diff.con commit Merge branch 'jc/worktree-config' (ed0006a)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "tempfile.h"
   6#include "quote.h"
   7#include "diff.h"
   8#include "diffcore.h"
   9#include "delta.h"
  10#include "xdiff-interface.h"
  11#include "color.h"
  12#include "attr.h"
  13#include "run-command.h"
  14#include "utf8.h"
  15#include "userdiff.h"
  16#include "submodule-config.h"
  17#include "submodule.h"
  18#include "ll-merge.h"
  19#include "string-list.h"
  20#include "argv-array.h"
  21#include "graph.h"
  22
  23#ifdef NO_FAST_WORKING_DIRECTORY
  24#define FAST_WORKING_DIRECTORY 0
  25#else
  26#define FAST_WORKING_DIRECTORY 1
  27#endif
  28
  29static int diff_detect_rename_default;
  30static int diff_indent_heuristic; /* experimental */
  31static int diff_compaction_heuristic; /* experimental */
  32static int diff_rename_limit_default = 400;
  33static int diff_suppress_blank_empty;
  34static int diff_use_color_default = -1;
  35static int diff_context_default = 3;
  36static const char *diff_word_regex_cfg;
  37static const char *external_diff_cmd_cfg;
  38static const char *diff_order_file_cfg;
  39int diff_auto_refresh_index = 1;
  40static int diff_mnemonic_prefix;
  41static int diff_no_prefix;
  42static int diff_stat_graph_width;
  43static int diff_dirstat_permille_default = 30;
  44static struct diff_options default_diff_options;
  45static long diff_algorithm;
  46
  47static char diff_colors[][COLOR_MAXLEN] = {
  48        GIT_COLOR_RESET,
  49        GIT_COLOR_NORMAL,       /* CONTEXT */
  50        GIT_COLOR_BOLD,         /* METAINFO */
  51        GIT_COLOR_CYAN,         /* FRAGINFO */
  52        GIT_COLOR_RED,          /* OLD */
  53        GIT_COLOR_GREEN,        /* NEW */
  54        GIT_COLOR_YELLOW,       /* COMMIT */
  55        GIT_COLOR_BG_RED,       /* WHITESPACE */
  56        GIT_COLOR_NORMAL,       /* FUNCINFO */
  57};
  58
  59static NORETURN void die_want_option(const char *option_name)
  60{
  61        die(_("option '%s' requires a value"), option_name);
  62}
  63
  64static int parse_diff_color_slot(const char *var)
  65{
  66        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  67                return DIFF_CONTEXT;
  68        if (!strcasecmp(var, "meta"))
  69                return DIFF_METAINFO;
  70        if (!strcasecmp(var, "frag"))
  71                return DIFF_FRAGINFO;
  72        if (!strcasecmp(var, "old"))
  73                return DIFF_FILE_OLD;
  74        if (!strcasecmp(var, "new"))
  75                return DIFF_FILE_NEW;
  76        if (!strcasecmp(var, "commit"))
  77                return DIFF_COMMIT;
  78        if (!strcasecmp(var, "whitespace"))
  79                return DIFF_WHITESPACE;
  80        if (!strcasecmp(var, "func"))
  81                return DIFF_FUNCINFO;
  82        return -1;
  83}
  84
  85static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  86                                struct strbuf *errmsg)
  87{
  88        char *params_copy = xstrdup(params_string);
  89        struct string_list params = STRING_LIST_INIT_NODUP;
  90        int ret = 0;
  91        int i;
  92
  93        if (*params_copy)
  94                string_list_split_in_place(&params, params_copy, ',', -1);
  95        for (i = 0; i < params.nr; i++) {
  96                const char *p = params.items[i].string;
  97                if (!strcmp(p, "changes")) {
  98                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  99                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 100                } else if (!strcmp(p, "lines")) {
 101                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
 102                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
 103                } else if (!strcmp(p, "files")) {
 104                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
 105                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
 106                } else if (!strcmp(p, "noncumulative")) {
 107                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 108                } else if (!strcmp(p, "cumulative")) {
 109                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 110                } else if (isdigit(*p)) {
 111                        char *end;
 112                        int permille = strtoul(p, &end, 10) * 10;
 113                        if (*end == '.' && isdigit(*++end)) {
 114                                /* only use first digit */
 115                                permille += *end - '0';
 116                                /* .. and ignore any further digits */
 117                                while (isdigit(*++end))
 118                                        ; /* nothing */
 119                        }
 120                        if (!*end)
 121                                options->dirstat_permille = permille;
 122                        else {
 123                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 124                                            p);
 125                                ret++;
 126                        }
 127                } else {
 128                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 129                        ret++;
 130                }
 131
 132        }
 133        string_list_clear(&params, 0);
 134        free(params_copy);
 135        return ret;
 136}
 137
 138static int parse_submodule_params(struct diff_options *options, const char *value)
 139{
 140        if (!strcmp(value, "log"))
 141                options->submodule_format = DIFF_SUBMODULE_LOG;
 142        else if (!strcmp(value, "short"))
 143                options->submodule_format = DIFF_SUBMODULE_SHORT;
 144        else if (!strcmp(value, "diff"))
 145                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 146        else
 147                return -1;
 148        return 0;
 149}
 150
 151static int git_config_rename(const char *var, const char *value)
 152{
 153        if (!value)
 154                return DIFF_DETECT_RENAME;
 155        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 156                return  DIFF_DETECT_COPY;
 157        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 158}
 159
 160long parse_algorithm_value(const char *value)
 161{
 162        if (!value)
 163                return -1;
 164        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 165                return 0;
 166        else if (!strcasecmp(value, "minimal"))
 167                return XDF_NEED_MINIMAL;
 168        else if (!strcasecmp(value, "patience"))
 169                return XDF_PATIENCE_DIFF;
 170        else if (!strcasecmp(value, "histogram"))
 171                return XDF_HISTOGRAM_DIFF;
 172        return -1;
 173}
 174
 175/*
 176 * These are to give UI layer defaults.
 177 * The core-level commands such as git-diff-files should
 178 * never be affected by the setting of diff.renames
 179 * the user happens to have in the configuration file.
 180 */
 181void init_diff_ui_defaults(void)
 182{
 183        diff_detect_rename_default = 1;
 184}
 185
 186int git_diff_heuristic_config(const char *var, const char *value, void *cb)
 187{
 188        if (!strcmp(var, "diff.indentheuristic")) {
 189                diff_indent_heuristic = git_config_bool(var, value);
 190                if (diff_indent_heuristic)
 191                        diff_compaction_heuristic = 0;
 192        }
 193        if (!strcmp(var, "diff.compactionheuristic")) {
 194                diff_compaction_heuristic = git_config_bool(var, value);
 195                if (diff_compaction_heuristic)
 196                        diff_indent_heuristic = 0;
 197        }
 198        return 0;
 199}
 200
 201int git_diff_ui_config(const char *var, const char *value, void *cb)
 202{
 203        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 204                diff_use_color_default = git_config_colorbool(var, value);
 205                return 0;
 206        }
 207        if (!strcmp(var, "diff.context")) {
 208                diff_context_default = git_config_int(var, value);
 209                if (diff_context_default < 0)
 210                        return -1;
 211                return 0;
 212        }
 213        if (!strcmp(var, "diff.renames")) {
 214                diff_detect_rename_default = git_config_rename(var, value);
 215                return 0;
 216        }
 217        if (!strcmp(var, "diff.autorefreshindex")) {
 218                diff_auto_refresh_index = git_config_bool(var, value);
 219                return 0;
 220        }
 221        if (!strcmp(var, "diff.mnemonicprefix")) {
 222                diff_mnemonic_prefix = git_config_bool(var, value);
 223                return 0;
 224        }
 225        if (!strcmp(var, "diff.noprefix")) {
 226                diff_no_prefix = git_config_bool(var, value);
 227                return 0;
 228        }
 229        if (!strcmp(var, "diff.statgraphwidth")) {
 230                diff_stat_graph_width = git_config_int(var, value);
 231                return 0;
 232        }
 233        if (!strcmp(var, "diff.external"))
 234                return git_config_string(&external_diff_cmd_cfg, var, value);
 235        if (!strcmp(var, "diff.wordregex"))
 236                return git_config_string(&diff_word_regex_cfg, var, value);
 237        if (!strcmp(var, "diff.orderfile"))
 238                return git_config_pathname(&diff_order_file_cfg, var, value);
 239
 240        if (!strcmp(var, "diff.ignoresubmodules"))
 241                handle_ignore_submodules_arg(&default_diff_options, value);
 242
 243        if (!strcmp(var, "diff.submodule")) {
 244                if (parse_submodule_params(&default_diff_options, value))
 245                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 246                                value);
 247                return 0;
 248        }
 249
 250        if (!strcmp(var, "diff.algorithm")) {
 251                diff_algorithm = parse_algorithm_value(value);
 252                if (diff_algorithm < 0)
 253                        return -1;
 254                return 0;
 255        }
 256
 257        if (git_diff_heuristic_config(var, value, cb) < 0)
 258                return -1;
 259        if (git_color_config(var, value, cb) < 0)
 260                return -1;
 261
 262        return git_diff_basic_config(var, value, cb);
 263}
 264
 265int git_diff_basic_config(const char *var, const char *value, void *cb)
 266{
 267        const char *name;
 268
 269        if (!strcmp(var, "diff.renamelimit")) {
 270                diff_rename_limit_default = git_config_int(var, value);
 271                return 0;
 272        }
 273
 274        if (userdiff_config(var, value) < 0)
 275                return -1;
 276
 277        if (skip_prefix(var, "diff.color.", &name) ||
 278            skip_prefix(var, "color.diff.", &name)) {
 279                int slot = parse_diff_color_slot(name);
 280                if (slot < 0)
 281                        return 0;
 282                if (!value)
 283                        return config_error_nonbool(var);
 284                return color_parse(value, diff_colors[slot]);
 285        }
 286
 287        /* like GNU diff's --suppress-blank-empty option  */
 288        if (!strcmp(var, "diff.suppressblankempty") ||
 289                        /* for backwards compatibility */
 290                        !strcmp(var, "diff.suppress-blank-empty")) {
 291                diff_suppress_blank_empty = git_config_bool(var, value);
 292                return 0;
 293        }
 294
 295        if (!strcmp(var, "diff.dirstat")) {
 296                struct strbuf errmsg = STRBUF_INIT;
 297                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 298                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 299                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 300                                errmsg.buf);
 301                strbuf_release(&errmsg);
 302                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 303                return 0;
 304        }
 305
 306        if (starts_with(var, "submodule."))
 307                return parse_submodule_config_option(var, value);
 308
 309        return git_default_config(var, value, cb);
 310}
 311
 312static char *quote_two(const char *one, const char *two)
 313{
 314        int need_one = quote_c_style(one, NULL, NULL, 1);
 315        int need_two = quote_c_style(two, NULL, NULL, 1);
 316        struct strbuf res = STRBUF_INIT;
 317
 318        if (need_one + need_two) {
 319                strbuf_addch(&res, '"');
 320                quote_c_style(one, &res, NULL, 1);
 321                quote_c_style(two, &res, NULL, 1);
 322                strbuf_addch(&res, '"');
 323        } else {
 324                strbuf_addstr(&res, one);
 325                strbuf_addstr(&res, two);
 326        }
 327        return strbuf_detach(&res, NULL);
 328}
 329
 330static const char *external_diff(void)
 331{
 332        static const char *external_diff_cmd = NULL;
 333        static int done_preparing = 0;
 334
 335        if (done_preparing)
 336                return external_diff_cmd;
 337        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 338        if (!external_diff_cmd)
 339                external_diff_cmd = external_diff_cmd_cfg;
 340        done_preparing = 1;
 341        return external_diff_cmd;
 342}
 343
 344/*
 345 * Keep track of files used for diffing. Sometimes such an entry
 346 * refers to a temporary file, sometimes to an existing file, and
 347 * sometimes to "/dev/null".
 348 */
 349static struct diff_tempfile {
 350        /*
 351         * filename external diff should read from, or NULL if this
 352         * entry is currently not in use:
 353         */
 354        const char *name;
 355
 356        char hex[GIT_SHA1_HEXSZ + 1];
 357        char mode[10];
 358
 359        /*
 360         * If this diff_tempfile instance refers to a temporary file,
 361         * this tempfile object is used to manage its lifetime.
 362         */
 363        struct tempfile tempfile;
 364} diff_temp[2];
 365
 366typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 367
 368struct emit_callback {
 369        int color_diff;
 370        unsigned ws_rule;
 371        int blank_at_eof_in_preimage;
 372        int blank_at_eof_in_postimage;
 373        int lno_in_preimage;
 374        int lno_in_postimage;
 375        sane_truncate_fn truncate;
 376        const char **label_path;
 377        struct diff_words_data *diff_words;
 378        struct diff_options *opt;
 379        struct strbuf *header;
 380};
 381
 382static int count_lines(const char *data, int size)
 383{
 384        int count, ch, completely_empty = 1, nl_just_seen = 0;
 385        count = 0;
 386        while (0 < size--) {
 387                ch = *data++;
 388                if (ch == '\n') {
 389                        count++;
 390                        nl_just_seen = 1;
 391                        completely_empty = 0;
 392                }
 393                else {
 394                        nl_just_seen = 0;
 395                        completely_empty = 0;
 396                }
 397        }
 398        if (completely_empty)
 399                return 0;
 400        if (!nl_just_seen)
 401                count++; /* no trailing newline */
 402        return count;
 403}
 404
 405static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 406{
 407        if (!DIFF_FILE_VALID(one)) {
 408                mf->ptr = (char *)""; /* does not matter */
 409                mf->size = 0;
 410                return 0;
 411        }
 412        else if (diff_populate_filespec(one, 0))
 413                return -1;
 414
 415        mf->ptr = one->data;
 416        mf->size = one->size;
 417        return 0;
 418}
 419
 420/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 421static unsigned long diff_filespec_size(struct diff_filespec *one)
 422{
 423        if (!DIFF_FILE_VALID(one))
 424                return 0;
 425        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 426        return one->size;
 427}
 428
 429static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 430{
 431        char *ptr = mf->ptr;
 432        long size = mf->size;
 433        int cnt = 0;
 434
 435        if (!size)
 436                return cnt;
 437        ptr += size - 1; /* pointing at the very end */
 438        if (*ptr != '\n')
 439                ; /* incomplete line */
 440        else
 441                ptr--; /* skip the last LF */
 442        while (mf->ptr < ptr) {
 443                char *prev_eol;
 444                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 445                        if (*prev_eol == '\n')
 446                                break;
 447                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 448                        break;
 449                cnt++;
 450                ptr = prev_eol - 1;
 451        }
 452        return cnt;
 453}
 454
 455static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 456                               struct emit_callback *ecbdata)
 457{
 458        int l1, l2, at;
 459        unsigned ws_rule = ecbdata->ws_rule;
 460        l1 = count_trailing_blank(mf1, ws_rule);
 461        l2 = count_trailing_blank(mf2, ws_rule);
 462        if (l2 <= l1) {
 463                ecbdata->blank_at_eof_in_preimage = 0;
 464                ecbdata->blank_at_eof_in_postimage = 0;
 465                return;
 466        }
 467        at = count_lines(mf1->ptr, mf1->size);
 468        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 469
 470        at = count_lines(mf2->ptr, mf2->size);
 471        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 472}
 473
 474static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 475                        int first, const char *line, int len)
 476{
 477        int has_trailing_newline, has_trailing_carriage_return;
 478        int nofirst;
 479        FILE *file = o->file;
 480
 481        fputs(diff_line_prefix(o), file);
 482
 483        if (len == 0) {
 484                has_trailing_newline = (first == '\n');
 485                has_trailing_carriage_return = (!has_trailing_newline &&
 486                                                (first == '\r'));
 487                nofirst = has_trailing_newline || has_trailing_carriage_return;
 488        } else {
 489                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 490                if (has_trailing_newline)
 491                        len--;
 492                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 493                if (has_trailing_carriage_return)
 494                        len--;
 495                nofirst = 0;
 496        }
 497
 498        if (len || !nofirst) {
 499                fputs(set, file);
 500                if (!nofirst)
 501                        fputc(first, file);
 502                fwrite(line, len, 1, file);
 503                fputs(reset, file);
 504        }
 505        if (has_trailing_carriage_return)
 506                fputc('\r', file);
 507        if (has_trailing_newline)
 508                fputc('\n', file);
 509}
 510
 511static void emit_line(struct diff_options *o, const char *set, const char *reset,
 512                      const char *line, int len)
 513{
 514        emit_line_0(o, set, reset, line[0], line+1, len-1);
 515}
 516
 517static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 518{
 519        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 520              ecbdata->blank_at_eof_in_preimage &&
 521              ecbdata->blank_at_eof_in_postimage &&
 522              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 523              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 524                return 0;
 525        return ws_blank_line(line, len, ecbdata->ws_rule);
 526}
 527
 528static void emit_line_checked(const char *reset,
 529                              struct emit_callback *ecbdata,
 530                              const char *line, int len,
 531                              enum color_diff color,
 532                              unsigned ws_error_highlight,
 533                              char sign)
 534{
 535        const char *set = diff_get_color(ecbdata->color_diff, color);
 536        const char *ws = NULL;
 537
 538        if (ecbdata->opt->ws_error_highlight & ws_error_highlight) {
 539                ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 540                if (!*ws)
 541                        ws = NULL;
 542        }
 543
 544        if (!ws)
 545                emit_line_0(ecbdata->opt, set, reset, sign, line, len);
 546        else if (sign == '+' && new_blank_line_at_eof(ecbdata, line, len))
 547                /* Blank line at EOF - paint '+' as well */
 548                emit_line_0(ecbdata->opt, ws, reset, sign, line, len);
 549        else {
 550                /* Emit just the prefix, then the rest. */
 551                emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
 552                ws_check_emit(line, len, ecbdata->ws_rule,
 553                              ecbdata->opt->file, set, reset, ws);
 554        }
 555}
 556
 557static void emit_add_line(const char *reset,
 558                          struct emit_callback *ecbdata,
 559                          const char *line, int len)
 560{
 561        emit_line_checked(reset, ecbdata, line, len,
 562                          DIFF_FILE_NEW, WSEH_NEW, '+');
 563}
 564
 565static void emit_del_line(const char *reset,
 566                          struct emit_callback *ecbdata,
 567                          const char *line, int len)
 568{
 569        emit_line_checked(reset, ecbdata, line, len,
 570                          DIFF_FILE_OLD, WSEH_OLD, '-');
 571}
 572
 573static void emit_context_line(const char *reset,
 574                              struct emit_callback *ecbdata,
 575                              const char *line, int len)
 576{
 577        emit_line_checked(reset, ecbdata, line, len,
 578                          DIFF_CONTEXT, WSEH_CONTEXT, ' ');
 579}
 580
 581static void emit_hunk_header(struct emit_callback *ecbdata,
 582                             const char *line, int len)
 583{
 584        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 585        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 586        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 587        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 588        static const char atat[2] = { '@', '@' };
 589        const char *cp, *ep;
 590        struct strbuf msgbuf = STRBUF_INIT;
 591        int org_len = len;
 592        int i = 1;
 593
 594        /*
 595         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 596         * it always is at least 10 bytes long.
 597         */
 598        if (len < 10 ||
 599            memcmp(line, atat, 2) ||
 600            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 601                emit_line(ecbdata->opt, context, reset, line, len);
 602                return;
 603        }
 604        ep += 2; /* skip over @@ */
 605
 606        /* The hunk header in fraginfo color */
 607        strbuf_addstr(&msgbuf, frag);
 608        strbuf_add(&msgbuf, line, ep - line);
 609        strbuf_addstr(&msgbuf, reset);
 610
 611        /*
 612         * trailing "\r\n"
 613         */
 614        for ( ; i < 3; i++)
 615                if (line[len - i] == '\r' || line[len - i] == '\n')
 616                        len--;
 617
 618        /* blank before the func header */
 619        for (cp = ep; ep - line < len; ep++)
 620                if (*ep != ' ' && *ep != '\t')
 621                        break;
 622        if (ep != cp) {
 623                strbuf_addstr(&msgbuf, context);
 624                strbuf_add(&msgbuf, cp, ep - cp);
 625                strbuf_addstr(&msgbuf, reset);
 626        }
 627
 628        if (ep < line + len) {
 629                strbuf_addstr(&msgbuf, func);
 630                strbuf_add(&msgbuf, ep, line + len - ep);
 631                strbuf_addstr(&msgbuf, reset);
 632        }
 633
 634        strbuf_add(&msgbuf, line + len, org_len - len);
 635        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 636        strbuf_release(&msgbuf);
 637}
 638
 639static struct diff_tempfile *claim_diff_tempfile(void) {
 640        int i;
 641        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 642                if (!diff_temp[i].name)
 643                        return diff_temp + i;
 644        die("BUG: diff is failing to clean up its tempfiles");
 645}
 646
 647static void remove_tempfile(void)
 648{
 649        int i;
 650        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 651                if (is_tempfile_active(&diff_temp[i].tempfile))
 652                        delete_tempfile(&diff_temp[i].tempfile);
 653                diff_temp[i].name = NULL;
 654        }
 655}
 656
 657static void print_line_count(FILE *file, int count)
 658{
 659        switch (count) {
 660        case 0:
 661                fprintf(file, "0,0");
 662                break;
 663        case 1:
 664                fprintf(file, "1");
 665                break;
 666        default:
 667                fprintf(file, "1,%d", count);
 668                break;
 669        }
 670}
 671
 672static void emit_rewrite_lines(struct emit_callback *ecb,
 673                               int prefix, const char *data, int size)
 674{
 675        const char *endp = NULL;
 676        static const char *nneof = " No newline at end of file\n";
 677        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 678
 679        while (0 < size) {
 680                int len;
 681
 682                endp = memchr(data, '\n', size);
 683                len = endp ? (endp - data + 1) : size;
 684                if (prefix != '+') {
 685                        ecb->lno_in_preimage++;
 686                        emit_del_line(reset, ecb, data, len);
 687                } else {
 688                        ecb->lno_in_postimage++;
 689                        emit_add_line(reset, ecb, data, len);
 690                }
 691                size -= len;
 692                data += len;
 693        }
 694        if (!endp) {
 695                const char *context = diff_get_color(ecb->color_diff,
 696                                                     DIFF_CONTEXT);
 697                putc('\n', ecb->opt->file);
 698                emit_line_0(ecb->opt, context, reset, '\\',
 699                            nneof, strlen(nneof));
 700        }
 701}
 702
 703static void emit_rewrite_diff(const char *name_a,
 704                              const char *name_b,
 705                              struct diff_filespec *one,
 706                              struct diff_filespec *two,
 707                              struct userdiff_driver *textconv_one,
 708                              struct userdiff_driver *textconv_two,
 709                              struct diff_options *o)
 710{
 711        int lc_a, lc_b;
 712        const char *name_a_tab, *name_b_tab;
 713        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 714        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 715        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 716        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 717        const char *a_prefix, *b_prefix;
 718        char *data_one, *data_two;
 719        size_t size_one, size_two;
 720        struct emit_callback ecbdata;
 721        const char *line_prefix = diff_line_prefix(o);
 722
 723        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 724                a_prefix = o->b_prefix;
 725                b_prefix = o->a_prefix;
 726        } else {
 727                a_prefix = o->a_prefix;
 728                b_prefix = o->b_prefix;
 729        }
 730
 731        name_a += (*name_a == '/');
 732        name_b += (*name_b == '/');
 733        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 734        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 735
 736        strbuf_reset(&a_name);
 737        strbuf_reset(&b_name);
 738        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 739        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 740
 741        size_one = fill_textconv(textconv_one, one, &data_one);
 742        size_two = fill_textconv(textconv_two, two, &data_two);
 743
 744        memset(&ecbdata, 0, sizeof(ecbdata));
 745        ecbdata.color_diff = want_color(o->use_color);
 746        ecbdata.ws_rule = whitespace_rule(name_b);
 747        ecbdata.opt = o;
 748        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 749                mmfile_t mf1, mf2;
 750                mf1.ptr = (char *)data_one;
 751                mf2.ptr = (char *)data_two;
 752                mf1.size = size_one;
 753                mf2.size = size_two;
 754                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 755        }
 756        ecbdata.lno_in_preimage = 1;
 757        ecbdata.lno_in_postimage = 1;
 758
 759        lc_a = count_lines(data_one, size_one);
 760        lc_b = count_lines(data_two, size_two);
 761        fprintf(o->file,
 762                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 763                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 764                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 765                line_prefix, fraginfo);
 766        if (!o->irreversible_delete)
 767                print_line_count(o->file, lc_a);
 768        else
 769                fprintf(o->file, "?,?");
 770        fprintf(o->file, " +");
 771        print_line_count(o->file, lc_b);
 772        fprintf(o->file, " @@%s\n", reset);
 773        if (lc_a && !o->irreversible_delete)
 774                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 775        if (lc_b)
 776                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 777        if (textconv_one)
 778                free((char *)data_one);
 779        if (textconv_two)
 780                free((char *)data_two);
 781}
 782
 783struct diff_words_buffer {
 784        mmfile_t text;
 785        long alloc;
 786        struct diff_words_orig {
 787                const char *begin, *end;
 788        } *orig;
 789        int orig_nr, orig_alloc;
 790};
 791
 792static void diff_words_append(char *line, unsigned long len,
 793                struct diff_words_buffer *buffer)
 794{
 795        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 796        line++;
 797        len--;
 798        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 799        buffer->text.size += len;
 800        buffer->text.ptr[buffer->text.size] = '\0';
 801}
 802
 803struct diff_words_style_elem {
 804        const char *prefix;
 805        const char *suffix;
 806        const char *color; /* NULL; filled in by the setup code if
 807                            * color is enabled */
 808};
 809
 810struct diff_words_style {
 811        enum diff_words_type type;
 812        struct diff_words_style_elem new, old, ctx;
 813        const char *newline;
 814};
 815
 816static struct diff_words_style diff_words_styles[] = {
 817        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 818        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 819        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 820};
 821
 822struct diff_words_data {
 823        struct diff_words_buffer minus, plus;
 824        const char *current_plus;
 825        int last_minus;
 826        struct diff_options *opt;
 827        regex_t *word_regex;
 828        enum diff_words_type type;
 829        struct diff_words_style *style;
 830};
 831
 832static int fn_out_diff_words_write_helper(FILE *fp,
 833                                          struct diff_words_style_elem *st_el,
 834                                          const char *newline,
 835                                          size_t count, const char *buf,
 836                                          const char *line_prefix)
 837{
 838        int print = 0;
 839
 840        while (count) {
 841                char *p = memchr(buf, '\n', count);
 842                if (print)
 843                        fputs(line_prefix, fp);
 844                if (p != buf) {
 845                        if (st_el->color && fputs(st_el->color, fp) < 0)
 846                                return -1;
 847                        if (fputs(st_el->prefix, fp) < 0 ||
 848                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 849                            fputs(st_el->suffix, fp) < 0)
 850                                return -1;
 851                        if (st_el->color && *st_el->color
 852                            && fputs(GIT_COLOR_RESET, fp) < 0)
 853                                return -1;
 854                }
 855                if (!p)
 856                        return 0;
 857                if (fputs(newline, fp) < 0)
 858                        return -1;
 859                count -= p + 1 - buf;
 860                buf = p + 1;
 861                print = 1;
 862        }
 863        return 0;
 864}
 865
 866/*
 867 * '--color-words' algorithm can be described as:
 868 *
 869 *   1. collect a the minus/plus lines of a diff hunk, divided into
 870 *      minus-lines and plus-lines;
 871 *
 872 *   2. break both minus-lines and plus-lines into words and
 873 *      place them into two mmfile_t with one word for each line;
 874 *
 875 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 876 *
 877 * And for the common parts of the both file, we output the plus side text.
 878 * diff_words->current_plus is used to trace the current position of the plus file
 879 * which printed. diff_words->last_minus is used to trace the last minus word
 880 * printed.
 881 *
 882 * For '--graph' to work with '--color-words', we need to output the graph prefix
 883 * on each line of color words output. Generally, there are two conditions on
 884 * which we should output the prefix.
 885 *
 886 *   1. diff_words->last_minus == 0 &&
 887 *      diff_words->current_plus == diff_words->plus.text.ptr
 888 *
 889 *      that is: the plus text must start as a new line, and if there is no minus
 890 *      word printed, a graph prefix must be printed.
 891 *
 892 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 893 *      *(diff_words->current_plus - 1) == '\n'
 894 *
 895 *      that is: a graph prefix must be printed following a '\n'
 896 */
 897static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 898{
 899        if ((diff_words->last_minus == 0 &&
 900                diff_words->current_plus == diff_words->plus.text.ptr) ||
 901                (diff_words->current_plus > diff_words->plus.text.ptr &&
 902                *(diff_words->current_plus - 1) == '\n')) {
 903                return 1;
 904        } else {
 905                return 0;
 906        }
 907}
 908
 909static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 910{
 911        struct diff_words_data *diff_words = priv;
 912        struct diff_words_style *style = diff_words->style;
 913        int minus_first, minus_len, plus_first, plus_len;
 914        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 915        struct diff_options *opt = diff_words->opt;
 916        const char *line_prefix;
 917
 918        if (line[0] != '@' || parse_hunk_header(line, len,
 919                        &minus_first, &minus_len, &plus_first, &plus_len))
 920                return;
 921
 922        assert(opt);
 923        line_prefix = diff_line_prefix(opt);
 924
 925        /* POSIX requires that first be decremented by one if len == 0... */
 926        if (minus_len) {
 927                minus_begin = diff_words->minus.orig[minus_first].begin;
 928                minus_end =
 929                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 930        } else
 931                minus_begin = minus_end =
 932                        diff_words->minus.orig[minus_first].end;
 933
 934        if (plus_len) {
 935                plus_begin = diff_words->plus.orig[plus_first].begin;
 936                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 937        } else
 938                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 939
 940        if (color_words_output_graph_prefix(diff_words)) {
 941                fputs(line_prefix, diff_words->opt->file);
 942        }
 943        if (diff_words->current_plus != plus_begin) {
 944                fn_out_diff_words_write_helper(diff_words->opt->file,
 945                                &style->ctx, style->newline,
 946                                plus_begin - diff_words->current_plus,
 947                                diff_words->current_plus, line_prefix);
 948                if (*(plus_begin - 1) == '\n')
 949                        fputs(line_prefix, diff_words->opt->file);
 950        }
 951        if (minus_begin != minus_end) {
 952                fn_out_diff_words_write_helper(diff_words->opt->file,
 953                                &style->old, style->newline,
 954                                minus_end - minus_begin, minus_begin,
 955                                line_prefix);
 956        }
 957        if (plus_begin != plus_end) {
 958                fn_out_diff_words_write_helper(diff_words->opt->file,
 959                                &style->new, style->newline,
 960                                plus_end - plus_begin, plus_begin,
 961                                line_prefix);
 962        }
 963
 964        diff_words->current_plus = plus_end;
 965        diff_words->last_minus = minus_first;
 966}
 967
 968/* This function starts looking at *begin, and returns 0 iff a word was found. */
 969static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 970                int *begin, int *end)
 971{
 972        if (word_regex && *begin < buffer->size) {
 973                regmatch_t match[1];
 974                if (!regexec_buf(word_regex, buffer->ptr + *begin,
 975                                 buffer->size - *begin, 1, match, 0)) {
 976                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 977                                        '\n', match[0].rm_eo - match[0].rm_so);
 978                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 979                        *begin += match[0].rm_so;
 980                        return *begin >= *end;
 981                }
 982                return -1;
 983        }
 984
 985        /* find the next word */
 986        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 987                (*begin)++;
 988        if (*begin >= buffer->size)
 989                return -1;
 990
 991        /* find the end of the word */
 992        *end = *begin + 1;
 993        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 994                (*end)++;
 995
 996        return 0;
 997}
 998
 999/*
1000 * This function splits the words in buffer->text, stores the list with
1001 * newline separator into out, and saves the offsets of the original words
1002 * in buffer->orig.
1003 */
1004static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
1005                regex_t *word_regex)
1006{
1007        int i, j;
1008        long alloc = 0;
1009
1010        out->size = 0;
1011        out->ptr = NULL;
1012
1013        /* fake an empty "0th" word */
1014        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
1015        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
1016        buffer->orig_nr = 1;
1017
1018        for (i = 0; i < buffer->text.size; i++) {
1019                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1020                        return;
1021
1022                /* store original boundaries */
1023                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1024                                buffer->orig_alloc);
1025                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1026                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1027                buffer->orig_nr++;
1028
1029                /* store one word */
1030                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1031                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1032                out->ptr[out->size + j - i] = '\n';
1033                out->size += j - i + 1;
1034
1035                i = j - 1;
1036        }
1037}
1038
1039/* this executes the word diff on the accumulated buffers */
1040static void diff_words_show(struct diff_words_data *diff_words)
1041{
1042        xpparam_t xpp;
1043        xdemitconf_t xecfg;
1044        mmfile_t minus, plus;
1045        struct diff_words_style *style = diff_words->style;
1046
1047        struct diff_options *opt = diff_words->opt;
1048        const char *line_prefix;
1049
1050        assert(opt);
1051        line_prefix = diff_line_prefix(opt);
1052
1053        /* special case: only removal */
1054        if (!diff_words->plus.text.size) {
1055                fputs(line_prefix, diff_words->opt->file);
1056                fn_out_diff_words_write_helper(diff_words->opt->file,
1057                        &style->old, style->newline,
1058                        diff_words->minus.text.size,
1059                        diff_words->minus.text.ptr, line_prefix);
1060                diff_words->minus.text.size = 0;
1061                return;
1062        }
1063
1064        diff_words->current_plus = diff_words->plus.text.ptr;
1065        diff_words->last_minus = 0;
1066
1067        memset(&xpp, 0, sizeof(xpp));
1068        memset(&xecfg, 0, sizeof(xecfg));
1069        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1070        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1071        xpp.flags = 0;
1072        /* as only the hunk header will be parsed, we need a 0-context */
1073        xecfg.ctxlen = 0;
1074        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1075                          &xpp, &xecfg))
1076                die("unable to generate word diff");
1077        free(minus.ptr);
1078        free(plus.ptr);
1079        if (diff_words->current_plus != diff_words->plus.text.ptr +
1080                        diff_words->plus.text.size) {
1081                if (color_words_output_graph_prefix(diff_words))
1082                        fputs(line_prefix, diff_words->opt->file);
1083                fn_out_diff_words_write_helper(diff_words->opt->file,
1084                        &style->ctx, style->newline,
1085                        diff_words->plus.text.ptr + diff_words->plus.text.size
1086                        - diff_words->current_plus, diff_words->current_plus,
1087                        line_prefix);
1088        }
1089        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1090}
1091
1092/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1093static void diff_words_flush(struct emit_callback *ecbdata)
1094{
1095        if (ecbdata->diff_words->minus.text.size ||
1096            ecbdata->diff_words->plus.text.size)
1097                diff_words_show(ecbdata->diff_words);
1098}
1099
1100static void diff_filespec_load_driver(struct diff_filespec *one)
1101{
1102        /* Use already-loaded driver */
1103        if (one->driver)
1104                return;
1105
1106        if (S_ISREG(one->mode))
1107                one->driver = userdiff_find_by_path(one->path);
1108
1109        /* Fallback to default settings */
1110        if (!one->driver)
1111                one->driver = userdiff_find_by_name("default");
1112}
1113
1114static const char *userdiff_word_regex(struct diff_filespec *one)
1115{
1116        diff_filespec_load_driver(one);
1117        return one->driver->word_regex;
1118}
1119
1120static void init_diff_words_data(struct emit_callback *ecbdata,
1121                                 struct diff_options *orig_opts,
1122                                 struct diff_filespec *one,
1123                                 struct diff_filespec *two)
1124{
1125        int i;
1126        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1127        memcpy(o, orig_opts, sizeof(struct diff_options));
1128
1129        ecbdata->diff_words =
1130                xcalloc(1, sizeof(struct diff_words_data));
1131        ecbdata->diff_words->type = o->word_diff;
1132        ecbdata->diff_words->opt = o;
1133        if (!o->word_regex)
1134                o->word_regex = userdiff_word_regex(one);
1135        if (!o->word_regex)
1136                o->word_regex = userdiff_word_regex(two);
1137        if (!o->word_regex)
1138                o->word_regex = diff_word_regex_cfg;
1139        if (o->word_regex) {
1140                ecbdata->diff_words->word_regex = (regex_t *)
1141                        xmalloc(sizeof(regex_t));
1142                if (regcomp(ecbdata->diff_words->word_regex,
1143                            o->word_regex,
1144                            REG_EXTENDED | REG_NEWLINE))
1145                        die ("Invalid regular expression: %s",
1146                             o->word_regex);
1147        }
1148        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1149                if (o->word_diff == diff_words_styles[i].type) {
1150                        ecbdata->diff_words->style =
1151                                &diff_words_styles[i];
1152                        break;
1153                }
1154        }
1155        if (want_color(o->use_color)) {
1156                struct diff_words_style *st = ecbdata->diff_words->style;
1157                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1158                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1159                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1160        }
1161}
1162
1163static void free_diff_words_data(struct emit_callback *ecbdata)
1164{
1165        if (ecbdata->diff_words) {
1166                diff_words_flush(ecbdata);
1167                free (ecbdata->diff_words->opt);
1168                free (ecbdata->diff_words->minus.text.ptr);
1169                free (ecbdata->diff_words->minus.orig);
1170                free (ecbdata->diff_words->plus.text.ptr);
1171                free (ecbdata->diff_words->plus.orig);
1172                if (ecbdata->diff_words->word_regex) {
1173                        regfree(ecbdata->diff_words->word_regex);
1174                        free(ecbdata->diff_words->word_regex);
1175                }
1176                free(ecbdata->diff_words);
1177                ecbdata->diff_words = NULL;
1178        }
1179}
1180
1181const char *diff_get_color(int diff_use_color, enum color_diff ix)
1182{
1183        if (want_color(diff_use_color))
1184                return diff_colors[ix];
1185        return "";
1186}
1187
1188const char *diff_line_prefix(struct diff_options *opt)
1189{
1190        struct strbuf *msgbuf;
1191        if (!opt->output_prefix)
1192                return "";
1193
1194        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1195        return msgbuf->buf;
1196}
1197
1198static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1199{
1200        const char *cp;
1201        unsigned long allot;
1202        size_t l = len;
1203
1204        if (ecb->truncate)
1205                return ecb->truncate(line, len);
1206        cp = line;
1207        allot = l;
1208        while (0 < l) {
1209                (void) utf8_width(&cp, &l);
1210                if (!cp)
1211                        break; /* truncated in the middle? */
1212        }
1213        return allot - l;
1214}
1215
1216static void find_lno(const char *line, struct emit_callback *ecbdata)
1217{
1218        const char *p;
1219        ecbdata->lno_in_preimage = 0;
1220        ecbdata->lno_in_postimage = 0;
1221        p = strchr(line, '-');
1222        if (!p)
1223                return; /* cannot happen */
1224        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1225        p = strchr(p, '+');
1226        if (!p)
1227                return; /* cannot happen */
1228        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1229}
1230
1231static void fn_out_consume(void *priv, char *line, unsigned long len)
1232{
1233        struct emit_callback *ecbdata = priv;
1234        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1235        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1236        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1237        struct diff_options *o = ecbdata->opt;
1238        const char *line_prefix = diff_line_prefix(o);
1239
1240        o->found_changes = 1;
1241
1242        if (ecbdata->header) {
1243                fprintf(o->file, "%s", ecbdata->header->buf);
1244                strbuf_reset(ecbdata->header);
1245                ecbdata->header = NULL;
1246        }
1247
1248        if (ecbdata->label_path[0]) {
1249                const char *name_a_tab, *name_b_tab;
1250
1251                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1252                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1253
1254                fprintf(o->file, "%s%s--- %s%s%s\n",
1255                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1256                fprintf(o->file, "%s%s+++ %s%s%s\n",
1257                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1258                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1259        }
1260
1261        if (diff_suppress_blank_empty
1262            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1263                line[0] = '\n';
1264                len = 1;
1265        }
1266
1267        if (line[0] == '@') {
1268                if (ecbdata->diff_words)
1269                        diff_words_flush(ecbdata);
1270                len = sane_truncate_line(ecbdata, line, len);
1271                find_lno(line, ecbdata);
1272                emit_hunk_header(ecbdata, line, len);
1273                if (line[len-1] != '\n')
1274                        putc('\n', o->file);
1275                return;
1276        }
1277
1278        if (ecbdata->diff_words) {
1279                if (line[0] == '-') {
1280                        diff_words_append(line, len,
1281                                          &ecbdata->diff_words->minus);
1282                        return;
1283                } else if (line[0] == '+') {
1284                        diff_words_append(line, len,
1285                                          &ecbdata->diff_words->plus);
1286                        return;
1287                } else if (starts_with(line, "\\ ")) {
1288                        /*
1289                         * Eat the "no newline at eof" marker as if we
1290                         * saw a "+" or "-" line with nothing on it,
1291                         * and return without diff_words_flush() to
1292                         * defer processing. If this is the end of
1293                         * preimage, more "+" lines may come after it.
1294                         */
1295                        return;
1296                }
1297                diff_words_flush(ecbdata);
1298                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1299                        emit_line(o, context, reset, line, len);
1300                        fputs("~\n", o->file);
1301                } else {
1302                        /*
1303                         * Skip the prefix character, if any.  With
1304                         * diff_suppress_blank_empty, there may be
1305                         * none.
1306                         */
1307                        if (line[0] != '\n') {
1308                              line++;
1309                              len--;
1310                        }
1311                        emit_line(o, context, reset, line, len);
1312                }
1313                return;
1314        }
1315
1316        switch (line[0]) {
1317        case '+':
1318                ecbdata->lno_in_postimage++;
1319                emit_add_line(reset, ecbdata, line + 1, len - 1);
1320                break;
1321        case '-':
1322                ecbdata->lno_in_preimage++;
1323                emit_del_line(reset, ecbdata, line + 1, len - 1);
1324                break;
1325        case ' ':
1326                ecbdata->lno_in_postimage++;
1327                ecbdata->lno_in_preimage++;
1328                emit_context_line(reset, ecbdata, line + 1, len - 1);
1329                break;
1330        default:
1331                /* incomplete line at the end */
1332                ecbdata->lno_in_preimage++;
1333                emit_line(o, diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
1334                          reset, line, len);
1335                break;
1336        }
1337}
1338
1339static char *pprint_rename(const char *a, const char *b)
1340{
1341        const char *old = a;
1342        const char *new = b;
1343        struct strbuf name = STRBUF_INIT;
1344        int pfx_length, sfx_length;
1345        int pfx_adjust_for_slash;
1346        int len_a = strlen(a);
1347        int len_b = strlen(b);
1348        int a_midlen, b_midlen;
1349        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1350        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1351
1352        if (qlen_a || qlen_b) {
1353                quote_c_style(a, &name, NULL, 0);
1354                strbuf_addstr(&name, " => ");
1355                quote_c_style(b, &name, NULL, 0);
1356                return strbuf_detach(&name, NULL);
1357        }
1358
1359        /* Find common prefix */
1360        pfx_length = 0;
1361        while (*old && *new && *old == *new) {
1362                if (*old == '/')
1363                        pfx_length = old - a + 1;
1364                old++;
1365                new++;
1366        }
1367
1368        /* Find common suffix */
1369        old = a + len_a;
1370        new = b + len_b;
1371        sfx_length = 0;
1372        /*
1373         * If there is a common prefix, it must end in a slash.  In
1374         * that case we let this loop run 1 into the prefix to see the
1375         * same slash.
1376         *
1377         * If there is no common prefix, we cannot do this as it would
1378         * underrun the input strings.
1379         */
1380        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1381        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1382               b + pfx_length - pfx_adjust_for_slash <= new &&
1383               *old == *new) {
1384                if (*old == '/')
1385                        sfx_length = len_a - (old - a);
1386                old--;
1387                new--;
1388        }
1389
1390        /*
1391         * pfx{mid-a => mid-b}sfx
1392         * {pfx-a => pfx-b}sfx
1393         * pfx{sfx-a => sfx-b}
1394         * name-a => name-b
1395         */
1396        a_midlen = len_a - pfx_length - sfx_length;
1397        b_midlen = len_b - pfx_length - sfx_length;
1398        if (a_midlen < 0)
1399                a_midlen = 0;
1400        if (b_midlen < 0)
1401                b_midlen = 0;
1402
1403        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1404        if (pfx_length + sfx_length) {
1405                strbuf_add(&name, a, pfx_length);
1406                strbuf_addch(&name, '{');
1407        }
1408        strbuf_add(&name, a + pfx_length, a_midlen);
1409        strbuf_addstr(&name, " => ");
1410        strbuf_add(&name, b + pfx_length, b_midlen);
1411        if (pfx_length + sfx_length) {
1412                strbuf_addch(&name, '}');
1413                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1414        }
1415        return strbuf_detach(&name, NULL);
1416}
1417
1418struct diffstat_t {
1419        int nr;
1420        int alloc;
1421        struct diffstat_file {
1422                char *from_name;
1423                char *name;
1424                char *print_name;
1425                unsigned is_unmerged:1;
1426                unsigned is_binary:1;
1427                unsigned is_renamed:1;
1428                unsigned is_interesting:1;
1429                uintmax_t added, deleted;
1430        } **files;
1431};
1432
1433static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1434                                          const char *name_a,
1435                                          const char *name_b)
1436{
1437        struct diffstat_file *x;
1438        x = xcalloc(1, sizeof(*x));
1439        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1440        diffstat->files[diffstat->nr++] = x;
1441        if (name_b) {
1442                x->from_name = xstrdup(name_a);
1443                x->name = xstrdup(name_b);
1444                x->is_renamed = 1;
1445        }
1446        else {
1447                x->from_name = NULL;
1448                x->name = xstrdup(name_a);
1449        }
1450        return x;
1451}
1452
1453static void diffstat_consume(void *priv, char *line, unsigned long len)
1454{
1455        struct diffstat_t *diffstat = priv;
1456        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1457
1458        if (line[0] == '+')
1459                x->added++;
1460        else if (line[0] == '-')
1461                x->deleted++;
1462}
1463
1464const char mime_boundary_leader[] = "------------";
1465
1466static int scale_linear(int it, int width, int max_change)
1467{
1468        if (!it)
1469                return 0;
1470        /*
1471         * make sure that at least one '-' or '+' is printed if
1472         * there is any change to this path. The easiest way is to
1473         * scale linearly as if the alloted width is one column shorter
1474         * than it is, and then add 1 to the result.
1475         */
1476        return 1 + (it * (width - 1) / max_change);
1477}
1478
1479static void show_name(FILE *file,
1480                      const char *prefix, const char *name, int len)
1481{
1482        fprintf(file, " %s%-*s |", prefix, len, name);
1483}
1484
1485static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1486{
1487        if (cnt <= 0)
1488                return;
1489        fprintf(file, "%s", set);
1490        while (cnt--)
1491                putc(ch, file);
1492        fprintf(file, "%s", reset);
1493}
1494
1495static void fill_print_name(struct diffstat_file *file)
1496{
1497        char *pname;
1498
1499        if (file->print_name)
1500                return;
1501
1502        if (!file->is_renamed) {
1503                struct strbuf buf = STRBUF_INIT;
1504                if (quote_c_style(file->name, &buf, NULL, 0)) {
1505                        pname = strbuf_detach(&buf, NULL);
1506                } else {
1507                        pname = file->name;
1508                        strbuf_release(&buf);
1509                }
1510        } else {
1511                pname = pprint_rename(file->from_name, file->name);
1512        }
1513        file->print_name = pname;
1514}
1515
1516int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1517{
1518        struct strbuf sb = STRBUF_INIT;
1519        int ret;
1520
1521        if (!files) {
1522                assert(insertions == 0 && deletions == 0);
1523                return fprintf(fp, "%s\n", " 0 files changed");
1524        }
1525
1526        strbuf_addf(&sb,
1527                    (files == 1) ? " %d file changed" : " %d files changed",
1528                    files);
1529
1530        /*
1531         * For binary diff, the caller may want to print "x files
1532         * changed" with insertions == 0 && deletions == 0.
1533         *
1534         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1535         * is probably less confusing (i.e skip over "2 files changed
1536         * but nothing about added/removed lines? Is this a bug in Git?").
1537         */
1538        if (insertions || deletions == 0) {
1539                strbuf_addf(&sb,
1540                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1541                            insertions);
1542        }
1543
1544        if (deletions || insertions == 0) {
1545                strbuf_addf(&sb,
1546                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1547                            deletions);
1548        }
1549        strbuf_addch(&sb, '\n');
1550        ret = fputs(sb.buf, fp);
1551        strbuf_release(&sb);
1552        return ret;
1553}
1554
1555static void show_stats(struct diffstat_t *data, struct diff_options *options)
1556{
1557        int i, len, add, del, adds = 0, dels = 0;
1558        uintmax_t max_change = 0, max_len = 0;
1559        int total_files = data->nr, count;
1560        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1561        const char *reset, *add_c, *del_c;
1562        const char *line_prefix = "";
1563        int extra_shown = 0;
1564
1565        if (data->nr == 0)
1566                return;
1567
1568        line_prefix = diff_line_prefix(options);
1569        count = options->stat_count ? options->stat_count : data->nr;
1570
1571        reset = diff_get_color_opt(options, DIFF_RESET);
1572        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1573        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1574
1575        /*
1576         * Find the longest filename and max number of changes
1577         */
1578        for (i = 0; (i < count) && (i < data->nr); i++) {
1579                struct diffstat_file *file = data->files[i];
1580                uintmax_t change = file->added + file->deleted;
1581
1582                if (!file->is_interesting && (change == 0)) {
1583                        count++; /* not shown == room for one more */
1584                        continue;
1585                }
1586                fill_print_name(file);
1587                len = strlen(file->print_name);
1588                if (max_len < len)
1589                        max_len = len;
1590
1591                if (file->is_unmerged) {
1592                        /* "Unmerged" is 8 characters */
1593                        bin_width = bin_width < 8 ? 8 : bin_width;
1594                        continue;
1595                }
1596                if (file->is_binary) {
1597                        /* "Bin XXX -> YYY bytes" */
1598                        int w = 14 + decimal_width(file->added)
1599                                + decimal_width(file->deleted);
1600                        bin_width = bin_width < w ? w : bin_width;
1601                        /* Display change counts aligned with "Bin" */
1602                        number_width = 3;
1603                        continue;
1604                }
1605
1606                if (max_change < change)
1607                        max_change = change;
1608        }
1609        count = i; /* where we can stop scanning in data->files[] */
1610
1611        /*
1612         * We have width = stat_width or term_columns() columns total.
1613         * We want a maximum of min(max_len, stat_name_width) for the name part.
1614         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1615         * We also need 1 for " " and 4 + decimal_width(max_change)
1616         * for " | NNNN " and one the empty column at the end, altogether
1617         * 6 + decimal_width(max_change).
1618         *
1619         * If there's not enough space, we will use the smaller of
1620         * stat_name_width (if set) and 5/8*width for the filename,
1621         * and the rest for constant elements + graph part, but no more
1622         * than stat_graph_width for the graph part.
1623         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1624         * for the standard terminal size).
1625         *
1626         * In other words: stat_width limits the maximum width, and
1627         * stat_name_width fixes the maximum width of the filename,
1628         * and is also used to divide available columns if there
1629         * aren't enough.
1630         *
1631         * Binary files are displayed with "Bin XXX -> YYY bytes"
1632         * instead of the change count and graph. This part is treated
1633         * similarly to the graph part, except that it is not
1634         * "scaled". If total width is too small to accommodate the
1635         * guaranteed minimum width of the filename part and the
1636         * separators and this message, this message will "overflow"
1637         * making the line longer than the maximum width.
1638         */
1639
1640        if (options->stat_width == -1)
1641                width = term_columns() - strlen(line_prefix);
1642        else
1643                width = options->stat_width ? options->stat_width : 80;
1644        number_width = decimal_width(max_change) > number_width ?
1645                decimal_width(max_change) : number_width;
1646
1647        if (options->stat_graph_width == -1)
1648                options->stat_graph_width = diff_stat_graph_width;
1649
1650        /*
1651         * Guarantee 3/8*16==6 for the graph part
1652         * and 5/8*16==10 for the filename part
1653         */
1654        if (width < 16 + 6 + number_width)
1655                width = 16 + 6 + number_width;
1656
1657        /*
1658         * First assign sizes that are wanted, ignoring available width.
1659         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1660         * starting from "XXX" should fit in graph_width.
1661         */
1662        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1663        if (options->stat_graph_width &&
1664            options->stat_graph_width < graph_width)
1665                graph_width = options->stat_graph_width;
1666
1667        name_width = (options->stat_name_width > 0 &&
1668                      options->stat_name_width < max_len) ?
1669                options->stat_name_width : max_len;
1670
1671        /*
1672         * Adjust adjustable widths not to exceed maximum width
1673         */
1674        if (name_width + number_width + 6 + graph_width > width) {
1675                if (graph_width > width * 3/8 - number_width - 6) {
1676                        graph_width = width * 3/8 - number_width - 6;
1677                        if (graph_width < 6)
1678                                graph_width = 6;
1679                }
1680
1681                if (options->stat_graph_width &&
1682                    graph_width > options->stat_graph_width)
1683                        graph_width = options->stat_graph_width;
1684                if (name_width > width - number_width - 6 - graph_width)
1685                        name_width = width - number_width - 6 - graph_width;
1686                else
1687                        graph_width = width - number_width - 6 - name_width;
1688        }
1689
1690        /*
1691         * From here name_width is the width of the name area,
1692         * and graph_width is the width of the graph area.
1693         * max_change is used to scale graph properly.
1694         */
1695        for (i = 0; i < count; i++) {
1696                const char *prefix = "";
1697                struct diffstat_file *file = data->files[i];
1698                char *name = file->print_name;
1699                uintmax_t added = file->added;
1700                uintmax_t deleted = file->deleted;
1701                int name_len;
1702
1703                if (!file->is_interesting && (added + deleted == 0))
1704                        continue;
1705
1706                /*
1707                 * "scale" the filename
1708                 */
1709                len = name_width;
1710                name_len = strlen(name);
1711                if (name_width < name_len) {
1712                        char *slash;
1713                        prefix = "...";
1714                        len -= 3;
1715                        name += name_len - len;
1716                        slash = strchr(name, '/');
1717                        if (slash)
1718                                name = slash;
1719                }
1720
1721                if (file->is_binary) {
1722                        fprintf(options->file, "%s", line_prefix);
1723                        show_name(options->file, prefix, name, len);
1724                        fprintf(options->file, " %*s", number_width, "Bin");
1725                        if (!added && !deleted) {
1726                                putc('\n', options->file);
1727                                continue;
1728                        }
1729                        fprintf(options->file, " %s%"PRIuMAX"%s",
1730                                del_c, deleted, reset);
1731                        fprintf(options->file, " -> ");
1732                        fprintf(options->file, "%s%"PRIuMAX"%s",
1733                                add_c, added, reset);
1734                        fprintf(options->file, " bytes");
1735                        fprintf(options->file, "\n");
1736                        continue;
1737                }
1738                else if (file->is_unmerged) {
1739                        fprintf(options->file, "%s", line_prefix);
1740                        show_name(options->file, prefix, name, len);
1741                        fprintf(options->file, " Unmerged\n");
1742                        continue;
1743                }
1744
1745                /*
1746                 * scale the add/delete
1747                 */
1748                add = added;
1749                del = deleted;
1750
1751                if (graph_width <= max_change) {
1752                        int total = scale_linear(add + del, graph_width, max_change);
1753                        if (total < 2 && add && del)
1754                                /* width >= 2 due to the sanity check */
1755                                total = 2;
1756                        if (add < del) {
1757                                add = scale_linear(add, graph_width, max_change);
1758                                del = total - add;
1759                        } else {
1760                                del = scale_linear(del, graph_width, max_change);
1761                                add = total - del;
1762                        }
1763                }
1764                fprintf(options->file, "%s", line_prefix);
1765                show_name(options->file, prefix, name, len);
1766                fprintf(options->file, " %*"PRIuMAX"%s",
1767                        number_width, added + deleted,
1768                        added + deleted ? " " : "");
1769                show_graph(options->file, '+', add, add_c, reset);
1770                show_graph(options->file, '-', del, del_c, reset);
1771                fprintf(options->file, "\n");
1772        }
1773
1774        for (i = 0; i < data->nr; i++) {
1775                struct diffstat_file *file = data->files[i];
1776                uintmax_t added = file->added;
1777                uintmax_t deleted = file->deleted;
1778
1779                if (file->is_unmerged ||
1780                    (!file->is_interesting && (added + deleted == 0))) {
1781                        total_files--;
1782                        continue;
1783                }
1784
1785                if (!file->is_binary) {
1786                        adds += added;
1787                        dels += deleted;
1788                }
1789                if (i < count)
1790                        continue;
1791                if (!extra_shown)
1792                        fprintf(options->file, "%s ...\n", line_prefix);
1793                extra_shown = 1;
1794        }
1795        fprintf(options->file, "%s", line_prefix);
1796        print_stat_summary(options->file, total_files, adds, dels);
1797}
1798
1799static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1800{
1801        int i, adds = 0, dels = 0, total_files = data->nr;
1802
1803        if (data->nr == 0)
1804                return;
1805
1806        for (i = 0; i < data->nr; i++) {
1807                int added = data->files[i]->added;
1808                int deleted= data->files[i]->deleted;
1809
1810                if (data->files[i]->is_unmerged ||
1811                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1812                        total_files--;
1813                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1814                        adds += added;
1815                        dels += deleted;
1816                }
1817        }
1818        fprintf(options->file, "%s", diff_line_prefix(options));
1819        print_stat_summary(options->file, total_files, adds, dels);
1820}
1821
1822static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1823{
1824        int i;
1825
1826        if (data->nr == 0)
1827                return;
1828
1829        for (i = 0; i < data->nr; i++) {
1830                struct diffstat_file *file = data->files[i];
1831
1832                fprintf(options->file, "%s", diff_line_prefix(options));
1833
1834                if (file->is_binary)
1835                        fprintf(options->file, "-\t-\t");
1836                else
1837                        fprintf(options->file,
1838                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1839                                file->added, file->deleted);
1840                if (options->line_termination) {
1841                        fill_print_name(file);
1842                        if (!file->is_renamed)
1843                                write_name_quoted(file->name, options->file,
1844                                                  options->line_termination);
1845                        else {
1846                                fputs(file->print_name, options->file);
1847                                putc(options->line_termination, options->file);
1848                        }
1849                } else {
1850                        if (file->is_renamed) {
1851                                putc('\0', options->file);
1852                                write_name_quoted(file->from_name, options->file, '\0');
1853                        }
1854                        write_name_quoted(file->name, options->file, '\0');
1855                }
1856        }
1857}
1858
1859struct dirstat_file {
1860        const char *name;
1861        unsigned long changed;
1862};
1863
1864struct dirstat_dir {
1865        struct dirstat_file *files;
1866        int alloc, nr, permille, cumulative;
1867};
1868
1869static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1870                unsigned long changed, const char *base, int baselen)
1871{
1872        unsigned long this_dir = 0;
1873        unsigned int sources = 0;
1874        const char *line_prefix = diff_line_prefix(opt);
1875
1876        while (dir->nr) {
1877                struct dirstat_file *f = dir->files;
1878                int namelen = strlen(f->name);
1879                unsigned long this;
1880                char *slash;
1881
1882                if (namelen < baselen)
1883                        break;
1884                if (memcmp(f->name, base, baselen))
1885                        break;
1886                slash = strchr(f->name + baselen, '/');
1887                if (slash) {
1888                        int newbaselen = slash + 1 - f->name;
1889                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1890                        sources++;
1891                } else {
1892                        this = f->changed;
1893                        dir->files++;
1894                        dir->nr--;
1895                        sources += 2;
1896                }
1897                this_dir += this;
1898        }
1899
1900        /*
1901         * We don't report dirstat's for
1902         *  - the top level
1903         *  - or cases where everything came from a single directory
1904         *    under this directory (sources == 1).
1905         */
1906        if (baselen && sources != 1) {
1907                if (this_dir) {
1908                        int permille = this_dir * 1000 / changed;
1909                        if (permille >= dir->permille) {
1910                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1911                                        permille / 10, permille % 10, baselen, base);
1912                                if (!dir->cumulative)
1913                                        return 0;
1914                        }
1915                }
1916        }
1917        return this_dir;
1918}
1919
1920static int dirstat_compare(const void *_a, const void *_b)
1921{
1922        const struct dirstat_file *a = _a;
1923        const struct dirstat_file *b = _b;
1924        return strcmp(a->name, b->name);
1925}
1926
1927static void show_dirstat(struct diff_options *options)
1928{
1929        int i;
1930        unsigned long changed;
1931        struct dirstat_dir dir;
1932        struct diff_queue_struct *q = &diff_queued_diff;
1933
1934        dir.files = NULL;
1935        dir.alloc = 0;
1936        dir.nr = 0;
1937        dir.permille = options->dirstat_permille;
1938        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1939
1940        changed = 0;
1941        for (i = 0; i < q->nr; i++) {
1942                struct diff_filepair *p = q->queue[i];
1943                const char *name;
1944                unsigned long copied, added, damage;
1945                int content_changed;
1946
1947                name = p->two->path ? p->two->path : p->one->path;
1948
1949                if (p->one->oid_valid && p->two->oid_valid)
1950                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
1951                else
1952                        content_changed = 1;
1953
1954                if (!content_changed) {
1955                        /*
1956                         * The SHA1 has not changed, so pre-/post-content is
1957                         * identical. We can therefore skip looking at the
1958                         * file contents altogether.
1959                         */
1960                        damage = 0;
1961                        goto found_damage;
1962                }
1963
1964                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1965                        /*
1966                         * In --dirstat-by-file mode, we don't really need to
1967                         * look at the actual file contents at all.
1968                         * The fact that the SHA1 changed is enough for us to
1969                         * add this file to the list of results
1970                         * (with each file contributing equal damage).
1971                         */
1972                        damage = 1;
1973                        goto found_damage;
1974                }
1975
1976                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1977                        diff_populate_filespec(p->one, 0);
1978                        diff_populate_filespec(p->two, 0);
1979                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1980                                               &copied, &added);
1981                        diff_free_filespec_data(p->one);
1982                        diff_free_filespec_data(p->two);
1983                } else if (DIFF_FILE_VALID(p->one)) {
1984                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
1985                        copied = added = 0;
1986                        diff_free_filespec_data(p->one);
1987                } else if (DIFF_FILE_VALID(p->two)) {
1988                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
1989                        copied = 0;
1990                        added = p->two->size;
1991                        diff_free_filespec_data(p->two);
1992                } else
1993                        continue;
1994
1995                /*
1996                 * Original minus copied is the removed material,
1997                 * added is the new material.  They are both damages
1998                 * made to the preimage.
1999                 * If the resulting damage is zero, we know that
2000                 * diffcore_count_changes() considers the two entries to
2001                 * be identical, but since content_changed is true, we
2002                 * know that there must have been _some_ kind of change,
2003                 * so we force all entries to have damage > 0.
2004                 */
2005                damage = (p->one->size - copied) + added;
2006                if (!damage)
2007                        damage = 1;
2008
2009found_damage:
2010                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2011                dir.files[dir.nr].name = name;
2012                dir.files[dir.nr].changed = damage;
2013                changed += damage;
2014                dir.nr++;
2015        }
2016
2017        /* This can happen even with many files, if everything was renames */
2018        if (!changed)
2019                return;
2020
2021        /* Show all directories with more than x% of the changes */
2022        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2023        gather_dirstat(options, &dir, changed, "", 0);
2024}
2025
2026static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2027{
2028        int i;
2029        unsigned long changed;
2030        struct dirstat_dir dir;
2031
2032        if (data->nr == 0)
2033                return;
2034
2035        dir.files = NULL;
2036        dir.alloc = 0;
2037        dir.nr = 0;
2038        dir.permille = options->dirstat_permille;
2039        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2040
2041        changed = 0;
2042        for (i = 0; i < data->nr; i++) {
2043                struct diffstat_file *file = data->files[i];
2044                unsigned long damage = file->added + file->deleted;
2045                if (file->is_binary)
2046                        /*
2047                         * binary files counts bytes, not lines. Must find some
2048                         * way to normalize binary bytes vs. textual lines.
2049                         * The following heuristic assumes that there are 64
2050                         * bytes per "line".
2051                         * This is stupid and ugly, but very cheap...
2052                         */
2053                        damage = (damage + 63) / 64;
2054                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2055                dir.files[dir.nr].name = file->name;
2056                dir.files[dir.nr].changed = damage;
2057                changed += damage;
2058                dir.nr++;
2059        }
2060
2061        /* This can happen even with many files, if everything was renames */
2062        if (!changed)
2063                return;
2064
2065        /* Show all directories with more than x% of the changes */
2066        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2067        gather_dirstat(options, &dir, changed, "", 0);
2068}
2069
2070static void free_diffstat_info(struct diffstat_t *diffstat)
2071{
2072        int i;
2073        for (i = 0; i < diffstat->nr; i++) {
2074                struct diffstat_file *f = diffstat->files[i];
2075                if (f->name != f->print_name)
2076                        free(f->print_name);
2077                free(f->name);
2078                free(f->from_name);
2079                free(f);
2080        }
2081        free(diffstat->files);
2082}
2083
2084struct checkdiff_t {
2085        const char *filename;
2086        int lineno;
2087        int conflict_marker_size;
2088        struct diff_options *o;
2089        unsigned ws_rule;
2090        unsigned status;
2091};
2092
2093static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2094{
2095        char firstchar;
2096        int cnt;
2097
2098        if (len < marker_size + 1)
2099                return 0;
2100        firstchar = line[0];
2101        switch (firstchar) {
2102        case '=': case '>': case '<': case '|':
2103                break;
2104        default:
2105                return 0;
2106        }
2107        for (cnt = 1; cnt < marker_size; cnt++)
2108                if (line[cnt] != firstchar)
2109                        return 0;
2110        /* line[1] thru line[marker_size-1] are same as firstchar */
2111        if (len < marker_size + 1 || !isspace(line[marker_size]))
2112                return 0;
2113        return 1;
2114}
2115
2116static void checkdiff_consume(void *priv, char *line, unsigned long len)
2117{
2118        struct checkdiff_t *data = priv;
2119        int marker_size = data->conflict_marker_size;
2120        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2121        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2122        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2123        char *err;
2124        const char *line_prefix;
2125
2126        assert(data->o);
2127        line_prefix = diff_line_prefix(data->o);
2128
2129        if (line[0] == '+') {
2130                unsigned bad;
2131                data->lineno++;
2132                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2133                        data->status |= 1;
2134                        fprintf(data->o->file,
2135                                "%s%s:%d: leftover conflict marker\n",
2136                                line_prefix, data->filename, data->lineno);
2137                }
2138                bad = ws_check(line + 1, len - 1, data->ws_rule);
2139                if (!bad)
2140                        return;
2141                data->status |= bad;
2142                err = whitespace_error_string(bad);
2143                fprintf(data->o->file, "%s%s:%d: %s.\n",
2144                        line_prefix, data->filename, data->lineno, err);
2145                free(err);
2146                emit_line(data->o, set, reset, line, 1);
2147                ws_check_emit(line + 1, len - 1, data->ws_rule,
2148                              data->o->file, set, reset, ws);
2149        } else if (line[0] == ' ') {
2150                data->lineno++;
2151        } else if (line[0] == '@') {
2152                char *plus = strchr(line, '+');
2153                if (plus)
2154                        data->lineno = strtol(plus, NULL, 10) - 1;
2155                else
2156                        die("invalid diff");
2157        }
2158}
2159
2160static unsigned char *deflate_it(char *data,
2161                                 unsigned long size,
2162                                 unsigned long *result_size)
2163{
2164        int bound;
2165        unsigned char *deflated;
2166        git_zstream stream;
2167
2168        git_deflate_init(&stream, zlib_compression_level);
2169        bound = git_deflate_bound(&stream, size);
2170        deflated = xmalloc(bound);
2171        stream.next_out = deflated;
2172        stream.avail_out = bound;
2173
2174        stream.next_in = (unsigned char *)data;
2175        stream.avail_in = size;
2176        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2177                ; /* nothing */
2178        git_deflate_end(&stream);
2179        *result_size = stream.total_out;
2180        return deflated;
2181}
2182
2183static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2184                                  const char *prefix)
2185{
2186        void *cp;
2187        void *delta;
2188        void *deflated;
2189        void *data;
2190        unsigned long orig_size;
2191        unsigned long delta_size;
2192        unsigned long deflate_size;
2193        unsigned long data_size;
2194
2195        /* We could do deflated delta, or we could do just deflated two,
2196         * whichever is smaller.
2197         */
2198        delta = NULL;
2199        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2200        if (one->size && two->size) {
2201                delta = diff_delta(one->ptr, one->size,
2202                                   two->ptr, two->size,
2203                                   &delta_size, deflate_size);
2204                if (delta) {
2205                        void *to_free = delta;
2206                        orig_size = delta_size;
2207                        delta = deflate_it(delta, delta_size, &delta_size);
2208                        free(to_free);
2209                }
2210        }
2211
2212        if (delta && delta_size < deflate_size) {
2213                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2214                free(deflated);
2215                data = delta;
2216                data_size = delta_size;
2217        }
2218        else {
2219                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2220                free(delta);
2221                data = deflated;
2222                data_size = deflate_size;
2223        }
2224
2225        /* emit data encoded in base85 */
2226        cp = data;
2227        while (data_size) {
2228                int bytes = (52 < data_size) ? 52 : data_size;
2229                char line[70];
2230                data_size -= bytes;
2231                if (bytes <= 26)
2232                        line[0] = bytes + 'A' - 1;
2233                else
2234                        line[0] = bytes - 26 + 'a' - 1;
2235                encode_85(line + 1, cp, bytes);
2236                cp = (char *) cp + bytes;
2237                fprintf(file, "%s", prefix);
2238                fputs(line, file);
2239                fputc('\n', file);
2240        }
2241        fprintf(file, "%s\n", prefix);
2242        free(data);
2243}
2244
2245static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2246                             const char *prefix)
2247{
2248        fprintf(file, "%sGIT binary patch\n", prefix);
2249        emit_binary_diff_body(file, one, two, prefix);
2250        emit_binary_diff_body(file, two, one, prefix);
2251}
2252
2253int diff_filespec_is_binary(struct diff_filespec *one)
2254{
2255        if (one->is_binary == -1) {
2256                diff_filespec_load_driver(one);
2257                if (one->driver->binary != -1)
2258                        one->is_binary = one->driver->binary;
2259                else {
2260                        if (!one->data && DIFF_FILE_VALID(one))
2261                                diff_populate_filespec(one, CHECK_BINARY);
2262                        if (one->is_binary == -1 && one->data)
2263                                one->is_binary = buffer_is_binary(one->data,
2264                                                one->size);
2265                        if (one->is_binary == -1)
2266                                one->is_binary = 0;
2267                }
2268        }
2269        return one->is_binary;
2270}
2271
2272static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2273{
2274        diff_filespec_load_driver(one);
2275        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2276}
2277
2278void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2279{
2280        if (!options->a_prefix)
2281                options->a_prefix = a;
2282        if (!options->b_prefix)
2283                options->b_prefix = b;
2284}
2285
2286struct userdiff_driver *get_textconv(struct diff_filespec *one)
2287{
2288        if (!DIFF_FILE_VALID(one))
2289                return NULL;
2290
2291        diff_filespec_load_driver(one);
2292        return userdiff_get_textconv(one->driver);
2293}
2294
2295static void builtin_diff(const char *name_a,
2296                         const char *name_b,
2297                         struct diff_filespec *one,
2298                         struct diff_filespec *two,
2299                         const char *xfrm_msg,
2300                         int must_show_header,
2301                         struct diff_options *o,
2302                         int complete_rewrite)
2303{
2304        mmfile_t mf1, mf2;
2305        const char *lbl[2];
2306        char *a_one, *b_two;
2307        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2308        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2309        const char *a_prefix, *b_prefix;
2310        struct userdiff_driver *textconv_one = NULL;
2311        struct userdiff_driver *textconv_two = NULL;
2312        struct strbuf header = STRBUF_INIT;
2313        const char *line_prefix = diff_line_prefix(o);
2314
2315        diff_set_mnemonic_prefix(o, "a/", "b/");
2316        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2317                a_prefix = o->b_prefix;
2318                b_prefix = o->a_prefix;
2319        } else {
2320                a_prefix = o->a_prefix;
2321                b_prefix = o->b_prefix;
2322        }
2323
2324        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
2325            (!one->mode || S_ISGITLINK(one->mode)) &&
2326            (!two->mode || S_ISGITLINK(two->mode))) {
2327                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2328                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2329                show_submodule_summary(o->file, one->path ? one->path : two->path,
2330                                line_prefix,
2331                                &one->oid, &two->oid,
2332                                two->dirty_submodule,
2333                                meta, del, add, reset);
2334                return;
2335        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
2336                   (!one->mode || S_ISGITLINK(one->mode)) &&
2337                   (!two->mode || S_ISGITLINK(two->mode))) {
2338                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2339                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2340                show_submodule_inline_diff(o->file, one->path ? one->path : two->path,
2341                                line_prefix,
2342                                &one->oid, &two->oid,
2343                                two->dirty_submodule,
2344                                meta, del, add, reset, o);
2345                return;
2346        }
2347
2348        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2349                textconv_one = get_textconv(one);
2350                textconv_two = get_textconv(two);
2351        }
2352
2353        /* Never use a non-valid filename anywhere if at all possible */
2354        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2355        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2356
2357        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2358        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2359        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2360        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2361        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2362        if (lbl[0][0] == '/') {
2363                /* /dev/null */
2364                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2365                if (xfrm_msg)
2366                        strbuf_addstr(&header, xfrm_msg);
2367                must_show_header = 1;
2368        }
2369        else if (lbl[1][0] == '/') {
2370                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2371                if (xfrm_msg)
2372                        strbuf_addstr(&header, xfrm_msg);
2373                must_show_header = 1;
2374        }
2375        else {
2376                if (one->mode != two->mode) {
2377                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2378                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2379                        must_show_header = 1;
2380                }
2381                if (xfrm_msg)
2382                        strbuf_addstr(&header, xfrm_msg);
2383
2384                /*
2385                 * we do not run diff between different kind
2386                 * of objects.
2387                 */
2388                if ((one->mode ^ two->mode) & S_IFMT)
2389                        goto free_ab_and_return;
2390                if (complete_rewrite &&
2391                    (textconv_one || !diff_filespec_is_binary(one)) &&
2392                    (textconv_two || !diff_filespec_is_binary(two))) {
2393                        fprintf(o->file, "%s", header.buf);
2394                        strbuf_reset(&header);
2395                        emit_rewrite_diff(name_a, name_b, one, two,
2396                                                textconv_one, textconv_two, o);
2397                        o->found_changes = 1;
2398                        goto free_ab_and_return;
2399                }
2400        }
2401
2402        if (o->irreversible_delete && lbl[1][0] == '/') {
2403                fprintf(o->file, "%s", header.buf);
2404                strbuf_reset(&header);
2405                goto free_ab_and_return;
2406        } else if (!DIFF_OPT_TST(o, TEXT) &&
2407            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2408              (!textconv_two && diff_filespec_is_binary(two)) )) {
2409                if (!one->data && !two->data &&
2410                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2411                    !DIFF_OPT_TST(o, BINARY)) {
2412                        if (!oidcmp(&one->oid, &two->oid)) {
2413                                if (must_show_header)
2414                                        fprintf(o->file, "%s", header.buf);
2415                                goto free_ab_and_return;
2416                        }
2417                        fprintf(o->file, "%s", header.buf);
2418                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2419                                line_prefix, lbl[0], lbl[1]);
2420                        goto free_ab_and_return;
2421                }
2422                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2423                        die("unable to read files to diff");
2424                /* Quite common confusing case */
2425                if (mf1.size == mf2.size &&
2426                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2427                        if (must_show_header)
2428                                fprintf(o->file, "%s", header.buf);
2429                        goto free_ab_and_return;
2430                }
2431                fprintf(o->file, "%s", header.buf);
2432                strbuf_reset(&header);
2433                if (DIFF_OPT_TST(o, BINARY))
2434                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2435                else
2436                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2437                                line_prefix, lbl[0], lbl[1]);
2438                o->found_changes = 1;
2439        } else {
2440                /* Crazy xdl interfaces.. */
2441                const char *diffopts = getenv("GIT_DIFF_OPTS");
2442                const char *v;
2443                xpparam_t xpp;
2444                xdemitconf_t xecfg;
2445                struct emit_callback ecbdata;
2446                const struct userdiff_funcname *pe;
2447
2448                if (must_show_header) {
2449                        fprintf(o->file, "%s", header.buf);
2450                        strbuf_reset(&header);
2451                }
2452
2453                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2454                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2455
2456                pe = diff_funcname_pattern(one);
2457                if (!pe)
2458                        pe = diff_funcname_pattern(two);
2459
2460                memset(&xpp, 0, sizeof(xpp));
2461                memset(&xecfg, 0, sizeof(xecfg));
2462                memset(&ecbdata, 0, sizeof(ecbdata));
2463                ecbdata.label_path = lbl;
2464                ecbdata.color_diff = want_color(o->use_color);
2465                ecbdata.ws_rule = whitespace_rule(name_b);
2466                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2467                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2468                ecbdata.opt = o;
2469                ecbdata.header = header.len ? &header : NULL;
2470                xpp.flags = o->xdl_opts;
2471                xecfg.ctxlen = o->context;
2472                xecfg.interhunkctxlen = o->interhunkcontext;
2473                xecfg.flags = XDL_EMIT_FUNCNAMES;
2474                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2475                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2476                if (pe)
2477                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2478                if (!diffopts)
2479                        ;
2480                else if (skip_prefix(diffopts, "--unified=", &v))
2481                        xecfg.ctxlen = strtoul(v, NULL, 10);
2482                else if (skip_prefix(diffopts, "-u", &v))
2483                        xecfg.ctxlen = strtoul(v, NULL, 10);
2484                if (o->word_diff)
2485                        init_diff_words_data(&ecbdata, o, one, two);
2486                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2487                                  &xpp, &xecfg))
2488                        die("unable to generate diff for %s", one->path);
2489                if (o->word_diff)
2490                        free_diff_words_data(&ecbdata);
2491                if (textconv_one)
2492                        free(mf1.ptr);
2493                if (textconv_two)
2494                        free(mf2.ptr);
2495                xdiff_clear_find_func(&xecfg);
2496        }
2497
2498 free_ab_and_return:
2499        strbuf_release(&header);
2500        diff_free_filespec_data(one);
2501        diff_free_filespec_data(two);
2502        free(a_one);
2503        free(b_two);
2504        return;
2505}
2506
2507static void builtin_diffstat(const char *name_a, const char *name_b,
2508                             struct diff_filespec *one,
2509                             struct diff_filespec *two,
2510                             struct diffstat_t *diffstat,
2511                             struct diff_options *o,
2512                             struct diff_filepair *p)
2513{
2514        mmfile_t mf1, mf2;
2515        struct diffstat_file *data;
2516        int same_contents;
2517        int complete_rewrite = 0;
2518
2519        if (!DIFF_PAIR_UNMERGED(p)) {
2520                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2521                        complete_rewrite = 1;
2522        }
2523
2524        data = diffstat_add(diffstat, name_a, name_b);
2525        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2526
2527        if (!one || !two) {
2528                data->is_unmerged = 1;
2529                return;
2530        }
2531
2532        same_contents = !oidcmp(&one->oid, &two->oid);
2533
2534        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2535                data->is_binary = 1;
2536                if (same_contents) {
2537                        data->added = 0;
2538                        data->deleted = 0;
2539                } else {
2540                        data->added = diff_filespec_size(two);
2541                        data->deleted = diff_filespec_size(one);
2542                }
2543        }
2544
2545        else if (complete_rewrite) {
2546                diff_populate_filespec(one, 0);
2547                diff_populate_filespec(two, 0);
2548                data->deleted = count_lines(one->data, one->size);
2549                data->added = count_lines(two->data, two->size);
2550        }
2551
2552        else if (!same_contents) {
2553                /* Crazy xdl interfaces.. */
2554                xpparam_t xpp;
2555                xdemitconf_t xecfg;
2556
2557                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2558                        die("unable to read files to diff");
2559
2560                memset(&xpp, 0, sizeof(xpp));
2561                memset(&xecfg, 0, sizeof(xecfg));
2562                xpp.flags = o->xdl_opts;
2563                xecfg.ctxlen = o->context;
2564                xecfg.interhunkctxlen = o->interhunkcontext;
2565                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2566                                  &xpp, &xecfg))
2567                        die("unable to generate diffstat for %s", one->path);
2568        }
2569
2570        diff_free_filespec_data(one);
2571        diff_free_filespec_data(two);
2572}
2573
2574static void builtin_checkdiff(const char *name_a, const char *name_b,
2575                              const char *attr_path,
2576                              struct diff_filespec *one,
2577                              struct diff_filespec *two,
2578                              struct diff_options *o)
2579{
2580        mmfile_t mf1, mf2;
2581        struct checkdiff_t data;
2582
2583        if (!two)
2584                return;
2585
2586        memset(&data, 0, sizeof(data));
2587        data.filename = name_b ? name_b : name_a;
2588        data.lineno = 0;
2589        data.o = o;
2590        data.ws_rule = whitespace_rule(attr_path);
2591        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2592
2593        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2594                die("unable to read files to diff");
2595
2596        /*
2597         * All the other codepaths check both sides, but not checking
2598         * the "old" side here is deliberate.  We are checking the newly
2599         * introduced changes, and as long as the "new" side is text, we
2600         * can and should check what it introduces.
2601         */
2602        if (diff_filespec_is_binary(two))
2603                goto free_and_return;
2604        else {
2605                /* Crazy xdl interfaces.. */
2606                xpparam_t xpp;
2607                xdemitconf_t xecfg;
2608
2609                memset(&xpp, 0, sizeof(xpp));
2610                memset(&xecfg, 0, sizeof(xecfg));
2611                xecfg.ctxlen = 1; /* at least one context line */
2612                xpp.flags = 0;
2613                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2614                                  &xpp, &xecfg))
2615                        die("unable to generate checkdiff for %s", one->path);
2616
2617                if (data.ws_rule & WS_BLANK_AT_EOF) {
2618                        struct emit_callback ecbdata;
2619                        int blank_at_eof;
2620
2621                        ecbdata.ws_rule = data.ws_rule;
2622                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2623                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2624
2625                        if (blank_at_eof) {
2626                                static char *err;
2627                                if (!err)
2628                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2629                                fprintf(o->file, "%s:%d: %s.\n",
2630                                        data.filename, blank_at_eof, err);
2631                                data.status = 1; /* report errors */
2632                        }
2633                }
2634        }
2635 free_and_return:
2636        diff_free_filespec_data(one);
2637        diff_free_filespec_data(two);
2638        if (data.status)
2639                DIFF_OPT_SET(o, CHECK_FAILED);
2640}
2641
2642struct diff_filespec *alloc_filespec(const char *path)
2643{
2644        struct diff_filespec *spec;
2645
2646        FLEXPTR_ALLOC_STR(spec, path, path);
2647        spec->count = 1;
2648        spec->is_binary = -1;
2649        return spec;
2650}
2651
2652void free_filespec(struct diff_filespec *spec)
2653{
2654        if (!--spec->count) {
2655                diff_free_filespec_data(spec);
2656                free(spec);
2657        }
2658}
2659
2660void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2661                   int sha1_valid, unsigned short mode)
2662{
2663        if (mode) {
2664                spec->mode = canon_mode(mode);
2665                hashcpy(spec->oid.hash, sha1);
2666                spec->oid_valid = sha1_valid;
2667        }
2668}
2669
2670/*
2671 * Given a name and sha1 pair, if the index tells us the file in
2672 * the work tree has that object contents, return true, so that
2673 * prepare_temp_file() does not have to inflate and extract.
2674 */
2675static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2676{
2677        const struct cache_entry *ce;
2678        struct stat st;
2679        int pos, len;
2680
2681        /*
2682         * We do not read the cache ourselves here, because the
2683         * benchmark with my previous version that always reads cache
2684         * shows that it makes things worse for diff-tree comparing
2685         * two linux-2.6 kernel trees in an already checked out work
2686         * tree.  This is because most diff-tree comparisons deal with
2687         * only a small number of files, while reading the cache is
2688         * expensive for a large project, and its cost outweighs the
2689         * savings we get by not inflating the object to a temporary
2690         * file.  Practically, this code only helps when we are used
2691         * by diff-cache --cached, which does read the cache before
2692         * calling us.
2693         */
2694        if (!active_cache)
2695                return 0;
2696
2697        /* We want to avoid the working directory if our caller
2698         * doesn't need the data in a normal file, this system
2699         * is rather slow with its stat/open/mmap/close syscalls,
2700         * and the object is contained in a pack file.  The pack
2701         * is probably already open and will be faster to obtain
2702         * the data through than the working directory.  Loose
2703         * objects however would tend to be slower as they need
2704         * to be individually opened and inflated.
2705         */
2706        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2707                return 0;
2708
2709        /*
2710         * Similarly, if we'd have to convert the file contents anyway, that
2711         * makes the optimization not worthwhile.
2712         */
2713        if (!want_file && would_convert_to_git(name))
2714                return 0;
2715
2716        len = strlen(name);
2717        pos = cache_name_pos(name, len);
2718        if (pos < 0)
2719                return 0;
2720        ce = active_cache[pos];
2721
2722        /*
2723         * This is not the sha1 we are looking for, or
2724         * unreusable because it is not a regular file.
2725         */
2726        if (hashcmp(sha1, ce->oid.hash) || !S_ISREG(ce->ce_mode))
2727                return 0;
2728
2729        /*
2730         * If ce is marked as "assume unchanged", there is no
2731         * guarantee that work tree matches what we are looking for.
2732         */
2733        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2734                return 0;
2735
2736        /*
2737         * If ce matches the file in the work tree, we can reuse it.
2738         */
2739        if (ce_uptodate(ce) ||
2740            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2741                return 1;
2742
2743        return 0;
2744}
2745
2746static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2747{
2748        struct strbuf buf = STRBUF_INIT;
2749        char *dirty = "";
2750
2751        /* Are we looking at the work tree? */
2752        if (s->dirty_submodule)
2753                dirty = "-dirty";
2754
2755        strbuf_addf(&buf, "Subproject commit %s%s\n",
2756                    oid_to_hex(&s->oid), dirty);
2757        s->size = buf.len;
2758        if (size_only) {
2759                s->data = NULL;
2760                strbuf_release(&buf);
2761        } else {
2762                s->data = strbuf_detach(&buf, NULL);
2763                s->should_free = 1;
2764        }
2765        return 0;
2766}
2767
2768/*
2769 * While doing rename detection and pickaxe operation, we may need to
2770 * grab the data for the blob (or file) for our own in-core comparison.
2771 * diff_filespec has data and size fields for this purpose.
2772 */
2773int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2774{
2775        int size_only = flags & CHECK_SIZE_ONLY;
2776        int err = 0;
2777        /*
2778         * demote FAIL to WARN to allow inspecting the situation
2779         * instead of refusing.
2780         */
2781        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2782                                    ? SAFE_CRLF_WARN
2783                                    : safe_crlf);
2784
2785        if (!DIFF_FILE_VALID(s))
2786                die("internal error: asking to populate invalid file.");
2787        if (S_ISDIR(s->mode))
2788                return -1;
2789
2790        if (s->data)
2791                return 0;
2792
2793        if (size_only && 0 < s->size)
2794                return 0;
2795
2796        if (S_ISGITLINK(s->mode))
2797                return diff_populate_gitlink(s, size_only);
2798
2799        if (!s->oid_valid ||
2800            reuse_worktree_file(s->path, s->oid.hash, 0)) {
2801                struct strbuf buf = STRBUF_INIT;
2802                struct stat st;
2803                int fd;
2804
2805                if (lstat(s->path, &st) < 0) {
2806                        if (errno == ENOENT) {
2807                        err_empty:
2808                                err = -1;
2809                        empty:
2810                                s->data = (char *)"";
2811                                s->size = 0;
2812                                return err;
2813                        }
2814                }
2815                s->size = xsize_t(st.st_size);
2816                if (!s->size)
2817                        goto empty;
2818                if (S_ISLNK(st.st_mode)) {
2819                        struct strbuf sb = STRBUF_INIT;
2820
2821                        if (strbuf_readlink(&sb, s->path, s->size))
2822                                goto err_empty;
2823                        s->size = sb.len;
2824                        s->data = strbuf_detach(&sb, NULL);
2825                        s->should_free = 1;
2826                        return 0;
2827                }
2828                if (size_only)
2829                        return 0;
2830                if ((flags & CHECK_BINARY) &&
2831                    s->size > big_file_threshold && s->is_binary == -1) {
2832                        s->is_binary = 1;
2833                        return 0;
2834                }
2835                fd = open(s->path, O_RDONLY);
2836                if (fd < 0)
2837                        goto err_empty;
2838                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2839                close(fd);
2840                s->should_munmap = 1;
2841
2842                /*
2843                 * Convert from working tree format to canonical git format
2844                 */
2845                if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
2846                        size_t size = 0;
2847                        munmap(s->data, s->size);
2848                        s->should_munmap = 0;
2849                        s->data = strbuf_detach(&buf, &size);
2850                        s->size = size;
2851                        s->should_free = 1;
2852                }
2853        }
2854        else {
2855                enum object_type type;
2856                if (size_only || (flags & CHECK_BINARY)) {
2857                        type = sha1_object_info(s->oid.hash, &s->size);
2858                        if (type < 0)
2859                                die("unable to read %s",
2860                                    oid_to_hex(&s->oid));
2861                        if (size_only)
2862                                return 0;
2863                        if (s->size > big_file_threshold && s->is_binary == -1) {
2864                                s->is_binary = 1;
2865                                return 0;
2866                        }
2867                }
2868                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
2869                if (!s->data)
2870                        die("unable to read %s", oid_to_hex(&s->oid));
2871                s->should_free = 1;
2872        }
2873        return 0;
2874}
2875
2876void diff_free_filespec_blob(struct diff_filespec *s)
2877{
2878        if (s->should_free)
2879                free(s->data);
2880        else if (s->should_munmap)
2881                munmap(s->data, s->size);
2882
2883        if (s->should_free || s->should_munmap) {
2884                s->should_free = s->should_munmap = 0;
2885                s->data = NULL;
2886        }
2887}
2888
2889void diff_free_filespec_data(struct diff_filespec *s)
2890{
2891        diff_free_filespec_blob(s);
2892        free(s->cnt_data);
2893        s->cnt_data = NULL;
2894}
2895
2896static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2897                           void *blob,
2898                           unsigned long size,
2899                           const struct object_id *oid,
2900                           int mode)
2901{
2902        int fd;
2903        struct strbuf buf = STRBUF_INIT;
2904        struct strbuf template = STRBUF_INIT;
2905        char *path_dup = xstrdup(path);
2906        const char *base = basename(path_dup);
2907
2908        /* Generate "XXXXXX_basename.ext" */
2909        strbuf_addstr(&template, "XXXXXX_");
2910        strbuf_addstr(&template, base);
2911
2912        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
2913        if (fd < 0)
2914                die_errno("unable to create temp-file");
2915        if (convert_to_working_tree(path,
2916                        (const char *)blob, (size_t)size, &buf)) {
2917                blob = buf.buf;
2918                size = buf.len;
2919        }
2920        if (write_in_full(fd, blob, size) != size)
2921                die_errno("unable to write temp-file");
2922        close_tempfile(&temp->tempfile);
2923        temp->name = get_tempfile_path(&temp->tempfile);
2924        oid_to_hex_r(temp->hex, oid);
2925        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
2926        strbuf_release(&buf);
2927        strbuf_release(&template);
2928        free(path_dup);
2929}
2930
2931static struct diff_tempfile *prepare_temp_file(const char *name,
2932                struct diff_filespec *one)
2933{
2934        struct diff_tempfile *temp = claim_diff_tempfile();
2935
2936        if (!DIFF_FILE_VALID(one)) {
2937        not_a_valid_file:
2938                /* A '-' entry produces this for file-2, and
2939                 * a '+' entry produces this for file-1.
2940                 */
2941                temp->name = "/dev/null";
2942                xsnprintf(temp->hex, sizeof(temp->hex), ".");
2943                xsnprintf(temp->mode, sizeof(temp->mode), ".");
2944                return temp;
2945        }
2946
2947        if (!S_ISGITLINK(one->mode) &&
2948            (!one->oid_valid ||
2949             reuse_worktree_file(name, one->oid.hash, 1))) {
2950                struct stat st;
2951                if (lstat(name, &st) < 0) {
2952                        if (errno == ENOENT)
2953                                goto not_a_valid_file;
2954                        die_errno("stat(%s)", name);
2955                }
2956                if (S_ISLNK(st.st_mode)) {
2957                        struct strbuf sb = STRBUF_INIT;
2958                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2959                                die_errno("readlink(%s)", name);
2960                        prep_temp_blob(name, temp, sb.buf, sb.len,
2961                                       (one->oid_valid ?
2962                                        &one->oid : &null_oid),
2963                                       (one->oid_valid ?
2964                                        one->mode : S_IFLNK));
2965                        strbuf_release(&sb);
2966                }
2967                else {
2968                        /* we can borrow from the file in the work tree */
2969                        temp->name = name;
2970                        if (!one->oid_valid)
2971                                sha1_to_hex_r(temp->hex, null_sha1);
2972                        else
2973                                sha1_to_hex_r(temp->hex, one->oid.hash);
2974                        /* Even though we may sometimes borrow the
2975                         * contents from the work tree, we always want
2976                         * one->mode.  mode is trustworthy even when
2977                         * !(one->sha1_valid), as long as
2978                         * DIFF_FILE_VALID(one).
2979                         */
2980                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
2981                }
2982                return temp;
2983        }
2984        else {
2985                if (diff_populate_filespec(one, 0))
2986                        die("cannot read data blob for %s", one->path);
2987                prep_temp_blob(name, temp, one->data, one->size,
2988                               &one->oid, one->mode);
2989        }
2990        return temp;
2991}
2992
2993static void add_external_diff_name(struct argv_array *argv,
2994                                   const char *name,
2995                                   struct diff_filespec *df)
2996{
2997        struct diff_tempfile *temp = prepare_temp_file(name, df);
2998        argv_array_push(argv, temp->name);
2999        argv_array_push(argv, temp->hex);
3000        argv_array_push(argv, temp->mode);
3001}
3002
3003/* An external diff command takes:
3004 *
3005 * diff-cmd name infile1 infile1-sha1 infile1-mode \
3006 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
3007 *
3008 */
3009static void run_external_diff(const char *pgm,
3010                              const char *name,
3011                              const char *other,
3012                              struct diff_filespec *one,
3013                              struct diff_filespec *two,
3014                              const char *xfrm_msg,
3015                              int complete_rewrite,
3016                              struct diff_options *o)
3017{
3018        struct argv_array argv = ARGV_ARRAY_INIT;
3019        struct argv_array env = ARGV_ARRAY_INIT;
3020        struct diff_queue_struct *q = &diff_queued_diff;
3021
3022        argv_array_push(&argv, pgm);
3023        argv_array_push(&argv, name);
3024
3025        if (one && two) {
3026                add_external_diff_name(&argv, name, one);
3027                if (!other)
3028                        add_external_diff_name(&argv, name, two);
3029                else {
3030                        add_external_diff_name(&argv, other, two);
3031                        argv_array_push(&argv, other);
3032                        argv_array_push(&argv, xfrm_msg);
3033                }
3034        }
3035
3036        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3037        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3038
3039        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3040                die(_("external diff died, stopping at %s"), name);
3041
3042        remove_tempfile();
3043        argv_array_clear(&argv);
3044        argv_array_clear(&env);
3045}
3046
3047static int similarity_index(struct diff_filepair *p)
3048{
3049        return p->score * 100 / MAX_SCORE;
3050}
3051
3052static void fill_metainfo(struct strbuf *msg,
3053                          const char *name,
3054                          const char *other,
3055                          struct diff_filespec *one,
3056                          struct diff_filespec *two,
3057                          struct diff_options *o,
3058                          struct diff_filepair *p,
3059                          int *must_show_header,
3060                          int use_color)
3061{
3062        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3063        const char *reset = diff_get_color(use_color, DIFF_RESET);
3064        const char *line_prefix = diff_line_prefix(o);
3065
3066        *must_show_header = 1;
3067        strbuf_init(msg, PATH_MAX * 2 + 300);
3068        switch (p->status) {
3069        case DIFF_STATUS_COPIED:
3070                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3071                            line_prefix, set, similarity_index(p));
3072                strbuf_addf(msg, "%s\n%s%scopy from ",
3073                            reset,  line_prefix, set);
3074                quote_c_style(name, msg, NULL, 0);
3075                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3076                quote_c_style(other, msg, NULL, 0);
3077                strbuf_addf(msg, "%s\n", reset);
3078                break;
3079        case DIFF_STATUS_RENAMED:
3080                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3081                            line_prefix, set, similarity_index(p));
3082                strbuf_addf(msg, "%s\n%s%srename from ",
3083                            reset, line_prefix, set);
3084                quote_c_style(name, msg, NULL, 0);
3085                strbuf_addf(msg, "%s\n%s%srename to ",
3086                            reset, line_prefix, set);
3087                quote_c_style(other, msg, NULL, 0);
3088                strbuf_addf(msg, "%s\n", reset);
3089                break;
3090        case DIFF_STATUS_MODIFIED:
3091                if (p->score) {
3092                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3093                                    line_prefix,
3094                                    set, similarity_index(p), reset);
3095                        break;
3096                }
3097                /* fallthru */
3098        default:
3099                *must_show_header = 0;
3100        }
3101        if (one && two && oidcmp(&one->oid, &two->oid)) {
3102                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3103
3104                if (DIFF_OPT_TST(o, BINARY)) {
3105                        mmfile_t mf;
3106                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3107                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3108                                abbrev = 40;
3109                }
3110                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
3111                            find_unique_abbrev(one->oid.hash, abbrev));
3112                strbuf_addstr(msg, find_unique_abbrev(two->oid.hash, abbrev));
3113                if (one->mode == two->mode)
3114                        strbuf_addf(msg, " %06o", one->mode);
3115                strbuf_addf(msg, "%s\n", reset);
3116        }
3117}
3118
3119static void run_diff_cmd(const char *pgm,
3120                         const char *name,
3121                         const char *other,
3122                         const char *attr_path,
3123                         struct diff_filespec *one,
3124                         struct diff_filespec *two,
3125                         struct strbuf *msg,
3126                         struct diff_options *o,
3127                         struct diff_filepair *p)
3128{
3129        const char *xfrm_msg = NULL;
3130        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3131        int must_show_header = 0;
3132
3133
3134        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3135                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3136                if (drv && drv->external)
3137                        pgm = drv->external;
3138        }
3139
3140        if (msg) {
3141                /*
3142                 * don't use colors when the header is intended for an
3143                 * external diff driver
3144                 */
3145                fill_metainfo(msg, name, other, one, two, o, p,
3146                              &must_show_header,
3147                              want_color(o->use_color) && !pgm);
3148                xfrm_msg = msg->len ? msg->buf : NULL;
3149        }
3150
3151        if (pgm) {
3152                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3153                                  complete_rewrite, o);
3154                return;
3155        }
3156        if (one && two)
3157                builtin_diff(name, other ? other : name,
3158                             one, two, xfrm_msg, must_show_header,
3159                             o, complete_rewrite);
3160        else
3161                fprintf(o->file, "* Unmerged path %s\n", name);
3162}
3163
3164static void diff_fill_sha1_info(struct diff_filespec *one)
3165{
3166        if (DIFF_FILE_VALID(one)) {
3167                if (!one->oid_valid) {
3168                        struct stat st;
3169                        if (one->is_stdin) {
3170                                oidclr(&one->oid);
3171                                return;
3172                        }
3173                        if (lstat(one->path, &st) < 0)
3174                                die_errno("stat '%s'", one->path);
3175                        if (index_path(one->oid.hash, one->path, &st, 0))
3176                                die("cannot hash %s", one->path);
3177                }
3178        }
3179        else
3180                oidclr(&one->oid);
3181}
3182
3183static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3184{
3185        /* Strip the prefix but do not molest /dev/null and absolute paths */
3186        if (*namep && **namep != '/') {
3187                *namep += prefix_length;
3188                if (**namep == '/')
3189                        ++*namep;
3190        }
3191        if (*otherp && **otherp != '/') {
3192                *otherp += prefix_length;
3193                if (**otherp == '/')
3194                        ++*otherp;
3195        }
3196}
3197
3198static void run_diff(struct diff_filepair *p, struct diff_options *o)
3199{
3200        const char *pgm = external_diff();
3201        struct strbuf msg;
3202        struct diff_filespec *one = p->one;
3203        struct diff_filespec *two = p->two;
3204        const char *name;
3205        const char *other;
3206        const char *attr_path;
3207
3208        name  = p->one->path;
3209        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3210        attr_path = name;
3211        if (o->prefix_length)
3212                strip_prefix(o->prefix_length, &name, &other);
3213
3214        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3215                pgm = NULL;
3216
3217        if (DIFF_PAIR_UNMERGED(p)) {
3218                run_diff_cmd(pgm, name, NULL, attr_path,
3219                             NULL, NULL, NULL, o, p);
3220                return;
3221        }
3222
3223        diff_fill_sha1_info(one);
3224        diff_fill_sha1_info(two);
3225
3226        if (!pgm &&
3227            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3228            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3229                /*
3230                 * a filepair that changes between file and symlink
3231                 * needs to be split into deletion and creation.
3232                 */
3233                struct diff_filespec *null = alloc_filespec(two->path);
3234                run_diff_cmd(NULL, name, other, attr_path,
3235                             one, null, &msg, o, p);
3236                free(null);
3237                strbuf_release(&msg);
3238
3239                null = alloc_filespec(one->path);
3240                run_diff_cmd(NULL, name, other, attr_path,
3241                             null, two, &msg, o, p);
3242                free(null);
3243        }
3244        else
3245                run_diff_cmd(pgm, name, other, attr_path,
3246                             one, two, &msg, o, p);
3247
3248        strbuf_release(&msg);
3249}
3250
3251static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3252                         struct diffstat_t *diffstat)
3253{
3254        const char *name;
3255        const char *other;
3256
3257        if (DIFF_PAIR_UNMERGED(p)) {
3258                /* unmerged */
3259                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3260                return;
3261        }
3262
3263        name = p->one->path;
3264        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3265
3266        if (o->prefix_length)
3267                strip_prefix(o->prefix_length, &name, &other);
3268
3269        diff_fill_sha1_info(p->one);
3270        diff_fill_sha1_info(p->two);
3271
3272        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3273}
3274
3275static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3276{
3277        const char *name;
3278        const char *other;
3279        const char *attr_path;
3280
3281        if (DIFF_PAIR_UNMERGED(p)) {
3282                /* unmerged */
3283                return;
3284        }
3285
3286        name = p->one->path;
3287        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3288        attr_path = other ? other : name;
3289
3290        if (o->prefix_length)
3291                strip_prefix(o->prefix_length, &name, &other);
3292
3293        diff_fill_sha1_info(p->one);
3294        diff_fill_sha1_info(p->two);
3295
3296        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3297}
3298
3299void diff_setup(struct diff_options *options)
3300{
3301        memcpy(options, &default_diff_options, sizeof(*options));
3302
3303        options->file = stdout;
3304
3305        options->line_termination = '\n';
3306        options->break_opt = -1;
3307        options->rename_limit = -1;
3308        options->dirstat_permille = diff_dirstat_permille_default;
3309        options->context = diff_context_default;
3310        options->ws_error_highlight = WSEH_NEW;
3311        DIFF_OPT_SET(options, RENAME_EMPTY);
3312
3313        /* pathchange left =NULL by default */
3314        options->change = diff_change;
3315        options->add_remove = diff_addremove;
3316        options->use_color = diff_use_color_default;
3317        options->detect_rename = diff_detect_rename_default;
3318        options->xdl_opts |= diff_algorithm;
3319        if (diff_indent_heuristic)
3320                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3321        else if (diff_compaction_heuristic)
3322                DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
3323
3324        options->orderfile = diff_order_file_cfg;
3325
3326        if (diff_no_prefix) {
3327                options->a_prefix = options->b_prefix = "";
3328        } else if (!diff_mnemonic_prefix) {
3329                options->a_prefix = "a/";
3330                options->b_prefix = "b/";
3331        }
3332}
3333
3334void diff_setup_done(struct diff_options *options)
3335{
3336        int count = 0;
3337
3338        if (options->set_default)
3339                options->set_default(options);
3340
3341        if (options->output_format & DIFF_FORMAT_NAME)
3342                count++;
3343        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3344                count++;
3345        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3346                count++;
3347        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3348                count++;
3349        if (count > 1)
3350                die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
3351
3352        /*
3353         * Most of the time we can say "there are changes"
3354         * only by checking if there are changed paths, but
3355         * --ignore-whitespace* options force us to look
3356         * inside contents.
3357         */
3358
3359        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3360            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3361            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3362                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3363        else
3364                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3365
3366        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3367                options->detect_rename = DIFF_DETECT_COPY;
3368
3369        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3370                options->prefix = NULL;
3371        if (options->prefix)
3372                options->prefix_length = strlen(options->prefix);
3373        else
3374                options->prefix_length = 0;
3375
3376        if (options->output_format & (DIFF_FORMAT_NAME |
3377                                      DIFF_FORMAT_NAME_STATUS |
3378                                      DIFF_FORMAT_CHECKDIFF |
3379                                      DIFF_FORMAT_NO_OUTPUT))
3380                options->output_format &= ~(DIFF_FORMAT_RAW |
3381                                            DIFF_FORMAT_NUMSTAT |
3382                                            DIFF_FORMAT_DIFFSTAT |
3383                                            DIFF_FORMAT_SHORTSTAT |
3384                                            DIFF_FORMAT_DIRSTAT |
3385                                            DIFF_FORMAT_SUMMARY |
3386                                            DIFF_FORMAT_PATCH);
3387
3388        /*
3389         * These cases always need recursive; we do not drop caller-supplied
3390         * recursive bits for other formats here.
3391         */
3392        if (options->output_format & (DIFF_FORMAT_PATCH |
3393                                      DIFF_FORMAT_NUMSTAT |
3394                                      DIFF_FORMAT_DIFFSTAT |
3395                                      DIFF_FORMAT_SHORTSTAT |
3396                                      DIFF_FORMAT_DIRSTAT |
3397                                      DIFF_FORMAT_SUMMARY |
3398                                      DIFF_FORMAT_CHECKDIFF))
3399                DIFF_OPT_SET(options, RECURSIVE);
3400        /*
3401         * Also pickaxe would not work very well if you do not say recursive
3402         */
3403        if (options->pickaxe)
3404                DIFF_OPT_SET(options, RECURSIVE);
3405        /*
3406         * When patches are generated, submodules diffed against the work tree
3407         * must be checked for dirtiness too so it can be shown in the output
3408         */
3409        if (options->output_format & DIFF_FORMAT_PATCH)
3410                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3411
3412        if (options->detect_rename && options->rename_limit < 0)
3413                options->rename_limit = diff_rename_limit_default;
3414        if (options->setup & DIFF_SETUP_USE_CACHE) {
3415                if (!active_cache)
3416                        /* read-cache does not die even when it fails
3417                         * so it is safe for us to do this here.  Also
3418                         * it does not smudge active_cache or active_nr
3419                         * when it fails, so we do not have to worry about
3420                         * cleaning it up ourselves either.
3421                         */
3422                        read_cache();
3423        }
3424        if (options->abbrev <= 0 || 40 < options->abbrev)
3425                options->abbrev = 40; /* full */
3426
3427        /*
3428         * It does not make sense to show the first hit we happened
3429         * to have found.  It does not make sense not to return with
3430         * exit code in such a case either.
3431         */
3432        if (DIFF_OPT_TST(options, QUICK)) {
3433                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3434                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3435        }
3436
3437        options->diff_path_counter = 0;
3438
3439        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3440                die(_("--follow requires exactly one pathspec"));
3441}
3442
3443static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3444{
3445        char c, *eq;
3446        int len;
3447
3448        if (*arg != '-')
3449                return 0;
3450        c = *++arg;
3451        if (!c)
3452                return 0;
3453        if (c == arg_short) {
3454                c = *++arg;
3455                if (!c)
3456                        return 1;
3457                if (val && isdigit(c)) {
3458                        char *end;
3459                        int n = strtoul(arg, &end, 10);
3460                        if (*end)
3461                                return 0;
3462                        *val = n;
3463                        return 1;
3464                }
3465                return 0;
3466        }
3467        if (c != '-')
3468                return 0;
3469        arg++;
3470        eq = strchrnul(arg, '=');
3471        len = eq - arg;
3472        if (!len || strncmp(arg, arg_long, len))
3473                return 0;
3474        if (*eq) {
3475                int n;
3476                char *end;
3477                if (!isdigit(*++eq))
3478                        return 0;
3479                n = strtoul(eq, &end, 10);
3480                if (*end)
3481                        return 0;
3482                *val = n;
3483        }
3484        return 1;
3485}
3486
3487static int diff_scoreopt_parse(const char *opt);
3488
3489static inline int short_opt(char opt, const char **argv,
3490                            const char **optarg)
3491{
3492        const char *arg = argv[0];
3493        if (arg[0] != '-' || arg[1] != opt)
3494                return 0;
3495        if (arg[2] != '\0') {
3496                *optarg = arg + 2;
3497                return 1;
3498        }
3499        if (!argv[1])
3500                die("Option '%c' requires a value", opt);
3501        *optarg = argv[1];
3502        return 2;
3503}
3504
3505int parse_long_opt(const char *opt, const char **argv,
3506                   const char **optarg)
3507{
3508        const char *arg = argv[0];
3509        if (!skip_prefix(arg, "--", &arg))
3510                return 0;
3511        if (!skip_prefix(arg, opt, &arg))
3512                return 0;
3513        if (*arg == '=') { /* stuck form: --option=value */
3514                *optarg = arg + 1;
3515                return 1;
3516        }
3517        if (*arg != '\0')
3518                return 0;
3519        /* separate form: --option value */
3520        if (!argv[1])
3521                die("Option '--%s' requires a value", opt);
3522        *optarg = argv[1];
3523        return 2;
3524}
3525
3526static int stat_opt(struct diff_options *options, const char **av)
3527{
3528        const char *arg = av[0];
3529        char *end;
3530        int width = options->stat_width;
3531        int name_width = options->stat_name_width;
3532        int graph_width = options->stat_graph_width;
3533        int count = options->stat_count;
3534        int argcount = 1;
3535
3536        if (!skip_prefix(arg, "--stat", &arg))
3537                die("BUG: stat option does not begin with --stat: %s", arg);
3538        end = (char *)arg;
3539
3540        switch (*arg) {
3541        case '-':
3542                if (skip_prefix(arg, "-width", &arg)) {
3543                        if (*arg == '=')
3544                                width = strtoul(arg + 1, &end, 10);
3545                        else if (!*arg && !av[1])
3546                                die_want_option("--stat-width");
3547                        else if (!*arg) {
3548                                width = strtoul(av[1], &end, 10);
3549                                argcount = 2;
3550                        }
3551                } else if (skip_prefix(arg, "-name-width", &arg)) {
3552                        if (*arg == '=')
3553                                name_width = strtoul(arg + 1, &end, 10);
3554                        else if (!*arg && !av[1])
3555                                die_want_option("--stat-name-width");
3556                        else if (!*arg) {
3557                                name_width = strtoul(av[1], &end, 10);
3558                                argcount = 2;
3559                        }
3560                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3561                        if (*arg == '=')
3562                                graph_width = strtoul(arg + 1, &end, 10);
3563                        else if (!*arg && !av[1])
3564                                die_want_option("--stat-graph-width");
3565                        else if (!*arg) {
3566                                graph_width = strtoul(av[1], &end, 10);
3567                                argcount = 2;
3568                        }
3569                } else if (skip_prefix(arg, "-count", &arg)) {
3570                        if (*arg == '=')
3571                                count = strtoul(arg + 1, &end, 10);
3572                        else if (!*arg && !av[1])
3573                                die_want_option("--stat-count");
3574                        else if (!*arg) {
3575                                count = strtoul(av[1], &end, 10);
3576                                argcount = 2;
3577                        }
3578                }
3579                break;
3580        case '=':
3581                width = strtoul(arg+1, &end, 10);
3582                if (*end == ',')
3583                        name_width = strtoul(end+1, &end, 10);
3584                if (*end == ',')
3585                        count = strtoul(end+1, &end, 10);
3586        }
3587
3588        /* Important! This checks all the error cases! */
3589        if (*end)
3590                return 0;
3591        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3592        options->stat_name_width = name_width;
3593        options->stat_graph_width = graph_width;
3594        options->stat_width = width;
3595        options->stat_count = count;
3596        return argcount;
3597}
3598
3599static int parse_dirstat_opt(struct diff_options *options, const char *params)
3600{
3601        struct strbuf errmsg = STRBUF_INIT;
3602        if (parse_dirstat_params(options, params, &errmsg))
3603                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3604                    errmsg.buf);
3605        strbuf_release(&errmsg);
3606        /*
3607         * The caller knows a dirstat-related option is given from the command
3608         * line; allow it to say "return this_function();"
3609         */
3610        options->output_format |= DIFF_FORMAT_DIRSTAT;
3611        return 1;
3612}
3613
3614static int parse_submodule_opt(struct diff_options *options, const char *value)
3615{
3616        if (parse_submodule_params(options, value))
3617                die(_("Failed to parse --submodule option parameter: '%s'"),
3618                        value);
3619        return 1;
3620}
3621
3622static const char diff_status_letters[] = {
3623        DIFF_STATUS_ADDED,
3624        DIFF_STATUS_COPIED,
3625        DIFF_STATUS_DELETED,
3626        DIFF_STATUS_MODIFIED,
3627        DIFF_STATUS_RENAMED,
3628        DIFF_STATUS_TYPE_CHANGED,
3629        DIFF_STATUS_UNKNOWN,
3630        DIFF_STATUS_UNMERGED,
3631        DIFF_STATUS_FILTER_AON,
3632        DIFF_STATUS_FILTER_BROKEN,
3633        '\0',
3634};
3635
3636static unsigned int filter_bit['Z' + 1];
3637
3638static void prepare_filter_bits(void)
3639{
3640        int i;
3641
3642        if (!filter_bit[DIFF_STATUS_ADDED]) {
3643                for (i = 0; diff_status_letters[i]; i++)
3644                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3645        }
3646}
3647
3648static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3649{
3650        return opt->filter & filter_bit[(int) status];
3651}
3652
3653static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3654{
3655        int i, optch;
3656
3657        prepare_filter_bits();
3658
3659        /*
3660         * If there is a negation e.g. 'd' in the input, and we haven't
3661         * initialized the filter field with another --diff-filter, start
3662         * from full set of bits, except for AON.
3663         */
3664        if (!opt->filter) {
3665                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3666                        if (optch < 'a' || 'z' < optch)
3667                                continue;
3668                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3669                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3670                        break;
3671                }
3672        }
3673
3674        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3675                unsigned int bit;
3676                int negate;
3677
3678                if ('a' <= optch && optch <= 'z') {
3679                        negate = 1;
3680                        optch = toupper(optch);
3681                } else {
3682                        negate = 0;
3683                }
3684
3685                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3686                if (!bit)
3687                        return optarg[i];
3688                if (negate)
3689                        opt->filter &= ~bit;
3690                else
3691                        opt->filter |= bit;
3692        }
3693        return 0;
3694}
3695
3696static void enable_patch_output(int *fmt) {
3697        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3698        *fmt |= DIFF_FORMAT_PATCH;
3699}
3700
3701static int parse_one_token(const char **arg, const char *token)
3702{
3703        const char *rest;
3704        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
3705                *arg = rest;
3706                return 1;
3707        }
3708        return 0;
3709}
3710
3711static int parse_ws_error_highlight(struct diff_options *opt, const char *arg)
3712{
3713        const char *orig_arg = arg;
3714        unsigned val = 0;
3715        while (*arg) {
3716                if (parse_one_token(&arg, "none"))
3717                        val = 0;
3718                else if (parse_one_token(&arg, "default"))
3719                        val = WSEH_NEW;
3720                else if (parse_one_token(&arg, "all"))
3721                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
3722                else if (parse_one_token(&arg, "new"))
3723                        val |= WSEH_NEW;
3724                else if (parse_one_token(&arg, "old"))
3725                        val |= WSEH_OLD;
3726                else if (parse_one_token(&arg, "context"))
3727                        val |= WSEH_CONTEXT;
3728                else {
3729                        error("unknown value after ws-error-highlight=%.*s",
3730                              (int)(arg - orig_arg), orig_arg);
3731                        return 0;
3732                }
3733                if (*arg)
3734                        arg++;
3735        }
3736        opt->ws_error_highlight = val;
3737        return 1;
3738}
3739
3740int diff_opt_parse(struct diff_options *options,
3741                   const char **av, int ac, const char *prefix)
3742{
3743        const char *arg = av[0];
3744        const char *optarg;
3745        int argcount;
3746
3747        if (!prefix)
3748                prefix = "";
3749
3750        /* Output format options */
3751        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3752            || opt_arg(arg, 'U', "unified", &options->context))
3753                enable_patch_output(&options->output_format);
3754        else if (!strcmp(arg, "--raw"))
3755                options->output_format |= DIFF_FORMAT_RAW;
3756        else if (!strcmp(arg, "--patch-with-raw")) {
3757                enable_patch_output(&options->output_format);
3758                options->output_format |= DIFF_FORMAT_RAW;
3759        } else if (!strcmp(arg, "--numstat"))
3760                options->output_format |= DIFF_FORMAT_NUMSTAT;
3761        else if (!strcmp(arg, "--shortstat"))
3762                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3763        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3764                return parse_dirstat_opt(options, "");
3765        else if (skip_prefix(arg, "-X", &arg))
3766                return parse_dirstat_opt(options, arg);
3767        else if (skip_prefix(arg, "--dirstat=", &arg))
3768                return parse_dirstat_opt(options, arg);
3769        else if (!strcmp(arg, "--cumulative"))
3770                return parse_dirstat_opt(options, "cumulative");
3771        else if (!strcmp(arg, "--dirstat-by-file"))
3772                return parse_dirstat_opt(options, "files");
3773        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3774                parse_dirstat_opt(options, "files");
3775                return parse_dirstat_opt(options, arg);
3776        }
3777        else if (!strcmp(arg, "--check"))
3778                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3779        else if (!strcmp(arg, "--summary"))
3780                options->output_format |= DIFF_FORMAT_SUMMARY;
3781        else if (!strcmp(arg, "--patch-with-stat")) {
3782                enable_patch_output(&options->output_format);
3783                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3784        } else if (!strcmp(arg, "--name-only"))
3785                options->output_format |= DIFF_FORMAT_NAME;
3786        else if (!strcmp(arg, "--name-status"))
3787                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3788        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3789                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3790        else if (starts_with(arg, "--stat"))
3791                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3792                return stat_opt(options, av);
3793
3794        /* renames options */
3795        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3796                 !strcmp(arg, "--break-rewrites")) {
3797                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3798                        return error("invalid argument to -B: %s", arg+2);
3799        }
3800        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3801                 !strcmp(arg, "--find-renames")) {
3802                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3803                        return error("invalid argument to -M: %s", arg+2);
3804                options->detect_rename = DIFF_DETECT_RENAME;
3805        }
3806        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3807                options->irreversible_delete = 1;
3808        }
3809        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3810                 !strcmp(arg, "--find-copies")) {
3811                if (options->detect_rename == DIFF_DETECT_COPY)
3812                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3813                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3814                        return error("invalid argument to -C: %s", arg+2);
3815                options->detect_rename = DIFF_DETECT_COPY;
3816        }
3817        else if (!strcmp(arg, "--no-renames"))
3818                options->detect_rename = 0;
3819        else if (!strcmp(arg, "--rename-empty"))
3820                DIFF_OPT_SET(options, RENAME_EMPTY);
3821        else if (!strcmp(arg, "--no-rename-empty"))
3822                DIFF_OPT_CLR(options, RENAME_EMPTY);
3823        else if (!strcmp(arg, "--relative"))
3824                DIFF_OPT_SET(options, RELATIVE_NAME);
3825        else if (skip_prefix(arg, "--relative=", &arg)) {
3826                DIFF_OPT_SET(options, RELATIVE_NAME);
3827                options->prefix = arg;
3828        }
3829
3830        /* xdiff options */
3831        else if (!strcmp(arg, "--minimal"))
3832                DIFF_XDL_SET(options, NEED_MINIMAL);
3833        else if (!strcmp(arg, "--no-minimal"))
3834                DIFF_XDL_CLR(options, NEED_MINIMAL);
3835        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3836                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3837        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3838                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3839        else if (!strcmp(arg, "--ignore-space-at-eol"))
3840                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3841        else if (!strcmp(arg, "--ignore-blank-lines"))
3842                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3843        else if (!strcmp(arg, "--indent-heuristic")) {
3844                DIFF_XDL_SET(options, INDENT_HEURISTIC);
3845                DIFF_XDL_CLR(options, COMPACTION_HEURISTIC);
3846        } else if (!strcmp(arg, "--no-indent-heuristic"))
3847                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
3848        else if (!strcmp(arg, "--compaction-heuristic")) {
3849                DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
3850                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
3851        } else if (!strcmp(arg, "--no-compaction-heuristic"))
3852                DIFF_XDL_CLR(options, COMPACTION_HEURISTIC);
3853        else if (!strcmp(arg, "--patience"))
3854                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3855        else if (!strcmp(arg, "--histogram"))
3856                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3857        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3858                long value = parse_algorithm_value(optarg);
3859                if (value < 0)
3860                        return error("option diff-algorithm accepts \"myers\", "
3861                                     "\"minimal\", \"patience\" and \"histogram\"");
3862                /* clear out previous settings */
3863                DIFF_XDL_CLR(options, NEED_MINIMAL);
3864                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3865                options->xdl_opts |= value;
3866                return argcount;
3867        }
3868
3869        /* flags options */
3870        else if (!strcmp(arg, "--binary")) {
3871                enable_patch_output(&options->output_format);
3872                DIFF_OPT_SET(options, BINARY);
3873        }
3874        else if (!strcmp(arg, "--full-index"))
3875                DIFF_OPT_SET(options, FULL_INDEX);
3876        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3877                DIFF_OPT_SET(options, TEXT);
3878        else if (!strcmp(arg, "-R"))
3879                DIFF_OPT_SET(options, REVERSE_DIFF);
3880        else if (!strcmp(arg, "--find-copies-harder"))
3881                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3882        else if (!strcmp(arg, "--follow"))
3883                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3884        else if (!strcmp(arg, "--no-follow")) {
3885                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3886                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
3887        } else if (!strcmp(arg, "--color"))
3888                options->use_color = 1;
3889        else if (skip_prefix(arg, "--color=", &arg)) {
3890                int value = git_config_colorbool(NULL, arg);
3891                if (value < 0)
3892                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3893                options->use_color = value;
3894        }
3895        else if (!strcmp(arg, "--no-color"))
3896                options->use_color = 0;
3897        else if (!strcmp(arg, "--color-words")) {
3898                options->use_color = 1;
3899                options->word_diff = DIFF_WORDS_COLOR;
3900        }
3901        else if (skip_prefix(arg, "--color-words=", &arg)) {
3902                options->use_color = 1;
3903                options->word_diff = DIFF_WORDS_COLOR;
3904                options->word_regex = arg;
3905        }
3906        else if (!strcmp(arg, "--word-diff")) {
3907                if (options->word_diff == DIFF_WORDS_NONE)
3908                        options->word_diff = DIFF_WORDS_PLAIN;
3909        }
3910        else if (skip_prefix(arg, "--word-diff=", &arg)) {
3911                if (!strcmp(arg, "plain"))
3912                        options->word_diff = DIFF_WORDS_PLAIN;
3913                else if (!strcmp(arg, "color")) {
3914                        options->use_color = 1;
3915                        options->word_diff = DIFF_WORDS_COLOR;
3916                }
3917                else if (!strcmp(arg, "porcelain"))
3918                        options->word_diff = DIFF_WORDS_PORCELAIN;
3919                else if (!strcmp(arg, "none"))
3920                        options->word_diff = DIFF_WORDS_NONE;
3921                else
3922                        die("bad --word-diff argument: %s", arg);
3923        }
3924        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3925                if (options->word_diff == DIFF_WORDS_NONE)
3926                        options->word_diff = DIFF_WORDS_PLAIN;
3927                options->word_regex = optarg;
3928                return argcount;
3929        }
3930        else if (!strcmp(arg, "--exit-code"))
3931                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3932        else if (!strcmp(arg, "--quiet"))
3933                DIFF_OPT_SET(options, QUICK);
3934        else if (!strcmp(arg, "--ext-diff"))
3935                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3936        else if (!strcmp(arg, "--no-ext-diff"))
3937                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3938        else if (!strcmp(arg, "--textconv"))
3939                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3940        else if (!strcmp(arg, "--no-textconv"))
3941                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3942        else if (!strcmp(arg, "--ignore-submodules")) {
3943                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3944                handle_ignore_submodules_arg(options, "all");
3945        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
3946                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3947                handle_ignore_submodules_arg(options, arg);
3948        } else if (!strcmp(arg, "--submodule"))
3949                options->submodule_format = DIFF_SUBMODULE_LOG;
3950        else if (skip_prefix(arg, "--submodule=", &arg))
3951                return parse_submodule_opt(options, arg);
3952        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
3953                return parse_ws_error_highlight(options, arg);
3954
3955        /* misc options */
3956        else if (!strcmp(arg, "-z"))
3957                options->line_termination = 0;
3958        else if ((argcount = short_opt('l', av, &optarg))) {
3959                options->rename_limit = strtoul(optarg, NULL, 10);
3960                return argcount;
3961        }
3962        else if ((argcount = short_opt('S', av, &optarg))) {
3963                options->pickaxe = optarg;
3964                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3965                return argcount;
3966        } else if ((argcount = short_opt('G', av, &optarg))) {
3967                options->pickaxe = optarg;
3968                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3969                return argcount;
3970        }
3971        else if (!strcmp(arg, "--pickaxe-all"))
3972                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3973        else if (!strcmp(arg, "--pickaxe-regex"))
3974                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3975        else if ((argcount = short_opt('O', av, &optarg))) {
3976                const char *path = prefix_filename(prefix, strlen(prefix), optarg);
3977                options->orderfile = xstrdup(path);
3978                return argcount;
3979        }
3980        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3981                int offending = parse_diff_filter_opt(optarg, options);
3982                if (offending)
3983                        die("unknown change class '%c' in --diff-filter=%s",
3984                            offending, optarg);
3985                return argcount;
3986        }
3987        else if (!strcmp(arg, "--abbrev"))
3988                options->abbrev = DEFAULT_ABBREV;
3989        else if (skip_prefix(arg, "--abbrev=", &arg)) {
3990                options->abbrev = strtoul(arg, NULL, 10);
3991                if (options->abbrev < MINIMUM_ABBREV)
3992                        options->abbrev = MINIMUM_ABBREV;
3993                else if (40 < options->abbrev)
3994                        options->abbrev = 40;
3995        }
3996        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3997                options->a_prefix = optarg;
3998                return argcount;
3999        }
4000        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
4001                options->line_prefix = optarg;
4002                options->line_prefix_length = strlen(options->line_prefix);
4003                graph_setup_line_prefix(options);
4004                return argcount;
4005        }
4006        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
4007                options->b_prefix = optarg;
4008                return argcount;
4009        }
4010        else if (!strcmp(arg, "--no-prefix"))
4011                options->a_prefix = options->b_prefix = "";
4012        else if (opt_arg(arg, '\0', "inter-hunk-context",
4013                         &options->interhunkcontext))
4014                ;
4015        else if (!strcmp(arg, "-W"))
4016                DIFF_OPT_SET(options, FUNCCONTEXT);
4017        else if (!strcmp(arg, "--function-context"))
4018                DIFF_OPT_SET(options, FUNCCONTEXT);
4019        else if (!strcmp(arg, "--no-function-context"))
4020                DIFF_OPT_CLR(options, FUNCCONTEXT);
4021        else if ((argcount = parse_long_opt("output", av, &optarg))) {
4022                const char *path = prefix_filename(prefix, strlen(prefix), optarg);
4023                options->file = fopen(path, "w");
4024                if (!options->file)
4025                        die_errno("Could not open '%s'", path);
4026                options->close_file = 1;
4027                if (options->use_color != GIT_COLOR_ALWAYS)
4028                        options->use_color = GIT_COLOR_NEVER;
4029                return argcount;
4030        } else
4031                return 0;
4032        return 1;
4033}
4034
4035int parse_rename_score(const char **cp_p)
4036{
4037        unsigned long num, scale;
4038        int ch, dot;
4039        const char *cp = *cp_p;
4040
4041        num = 0;
4042        scale = 1;
4043        dot = 0;
4044        for (;;) {
4045                ch = *cp;
4046                if ( !dot && ch == '.' ) {
4047                        scale = 1;
4048                        dot = 1;
4049                } else if ( ch == '%' ) {
4050                        scale = dot ? scale*100 : 100;
4051                        cp++;   /* % is always at the end */
4052                        break;
4053                } else if ( ch >= '0' && ch <= '9' ) {
4054                        if ( scale < 100000 ) {
4055                                scale *= 10;
4056                                num = (num*10) + (ch-'0');
4057                        }
4058                } else {
4059                        break;
4060                }
4061                cp++;
4062        }
4063        *cp_p = cp;
4064
4065        /* user says num divided by scale and we say internally that
4066         * is MAX_SCORE * num / scale.
4067         */
4068        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4069}
4070
4071static int diff_scoreopt_parse(const char *opt)
4072{
4073        int opt1, opt2, cmd;
4074
4075        if (*opt++ != '-')
4076                return -1;
4077        cmd = *opt++;
4078        if (cmd == '-') {
4079                /* convert the long-form arguments into short-form versions */
4080                if (skip_prefix(opt, "break-rewrites", &opt)) {
4081                        if (*opt == 0 || *opt++ == '=')
4082                                cmd = 'B';
4083                } else if (skip_prefix(opt, "find-copies", &opt)) {
4084                        if (*opt == 0 || *opt++ == '=')
4085                                cmd = 'C';
4086                } else if (skip_prefix(opt, "find-renames", &opt)) {
4087                        if (*opt == 0 || *opt++ == '=')
4088                                cmd = 'M';
4089                }
4090        }
4091        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4092                return -1; /* that is not a -M, -C, or -B option */
4093
4094        opt1 = parse_rename_score(&opt);
4095        if (cmd != 'B')
4096                opt2 = 0;
4097        else {
4098                if (*opt == 0)
4099                        opt2 = 0;
4100                else if (*opt != '/')
4101                        return -1; /* we expect -B80/99 or -B80 */
4102                else {
4103                        opt++;
4104                        opt2 = parse_rename_score(&opt);
4105                }
4106        }
4107        if (*opt != 0)
4108                return -1;
4109        return opt1 | (opt2 << 16);
4110}
4111
4112struct diff_queue_struct diff_queued_diff;
4113
4114void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4115{
4116        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4117        queue->queue[queue->nr++] = dp;
4118}
4119
4120struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4121                                 struct diff_filespec *one,
4122                                 struct diff_filespec *two)
4123{
4124        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4125        dp->one = one;
4126        dp->two = two;
4127        if (queue)
4128                diff_q(queue, dp);
4129        return dp;
4130}
4131
4132void diff_free_filepair(struct diff_filepair *p)
4133{
4134        free_filespec(p->one);
4135        free_filespec(p->two);
4136        free(p);
4137}
4138
4139/* This is different from find_unique_abbrev() in that
4140 * it stuffs the result with dots for alignment.
4141 */
4142const char *diff_unique_abbrev(const unsigned char *sha1, int len)
4143{
4144        int abblen;
4145        const char *abbrev;
4146        if (len == 40)
4147                return sha1_to_hex(sha1);
4148
4149        abbrev = find_unique_abbrev(sha1, len);
4150        abblen = strlen(abbrev);
4151        if (abblen < 37) {
4152                static char hex[41];
4153                if (len < abblen && abblen <= len + 2)
4154                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4155                else
4156                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4157                return hex;
4158        }
4159        return sha1_to_hex(sha1);
4160}
4161
4162static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4163{
4164        int line_termination = opt->line_termination;
4165        int inter_name_termination = line_termination ? '\t' : '\0';
4166
4167        fprintf(opt->file, "%s", diff_line_prefix(opt));
4168        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4169                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4170                        diff_unique_abbrev(p->one->oid.hash, opt->abbrev));
4171                fprintf(opt->file, "%s ",
4172                        diff_unique_abbrev(p->two->oid.hash, opt->abbrev));
4173        }
4174        if (p->score) {
4175                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4176                        inter_name_termination);
4177        } else {
4178                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4179        }
4180
4181        if (p->status == DIFF_STATUS_COPIED ||
4182            p->status == DIFF_STATUS_RENAMED) {
4183                const char *name_a, *name_b;
4184                name_a = p->one->path;
4185                name_b = p->two->path;
4186                strip_prefix(opt->prefix_length, &name_a, &name_b);
4187                write_name_quoted(name_a, opt->file, inter_name_termination);
4188                write_name_quoted(name_b, opt->file, line_termination);
4189        } else {
4190                const char *name_a, *name_b;
4191                name_a = p->one->mode ? p->one->path : p->two->path;
4192                name_b = NULL;
4193                strip_prefix(opt->prefix_length, &name_a, &name_b);
4194                write_name_quoted(name_a, opt->file, line_termination);
4195        }
4196}
4197
4198int diff_unmodified_pair(struct diff_filepair *p)
4199{
4200        /* This function is written stricter than necessary to support
4201         * the currently implemented transformers, but the idea is to
4202         * let transformers to produce diff_filepairs any way they want,
4203         * and filter and clean them up here before producing the output.
4204         */
4205        struct diff_filespec *one = p->one, *two = p->two;
4206
4207        if (DIFF_PAIR_UNMERGED(p))
4208                return 0; /* unmerged is interesting */
4209
4210        /* deletion, addition, mode or type change
4211         * and rename are all interesting.
4212         */
4213        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4214            DIFF_PAIR_MODE_CHANGED(p) ||
4215            strcmp(one->path, two->path))
4216                return 0;
4217
4218        /* both are valid and point at the same path.  that is, we are
4219         * dealing with a change.
4220         */
4221        if (one->oid_valid && two->oid_valid &&
4222            !oidcmp(&one->oid, &two->oid) &&
4223            !one->dirty_submodule && !two->dirty_submodule)
4224                return 1; /* no change */
4225        if (!one->oid_valid && !two->oid_valid)
4226                return 1; /* both look at the same file on the filesystem. */
4227        return 0;
4228}
4229
4230static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4231{
4232        if (diff_unmodified_pair(p))
4233                return;
4234
4235        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4236            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4237                return; /* no tree diffs in patch format */
4238
4239        run_diff(p, o);
4240}
4241
4242static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4243                            struct diffstat_t *diffstat)
4244{
4245        if (diff_unmodified_pair(p))
4246                return;
4247
4248        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4249            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4250                return; /* no useful stat for tree diffs */
4251
4252        run_diffstat(p, o, diffstat);
4253}
4254
4255static void diff_flush_checkdiff(struct diff_filepair *p,
4256                struct diff_options *o)
4257{
4258        if (diff_unmodified_pair(p))
4259                return;
4260
4261        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4262            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4263                return; /* nothing to check in tree diffs */
4264
4265        run_checkdiff(p, o);
4266}
4267
4268int diff_queue_is_empty(void)
4269{
4270        struct diff_queue_struct *q = &diff_queued_diff;
4271        int i;
4272        for (i = 0; i < q->nr; i++)
4273                if (!diff_unmodified_pair(q->queue[i]))
4274                        return 0;
4275        return 1;
4276}
4277
4278#if DIFF_DEBUG
4279void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4280{
4281        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4282                x, one ? one : "",
4283                s->path,
4284                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4285                s->mode,
4286                s->oid_valid ? oid_to_hex(&s->oid) : "");
4287        fprintf(stderr, "queue[%d] %s size %lu\n",
4288                x, one ? one : "",
4289                s->size);
4290}
4291
4292void diff_debug_filepair(const struct diff_filepair *p, int i)
4293{
4294        diff_debug_filespec(p->one, i, "one");
4295        diff_debug_filespec(p->two, i, "two");
4296        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4297                p->score, p->status ? p->status : '?',
4298                p->one->rename_used, p->broken_pair);
4299}
4300
4301void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4302{
4303        int i;
4304        if (msg)
4305                fprintf(stderr, "%s\n", msg);
4306        fprintf(stderr, "q->nr = %d\n", q->nr);
4307        for (i = 0; i < q->nr; i++) {
4308                struct diff_filepair *p = q->queue[i];
4309                diff_debug_filepair(p, i);
4310        }
4311}
4312#endif
4313
4314static void diff_resolve_rename_copy(void)
4315{
4316        int i;
4317        struct diff_filepair *p;
4318        struct diff_queue_struct *q = &diff_queued_diff;
4319
4320        diff_debug_queue("resolve-rename-copy", q);
4321
4322        for (i = 0; i < q->nr; i++) {
4323                p = q->queue[i];
4324                p->status = 0; /* undecided */
4325                if (DIFF_PAIR_UNMERGED(p))
4326                        p->status = DIFF_STATUS_UNMERGED;
4327                else if (!DIFF_FILE_VALID(p->one))
4328                        p->status = DIFF_STATUS_ADDED;
4329                else if (!DIFF_FILE_VALID(p->two))
4330                        p->status = DIFF_STATUS_DELETED;
4331                else if (DIFF_PAIR_TYPE_CHANGED(p))
4332                        p->status = DIFF_STATUS_TYPE_CHANGED;
4333
4334                /* from this point on, we are dealing with a pair
4335                 * whose both sides are valid and of the same type, i.e.
4336                 * either in-place edit or rename/copy edit.
4337                 */
4338                else if (DIFF_PAIR_RENAME(p)) {
4339                        /*
4340                         * A rename might have re-connected a broken
4341                         * pair up, causing the pathnames to be the
4342                         * same again. If so, that's not a rename at
4343                         * all, just a modification..
4344                         *
4345                         * Otherwise, see if this source was used for
4346                         * multiple renames, in which case we decrement
4347                         * the count, and call it a copy.
4348                         */
4349                        if (!strcmp(p->one->path, p->two->path))
4350                                p->status = DIFF_STATUS_MODIFIED;
4351                        else if (--p->one->rename_used > 0)
4352                                p->status = DIFF_STATUS_COPIED;
4353                        else
4354                                p->status = DIFF_STATUS_RENAMED;
4355                }
4356                else if (oidcmp(&p->one->oid, &p->two->oid) ||
4357                         p->one->mode != p->two->mode ||
4358                         p->one->dirty_submodule ||
4359                         p->two->dirty_submodule ||
4360                         is_null_oid(&p->one->oid))
4361                        p->status = DIFF_STATUS_MODIFIED;
4362                else {
4363                        /* This is a "no-change" entry and should not
4364                         * happen anymore, but prepare for broken callers.
4365                         */
4366                        error("feeding unmodified %s to diffcore",
4367                              p->one->path);
4368                        p->status = DIFF_STATUS_UNKNOWN;
4369                }
4370        }
4371        diff_debug_queue("resolve-rename-copy done", q);
4372}
4373
4374static int check_pair_status(struct diff_filepair *p)
4375{
4376        switch (p->status) {
4377        case DIFF_STATUS_UNKNOWN:
4378                return 0;
4379        case 0:
4380                die("internal error in diff-resolve-rename-copy");
4381        default:
4382                return 1;
4383        }
4384}
4385
4386static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4387{
4388        int fmt = opt->output_format;
4389
4390        if (fmt & DIFF_FORMAT_CHECKDIFF)
4391                diff_flush_checkdiff(p, opt);
4392        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4393                diff_flush_raw(p, opt);
4394        else if (fmt & DIFF_FORMAT_NAME) {
4395                const char *name_a, *name_b;
4396                name_a = p->two->path;
4397                name_b = NULL;
4398                strip_prefix(opt->prefix_length, &name_a, &name_b);
4399                write_name_quoted(name_a, opt->file, opt->line_termination);
4400        }
4401}
4402
4403static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4404{
4405        if (fs->mode)
4406                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4407        else
4408                fprintf(file, " %s ", newdelete);
4409        write_name_quoted(fs->path, file, '\n');
4410}
4411
4412
4413static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4414                const char *line_prefix)
4415{
4416        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4417                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4418                        p->two->mode, show_name ? ' ' : '\n');
4419                if (show_name) {
4420                        write_name_quoted(p->two->path, file, '\n');
4421                }
4422        }
4423}
4424
4425static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4426                        const char *line_prefix)
4427{
4428        char *names = pprint_rename(p->one->path, p->two->path);
4429
4430        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4431        free(names);
4432        show_mode_change(file, p, 0, line_prefix);
4433}
4434
4435static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4436{
4437        FILE *file = opt->file;
4438        const char *line_prefix = diff_line_prefix(opt);
4439
4440        switch(p->status) {
4441        case DIFF_STATUS_DELETED:
4442                fputs(line_prefix, file);
4443                show_file_mode_name(file, "delete", p->one);
4444                break;
4445        case DIFF_STATUS_ADDED:
4446                fputs(line_prefix, file);
4447                show_file_mode_name(file, "create", p->two);
4448                break;
4449        case DIFF_STATUS_COPIED:
4450                fputs(line_prefix, file);
4451                show_rename_copy(file, "copy", p, line_prefix);
4452                break;
4453        case DIFF_STATUS_RENAMED:
4454                fputs(line_prefix, file);
4455                show_rename_copy(file, "rename", p, line_prefix);
4456                break;
4457        default:
4458                if (p->score) {
4459                        fprintf(file, "%s rewrite ", line_prefix);
4460                        write_name_quoted(p->two->path, file, ' ');
4461                        fprintf(file, "(%d%%)\n", similarity_index(p));
4462                }
4463                show_mode_change(file, p, !p->score, line_prefix);
4464                break;
4465        }
4466}
4467
4468struct patch_id_t {
4469        git_SHA_CTX *ctx;
4470        int patchlen;
4471};
4472
4473static int remove_space(char *line, int len)
4474{
4475        int i;
4476        char *dst = line;
4477        unsigned char c;
4478
4479        for (i = 0; i < len; i++)
4480                if (!isspace((c = line[i])))
4481                        *dst++ = c;
4482
4483        return dst - line;
4484}
4485
4486static void patch_id_consume(void *priv, char *line, unsigned long len)
4487{
4488        struct patch_id_t *data = priv;
4489        int new_len;
4490
4491        /* Ignore line numbers when computing the SHA1 of the patch */
4492        if (starts_with(line, "@@ -"))
4493                return;
4494
4495        new_len = remove_space(line, len);
4496
4497        git_SHA1_Update(data->ctx, line, new_len);
4498        data->patchlen += new_len;
4499}
4500
4501/* returns 0 upon success, and writes result into sha1 */
4502static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
4503{
4504        struct diff_queue_struct *q = &diff_queued_diff;
4505        int i;
4506        git_SHA_CTX ctx;
4507        struct patch_id_t data;
4508        char buffer[PATH_MAX * 4 + 20];
4509
4510        git_SHA1_Init(&ctx);
4511        memset(&data, 0, sizeof(struct patch_id_t));
4512        data.ctx = &ctx;
4513
4514        for (i = 0; i < q->nr; i++) {
4515                xpparam_t xpp;
4516                xdemitconf_t xecfg;
4517                mmfile_t mf1, mf2;
4518                struct diff_filepair *p = q->queue[i];
4519                int len1, len2;
4520
4521                memset(&xpp, 0, sizeof(xpp));
4522                memset(&xecfg, 0, sizeof(xecfg));
4523                if (p->status == 0)
4524                        return error("internal diff status error");
4525                if (p->status == DIFF_STATUS_UNKNOWN)
4526                        continue;
4527                if (diff_unmodified_pair(p))
4528                        continue;
4529                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4530                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4531                        continue;
4532                if (DIFF_PAIR_UNMERGED(p))
4533                        continue;
4534
4535                diff_fill_sha1_info(p->one);
4536                diff_fill_sha1_info(p->two);
4537
4538                len1 = remove_space(p->one->path, strlen(p->one->path));
4539                len2 = remove_space(p->two->path, strlen(p->two->path));
4540                if (p->one->mode == 0)
4541                        len1 = snprintf(buffer, sizeof(buffer),
4542                                        "diff--gita/%.*sb/%.*s"
4543                                        "newfilemode%06o"
4544                                        "---/dev/null"
4545                                        "+++b/%.*s",
4546                                        len1, p->one->path,
4547                                        len2, p->two->path,
4548                                        p->two->mode,
4549                                        len2, p->two->path);
4550                else if (p->two->mode == 0)
4551                        len1 = snprintf(buffer, sizeof(buffer),
4552                                        "diff--gita/%.*sb/%.*s"
4553                                        "deletedfilemode%06o"
4554                                        "---a/%.*s"
4555                                        "+++/dev/null",
4556                                        len1, p->one->path,
4557                                        len2, p->two->path,
4558                                        p->one->mode,
4559                                        len1, p->one->path);
4560                else
4561                        len1 = snprintf(buffer, sizeof(buffer),
4562                                        "diff--gita/%.*sb/%.*s"
4563                                        "---a/%.*s"
4564                                        "+++b/%.*s",
4565                                        len1, p->one->path,
4566                                        len2, p->two->path,
4567                                        len1, p->one->path,
4568                                        len2, p->two->path);
4569                git_SHA1_Update(&ctx, buffer, len1);
4570
4571                if (diff_header_only)
4572                        continue;
4573
4574                if (fill_mmfile(&mf1, p->one) < 0 ||
4575                    fill_mmfile(&mf2, p->two) < 0)
4576                        return error("unable to read files to diff");
4577
4578                if (diff_filespec_is_binary(p->one) ||
4579                    diff_filespec_is_binary(p->two)) {
4580                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
4581                                        40);
4582                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
4583                                        40);
4584                        continue;
4585                }
4586
4587                xpp.flags = 0;
4588                xecfg.ctxlen = 3;
4589                xecfg.flags = 0;
4590                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4591                                  &xpp, &xecfg))
4592                        return error("unable to generate patch-id diff for %s",
4593                                     p->one->path);
4594        }
4595
4596        git_SHA1_Final(sha1, &ctx);
4597        return 0;
4598}
4599
4600int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
4601{
4602        struct diff_queue_struct *q = &diff_queued_diff;
4603        int i;
4604        int result = diff_get_patch_id(options, sha1, diff_header_only);
4605
4606        for (i = 0; i < q->nr; i++)
4607                diff_free_filepair(q->queue[i]);
4608
4609        free(q->queue);
4610        DIFF_QUEUE_CLEAR(q);
4611
4612        return result;
4613}
4614
4615static int is_summary_empty(const struct diff_queue_struct *q)
4616{
4617        int i;
4618
4619        for (i = 0; i < q->nr; i++) {
4620                const struct diff_filepair *p = q->queue[i];
4621
4622                switch (p->status) {
4623                case DIFF_STATUS_DELETED:
4624                case DIFF_STATUS_ADDED:
4625                case DIFF_STATUS_COPIED:
4626                case DIFF_STATUS_RENAMED:
4627                        return 0;
4628                default:
4629                        if (p->score)
4630                                return 0;
4631                        if (p->one->mode && p->two->mode &&
4632                            p->one->mode != p->two->mode)
4633                                return 0;
4634                        break;
4635                }
4636        }
4637        return 1;
4638}
4639
4640static const char rename_limit_warning[] =
4641"inexact rename detection was skipped due to too many files.";
4642
4643static const char degrade_cc_to_c_warning[] =
4644"only found copies from modified paths due to too many files.";
4645
4646static const char rename_limit_advice[] =
4647"you may want to set your %s variable to at least "
4648"%d and retry the command.";
4649
4650void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4651{
4652        if (degraded_cc)
4653                warning(degrade_cc_to_c_warning);
4654        else if (needed)
4655                warning(rename_limit_warning);
4656        else
4657                return;
4658        if (0 < needed && needed < 32767)
4659                warning(rename_limit_advice, varname, needed);
4660}
4661
4662void diff_flush(struct diff_options *options)
4663{
4664        struct diff_queue_struct *q = &diff_queued_diff;
4665        int i, output_format = options->output_format;
4666        int separator = 0;
4667        int dirstat_by_line = 0;
4668
4669        /*
4670         * Order: raw, stat, summary, patch
4671         * or:    name/name-status/checkdiff (other bits clear)
4672         */
4673        if (!q->nr)
4674                goto free_queue;
4675
4676        if (output_format & (DIFF_FORMAT_RAW |
4677                             DIFF_FORMAT_NAME |
4678                             DIFF_FORMAT_NAME_STATUS |
4679                             DIFF_FORMAT_CHECKDIFF)) {
4680                for (i = 0; i < q->nr; i++) {
4681                        struct diff_filepair *p = q->queue[i];
4682                        if (check_pair_status(p))
4683                                flush_one_pair(p, options);
4684                }
4685                separator++;
4686        }
4687
4688        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4689                dirstat_by_line = 1;
4690
4691        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4692            dirstat_by_line) {
4693                struct diffstat_t diffstat;
4694
4695                memset(&diffstat, 0, sizeof(struct diffstat_t));
4696                for (i = 0; i < q->nr; i++) {
4697                        struct diff_filepair *p = q->queue[i];
4698                        if (check_pair_status(p))
4699                                diff_flush_stat(p, options, &diffstat);
4700                }
4701                if (output_format & DIFF_FORMAT_NUMSTAT)
4702                        show_numstat(&diffstat, options);
4703                if (output_format & DIFF_FORMAT_DIFFSTAT)
4704                        show_stats(&diffstat, options);
4705                if (output_format & DIFF_FORMAT_SHORTSTAT)
4706                        show_shortstats(&diffstat, options);
4707                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4708                        show_dirstat_by_line(&diffstat, options);
4709                free_diffstat_info(&diffstat);
4710                separator++;
4711        }
4712        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4713                show_dirstat(options);
4714
4715        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4716                for (i = 0; i < q->nr; i++) {
4717                        diff_summary(options, q->queue[i]);
4718                }
4719                separator++;
4720        }
4721
4722        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4723            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4724            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4725                /*
4726                 * run diff_flush_patch for the exit status. setting
4727                 * options->file to /dev/null should be safe, because we
4728                 * aren't supposed to produce any output anyway.
4729                 */
4730                if (options->close_file)
4731                        fclose(options->file);
4732                options->file = fopen("/dev/null", "w");
4733                if (!options->file)
4734                        die_errno("Could not open /dev/null");
4735                options->close_file = 1;
4736                for (i = 0; i < q->nr; i++) {
4737                        struct diff_filepair *p = q->queue[i];
4738                        if (check_pair_status(p))
4739                                diff_flush_patch(p, options);
4740                        if (options->found_changes)
4741                                break;
4742                }
4743        }
4744
4745        if (output_format & DIFF_FORMAT_PATCH) {
4746                if (separator) {
4747                        fprintf(options->file, "%s%c",
4748                                diff_line_prefix(options),
4749                                options->line_termination);
4750                        if (options->stat_sep) {
4751                                /* attach patch instead of inline */
4752                                fputs(options->stat_sep, options->file);
4753                        }
4754                }
4755
4756                for (i = 0; i < q->nr; i++) {
4757                        struct diff_filepair *p = q->queue[i];
4758                        if (check_pair_status(p))
4759                                diff_flush_patch(p, options);
4760                }
4761        }
4762
4763        if (output_format & DIFF_FORMAT_CALLBACK)
4764                options->format_callback(q, options, options->format_callback_data);
4765
4766        for (i = 0; i < q->nr; i++)
4767                diff_free_filepair(q->queue[i]);
4768free_queue:
4769        free(q->queue);
4770        DIFF_QUEUE_CLEAR(q);
4771        if (options->close_file)
4772                fclose(options->file);
4773
4774        /*
4775         * Report the content-level differences with HAS_CHANGES;
4776         * diff_addremove/diff_change does not set the bit when
4777         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4778         */
4779        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4780                if (options->found_changes)
4781                        DIFF_OPT_SET(options, HAS_CHANGES);
4782                else
4783                        DIFF_OPT_CLR(options, HAS_CHANGES);
4784        }
4785}
4786
4787static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4788{
4789        return (((p->status == DIFF_STATUS_MODIFIED) &&
4790                 ((p->score &&
4791                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4792                  (!p->score &&
4793                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4794                ((p->status != DIFF_STATUS_MODIFIED) &&
4795                 filter_bit_tst(p->status, options)));
4796}
4797
4798static void diffcore_apply_filter(struct diff_options *options)
4799{
4800        int i;
4801        struct diff_queue_struct *q = &diff_queued_diff;
4802        struct diff_queue_struct outq;
4803
4804        DIFF_QUEUE_CLEAR(&outq);
4805
4806        if (!options->filter)
4807                return;
4808
4809        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4810                int found;
4811                for (i = found = 0; !found && i < q->nr; i++) {
4812                        if (match_filter(options, q->queue[i]))
4813                                found++;
4814                }
4815                if (found)
4816                        return;
4817
4818                /* otherwise we will clear the whole queue
4819                 * by copying the empty outq at the end of this
4820                 * function, but first clear the current entries
4821                 * in the queue.
4822                 */
4823                for (i = 0; i < q->nr; i++)
4824                        diff_free_filepair(q->queue[i]);
4825        }
4826        else {
4827                /* Only the matching ones */
4828                for (i = 0; i < q->nr; i++) {
4829                        struct diff_filepair *p = q->queue[i];
4830                        if (match_filter(options, p))
4831                                diff_q(&outq, p);
4832                        else
4833                                diff_free_filepair(p);
4834                }
4835        }
4836        free(q->queue);
4837        *q = outq;
4838}
4839
4840/* Check whether two filespecs with the same mode and size are identical */
4841static int diff_filespec_is_identical(struct diff_filespec *one,
4842                                      struct diff_filespec *two)
4843{
4844        if (S_ISGITLINK(one->mode))
4845                return 0;
4846        if (diff_populate_filespec(one, 0))
4847                return 0;
4848        if (diff_populate_filespec(two, 0))
4849                return 0;
4850        return !memcmp(one->data, two->data, one->size);
4851}
4852
4853static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
4854{
4855        if (p->done_skip_stat_unmatch)
4856                return p->skip_stat_unmatch_result;
4857
4858        p->done_skip_stat_unmatch = 1;
4859        p->skip_stat_unmatch_result = 0;
4860        /*
4861         * 1. Entries that come from stat info dirtiness
4862         *    always have both sides (iow, not create/delete),
4863         *    one side of the object name is unknown, with
4864         *    the same mode and size.  Keep the ones that
4865         *    do not match these criteria.  They have real
4866         *    differences.
4867         *
4868         * 2. At this point, the file is known to be modified,
4869         *    with the same mode and size, and the object
4870         *    name of one side is unknown.  Need to inspect
4871         *    the identical contents.
4872         */
4873        if (!DIFF_FILE_VALID(p->one) || /* (1) */
4874            !DIFF_FILE_VALID(p->two) ||
4875            (p->one->oid_valid && p->two->oid_valid) ||
4876            (p->one->mode != p->two->mode) ||
4877            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
4878            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
4879            (p->one->size != p->two->size) ||
4880            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4881                p->skip_stat_unmatch_result = 1;
4882        return p->skip_stat_unmatch_result;
4883}
4884
4885static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4886{
4887        int i;
4888        struct diff_queue_struct *q = &diff_queued_diff;
4889        struct diff_queue_struct outq;
4890        DIFF_QUEUE_CLEAR(&outq);
4891
4892        for (i = 0; i < q->nr; i++) {
4893                struct diff_filepair *p = q->queue[i];
4894
4895                if (diff_filespec_check_stat_unmatch(p))
4896                        diff_q(&outq, p);
4897                else {
4898                        /*
4899                         * The caller can subtract 1 from skip_stat_unmatch
4900                         * to determine how many paths were dirty only
4901                         * due to stat info mismatch.
4902                         */
4903                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4904                                diffopt->skip_stat_unmatch++;
4905                        diff_free_filepair(p);
4906                }
4907        }
4908        free(q->queue);
4909        *q = outq;
4910}
4911
4912static int diffnamecmp(const void *a_, const void *b_)
4913{
4914        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4915        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4916        const char *name_a, *name_b;
4917
4918        name_a = a->one ? a->one->path : a->two->path;
4919        name_b = b->one ? b->one->path : b->two->path;
4920        return strcmp(name_a, name_b);
4921}
4922
4923void diffcore_fix_diff_index(struct diff_options *options)
4924{
4925        struct diff_queue_struct *q = &diff_queued_diff;
4926        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4927}
4928
4929void diffcore_std(struct diff_options *options)
4930{
4931        /* NOTE please keep the following in sync with diff_tree_combined() */
4932        if (options->skip_stat_unmatch)
4933                diffcore_skip_stat_unmatch(options);
4934        if (!options->found_follow) {
4935                /* See try_to_follow_renames() in tree-diff.c */
4936                if (options->break_opt != -1)
4937                        diffcore_break(options->break_opt);
4938                if (options->detect_rename)
4939                        diffcore_rename(options);
4940                if (options->break_opt != -1)
4941                        diffcore_merge_broken();
4942        }
4943        if (options->pickaxe)
4944                diffcore_pickaxe(options);
4945        if (options->orderfile)
4946                diffcore_order(options->orderfile);
4947        if (!options->found_follow)
4948                /* See try_to_follow_renames() in tree-diff.c */
4949                diff_resolve_rename_copy();
4950        diffcore_apply_filter(options);
4951
4952        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4953                DIFF_OPT_SET(options, HAS_CHANGES);
4954        else
4955                DIFF_OPT_CLR(options, HAS_CHANGES);
4956
4957        options->found_follow = 0;
4958}
4959
4960int diff_result_code(struct diff_options *opt, int status)
4961{
4962        int result = 0;
4963
4964        diff_warn_rename_limit("diff.renameLimit",
4965                               opt->needed_rename_limit,
4966                               opt->degraded_cc_to_c);
4967        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4968            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4969                return status;
4970        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4971            DIFF_OPT_TST(opt, HAS_CHANGES))
4972                result |= 01;
4973        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4974            DIFF_OPT_TST(opt, CHECK_FAILED))
4975                result |= 02;
4976        return result;
4977}
4978
4979int diff_can_quit_early(struct diff_options *opt)
4980{
4981        return (DIFF_OPT_TST(opt, QUICK) &&
4982                !opt->filter &&
4983                DIFF_OPT_TST(opt, HAS_CHANGES));
4984}
4985
4986/*
4987 * Shall changes to this submodule be ignored?
4988 *
4989 * Submodule changes can be configured to be ignored separately for each path,
4990 * but that configuration can be overridden from the command line.
4991 */
4992static int is_submodule_ignored(const char *path, struct diff_options *options)
4993{
4994        int ignored = 0;
4995        unsigned orig_flags = options->flags;
4996        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4997                set_diffopt_flags_from_submodule_config(options, path);
4998        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4999                ignored = 1;
5000        options->flags = orig_flags;
5001        return ignored;
5002}
5003
5004void diff_addremove(struct diff_options *options,
5005                    int addremove, unsigned mode,
5006                    const unsigned char *sha1,
5007                    int sha1_valid,
5008                    const char *concatpath, unsigned dirty_submodule)
5009{
5010        struct diff_filespec *one, *two;
5011
5012        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
5013                return;
5014
5015        /* This may look odd, but it is a preparation for
5016         * feeding "there are unchanged files which should
5017         * not produce diffs, but when you are doing copy
5018         * detection you would need them, so here they are"
5019         * entries to the diff-core.  They will be prefixed
5020         * with something like '=' or '*' (I haven't decided
5021         * which but should not make any difference).
5022         * Feeding the same new and old to diff_change()
5023         * also has the same effect.
5024         * Before the final output happens, they are pruned after
5025         * merged into rename/copy pairs as appropriate.
5026         */
5027        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5028                addremove = (addremove == '+' ? '-' :
5029                             addremove == '-' ? '+' : addremove);
5030
5031        if (options->prefix &&
5032            strncmp(concatpath, options->prefix, options->prefix_length))
5033                return;
5034
5035        one = alloc_filespec(concatpath);
5036        two = alloc_filespec(concatpath);
5037
5038        if (addremove != '+')
5039                fill_filespec(one, sha1, sha1_valid, mode);
5040        if (addremove != '-') {
5041                fill_filespec(two, sha1, sha1_valid, mode);
5042                two->dirty_submodule = dirty_submodule;
5043        }
5044
5045        diff_queue(&diff_queued_diff, one, two);
5046        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5047                DIFF_OPT_SET(options, HAS_CHANGES);
5048}
5049
5050void diff_change(struct diff_options *options,
5051                 unsigned old_mode, unsigned new_mode,
5052                 const unsigned char *old_sha1,
5053                 const unsigned char *new_sha1,
5054                 int old_sha1_valid, int new_sha1_valid,
5055                 const char *concatpath,
5056                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5057{
5058        struct diff_filespec *one, *two;
5059        struct diff_filepair *p;
5060
5061        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5062            is_submodule_ignored(concatpath, options))
5063                return;
5064
5065        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5066                unsigned tmp;
5067                const unsigned char *tmp_c;
5068                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
5069                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
5070                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
5071                        new_sha1_valid = tmp;
5072                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
5073                        new_dirty_submodule = tmp;
5074        }
5075
5076        if (options->prefix &&
5077            strncmp(concatpath, options->prefix, options->prefix_length))
5078                return;
5079
5080        one = alloc_filespec(concatpath);
5081        two = alloc_filespec(concatpath);
5082        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
5083        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
5084        one->dirty_submodule = old_dirty_submodule;
5085        two->dirty_submodule = new_dirty_submodule;
5086        p = diff_queue(&diff_queued_diff, one, two);
5087
5088        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5089                return;
5090
5091        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5092            !diff_filespec_check_stat_unmatch(p))
5093                return;
5094
5095        DIFF_OPT_SET(options, HAS_CHANGES);
5096}
5097
5098struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5099{
5100        struct diff_filepair *pair;
5101        struct diff_filespec *one, *two;
5102
5103        if (options->prefix &&
5104            strncmp(path, options->prefix, options->prefix_length))
5105                return NULL;
5106
5107        one = alloc_filespec(path);
5108        two = alloc_filespec(path);
5109        pair = diff_queue(&diff_queued_diff, one, two);
5110        pair->is_unmerged = 1;
5111        return pair;
5112}
5113
5114static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5115                size_t *outsize)
5116{
5117        struct diff_tempfile *temp;
5118        const char *argv[3];
5119        const char **arg = argv;
5120        struct child_process child = CHILD_PROCESS_INIT;
5121        struct strbuf buf = STRBUF_INIT;
5122        int err = 0;
5123
5124        temp = prepare_temp_file(spec->path, spec);
5125        *arg++ = pgm;
5126        *arg++ = temp->name;
5127        *arg = NULL;
5128
5129        child.use_shell = 1;
5130        child.argv = argv;
5131        child.out = -1;
5132        if (start_command(&child)) {
5133                remove_tempfile();
5134                return NULL;
5135        }
5136
5137        if (strbuf_read(&buf, child.out, 0) < 0)
5138                err = error("error reading from textconv command '%s'", pgm);
5139        close(child.out);
5140
5141        if (finish_command(&child) || err) {
5142                strbuf_release(&buf);
5143                remove_tempfile();
5144                return NULL;
5145        }
5146        remove_tempfile();
5147
5148        return strbuf_detach(&buf, outsize);
5149}
5150
5151size_t fill_textconv(struct userdiff_driver *driver,
5152                     struct diff_filespec *df,
5153                     char **outbuf)
5154{
5155        size_t size;
5156
5157        if (!driver) {
5158                if (!DIFF_FILE_VALID(df)) {
5159                        *outbuf = "";
5160                        return 0;
5161                }
5162                if (diff_populate_filespec(df, 0))
5163                        die("unable to read files to diff");
5164                *outbuf = df->data;
5165                return df->size;
5166        }
5167
5168        if (!driver->textconv)
5169                die("BUG: fill_textconv called with non-textconv driver");
5170
5171        if (driver->textconv_cache && df->oid_valid) {
5172                *outbuf = notes_cache_get(driver->textconv_cache,
5173                                          df->oid.hash,
5174                                          &size);
5175                if (*outbuf)
5176                        return size;
5177        }
5178
5179        *outbuf = run_textconv(driver->textconv, df, &size);
5180        if (!*outbuf)
5181                die("unable to read files to diff");
5182
5183        if (driver->textconv_cache && df->oid_valid) {
5184                /* ignore errors, as we might be in a readonly repository */
5185                notes_cache_put(driver->textconv_cache, df->oid.hash, *outbuf,
5186                                size);
5187                /*
5188                 * we could save up changes and flush them all at the end,
5189                 * but we would need an extra call after all diffing is done.
5190                 * Since generating a cache entry is the slow path anyway,
5191                 * this extra overhead probably isn't a big deal.
5192                 */
5193                notes_cache_write(driver->textconv_cache);
5194        }
5195
5196        return size;
5197}
5198
5199void setup_diff_pager(struct diff_options *opt)
5200{
5201        /*
5202         * If the user asked for our exit code, then either they want --quiet
5203         * or --exit-code. We should definitely not bother with a pager in the
5204         * former case, as we will generate no output. Since we still properly
5205         * report our exit code even when a pager is run, we _could_ run a
5206         * pager with --exit-code. But since we have not done so historically,
5207         * and because it is easy to find people oneline advising "git diff
5208         * --exit-code" in hooks and other scripts, we do not do so.
5209         */
5210        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5211            check_pager_config("diff") != 0)
5212                setup_pager();
5213}