699
 700static struct diff_words_style diff_words_styles[] = {
 701        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 702        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 703        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 704};
 705
 706struct diff_words_data {
 707        struct diff_words_buffer minus, plus;
 708        const char *current_plus;
 709        int last_minus;
 710        struct diff_options *opt;
 711        regex_t *word_regex;
 712        enum diff_words_type type;
 713        struct diff_words_style *style;
 714};
 715
 716static int fn_out_diff_words_write_helper(FILE *fp,
 717                                          struct diff_words_style_elem *st_el,
 718                                          const char *newline,
 719                                          size_t count, const char *buf,
 720                                          const char *line_prefix)
 721{
 722        int print = 0;
 723
 724        while (count) {
 725                char *p = memchr(buf, '\n', count);
 726                if (print)
 727                        fputs(line_prefix, fp);
 728                if (p != buf) {
 729                        if (st_el->color && fputs(st_el->color, fp) < 0)
 730                                return -1;
 731                        if (fputs(st_el->prefix, fp) < 0 ||
 732                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 733                            fputs(st_el->suffix, fp) < 0)
 734                                return -1;
 735                        if (st_el->color && *st_el->color
 736                            && fputs(GIT_COLOR_RESET, fp) < 0)
 737                                return -1;
 738                }
 739                if (!p)
 740                        return 0;
 741                if (fputs(newline, fp) < 0)
 742                        return -1;
 743                count -= p + 1 - buf;
 744                buf = p + 1;
 745                print = 1;
 746        }
 747        return 0;
 748}
 749
 750/*
 751 * '--color-words' algorithm can be described as:
 752 *
 753 *   1. collect a the minus/plus lines of a diff hunk, divided into
 754 *      minus-lines and plus-lines;
 755 *
 756 *   2. break both minus-lines and plus-lines into words and
 757 *      place them into two mmfile_t with one word for each line;
 758 *
 759 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 760 *
 761 * And for the common parts of the both file, we output the plus side text.
 762 * diff_words->current_plus is used to trace the current position of the plus file
 763 * which printed. diff_words->last_minus is used to trace the last minus word
 764 * printed.
 765 *
 766 * For '--graph' to work with '--color-words', we need to output the graph prefix
 767 * on each line of color words output. Generally, there are two conditions on
 768 * which we should output the prefix.
 769 *
 770 *   1. diff_words->last_minus == 0 &&
 771 *      diff_words->current_plus == diff_words->plus.text.ptr
 772 *
 773 *      that is: the plus text must start as a new line, and if there is no minus
 774 *      word printed, a graph prefix must be printed.
 775 *
 776 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 777 *      *(diff_words->current_plus - 1) == '\n'
 778 *
 779 *      that is: a graph prefix must be printed following a '\n'
 780 */
 781static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 782{
 783        if ((diff_words->last_minus == 0 &&
 784                diff_words->current_plus == diff_words->plus.text.ptr) ||
 785                (diff_words->current_plus > diff_words->plus.text.ptr &&
 786                *(diff_words->current_plus - 1) == '\n')) {
 787                return 1;
 788        } else {
 789                return 0;
 790        }
 791}
 792
 793static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 794{
 795        struct diff_words_data *diff_words = priv;
 796        struct diff_words_style *style = diff_words->style;
 797        int minus_first, minus_len, plus_first, plus_len;
 798        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 799        struct diff_options *opt = diff_words->opt;
 800        struct strbuf *msgbuf;
 801        char *line_prefix = "";
 802
 803        if (line[0] != '@' || parse_hunk_header(line, len,
 804                        &minus_first, &minus_len, &plus_first, &plus_len))
 805                return;
 806
 807        assert(opt);
 808        if (opt->output_prefix) {
 809                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 810                line_prefix = msgbuf->buf;
 811        }
 812
 813        /* POSIX requires that first be decremented by one if len == 0... */
 814        if (minus_len) {
 815                minus_begin = diff_words->minus.orig[minus_first].begin;
 816                minus_end =
 817                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 818        } else
 819                minus_begin = minus_end =
 820                        diff_words->minus.orig[minus_first].end;
 821
 822        if (plus_len) {
 823                plus_begin = diff_words->plus.orig[plus_first].begin;
 824                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 825        } else
 826                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 827
 828        if (color_words_output_graph_prefix(diff_words)) {
 829                fputs(line_prefix, diff_words->opt->file);
 830        }
 831        if (diff_words->current_plus != plus_begin) {
 832                fn_out_diff_words_write_helper(diff_words->opt->file,
 833                                &style->ctx, style->newline,
 834                                plus_begin - diff_words->current_plus,
 835                                diff_words->current_plus, line_prefix);
 836                if (*(plus_begin - 1) == '\n')
 837                        fputs(line_prefix, diff_words->opt->file);
 838        }
 839        if (minus_begin != minus_end) {
 840                fn_out_diff_words_write_helper(diff_words->opt->file,
 841                                &style->old, style->newline,
 842                                minus_end - minus_begin, minus_begin,
 843                                line_prefix);
 844        }
 845        if (plus_begin != plus_end) {
 846                fn_out_diff_words_write_helper(diff_words->opt->file,
 847                                &style->new, style->newline,
 848                                plus_end - plus_begin, plus_begin,
 849                                line_prefix);
 850        }
 851
 852        diff_words->current_plus = plus_end;
 853        diff_words->last_minus = minus_first;
 854}
 855
 856/* This function starts looking at *begin, and returns 0 iff a word was found. */
 857static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 858                int *begin, int *end)
 859{
 860        if (word_regex && *begin < buffer->size) {
 861                regmatch_t match[1];
 862                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 863                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 864                                        '\n', match[0].rm_eo - match[0].rm_so);
 865                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 866                        *begin += match[0].rm_so;
 867                        return *begin >= *end;
 868                }
 869                return -1;
 870        }
 871
 872        /* find the next word */
 873        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 874                (*begin)++;
 875        if (*begin >= buffer->size)
 876                return -1;
 877
 878        /* find the end of the word */
 879        *end = *begin + 1;
 880        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 881                (*end)++;
 882
 883        return 0;
 884}
 885
 886/*
 887 * This function splits the words in buffer->text, stores the list with
 888 * newline separator into out, and saves the offsets of the original words
 889 * in buffer->orig.
 890 */
 891static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 892                regex_t *word_regex)
 893{
 894        int i, j;
 895        long alloc = 0;
 896
 897        out->size = 0;
 898        out->ptr = NULL;
 899
 900        /* fake an empty "0th" word */
 901        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 902        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 903        buffer->orig_nr = 1;
 904
 905        for (i = 0; i < buffer->text.size; i++) {
 906                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 907                        return;
 908
 909                /* store original boundaries */
 910                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 911                                buffer->orig_alloc);
 912                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 913                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 914                buffer->orig_nr++;
 915
 916                /* store one word */
 917                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 918                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 919                out->ptr[out->size + j - i] = '\n';
 920                out->size += j - i + 1;
 921
 922                i = j - 1;
 923        }
 924}
 925
 926/* this executes the word diff on the accumulated buffers */
 927static void diff_words_show(struct diff_words_data *diff_words)
 928{
 929        xpparam_t xpp;
 930        xdemitconf_t xecfg;
 931        mmfile_t minus, plus;
 932        struct diff_words_style *style = diff_words->style;
 933
 934        struct diff_options *opt = diff_words->opt;
 935        struct strbuf *msgbuf;
 936        char *line_prefix = "";
 937
 938        assert(opt);
 939        if (opt->output_prefix) {
 940                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 941                line_prefix = msgbuf->buf;
 942        }
 943
 944        /* special case: only removal */
 945        if (!diff_words->plus.text.size) {
 946                fputs(line_prefix, diff_words->opt->file);
 947                fn_out_diff_words_write_helper(diff_words->opt->file,
 948                        &style->old, style->newline,
 949                        diff_words->minus.text.size,
 950                        diff_words->minus.text.ptr, line_prefix);
 951                diff_words->minus.text.size = 0;
 952                return;
 953        }
 954
 955        diff_words->current_plus = diff_words->plus.text.ptr;
 956        diff_words->last_minus = 0;
 957
 958        memset(&xpp, 0, sizeof(xpp));
 959        memset(&xecfg, 0, sizeof(xecfg));
 960        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 961        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 962        xpp.flags = 0;
 963        /* as only the hunk header will be parsed, we need a 0-context */
 964        xecfg.ctxlen = 0;
 965        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 966                      &xpp, &xecfg);
 967        free(minus.ptr);
 968        free(plus.ptr);
 969        if (diff_words->current_plus != diff_words->plus.text.ptr +
 970                        diff_words->plus.text.size) {
 971                if (color_words_output_graph_prefix(diff_words))
 972                        fputs(line_prefix, diff_words->opt->file);
 973                fn_out_diff_words_write_helper(diff_words->opt->file,
 974                        &style->ctx, style->newline,
 975                        diff_words->plus.text.ptr + diff_words->plus.text.size
 976                        - diff_words->current_plus, diff_words->current_plus,
 977                        line_prefix);
 978        }
 979        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 980}
 981
 982/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 983static void diff_words_flush(struct emit_callback *ecbdata)
 984{
 985        if (ecbdata->diff_words->minus.text.size ||
 986            ecbdata->diff_words->plus.text.size)
 987                diff_words_show(ecbdata->diff_words);
 988}
 989
 990static void free_diff_words_data(struct emit_callback *ecbdata)
 991{
 992        if (ecbdata->diff_words) {
 993                diff_words_flush(ecbdata);
 994                free (ecbdata->diff_words->minus.text.ptr);
 995                free (ecbdata->diff_words->minus.orig);
 996                free (ecbdata->diff_words->plus.text.ptr);
 997                free (ecbdata->diff_words->plus.orig);
 998                if (ecbdata->diff_words->word_regex) {
 999                        regfree(ecbdata->diff_words->word_regex);
1000                        free(ecbdata->diff_words->word_regex);
1001                }
1002                free(ecbdata->diff_words);
1003                ecbdata->diff_words = NULL;
1004        }
1005}
1006
1007const char *diff_get_color(int diff_use_color, enum color_diff ix)
1008{
1009        if (want_color(diff_use_color))
1010                return diff_colors[ix];
1011        return "";
1012}
1013
1014static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1015{
1016        const char *cp;
1017        unsigned long allot;
1018        size_t l = len;
1019
1020        if (ecb->truncate)
1021                return ecb->truncate(line, len);
1022        cp = line;
1023        allot = l;
1024        while (0 < l) {
1025                (void) utf8_width(&cp, &l);
1026                if (!cp)
1027                        break; /* truncated in the middle? */
1028        }
1029        return allot - l;
1030}
1031
1032static void find_lno(const char *line, struct emit_callback *ecbdata)
1033{
1034        const char *p;
1035        ecbdata->lno_in_preimage = 0;
1036        ecbdata->lno_in_postimage = 0;
1037        p = strchr(line, '-');
1038        if (!p)
1039                return; /* cannot happen */
1040        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1041        p = strchr(p, '+');
1042        if (!p)
1043                return; /* cannot happen */
1044        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1045}
1046
1047static void fn_out_consume(void *priv, char *line, unsigned long len)
1048{
1049        struct emit_callback *ecbdata = priv;
1050        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1051        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
1052        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1053        struct diff_options *o = ecbdata->opt;
1054        char *line_prefix = "";
1055        struct strbuf *msgbuf;
1056
1057        if (o && o->output_prefix) {
1058                msgbuf = o->output_prefix(o, o->output_prefix_data);
1059                line_prefix = msgbuf->buf;
1060        }
1061
1062        if (ecbdata->header) {
1063                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
1064                strbuf_reset(ecbdata->header);
1065                ecbdata->header = NULL;
1066        }
1067        *(ecbdata->found_changesp) = 1;
1068
1069        if (ecbdata->label_path[0]) {
1070                const char *name_a_tab, *name_b_tab;
1071
1072                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1073                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1074
1075                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
1076                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1077                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
1078                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1079                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1080        }
1081
1082        if (diff_suppress_blank_empty
1083            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1084                line[0] = '\n';
1085                len = 1;
1086        }
1087
1088        if (line[0] == '@') {
1089                if (ecbdata->diff_words)
1090                        diff_words_flush(ecbdata);
1091                len = sane_truncate_line(ecbdata, line, len);
1092                find_lno(line, ecbdata);
1093                emit_hunk_header(ecbdata, line, len);
1094                if (line[len-1] != '\n')
1095                        putc('\n', ecbdata->opt->file);
1096                return;
1097        }
1098
1099        if (len < 1) {
1100                emit_line(ecbdata->opt, reset, reset, line, len);
1101                if (ecbdata->diff_words
1102                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1103                        fputs("~\n", ecbdata->opt->file);
1104                return;
1105        }
1106
1107        if (ecbdata->diff_words) {
1108                if (line[0] == '-') {
1109                        diff_words_append(line, len,
1110                                          &ecbdata->diff_words->minus);
1111                        return;
1112                } else if (line[0] == '+') {
1113                        diff_words_append(line, len,
1114                                          &ecbdata->diff_words->plus);
1115                        return;
1116                } else if (!prefixcmp(line, "\\ ")) {
1117                        /*
1118                         * Eat the "no newline at eof" marker as if we
1119                         * saw a "+" or "-" line with nothing on it,
1120                         * and return without diff_words_flush() to
1121                         * defer processing. If this is the end of
1122                         * preimage, more "+" lines may come after it.
1123                         */
1124                        return;
1125                }
1126                diff_words_flush(ecbdata);
1127                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1128                        emit_line(ecbdata->opt, plain, reset, line, len);
1129                        fputs("~\n", ecbdata->opt->file);
1130                } else {
1131                        /*
1132                         * Skip the prefix character, if any.  With
1133                         * diff_suppress_blank_empty, there may be
1134                         * none.
1135                         */
1136                        if (line[0] != '\n') {
1137                              line++;
1138                              len--;
1139                        }
1140                        emit_line(ecbdata->opt, plain, reset, line, len);
1141                }
1142                return;
1143        }
1144
1145        if (line[0] != '+') {
1146                const char *color =
1147                        diff_get_color(ecbdata->color_diff,
1148                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1149                ecbdata->lno_in_preimage++;
1150                if (line[0] == ' ')
1151                        ecbdata->lno_in_postimage++;
1152                emit_line(ecbdata->opt, color, reset, line, len);
1153        } else {
1154                ecbdata->lno_in_postimage++;
1155                emit_add_line(reset, ecbdata, line + 1, len - 1);
1156        }
1157}
1158
1159static char *pprint_rename(const char *a, const char *b)
1160{
1161        const char *old = a;
1162        const char *new = b;
1163        struct strbuf name = STRBUF_INIT;
1164        int pfx_length, sfx_length;
1165        int len_a = strlen(a);
1166        int len_b = strlen(b);
1167        int a_midlen, b_midlen;
1168        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1169        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1170
1171        if (qlen_a || qlen_b) {
1172                quote_c_style(a, &name, NULL, 0);
1173                strbuf_addstr(&name, " => ");
1174                quote_c_style(b, &name, NULL, 0);
1175                return strbuf_detach(&name, NULL);
1176        }
1177
1178        /* Find common prefix */
1179        pfx_length = 0;
1180        while (*old && *new && *old == *new) {
1181                if (*old == '/')
1182                        pfx_length = old - a + 1;
1183                old++;
1184                new++;
1185        }
1186
1187        /* Find common suffix */
1188        old = a + len_a;
1189        new = b + len_b;
1190        sfx_length = 0;
1191        while (a <= old && b <= new && *old == *new) {
1192                if (*old == '/')
1193                        sfx_length = len_a - (old - a);
1194                old--;
1195                new--;
1196        }
1197
1198        /*
1199         * pfx{mid-a => mid-b}sfx
1200         * {pfx-a => pfx-b}sfx
1201         * pfx{sfx-a => sfx-b}
1202         * name-a => name-b
1203         */
1204        a_midlen = len_a - pfx_length - sfx_length;
1205        b_midlen = len_b - pfx_length - sfx_length;
1206        if (a_midlen < 0)
1207                a_midlen = 0;
1208        if (b_midlen < 0)
1209                b_midlen = 0;
1210
1211        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1212        if (pfx_length + sfx_length) {
1213                strbuf_add(&name, a, pfx_length);
1214                strbuf_addch(&name, '{');
1215        }
1216        strbuf_add(&name, a + pfx_length, a_midlen);
1217        strbuf_addstr(&name, " => ");
1218        strbuf_add(&name, b + pfx_length, b_midlen);
1219        if (pfx_length + sfx_length) {
1220                strbuf_addch(&name, '}');
1221                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1222        }
1223        return strbuf_detach(&name, NULL);
1224}
1225
1226struct diffstat_t {
1227        int nr;
1228        int alloc;
1229        struct diffstat_file {
1230                char *from_name;
1231                char *name;
1232                char *print_name;
1233                unsigned is_unmerged:1;
1234                unsigned is_binary:1;
1235                unsigned is_renamed:1;
1236                uintmax_t added, deleted;
1237        } **files;
1238};
1239
1240static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1241                                          const char *name_a,
1242                                          const char *name_b)
1243{
1244        struct diffstat_file *x;
1245        x = xcalloc(sizeof (*x), 1);
1246        if (diffstat->nr == diffstat->alloc) {
1247                diffstat->alloc = alloc_nr(diffstat->alloc);
1248                diffstat->files = xrealloc(diffstat->files,
1249                                diffstat->alloc * sizeof(x));
1250        }
1251        diffstat->files[diffstat->nr++] = x;
1252        if (name_b) {
1253                x->from_name = xstrdup(name_a);
1254                x->name = xstrdup(name_b);
1255                x->is_renamed = 1;
1256        }
1257        else {
1258                x->from_name = NULL;
1259                x->name = xstrdup(name_a);
1260        }
1261        return x;
1262}
1263
1264static void diffstat_consume(void *priv, char *line, unsigned long len)
1265{
1266        struct diffstat_t *diffstat = priv;
1267        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1268
1269        if (line[0] == '+')
1270                x->added++;
1271        else if (line[0] == '-')
1272                x->deleted++;
1273}
1274
1275const char mime_boundary_leader[] = "------------";
1276
1277static int scale_linear(int it, int width, int max_change)
1278{
1279        if (!it)
1280                return 0;
1281        /*
1282         * make sure that at least one '-' or '+' is printed if
1283         * there is any change to this path. The easiest way is to
1284         * scale linearly as if the alloted width is one column shorter
1285         * than it is, and then add 1 to the result.
1286         */
1287        return 1 + (it * (width - 1) / max_change);
1288}
1289
1290static void show_name(FILE *file,
1291                      const char *prefix, const char *name, int len)
1292{
1293        fprintf(file, " %s%-*s |", prefix, len, name);
1294}
1295
1296static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1297{
1298        if (cnt <= 0)
1299                return;
1300        fprintf(file, "%s", set);
1301        while (cnt--)
1302                putc(ch, file);
1303        fprintf(file, "%s", reset);
1304}
1305
1306static void fill_print_name(struct diffstat_file *file)
1307{
1308        char *pname;
1309
1310        if (file->print_name)
1311                return;
1312
1313        if (!file->is_renamed) {
1314                struct strbuf buf = STRBUF_INIT;
1315                if (quote_c_style(file->name, &buf, NULL, 0)) {
1316                        pname = strbuf_detach(&buf, NULL);
1317                } else {
1318                        pname = file->name;
1319                        strbuf_release(&buf);
1320                }
1321        } else {
1322                pname = pprint_rename(file->from_name, file->name);
1323        }
1324        file->print_name = pname;
1325}
1326
1327int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1328{
1329        struct strbuf sb = STRBUF_INIT;
1330        int ret;
1331
1332        if (!files) {
1333                assert(insertions == 0 && deletions == 0);
1334                return fputs(_(" 0 files changed\n"), fp);
1335        }
1336
1337        strbuf_addf(&sb,
1338                    Q_(" %d file changed", " %d files changed", files),
1339                    files);
1340
1341        /*
1342         * For binary diff, the caller may want to print "x files
1343         * changed" with insertions == 0 && deletions == 0.
1344         *
1345         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1346         * is probably less confusing (i.e skip over "2 files changed
1347         * but nothing about added/removed lines? Is this a bug in Git?").
1348         */
1349        if (insertions || deletions == 0) {
1350                /*
1351                 * TRANSLATORS: "+" in (+) is a line addition marker;
1352                 * do not translate it.
1353                 */
1354                strbuf_addf(&sb,
1355                            Q_(", %d insertion(+)", ", %d insertions(+)",
1356                               insertions),
1357                            insertions);
1358        }
1359
1360        if (deletions || insertions == 0) {
1361                /*
1362                 * TRANSLATORS: "-" in (-) is a line removal marker;
1363                 * do not translate it.
1364                 */
1365                strbuf_addf(&sb,
1366                            Q_(", %d deletion(-)", ", %d deletions(-)",
1367                               deletions),
1368                            deletions);
1369        }
1370        strbuf_addch(&sb, '\n');
1371        ret = fputs(sb.buf, fp);
1372        strbuf_release(&sb);
1373        return ret;
1374}
1375
1376static void show_stats(struct diffstat_t *data, struct diff_options *options)
1377{
1378        int i, len, add, del, adds = 0, dels = 0;
1379        uintmax_t max_change = 0, max_len = 0;
1380        int total_files = data->nr;
1381        int width, name_width, count;
1382        const char *reset, *add_c, *del_c;
1383        const char *line_prefix = "";
1384        int extra_shown = 0;
1385        struct strbuf *msg = NULL;
1386
1387        if (data->nr == 0)
1388                return;
1389
1390        if (options->output_prefix) {
1391                msg = options->output_prefix(options, options->output_prefix_data);
1392                line_prefix = msg->buf;
1393        }
1394
1395        width = options->stat_width ? options->stat_width : 80;
1396        name_width = options->stat_name_width ? options->stat_name_width : 50;
1397        count = options->stat_count ? options->stat_count : data->nr;
1398
1399        /* Sanity: give at least 5 columns to the graph,
1400         * but leave at least 10 columns for the name.
1401         */
1402        if (width < 25)
1403                width = 25;
1404        if (name_width < 10)
1405                name_width = 10;
1406        else if (width < name_width + 15)
1407                name_width = width - 15;
1408
1409        /* Find the longest filename and max number of changes */
1410        reset = diff_get_color_opt(options, DIFF_RESET);
1411        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1412        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1413
1414        for (i = 0; (i < count) && (i < data->nr); i++) {
1415                struct diffstat_file *file = data->files[i];
1416                uintmax_t change = file->added + file->deleted;
1417                if (!data->files[i]->is_renamed &&
1418                         (change == 0)) {
1419                        count++; /* not shown == room for one more */
1420                        continue;
1421                }
1422                fill_print_name(file);
1423                len = strlen(file->print_name);
1424                if (max_len < len)
1425                        max_len = len;
1426
1427                if (file->is_binary || file->is_unmerged)
1428                        continue;
1429                if (max_change < change)
1430                        max_change = change;
1431        }
1432        count = i; /* min(count, data->nr) */
1433
1434        /* Compute the width of the graph part;
1435         * 10 is for one blank at the beginning of the line plus
1436         * " | count " between the name and the graph.
1437         *
1438         * From here on, name_width is the width of the name area,
1439         * and width is the width of the graph area.
1440         */
1441        name_width = (name_width < max_len) ? name_width : max_len;
1442        if (width < (name_width + 10) + max_change)
1443                width = width - (name_width + 10);
1444        else
1445                width = max_change;
1446
1447        for (i = 0; i < count; i++) {
1448                const char *prefix = "";
1449                char *name = data->files[i]->print_name;
1450                uintmax_t added = data->files[i]->added;
1451                uintmax_t deleted = data->files[i]->deleted;
1452                int name_len;
1453
1454                if (!data->files[i]->is_renamed &&
1455                         (added + deleted == 0)) {
1456                        total_files--;
1457                        continue;
1458                }
1459                /*
1460                 * "scale" the filename
1461                 */
1462                len = name_width;
1463                name_len = strlen(name);
1464                if (name_width < name_len) {
1465                        char *slash;
1466                        prefix = "...";
1467                        len -= 3;
1468                        name += name_len - len;
1469                        slash = strchr(name, '/');
1470                        if (slash)
1471                                name = slash;
1472                }
1473
1474                if (data->files[i]->is_binary) {
1475                        fprintf(options->file, "%s", line_prefix);
1476                        show_name(options->file, prefix, name, len);
1477                        fprintf(options->file, "  Bin ");
1478                        fprintf(options->file, "%s%"PRIuMAX"%s",
1479                                del_c, deleted, reset);
1480                        fprintf(options->file, " -> ");
1481                        fprintf(options->file, "%s%"PRIuMAX"%s",
1482                                add_c, added, reset);
1483                        fprintf(options->file, " bytes");
1484                        fprintf(options->file, "\n");
1485                        continue;
1486                }
1487                else if (data->files[i]->is_unmerged) {
1488                        fprintf(options->file, "%s", line_prefix);
1489                        show_name(options->file, prefix, name, len);
1490                        fprintf(options->file, "  Unmerged\n");
1491                        continue;
1492                }
1493
1494                /*
1495                 * scale the add/delete
1496                 */
1497                add = added;
1498                del = deleted;
1499                adds += add;
1500                dels += del;
1501
1502                if (width <= max_change) {
1503                        int total = add + del;
1504
1505                        total = scale_linear(add + del, width, max_change);
1506                        if (total < 2 && add && del)
1507                                /* width >= 2 due to the sanity check */
1508                                total = 2;
1509                        if (add < del) {
1510                                add = scale_linear(add, width, max_change);
1511                                del = total - add;
1512                        } else {
1513                                del = scale_linear(del, width, max_change);
1514                                add = total - del;
1515                        }
1516                }
1517                fprintf(options->file, "%s", line_prefix);
1518                show_name(options->file, prefix, name, len);
1519                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1520                                added + deleted ? " " : "");
1521                show_graph(options->file, '+', add, add_c, reset);
1522                show_graph(options->file, '-', del, del_c, reset);
1523                fprintf(options->file, "\n");
1524        }
1525        for (i = count; i < data->nr; i++) {
1526                uintmax_t added = data->files[i]->added;
1527                uintmax_t deleted = data->files[i]->deleted;
1528                if (!data->files[i]->is_renamed &&
1529                         (added + deleted == 0)) {
1530                        total_files--;
1531                        continue;
1532                }
1533                adds += added;
1534                dels += deleted;
1535                if (!extra_shown)
1536                        fprintf(options->file, "%s ...\n", line_prefix);
1537                extra_shown = 1;
1538        }
1539        fprintf(options->file, "%s", line_prefix);
1540        print_stat_summary(options->file, total_files, adds, dels);
1541}
1542
1543static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1544{
1545        int i, adds = 0, dels = 0, total_files = data->nr;
1546
1547        if (data->nr == 0)
1548                return;
1549
1550        for (i = 0; i < data->nr; i++) {
1551                if (!data->files[i]->is_binary &&
1552                    !data->files[i]->is_unmerged) {
1553                        int added = data->files[i]->added;
1554                        int deleted= data->files[i]->deleted;
1555                        if (!data->files[i]->is_renamed &&
1556                            (added + deleted == 0)) {
1557                                total_files--;
1558                        } else {
1559                                adds += added;
1560                                dels += deleted;
1561                        }
1562                }
1563        }
1564        if (options->output_prefix) {
1565                struct strbuf *msg = NULL;
1566                msg = options->output_prefix(options,
1567                                options->output_prefix_data);
1568                fprintf(options->file, "%s", msg->buf);
1569        }
1570        print_stat_summary(options->file, total_files, adds, dels);
1571}
1572
1573static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1574{
1575        int i;
1576
1577        if (data->nr == 0)
1578                return;
1579
1580        for (i = 0; i < data->nr; i++) {
1581                struct diffstat_file *file = data->files[i];
1582
1583                if (options->output_prefix) {
1584                        struct strbuf *msg = NULL;
1585                        msg = options->output_prefix(options,
1586                                        options->output_prefix_data);
1587                        fprintf(options->file, "%s", msg->buf);
1588                }
1589
1590                if (file->is_binary)
1591                        fprintf(options->file, "-\t-\t");
1592                else
1593                        fprintf(options->file,
1594                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1595                                file->added, file->deleted);
1596                if (options->line_termination) {
1597                        fill_print_name(file);
1598                        if (!file->is_renamed)
1599                                write_name_quoted(file->name, options->file,
1600                                                  options->line_termination);
1601                        else {
1602                                fputs(file->print_name, options->file);
1603                                putc(options->line_termination, options->file);
1604                        }
1605                } else {
1606                        if (file->is_renamed) {
1607                                putc('\0', options->file);
1608                                write_name_quoted(file->from_name, options->file, '\0');
1609                        }
1610                        write_name_quoted(file->name, options->file, '\0');
1611                }
1612        }
1613}
1614
1615struct dirstat_file {
1616        const char *name;
1617        unsigned long changed;
1618};
1619
1620struct dirstat_dir {
1621        struct dirstat_file *files;
1622        int alloc, nr, permille, cumulative;
1623};
1624
1625static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1626                unsigned long changed, const char *base, int baselen)
1627{
1628        unsigned long this_dir = 0;
1629        unsigned int sources = 0;
1630        const char *line_prefix = "";
1631        struct strbuf *msg = NULL;
1632
1633        if (opt->output_prefix) {
1634                msg = opt->output_prefix(opt, opt->output_prefix_data);
1635                line_prefix = msg->buf;
1636        }
1637
1638        while (dir->nr) {
1639                struct dirstat_file *f = dir->files;
1640                int namelen = strlen(f->name);
1641                unsigned long this;
1642                char *slash;
1643
1644                if (namelen < baselen)
1645                        break;
1646                if (memcmp(f->name, base, baselen))
1647                        break;
1648                slash = strchr(f->name + baselen, '/');
1649                if (slash) {
1650                        int newbaselen = slash + 1 - f->name;
1651                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1652                        sources++;
1653                } else {
1654                        this = f->changed;
1655                        dir->files++;
1656                        dir->nr--;
1657                        sources += 2;
1658                }
1659                this_dir += this;
1660        }
1661
1662        /*
1663         * We don't report dirstat's for
1664         *  - the top level
1665         *  - or cases where everything came from a single directory
1666         *    under this directory (sources == 1).
1667         */
1668        if (baselen && sources != 1) {
1669                if (this_dir) {
1670                        int permille = this_dir * 1000 / changed;
1671                        if (permille >= dir->permille) {
1672                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1673                                        permille / 10, permille % 10, baselen, base);
1674                                if (!dir->cumulative)
1675                                        return 0;
1676                        }
1677                }
1678        }
1679        return this_dir;
1680}
1681
1682static int dirstat_compare(const void *_a, const void *_b)
1683{
1684        const struct dirstat_file *a = _a;
1685        const struct dirstat_file *b = _b;
1686        return strcmp(a->name, b->name);
1687}
1688
1689static void show_dirstat(struct diff_options *options)
1690{
1691        int i;
1692        unsigned long changed;
1693        struct dirstat_dir dir;
1694        struct diff_queue_struct *q = &diff_queued_diff;
1695
1696        dir.files = NULL;
1697        dir.alloc = 0;
1698        dir.nr = 0;
1699        dir.permille = options->dirstat_permille;
1700        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1701
1702        changed = 0;
1703        for (i = 0; i < q->nr; i++) {
1704                struct diff_filepair *p = q->queue[i];
1705                const char *name;
1706                unsigned long copied, added, damage;
1707                int content_changed;
1708
1709                name = p->two->path ? p->two->path : p->one->path;
1710
1711                if (p->one->sha1_valid && p->two->sha1_valid)
1712                        content_changed = hashcmp(p->one->sha1, p->two->sha1);
1713                else
1714                        content_changed = 1;
1715
1716                if (!content_changed) {
1717                        /*
1718                         * The SHA1 has not changed, so pre-/post-content is
1719                         * identical. We can therefore skip looking at the
1720                         * file contents altogether.
1721                         */
1722                        damage = 0;
1723                        goto found_damage;
1724                }
1725
1726                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1727                        /*
1728                         * In --dirstat-by-file mode, we don't really need to
1729                         * look at the actual file contents at all.
1730                         * The fact that the SHA1 changed is enough for us to
1731                         * add this file to the list of results
1732                         * (with each file contributing equal damage).
1733                         */
1734                        damage = 1;
1735                        goto found_damage;
1736                }
1737
1738                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1739                        diff_populate_filespec(p->one, 0);
1740                        diff_populate_filespec(p->two, 0);
1741                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1742                                               &copied, &added);
1743                        diff_free_filespec_data(p->one);
1744                        diff_free_filespec_data(p->two);
1745                } else if (DIFF_FILE_VALID(p->one)) {
1746                        diff_populate_filespec(p->one, 1);
1747                        copied = added = 0;
1748                        diff_free_filespec_data(p->one);
1749                } else if (DIFF_FILE_VALID(p->two)) {
1750                        diff_populate_filespec(p->two, 1);
1751                        copied = 0;
1752                        added = p->two->size;
1753                        diff_free_filespec_data(p->two);
1754                } else
1755                        continue;
1756
1757                /*
1758                 * Original minus copied is the removed material,
1759                 * added is the new material.  They are both damages
1760                 * made to the preimage.
1761                 * If the resulting damage is zero, we know that
1762                 * diffcore_count_changes() considers the two entries to
1763                 * be identical, but since content_changed is true, we
1764                 * know that there must have been _some_ kind of change,
1765                 * so we force all entries to have damage > 0.
1766                 */
1767                damage = (p->one->size - copied) + added;
1768                if (!damage)
1769                        damage = 1;
1770
1771found_damage:
1772                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1773                dir.files[dir.nr].name = name;
1774                dir.files[dir.nr].changed = damage;
1775                changed += damage;
1776                dir.nr++;
1777        }
1778
1779        /* This can happen even with many files, if everything was renames */
1780        if (!changed)
1781                return;
1782
1783        /* Show all directories with more than x% of the changes */
1784        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1785        gather_dirstat(options, &dir, changed, "", 0);
1786}
1787
1788static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
1789{
1790        int i;
1791        unsigned long changed;
1792        struct dirstat_dir dir;
1793
1794        if (data->nr == 0)
1795                return;
1796
1797        dir.files = NULL;
1798        dir.alloc = 0;
1799        dir.nr = 0;
1800        dir.permille = options->dirstat_permille;
1801        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1802
1803        changed = 0;
1804        for (i = 0; i < data->nr; i++) {
1805                struct diffstat_file *file = data->files[i];
1806                unsigned long damage = file->added + file->deleted;
1807                if (file->is_binary)
1808                        /*
1809                         * binary files counts bytes, not lines. Must find some
1810                         * way to normalize binary bytes vs. textual lines.
1811                         * The following heuristic assumes that there are 64
1812                         * bytes per "line".
1813                         * This is stupid and ugly, but very cheap...
1814                         */
1815                        damage = (damage + 63) / 64;
1816                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1817                dir.files[dir.nr].name = file->name;
1818                dir.files[dir.nr].changed = damage;
1819                changed += damage;
1820                dir.nr++;
1821        }
1822
1823        /* This can happen even with many files, if everything was renames */
1824        if (!changed)
1825                return;
1826
1827        /* Show all directories with more than x% of the changes */
1828        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1829        gather_dirstat(options, &dir, changed, "", 0);
1830}
1831
1832static void free_diffstat_info(struct diffstat_t *diffstat)
1833{
1834        int i;
1835        for (i = 0; i < diffstat->nr; i++) {
1836                struct diffstat_file *f = diffstat->files[i];
1837                if (f->name != f->print_name)
1838                        free(f->print_name);
1839                free(f->name);
1840                free(f->from_name);
1841                free(f);
1842        }
1843        free(diffstat->files);
1844}
1845
1846struct checkdiff_t {
1847        const char *filename;
1848        int lineno;
1849        int conflict_marker_size;
1850        struct diff_options *o;
1851        unsigned ws_rule;
1852        unsigned status;
1853};
1854
1855static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1856{
1857        char firstchar;
1858        int cnt;
1859
1860        if (len < marker_size + 1)
1861                return 0;
1862        firstchar = line[0];
1863        switch (firstchar) {
1864        case '=': case '>': case '<': case '|':
1865                break;
1866        default:
1867                return 0;
1868        }
1869        for (cnt = 1; cnt < marker_size; cnt++)
1870                if (line[cnt] != firstchar)
1871                        return 0;
1872        /* line[1] thru line[marker_size-1] are same as firstchar */
1873        if (len < marker_size + 1 || !isspace(line[marker_size]))
1874                return 0;
1875        return 1;
1876}
1877
1878static void checkdiff_consume(void *priv, char *line, unsigned long len)
1879{
1880        struct checkdiff_t *data = priv;
1881        int marker_size = data->conflict_marker_size;
1882        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
1883        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
1884        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
1885        char *err;
1886        char *line_prefix = "";
1887        struct strbuf *msgbuf;
1888
1889        assert(data->o);
1890        if (data->o->output_prefix) {
1891                msgbuf = data->o->output_prefix(data->o,
1892                        data->o->output_prefix_data);
1893                line_prefix = msgbuf->buf;
1894        }
1895
1896        if (line[0] == '+') {
1897                unsigned bad;
1898                data->lineno++;
1899                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1900                        data->status |= 1;
1901                        fprintf(data->o->file,
1902                                "%s%s:%d: leftover conflict marker\n",
1903                                line_prefix, data->filename, data->lineno);
1904                }
1905                bad = ws_check(line + 1, len - 1, data->ws_rule);
1906                if (!bad)
1907                        return;
1908                data->status |= bad;
1909                err = whitespace_error_string(bad);
1910                fprintf(data->o->file, "%s%s:%d: %s.\n",
1911                        line_prefix, data->filename, data->lineno, err);
1912                free(err);
1913                emit_line(data->o, set, reset, line, 1);
1914                ws_check_emit(line + 1, len - 1, data->ws_rule,
1915                              data->o->file, set, reset, ws);
1916        } else if (line[0] == ' ') {
1917                data->lineno++;
1918        } else if (line[0] == '@') {
1919                char *plus = strchr(line, '+');
1920                if (plus)
1921                        data->lineno = strtol(plus, NULL, 10) - 1;
1922                else
1923                        die("invalid diff");
1924        }
1925}
1926
1927static unsigned char *deflate_it(char *data,
1928                                 unsigned long size,
1929                                 unsigned long *result_size)
1930{
1931        int bound;
1932        unsigned char *deflated;
1933        git_zstream stream;
1934
1935        memset(&stream, 0, sizeof(stream));
1936        git_deflate_init(&stream, zlib_compression_level);
1937        bound = git_deflate_bound(&stream, size);
1938        deflated = xmalloc(bound);
1939        stream.next_out = deflated;
1940        stream.avail_out = bound;
1941
1942        stream.next_in = (unsigned char *)data;
1943        stream.avail_in = size;
1944        while (git_deflate(&stream, Z_FINISH) == Z_OK)
1945                ; /* nothing */
1946        git_deflate_end(&stream);
1947        *result_size = stream.total_out;
1948        return deflated;
1949}
1950
1951static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1952{
1953        void *cp;
1954        void *delta;
1955        void *deflated;
1956        void *data;
1957        unsigned long orig_size;
1958        unsigned long delta_size;
1959        unsigned long deflate_size;
1960        unsigned long data_size;
1961
1962        /* We could do deflated delta, or we could do just deflated two,
1963         * whichever is smaller.
1964         */
1965        delta = NULL;
1966        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1967        if (one->size && two->size) {
1968                delta = diff_delta(one->ptr, one->size,
1969                                   two->ptr, two->size,
1970                                   &delta_size, deflate_size);
1971                if (delta) {
1972                        void *to_free = delta;
1973                        orig_size = delta_size;
1974                        delta = deflate_it(delta, delta_size, &delta_size);
1975                        free(to_free);
1976                }
1977        }
1978
1979        if (delta && delta_size < deflate_size) {
1980                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1981                free(deflated);
1982                data = delta;
1983                data_size = delta_size;
1984        }
1985        else {
1986                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1987                free(delta);
1988                data = deflated;
1989                data_size = deflate_size;
1990        }
1991
1992        /* emit data encoded in base85 */
1993        cp = data;
1994        while (data_size) {
1995                int bytes = (52 < data_size) ? 52 : data_size;
1996                char line[70];
1997                data_size -= bytes;
1998                if (bytes <= 26)
1999                        line[0] = bytes + 'A' - 1;
2000                else
2001                        line[0] = bytes - 26 + 'a' - 1;
2002                encode_85(line + 1, cp, bytes);
2003                cp = (char *) cp + bytes;
2004                fprintf(file, "%s", prefix);
2005                fputs(line, file);
2006                fputc('\n', file);
2007        }
2008        fprintf(file, "%s\n", prefix);
2009        free(data);
2010}
2011
2012static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
2013{
2014        fprintf(file, "%sGIT binary patch\n", prefix);
2015        emit_binary_diff_body(file, one, two, prefix);
2016        emit_binary_diff_body(file, two, one, prefix);
2017}
2018
2019static void diff_filespec_load_driver(struct diff_filespec *one)
2020{
2021        /* Use already-loaded driver */
2022        if (one->driver)
2023                return;
2024
2025        if (S_ISREG(one->mode))
2026                one->driver = userdiff_find_by_path(one->path);
2027
2028        /* Fallback to default settings */
2029        if (!one->driver)
2030                one->driver = userdiff_find_by_name("default");
2031}
2032
2033int diff_filespec_is_binary(struct diff_filespec *one)
2034{
2035        if (one->is_binary == -1) {
2036                diff_filespec_load_driver(one);
2037                if (one->driver->binary != -1)
2038                        one->is_binary = one->driver->binary;
2039                else {
2040                        if (!one->data && DIFF_FILE_VALID(one))
2041                                diff_populate_filespec(one, 0);
2042                        if (one->data)
2043                                one->is_binary = buffer_is_binary(one->data,
2044                                                one->size);
2045                        if (one->is_binary == -1)
2046                                one->is_binary = 0;
2047                }
2048        }
2049        return one->is_binary;
2050}
2051
2052static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2053{
2054        diff_filespec_load_driver(one);
2055        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2056}
2057
2058static const char *userdiff_word_regex(struct diff_filespec *one)
2059{
2060        diff_filespec_load_driver(one);
2061        return one->driver->word_regex;
2062}
2063
2064void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2065{
2066        if (!options->a_prefix)
2067                options->a_prefix = a;
2068        if (!options->b_prefix)
2069                options->b_prefix = b;
2070}
2071
2072struct userdiff_driver *get_textconv(struct diff_filespec *one)
2073{
2074        if (!DIFF_FILE_VALID(one))
2075                return NULL;
2076
2077        diff_filespec_load_driver(one);
2078        return userdiff_get_textconv(one->driver);
2079}
2080
2081static void builtin_diff(const char *name_a,
2082                         const char *name_b,
2083                         struct diff_filespec *one,
2084                         struct diff_filespec *two,
2085                         const char *xfrm_msg,
2086                         int must_show_header,
2087                         struct diff_options *o,
2088                         int complete_rewrite)
2089{
2090        mmfile_t mf1, mf2;
2091        const char *lbl[2];
2092        char *a_one, *b_two;
2093        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
2094        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2095        const char *a_prefix, *b_prefix;
2096        struct userdiff_driver *textconv_one = NULL;
2097        struct userdiff_driver *textconv_two = NULL;
2098        struct strbuf header = STRBUF_INIT;
2099        struct strbuf *msgbuf;
2100        char *line_prefix = "";
2101
2102        if (o->output_prefix) {
2103                msgbuf = o->output_prefix(o, o->output_prefix_data);
2104                line_prefix = msgbuf->buf;
2105        }
2106
2107        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
2108                        (!one->mode || S_ISGITLINK(one->mode)) &&
2109                        (!two->mode || S_ISGITLINK(two->mode))) {
2110                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2111                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2112                show_submodule_summary(o->file, one ? one->path : two->path,
2113                                one->sha1, two->sha1, two->dirty_submodule,
2114                                del, add, reset);
2115                return;
2116        }
2117
2118        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2119                textconv_one = get_textconv(one);
2120                textconv_two = get_textconv(two);
2121        }
2122
2123        diff_set_mnemonic_prefix(o, "a/", "b/");
2124        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2125                a_prefix = o->b_prefix;
2126                b_prefix = o->a_prefix;
2127        } else {
2128                a_prefix = o->a_prefix;
2129                b_prefix = o->b_prefix;
2130        }
2131
2132        /* Never use a non-valid filename anywhere if at all possible */
2133        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2134        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2135
2136        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2137        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2138        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2139        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2140        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
2141        if (lbl[0][0] == '/') {
2142                /* /dev/null */
2143                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
2144                if (xfrm_msg)
2145                        strbuf_addstr(&header, xfrm_msg);
2146                must_show_header = 1;
2147        }
2148        else if (lbl[1][0] == '/') {
2149                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
2150                if (xfrm_msg)
2151                        strbuf_addstr(&header, xfrm_msg);
2152                must_show_header = 1;
2153        }
2154        else {
2155                if (one->mode != two->mode) {
2156                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
2157                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
2158                        must_show_header = 1;
2159                }
2160                if (xfrm_msg)
2161                        strbuf_addstr(&header, xfrm_msg);
2162
2163                /*
2164                 * we do not run diff between different kind
2165                 * of objects.
2166                 */
2167                if ((one->mode ^ two->mode) & S_IFMT)
2168                        goto free_ab_and_return;
2169                if (complete_rewrite &&
2170                    (textconv_one || !diff_filespec_is_binary(one)) &&
2171                    (textconv_two || !diff_filespec_is_binary(two))) {
2172                        fprintf(o->file, "%s", header.buf);
2173                        strbuf_reset(&header);
2174                        emit_rewrite_diff(name_a, name_b, one, two,
2175                                                textconv_one, textconv_two, o);
2176                        o->found_changes = 1;
2177                        goto free_ab_and_return;
2178                }
2179        }
2180
2181        if (o->irreversible_delete && lbl[1][0] == '/') {
2182                fprintf(o->file, "%s", header.buf);
2183                strbuf_reset(&header);
2184                goto free_ab_and_return;
2185        } else if (!DIFF_OPT_TST(o, TEXT) &&
2186            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2187              (!textconv_two && diff_filespec_is_binary(two)) )) {
2188                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2189                        die("unable to read files to diff");
2190                /* Quite common confusing case */
2191                if (mf1.size == mf2.size &&
2192                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2193                        if (must_show_header)
2194                                fprintf(o->file, "%s", header.buf);
2195                        goto free_ab_and_return;
2196                }
2197                fprintf(o->file, "%s", header.buf);
2198                strbuf_reset(&header);
2199                if (DIFF_OPT_TST(o, BINARY))
2200                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2201                else
2202                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2203                                line_prefix, lbl[0], lbl[1]);
2204                o->found_changes = 1;
2205        } else {
2206                /* Crazy xdl interfaces.. */
2207                const char *diffopts = getenv("GIT_DIFF_OPTS");
2208                xpparam_t xpp;
2209                xdemitconf_t xecfg;
2210                struct emit_callback ecbdata;
2211                const struct userdiff_funcname *pe;
2212
2213                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
2214                        fprintf(o->file, "%s", header.buf);
2215                        strbuf_reset(&header);
2216                }
2217
2218                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2219                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2220
2221                pe = diff_funcname_pattern(one);
2222                if (!pe)
2223                        pe = diff_funcname_pattern(two);
2224
2225                memset(&xpp, 0, sizeof(xpp));
2226                memset(&xecfg, 0, sizeof(xecfg));
2227                memset(&ecbdata, 0, sizeof(ecbdata));
2228                ecbdata.label_path = lbl;
2229                ecbdata.color_diff = want_color(o->use_color);
2230                ecbdata.found_changesp = &o->found_changes;
2231                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
2232                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2233                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2234                ecbdata.opt = o;
2235                ecbdata.header = header.len ? &header : NULL;
2236                xpp.flags = o->xdl_opts;
2237                xecfg.ctxlen = o->context;
2238                xecfg.interhunkctxlen = o->interhunkcontext;
2239                xecfg.flags = XDL_EMIT_FUNCNAMES;
2240                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2241                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2242                if (pe)
2243                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2244                if (!diffopts)
2245                        ;
2246                else if (!prefixcmp(diffopts, "--unified="))
2247                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2248                else if (!prefixcmp(diffopts, "-u"))
2249                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2250                if (o->word_diff) {
2251                        int i;
2252
2253                        ecbdata.diff_words =
2254                                xcalloc(1, sizeof(struct diff_words_data));
2255                        ecbdata.diff_words->type = o->word_diff;
2256                        ecbdata.diff_words->opt = o;
2257                        if (!o->word_regex)
2258                                o->word_regex = userdiff_word_regex(one);
2259                        if (!o->word_regex)
2260                                o->word_regex = userdiff_word_regex(two);
2261                        if (!o->word_regex)
2262                                o->word_regex = diff_word_regex_cfg;
2263                        if (o->word_regex) {
2264                                ecbdata.diff_words->word_regex = (regex_t *)
2265                                        xmalloc(sizeof(regex_t));
2266                                if (regcomp(ecbdata.diff_words->word_regex,
2267                                                o->word_regex,
2268                                                REG_EXTENDED | REG_NEWLINE))
2269                                        die ("Invalid regular expression: %s",
2270                                                        o->word_regex);
2271                        }
2272                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2273                                if (o->word_diff == diff_words_styles[i].type) {
2274                                        ecbdata.diff_words->style =
2275                                                &diff_words_styles[i];
2276                                        break;
2277                                }
2278                        }
2279                        if (want_color(o->use_color)) {
2280                                struct diff_words_style *st = ecbdata.diff_words->style;
2281                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2282                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2283                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2284                        }
2285                }
2286                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2287                              &xpp, &xecfg);
2288                if (o->word_diff)
2289                        free_diff_words_data(&ecbdata);
2290                if (textconv_one)
2291                        free(mf1.ptr);
2292                if (textconv_two)
2293                        free(mf2.ptr);
2294                xdiff_clear_find_func(&xecfg);
2295        }
2296
2297 free_ab_and_return:
2298        strbuf_release(&header);
2299        diff_free_filespec_data(one);
2300        diff_free_filespec_data(two);
2301        free(a_one);
2302        free(b_two);
2303        return;
2304}
2305
2306static void builtin_diffstat(const char *name_a, const char *name_b,
2307                             struct diff_filespec *one,
2308                             struct diff_filespec *two,
2309                             struct diffstat_t *diffstat,
2310                             struct diff_options *o,
2311                             int complete_rewrite)
2312{
2313        mmfile_t mf1, mf2;
2314        struct diffstat_file *data;
2315
2316        data = diffstat_add(diffstat, name_a, name_b);
2317
2318        if (!one || !two) {
2319                data->is_unmerged = 1;
2320                return;
2321        }
2322
2323        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2324                data->is_binary = 1;
2325                data->added = diff_filespec_size(two);
2326                data->deleted = diff_filespec_size(one);
2327        }
2328
2329        else if (complete_rewrite) {
2330                diff_populate_filespec(one, 0);
2331                diff_populate_filespec(two, 0);
2332                data->deleted = count_lines(one->data, one->size);
2333                data->added = count_lines(two->data, two->size);
2334        }
2335
2336        else {
2337                /* Crazy xdl interfaces.. */
2338                xpparam_t xpp;
2339                xdemitconf_t xecfg;
2340
2341                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2342                        die("unable to read files to diff");
2343
2344                memset(&xpp, 0, sizeof(xpp));
2345                memset(&xecfg, 0, sizeof(xecfg));
2346                xpp.flags = o->xdl_opts;
2347                xecfg.ctxlen = o->context;
2348                xecfg.interhunkctxlen = o->interhunkcontext;
2349                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2350                              &xpp, &xecfg);
2351        }
2352
2353        diff_free_filespec_data(one);
2354        diff_free_filespec_data(two);
2355}
2356
2357static void builtin_checkdiff(const char *name_a, const char *name_b,
2358                              const char *attr_path,
2359                              struct diff_filespec *one,
2360                              struct diff_filespec *two,
2361                              struct diff_options *o)
2362{
2363        mmfile_t mf1, mf2;
2364        struct checkdiff_t data;
2365
2366        if (!two)
2367                return;
2368
2369        memset(&data, 0, sizeof(data));
2370        data.filename = name_b ? name_b : name_a;
2371        data.lineno = 0;
2372        data.o = o;
2373        data.ws_rule = whitespace_rule(attr_path);
2374        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2375
2376        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2377                die("unable to read files to diff");
2378
2379        /*
2380         * All the other codepaths check both sides, but not checking
2381         * the "old" side here is deliberate.  We are checking the newly
2382         * introduced changes, and as long as the "new" side is text, we
2383         * can and should check what it introduces.
2384         */
2385        if (diff_filespec_is_binary(two))
2386                goto free_and_return;
2387        else {
2388                /* Crazy xdl interfaces.. */
2389                xpparam_t xpp;
2390                xdemitconf_t xecfg;
2391
2392                memset(&xpp, 0, sizeof(xpp));
2393                memset(&xecfg, 0, sizeof(xecfg));
2394                xecfg.ctxlen = 1; /* at least one context line */
2395                xpp.flags = 0;
2396                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2397                              &xpp, &xecfg);
2398
2399                if (data.ws_rule & WS_BLANK_AT_EOF) {
2400                        struct emit_callback ecbdata;
2401                        int blank_at_eof;
2402
2403                        ecbdata.ws_rule = data.ws_rule;
2404                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2405                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2406
2407                        if (blank_at_eof) {
2408                                static char *err;
2409                                if (!err)
2410                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2411                                fprintf(o->file, "%s:%d: %s.\n",
2412                                        data.filename, blank_at_eof, err);
2413                                data.status = 1; /* report errors */
2414                        }
2415                }
2416        }
2417 free_and_return:
2418        diff_free_filespec_data(one);
2419        diff_free_filespec_data(two);
2420        if (data.status)
2421                DIFF_OPT_SET(o, CHECK_FAILED);
2422}
2423
2424struct diff_filespec *alloc_filespec(const char *path)
2425{
2426        int namelen = strlen(path);
2427        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2428
2429        memset(spec, 0, sizeof(*spec));
2430        spec->path = (char *)(spec + 1);
2431        memcpy(spec->path, path, namelen+1);
2432        spec->count = 1;
2433        spec->is_binary = -1;
2434        return spec;
2435}
2436
2437void free_filespec(struct diff_filespec *spec)
2438{
2439        if (!--spec->count) {
2440                diff_free_filespec_data(spec);
2441                free(spec);
2442        }
2443}
2444
2445void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2446                   unsigned short mode)
2447{
2448        if (mode) {
2449                spec->mode = canon_mode(mode);
2450                hashcpy(spec->sha1, sha1);
2451                spec->sha1_valid = !is_null_sha1(sha1);
2452        }
2453}
2454
2455/*
2456 * Given a name and sha1 pair, if the index tells us the file in
2457 * the work tree has that object contents, return true, so that
2458 * prepare_temp_file() does not have to inflate and extract.
2459 */
2460static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2461{
2462        struct cache_entry *ce;
2463        struct stat st;
2464        int pos, len;
2465
2466        /*
2467         * We do not read the cache ourselves here, because the
2468         * benchmark with my previous version that always reads cache
2469         * shows that it makes things worse for diff-tree comparing
2470         * two linux-2.6 kernel trees in an already checked out work
2471         * tree.  This is because most diff-tree comparisons deal with
2472         * only a small number of files, while reading the cache is
2473         * expensive for a large project, and its cost outweighs the
2474         * savings we get by not inflating the object to a temporary
2475         * file.  Practically, this code only helps when we are used
2476         * by diff-cache --cached, which does read the cache before
2477         * calling us.
2478         */
2479        if (!active_cache)
2480                return 0;
2481
2482        /* We want to avoid the working directory if our caller
2483         * doesn't need the data in a normal file, this system
2484         * is rather slow with its stat/open/mmap/close syscalls,
2485         * and the object is contained in a pack file.  The pack
2486         * is probably already open and will be faster to obtain
2487         * the data through than the working directory.  Loose
2488         * objects however would tend to be slower as they need
2489         * to be individually opened and inflated.
2490         */
2491        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2492                return 0;
2493
2494        len = strlen(name);
2495        pos = cache_name_pos(name, len);
2496        if (pos < 0)
2497                return 0;
2498        ce = active_cache[pos];
2499
2500        /*
2501         * This is not the sha1 we are looking for, or
2502         * unreusable because it is not a regular file.
2503         */
2504        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2505                return 0;
2506
2507        /*
2508         * If ce is marked as "assume unchanged", there is no
2509         * guarantee that work tree matches what we are looking for.
2510         */
2511        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2512                return 0;
2513
2514        /*
2515         * If ce matches the file in the work tree, we can reuse it.
2516         */
2517        if (ce_uptodate(ce) ||
2518            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2519                return 1;
2520
2521        return 0;
2522}
2523
2524static int populate_from_stdin(struct diff_filespec *s)
2525{
2526        struct strbuf buf = STRBUF_INIT;
2527        size_t size = 0;
2528
2529        if (strbuf_read(&buf, 0, 0) < 0)
2530                return error("error while reading from stdin %s",
2531                                     strerror(errno));
2532
2533        s->should_munmap = 0;
2534        s->data = strbuf_detach(&buf, &size);
2535        s->size = size;
2536        s->should_free = 1;
2537        return 0;
2538}
2539
2540static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2541{
2542        int len;
2543        char *data = xmalloc(100), *dirty = "";
2544
2545        /* Are we looking at the work tree? */
2546        if (s->dirty_submodule)
2547                dirty = "-dirty";
2548
2549        len = snprintf(data, 100,
2550                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2551        s->data = data;
2552        s->size = len;
2553        s->should_free = 1;
2554        if (size_only) {
2555                s->data = NULL;
2556                free(data);
2557        }
2558        return 0;
2559}
2560
2561/*
2562 * While doing rename detection and pickaxe operation, we may need to
2563 * grab the data for the blob (or file) for our own in-core comparison.
2564 * diff_filespec has data and size fields for this purpose.
2565 */
2566int diff_populate_filespec(struct diff_filespec *s, int size_only)
2567{
2568        int err = 0;
2569        if (!DIFF_FILE_VALID(s))
2570                die("internal error: asking to populate invalid file.");
2571        if (S_ISDIR(s->mode))
2572                return -1;
2573
2574        if (s->data)
2575                return 0;
2576
2577        if (size_only && 0 < s->size)
2578                return 0;
2579
2580        if (S_ISGITLINK(s->mode))
2581                return diff_populate_gitlink(s, size_only);
2582
2583        if (!s->sha1_valid ||
2584            reuse_worktree_file(s->path, s->sha1, 0)) {
2585                struct strbuf buf = STRBUF_INIT;
2586                struct stat st;
2587                int fd;
2588
2589                if (!strcmp(s->path, "-"))
2590                        return populate_from_stdin(s);
2591
2592                if (lstat(s->path, &st) < 0) {
2593                        if (errno == ENOENT) {
2594                        err_empty:
2595                                err = -1;
2596                        empty:
2597                                s->data = (char *)"";
2598                                s->size = 0;
2599                                return err;
2600                        }
2601                }
2602                s->size = xsize_t(st.st_size);
2603                if (!s->size)
2604                        goto empty;
2605                if (S_ISLNK(st.st_mode)) {
2606                        struct strbuf sb = STRBUF_INIT;
2607
2608                        if (strbuf_readlink(&sb, s->path, s->size))
2609                                goto err_empty;
2610                        s->size = sb.len;
2611                        s->data = strbuf_detach(&sb, NULL);
2612                        s->should_free = 1;
2613                        return 0;
2614                }
2615                if (size_only)
2616                        return 0;
2617                fd = open(s->path, O_RDONLY);
2618                if (fd < 0)
2619                        goto err_empty;
2620                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2621                close(fd);
2622                s->should_munmap = 1;
2623
2624                /*
2625                 * Convert from working tree format to canonical git format
2626                 */
2627                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2628                        size_t size = 0;
2629                        munmap(s->data, s->size);
2630                        s->should_munmap = 0;
2631                        s->data = strbuf_detach(&buf, &size);
2632                        s->size = size;
2633                        s->should_free = 1;
2634                }
2635        }
2636        else {
2637                enum object_type type;
2638                if (size_only) {
2639                        type = sha1_object_info(s->sha1, &s->size);
2640                        if (type < 0)
2641                                die("unable to read %s", sha1_to_hex(s->sha1));
2642                } else {
2643                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2644                        if (!s->data)
2645                                die("unable to read %s", sha1_to_hex(s->sha1));
2646                        s->should_free = 1;
2647                }
2648        }
2649        return 0;
2650}
2651
2652void diff_free_filespec_blob(struct diff_filespec *s)
2653{
2654        if (s->should_free)
2655                free(s->data);
2656        else if (s->should_munmap)
2657                munmap(s->data, s->size);
2658
2659        if (s->should_free || s->should_munmap) {
2660                s->should_free = s->should_munmap = 0;
2661                s->data = NULL;
2662        }
2663}
2664
2665void diff_free_filespec_data(struct diff_filespec *s)
2666{
2667        diff_free_filespec_blob(s);
2668        free(s->cnt_data);
2669        s->cnt_data = NULL;
2670}
2671
2672static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2673                           void *blob,
2674                           unsigned long size,
2675                           const unsigned char *sha1,
2676                           int mode)
2677{
2678        int fd;
2679        struct strbuf buf = STRBUF_INIT;
2680        struct strbuf template = STRBUF_INIT;
2681        char *path_dup = xstrdup(path);
2682        const char *base = basename(path_dup);
2683
2684        /* Generate "XXXXXX_basename.ext" */
2685        strbuf_addstr(&template, "XXXXXX_");
2686        strbuf_addstr(&template, base);
2687
2688        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2689                        strlen(base) + 1);
2690        if (fd < 0)
2691                die_errno("unable to create temp-file");
2692        if (convert_to_working_tree(path,
2693                        (const char *)blob, (size_t)size, &buf)) {
2694                blob = buf.buf;
2695                size = buf.len;
2696        }
2697        if (write_in_full(fd, blob, size) != size)
2698                die_errno("unable to write temp-file");
2699        close(fd);
2700        temp->name = temp->tmp_path;
2701        strcpy(temp->hex, sha1_to_hex(sha1));
2702        temp->hex[40] = 0;
2703        sprintf(temp->mode, "%06o", mode);
2704        strbuf_release(&buf);
2705        strbuf_release(&template);
2706        free(path_dup);
2707}
2708
2709static struct diff_tempfile *prepare_temp_file(const char *name,
2710                struct diff_filespec *one)
2711{
2712        struct diff_tempfile *temp = claim_diff_tempfile();
2713
2714        if (!DIFF_FILE_VALID(one)) {
2715        not_a_valid_file:
2716                /* A '-' entry produces this for file-2, and
2717                 * a '+' entry produces this for file-1.
2718                 */
2719                temp->name = "/dev/null";
2720                strcpy(temp->hex, ".");
2721                strcpy(temp->mode, ".");
2722                return temp;
2723        }
2724
2725        if (!remove_tempfile_installed) {
2726                atexit(remove_tempfile);
2727                sigchain_push_common(remove_tempfile_on_signal);
2728                remove_tempfile_installed = 1;
2729        }
2730
2731        if (!one->sha1_valid ||
2732            reuse_worktree_file(name, one->sha1, 1)) {
2733                struct stat st;
2734                if (lstat(name, &st) < 0) {
2735                        if (errno == ENOENT)
2736                                goto not_a_valid_file;
2737                        die_errno("stat(%s)", name);
2738                }
2739                if (S_ISLNK(st.st_mode)) {
2740                        struct strbuf sb = STRBUF_INIT;
2741                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2742                                die_errno("readlink(%s)", name);
2743                        prep_temp_blob(name, temp, sb.buf, sb.len,
2744                                       (one->sha1_valid ?
2745                                        one->sha1 : null_sha1),
2746                                       (one->sha1_valid ?
2747                                        one->mode : S_IFLNK));
2748                        strbuf_release(&sb);
2749                }
2750                else {
2751                        /* we can borrow from the file in the work tree */
2752                        temp->name = name;
2753                        if (!one->sha1_valid)
2754                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2755                        else
2756                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2757                        /* Even though we may sometimes borrow the
2758                         * contents from the work tree, we always want
2759                         * one->mode.  mode is trustworthy even when
2760                         * !(one->sha1_valid), as long as
2761                         * DIFF_FILE_VALID(one).
2762                         */
2763                        sprintf(temp->mode, "%06o", one->mode);
2764                }
2765                return temp;
2766        }
2767        else {
2768                if (diff_populate_filespec(one, 0))
2769                        die("cannot read data blob for %s", one->path);
2770                prep_temp_blob(name, temp, one->data, one->size,
2771                               one->sha1, one->mode);
2772        }
2773        return temp;
2774}
2775
2776/* An external diff command takes:
2777 *
2778 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2779 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2780 *
2781 */
2782static void run_external_diff(const char *pgm,
2783                              const char *name,
2784                              const char *other,
2785                              struct diff_filespec *one,
2786                              struct diff_filespec *two,
2787                              const char *xfrm_msg,
2788                              int complete_rewrite)
2789{
2790        const char *spawn_arg[10];
2791        int retval;
2792        const char **arg = &spawn_arg[0];
2793
2794        if (one && two) {
2795                struct diff_tempfile *temp_one, *temp_two;
2796                const char *othername = (other ? other : name);
2797                temp_one = prepare_temp_file(name, one);
2798                temp_two = prepare_temp_file(othername, two);
2799                *arg++ = pgm;
2800                *arg++ = name;
2801                *arg++ = temp_one->name;
2802                *arg++ = temp_one->hex;
2803                *arg++ = temp_one->mode;
2804                *arg++ = temp_two->name;
2805                *arg++ = temp_two->hex;
2806                *arg++ = temp_two->mode;
2807                if (other) {
2808                        *arg++ = other;
2809                        *arg++ = xfrm_msg;
2810                }
2811        } else {
2812                *arg++ = pgm;
2813                *arg++ = name;
2814        }
2815        *arg = NULL;
2816        fflush(NULL);
2817        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2818        remove_tempfile();
2819        if (retval) {
2820                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2821                exit(1);
2822        }
2823}
2824
2825static int similarity_index(struct diff_filepair *p)
2826{
2827        return p->score * 100 / MAX_SCORE;
2828}
2829
2830static void fill_metainfo(struct strbuf *msg,
2831                          const char *name,
2832                          const char *other,
2833                          struct diff_filespec *one,
2834                          struct diff_filespec *two,
2835                          struct diff_options *o,
2836                          struct diff_filepair *p,
2837                          int *must_show_header,
2838                          int use_color)
2839{
2840        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2841        const char *reset = diff_get_color(use_color, DIFF_RESET);
2842        struct strbuf *msgbuf;
2843        char *line_prefix = "";
2844
2845        *must_show_header = 1;
2846        if (o->output_prefix) {
2847                msgbuf = o->output_prefix(o, o->output_prefix_data);
2848                line_prefix = msgbuf->buf;
2849        }
2850        strbuf_init(msg, PATH_MAX * 2 + 300);
2851        switch (p->status) {
2852        case DIFF_STATUS_COPIED:
2853                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2854                            line_prefix, set, similarity_index(p));
2855                strbuf_addf(msg, "%s\n%s%scopy from ",
2856                            reset,  line_prefix, set);
2857                quote_c_style(name, msg, NULL, 0);
2858                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2859                quote_c_style(other, msg, NULL, 0);
2860                strbuf_addf(msg, "%s\n", reset);
2861                break;
2862        case DIFF_STATUS_RENAMED:
2863                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2864                            line_prefix, set, similarity_index(p));
2865                strbuf_addf(msg, "%s\n%s%srename from ",
2866                            reset, line_prefix, set);
2867                quote_c_style(name, msg, NULL, 0);
2868                strbuf_addf(msg, "%s\n%s%srename to ",
2869                            reset, line_prefix, set);
2870                quote_c_style(other, msg, NULL, 0);
2871                strbuf_addf(msg, "%s\n", reset);
2872                break;
2873        case DIFF_STATUS_MODIFIED:
2874                if (p->score) {
2875                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2876                                    line_prefix,
2877                                    set, similarity_index(p), reset);
2878                        break;
2879                }
2880                /* fallthru */
2881        default:
2882                *must_show_header = 0;
2883        }
2884        if (one && two && hashcmp(one->sha1, two->sha1)) {
2885                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2886
2887                if (DIFF_OPT_TST(o, BINARY)) {
2888                        mmfile_t mf;
2889                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2890                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2891                                abbrev = 40;
2892                }
2893                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2894                            find_unique_abbrev(one->sha1, abbrev));
2895                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2896                if (one->mode == two->mode)
2897                        strbuf_addf(msg, " %06o", one->mode);
2898                strbuf_addf(msg, "%s\n", reset);
2899        }
2900}
2901
2902static void run_diff_cmd(const char *pgm,
2903                         const char *name,
2904                         const char *other,
2905                         const char *attr_path,
2906                         struct diff_filespec *one,
2907                         struct diff_filespec *two,
2908                         struct strbuf *msg,
2909                         struct diff_options *o,
2910                         struct diff_filepair *p)
2911{
2912        const char *xfrm_msg = NULL;
2913        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2914        int must_show_header = 0;
2915
2916        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2917                pgm = NULL;
2918        else {
2919                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2920                if (drv && drv->external)
2921                        pgm = drv->external;
2922        }
2923
2924        if (msg) {
2925                /*
2926                 * don't use colors when the header is intended for an
2927                 * external diff driver
2928                 */
2929                fill_metainfo(msg, name, other, one, two, o, p,
2930                              &must_show_header,
2931                              want_color(o->use_color) && !pgm);
2932                xfrm_msg = msg->len ? msg->buf : NULL;
2933        }
2934
2935        if (pgm) {
2936                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2937                                  complete_rewrite);
2938                return;
2939        }
2940        if (one && two)
2941                builtin_diff(name, other ? other : name,
2942                             one, two, xfrm_msg, must_show_header,
2943                             o, complete_rewrite);
2944        else
2945                fprintf(o->file, "* Unmerged path %s\n", name);
2946}
2947
2948static void diff_fill_sha1_info(struct diff_filespec *one)
2949{
2950        if (DIFF_FILE_VALID(one)) {
2951                if (!one->sha1_valid) {
2952                        struct stat st;
2953                        if (!strcmp(one->path, "-")) {
2954                                hashcpy(one->sha1, null_sha1);
2955                                return;
2956                        }
2957                        if (lstat(one->path, &st) < 0)
2958                                die_errno("stat '%s'", one->path);
2959                        if (index_path(one->sha1, one->path, &st, 0))
2960                                die("cannot hash %s", one->path);
2961                }
2962        }
2963        else
2964                hashclr(one->sha1);
2965}
2966
2967static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2968{
2969        /* Strip the prefix but do not molest /dev/null and absolute paths */
2970        if (*namep && **namep != '/') {
2971                *namep += prefix_length;
2972                if (**namep == '/')
2973                        ++*namep;
2974        }
2975        if (*otherp && **otherp != '/') {
2976                *otherp += prefix_length;
2977                if (**otherp == '/')
2978                        ++*otherp;
2979        }
2980}
2981
2982static void run_diff(struct diff_filepair *p, struct diff_options *o)
2983{
2984        const char *pgm = external_diff();
2985        struct strbuf msg;
2986        struct diff_filespec *one = p->one;
2987        struct diff_filespec *two = p->two;
2988        const char *name;
2989        const char *other;
2990        const char *attr_path;
2991
2992        name  = p->one->path;
2993        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2994        attr_path = name;
2995        if (o->prefix_length)
2996                strip_prefix(o->prefix_length, &name, &other);
2997
2998        if (DIFF_PAIR_UNMERGED(p)) {
2999                run_diff_cmd(pgm, name, NULL, attr_path,
3000                             NULL, NULL, NULL, o, p);
3001                return;
3002        }
3003
3004        diff_fill_sha1_info(one);
3005        diff_fill_sha1_info(two);
3006
3007        if (!pgm &&
3008            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3009            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3010                /*
3011                 * a filepair that changes between file and symlink
3012                 * needs to be split into deletion and creation.
3013                 */
3014                struct diff_filespec *null = alloc_filespec(two->path);
3015                run_diff_cmd(NULL, name, other, attr_path,
3016                             one, null, &msg, o, p);
3017                free(null);
3018                strbuf_release(&msg);
3019
3020                null = alloc_filespec(one->path);
3021                run_diff_cmd(NULL, name, other, attr_path,
3022                             null, two, &msg, o, p);
3023                free(null);
3024        }
3025        else
3026                run_diff_cmd(pgm, name, other, attr_path,
3027                             one, two, &msg, o, p);
3028
3029        strbuf_release(&msg);
3030}
3031
3032static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3033                         struct diffstat_t *diffstat)
3034{
3035        const char *name;
3036        const char *other;
3037        int complete_rewrite = 0;
3038
3039        if (DIFF_PAIR_UNMERGED(p)) {
3040                /* unmerged */
3041                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
3042                return;
3043        }
3044
3045        name = p->one->path;
3046        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3047
3048        if (o->prefix_length)
3049                strip_prefix(o->prefix_length, &name, &other);
3050
3051        diff_fill_sha1_info(p->one);
3052        diff_fill_sha1_info(p->two);
3053
3054        if (p->status == DIFF_STATUS_MODIFIED && p->score)
3055                complete_rewrite = 1;
3056        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
3057}
3058
3059static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3060{
3061        const char *name;
3062        const char *other;
3063        const char *attr_path;
3064
3065        if (DIFF_PAIR_UNMERGED(p)) {
3066                /* unmerged */
3067                return;
3068        }
3069
3070        name = p->one->path;
3071        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3072        attr_path = other ? other : name;
3073
3074        if (o->prefix_length)
3075                strip_prefix(o->prefix_length, &name, &other);
3076
3077        diff_fill_sha1_info(p->one);
3078        diff_fill_sha1_info(p->two);
3079
3080        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3081}
3082
3083void diff_setup(struct diff_options *options)
3084{
3085        memcpy(options, &default_diff_options, sizeof(*options));
3086
3087        options->file = stdout;
3088
3089        options->line_termination = '\n';
3090        options->break_opt = -1;
3091        options->rename_limit = -1;
3092        options->dirstat_permille = diff_dirstat_permille_default;
3093        options->context = 3;
3094
3095        options->change = diff_change;
3096        options->add_remove = diff_addremove;
3097        options->use_color = diff_use_color_default;
3098        options->detect_rename = diff_detect_rename_default;
3099
3100        if (diff_no_prefix) {
3101                options->a_prefix = options->b_prefix = "";
3102        } else if (!diff_mnemonic_prefix) {
3103                options->a_prefix = "a/";
3104                options->b_prefix = "b/";
3105        }
3106}
3107
3108int diff_setup_done(struct diff_options *options)
3109{
3110        int count = 0;
3111
3112        if (options->output_format & DIFF_FORMAT_NAME)
3113                count++;
3114        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3115                count++;
3116        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3117                count++;
3118        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3119                count++;
3120        if (count > 1)
3121                die("--name-only, --name-status, --check and -s are mutually exclusive");
3122
3123        /*
3124         * Most of the time we can say "there are changes"
3125         * only by checking if there are changed paths, but
3126         * --ignore-whitespace* options force us to look
3127         * inside contents.
3128         */
3129
3130        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3131            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3132            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3133                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3134        else
3135                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3136
3137        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3138                options->detect_rename = DIFF_DETECT_COPY;
3139
3140        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3141                options->prefix = NULL;
3142        if (options->prefix)
3143                options->prefix_length = strlen(options->prefix);
3144        else
3145                options->prefix_length = 0;
3146
3147        if (options->output_format & (DIFF_FORMAT_NAME |
3148                                      DIFF_FORMAT_NAME_STATUS |
3149                                      DIFF_FORMAT_CHECKDIFF |
3150                                      DIFF_FORMAT_NO_OUTPUT))
3151                options->output_format &= ~(DIFF_FORMAT_RAW |
3152                                            DIFF_FORMAT_NUMSTAT |
3153                                            DIFF_FORMAT_DIFFSTAT |
3154                                            DIFF_FORMAT_SHORTSTAT |
3155                                            DIFF_FORMAT_DIRSTAT |
3156                                            DIFF_FORMAT_SUMMARY |
3157                                            DIFF_FORMAT_PATCH);
3158
3159        /*
3160         * These cases always need recursive; we do not drop caller-supplied
3161         * recursive bits for other formats here.
3162         */
3163        if (options->output_format & (DIFF_FORMAT_PATCH |
3164                                      DIFF_FORMAT_NUMSTAT |
3165                                      DIFF_FORMAT_DIFFSTAT |
3166                                      DIFF_FORMAT_SHORTSTAT |
3167                                      DIFF_FORMAT_DIRSTAT |
3168                                      DIFF_FORMAT_SUMMARY |
3169                                      DIFF_FORMAT_CHECKDIFF))
3170                DIFF_OPT_SET(options, RECURSIVE);
3171        /*
3172         * Also pickaxe would not work very well if you do not say recursive
3173         */
3174        if (options->pickaxe)
3175                DIFF_OPT_SET(options, RECURSIVE);
3176        /*
3177         * When patches are generated, submodules diffed against the work tree
3178         * must be checked for dirtiness too so it can be shown in the output
3179         */
3180        if (options->output_format & DIFF_FORMAT_PATCH)
3181                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3182
3183        if (options->detect_rename && options->rename_limit < 0)
3184                options->rename_limit = diff_rename_limit_default;
3185        if (options->setup & DIFF_SETUP_USE_CACHE) {
3186                if (!active_cache)
3187                        /* read-cache does not die even when it fails
3188                         * so it is safe for us to do this here.  Also
3189                         * it does not smudge active_cache or active_nr
3190                         * when it fails, so we do not have to worry about
3191                         * cleaning it up ourselves either.
3192                         */
3193                        read_cache();
3194        }
3195        if (options->abbrev <= 0 || 40 < options->abbrev)
3196                options->abbrev = 40; /* full */
3197
3198        /*
3199         * It does not make sense to show the first hit we happened
3200         * to have found.  It does not make sense not to return with
3201         * exit code in such a case either.
3202         */
3203        if (DIFF_OPT_TST(options, QUICK)) {
3204                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3205                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3206        }
3207
3208        return 0;
3209}
3210
3211static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3212{
3213        char c, *eq;
3214        int len;
3215
3216        if (*arg != '-')
3217                return 0;
3218        c = *++arg;
3219        if (!c)
3220                return 0;
3221        if (c == arg_short) {
3222                c = *++arg;
3223                if (!c)
3224                        return 1;
3225                if (val && isdigit(c)) {
3226                        char *end;
3227                        int n = strtoul(arg, &end, 10);
3228                        if (*end)
3229                                return 0;
3230                        *val = n;
3231                        return 1;
3232                }
3233                return 0;
3234        }
3235        if (c != '-')
3236                return 0;
3237        arg++;
3238        eq = strchr(arg, '=');
3239        if (eq)
3240                len = eq - arg;
3241        else
3242                len = strlen(arg);
3243        if (!len || strncmp(arg, arg_long, len))
3244                return 0;
3245        if (eq) {
3246                int n;
3247                char *end;
3248                if (!isdigit(*++eq))
3249                        return 0;
3250                n = strtoul(eq, &end, 10);
3251                if (*end)
3252                        return 0;
3253                *val = n;
3254        }
3255        return 1;
3256}
3257
3258static int diff_scoreopt_parse(const char *opt);
3259
3260static inline int short_opt(char opt, const char **argv,
3261                            const char **optarg)
3262{
3263        const char *arg = argv[0];
3264        if (arg[0] != '-' || arg[1] != opt)
3265                return 0;
3266        if (arg[2] != '\0') {
3267                *optarg = arg + 2;
3268                return 1;
3269        }
3270        if (!argv[1])
3271                die("Option '%c' requires a value", opt);
3272        *optarg = argv[1];
3273        return 2;
3274}
3275
3276int parse_long_opt(const char *opt, const char **argv,
3277                   const char **optarg)
3278{
3279        const char *arg = argv[0];
3280        if (arg[0] != '-' || arg[1] != '-')
3281                return 0;
3282        arg += strlen("--");
3283        if (prefixcmp(arg, opt))
3284                return 0;
3285        arg += strlen(opt);
3286        if (*arg == '=') { /* sticked form: --option=value */
3287                *optarg = arg + 1;
3288                return 1;
3289        }
3290        if (*arg != '\0')
3291                return 0;
3292        /* separate form: --option value */
3293        if (!argv[1])
3294                die("Option '--%s' requires a value", opt);
3295        *optarg = argv[1];
3296        return 2;
3297}
3298
3299static int stat_opt(struct diff_options *options, const char **av)
3300{
3301        const char *arg = av[0];
3302        char *end;
3303        int width = options->stat_width;
3304        int name_width = options->stat_name_width;
3305        int count = options->stat_count;
3306        int argcount = 1;
3307
3308        arg += strlen("--stat");
3309        end = (char *)arg;
3310
3311        switch (*arg) {
3312        case '-':
3313                if (!prefixcmp(arg, "-width")) {
3314                        arg += strlen("-width");
3315                        if (*arg == '=')
3316                                width = strtoul(arg + 1, &end, 10);
3317                        else if (!*arg && !av[1])
3318                                die("Option '--stat-width' requires a value");
3319                        else if (!*arg) {
3320                                width = strtoul(av[1], &end, 10);
3321                                argcount = 2;
3322                        }
3323                } else if (!prefixcmp(arg, "-name-width")) {
3324                        arg += strlen("-name-width");
3325                        if (*arg == '=')
3326                                name_width = strtoul(arg + 1, &end, 10);
3327                        else if (!*arg && !av[1])
3328                                die("Option '--stat-name-width' requires a value");
3329                        else if (!*arg) {
3330                                name_width = strtoul(av[1], &end, 10);
3331                                argcount = 2;
3332                        }
3333                } else if (!prefixcmp(arg, "-count")) {
3334                        arg += strlen("-count");
3335                        if (*arg == '=')
3336                                count = strtoul(arg + 1, &end, 10);
3337                        else if (!*arg && !av[1])
3338                                die("Option '--stat-count' requires a value");
3339                        else if (!*arg) {
3340                                count = strtoul(av[1], &end, 10);
3341                                argcount = 2;
3342                        }
3343                }
3344                break;
3345        case '=':
3346                width = strtoul(arg+1, &end, 10);
3347                if (*end == ',')
3348                        name_width = strtoul(end+1, &end, 10);
3349                if (*end == ',')
3350                        count = strtoul(end+1, &end, 10);
3351        }
3352
3353        /* Important! This checks all the error cases! */
3354        if (*end)
3355                return 0;
3356        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3357        options->stat_name_width = name_width;
3358        options->stat_width = width;
3359        options->stat_count = count;
3360        return argcount;
3361}
3362
3363static int parse_dirstat_opt(struct diff_options *options, const char *params)
3364{
3365        struct strbuf errmsg = STRBUF_INIT;
3366        if (parse_dirstat_params(options, params, &errmsg))
3367                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3368                    errmsg.buf);
3369        strbuf_release(&errmsg);
3370        /*
3371         * The caller knows a dirstat-related option is given from the command
3372         * line; allow it to say "return this_function();"
3373         */
3374        options->output_format |= DIFF_FORMAT_DIRSTAT;
3375        return 1;
3376}
3377
3378int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3379{
3380        const char *arg = av[0];
3381        const char *optarg;
3382        int argcount;
3383
3384        /* Output format options */
3385        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3386                options->output_format |= DIFF_FORMAT_PATCH;
3387        else if (opt_arg(arg, 'U', "unified", &options->context))
3388                options->output_format |= DIFF_FORMAT_PATCH;
3389        else if (!strcmp(arg, "--raw"))
3390                options->output_format |= DIFF_FORMAT_RAW;
3391        else if (!strcmp(arg, "--patch-with-raw"))
3392                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3393        else if (!strcmp(arg, "--numstat"))
3394                options->output_format |= DIFF_FORMAT_NUMSTAT;
3395        else if (!strcmp(arg, "--shortstat"))
3396                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3397        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3398                return parse_dirstat_opt(options, "");
3399        else if (!prefixcmp(arg, "-X"))
3400                return parse_dirstat_opt(options, arg + 2);
3401        else if (!prefixcmp(arg, "--dirstat="))
3402                return parse_dirstat_opt(options, arg + 10);
3403        else if (!strcmp(arg, "--cumulative"))
3404                return parse_dirstat_opt(options, "cumulative");
3405        else if (!strcmp(arg, "--dirstat-by-file"))
3406                return parse_dirstat_opt(options, "files");
3407        else if (!prefixcmp(arg, "--dirstat-by-file=")) {
3408                parse_dirstat_opt(options, "files");
3409                return parse_dirstat_opt(options, arg + 18);
3410        }
3411        else if (!strcmp(arg, "--check"))
3412                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3413        else if (!strcmp(arg, "--summary"))
3414                options->output_format |= DIFF_FORMAT_SUMMARY;
3415        else if (!strcmp(arg, "--patch-with-stat"))
3416                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3417        else if (!strcmp(arg, "--name-only"))
3418                options->output_format |= DIFF_FORMAT_NAME;
3419        else if (!strcmp(arg, "--name-status"))
3420                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3421        else if (!strcmp(arg, "-s"))
3422                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3423        else if (!prefixcmp(arg, "--stat"))
3424                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3425                return stat_opt(options, av);
3426
3427        /* renames options */
3428        else if (!prefixcmp(arg, "-B") || !prefixcmp(arg, "--break-rewrites=") ||
3429                 !strcmp(arg, "--break-rewrites")) {
3430                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3431                        return error("invalid argument to -B: %s", arg+2);
3432        }
3433        else if (!prefixcmp(arg, "-M") || !prefixcmp(arg, "--find-renames=") ||
3434                 !strcmp(arg, "--find-renames")) {
3435                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3436                        return error("invalid argument to -M: %s", arg+2);
3437                options->detect_rename = DIFF_DETECT_RENAME;
3438        }
3439        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3440                options->irreversible_delete = 1;
3441        }
3442        else if (!prefixcmp(arg, "-C") || !prefixcmp(arg, "--find-copies=") ||
3443                 !strcmp(arg, "--find-copies")) {
3444                if (options->detect_rename == DIFF_DETECT_COPY)
3445                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3446                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3447                        return error("invalid argument to -C: %s", arg+2);
3448                options->detect_rename = DIFF_DETECT_COPY;
3449        }
3450        else if (!strcmp(arg, "--no-renames"))
3451                options->detect_rename = 0;
3452        else if (!strcmp(arg, "--relative"))
3453                DIFF_OPT_SET(options, RELATIVE_NAME);
3454        else if (!prefixcmp(arg, "--relative=")) {
3455                DIFF_OPT_SET(options, RELATIVE_NAME);
3456                options->prefix = arg + 11;
3457        }
3458
3459        /* xdiff options */
3460        else if (!strcmp(arg, "--minimal"))
3461                DIFF_XDL_SET(options, NEED_MINIMAL);
3462        else if (!strcmp(arg, "--no-minimal"))
3463                DIFF_XDL_CLR(options, NEED_MINIMAL);
3464        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3465                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3466        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3467                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3468        else if (!strcmp(arg, "--ignore-space-at-eol"))
3469                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3470        else if (!strcmp(arg, "--patience"))
3471                DIFF_XDL_SET(options, PATIENCE_DIFF);
3472        else if (!strcmp(arg, "--histogram"))
3473                DIFF_XDL_SET(options, HISTOGRAM_DIFF);
3474
3475        /* flags options */
3476        else if (!strcmp(arg, "--binary")) {
3477                options->output_format |= DIFF_FORMAT_PATCH;
3478                DIFF_OPT_SET(options, BINARY);
3479        }
3480        else if (!strcmp(arg, "--full-index"))
3481                DIFF_OPT_SET(options, FULL_INDEX);
3482        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3483                DIFF_OPT_SET(options, TEXT);
3484        else if (!strcmp(arg, "-R"))
3485                DIFF_OPT_SET(options, REVERSE_DIFF);
3486        else if (!strcmp(arg, "--find-copies-harder"))
3487                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3488        else if (!strcmp(arg, "--follow"))
3489                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3490        else if (!strcmp(arg, "--color"))
3491                options->use_color = 1;
3492        else if (!prefixcmp(arg, "--color=")) {
3493                int value = git_config_colorbool(NULL, arg+8);
3494                if (value < 0)
3495                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3496                options->use_color = value;
3497        }
3498        else if (!strcmp(arg, "--no-color"))
3499                options->use_color = 0;
3500        else if (!strcmp(arg, "--color-words")) {
3501                options->use_color = 1;
3502                options->word_diff = DIFF_WORDS_COLOR;
3503        }
3504        else if (!prefixcmp(arg, "--color-words=")) {
3505                options->use_color = 1;
3506                options->word_diff = DIFF_WORDS_COLOR;
3507                options->word_regex = arg + 14;
3508        }
3509        else if (!strcmp(arg, "--word-diff")) {
3510                if (options->word_diff == DIFF_WORDS_NONE)
3511                        options->word_diff = DIFF_WORDS_PLAIN;
3512        }
3513        else if (!prefixcmp(arg, "--word-diff=")) {
3514                const char *type = arg + 12;
3515                if (!strcmp(type, "plain"))
3516                        options->word_diff = DIFF_WORDS_PLAIN;
3517                else if (!strcmp(type, "color")) {
3518                        options->use_color = 1;
3519                        options->word_diff = DIFF_WORDS_COLOR;
3520                }
3521                else if (!strcmp(type, "porcelain"))
3522                        options->word_diff = DIFF_WORDS_PORCELAIN;
3523                else if (!strcmp(type, "none"))
3524                        options->word_diff = DIFF_WORDS_NONE;
3525                else
3526                        die("bad --word-diff argument: %s", type);
3527        }
3528        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3529                if (options->word_diff == DIFF_WORDS_NONE)
3530                        options->word_diff = DIFF_WORDS_PLAIN;
3531                options->word_regex = optarg;
3532                return argcount;
3533        }
3534        else if (!strcmp(arg, "--exit-code"))
3535                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3536        else if (!strcmp(arg, "--quiet"))
3537                DIFF_OPT_SET(options, QUICK);
3538        else if (!strcmp(arg, "--ext-diff"))
3539                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3540        else if (!strcmp(arg, "--no-ext-diff"))
3541                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3542        else if (!strcmp(arg, "--textconv"))
3543                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3544        else if (!strcmp(arg, "--no-textconv"))
3545                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3546        else if (!strcmp(arg, "--ignore-submodules")) {
3547                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3548                handle_ignore_submodules_arg(options, "all");
3549        } else if (!prefixcmp(arg, "--ignore-submodules=")) {
3550                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3551                handle_ignore_submodules_arg(options, arg + 20);
3552        } else if (!strcmp(arg, "--submodule"))
3553                DIFF_OPT_SET(options, SUBMODULE_LOG);
3554        else if (!prefixcmp(arg, "--submodule=")) {
3555                if (!strcmp(arg + 12, "log"))
3556                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3557        }
3558
3559        /* misc options */
3560        else if (!strcmp(arg, "-z"))
3561                options->line_termination = 0;
3562        else if ((argcount = short_opt('l', av, &optarg))) {
3563                options->rename_limit = strtoul(optarg, NULL, 10);
3564                return argcount;
3565        }
3566        else if ((argcount = short_opt('S', av, &optarg))) {
3567                options->pickaxe = optarg;
3568                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3569                return argcount;
3570        } else if ((argcount = short_opt('G', av, &optarg))) {
3571                options->pickaxe = optarg;
3572                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3573                return argcount;
3574        }
3575        else if (!strcmp(arg, "--pickaxe-all"))
3576                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3577        else if (!strcmp(arg, "--pickaxe-regex"))
3578                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3579        else if ((argcount = short_opt('O', av, &optarg))) {
3580                options->orderfile = optarg;
3581                return argcount;
3582        }
3583        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3584                options->filter = optarg;
3585                return argcount;
3586        }
3587        else if (!strcmp(arg, "--abbrev"))
3588                options->abbrev = DEFAULT_ABBREV;
3589        else if (!prefixcmp(arg, "--abbrev=")) {
3590                options->abbrev = strtoul(arg + 9, NULL, 10);
3591                if (options->abbrev < MINIMUM_ABBREV)
3592                        options->abbrev = MINIMUM_ABBREV;
3593                else if (40 < options->abbrev)
3594                        options->abbrev = 40;
3595        }
3596        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3597                options->a_prefix = optarg;
3598                return argcount;
3599        }
3600        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3601                options->b_prefix = optarg;
3602                return argcount;
3603        }
3604        else if (!strcmp(arg, "--no-prefix"))
3605                options->a_prefix = options->b_prefix = "";
3606        else if (opt_arg(arg, '\0', "inter-hunk-context",
3607                         &options->interhunkcontext))
3608                ;
3609        else if (!strcmp(arg, "-W"))
3610                DIFF_OPT_SET(options, FUNCCONTEXT);
3611        else if (!strcmp(arg, "--function-context"))
3612                DIFF_OPT_SET(options, FUNCCONTEXT);
3613        else if (!strcmp(arg, "--no-function-context"))
3614                DIFF_OPT_CLR(options, FUNCCONTEXT);
3615        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3616                options->file = fopen(optarg, "w");
3617                if (!options->file)
3618                        die_errno("Could not open '%s'", optarg);
3619                options->close_file = 1;
3620                return argcount;
3621        } else
3622                return 0;
3623        return 1;
3624}
3625
3626int parse_rename_score(const char **cp_p)
3627{
3628        unsigned long num, scale;
3629        int ch, dot;
3630        const char *cp = *cp_p;
3631
3632        num = 0;
3633        scale = 1;
3634        dot = 0;
3635        for (;;) {
3636                ch = *cp;
3637                if ( !dot && ch == '.' ) {
3638                        scale = 1;
3639                        dot = 1;
3640                } else if ( ch == '%' ) {
3641                        scale = dot ? scale*100 : 100;
3642                        cp++;   /* % is always at the end */
3643                        break;
3644                } else if ( ch >= '0' && ch <= '9' ) {
3645                        if ( scale < 100000 ) {
3646                                scale *= 10;
3647                                num = (num*10) + (ch-'0');
3648                        }
3649                } else {
3650                        break;
3651                }
3652                cp++;
3653        }
3654        *cp_p = cp;
3655
3656        /* user says num divided by scale and we say internally that
3657         * is MAX_SCORE * num / scale.
3658         */
3659        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3660}
3661
3662static int diff_scoreopt_parse(const char *opt)
3663{
3664        int opt1, opt2, cmd;
3665
3666        if (*opt++ != '-')
3667                return -1;
3668        cmd = *opt++;
3669        if (cmd == '-') {
3670                /* convert the long-form arguments into short-form versions */
3671                if (!prefixcmp(opt, "break-rewrites")) {
3672                        opt += strlen("break-rewrites");
3673                        if (*opt == 0 || *opt++ == '=')
3674                                cmd = 'B';
3675                } else if (!prefixcmp(opt, "find-copies")) {
3676                        opt += strlen("find-copies");
3677                        if (*opt == 0 || *opt++ == '=')
3678                                cmd = 'C';
3679                } else if (!prefixcmp(opt, "find-renames")) {
3680                        opt += strlen("find-renames");
3681                        if (*opt == 0 || *opt++ == '=')
3682                                cmd = 'M';
3683                }
3684        }
3685        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3686                return -1; /* that is not a -M, -C nor -B option */
3687
3688        opt1 = parse_rename_score(&opt);
3689        if (cmd != 'B')
3690                opt2 = 0;
3691        else {
3692                if (*opt == 0)
3693                        opt2 = 0;
3694                else if (*opt != '/')
3695                        return -1; /* we expect -B80/99 or -B80 */
3696                else {
3697                        opt++;
3698                        opt2 = parse_rename_score(&opt);
3699                }
3700        }
3701        if (*opt != 0)
3702                return -1;
3703        return opt1 | (opt2 << 16);
3704}
3705
3706struct diff_queue_struct diff_queued_diff;
3707
3708void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3709{
3710        if (queue->alloc <= queue->nr) {
3711                queue->alloc = alloc_nr(queue->alloc);
3712                queue->queue = xrealloc(queue->queue,
3713                                        sizeof(dp) * queue->alloc);
3714        }
3715        queue->queue[queue->nr++] = dp;
3716}
3717
3718struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3719                                 struct diff_filespec *one,
3720                                 struct diff_filespec *two)
3721{
3722        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3723        dp->one = one;
3724        dp->two = two;
3725        if (queue)
3726                diff_q(queue, dp);
3727        return dp;
3728}
3729
3730void diff_free_filepair(struct diff_filepair *p)
3731{
3732        free_filespec(p->one);
3733        free_filespec(p->two);
3734        free(p);
3735}
3736
3737/* This is different from find_unique_abbrev() in that
3738 * it stuffs the result with dots for alignment.
3739 */
3740const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3741{
3742        int abblen;
3743        const char *abbrev;
3744        if (len == 40)
3745                return sha1_to_hex(sha1);
3746
3747        abbrev = find_unique_abbrev(sha1, len);
3748        abblen = strlen(abbrev);
3749        if (abblen < 37) {
3750                static char hex[41];
3751                if (len < abblen && abblen <= len + 2)
3752                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3753                else
3754                        sprintf(hex, "%s...", abbrev);
3755                return hex;
3756        }
3757        return sha1_to_hex(sha1);
3758}
3759
3760static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3761{
3762        int line_termination = opt->line_termination;
3763        int inter_name_termination = line_termination ? '\t' : '\0';
3764        if (opt->output_prefix) {
3765                struct strbuf *msg = NULL;
3766                msg = opt->output_prefix(opt, opt->output_prefix_data);
3767                fprintf(opt->file, "%s", msg->buf);
3768        }
3769
3770        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3771                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3772                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3773                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3774        }
3775        if (p->score) {
3776                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3777                        inter_name_termination);
3778        } else {
3779                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3780        }
3781
3782        if (p->status == DIFF_STATUS_COPIED ||
3783            p->status == DIFF_STATUS_RENAMED) {
3784                const char *name_a, *name_b;
3785                name_a = p->one->path;
3786                name_b = p->two->path;
3787                strip_prefix(opt->prefix_length, &name_a, &name_b);
3788                write_name_quoted(name_a, opt->file, inter_name_termination);
3789                write_name_quoted(name_b, opt->file, line_termination);
3790        } else {
3791                const char *name_a, *name_b;
3792                name_a = p->one->mode ? p->one->path : 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, line_termination);
3796        }
3797}
3798
3799int diff_unmodified_pair(struct diff_filepair *p)
3800{
3801        /* This function is written stricter than necessary to support
3802         * the currently implemented transformers, but the idea is to
3803         * let transformers to produce diff_filepairs any way they want,
3804         * and filter and clean them up here before producing the output.
3805         */
3806        struct diff_filespec *one = p->one, *two = p->two;
3807
3808        if (DIFF_PAIR_UNMERGED(p))
3809                return 0; /* unmerged is interesting */
3810
3811        /* deletion, addition, mode or type change
3812         * and rename are all interesting.
3813         */
3814        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3815            DIFF_PAIR_MODE_CHANGED(p) ||
3816            strcmp(one->path, two->path))
3817                return 0;
3818
3819        /* both are valid and point at the same path.  that is, we are
3820         * dealing with a change.
3821         */
3822        if (one->sha1_valid && two->sha1_valid &&
3823            !hashcmp(one->sha1, two->sha1) &&
3824            !one->dirty_submodule && !two->dirty_submodule)
3825                return 1; /* no change */
3826        if (!one->sha1_valid && !two->sha1_valid)
3827                return 1; /* both look at the same file on the filesystem. */
3828        return 0;
3829}
3830
3831static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3832{
3833        if (diff_unmodified_pair(p))
3834                return;
3835
3836        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3837            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3838                return; /* no tree diffs in patch format */
3839
3840        run_diff(p, o);
3841}
3842
3843static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3844                            struct diffstat_t *diffstat)
3845{
3846        if (diff_unmodified_pair(p))
3847                return;
3848
3849        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3850            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3851                return; /* no useful stat for tree diffs */
3852
3853        run_diffstat(p, o, diffstat);
3854}
3855
3856static void diff_flush_checkdiff(struct diff_filepair *p,
3857                struct diff_options *o)
3858{
3859        if (diff_unmodified_pair(p))
3860                return;
3861
3862        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3863            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3864                return; /* nothing to check in tree diffs */
3865
3866        run_checkdiff(p, o);
3867}
3868
3869int diff_queue_is_empty(void)
3870{
3871        struct diff_queue_struct *q = &diff_queued_diff;
3872        int i;
3873        for (i = 0; i < q->nr; i++)
3874                if (!diff_unmodified_pair(q->queue[i]))
3875                        return 0;
3876        return 1;
3877}
3878
3879#if DIFF_DEBUG
3880void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3881{
3882        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3883                x, one ? one : "",
3884                s->path,
3885                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3886                s->mode,
3887                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3888        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3889                x, one ? one : "",
3890                s->size, s->xfrm_flags);
3891}
3892
3893void diff_debug_filepair(const struct diff_filepair *p, int i)
3894{
3895        diff_debug_filespec(p->one, i, "one");
3896        diff_debug_filespec(p->two, i, "two");
3897        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3898                p->score, p->status ? p->status : '?',
3899                p->one->rename_used, p->broken_pair);
3900}
3901
3902void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3903{
3904        int i;
3905        if (msg)
3906                fprintf(stderr, "%s\n", msg);
3907        fprintf(stderr, "q->nr = %d\n", q->nr);
3908        for (i = 0; i < q->nr; i++) {
3909                struct diff_filepair *p = q->queue[i];
3910                diff_debug_filepair(p, i);
3911        }
3912}
3913#endif
3914
3915static void diff_resolve_rename_copy(void)
3916{
3917        int i;
3918        struct diff_filepair *p;
3919        struct diff_queue_struct *q = &diff_queued_diff;
3920
3921        diff_debug_queue("resolve-rename-copy", q);
3922
3923        for (i = 0; i < q->nr; i++) {
3924                p = q->queue[i];
3925                p->status = 0; /* undecided */
3926                if (DIFF_PAIR_UNMERGED(p))
3927                        p->status = DIFF_STATUS_UNMERGED;
3928                else if (!DIFF_FILE_VALID(p->one))
3929                        p->status = DIFF_STATUS_ADDED;
3930                else if (!DIFF_FILE_VALID(p->two))
3931                        p->status = DIFF_STATUS_DELETED;
3932                else if (DIFF_PAIR_TYPE_CHANGED(p))
3933                        p->status = DIFF_STATUS_TYPE_CHANGED;
3934
3935                /* from this point on, we are dealing with a pair
3936                 * whose both sides are valid and of the same type, i.e.
3937                 * either in-place edit or rename/copy edit.
3938                 */
3939                else if (DIFF_PAIR_RENAME(p)) {
3940                        /*
3941                         * A rename might have re-connected a broken
3942                         * pair up, causing the pathnames to be the
3943                         * same again. If so, that's not a rename at
3944                         * all, just a modification..
3945                         *
3946                         * Otherwise, see if this source was used for
3947                         * multiple renames, in which case we decrement
3948                         * the count, and call it a copy.
3949                         */
3950                        if (!strcmp(p->one->path, p->two->path))
3951                                p->status = DIFF_STATUS_MODIFIED;
3952                        else if (--p->one->rename_used > 0)
3953                                p->status = DIFF_STATUS_COPIED;
3954                        else
3955                                p->status = DIFF_STATUS_RENAMED;
3956                }
3957                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3958                         p->one->mode != p->two->mode ||
3959                         p->one->dirty_submodule ||
3960                         p->two->dirty_submodule ||
3961                         is_null_sha1(p->one->sha1))
3962                        p->status = DIFF_STATUS_MODIFIED;
3963                else {
3964                        /* This is a "no-change" entry and should not
3965                         * happen anymore, but prepare for broken callers.
3966                         */
3967                        error("feeding unmodified %s to diffcore",
3968                              p->one->path);
3969                        p->status = DIFF_STATUS_UNKNOWN;
3970                }
3971        }
3972        diff_debug_queue("resolve-rename-copy done", q);
3973}
3974
3975static int check_pair_status(struct diff_filepair *p)
3976{
3977        switch (p->status) {
3978        case DIFF_STATUS_UNKNOWN:
3979                return 0;
3980        case 0:
3981                die("internal error in diff-resolve-rename-copy");
3982        default:
3983                return 1;
3984        }
3985}
3986
3987static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3988{
3989        int fmt = opt->output_format;
3990
3991        if (fmt & DIFF_FORMAT_CHECKDIFF)
3992                diff_flush_checkdiff(p, opt);
3993        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3994                diff_flush_raw(p, opt);
3995        else if (fmt & DIFF_FORMAT_NAME) {
3996                const char *name_a, *name_b;
3997                name_a = p->two->path;
3998                name_b = NULL;
3999                strip_prefix(opt->prefix_length, &name_a, &name_b);
4000                write_name_quoted(name_a, opt->file, opt->line_termination);
4001        }
4002}
4003
4004static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4005{
4006        if (fs->mode)
4007                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4008        else
4009                fprintf(file, " %s ", newdelete);
4010        write_name_quoted(fs->path, file, '\n');
4011}
4012
4013
4014static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4015                const char *line_prefix)
4016{
4017        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4018                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4019                        p->two->mode, show_name ? ' ' : '\n');
4020                if (show_name) {
4021                        write_name_quoted(p->two->path, file, '\n');
4022                }
4023        }
4024}
4025
4026static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4027                        const char *line_prefix)
4028{
4029        char *names = pprint_rename(p->one->path, p->two->path);
4030
4031        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4032        free(names);
4033        show_mode_change(file, p, 0, line_prefix);
4034}
4035
4036static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4037{
4038        FILE *file = opt->file;
4039        char *line_prefix = "";
4040
4041        if (opt->output_prefix) {
4042                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
4043                line_prefix = buf->buf;
4044        }
4045
4046        switch(p->status) {
4047        case DIFF_STATUS_DELETED:
4048                fputs(line_prefix, file);
4049                show_file_mode_name(file, "delete", p->one);
4050                break;
4051        case DIFF_STATUS_ADDED:
4052                fputs(line_prefix, file);
4053                show_file_mode_name(file, "create", p->two);
4054                break;
4055        case DIFF_STATUS_COPIED:
4056                fputs(line_prefix, file);
4057                show_rename_copy(file, "copy", p, line_prefix);
4058                break;
4059        case DIFF_STATUS_RENAMED:
4060                fputs(line_prefix, file);
4061                show_rename_copy(file, "rename", p, line_prefix);
4062                break;
4063        default:
4064                if (p->score) {
4065                        fprintf(file, "%s rewrite ", line_prefix);
4066                        write_name_quoted(p->two->path, file, ' ');
4067                        fprintf(file, "(%d%%)\n", similarity_index(p));
4068                }
4069                show_mode_change(file, p, !p->score, line_prefix);
4070                break;
4071        }
4072}
4073
4074struct patch_id_t {
4075        git_SHA_CTX *ctx;
4076        int patchlen;
4077};
4078
4079static int remove_space(char *line, int len)
4080{
4081        int i;
4082        char *dst = line;
4083        unsigned char c;
4084
4085        for (i = 0; i < len; i++)
4086                if (!isspace((c = line[i])))
4087                        *dst++ = c;
4088
4089        return dst - line;
4090}
4091
4092static void patch_id_consume(void *priv, char *line, unsigned long len)
4093{
4094        struct patch_id_t *data = priv;
4095        int new_len;
4096
4097        /* Ignore line numbers when computing the SHA1 of the patch */
4098        if (!prefixcmp(line, "@@ -"))
4099                return;
4100
4101        new_len = remove_space(line, len);
4102
4103        git_SHA1_Update(data->ctx, line, new_len);
4104        data->patchlen += new_len;
4105}
4106
4107/* returns 0 upon success, and writes result into sha1 */
4108static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
4109{
4110        struct diff_queue_struct *q = &diff_queued_diff;
4111        int i;
4112        git_SHA_CTX ctx;
4113        struct patch_id_t data;
4114        char buffer[PATH_MAX * 4 + 20];
4115
4116        git_SHA1_Init(&ctx);
4117        memset(&data, 0, sizeof(struct patch_id_t));
4118        data.ctx = &ctx;
4119
4120        for (i = 0; i < q->nr; i++) {
4121                xpparam_t xpp;
4122                xdemitconf_t xecfg;
4123                mmfile_t mf1, mf2;
4124                struct diff_filepair *p = q->queue[i];
4125                int len1, len2;
4126
4127                memset(&xpp, 0, sizeof(xpp));
4128                memset(&xecfg, 0, sizeof(xecfg));
4129                if (p->status == 0)
4130                        return error("internal diff status error");
4131                if (p->status == DIFF_STATUS_UNKNOWN)
4132                        continue;
4133                if (diff_unmodified_pair(p))
4134                        continue;
4135                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4136                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4137                        continue;
4138                if (DIFF_PAIR_UNMERGED(p))
4139                        continue;
4140
4141                diff_fill_sha1_info(p->one);
4142                diff_fill_sha1_info(p->two);
4143                if (fill_mmfile(&mf1, p->one) < 0 ||
4144                                fill_mmfile(&mf2, p->two) < 0)
4145                        return error("unable to read files to diff");
4146
4147                len1 = remove_space(p->one->path, strlen(p->one->path));
4148                len2 = remove_space(p->two->path, strlen(p->two->path));
4149                if (p->one->mode == 0)
4150                        len1 = snprintf(buffer, sizeof(buffer),
4151                                        "diff--gita/%.*sb/%.*s"
4152                                        "newfilemode%06o"
4153                                        "---/dev/null"
4154                                        "+++b/%.*s",
4155                                        len1, p->one->path,
4156                                        len2, p->two->path,
4157                                        p->two->mode,
4158                                        len2, p->two->path);
4159                else if (p->two->mode == 0)
4160                        len1 = snprintf(buffer, sizeof(buffer),
4161                                        "diff--gita/%.*sb/%.*s"
4162                                        "deletedfilemode%06o"
4163                                        "---a/%.*s"
4164                                        "+++/dev/null",
4165                                        len1, p->one->path,
4166                                        len2, p->two->path,
4167                                        p->one->mode,
4168                                        len1, p->one->path);
4169                else
4170                        len1 = snprintf(buffer, sizeof(buffer),
4171                                        "diff--gita/%.*sb/%.*s"
4172                                        "---a/%.*s"
4173                                        "+++b/%.*s",
4174                                        len1, p->one->path,
4175                                        len2, p->two->path,
4176                                        len1, p->one->path,
4177                                        len2, p->two->path);
4178                git_SHA1_Update(&ctx, buffer, len1);
4179
4180                if (diff_filespec_is_binary(p->one) ||
4181                    diff_filespec_is_binary(p->two)) {
4182                        git_SHA1_Update(&ctx, sha1_to_hex(p->one->sha1), 40);
4183                        git_SHA1_Update(&ctx, sha1_to_hex(p->two->sha1), 40);
4184                        continue;
4185                }
4186
4187                xpp.flags = 0;
4188                xecfg.ctxlen = 3;
4189                xecfg.flags = 0;
4190                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4191                              &xpp, &xecfg);
4192        }
4193
4194        git_SHA1_Final(sha1, &ctx);
4195        return 0;
4196}
4197
4198int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
4199{
4200        struct diff_queue_struct *q = &diff_queued_diff;
4201        int i;
4202        int result = diff_get_patch_id(options, sha1);
4203
4204        for (i = 0; i < q->nr; i++)
4205                diff_free_filepair(q->queue[i]);
4206
4207        free(q->queue);
4208        DIFF_QUEUE_CLEAR(q);
4209
4210        return result;
4211}
4212
4213static int is_summary_empty(const struct diff_queue_struct *q)
4214{
4215        int i;
4216
4217        for (i = 0; i < q->nr; i++) {
4218                const struct diff_filepair *p = q->queue[i];
4219
4220                switch (p->status) {
4221                case DIFF_STATUS_DELETED:
4222                case DIFF_STATUS_ADDED:
4223                case DIFF_STATUS_COPIED:
4224                case DIFF_STATUS_RENAMED:
4225                        return 0;
4226                default:
4227                        if (p->score)
4228                                return 0;
4229                        if (p->one->mode && p->two->mode &&
4230                            p->one->mode != p->two->mode)
4231                                return 0;
4232                        break;
4233                }
4234        }
4235        return 1;
4236}
4237
4238static const char rename_limit_warning[] =
4239"inexact rename detection was skipped due to too many files.";
4240
4241static const char degrade_cc_to_c_warning[] =
4242"only found copies from modified paths due to too many files.";
4243
4244static const char rename_limit_advice[] =
4245"you may want to set your %s variable to at least "
4246"%d and retry the command.";
4247
4248void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4249{
4250        if (degraded_cc)
4251                warning(degrade_cc_to_c_warning);
4252        else if (needed)
4253                warning(rename_limit_warning);
4254        else
4255                return;
4256        if (0 < needed && needed < 32767)
4257                warning(rename_limit_advice, varname, needed);
4258}
4259
4260void diff_flush(struct diff_options *options)
4261{
4262        struct diff_queue_struct *q = &diff_queued_diff;
4263        int i, output_format = options->output_format;
4264        int separator = 0;
4265        int dirstat_by_line = 0;
4266
4267        /*
4268         * Order: raw, stat, summary, patch
4269         * or:    name/name-status/checkdiff (other bits clear)
4270         */
4271        if (!q->nr)
4272                goto free_queue;
4273
4274        if (output_format & (DIFF_FORMAT_RAW |
4275                             DIFF_FORMAT_NAME |
4276                             DIFF_FORMAT_NAME_STATUS |
4277                             DIFF_FORMAT_CHECKDIFF)) {
4278                for (i = 0; i < q->nr; i++) {
4279                        struct diff_filepair *p = q->queue[i];
4280                        if (check_pair_status(p))
4281                                flush_one_pair(p, options);
4282                }
4283                separator++;
4284        }
4285
4286        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4287                dirstat_by_line = 1;
4288
4289        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4290            dirstat_by_line) {
4291                struct diffstat_t diffstat;
4292
4293                memset(&diffstat, 0, sizeof(struct diffstat_t));
4294                for (i = 0; i < q->nr; i++) {
4295                        struct diff_filepair *p = q->queue[i];
4296                        if (check_pair_status(p))
4297                                diff_flush_stat(p, options, &diffstat);
4298                }
4299                if (output_format & DIFF_FORMAT_NUMSTAT)
4300                        show_numstat(&diffstat, options);
4301                if (output_format & DIFF_FORMAT_DIFFSTAT)
4302                        show_stats(&diffstat, options);
4303                if (output_format & DIFF_FORMAT_SHORTSTAT)
4304                        show_shortstats(&diffstat, options);
4305                if (output_format & DIFF_FORMAT_DIRSTAT)
4306                        show_dirstat_by_line(&diffstat, options);
4307                free_diffstat_info(&diffstat);
4308                separator++;
4309        }
4310        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4311                show_dirstat(options);
4312
4313        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4314                for (i = 0; i < q->nr; i++) {
4315                        diff_summary(options, q->queue[i]);
4316                }
4317                separator++;
4318        }
4319
4320        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4321            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4322            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4323                /*
4324                 * run diff_flush_patch for the exit status. setting
4325                 * options->file to /dev/null should be safe, becaue we
4326                 * aren't supposed to produce any output anyway.
4327                 */
4328                if (options->close_file)
4329                        fclose(options->file);
4330                options->file = fopen("/dev/null", "w");
4331                if (!options->file)
4332                        die_errno("Could not open /dev/null");
4333                options->close_file = 1;
4334                for (i = 0; i < q->nr; i++) {
4335                        struct diff_filepair *p = q->queue[i];
4336                        if (check_pair_status(p))
4337                                diff_flush_patch(p, options);
4338                        if (options->found_changes)
4339                                break;
4340                }
4341        }
4342
4343        if (output_format & DIFF_FORMAT_PATCH) {
4344                if (separator) {
4345                        putc(options->line_termination, options->file);
4346                        if (options->stat_sep) {
4347                                /* attach patch instead of inline */
4348                                fputs(options->stat_sep, options->file);
4349                        }
4350                }
4351
4352                for (i = 0; i < q->nr; i++) {
4353                        struct diff_filepair *p = q->queue[i];
4354                        if (check_pair_status(p))
4355                                diff_flush_patch(p, options);
4356                }
4357        }
4358
4359        if (output_format & DIFF_FORMAT_CALLBACK)
4360                options->format_callback(q, options, options->format_callback_data);
4361
4362        for (i = 0; i < q->nr; i++)
4363                diff_free_filepair(q->queue[i]);
4364free_queue:
4365        free(q->queue);
4366        DIFF_QUEUE_CLEAR(q);
4367        if (options->close_file)
4368                fclose(options->file);
4369
4370        /*
4371         * Report the content-level differences with HAS_CHANGES;
4372         * diff_addremove/diff_change does not set the bit when
4373         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4374         */
4375        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4376                if (options->found_changes)
4377                        DIFF_OPT_SET(options, HAS_CHANGES);
4378                else
4379                        DIFF_OPT_CLR(options, HAS_CHANGES);
4380        }
4381}
4382
4383static void diffcore_apply_filter(const char *filter)
4384{
4385        int i;
4386        struct diff_queue_struct *q = &diff_queued_diff;
4387        struct diff_queue_struct outq;
4388        DIFF_QUEUE_CLEAR(&outq);
4389
4390        if (!filter)
4391                return;
4392
4393        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
4394                int found;
4395                for (i = found = 0; !found && i < q->nr; i++) {
4396                        struct diff_filepair *p = q->queue[i];
4397                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4398                             ((p->score &&
4399                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4400                              (!p->score &&
4401                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4402                            ((p->status != DIFF_STATUS_MODIFIED) &&
4403                             strchr(filter, p->status)))
4404                                found++;
4405                }
4406                if (found)
4407                        return;
4408
4409                /* otherwise we will clear the whole queue
4410                 * by copying the empty outq at the end of this
4411                 * function, but first clear the current entries
4412                 * in the queue.
4413                 */
4414                for (i = 0; i < q->nr; i++)
4415                        diff_free_filepair(q->queue[i]);
4416        }
4417        else {
4418                /* Only the matching ones */
4419                for (i = 0; i < q->nr; i++) {
4420                        struct diff_filepair *p = q->queue[i];
4421
4422                        if (((p->status == DIFF_STATUS_MODIFIED) &&
4423                             ((p->score &&
4424                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
4425                              (!p->score &&
4426                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
4427                            ((p->status != DIFF_STATUS_MODIFIED) &&
4428                             strchr(filter, p->status)))
4429                                diff_q(&outq, p);
4430                        else
4431                                diff_free_filepair(p);
4432                }
4433        }
4434        free(q->queue);
4435        *q = outq;
4436}
4437
4438/* Check whether two filespecs with the same mode and size are identical */
4439static int diff_filespec_is_identical(struct diff_filespec *one,
4440                                      struct diff_filespec *two)
4441{
4442        if (S_ISGITLINK(one->mode))
4443                return 0;
4444        if (diff_populate_filespec(one, 0))
4445                return 0;
4446        if (diff_populate_filespec(two, 0))
4447                return 0;
4448        return !memcmp(one->data, two->data, one->size);
4449}
4450
4451static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4452{
4453        int i;
4454        struct diff_queue_struct *q = &diff_queued_diff;
4455        struct diff_queue_struct outq;
4456        DIFF_QUEUE_CLEAR(&outq);
4457
4458        for (i = 0; i < q->nr; i++) {
4459                struct diff_filepair *p = q->queue[i];
4460
4461                /*
4462                 * 1. Entries that come from stat info dirtiness
4463                 *    always have both sides (iow, not create/delete),
4464                 *    one side of the object name is unknown, with
4465                 *    the same mode and size.  Keep the ones that
4466                 *    do not match these criteria.  They have real
4467                 *    differences.
4468                 *
4469                 * 2. At this point, the file is known to be modified,
4470                 *    with the same mode and size, and the object
4471                 *    name of one side is unknown.  Need to inspect
4472                 *    the identical contents.
4473                 */
4474                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4475                    !DIFF_FILE_VALID(p->two) ||
4476                    (p->one->sha1_valid && p->two->sha1_valid) ||
4477                    (p->one->mode != p->two->mode) ||
4478                    diff_populate_filespec(p->one, 1) ||
4479                    diff_populate_filespec(p->two, 1) ||
4480                    (p->one->size != p->two->size) ||
4481                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4482                        diff_q(&outq, p);
4483                else {
4484                        /*
4485                         * The caller can subtract 1 from skip_stat_unmatch
4486                         * to determine how many paths were dirty only
4487                         * due to stat info mismatch.
4488                         */
4489                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4490                                diffopt->skip_stat_unmatch++;
4491                        diff_free_filepair(p);
4492                }
4493        }
4494        free(q->queue);
4495        *q = outq;
4496}
4497
4498static int diffnamecmp(const void *a_, const void *b_)
4499{
4500        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4501        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4502        const char *name_a, *name_b;
4503
4504        name_a = a->one ? a->one->path : a->two->path;
4505        name_b = b->one ? b->one->path : b->two->path;
4506        return strcmp(name_a, name_b);
4507}
4508
4509void diffcore_fix_diff_index(struct diff_options *options)
4510{
4511        struct diff_queue_struct *q = &diff_queued_diff;
4512        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4513}
4514
4515void diffcore_std(struct diff_options *options)
4516{
4517        if (options->skip_stat_unmatch)
4518                diffcore_skip_stat_unmatch(options);
4519        if (!options->found_follow) {
4520                /* See try_to_follow_renames() in tree-diff.c */
4521                if (options->break_opt != -1)
4522                        diffcore_break(options->break_opt);
4523                if (options->detect_rename)
4524                        diffcore_rename(options);
4525                if (options->break_opt != -1)
4526                        diffcore_merge_broken();
4527        }
4528        if (options->pickaxe)
4529                diffcore_pickaxe(options);
4530        if (options->orderfile)
4531                diffcore_order(options->orderfile);
4532        if (!options->found_follow)
4533                /* See try_to_follow_renames() in tree-diff.c */
4534                diff_resolve_rename_copy();
4535        diffcore_apply_filter(options->filter);
4536
4537        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4538                DIFF_OPT_SET(options, HAS_CHANGES);
4539        else
4540                DIFF_OPT_CLR(options, HAS_CHANGES);
4541
4542        options->found_follow = 0;
4543}
4544
4545int diff_result_code(struct diff_options *opt, int status)
4546{
4547        int result = 0;
4548
4549        diff_warn_rename_limit("diff.renamelimit",
4550                               opt->needed_rename_limit,
4551                               opt->degraded_cc_to_c);
4552        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4553            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4554                return status;
4555        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4556            DIFF_OPT_TST(opt, HAS_CHANGES))
4557                result |= 01;
4558        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4559            DIFF_OPT_TST(opt, CHECK_FAILED))
4560                result |= 02;
4561        return result;
4562}
4563
4564int diff_can_quit_early(struct diff_options *opt)
4565{
4566        return (DIFF_OPT_TST(opt, QUICK) &&
4567                !opt->filter &&
4568                DIFF_OPT_TST(opt, HAS_CHANGES));
4569}
4570
4571/*
4572 * Shall changes to this submodule be ignored?
4573 *
4574 * Submodule changes can be configured to be ignored separately for each path,
4575 * but that configuration can be overridden from the command line.
4576 */
4577static int is_submodule_ignored(const char *path, struct diff_options *options)
4578{
4579        int ignored = 0;
4580        unsigned orig_flags = options->flags;
4581        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4582                set_diffopt_flags_from_submodule_config(options, path);
4583        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4584                ignored = 1;
4585        options->flags = orig_flags;
4586        return ignored;
4587}
4588
4589void diff_addremove(struct diff_options *options,
4590                    int addremove, unsigned mode,
4591                    const unsigned char *sha1,
4592                    const char *concatpath, unsigned dirty_submodule)
4593{
4594        struct diff_filespec *one, *two;
4595
4596        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4597                return;
4598
4599        /* This may look odd, but it is a preparation for
4600         * feeding "there are unchanged files which should
4601         * not produce diffs, but when you are doing copy
4602         * detection you would need them, so here they are"
4603         * entries to the diff-core.  They will be prefixed
4604         * with something like '=' or '*' (I haven't decided
4605         * which but should not make any difference).
4606         * Feeding the same new and old to diff_change()
4607         * also has the same effect.
4608         * Before the final output happens, they are pruned after
4609         * merged into rename/copy pairs as appropriate.
4610         */
4611        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4612                addremove = (addremove == '+' ? '-' :
4613                             addremove == '-' ? '+' : addremove);
4614
4615        if (options->prefix &&
4616            strncmp(concatpath, options->prefix, options->prefix_length))
4617                return;
4618
4619        one = alloc_filespec(concatpath);
4620        two = alloc_filespec(concatpath);
4621
4622        if (addremove != '+')
4623                fill_filespec(one, sha1, mode);
4624        if (addremove != '-') {
4625                fill_filespec(two, sha1, mode);
4626                two->dirty_submodule = dirty_submodule;
4627        }
4628
4629        diff_queue(&diff_queued_diff, one, two);
4630        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4631                DIFF_OPT_SET(options, HAS_CHANGES);
4632}
4633
4634void diff_change(struct diff_options *options,
4635                 unsigned old_mode, unsigned new_mode,
4636                 const unsigned char *old_sha1,
4637                 const unsigned char *new_sha1,
4638                 const char *concatpath,
4639                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4640{
4641        struct diff_filespec *one, *two;
4642
4643        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
4644            is_submodule_ignored(concatpath, options))
4645                return;
4646
4647        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4648                unsigned tmp;
4649                const unsigned char *tmp_c;
4650                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4651                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4652                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4653                        new_dirty_submodule = tmp;
4654        }
4655
4656        if (options->prefix &&
4657            strncmp(concatpath, options->prefix, options->prefix_length))
4658                return;
4659
4660        one = alloc_filespec(concatpath);
4661        two = alloc_filespec(concatpath);
4662        fill_filespec(one, old_sha1, old_mode);
4663        fill_filespec(two, new_sha1, new_mode);
4664        one->dirty_submodule = old_dirty_submodule;
4665        two->dirty_submodule = new_dirty_submodule;
4666
4667        diff_queue(&diff_queued_diff, one, two);
4668        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4669                DIFF_OPT_SET(options, HAS_CHANGES);
4670}
4671
4672struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
4673{
4674        struct diff_filepair *pair;
4675        struct diff_filespec *one, *two;
4676
4677        if (options->prefix &&
4678            strncmp(path, options->prefix, options->prefix_length))
4679                return NULL;
4680
4681        one = alloc_filespec(path);
4682        two = alloc_filespec(path);
4683        pair = diff_queue(&diff_queued_diff, one, two);
4684        pair->is_unmerged = 1;
4685        return pair;
4686}
4687
4688static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4689                size_t *outsize)
4690{
4691        struct diff_tempfile *temp;
4692        const char *argv[3];
4693        const char **arg = argv;
4694        struct child_process child;
4695        struct strbuf buf = STRBUF_INIT;
4696        int err = 0;
4697
4698        temp = prepare_temp_file(spec->path, spec);
4699        *arg++ = pgm;
4700        *arg++ = temp->name;
4701        *arg = NULL;
4702
4703        memset(&child, 0, sizeof(child));
4704        child.use_shell = 1;
4705        child.argv = argv;
4706        child.out = -1;
4707        if (start_command(&child)) {
4708                remove_tempfile();
4709                return NULL;
4710        }
4711
4712        if (strbuf_read(&buf, child.out, 0) < 0)
4713                err = error("error reading from textconv command '%s'", pgm);
4714        close(child.out);
4715
4716        if (finish_command(&child) || err) {
4717                strbuf_release(&buf);
4718                remove_tempfile();
4719                return NULL;
4720        }
4721        remove_tempfile();
4722
4723        return strbuf_detach(&buf, outsize);
4724}
4725
4726size_t fill_textconv(struct userdiff_driver *driver,
4727                     struct diff_filespec *df,
4728                     char **outbuf)
4729{
4730        size_t size;
4731
4732        if (!driver || !driver->textconv) {
4733                if (!DIFF_FILE_VALID(df)) {
4734                        *outbuf = "";
4735                        return 0;
4736                }
4737                if (diff_populate_filespec(df, 0))
4738                        die("unable to read files to diff");
4739                *outbuf = df->data;
4740                return df->size;
4741        }
4742
4743        if (driver->textconv_cache && df->sha1_valid) {
4744                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4745                                          &size);
4746                if (*outbuf)
4747                        return size;
4748        }
4749
4750        *outbuf = run_textconv(driver->textconv, df, &size);
4751        if (!*outbuf)
4752                die("unable to read files to diff");
4753
4754        if (driver->textconv_cache && df->sha1_valid) {
4755                /* ignore errors, as we might be in a readonly repository */
4756                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4757                                size);
4758                /*
4759                 * we could save up changes and flush them all at the end,
4760                 * but we would need an extra call after all diffing is done.
4761                 * Since generating a cache entry is the slow path anyway,
4762                 * this extra overhead probably isn't a big deal.
4763                 */
4764                notes_cache_write(driver->textconv_cache);
4765        }
4766
4767        return size;
4768}