diff.con commit Merge branch 'js/git-gui-commit-gpgsign' (e6a51af)
   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_compaction_heuristic; /* experimental */
  31static int diff_rename_limit_default = 400;
  32static int diff_suppress_blank_empty;
  33static int diff_use_color_default = -1;
  34static int diff_context_default = 3;
  35static const char *diff_word_regex_cfg;
  36static const char *external_diff_cmd_cfg;
  37static const char *diff_order_file_cfg;
  38int diff_auto_refresh_index = 1;
  39static int diff_mnemonic_prefix;
  40static int diff_no_prefix;
  41static int diff_stat_graph_width;
  42static int diff_dirstat_permille_default = 30;
  43static struct diff_options default_diff_options;
  44static long diff_algorithm;
  45
  46static char diff_colors[][COLOR_MAXLEN] = {
  47        GIT_COLOR_RESET,
  48        GIT_COLOR_NORMAL,       /* CONTEXT */
  49        GIT_COLOR_BOLD,         /* METAINFO */
  50        GIT_COLOR_CYAN,         /* FRAGINFO */
  51        GIT_COLOR_RED,          /* OLD */
  52        GIT_COLOR_GREEN,        /* NEW */
  53        GIT_COLOR_YELLOW,       /* COMMIT */
  54        GIT_COLOR_BG_RED,       /* WHITESPACE */
  55        GIT_COLOR_NORMAL,       /* FUNCINFO */
  56};
  57
  58static int parse_diff_color_slot(const char *var)
  59{
  60        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
  61                return DIFF_CONTEXT;
  62        if (!strcasecmp(var, "meta"))
  63                return DIFF_METAINFO;
  64        if (!strcasecmp(var, "frag"))
  65                return DIFF_FRAGINFO;
  66        if (!strcasecmp(var, "old"))
  67                return DIFF_FILE_OLD;
  68        if (!strcasecmp(var, "new"))
  69                return DIFF_FILE_NEW;
  70        if (!strcasecmp(var, "commit"))
  71                return DIFF_COMMIT;
  72        if (!strcasecmp(var, "whitespace"))
  73                return DIFF_WHITESPACE;
  74        if (!strcasecmp(var, "func"))
  75                return DIFF_FUNCINFO;
  76        return -1;
  77}
  78
  79static int parse_dirstat_params(struct diff_options *options, const char *params_string,
  80                                struct strbuf *errmsg)
  81{
  82        char *params_copy = xstrdup(params_string);
  83        struct string_list params = STRING_LIST_INIT_NODUP;
  84        int ret = 0;
  85        int i;
  86
  87        if (*params_copy)
  88                string_list_split_in_place(&params, params_copy, ',', -1);
  89        for (i = 0; i < params.nr; i++) {
  90                const char *p = params.items[i].string;
  91                if (!strcmp(p, "changes")) {
  92                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  93                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  94                } else if (!strcmp(p, "lines")) {
  95                        DIFF_OPT_SET(options, DIRSTAT_BY_LINE);
  96                        DIFF_OPT_CLR(options, DIRSTAT_BY_FILE);
  97                } else if (!strcmp(p, "files")) {
  98                        DIFF_OPT_CLR(options, DIRSTAT_BY_LINE);
  99                        DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
 100                } else if (!strcmp(p, "noncumulative")) {
 101                        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
 102                } else if (!strcmp(p, "cumulative")) {
 103                        DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
 104                } else if (isdigit(*p)) {
 105                        char *end;
 106                        int permille = strtoul(p, &end, 10) * 10;
 107                        if (*end == '.' && isdigit(*++end)) {
 108                                /* only use first digit */
 109                                permille += *end - '0';
 110                                /* .. and ignore any further digits */
 111                                while (isdigit(*++end))
 112                                        ; /* nothing */
 113                        }
 114                        if (!*end)
 115                                options->dirstat_permille = permille;
 116                        else {
 117                                strbuf_addf(errmsg, _("  Failed to parse dirstat cut-off percentage '%s'\n"),
 118                                            p);
 119                                ret++;
 120                        }
 121                } else {
 122                        strbuf_addf(errmsg, _("  Unknown dirstat parameter '%s'\n"), p);
 123                        ret++;
 124                }
 125
 126        }
 127        string_list_clear(&params, 0);
 128        free(params_copy);
 129        return ret;
 130}
 131
 132static int parse_submodule_params(struct diff_options *options, const char *value)
 133{
 134        if (!strcmp(value, "log"))
 135                options->submodule_format = DIFF_SUBMODULE_LOG;
 136        else if (!strcmp(value, "short"))
 137                options->submodule_format = DIFF_SUBMODULE_SHORT;
 138        else if (!strcmp(value, "diff"))
 139                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
 140        else
 141                return -1;
 142        return 0;
 143}
 144
 145static int git_config_rename(const char *var, const char *value)
 146{
 147        if (!value)
 148                return DIFF_DETECT_RENAME;
 149        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
 150                return  DIFF_DETECT_COPY;
 151        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
 152}
 153
 154long parse_algorithm_value(const char *value)
 155{
 156        if (!value)
 157                return -1;
 158        else if (!strcasecmp(value, "myers") || !strcasecmp(value, "default"))
 159                return 0;
 160        else if (!strcasecmp(value, "minimal"))
 161                return XDF_NEED_MINIMAL;
 162        else if (!strcasecmp(value, "patience"))
 163                return XDF_PATIENCE_DIFF;
 164        else if (!strcasecmp(value, "histogram"))
 165                return XDF_HISTOGRAM_DIFF;
 166        return -1;
 167}
 168
 169/*
 170 * These are to give UI layer defaults.
 171 * The core-level commands such as git-diff-files should
 172 * never be affected by the setting of diff.renames
 173 * the user happens to have in the configuration file.
 174 */
 175void init_diff_ui_defaults(void)
 176{
 177        diff_detect_rename_default = 1;
 178}
 179
 180int git_diff_ui_config(const char *var, const char *value, void *cb)
 181{
 182        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 183                diff_use_color_default = git_config_colorbool(var, value);
 184                return 0;
 185        }
 186        if (!strcmp(var, "diff.context")) {
 187                diff_context_default = git_config_int(var, value);
 188                if (diff_context_default < 0)
 189                        return -1;
 190                return 0;
 191        }
 192        if (!strcmp(var, "diff.renames")) {
 193                diff_detect_rename_default = git_config_rename(var, value);
 194                return 0;
 195        }
 196        if (!strcmp(var, "diff.compactionheuristic")) {
 197                diff_compaction_heuristic = git_config_bool(var, value);
 198                return 0;
 199        }
 200        if (!strcmp(var, "diff.autorefreshindex")) {
 201                diff_auto_refresh_index = git_config_bool(var, value);
 202                return 0;
 203        }
 204        if (!strcmp(var, "diff.mnemonicprefix")) {
 205                diff_mnemonic_prefix = git_config_bool(var, value);
 206                return 0;
 207        }
 208        if (!strcmp(var, "diff.noprefix")) {
 209                diff_no_prefix = git_config_bool(var, value);
 210                return 0;
 211        }
 212        if (!strcmp(var, "diff.statgraphwidth")) {
 213                diff_stat_graph_width = git_config_int(var, value);
 214                return 0;
 215        }
 216        if (!strcmp(var, "diff.external"))
 217                return git_config_string(&external_diff_cmd_cfg, var, value);
 218        if (!strcmp(var, "diff.wordregex"))
 219                return git_config_string(&diff_word_regex_cfg, var, value);
 220        if (!strcmp(var, "diff.orderfile"))
 221                return git_config_pathname(&diff_order_file_cfg, var, value);
 222
 223        if (!strcmp(var, "diff.ignoresubmodules"))
 224                handle_ignore_submodules_arg(&default_diff_options, value);
 225
 226        if (!strcmp(var, "diff.submodule")) {
 227                if (parse_submodule_params(&default_diff_options, value))
 228                        warning(_("Unknown value for 'diff.submodule' config variable: '%s'"),
 229                                value);
 230                return 0;
 231        }
 232
 233        if (!strcmp(var, "diff.algorithm")) {
 234                diff_algorithm = parse_algorithm_value(value);
 235                if (diff_algorithm < 0)
 236                        return -1;
 237                return 0;
 238        }
 239
 240        if (git_color_config(var, value, cb) < 0)
 241                return -1;
 242
 243        return git_diff_basic_config(var, value, cb);
 244}
 245
 246int git_diff_basic_config(const char *var, const char *value, void *cb)
 247{
 248        const char *name;
 249
 250        if (!strcmp(var, "diff.renamelimit")) {
 251                diff_rename_limit_default = git_config_int(var, value);
 252                return 0;
 253        }
 254
 255        if (userdiff_config(var, value) < 0)
 256                return -1;
 257
 258        if (skip_prefix(var, "diff.color.", &name) ||
 259            skip_prefix(var, "color.diff.", &name)) {
 260                int slot = parse_diff_color_slot(name);
 261                if (slot < 0)
 262                        return 0;
 263                if (!value)
 264                        return config_error_nonbool(var);
 265                return color_parse(value, diff_colors[slot]);
 266        }
 267
 268        /* like GNU diff's --suppress-blank-empty option  */
 269        if (!strcmp(var, "diff.suppressblankempty") ||
 270                        /* for backwards compatibility */
 271                        !strcmp(var, "diff.suppress-blank-empty")) {
 272                diff_suppress_blank_empty = git_config_bool(var, value);
 273                return 0;
 274        }
 275
 276        if (!strcmp(var, "diff.dirstat")) {
 277                struct strbuf errmsg = STRBUF_INIT;
 278                default_diff_options.dirstat_permille = diff_dirstat_permille_default;
 279                if (parse_dirstat_params(&default_diff_options, value, &errmsg))
 280                        warning(_("Found errors in 'diff.dirstat' config variable:\n%s"),
 281                                errmsg.buf);
 282                strbuf_release(&errmsg);
 283                diff_dirstat_permille_default = default_diff_options.dirstat_permille;
 284                return 0;
 285        }
 286
 287        if (starts_with(var, "submodule."))
 288                return parse_submodule_config_option(var, value);
 289
 290        return git_default_config(var, value, cb);
 291}
 292
 293static char *quote_two(const char *one, const char *two)
 294{
 295        int need_one = quote_c_style(one, NULL, NULL, 1);
 296        int need_two = quote_c_style(two, NULL, NULL, 1);
 297        struct strbuf res = STRBUF_INIT;
 298
 299        if (need_one + need_two) {
 300                strbuf_addch(&res, '"');
 301                quote_c_style(one, &res, NULL, 1);
 302                quote_c_style(two, &res, NULL, 1);
 303                strbuf_addch(&res, '"');
 304        } else {
 305                strbuf_addstr(&res, one);
 306                strbuf_addstr(&res, two);
 307        }
 308        return strbuf_detach(&res, NULL);
 309}
 310
 311static const char *external_diff(void)
 312{
 313        static const char *external_diff_cmd = NULL;
 314        static int done_preparing = 0;
 315
 316        if (done_preparing)
 317                return external_diff_cmd;
 318        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 319        if (!external_diff_cmd)
 320                external_diff_cmd = external_diff_cmd_cfg;
 321        done_preparing = 1;
 322        return external_diff_cmd;
 323}
 324
 325/*
 326 * Keep track of files used for diffing. Sometimes such an entry
 327 * refers to a temporary file, sometimes to an existing file, and
 328 * sometimes to "/dev/null".
 329 */
 330static struct diff_tempfile {
 331        /*
 332         * filename external diff should read from, or NULL if this
 333         * entry is currently not in use:
 334         */
 335        const char *name;
 336
 337        char hex[GIT_SHA1_HEXSZ + 1];
 338        char mode[10];
 339
 340        /*
 341         * If this diff_tempfile instance refers to a temporary file,
 342         * this tempfile object is used to manage its lifetime.
 343         */
 344        struct tempfile tempfile;
 345} diff_temp[2];
 346
 347typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 348
 349struct emit_callback {
 350        int color_diff;
 351        unsigned ws_rule;
 352        int blank_at_eof_in_preimage;
 353        int blank_at_eof_in_postimage;
 354        int lno_in_preimage;
 355        int lno_in_postimage;
 356        sane_truncate_fn truncate;
 357        const char **label_path;
 358        struct diff_words_data *diff_words;
 359        struct diff_options *opt;
 360        struct strbuf *header;
 361};
 362
 363static int count_lines(const char *data, int size)
 364{
 365        int count, ch, completely_empty = 1, nl_just_seen = 0;
 366        count = 0;
 367        while (0 < size--) {
 368                ch = *data++;
 369                if (ch == '\n') {
 370                        count++;
 371                        nl_just_seen = 1;
 372                        completely_empty = 0;
 373                }
 374                else {
 375                        nl_just_seen = 0;
 376                        completely_empty = 0;
 377                }
 378        }
 379        if (completely_empty)
 380                return 0;
 381        if (!nl_just_seen)
 382                count++; /* no trailing newline */
 383        return count;
 384}
 385
 386static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 387{
 388        if (!DIFF_FILE_VALID(one)) {
 389                mf->ptr = (char *)""; /* does not matter */
 390                mf->size = 0;
 391                return 0;
 392        }
 393        else if (diff_populate_filespec(one, 0))
 394                return -1;
 395
 396        mf->ptr = one->data;
 397        mf->size = one->size;
 398        return 0;
 399}
 400
 401/* like fill_mmfile, but only for size, so we can avoid retrieving blob */
 402static unsigned long diff_filespec_size(struct diff_filespec *one)
 403{
 404        if (!DIFF_FILE_VALID(one))
 405                return 0;
 406        diff_populate_filespec(one, CHECK_SIZE_ONLY);
 407        return one->size;
 408}
 409
 410static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 411{
 412        char *ptr = mf->ptr;
 413        long size = mf->size;
 414        int cnt = 0;
 415
 416        if (!size)
 417                return cnt;
 418        ptr += size - 1; /* pointing at the very end */
 419        if (*ptr != '\n')
 420                ; /* incomplete line */
 421        else
 422                ptr--; /* skip the last LF */
 423        while (mf->ptr < ptr) {
 424                char *prev_eol;
 425                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 426                        if (*prev_eol == '\n')
 427                                break;
 428                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 429                        break;
 430                cnt++;
 431                ptr = prev_eol - 1;
 432        }
 433        return cnt;
 434}
 435
 436static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 437                               struct emit_callback *ecbdata)
 438{
 439        int l1, l2, at;
 440        unsigned ws_rule = ecbdata->ws_rule;
 441        l1 = count_trailing_blank(mf1, ws_rule);
 442        l2 = count_trailing_blank(mf2, ws_rule);
 443        if (l2 <= l1) {
 444                ecbdata->blank_at_eof_in_preimage = 0;
 445                ecbdata->blank_at_eof_in_postimage = 0;
 446                return;
 447        }
 448        at = count_lines(mf1->ptr, mf1->size);
 449        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 450
 451        at = count_lines(mf2->ptr, mf2->size);
 452        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 453}
 454
 455static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 456                        int first, const char *line, int len)
 457{
 458        int has_trailing_newline, has_trailing_carriage_return;
 459        int nofirst;
 460        FILE *file = o->file;
 461
 462        fputs(diff_line_prefix(o), file);
 463
 464        if (len == 0) {
 465                has_trailing_newline = (first == '\n');
 466                has_trailing_carriage_return = (!has_trailing_newline &&
 467                                                (first == '\r'));
 468                nofirst = has_trailing_newline || has_trailing_carriage_return;
 469        } else {
 470                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 471                if (has_trailing_newline)
 472                        len--;
 473                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 474                if (has_trailing_carriage_return)
 475                        len--;
 476                nofirst = 0;
 477        }
 478
 479        if (len || !nofirst) {
 480                fputs(set, file);
 481                if (!nofirst)
 482                        fputc(first, file);
 483                fwrite(line, len, 1, file);
 484                fputs(reset, file);
 485        }
 486        if (has_trailing_carriage_return)
 487                fputc('\r', file);
 488        if (has_trailing_newline)
 489                fputc('\n', file);
 490}
 491
 492static void emit_line(struct diff_options *o, const char *set, const char *reset,
 493                      const char *line, int len)
 494{
 495        emit_line_0(o, set, reset, line[0], line+1, len-1);
 496}
 497
 498static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 499{
 500        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 501              ecbdata->blank_at_eof_in_preimage &&
 502              ecbdata->blank_at_eof_in_postimage &&
 503              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 504              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 505                return 0;
 506        return ws_blank_line(line, len, ecbdata->ws_rule);
 507}
 508
 509static void emit_line_checked(const char *reset,
 510                              struct emit_callback *ecbdata,
 511                              const char *line, int len,
 512                              enum color_diff color,
 513                              unsigned ws_error_highlight,
 514                              char sign)
 515{
 516        const char *set = diff_get_color(ecbdata->color_diff, color);
 517        const char *ws = NULL;
 518
 519        if (ecbdata->opt->ws_error_highlight & ws_error_highlight) {
 520                ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 521                if (!*ws)
 522                        ws = NULL;
 523        }
 524
 525        if (!ws)
 526                emit_line_0(ecbdata->opt, set, reset, sign, line, len);
 527        else if (sign == '+' && new_blank_line_at_eof(ecbdata, line, len))
 528                /* Blank line at EOF - paint '+' as well */
 529                emit_line_0(ecbdata->opt, ws, reset, sign, line, len);
 530        else {
 531                /* Emit just the prefix, then the rest. */
 532                emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
 533                ws_check_emit(line, len, ecbdata->ws_rule,
 534                              ecbdata->opt->file, set, reset, ws);
 535        }
 536}
 537
 538static void emit_add_line(const char *reset,
 539                          struct emit_callback *ecbdata,
 540                          const char *line, int len)
 541{
 542        emit_line_checked(reset, ecbdata, line, len,
 543                          DIFF_FILE_NEW, WSEH_NEW, '+');
 544}
 545
 546static void emit_del_line(const char *reset,
 547                          struct emit_callback *ecbdata,
 548                          const char *line, int len)
 549{
 550        emit_line_checked(reset, ecbdata, line, len,
 551                          DIFF_FILE_OLD, WSEH_OLD, '-');
 552}
 553
 554static void emit_context_line(const char *reset,
 555                              struct emit_callback *ecbdata,
 556                              const char *line, int len)
 557{
 558        emit_line_checked(reset, ecbdata, line, len,
 559                          DIFF_CONTEXT, WSEH_CONTEXT, ' ');
 560}
 561
 562static void emit_hunk_header(struct emit_callback *ecbdata,
 563                             const char *line, int len)
 564{
 565        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
 566        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 567        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 568        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 569        static const char atat[2] = { '@', '@' };
 570        const char *cp, *ep;
 571        struct strbuf msgbuf = STRBUF_INIT;
 572        int org_len = len;
 573        int i = 1;
 574
 575        /*
 576         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 577         * it always is at least 10 bytes long.
 578         */
 579        if (len < 10 ||
 580            memcmp(line, atat, 2) ||
 581            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 582                emit_line(ecbdata->opt, context, reset, line, len);
 583                return;
 584        }
 585        ep += 2; /* skip over @@ */
 586
 587        /* The hunk header in fraginfo color */
 588        strbuf_addstr(&msgbuf, frag);
 589        strbuf_add(&msgbuf, line, ep - line);
 590        strbuf_addstr(&msgbuf, reset);
 591
 592        /*
 593         * trailing "\r\n"
 594         */
 595        for ( ; i < 3; i++)
 596                if (line[len - i] == '\r' || line[len - i] == '\n')
 597                        len--;
 598
 599        /* blank before the func header */
 600        for (cp = ep; ep - line < len; ep++)
 601                if (*ep != ' ' && *ep != '\t')
 602                        break;
 603        if (ep != cp) {
 604                strbuf_addstr(&msgbuf, context);
 605                strbuf_add(&msgbuf, cp, ep - cp);
 606                strbuf_addstr(&msgbuf, reset);
 607        }
 608
 609        if (ep < line + len) {
 610                strbuf_addstr(&msgbuf, func);
 611                strbuf_add(&msgbuf, ep, line + len - ep);
 612                strbuf_addstr(&msgbuf, reset);
 613        }
 614
 615        strbuf_add(&msgbuf, line + len, org_len - len);
 616        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 617        strbuf_release(&msgbuf);
 618}
 619
 620static struct diff_tempfile *claim_diff_tempfile(void) {
 621        int i;
 622        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 623                if (!diff_temp[i].name)
 624                        return diff_temp + i;
 625        die("BUG: diff is failing to clean up its tempfiles");
 626}
 627
 628static void remove_tempfile(void)
 629{
 630        int i;
 631        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 632                if (is_tempfile_active(&diff_temp[i].tempfile))
 633                        delete_tempfile(&diff_temp[i].tempfile);
 634                diff_temp[i].name = NULL;
 635        }
 636}
 637
 638static void print_line_count(FILE *file, int count)
 639{
 640        switch (count) {
 641        case 0:
 642                fprintf(file, "0,0");
 643                break;
 644        case 1:
 645                fprintf(file, "1");
 646                break;
 647        default:
 648                fprintf(file, "1,%d", count);
 649                break;
 650        }
 651}
 652
 653static void emit_rewrite_lines(struct emit_callback *ecb,
 654                               int prefix, const char *data, int size)
 655{
 656        const char *endp = NULL;
 657        static const char *nneof = " No newline at end of file\n";
 658        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 659
 660        while (0 < size) {
 661                int len;
 662
 663                endp = memchr(data, '\n', size);
 664                len = endp ? (endp - data + 1) : size;
 665                if (prefix != '+') {
 666                        ecb->lno_in_preimage++;
 667                        emit_del_line(reset, ecb, data, len);
 668                } else {
 669                        ecb->lno_in_postimage++;
 670                        emit_add_line(reset, ecb, data, len);
 671                }
 672                size -= len;
 673                data += len;
 674        }
 675        if (!endp) {
 676                const char *context = diff_get_color(ecb->color_diff,
 677                                                     DIFF_CONTEXT);
 678                putc('\n', ecb->opt->file);
 679                emit_line_0(ecb->opt, context, reset, '\\',
 680                            nneof, strlen(nneof));
 681        }
 682}
 683
 684static void emit_rewrite_diff(const char *name_a,
 685                              const char *name_b,
 686                              struct diff_filespec *one,
 687                              struct diff_filespec *two,
 688                              struct userdiff_driver *textconv_one,
 689                              struct userdiff_driver *textconv_two,
 690                              struct diff_options *o)
 691{
 692        int lc_a, lc_b;
 693        const char *name_a_tab, *name_b_tab;
 694        const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
 695        const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
 696        const char *reset = diff_get_color(o->use_color, DIFF_RESET);
 697        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 698        const char *a_prefix, *b_prefix;
 699        char *data_one, *data_two;
 700        size_t size_one, size_two;
 701        struct emit_callback ecbdata;
 702        const char *line_prefix = diff_line_prefix(o);
 703
 704        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 705                a_prefix = o->b_prefix;
 706                b_prefix = o->a_prefix;
 707        } else {
 708                a_prefix = o->a_prefix;
 709                b_prefix = o->b_prefix;
 710        }
 711
 712        name_a += (*name_a == '/');
 713        name_b += (*name_b == '/');
 714        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 715        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 716
 717        strbuf_reset(&a_name);
 718        strbuf_reset(&b_name);
 719        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 720        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 721
 722        size_one = fill_textconv(textconv_one, one, &data_one);
 723        size_two = fill_textconv(textconv_two, two, &data_two);
 724
 725        memset(&ecbdata, 0, sizeof(ecbdata));
 726        ecbdata.color_diff = want_color(o->use_color);
 727        ecbdata.ws_rule = whitespace_rule(name_b);
 728        ecbdata.opt = o;
 729        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 730                mmfile_t mf1, mf2;
 731                mf1.ptr = (char *)data_one;
 732                mf2.ptr = (char *)data_two;
 733                mf1.size = size_one;
 734                mf2.size = size_two;
 735                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 736        }
 737        ecbdata.lno_in_preimage = 1;
 738        ecbdata.lno_in_postimage = 1;
 739
 740        lc_a = count_lines(data_one, size_one);
 741        lc_b = count_lines(data_two, size_two);
 742        fprintf(o->file,
 743                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 744                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 745                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 746                line_prefix, fraginfo);
 747        if (!o->irreversible_delete)
 748                print_line_count(o->file, lc_a);
 749        else
 750                fprintf(o->file, "?,?");
 751        fprintf(o->file, " +");
 752        print_line_count(o->file, lc_b);
 753        fprintf(o->file, " @@%s\n", reset);
 754        if (lc_a && !o->irreversible_delete)
 755                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 756        if (lc_b)
 757                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 758        if (textconv_one)
 759                free((char *)data_one);
 760        if (textconv_two)
 761                free((char *)data_two);
 762}
 763
 764struct diff_words_buffer {
 765        mmfile_t text;
 766        long alloc;
 767        struct diff_words_orig {
 768                const char *begin, *end;
 769        } *orig;
 770        int orig_nr, orig_alloc;
 771};
 772
 773static void diff_words_append(char *line, unsigned long len,
 774                struct diff_words_buffer *buffer)
 775{
 776        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 777        line++;
 778        len--;
 779        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 780        buffer->text.size += len;
 781        buffer->text.ptr[buffer->text.size] = '\0';
 782}
 783
 784struct diff_words_style_elem {
 785        const char *prefix;
 786        const char *suffix;
 787        const char *color; /* NULL; filled in by the setup code if
 788                            * color is enabled */
 789};
 790
 791struct diff_words_style {
 792        enum diff_words_type type;
 793        struct diff_words_style_elem new, old, ctx;
 794        const char *newline;
 795};
 796
 797static struct diff_words_style diff_words_styles[] = {
 798        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 799        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 800        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 801};
 802
 803struct diff_words_data {
 804        struct diff_words_buffer minus, plus;
 805        const char *current_plus;
 806        int last_minus;
 807        struct diff_options *opt;
 808        regex_t *word_regex;
 809        enum diff_words_type type;
 810        struct diff_words_style *style;
 811};
 812
 813static int fn_out_diff_words_write_helper(FILE *fp,
 814                                          struct diff_words_style_elem *st_el,
 815                                          const char *newline,
 816                                          size_t count, const char *buf,
 817                                          const char *line_prefix)
 818{
 819        int print = 0;
 820
 821        while (count) {
 822                char *p = memchr(buf, '\n', count);
 823                if (print)
 824                        fputs(line_prefix, fp);
 825                if (p != buf) {
 826                        if (st_el->color && fputs(st_el->color, fp) < 0)
 827                                return -1;
 828                        if (fputs(st_el->prefix, fp) < 0 ||
 829                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 830                            fputs(st_el->suffix, fp) < 0)
 831                                return -1;
 832                        if (st_el->color && *st_el->color
 833                            && fputs(GIT_COLOR_RESET, fp) < 0)
 834                                return -1;
 835                }
 836                if (!p)
 837                        return 0;
 838                if (fputs(newline, fp) < 0)
 839                        return -1;
 840                count -= p + 1 - buf;
 841                buf = p + 1;
 842                print = 1;
 843        }
 844        return 0;
 845}
 846
 847/*
 848 * '--color-words' algorithm can be described as:
 849 *
 850 *   1. collect a the minus/plus lines of a diff hunk, divided into
 851 *      minus-lines and plus-lines;
 852 *
 853 *   2. break both minus-lines and plus-lines into words and
 854 *      place them into two mmfile_t with one word for each line;
 855 *
 856 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 857 *
 858 * And for the common parts of the both file, we output the plus side text.
 859 * diff_words->current_plus is used to trace the current position of the plus file
 860 * which printed. diff_words->last_minus is used to trace the last minus word
 861 * printed.
 862 *
 863 * For '--graph' to work with '--color-words', we need to output the graph prefix
 864 * on each line of color words output. Generally, there are two conditions on
 865 * which we should output the prefix.
 866 *
 867 *   1. diff_words->last_minus == 0 &&
 868 *      diff_words->current_plus == diff_words->plus.text.ptr
 869 *
 870 *      that is: the plus text must start as a new line, and if there is no minus
 871 *      word printed, a graph prefix must be printed.
 872 *
 873 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 874 *      *(diff_words->current_plus - 1) == '\n'
 875 *
 876 *      that is: a graph prefix must be printed following a '\n'
 877 */
 878static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 879{
 880        if ((diff_words->last_minus == 0 &&
 881                diff_words->current_plus == diff_words->plus.text.ptr) ||
 882                (diff_words->current_plus > diff_words->plus.text.ptr &&
 883                *(diff_words->current_plus - 1) == '\n')) {
 884                return 1;
 885        } else {
 886                return 0;
 887        }
 888}
 889
 890static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 891{
 892        struct diff_words_data *diff_words = priv;
 893        struct diff_words_style *style = diff_words->style;
 894        int minus_first, minus_len, plus_first, plus_len;
 895        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 896        struct diff_options *opt = diff_words->opt;
 897        const char *line_prefix;
 898
 899        if (line[0] != '@' || parse_hunk_header(line, len,
 900                        &minus_first, &minus_len, &plus_first, &plus_len))
 901                return;
 902
 903        assert(opt);
 904        line_prefix = diff_line_prefix(opt);
 905
 906        /* POSIX requires that first be decremented by one if len == 0... */
 907        if (minus_len) {
 908                minus_begin = diff_words->minus.orig[minus_first].begin;
 909                minus_end =
 910                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 911        } else
 912                minus_begin = minus_end =
 913                        diff_words->minus.orig[minus_first].end;
 914
 915        if (plus_len) {
 916                plus_begin = diff_words->plus.orig[plus_first].begin;
 917                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 918        } else
 919                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 920
 921        if (color_words_output_graph_prefix(diff_words)) {
 922                fputs(line_prefix, diff_words->opt->file);
 923        }
 924        if (diff_words->current_plus != plus_begin) {
 925                fn_out_diff_words_write_helper(diff_words->opt->file,
 926                                &style->ctx, style->newline,
 927                                plus_begin - diff_words->current_plus,
 928                                diff_words->current_plus, line_prefix);
 929                if (*(plus_begin - 1) == '\n')
 930                        fputs(line_prefix, diff_words->opt->file);
 931        }
 932        if (minus_begin != minus_end) {
 933                fn_out_diff_words_write_helper(diff_words->opt->file,
 934                                &style->old, style->newline,
 935                                minus_end - minus_begin, minus_begin,
 936                                line_prefix);
 937        }
 938        if (plus_begin != plus_end) {
 939                fn_out_diff_words_write_helper(diff_words->opt->file,
 940                                &style->new, style->newline,
 941                                plus_end - plus_begin, plus_begin,
 942                                line_prefix);
 943        }
 944
 945        diff_words->current_plus = plus_end;
 946        diff_words->last_minus = minus_first;
 947}
 948
 949/* This function starts looking at *begin, and returns 0 iff a word was found. */
 950static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 951                int *begin, int *end)
 952{
 953        if (word_regex && *begin < buffer->size) {
 954                regmatch_t match[1];
 955                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 956                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 957                                        '\n', match[0].rm_eo - match[0].rm_so);
 958                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 959                        *begin += match[0].rm_so;
 960                        return *begin >= *end;
 961                }
 962                return -1;
 963        }
 964
 965        /* find the next word */
 966        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 967                (*begin)++;
 968        if (*begin >= buffer->size)
 969                return -1;
 970
 971        /* find the end of the word */
 972        *end = *begin + 1;
 973        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 974                (*end)++;
 975
 976        return 0;
 977}
 978
 979/*
 980 * This function splits the words in buffer->text, stores the list with
 981 * newline separator into out, and saves the offsets of the original words
 982 * in buffer->orig.
 983 */
 984static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 985                regex_t *word_regex)
 986{
 987        int i, j;
 988        long alloc = 0;
 989
 990        out->size = 0;
 991        out->ptr = NULL;
 992
 993        /* fake an empty "0th" word */
 994        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 995        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 996        buffer->orig_nr = 1;
 997
 998        for (i = 0; i < buffer->text.size; i++) {
 999                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
1000                        return;
1001
1002                /* store original boundaries */
1003                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
1004                                buffer->orig_alloc);
1005                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
1006                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
1007                buffer->orig_nr++;
1008
1009                /* store one word */
1010                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
1011                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
1012                out->ptr[out->size + j - i] = '\n';
1013                out->size += j - i + 1;
1014
1015                i = j - 1;
1016        }
1017}
1018
1019/* this executes the word diff on the accumulated buffers */
1020static void diff_words_show(struct diff_words_data *diff_words)
1021{
1022        xpparam_t xpp;
1023        xdemitconf_t xecfg;
1024        mmfile_t minus, plus;
1025        struct diff_words_style *style = diff_words->style;
1026
1027        struct diff_options *opt = diff_words->opt;
1028        const char *line_prefix;
1029
1030        assert(opt);
1031        line_prefix = diff_line_prefix(opt);
1032
1033        /* special case: only removal */
1034        if (!diff_words->plus.text.size) {
1035                fputs(line_prefix, diff_words->opt->file);
1036                fn_out_diff_words_write_helper(diff_words->opt->file,
1037                        &style->old, style->newline,
1038                        diff_words->minus.text.size,
1039                        diff_words->minus.text.ptr, line_prefix);
1040                diff_words->minus.text.size = 0;
1041                return;
1042        }
1043
1044        diff_words->current_plus = diff_words->plus.text.ptr;
1045        diff_words->last_minus = 0;
1046
1047        memset(&xpp, 0, sizeof(xpp));
1048        memset(&xecfg, 0, sizeof(xecfg));
1049        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
1050        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
1051        xpp.flags = 0;
1052        /* as only the hunk header will be parsed, we need a 0-context */
1053        xecfg.ctxlen = 0;
1054        if (xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
1055                          &xpp, &xecfg))
1056                die("unable to generate word diff");
1057        free(minus.ptr);
1058        free(plus.ptr);
1059        if (diff_words->current_plus != diff_words->plus.text.ptr +
1060                        diff_words->plus.text.size) {
1061                if (color_words_output_graph_prefix(diff_words))
1062                        fputs(line_prefix, diff_words->opt->file);
1063                fn_out_diff_words_write_helper(diff_words->opt->file,
1064                        &style->ctx, style->newline,
1065                        diff_words->plus.text.ptr + diff_words->plus.text.size
1066                        - diff_words->current_plus, diff_words->current_plus,
1067                        line_prefix);
1068        }
1069        diff_words->minus.text.size = diff_words->plus.text.size = 0;
1070}
1071
1072/* In "color-words" mode, show word-diff of words accumulated in the buffer */
1073static void diff_words_flush(struct emit_callback *ecbdata)
1074{
1075        if (ecbdata->diff_words->minus.text.size ||
1076            ecbdata->diff_words->plus.text.size)
1077                diff_words_show(ecbdata->diff_words);
1078}
1079
1080static void diff_filespec_load_driver(struct diff_filespec *one)
1081{
1082        /* Use already-loaded driver */
1083        if (one->driver)
1084                return;
1085
1086        if (S_ISREG(one->mode))
1087                one->driver = userdiff_find_by_path(one->path);
1088
1089        /* Fallback to default settings */
1090        if (!one->driver)
1091                one->driver = userdiff_find_by_name("default");
1092}
1093
1094static const char *userdiff_word_regex(struct diff_filespec *one)
1095{
1096        diff_filespec_load_driver(one);
1097        return one->driver->word_regex;
1098}
1099
1100static void init_diff_words_data(struct emit_callback *ecbdata,
1101                                 struct diff_options *orig_opts,
1102                                 struct diff_filespec *one,
1103                                 struct diff_filespec *two)
1104{
1105        int i;
1106        struct diff_options *o = xmalloc(sizeof(struct diff_options));
1107        memcpy(o, orig_opts, sizeof(struct diff_options));
1108
1109        ecbdata->diff_words =
1110                xcalloc(1, sizeof(struct diff_words_data));
1111        ecbdata->diff_words->type = o->word_diff;
1112        ecbdata->diff_words->opt = o;
1113        if (!o->word_regex)
1114                o->word_regex = userdiff_word_regex(one);
1115        if (!o->word_regex)
1116                o->word_regex = userdiff_word_regex(two);
1117        if (!o->word_regex)
1118                o->word_regex = diff_word_regex_cfg;
1119        if (o->word_regex) {
1120                ecbdata->diff_words->word_regex = (regex_t *)
1121                        xmalloc(sizeof(regex_t));
1122                if (regcomp(ecbdata->diff_words->word_regex,
1123                            o->word_regex,
1124                            REG_EXTENDED | REG_NEWLINE))
1125                        die ("Invalid regular expression: %s",
1126                             o->word_regex);
1127        }
1128        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1129                if (o->word_diff == diff_words_styles[i].type) {
1130                        ecbdata->diff_words->style =
1131                                &diff_words_styles[i];
1132                        break;
1133                }
1134        }
1135        if (want_color(o->use_color)) {
1136                struct diff_words_style *st = ecbdata->diff_words->style;
1137                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1138                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1139                st->ctx.color = diff_get_color_opt(o, DIFF_CONTEXT);
1140        }
1141}
1142
1143static void free_diff_words_data(struct emit_callback *ecbdata)
1144{
1145        if (ecbdata->diff_words) {
1146                diff_words_flush(ecbdata);
1147                free (ecbdata->diff_words->opt);
1148                free (ecbdata->diff_words->minus.text.ptr);
1149                free (ecbdata->diff_words->minus.orig);
1150                free (ecbdata->diff_words->plus.text.ptr);
1151                free (ecbdata->diff_words->plus.orig);
1152                if (ecbdata->diff_words->word_regex) {
1153                        regfree(ecbdata->diff_words->word_regex);
1154                        free(ecbdata->diff_words->word_regex);
1155                }
1156                free(ecbdata->diff_words);
1157                ecbdata->diff_words = NULL;
1158        }
1159}
1160
1161const char *diff_get_color(int diff_use_color, enum color_diff ix)
1162{
1163        if (want_color(diff_use_color))
1164                return diff_colors[ix];
1165        return "";
1166}
1167
1168const char *diff_line_prefix(struct diff_options *opt)
1169{
1170        struct strbuf *msgbuf;
1171        if (!opt->output_prefix)
1172                return "";
1173
1174        msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
1175        return msgbuf->buf;
1176}
1177
1178static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
1179{
1180        const char *cp;
1181        unsigned long allot;
1182        size_t l = len;
1183
1184        if (ecb->truncate)
1185                return ecb->truncate(line, len);
1186        cp = line;
1187        allot = l;
1188        while (0 < l) {
1189                (void) utf8_width(&cp, &l);
1190                if (!cp)
1191                        break; /* truncated in the middle? */
1192        }
1193        return allot - l;
1194}
1195
1196static void find_lno(const char *line, struct emit_callback *ecbdata)
1197{
1198        const char *p;
1199        ecbdata->lno_in_preimage = 0;
1200        ecbdata->lno_in_postimage = 0;
1201        p = strchr(line, '-');
1202        if (!p)
1203                return; /* cannot happen */
1204        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
1205        p = strchr(p, '+');
1206        if (!p)
1207                return; /* cannot happen */
1208        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
1209}
1210
1211static void fn_out_consume(void *priv, char *line, unsigned long len)
1212{
1213        struct emit_callback *ecbdata = priv;
1214        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
1215        const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
1216        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
1217        struct diff_options *o = ecbdata->opt;
1218        const char *line_prefix = diff_line_prefix(o);
1219
1220        o->found_changes = 1;
1221
1222        if (ecbdata->header) {
1223                fprintf(o->file, "%s", ecbdata->header->buf);
1224                strbuf_reset(ecbdata->header);
1225                ecbdata->header = NULL;
1226        }
1227
1228        if (ecbdata->label_path[0]) {
1229                const char *name_a_tab, *name_b_tab;
1230
1231                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
1232                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
1233
1234                fprintf(o->file, "%s%s--- %s%s%s\n",
1235                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
1236                fprintf(o->file, "%s%s+++ %s%s%s\n",
1237                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
1238                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
1239        }
1240
1241        if (diff_suppress_blank_empty
1242            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1243                line[0] = '\n';
1244                len = 1;
1245        }
1246
1247        if (line[0] == '@') {
1248                if (ecbdata->diff_words)
1249                        diff_words_flush(ecbdata);
1250                len = sane_truncate_line(ecbdata, line, len);
1251                find_lno(line, ecbdata);
1252                emit_hunk_header(ecbdata, line, len);
1253                if (line[len-1] != '\n')
1254                        putc('\n', o->file);
1255                return;
1256        }
1257
1258        if (ecbdata->diff_words) {
1259                if (line[0] == '-') {
1260                        diff_words_append(line, len,
1261                                          &ecbdata->diff_words->minus);
1262                        return;
1263                } else if (line[0] == '+') {
1264                        diff_words_append(line, len,
1265                                          &ecbdata->diff_words->plus);
1266                        return;
1267                } else if (starts_with(line, "\\ ")) {
1268                        /*
1269                         * Eat the "no newline at eof" marker as if we
1270                         * saw a "+" or "-" line with nothing on it,
1271                         * and return without diff_words_flush() to
1272                         * defer processing. If this is the end of
1273                         * preimage, more "+" lines may come after it.
1274                         */
1275                        return;
1276                }
1277                diff_words_flush(ecbdata);
1278                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1279                        emit_line(o, context, reset, line, len);
1280                        fputs("~\n", o->file);
1281                } else {
1282                        /*
1283                         * Skip the prefix character, if any.  With
1284                         * diff_suppress_blank_empty, there may be
1285                         * none.
1286                         */
1287                        if (line[0] != '\n') {
1288                              line++;
1289                              len--;
1290                        }
1291                        emit_line(o, context, reset, line, len);
1292                }
1293                return;
1294        }
1295
1296        switch (line[0]) {
1297        case '+':
1298                ecbdata->lno_in_postimage++;
1299                emit_add_line(reset, ecbdata, line + 1, len - 1);
1300                break;
1301        case '-':
1302                ecbdata->lno_in_preimage++;
1303                emit_del_line(reset, ecbdata, line + 1, len - 1);
1304                break;
1305        case ' ':
1306                ecbdata->lno_in_postimage++;
1307                ecbdata->lno_in_preimage++;
1308                emit_context_line(reset, ecbdata, line + 1, len - 1);
1309                break;
1310        default:
1311                /* incomplete line at the end */
1312                ecbdata->lno_in_preimage++;
1313                emit_line(o, diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
1314                          reset, line, len);
1315                break;
1316        }
1317}
1318
1319static char *pprint_rename(const char *a, const char *b)
1320{
1321        const char *old = a;
1322        const char *new = b;
1323        struct strbuf name = STRBUF_INIT;
1324        int pfx_length, sfx_length;
1325        int pfx_adjust_for_slash;
1326        int len_a = strlen(a);
1327        int len_b = strlen(b);
1328        int a_midlen, b_midlen;
1329        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1330        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1331
1332        if (qlen_a || qlen_b) {
1333                quote_c_style(a, &name, NULL, 0);
1334                strbuf_addstr(&name, " => ");
1335                quote_c_style(b, &name, NULL, 0);
1336                return strbuf_detach(&name, NULL);
1337        }
1338
1339        /* Find common prefix */
1340        pfx_length = 0;
1341        while (*old && *new && *old == *new) {
1342                if (*old == '/')
1343                        pfx_length = old - a + 1;
1344                old++;
1345                new++;
1346        }
1347
1348        /* Find common suffix */
1349        old = a + len_a;
1350        new = b + len_b;
1351        sfx_length = 0;
1352        /*
1353         * If there is a common prefix, it must end in a slash.  In
1354         * that case we let this loop run 1 into the prefix to see the
1355         * same slash.
1356         *
1357         * If there is no common prefix, we cannot do this as it would
1358         * underrun the input strings.
1359         */
1360        pfx_adjust_for_slash = (pfx_length ? 1 : 0);
1361        while (a + pfx_length - pfx_adjust_for_slash <= old &&
1362               b + pfx_length - pfx_adjust_for_slash <= new &&
1363               *old == *new) {
1364                if (*old == '/')
1365                        sfx_length = len_a - (old - a);
1366                old--;
1367                new--;
1368        }
1369
1370        /*
1371         * pfx{mid-a => mid-b}sfx
1372         * {pfx-a => pfx-b}sfx
1373         * pfx{sfx-a => sfx-b}
1374         * name-a => name-b
1375         */
1376        a_midlen = len_a - pfx_length - sfx_length;
1377        b_midlen = len_b - pfx_length - sfx_length;
1378        if (a_midlen < 0)
1379                a_midlen = 0;
1380        if (b_midlen < 0)
1381                b_midlen = 0;
1382
1383        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1384        if (pfx_length + sfx_length) {
1385                strbuf_add(&name, a, pfx_length);
1386                strbuf_addch(&name, '{');
1387        }
1388        strbuf_add(&name, a + pfx_length, a_midlen);
1389        strbuf_addstr(&name, " => ");
1390        strbuf_add(&name, b + pfx_length, b_midlen);
1391        if (pfx_length + sfx_length) {
1392                strbuf_addch(&name, '}');
1393                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1394        }
1395        return strbuf_detach(&name, NULL);
1396}
1397
1398struct diffstat_t {
1399        int nr;
1400        int alloc;
1401        struct diffstat_file {
1402                char *from_name;
1403                char *name;
1404                char *print_name;
1405                unsigned is_unmerged:1;
1406                unsigned is_binary:1;
1407                unsigned is_renamed:1;
1408                unsigned is_interesting:1;
1409                uintmax_t added, deleted;
1410        } **files;
1411};
1412
1413static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1414                                          const char *name_a,
1415                                          const char *name_b)
1416{
1417        struct diffstat_file *x;
1418        x = xcalloc(1, sizeof(*x));
1419        ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
1420        diffstat->files[diffstat->nr++] = x;
1421        if (name_b) {
1422                x->from_name = xstrdup(name_a);
1423                x->name = xstrdup(name_b);
1424                x->is_renamed = 1;
1425        }
1426        else {
1427                x->from_name = NULL;
1428                x->name = xstrdup(name_a);
1429        }
1430        return x;
1431}
1432
1433static void diffstat_consume(void *priv, char *line, unsigned long len)
1434{
1435        struct diffstat_t *diffstat = priv;
1436        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1437
1438        if (line[0] == '+')
1439                x->added++;
1440        else if (line[0] == '-')
1441                x->deleted++;
1442}
1443
1444const char mime_boundary_leader[] = "------------";
1445
1446static int scale_linear(int it, int width, int max_change)
1447{
1448        if (!it)
1449                return 0;
1450        /*
1451         * make sure that at least one '-' or '+' is printed if
1452         * there is any change to this path. The easiest way is to
1453         * scale linearly as if the alloted width is one column shorter
1454         * than it is, and then add 1 to the result.
1455         */
1456        return 1 + (it * (width - 1) / max_change);
1457}
1458
1459static void show_name(FILE *file,
1460                      const char *prefix, const char *name, int len)
1461{
1462        fprintf(file, " %s%-*s |", prefix, len, name);
1463}
1464
1465static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1466{
1467        if (cnt <= 0)
1468                return;
1469        fprintf(file, "%s", set);
1470        while (cnt--)
1471                putc(ch, file);
1472        fprintf(file, "%s", reset);
1473}
1474
1475static void fill_print_name(struct diffstat_file *file)
1476{
1477        char *pname;
1478
1479        if (file->print_name)
1480                return;
1481
1482        if (!file->is_renamed) {
1483                struct strbuf buf = STRBUF_INIT;
1484                if (quote_c_style(file->name, &buf, NULL, 0)) {
1485                        pname = strbuf_detach(&buf, NULL);
1486                } else {
1487                        pname = file->name;
1488                        strbuf_release(&buf);
1489                }
1490        } else {
1491                pname = pprint_rename(file->from_name, file->name);
1492        }
1493        file->print_name = pname;
1494}
1495
1496int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
1497{
1498        struct strbuf sb = STRBUF_INIT;
1499        int ret;
1500
1501        if (!files) {
1502                assert(insertions == 0 && deletions == 0);
1503                return fprintf(fp, "%s\n", " 0 files changed");
1504        }
1505
1506        strbuf_addf(&sb,
1507                    (files == 1) ? " %d file changed" : " %d files changed",
1508                    files);
1509
1510        /*
1511         * For binary diff, the caller may want to print "x files
1512         * changed" with insertions == 0 && deletions == 0.
1513         *
1514         * Not omitting "0 insertions(+), 0 deletions(-)" in this case
1515         * is probably less confusing (i.e skip over "2 files changed
1516         * but nothing about added/removed lines? Is this a bug in Git?").
1517         */
1518        if (insertions || deletions == 0) {
1519                strbuf_addf(&sb,
1520                            (insertions == 1) ? ", %d insertion(+)" : ", %d insertions(+)",
1521                            insertions);
1522        }
1523
1524        if (deletions || insertions == 0) {
1525                strbuf_addf(&sb,
1526                            (deletions == 1) ? ", %d deletion(-)" : ", %d deletions(-)",
1527                            deletions);
1528        }
1529        strbuf_addch(&sb, '\n');
1530        ret = fputs(sb.buf, fp);
1531        strbuf_release(&sb);
1532        return ret;
1533}
1534
1535static void show_stats(struct diffstat_t *data, struct diff_options *options)
1536{
1537        int i, len, add, del, adds = 0, dels = 0;
1538        uintmax_t max_change = 0, max_len = 0;
1539        int total_files = data->nr, count;
1540        int width, name_width, graph_width, number_width = 0, bin_width = 0;
1541        const char *reset, *add_c, *del_c;
1542        const char *line_prefix = "";
1543        int extra_shown = 0;
1544
1545        if (data->nr == 0)
1546                return;
1547
1548        line_prefix = diff_line_prefix(options);
1549        count = options->stat_count ? options->stat_count : data->nr;
1550
1551        reset = diff_get_color_opt(options, DIFF_RESET);
1552        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1553        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1554
1555        /*
1556         * Find the longest filename and max number of changes
1557         */
1558        for (i = 0; (i < count) && (i < data->nr); i++) {
1559                struct diffstat_file *file = data->files[i];
1560                uintmax_t change = file->added + file->deleted;
1561
1562                if (!file->is_interesting && (change == 0)) {
1563                        count++; /* not shown == room for one more */
1564                        continue;
1565                }
1566                fill_print_name(file);
1567                len = strlen(file->print_name);
1568                if (max_len < len)
1569                        max_len = len;
1570
1571                if (file->is_unmerged) {
1572                        /* "Unmerged" is 8 characters */
1573                        bin_width = bin_width < 8 ? 8 : bin_width;
1574                        continue;
1575                }
1576                if (file->is_binary) {
1577                        /* "Bin XXX -> YYY bytes" */
1578                        int w = 14 + decimal_width(file->added)
1579                                + decimal_width(file->deleted);
1580                        bin_width = bin_width < w ? w : bin_width;
1581                        /* Display change counts aligned with "Bin" */
1582                        number_width = 3;
1583                        continue;
1584                }
1585
1586                if (max_change < change)
1587                        max_change = change;
1588        }
1589        count = i; /* where we can stop scanning in data->files[] */
1590
1591        /*
1592         * We have width = stat_width or term_columns() columns total.
1593         * We want a maximum of min(max_len, stat_name_width) for the name part.
1594         * We want a maximum of min(max_change, stat_graph_width) for the +- part.
1595         * We also need 1 for " " and 4 + decimal_width(max_change)
1596         * for " | NNNN " and one the empty column at the end, altogether
1597         * 6 + decimal_width(max_change).
1598         *
1599         * If there's not enough space, we will use the smaller of
1600         * stat_name_width (if set) and 5/8*width for the filename,
1601         * and the rest for constant elements + graph part, but no more
1602         * than stat_graph_width for the graph part.
1603         * (5/8 gives 50 for filename and 30 for the constant parts + graph
1604         * for the standard terminal size).
1605         *
1606         * In other words: stat_width limits the maximum width, and
1607         * stat_name_width fixes the maximum width of the filename,
1608         * and is also used to divide available columns if there
1609         * aren't enough.
1610         *
1611         * Binary files are displayed with "Bin XXX -> YYY bytes"
1612         * instead of the change count and graph. This part is treated
1613         * similarly to the graph part, except that it is not
1614         * "scaled". If total width is too small to accommodate the
1615         * guaranteed minimum width of the filename part and the
1616         * separators and this message, this message will "overflow"
1617         * making the line longer than the maximum width.
1618         */
1619
1620        if (options->stat_width == -1)
1621                width = term_columns() - strlen(line_prefix);
1622        else
1623                width = options->stat_width ? options->stat_width : 80;
1624        number_width = decimal_width(max_change) > number_width ?
1625                decimal_width(max_change) : number_width;
1626
1627        if (options->stat_graph_width == -1)
1628                options->stat_graph_width = diff_stat_graph_width;
1629
1630        /*
1631         * Guarantee 3/8*16==6 for the graph part
1632         * and 5/8*16==10 for the filename part
1633         */
1634        if (width < 16 + 6 + number_width)
1635                width = 16 + 6 + number_width;
1636
1637        /*
1638         * First assign sizes that are wanted, ignoring available width.
1639         * strlen("Bin XXX -> YYY bytes") == bin_width, and the part
1640         * starting from "XXX" should fit in graph_width.
1641         */
1642        graph_width = max_change + 4 > bin_width ? max_change : bin_width - 4;
1643        if (options->stat_graph_width &&
1644            options->stat_graph_width < graph_width)
1645                graph_width = options->stat_graph_width;
1646
1647        name_width = (options->stat_name_width > 0 &&
1648                      options->stat_name_width < max_len) ?
1649                options->stat_name_width : max_len;
1650
1651        /*
1652         * Adjust adjustable widths not to exceed maximum width
1653         */
1654        if (name_width + number_width + 6 + graph_width > width) {
1655                if (graph_width > width * 3/8 - number_width - 6) {
1656                        graph_width = width * 3/8 - number_width - 6;
1657                        if (graph_width < 6)
1658                                graph_width = 6;
1659                }
1660
1661                if (options->stat_graph_width &&
1662                    graph_width > options->stat_graph_width)
1663                        graph_width = options->stat_graph_width;
1664                if (name_width > width - number_width - 6 - graph_width)
1665                        name_width = width - number_width - 6 - graph_width;
1666                else
1667                        graph_width = width - number_width - 6 - name_width;
1668        }
1669
1670        /*
1671         * From here name_width is the width of the name area,
1672         * and graph_width is the width of the graph area.
1673         * max_change is used to scale graph properly.
1674         */
1675        for (i = 0; i < count; i++) {
1676                const char *prefix = "";
1677                struct diffstat_file *file = data->files[i];
1678                char *name = file->print_name;
1679                uintmax_t added = file->added;
1680                uintmax_t deleted = file->deleted;
1681                int name_len;
1682
1683                if (!file->is_interesting && (added + deleted == 0))
1684                        continue;
1685
1686                /*
1687                 * "scale" the filename
1688                 */
1689                len = name_width;
1690                name_len = strlen(name);
1691                if (name_width < name_len) {
1692                        char *slash;
1693                        prefix = "...";
1694                        len -= 3;
1695                        name += name_len - len;
1696                        slash = strchr(name, '/');
1697                        if (slash)
1698                                name = slash;
1699                }
1700
1701                if (file->is_binary) {
1702                        fprintf(options->file, "%s", line_prefix);
1703                        show_name(options->file, prefix, name, len);
1704                        fprintf(options->file, " %*s", number_width, "Bin");
1705                        if (!added && !deleted) {
1706                                putc('\n', options->file);
1707                                continue;
1708                        }
1709                        fprintf(options->file, " %s%"PRIuMAX"%s",
1710                                del_c, deleted, reset);
1711                        fprintf(options->file, " -> ");
1712                        fprintf(options->file, "%s%"PRIuMAX"%s",
1713                                add_c, added, reset);
1714                        fprintf(options->file, " bytes");
1715                        fprintf(options->file, "\n");
1716                        continue;
1717                }
1718                else if (file->is_unmerged) {
1719                        fprintf(options->file, "%s", line_prefix);
1720                        show_name(options->file, prefix, name, len);
1721                        fprintf(options->file, " Unmerged\n");
1722                        continue;
1723                }
1724
1725                /*
1726                 * scale the add/delete
1727                 */
1728                add = added;
1729                del = deleted;
1730
1731                if (graph_width <= max_change) {
1732                        int total = scale_linear(add + del, graph_width, max_change);
1733                        if (total < 2 && add && del)
1734                                /* width >= 2 due to the sanity check */
1735                                total = 2;
1736                        if (add < del) {
1737                                add = scale_linear(add, graph_width, max_change);
1738                                del = total - add;
1739                        } else {
1740                                del = scale_linear(del, graph_width, max_change);
1741                                add = total - del;
1742                        }
1743                }
1744                fprintf(options->file, "%s", line_prefix);
1745                show_name(options->file, prefix, name, len);
1746                fprintf(options->file, " %*"PRIuMAX"%s",
1747                        number_width, added + deleted,
1748                        added + deleted ? " " : "");
1749                show_graph(options->file, '+', add, add_c, reset);
1750                show_graph(options->file, '-', del, del_c, reset);
1751                fprintf(options->file, "\n");
1752        }
1753
1754        for (i = 0; i < data->nr; i++) {
1755                struct diffstat_file *file = data->files[i];
1756                uintmax_t added = file->added;
1757                uintmax_t deleted = file->deleted;
1758
1759                if (file->is_unmerged ||
1760                    (!file->is_interesting && (added + deleted == 0))) {
1761                        total_files--;
1762                        continue;
1763                }
1764
1765                if (!file->is_binary) {
1766                        adds += added;
1767                        dels += deleted;
1768                }
1769                if (i < count)
1770                        continue;
1771                if (!extra_shown)
1772                        fprintf(options->file, "%s ...\n", line_prefix);
1773                extra_shown = 1;
1774        }
1775        fprintf(options->file, "%s", line_prefix);
1776        print_stat_summary(options->file, total_files, adds, dels);
1777}
1778
1779static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1780{
1781        int i, adds = 0, dels = 0, total_files = data->nr;
1782
1783        if (data->nr == 0)
1784                return;
1785
1786        for (i = 0; i < data->nr; i++) {
1787                int added = data->files[i]->added;
1788                int deleted= data->files[i]->deleted;
1789
1790                if (data->files[i]->is_unmerged ||
1791                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
1792                        total_files--;
1793                } else if (!data->files[i]->is_binary) { /* don't count bytes */
1794                        adds += added;
1795                        dels += deleted;
1796                }
1797        }
1798        fprintf(options->file, "%s", diff_line_prefix(options));
1799        print_stat_summary(options->file, total_files, adds, dels);
1800}
1801
1802static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1803{
1804        int i;
1805
1806        if (data->nr == 0)
1807                return;
1808
1809        for (i = 0; i < data->nr; i++) {
1810                struct diffstat_file *file = data->files[i];
1811
1812                fprintf(options->file, "%s", diff_line_prefix(options));
1813
1814                if (file->is_binary)
1815                        fprintf(options->file, "-\t-\t");
1816                else
1817                        fprintf(options->file,
1818                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1819                                file->added, file->deleted);
1820                if (options->line_termination) {
1821                        fill_print_name(file);
1822                        if (!file->is_renamed)
1823                                write_name_quoted(file->name, options->file,
1824                                                  options->line_termination);
1825                        else {
1826                                fputs(file->print_name, options->file);
1827                                putc(options->line_termination, options->file);
1828                        }
1829                } else {
1830                        if (file->is_renamed) {
1831                                putc('\0', options->file);
1832                                write_name_quoted(file->from_name, options->file, '\0');
1833                        }
1834                        write_name_quoted(file->name, options->file, '\0');
1835                }
1836        }
1837}
1838
1839struct dirstat_file {
1840        const char *name;
1841        unsigned long changed;
1842};
1843
1844struct dirstat_dir {
1845        struct dirstat_file *files;
1846        int alloc, nr, permille, cumulative;
1847};
1848
1849static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1850                unsigned long changed, const char *base, int baselen)
1851{
1852        unsigned long this_dir = 0;
1853        unsigned int sources = 0;
1854        const char *line_prefix = diff_line_prefix(opt);
1855
1856        while (dir->nr) {
1857                struct dirstat_file *f = dir->files;
1858                int namelen = strlen(f->name);
1859                unsigned long this;
1860                char *slash;
1861
1862                if (namelen < baselen)
1863                        break;
1864                if (memcmp(f->name, base, baselen))
1865                        break;
1866                slash = strchr(f->name + baselen, '/');
1867                if (slash) {
1868                        int newbaselen = slash + 1 - f->name;
1869                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1870                        sources++;
1871                } else {
1872                        this = f->changed;
1873                        dir->files++;
1874                        dir->nr--;
1875                        sources += 2;
1876                }
1877                this_dir += this;
1878        }
1879
1880        /*
1881         * We don't report dirstat's for
1882         *  - the top level
1883         *  - or cases where everything came from a single directory
1884         *    under this directory (sources == 1).
1885         */
1886        if (baselen && sources != 1) {
1887                if (this_dir) {
1888                        int permille = this_dir * 1000 / changed;
1889                        if (permille >= dir->permille) {
1890                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1891                                        permille / 10, permille % 10, baselen, base);
1892                                if (!dir->cumulative)
1893                                        return 0;
1894                        }
1895                }
1896        }
1897        return this_dir;
1898}
1899
1900static int dirstat_compare(const void *_a, const void *_b)
1901{
1902        const struct dirstat_file *a = _a;
1903        const struct dirstat_file *b = _b;
1904        return strcmp(a->name, b->name);
1905}
1906
1907static void show_dirstat(struct diff_options *options)
1908{
1909        int i;
1910        unsigned long changed;
1911        struct dirstat_dir dir;
1912        struct diff_queue_struct *q = &diff_queued_diff;
1913
1914        dir.files = NULL;
1915        dir.alloc = 0;
1916        dir.nr = 0;
1917        dir.permille = options->dirstat_permille;
1918        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1919
1920        changed = 0;
1921        for (i = 0; i < q->nr; i++) {
1922                struct diff_filepair *p = q->queue[i];
1923                const char *name;
1924                unsigned long copied, added, damage;
1925                int content_changed;
1926
1927                name = p->two->path ? p->two->path : p->one->path;
1928
1929                if (p->one->oid_valid && p->two->oid_valid)
1930                        content_changed = oidcmp(&p->one->oid, &p->two->oid);
1931                else
1932                        content_changed = 1;
1933
1934                if (!content_changed) {
1935                        /*
1936                         * The SHA1 has not changed, so pre-/post-content is
1937                         * identical. We can therefore skip looking at the
1938                         * file contents altogether.
1939                         */
1940                        damage = 0;
1941                        goto found_damage;
1942                }
1943
1944                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE)) {
1945                        /*
1946                         * In --dirstat-by-file mode, we don't really need to
1947                         * look at the actual file contents at all.
1948                         * The fact that the SHA1 changed is enough for us to
1949                         * add this file to the list of results
1950                         * (with each file contributing equal damage).
1951                         */
1952                        damage = 1;
1953                        goto found_damage;
1954                }
1955
1956                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1957                        diff_populate_filespec(p->one, 0);
1958                        diff_populate_filespec(p->two, 0);
1959                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1960                                               &copied, &added);
1961                        diff_free_filespec_data(p->one);
1962                        diff_free_filespec_data(p->two);
1963                } else if (DIFF_FILE_VALID(p->one)) {
1964                        diff_populate_filespec(p->one, CHECK_SIZE_ONLY);
1965                        copied = added = 0;
1966                        diff_free_filespec_data(p->one);
1967                } else if (DIFF_FILE_VALID(p->two)) {
1968                        diff_populate_filespec(p->two, CHECK_SIZE_ONLY);
1969                        copied = 0;
1970                        added = p->two->size;
1971                        diff_free_filespec_data(p->two);
1972                } else
1973                        continue;
1974
1975                /*
1976                 * Original minus copied is the removed material,
1977                 * added is the new material.  They are both damages
1978                 * made to the preimage.
1979                 * If the resulting damage is zero, we know that
1980                 * diffcore_count_changes() considers the two entries to
1981                 * be identical, but since content_changed is true, we
1982                 * know that there must have been _some_ kind of change,
1983                 * so we force all entries to have damage > 0.
1984                 */
1985                damage = (p->one->size - copied) + added;
1986                if (!damage)
1987                        damage = 1;
1988
1989found_damage:
1990                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1991                dir.files[dir.nr].name = name;
1992                dir.files[dir.nr].changed = damage;
1993                changed += damage;
1994                dir.nr++;
1995        }
1996
1997        /* This can happen even with many files, if everything was renames */
1998        if (!changed)
1999                return;
2000
2001        /* Show all directories with more than x% of the changes */
2002        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2003        gather_dirstat(options, &dir, changed, "", 0);
2004}
2005
2006static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *options)
2007{
2008        int i;
2009        unsigned long changed;
2010        struct dirstat_dir dir;
2011
2012        if (data->nr == 0)
2013                return;
2014
2015        dir.files = NULL;
2016        dir.alloc = 0;
2017        dir.nr = 0;
2018        dir.permille = options->dirstat_permille;
2019        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
2020
2021        changed = 0;
2022        for (i = 0; i < data->nr; i++) {
2023                struct diffstat_file *file = data->files[i];
2024                unsigned long damage = file->added + file->deleted;
2025                if (file->is_binary)
2026                        /*
2027                         * binary files counts bytes, not lines. Must find some
2028                         * way to normalize binary bytes vs. textual lines.
2029                         * The following heuristic assumes that there are 64
2030                         * bytes per "line".
2031                         * This is stupid and ugly, but very cheap...
2032                         */
2033                        damage = (damage + 63) / 64;
2034                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
2035                dir.files[dir.nr].name = file->name;
2036                dir.files[dir.nr].changed = damage;
2037                changed += damage;
2038                dir.nr++;
2039        }
2040
2041        /* This can happen even with many files, if everything was renames */
2042        if (!changed)
2043                return;
2044
2045        /* Show all directories with more than x% of the changes */
2046        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
2047        gather_dirstat(options, &dir, changed, "", 0);
2048}
2049
2050static void free_diffstat_info(struct diffstat_t *diffstat)
2051{
2052        int i;
2053        for (i = 0; i < diffstat->nr; i++) {
2054                struct diffstat_file *f = diffstat->files[i];
2055                if (f->name != f->print_name)
2056                        free(f->print_name);
2057                free(f->name);
2058                free(f->from_name);
2059                free(f);
2060        }
2061        free(diffstat->files);
2062}
2063
2064struct checkdiff_t {
2065        const char *filename;
2066        int lineno;
2067        int conflict_marker_size;
2068        struct diff_options *o;
2069        unsigned ws_rule;
2070        unsigned status;
2071};
2072
2073static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
2074{
2075        char firstchar;
2076        int cnt;
2077
2078        if (len < marker_size + 1)
2079                return 0;
2080        firstchar = line[0];
2081        switch (firstchar) {
2082        case '=': case '>': case '<': case '|':
2083                break;
2084        default:
2085                return 0;
2086        }
2087        for (cnt = 1; cnt < marker_size; cnt++)
2088                if (line[cnt] != firstchar)
2089                        return 0;
2090        /* line[1] thru line[marker_size-1] are same as firstchar */
2091        if (len < marker_size + 1 || !isspace(line[marker_size]))
2092                return 0;
2093        return 1;
2094}
2095
2096static void checkdiff_consume(void *priv, char *line, unsigned long len)
2097{
2098        struct checkdiff_t *data = priv;
2099        int marker_size = data->conflict_marker_size;
2100        const char *ws = diff_get_color(data->o->use_color, DIFF_WHITESPACE);
2101        const char *reset = diff_get_color(data->o->use_color, DIFF_RESET);
2102        const char *set = diff_get_color(data->o->use_color, DIFF_FILE_NEW);
2103        char *err;
2104        const char *line_prefix;
2105
2106        assert(data->o);
2107        line_prefix = diff_line_prefix(data->o);
2108
2109        if (line[0] == '+') {
2110                unsigned bad;
2111                data->lineno++;
2112                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
2113                        data->status |= 1;
2114                        fprintf(data->o->file,
2115                                "%s%s:%d: leftover conflict marker\n",
2116                                line_prefix, data->filename, data->lineno);
2117                }
2118                bad = ws_check(line + 1, len - 1, data->ws_rule);
2119                if (!bad)
2120                        return;
2121                data->status |= bad;
2122                err = whitespace_error_string(bad);
2123                fprintf(data->o->file, "%s%s:%d: %s.\n",
2124                        line_prefix, data->filename, data->lineno, err);
2125                free(err);
2126                emit_line(data->o, set, reset, line, 1);
2127                ws_check_emit(line + 1, len - 1, data->ws_rule,
2128                              data->o->file, set, reset, ws);
2129        } else if (line[0] == ' ') {
2130                data->lineno++;
2131        } else if (line[0] == '@') {
2132                char *plus = strchr(line, '+');
2133                if (plus)
2134                        data->lineno = strtol(plus, NULL, 10) - 1;
2135                else
2136                        die("invalid diff");
2137        }
2138}
2139
2140static unsigned char *deflate_it(char *data,
2141                                 unsigned long size,
2142                                 unsigned long *result_size)
2143{
2144        int bound;
2145        unsigned char *deflated;
2146        git_zstream stream;
2147
2148        git_deflate_init(&stream, zlib_compression_level);
2149        bound = git_deflate_bound(&stream, size);
2150        deflated = xmalloc(bound);
2151        stream.next_out = deflated;
2152        stream.avail_out = bound;
2153
2154        stream.next_in = (unsigned char *)data;
2155        stream.avail_in = size;
2156        while (git_deflate(&stream, Z_FINISH) == Z_OK)
2157                ; /* nothing */
2158        git_deflate_end(&stream);
2159        *result_size = stream.total_out;
2160        return deflated;
2161}
2162
2163static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
2164                                  const char *prefix)
2165{
2166        void *cp;
2167        void *delta;
2168        void *deflated;
2169        void *data;
2170        unsigned long orig_size;
2171        unsigned long delta_size;
2172        unsigned long deflate_size;
2173        unsigned long data_size;
2174
2175        /* We could do deflated delta, or we could do just deflated two,
2176         * whichever is smaller.
2177         */
2178        delta = NULL;
2179        deflated = deflate_it(two->ptr, two->size, &deflate_size);
2180        if (one->size && two->size) {
2181                delta = diff_delta(one->ptr, one->size,
2182                                   two->ptr, two->size,
2183                                   &delta_size, deflate_size);
2184                if (delta) {
2185                        void *to_free = delta;
2186                        orig_size = delta_size;
2187                        delta = deflate_it(delta, delta_size, &delta_size);
2188                        free(to_free);
2189                }
2190        }
2191
2192        if (delta && delta_size < deflate_size) {
2193                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
2194                free(deflated);
2195                data = delta;
2196                data_size = delta_size;
2197        }
2198        else {
2199                fprintf(file, "%sliteral %lu\n", prefix, two->size);
2200                free(delta);
2201                data = deflated;
2202                data_size = deflate_size;
2203        }
2204
2205        /* emit data encoded in base85 */
2206        cp = data;
2207        while (data_size) {
2208                int bytes = (52 < data_size) ? 52 : data_size;
2209                char line[70];
2210                data_size -= bytes;
2211                if (bytes <= 26)
2212                        line[0] = bytes + 'A' - 1;
2213                else
2214                        line[0] = bytes - 26 + 'a' - 1;
2215                encode_85(line + 1, cp, bytes);
2216                cp = (char *) cp + bytes;
2217                fprintf(file, "%s", prefix);
2218                fputs(line, file);
2219                fputc('\n', file);
2220        }
2221        fprintf(file, "%s\n", prefix);
2222        free(data);
2223}
2224
2225static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
2226                             const char *prefix)
2227{
2228        fprintf(file, "%sGIT binary patch\n", prefix);
2229        emit_binary_diff_body(file, one, two, prefix);
2230        emit_binary_diff_body(file, two, one, prefix);
2231}
2232
2233int diff_filespec_is_binary(struct diff_filespec *one)
2234{
2235        if (one->is_binary == -1) {
2236                diff_filespec_load_driver(one);
2237                if (one->driver->binary != -1)
2238                        one->is_binary = one->driver->binary;
2239                else {
2240                        if (!one->data && DIFF_FILE_VALID(one))
2241                                diff_populate_filespec(one, CHECK_BINARY);
2242                        if (one->is_binary == -1 && one->data)
2243                                one->is_binary = buffer_is_binary(one->data,
2244                                                one->size);
2245                        if (one->is_binary == -1)
2246                                one->is_binary = 0;
2247                }
2248        }
2249        return one->is_binary;
2250}
2251
2252static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
2253{
2254        diff_filespec_load_driver(one);
2255        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
2256}
2257
2258void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
2259{
2260        if (!options->a_prefix)
2261                options->a_prefix = a;
2262        if (!options->b_prefix)
2263                options->b_prefix = b;
2264}
2265
2266struct userdiff_driver *get_textconv(struct diff_filespec *one)
2267{
2268        if (!DIFF_FILE_VALID(one))
2269                return NULL;
2270
2271        diff_filespec_load_driver(one);
2272        return userdiff_get_textconv(one->driver);
2273}
2274
2275static void builtin_diff(const char *name_a,
2276                         const char *name_b,
2277                         struct diff_filespec *one,
2278                         struct diff_filespec *two,
2279                         const char *xfrm_msg,
2280                         int must_show_header,
2281                         struct diff_options *o,
2282                         int complete_rewrite)
2283{
2284        mmfile_t mf1, mf2;
2285        const char *lbl[2];
2286        char *a_one, *b_two;
2287        const char *meta = diff_get_color_opt(o, DIFF_METAINFO);
2288        const char *reset = diff_get_color_opt(o, DIFF_RESET);
2289        const char *a_prefix, *b_prefix;
2290        struct userdiff_driver *textconv_one = NULL;
2291        struct userdiff_driver *textconv_two = NULL;
2292        struct strbuf header = STRBUF_INIT;
2293        const char *line_prefix = diff_line_prefix(o);
2294
2295        diff_set_mnemonic_prefix(o, "a/", "b/");
2296        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
2297                a_prefix = o->b_prefix;
2298                b_prefix = o->a_prefix;
2299        } else {
2300                a_prefix = o->a_prefix;
2301                b_prefix = o->b_prefix;
2302        }
2303
2304        if (o->submodule_format == DIFF_SUBMODULE_LOG &&
2305            (!one->mode || S_ISGITLINK(one->mode)) &&
2306            (!two->mode || S_ISGITLINK(two->mode))) {
2307                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2308                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2309                show_submodule_summary(o->file, one->path ? one->path : two->path,
2310                                line_prefix,
2311                                &one->oid, &two->oid,
2312                                two->dirty_submodule,
2313                                meta, del, add, reset);
2314                return;
2315        } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
2316                   (!one->mode || S_ISGITLINK(one->mode)) &&
2317                   (!two->mode || S_ISGITLINK(two->mode))) {
2318                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
2319                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
2320                show_submodule_inline_diff(o->file, one->path ? one->path : two->path,
2321                                line_prefix,
2322                                &one->oid, &two->oid,
2323                                two->dirty_submodule,
2324                                meta, del, add, reset, o);
2325                return;
2326        }
2327
2328        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
2329                textconv_one = get_textconv(one);
2330                textconv_two = get_textconv(two);
2331        }
2332
2333        /* Never use a non-valid filename anywhere if at all possible */
2334        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
2335        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
2336
2337        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
2338        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
2339        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
2340        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
2341        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, meta, a_one, b_two, reset);
2342        if (lbl[0][0] == '/') {
2343                /* /dev/null */
2344                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, meta, two->mode, reset);
2345                if (xfrm_msg)
2346                        strbuf_addstr(&header, xfrm_msg);
2347                must_show_header = 1;
2348        }
2349        else if (lbl[1][0] == '/') {
2350                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, meta, one->mode, reset);
2351                if (xfrm_msg)
2352                        strbuf_addstr(&header, xfrm_msg);
2353                must_show_header = 1;
2354        }
2355        else {
2356                if (one->mode != two->mode) {
2357                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, meta, one->mode, reset);
2358                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, meta, two->mode, reset);
2359                        must_show_header = 1;
2360                }
2361                if (xfrm_msg)
2362                        strbuf_addstr(&header, xfrm_msg);
2363
2364                /*
2365                 * we do not run diff between different kind
2366                 * of objects.
2367                 */
2368                if ((one->mode ^ two->mode) & S_IFMT)
2369                        goto free_ab_and_return;
2370                if (complete_rewrite &&
2371                    (textconv_one || !diff_filespec_is_binary(one)) &&
2372                    (textconv_two || !diff_filespec_is_binary(two))) {
2373                        fprintf(o->file, "%s", header.buf);
2374                        strbuf_reset(&header);
2375                        emit_rewrite_diff(name_a, name_b, one, two,
2376                                                textconv_one, textconv_two, o);
2377                        o->found_changes = 1;
2378                        goto free_ab_and_return;
2379                }
2380        }
2381
2382        if (o->irreversible_delete && lbl[1][0] == '/') {
2383                fprintf(o->file, "%s", header.buf);
2384                strbuf_reset(&header);
2385                goto free_ab_and_return;
2386        } else if (!DIFF_OPT_TST(o, TEXT) &&
2387            ( (!textconv_one && diff_filespec_is_binary(one)) ||
2388              (!textconv_two && diff_filespec_is_binary(two)) )) {
2389                if (!one->data && !two->data &&
2390                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
2391                    !DIFF_OPT_TST(o, BINARY)) {
2392                        if (!oidcmp(&one->oid, &two->oid)) {
2393                                if (must_show_header)
2394                                        fprintf(o->file, "%s", header.buf);
2395                                goto free_ab_and_return;
2396                        }
2397                        fprintf(o->file, "%s", header.buf);
2398                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2399                                line_prefix, lbl[0], lbl[1]);
2400                        goto free_ab_and_return;
2401                }
2402                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2403                        die("unable to read files to diff");
2404                /* Quite common confusing case */
2405                if (mf1.size == mf2.size &&
2406                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
2407                        if (must_show_header)
2408                                fprintf(o->file, "%s", header.buf);
2409                        goto free_ab_and_return;
2410                }
2411                fprintf(o->file, "%s", header.buf);
2412                strbuf_reset(&header);
2413                if (DIFF_OPT_TST(o, BINARY))
2414                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
2415                else
2416                        fprintf(o->file, "%sBinary files %s and %s differ\n",
2417                                line_prefix, lbl[0], lbl[1]);
2418                o->found_changes = 1;
2419        } else {
2420                /* Crazy xdl interfaces.. */
2421                const char *diffopts = getenv("GIT_DIFF_OPTS");
2422                const char *v;
2423                xpparam_t xpp;
2424                xdemitconf_t xecfg;
2425                struct emit_callback ecbdata;
2426                const struct userdiff_funcname *pe;
2427
2428                if (must_show_header) {
2429                        fprintf(o->file, "%s", header.buf);
2430                        strbuf_reset(&header);
2431                }
2432
2433                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
2434                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
2435
2436                pe = diff_funcname_pattern(one);
2437                if (!pe)
2438                        pe = diff_funcname_pattern(two);
2439
2440                memset(&xpp, 0, sizeof(xpp));
2441                memset(&xecfg, 0, sizeof(xecfg));
2442                memset(&ecbdata, 0, sizeof(ecbdata));
2443                ecbdata.label_path = lbl;
2444                ecbdata.color_diff = want_color(o->use_color);
2445                ecbdata.ws_rule = whitespace_rule(name_b);
2446                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
2447                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2448                ecbdata.opt = o;
2449                ecbdata.header = header.len ? &header : NULL;
2450                xpp.flags = o->xdl_opts;
2451                xecfg.ctxlen = o->context;
2452                xecfg.interhunkctxlen = o->interhunkcontext;
2453                xecfg.flags = XDL_EMIT_FUNCNAMES;
2454                if (DIFF_OPT_TST(o, FUNCCONTEXT))
2455                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
2456                if (pe)
2457                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
2458                if (!diffopts)
2459                        ;
2460                else if (skip_prefix(diffopts, "--unified=", &v))
2461                        xecfg.ctxlen = strtoul(v, NULL, 10);
2462                else if (skip_prefix(diffopts, "-u", &v))
2463                        xecfg.ctxlen = strtoul(v, NULL, 10);
2464                if (o->word_diff)
2465                        init_diff_words_data(&ecbdata, o, one, two);
2466                if (xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2467                                  &xpp, &xecfg))
2468                        die("unable to generate diff for %s", one->path);
2469                if (o->word_diff)
2470                        free_diff_words_data(&ecbdata);
2471                if (textconv_one)
2472                        free(mf1.ptr);
2473                if (textconv_two)
2474                        free(mf2.ptr);
2475                xdiff_clear_find_func(&xecfg);
2476        }
2477
2478 free_ab_and_return:
2479        strbuf_release(&header);
2480        diff_free_filespec_data(one);
2481        diff_free_filespec_data(two);
2482        free(a_one);
2483        free(b_two);
2484        return;
2485}
2486
2487static void builtin_diffstat(const char *name_a, const char *name_b,
2488                             struct diff_filespec *one,
2489                             struct diff_filespec *two,
2490                             struct diffstat_t *diffstat,
2491                             struct diff_options *o,
2492                             struct diff_filepair *p)
2493{
2494        mmfile_t mf1, mf2;
2495        struct diffstat_file *data;
2496        int same_contents;
2497        int complete_rewrite = 0;
2498
2499        if (!DIFF_PAIR_UNMERGED(p)) {
2500                if (p->status == DIFF_STATUS_MODIFIED && p->score)
2501                        complete_rewrite = 1;
2502        }
2503
2504        data = diffstat_add(diffstat, name_a, name_b);
2505        data->is_interesting = p->status != DIFF_STATUS_UNKNOWN;
2506
2507        if (!one || !two) {
2508                data->is_unmerged = 1;
2509                return;
2510        }
2511
2512        same_contents = !oidcmp(&one->oid, &two->oid);
2513
2514        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2515                data->is_binary = 1;
2516                if (same_contents) {
2517                        data->added = 0;
2518                        data->deleted = 0;
2519                } else {
2520                        data->added = diff_filespec_size(two);
2521                        data->deleted = diff_filespec_size(one);
2522                }
2523        }
2524
2525        else if (complete_rewrite) {
2526                diff_populate_filespec(one, 0);
2527                diff_populate_filespec(two, 0);
2528                data->deleted = count_lines(one->data, one->size);
2529                data->added = count_lines(two->data, two->size);
2530        }
2531
2532        else if (!same_contents) {
2533                /* Crazy xdl interfaces.. */
2534                xpparam_t xpp;
2535                xdemitconf_t xecfg;
2536
2537                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2538                        die("unable to read files to diff");
2539
2540                memset(&xpp, 0, sizeof(xpp));
2541                memset(&xecfg, 0, sizeof(xecfg));
2542                xpp.flags = o->xdl_opts;
2543                xecfg.ctxlen = o->context;
2544                xecfg.interhunkctxlen = o->interhunkcontext;
2545                if (xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2546                                  &xpp, &xecfg))
2547                        die("unable to generate diffstat for %s", one->path);
2548        }
2549
2550        diff_free_filespec_data(one);
2551        diff_free_filespec_data(two);
2552}
2553
2554static void builtin_checkdiff(const char *name_a, const char *name_b,
2555                              const char *attr_path,
2556                              struct diff_filespec *one,
2557                              struct diff_filespec *two,
2558                              struct diff_options *o)
2559{
2560        mmfile_t mf1, mf2;
2561        struct checkdiff_t data;
2562
2563        if (!two)
2564                return;
2565
2566        memset(&data, 0, sizeof(data));
2567        data.filename = name_b ? name_b : name_a;
2568        data.lineno = 0;
2569        data.o = o;
2570        data.ws_rule = whitespace_rule(attr_path);
2571        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2572
2573        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2574                die("unable to read files to diff");
2575
2576        /*
2577         * All the other codepaths check both sides, but not checking
2578         * the "old" side here is deliberate.  We are checking the newly
2579         * introduced changes, and as long as the "new" side is text, we
2580         * can and should check what it introduces.
2581         */
2582        if (diff_filespec_is_binary(two))
2583                goto free_and_return;
2584        else {
2585                /* Crazy xdl interfaces.. */
2586                xpparam_t xpp;
2587                xdemitconf_t xecfg;
2588
2589                memset(&xpp, 0, sizeof(xpp));
2590                memset(&xecfg, 0, sizeof(xecfg));
2591                xecfg.ctxlen = 1; /* at least one context line */
2592                xpp.flags = 0;
2593                if (xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2594                                  &xpp, &xecfg))
2595                        die("unable to generate checkdiff for %s", one->path);
2596
2597                if (data.ws_rule & WS_BLANK_AT_EOF) {
2598                        struct emit_callback ecbdata;
2599                        int blank_at_eof;
2600
2601                        ecbdata.ws_rule = data.ws_rule;
2602                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2603                        blank_at_eof = ecbdata.blank_at_eof_in_postimage;
2604
2605                        if (blank_at_eof) {
2606                                static char *err;
2607                                if (!err)
2608                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2609                                fprintf(o->file, "%s:%d: %s.\n",
2610                                        data.filename, blank_at_eof, err);
2611                                data.status = 1; /* report errors */
2612                        }
2613                }
2614        }
2615 free_and_return:
2616        diff_free_filespec_data(one);
2617        diff_free_filespec_data(two);
2618        if (data.status)
2619                DIFF_OPT_SET(o, CHECK_FAILED);
2620}
2621
2622struct diff_filespec *alloc_filespec(const char *path)
2623{
2624        struct diff_filespec *spec;
2625
2626        FLEXPTR_ALLOC_STR(spec, path, path);
2627        spec->count = 1;
2628        spec->is_binary = -1;
2629        return spec;
2630}
2631
2632void free_filespec(struct diff_filespec *spec)
2633{
2634        if (!--spec->count) {
2635                diff_free_filespec_data(spec);
2636                free(spec);
2637        }
2638}
2639
2640void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2641                   int sha1_valid, unsigned short mode)
2642{
2643        if (mode) {
2644                spec->mode = canon_mode(mode);
2645                hashcpy(spec->oid.hash, sha1);
2646                spec->oid_valid = sha1_valid;
2647        }
2648}
2649
2650/*
2651 * Given a name and sha1 pair, if the index tells us the file in
2652 * the work tree has that object contents, return true, so that
2653 * prepare_temp_file() does not have to inflate and extract.
2654 */
2655static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2656{
2657        const struct cache_entry *ce;
2658        struct stat st;
2659        int pos, len;
2660
2661        /*
2662         * We do not read the cache ourselves here, because the
2663         * benchmark with my previous version that always reads cache
2664         * shows that it makes things worse for diff-tree comparing
2665         * two linux-2.6 kernel trees in an already checked out work
2666         * tree.  This is because most diff-tree comparisons deal with
2667         * only a small number of files, while reading the cache is
2668         * expensive for a large project, and its cost outweighs the
2669         * savings we get by not inflating the object to a temporary
2670         * file.  Practically, this code only helps when we are used
2671         * by diff-cache --cached, which does read the cache before
2672         * calling us.
2673         */
2674        if (!active_cache)
2675                return 0;
2676
2677        /* We want to avoid the working directory if our caller
2678         * doesn't need the data in a normal file, this system
2679         * is rather slow with its stat/open/mmap/close syscalls,
2680         * and the object is contained in a pack file.  The pack
2681         * is probably already open and will be faster to obtain
2682         * the data through than the working directory.  Loose
2683         * objects however would tend to be slower as they need
2684         * to be individually opened and inflated.
2685         */
2686        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2687                return 0;
2688
2689        /*
2690         * Similarly, if we'd have to convert the file contents anyway, that
2691         * makes the optimization not worthwhile.
2692         */
2693        if (!want_file && would_convert_to_git(name))
2694                return 0;
2695
2696        len = strlen(name);
2697        pos = cache_name_pos(name, len);
2698        if (pos < 0)
2699                return 0;
2700        ce = active_cache[pos];
2701
2702        /*
2703         * This is not the sha1 we are looking for, or
2704         * unreusable because it is not a regular file.
2705         */
2706        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2707                return 0;
2708
2709        /*
2710         * If ce is marked as "assume unchanged", there is no
2711         * guarantee that work tree matches what we are looking for.
2712         */
2713        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2714                return 0;
2715
2716        /*
2717         * If ce matches the file in the work tree, we can reuse it.
2718         */
2719        if (ce_uptodate(ce) ||
2720            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2721                return 1;
2722
2723        return 0;
2724}
2725
2726static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2727{
2728        struct strbuf buf = STRBUF_INIT;
2729        char *dirty = "";
2730
2731        /* Are we looking at the work tree? */
2732        if (s->dirty_submodule)
2733                dirty = "-dirty";
2734
2735        strbuf_addf(&buf, "Subproject commit %s%s\n",
2736                    oid_to_hex(&s->oid), dirty);
2737        s->size = buf.len;
2738        if (size_only) {
2739                s->data = NULL;
2740                strbuf_release(&buf);
2741        } else {
2742                s->data = strbuf_detach(&buf, NULL);
2743                s->should_free = 1;
2744        }
2745        return 0;
2746}
2747
2748/*
2749 * While doing rename detection and pickaxe operation, we may need to
2750 * grab the data for the blob (or file) for our own in-core comparison.
2751 * diff_filespec has data and size fields for this purpose.
2752 */
2753int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
2754{
2755        int size_only = flags & CHECK_SIZE_ONLY;
2756        int err = 0;
2757        /*
2758         * demote FAIL to WARN to allow inspecting the situation
2759         * instead of refusing.
2760         */
2761        enum safe_crlf crlf_warn = (safe_crlf == SAFE_CRLF_FAIL
2762                                    ? SAFE_CRLF_WARN
2763                                    : safe_crlf);
2764
2765        if (!DIFF_FILE_VALID(s))
2766                die("internal error: asking to populate invalid file.");
2767        if (S_ISDIR(s->mode))
2768                return -1;
2769
2770        if (s->data)
2771                return 0;
2772
2773        if (size_only && 0 < s->size)
2774                return 0;
2775
2776        if (S_ISGITLINK(s->mode))
2777                return diff_populate_gitlink(s, size_only);
2778
2779        if (!s->oid_valid ||
2780            reuse_worktree_file(s->path, s->oid.hash, 0)) {
2781                struct strbuf buf = STRBUF_INIT;
2782                struct stat st;
2783                int fd;
2784
2785                if (lstat(s->path, &st) < 0) {
2786                        if (errno == ENOENT) {
2787                        err_empty:
2788                                err = -1;
2789                        empty:
2790                                s->data = (char *)"";
2791                                s->size = 0;
2792                                return err;
2793                        }
2794                }
2795                s->size = xsize_t(st.st_size);
2796                if (!s->size)
2797                        goto empty;
2798                if (S_ISLNK(st.st_mode)) {
2799                        struct strbuf sb = STRBUF_INIT;
2800
2801                        if (strbuf_readlink(&sb, s->path, s->size))
2802                                goto err_empty;
2803                        s->size = sb.len;
2804                        s->data = strbuf_detach(&sb, NULL);
2805                        s->should_free = 1;
2806                        return 0;
2807                }
2808                if (size_only)
2809                        return 0;
2810                if ((flags & CHECK_BINARY) &&
2811                    s->size > big_file_threshold && s->is_binary == -1) {
2812                        s->is_binary = 1;
2813                        return 0;
2814                }
2815                fd = open(s->path, O_RDONLY);
2816                if (fd < 0)
2817                        goto err_empty;
2818                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2819                close(fd);
2820                s->should_munmap = 1;
2821
2822                /*
2823                 * Convert from working tree format to canonical git format
2824                 */
2825                if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
2826                        size_t size = 0;
2827                        munmap(s->data, s->size);
2828                        s->should_munmap = 0;
2829                        s->data = strbuf_detach(&buf, &size);
2830                        s->size = size;
2831                        s->should_free = 1;
2832                }
2833        }
2834        else {
2835                enum object_type type;
2836                if (size_only || (flags & CHECK_BINARY)) {
2837                        type = sha1_object_info(s->oid.hash, &s->size);
2838                        if (type < 0)
2839                                die("unable to read %s",
2840                                    oid_to_hex(&s->oid));
2841                        if (size_only)
2842                                return 0;
2843                        if (s->size > big_file_threshold && s->is_binary == -1) {
2844                                s->is_binary = 1;
2845                                return 0;
2846                        }
2847                }
2848                s->data = read_sha1_file(s->oid.hash, &type, &s->size);
2849                if (!s->data)
2850                        die("unable to read %s", oid_to_hex(&s->oid));
2851                s->should_free = 1;
2852        }
2853        return 0;
2854}
2855
2856void diff_free_filespec_blob(struct diff_filespec *s)
2857{
2858        if (s->should_free)
2859                free(s->data);
2860        else if (s->should_munmap)
2861                munmap(s->data, s->size);
2862
2863        if (s->should_free || s->should_munmap) {
2864                s->should_free = s->should_munmap = 0;
2865                s->data = NULL;
2866        }
2867}
2868
2869void diff_free_filespec_data(struct diff_filespec *s)
2870{
2871        diff_free_filespec_blob(s);
2872        free(s->cnt_data);
2873        s->cnt_data = NULL;
2874}
2875
2876static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2877                           void *blob,
2878                           unsigned long size,
2879                           const struct object_id *oid,
2880                           int mode)
2881{
2882        int fd;
2883        struct strbuf buf = STRBUF_INIT;
2884        struct strbuf template = STRBUF_INIT;
2885        char *path_dup = xstrdup(path);
2886        const char *base = basename(path_dup);
2887
2888        /* Generate "XXXXXX_basename.ext" */
2889        strbuf_addstr(&template, "XXXXXX_");
2890        strbuf_addstr(&template, base);
2891
2892        fd = mks_tempfile_ts(&temp->tempfile, template.buf, strlen(base) + 1);
2893        if (fd < 0)
2894                die_errno("unable to create temp-file");
2895        if (convert_to_working_tree(path,
2896                        (const char *)blob, (size_t)size, &buf)) {
2897                blob = buf.buf;
2898                size = buf.len;
2899        }
2900        if (write_in_full(fd, blob, size) != size)
2901                die_errno("unable to write temp-file");
2902        close_tempfile(&temp->tempfile);
2903        temp->name = get_tempfile_path(&temp->tempfile);
2904        oid_to_hex_r(temp->hex, oid);
2905        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", mode);
2906        strbuf_release(&buf);
2907        strbuf_release(&template);
2908        free(path_dup);
2909}
2910
2911static struct diff_tempfile *prepare_temp_file(const char *name,
2912                struct diff_filespec *one)
2913{
2914        struct diff_tempfile *temp = claim_diff_tempfile();
2915
2916        if (!DIFF_FILE_VALID(one)) {
2917        not_a_valid_file:
2918                /* A '-' entry produces this for file-2, and
2919                 * a '+' entry produces this for file-1.
2920                 */
2921                temp->name = "/dev/null";
2922                xsnprintf(temp->hex, sizeof(temp->hex), ".");
2923                xsnprintf(temp->mode, sizeof(temp->mode), ".");
2924                return temp;
2925        }
2926
2927        if (!S_ISGITLINK(one->mode) &&
2928            (!one->oid_valid ||
2929             reuse_worktree_file(name, one->oid.hash, 1))) {
2930                struct stat st;
2931                if (lstat(name, &st) < 0) {
2932                        if (errno == ENOENT)
2933                                goto not_a_valid_file;
2934                        die_errno("stat(%s)", name);
2935                }
2936                if (S_ISLNK(st.st_mode)) {
2937                        struct strbuf sb = STRBUF_INIT;
2938                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2939                                die_errno("readlink(%s)", name);
2940                        prep_temp_blob(name, temp, sb.buf, sb.len,
2941                                       (one->oid_valid ?
2942                                        &one->oid : &null_oid),
2943                                       (one->oid_valid ?
2944                                        one->mode : S_IFLNK));
2945                        strbuf_release(&sb);
2946                }
2947                else {
2948                        /* we can borrow from the file in the work tree */
2949                        temp->name = name;
2950                        if (!one->oid_valid)
2951                                sha1_to_hex_r(temp->hex, null_sha1);
2952                        else
2953                                sha1_to_hex_r(temp->hex, one->oid.hash);
2954                        /* Even though we may sometimes borrow the
2955                         * contents from the work tree, we always want
2956                         * one->mode.  mode is trustworthy even when
2957                         * !(one->sha1_valid), as long as
2958                         * DIFF_FILE_VALID(one).
2959                         */
2960                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
2961                }
2962                return temp;
2963        }
2964        else {
2965                if (diff_populate_filespec(one, 0))
2966                        die("cannot read data blob for %s", one->path);
2967                prep_temp_blob(name, temp, one->data, one->size,
2968                               &one->oid, one->mode);
2969        }
2970        return temp;
2971}
2972
2973static void add_external_diff_name(struct argv_array *argv,
2974                                   const char *name,
2975                                   struct diff_filespec *df)
2976{
2977        struct diff_tempfile *temp = prepare_temp_file(name, df);
2978        argv_array_push(argv, temp->name);
2979        argv_array_push(argv, temp->hex);
2980        argv_array_push(argv, temp->mode);
2981}
2982
2983/* An external diff command takes:
2984 *
2985 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2986 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2987 *
2988 */
2989static void run_external_diff(const char *pgm,
2990                              const char *name,
2991                              const char *other,
2992                              struct diff_filespec *one,
2993                              struct diff_filespec *two,
2994                              const char *xfrm_msg,
2995                              int complete_rewrite,
2996                              struct diff_options *o)
2997{
2998        struct argv_array argv = ARGV_ARRAY_INIT;
2999        struct argv_array env = ARGV_ARRAY_INIT;
3000        struct diff_queue_struct *q = &diff_queued_diff;
3001
3002        argv_array_push(&argv, pgm);
3003        argv_array_push(&argv, name);
3004
3005        if (one && two) {
3006                add_external_diff_name(&argv, name, one);
3007                if (!other)
3008                        add_external_diff_name(&argv, name, two);
3009                else {
3010                        add_external_diff_name(&argv, other, two);
3011                        argv_array_push(&argv, other);
3012                        argv_array_push(&argv, xfrm_msg);
3013                }
3014        }
3015
3016        argv_array_pushf(&env, "GIT_DIFF_PATH_COUNTER=%d", ++o->diff_path_counter);
3017        argv_array_pushf(&env, "GIT_DIFF_PATH_TOTAL=%d", q->nr);
3018
3019        if (run_command_v_opt_cd_env(argv.argv, RUN_USING_SHELL, NULL, env.argv))
3020                die(_("external diff died, stopping at %s"), name);
3021
3022        remove_tempfile();
3023        argv_array_clear(&argv);
3024        argv_array_clear(&env);
3025}
3026
3027static int similarity_index(struct diff_filepair *p)
3028{
3029        return p->score * 100 / MAX_SCORE;
3030}
3031
3032static void fill_metainfo(struct strbuf *msg,
3033                          const char *name,
3034                          const char *other,
3035                          struct diff_filespec *one,
3036                          struct diff_filespec *two,
3037                          struct diff_options *o,
3038                          struct diff_filepair *p,
3039                          int *must_show_header,
3040                          int use_color)
3041{
3042        const char *set = diff_get_color(use_color, DIFF_METAINFO);
3043        const char *reset = diff_get_color(use_color, DIFF_RESET);
3044        const char *line_prefix = diff_line_prefix(o);
3045
3046        *must_show_header = 1;
3047        strbuf_init(msg, PATH_MAX * 2 + 300);
3048        switch (p->status) {
3049        case DIFF_STATUS_COPIED:
3050                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3051                            line_prefix, set, similarity_index(p));
3052                strbuf_addf(msg, "%s\n%s%scopy from ",
3053                            reset,  line_prefix, set);
3054                quote_c_style(name, msg, NULL, 0);
3055                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
3056                quote_c_style(other, msg, NULL, 0);
3057                strbuf_addf(msg, "%s\n", reset);
3058                break;
3059        case DIFF_STATUS_RENAMED:
3060                strbuf_addf(msg, "%s%ssimilarity index %d%%",
3061                            line_prefix, set, similarity_index(p));
3062                strbuf_addf(msg, "%s\n%s%srename from ",
3063                            reset, line_prefix, set);
3064                quote_c_style(name, msg, NULL, 0);
3065                strbuf_addf(msg, "%s\n%s%srename to ",
3066                            reset, line_prefix, set);
3067                quote_c_style(other, msg, NULL, 0);
3068                strbuf_addf(msg, "%s\n", reset);
3069                break;
3070        case DIFF_STATUS_MODIFIED:
3071                if (p->score) {
3072                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
3073                                    line_prefix,
3074                                    set, similarity_index(p), reset);
3075                        break;
3076                }
3077                /* fallthru */
3078        default:
3079                *must_show_header = 0;
3080        }
3081        if (one && two && oidcmp(&one->oid, &two->oid)) {
3082                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
3083
3084                if (DIFF_OPT_TST(o, BINARY)) {
3085                        mmfile_t mf;
3086                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
3087                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
3088                                abbrev = 40;
3089                }
3090                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
3091                            find_unique_abbrev(one->oid.hash, abbrev));
3092                strbuf_addstr(msg, find_unique_abbrev(two->oid.hash, abbrev));
3093                if (one->mode == two->mode)
3094                        strbuf_addf(msg, " %06o", one->mode);
3095                strbuf_addf(msg, "%s\n", reset);
3096        }
3097}
3098
3099static void run_diff_cmd(const char *pgm,
3100                         const char *name,
3101                         const char *other,
3102                         const char *attr_path,
3103                         struct diff_filespec *one,
3104                         struct diff_filespec *two,
3105                         struct strbuf *msg,
3106                         struct diff_options *o,
3107                         struct diff_filepair *p)
3108{
3109        const char *xfrm_msg = NULL;
3110        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
3111        int must_show_header = 0;
3112
3113
3114        if (DIFF_OPT_TST(o, ALLOW_EXTERNAL)) {
3115                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
3116                if (drv && drv->external)
3117                        pgm = drv->external;
3118        }
3119
3120        if (msg) {
3121                /*
3122                 * don't use colors when the header is intended for an
3123                 * external diff driver
3124                 */
3125                fill_metainfo(msg, name, other, one, two, o, p,
3126                              &must_show_header,
3127                              want_color(o->use_color) && !pgm);
3128                xfrm_msg = msg->len ? msg->buf : NULL;
3129        }
3130
3131        if (pgm) {
3132                run_external_diff(pgm, name, other, one, two, xfrm_msg,
3133                                  complete_rewrite, o);
3134                return;
3135        }
3136        if (one && two)
3137                builtin_diff(name, other ? other : name,
3138                             one, two, xfrm_msg, must_show_header,
3139                             o, complete_rewrite);
3140        else
3141                fprintf(o->file, "* Unmerged path %s\n", name);
3142}
3143
3144static void diff_fill_sha1_info(struct diff_filespec *one)
3145{
3146        if (DIFF_FILE_VALID(one)) {
3147                if (!one->oid_valid) {
3148                        struct stat st;
3149                        if (one->is_stdin) {
3150                                oidclr(&one->oid);
3151                                return;
3152                        }
3153                        if (lstat(one->path, &st) < 0)
3154                                die_errno("stat '%s'", one->path);
3155                        if (index_path(one->oid.hash, one->path, &st, 0))
3156                                die("cannot hash %s", one->path);
3157                }
3158        }
3159        else
3160                oidclr(&one->oid);
3161}
3162
3163static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
3164{
3165        /* Strip the prefix but do not molest /dev/null and absolute paths */
3166        if (*namep && **namep != '/') {
3167                *namep += prefix_length;
3168                if (**namep == '/')
3169                        ++*namep;
3170        }
3171        if (*otherp && **otherp != '/') {
3172                *otherp += prefix_length;
3173                if (**otherp == '/')
3174                        ++*otherp;
3175        }
3176}
3177
3178static void run_diff(struct diff_filepair *p, struct diff_options *o)
3179{
3180        const char *pgm = external_diff();
3181        struct strbuf msg;
3182        struct diff_filespec *one = p->one;
3183        struct diff_filespec *two = p->two;
3184        const char *name;
3185        const char *other;
3186        const char *attr_path;
3187
3188        name  = p->one->path;
3189        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3190        attr_path = name;
3191        if (o->prefix_length)
3192                strip_prefix(o->prefix_length, &name, &other);
3193
3194        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
3195                pgm = NULL;
3196
3197        if (DIFF_PAIR_UNMERGED(p)) {
3198                run_diff_cmd(pgm, name, NULL, attr_path,
3199                             NULL, NULL, NULL, o, p);
3200                return;
3201        }
3202
3203        diff_fill_sha1_info(one);
3204        diff_fill_sha1_info(two);
3205
3206        if (!pgm &&
3207            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
3208            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
3209                /*
3210                 * a filepair that changes between file and symlink
3211                 * needs to be split into deletion and creation.
3212                 */
3213                struct diff_filespec *null = alloc_filespec(two->path);
3214                run_diff_cmd(NULL, name, other, attr_path,
3215                             one, null, &msg, o, p);
3216                free(null);
3217                strbuf_release(&msg);
3218
3219                null = alloc_filespec(one->path);
3220                run_diff_cmd(NULL, name, other, attr_path,
3221                             null, two, &msg, o, p);
3222                free(null);
3223        }
3224        else
3225                run_diff_cmd(pgm, name, other, attr_path,
3226                             one, two, &msg, o, p);
3227
3228        strbuf_release(&msg);
3229}
3230
3231static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
3232                         struct diffstat_t *diffstat)
3233{
3234        const char *name;
3235        const char *other;
3236
3237        if (DIFF_PAIR_UNMERGED(p)) {
3238                /* unmerged */
3239                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, p);
3240                return;
3241        }
3242
3243        name = p->one->path;
3244        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3245
3246        if (o->prefix_length)
3247                strip_prefix(o->prefix_length, &name, &other);
3248
3249        diff_fill_sha1_info(p->one);
3250        diff_fill_sha1_info(p->two);
3251
3252        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
3253}
3254
3255static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
3256{
3257        const char *name;
3258        const char *other;
3259        const char *attr_path;
3260
3261        if (DIFF_PAIR_UNMERGED(p)) {
3262                /* unmerged */
3263                return;
3264        }
3265
3266        name = p->one->path;
3267        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
3268        attr_path = other ? other : name;
3269
3270        if (o->prefix_length)
3271                strip_prefix(o->prefix_length, &name, &other);
3272
3273        diff_fill_sha1_info(p->one);
3274        diff_fill_sha1_info(p->two);
3275
3276        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
3277}
3278
3279void diff_setup(struct diff_options *options)
3280{
3281        memcpy(options, &default_diff_options, sizeof(*options));
3282
3283        options->file = stdout;
3284
3285        options->line_termination = '\n';
3286        options->break_opt = -1;
3287        options->rename_limit = -1;
3288        options->dirstat_permille = diff_dirstat_permille_default;
3289        options->context = diff_context_default;
3290        options->ws_error_highlight = WSEH_NEW;
3291        DIFF_OPT_SET(options, RENAME_EMPTY);
3292
3293        /* pathchange left =NULL by default */
3294        options->change = diff_change;
3295        options->add_remove = diff_addremove;
3296        options->use_color = diff_use_color_default;
3297        options->detect_rename = diff_detect_rename_default;
3298        options->xdl_opts |= diff_algorithm;
3299        if (diff_compaction_heuristic)
3300                DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
3301
3302        options->orderfile = diff_order_file_cfg;
3303
3304        if (diff_no_prefix) {
3305                options->a_prefix = options->b_prefix = "";
3306        } else if (!diff_mnemonic_prefix) {
3307                options->a_prefix = "a/";
3308                options->b_prefix = "b/";
3309        }
3310}
3311
3312void diff_setup_done(struct diff_options *options)
3313{
3314        int count = 0;
3315
3316        if (options->set_default)
3317                options->set_default(options);
3318
3319        if (options->output_format & DIFF_FORMAT_NAME)
3320                count++;
3321        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
3322                count++;
3323        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
3324                count++;
3325        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
3326                count++;
3327        if (count > 1)
3328                die("--name-only, --name-status, --check and -s are mutually exclusive");
3329
3330        /*
3331         * Most of the time we can say "there are changes"
3332         * only by checking if there are changed paths, but
3333         * --ignore-whitespace* options force us to look
3334         * inside contents.
3335         */
3336
3337        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
3338            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
3339            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
3340                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
3341        else
3342                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
3343
3344        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3345                options->detect_rename = DIFF_DETECT_COPY;
3346
3347        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
3348                options->prefix = NULL;
3349        if (options->prefix)
3350                options->prefix_length = strlen(options->prefix);
3351        else
3352                options->prefix_length = 0;
3353
3354        if (options->output_format & (DIFF_FORMAT_NAME |
3355                                      DIFF_FORMAT_NAME_STATUS |
3356                                      DIFF_FORMAT_CHECKDIFF |
3357                                      DIFF_FORMAT_NO_OUTPUT))
3358                options->output_format &= ~(DIFF_FORMAT_RAW |
3359                                            DIFF_FORMAT_NUMSTAT |
3360                                            DIFF_FORMAT_DIFFSTAT |
3361                                            DIFF_FORMAT_SHORTSTAT |
3362                                            DIFF_FORMAT_DIRSTAT |
3363                                            DIFF_FORMAT_SUMMARY |
3364                                            DIFF_FORMAT_PATCH);
3365
3366        /*
3367         * These cases always need recursive; we do not drop caller-supplied
3368         * recursive bits for other formats here.
3369         */
3370        if (options->output_format & (DIFF_FORMAT_PATCH |
3371                                      DIFF_FORMAT_NUMSTAT |
3372                                      DIFF_FORMAT_DIFFSTAT |
3373                                      DIFF_FORMAT_SHORTSTAT |
3374                                      DIFF_FORMAT_DIRSTAT |
3375                                      DIFF_FORMAT_SUMMARY |
3376                                      DIFF_FORMAT_CHECKDIFF))
3377                DIFF_OPT_SET(options, RECURSIVE);
3378        /*
3379         * Also pickaxe would not work very well if you do not say recursive
3380         */
3381        if (options->pickaxe)
3382                DIFF_OPT_SET(options, RECURSIVE);
3383        /*
3384         * When patches are generated, submodules diffed against the work tree
3385         * must be checked for dirtiness too so it can be shown in the output
3386         */
3387        if (options->output_format & DIFF_FORMAT_PATCH)
3388                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
3389
3390        if (options->detect_rename && options->rename_limit < 0)
3391                options->rename_limit = diff_rename_limit_default;
3392        if (options->setup & DIFF_SETUP_USE_CACHE) {
3393                if (!active_cache)
3394                        /* read-cache does not die even when it fails
3395                         * so it is safe for us to do this here.  Also
3396                         * it does not smudge active_cache or active_nr
3397                         * when it fails, so we do not have to worry about
3398                         * cleaning it up ourselves either.
3399                         */
3400                        read_cache();
3401        }
3402        if (options->abbrev <= 0 || 40 < options->abbrev)
3403                options->abbrev = 40; /* full */
3404
3405        /*
3406         * It does not make sense to show the first hit we happened
3407         * to have found.  It does not make sense not to return with
3408         * exit code in such a case either.
3409         */
3410        if (DIFF_OPT_TST(options, QUICK)) {
3411                options->output_format = DIFF_FORMAT_NO_OUTPUT;
3412                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3413        }
3414
3415        options->diff_path_counter = 0;
3416
3417        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
3418                die(_("--follow requires exactly one pathspec"));
3419}
3420
3421static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
3422{
3423        char c, *eq;
3424        int len;
3425
3426        if (*arg != '-')
3427                return 0;
3428        c = *++arg;
3429        if (!c)
3430                return 0;
3431        if (c == arg_short) {
3432                c = *++arg;
3433                if (!c)
3434                        return 1;
3435                if (val && isdigit(c)) {
3436                        char *end;
3437                        int n = strtoul(arg, &end, 10);
3438                        if (*end)
3439                                return 0;
3440                        *val = n;
3441                        return 1;
3442                }
3443                return 0;
3444        }
3445        if (c != '-')
3446                return 0;
3447        arg++;
3448        eq = strchrnul(arg, '=');
3449        len = eq - arg;
3450        if (!len || strncmp(arg, arg_long, len))
3451                return 0;
3452        if (*eq) {
3453                int n;
3454                char *end;
3455                if (!isdigit(*++eq))
3456                        return 0;
3457                n = strtoul(eq, &end, 10);
3458                if (*end)
3459                        return 0;
3460                *val = n;
3461        }
3462        return 1;
3463}
3464
3465static int diff_scoreopt_parse(const char *opt);
3466
3467static inline int short_opt(char opt, const char **argv,
3468                            const char **optarg)
3469{
3470        const char *arg = argv[0];
3471        if (arg[0] != '-' || arg[1] != opt)
3472                return 0;
3473        if (arg[2] != '\0') {
3474                *optarg = arg + 2;
3475                return 1;
3476        }
3477        if (!argv[1])
3478                die("Option '%c' requires a value", opt);
3479        *optarg = argv[1];
3480        return 2;
3481}
3482
3483int parse_long_opt(const char *opt, const char **argv,
3484                   const char **optarg)
3485{
3486        const char *arg = argv[0];
3487        if (!skip_prefix(arg, "--", &arg))
3488                return 0;
3489        if (!skip_prefix(arg, opt, &arg))
3490                return 0;
3491        if (*arg == '=') { /* stuck form: --option=value */
3492                *optarg = arg + 1;
3493                return 1;
3494        }
3495        if (*arg != '\0')
3496                return 0;
3497        /* separate form: --option value */
3498        if (!argv[1])
3499                die("Option '--%s' requires a value", opt);
3500        *optarg = argv[1];
3501        return 2;
3502}
3503
3504static int stat_opt(struct diff_options *options, const char **av)
3505{
3506        const char *arg = av[0];
3507        char *end;
3508        int width = options->stat_width;
3509        int name_width = options->stat_name_width;
3510        int graph_width = options->stat_graph_width;
3511        int count = options->stat_count;
3512        int argcount = 1;
3513
3514        if (!skip_prefix(arg, "--stat", &arg))
3515                die("BUG: stat option does not begin with --stat: %s", arg);
3516        end = (char *)arg;
3517
3518        switch (*arg) {
3519        case '-':
3520                if (skip_prefix(arg, "-width", &arg)) {
3521                        if (*arg == '=')
3522                                width = strtoul(arg + 1, &end, 10);
3523                        else if (!*arg && !av[1])
3524                                die("Option '--stat-width' requires a value");
3525                        else if (!*arg) {
3526                                width = strtoul(av[1], &end, 10);
3527                                argcount = 2;
3528                        }
3529                } else if (skip_prefix(arg, "-name-width", &arg)) {
3530                        if (*arg == '=')
3531                                name_width = strtoul(arg + 1, &end, 10);
3532                        else if (!*arg && !av[1])
3533                                die("Option '--stat-name-width' requires a value");
3534                        else if (!*arg) {
3535                                name_width = strtoul(av[1], &end, 10);
3536                                argcount = 2;
3537                        }
3538                } else if (skip_prefix(arg, "-graph-width", &arg)) {
3539                        if (*arg == '=')
3540                                graph_width = strtoul(arg + 1, &end, 10);
3541                        else if (!*arg && !av[1])
3542                                die("Option '--stat-graph-width' requires a value");
3543                        else if (!*arg) {
3544                                graph_width = strtoul(av[1], &end, 10);
3545                                argcount = 2;
3546                        }
3547                } else if (skip_prefix(arg, "-count", &arg)) {
3548                        if (*arg == '=')
3549                                count = strtoul(arg + 1, &end, 10);
3550                        else if (!*arg && !av[1])
3551                                die("Option '--stat-count' requires a value");
3552                        else if (!*arg) {
3553                                count = strtoul(av[1], &end, 10);
3554                                argcount = 2;
3555                        }
3556                }
3557                break;
3558        case '=':
3559                width = strtoul(arg+1, &end, 10);
3560                if (*end == ',')
3561                        name_width = strtoul(end+1, &end, 10);
3562                if (*end == ',')
3563                        count = strtoul(end+1, &end, 10);
3564        }
3565
3566        /* Important! This checks all the error cases! */
3567        if (*end)
3568                return 0;
3569        options->output_format |= DIFF_FORMAT_DIFFSTAT;
3570        options->stat_name_width = name_width;
3571        options->stat_graph_width = graph_width;
3572        options->stat_width = width;
3573        options->stat_count = count;
3574        return argcount;
3575}
3576
3577static int parse_dirstat_opt(struct diff_options *options, const char *params)
3578{
3579        struct strbuf errmsg = STRBUF_INIT;
3580        if (parse_dirstat_params(options, params, &errmsg))
3581                die(_("Failed to parse --dirstat/-X option parameter:\n%s"),
3582                    errmsg.buf);
3583        strbuf_release(&errmsg);
3584        /*
3585         * The caller knows a dirstat-related option is given from the command
3586         * line; allow it to say "return this_function();"
3587         */
3588        options->output_format |= DIFF_FORMAT_DIRSTAT;
3589        return 1;
3590}
3591
3592static int parse_submodule_opt(struct diff_options *options, const char *value)
3593{
3594        if (parse_submodule_params(options, value))
3595                die(_("Failed to parse --submodule option parameter: '%s'"),
3596                        value);
3597        return 1;
3598}
3599
3600static const char diff_status_letters[] = {
3601        DIFF_STATUS_ADDED,
3602        DIFF_STATUS_COPIED,
3603        DIFF_STATUS_DELETED,
3604        DIFF_STATUS_MODIFIED,
3605        DIFF_STATUS_RENAMED,
3606        DIFF_STATUS_TYPE_CHANGED,
3607        DIFF_STATUS_UNKNOWN,
3608        DIFF_STATUS_UNMERGED,
3609        DIFF_STATUS_FILTER_AON,
3610        DIFF_STATUS_FILTER_BROKEN,
3611        '\0',
3612};
3613
3614static unsigned int filter_bit['Z' + 1];
3615
3616static void prepare_filter_bits(void)
3617{
3618        int i;
3619
3620        if (!filter_bit[DIFF_STATUS_ADDED]) {
3621                for (i = 0; diff_status_letters[i]; i++)
3622                        filter_bit[(int) diff_status_letters[i]] = (1 << i);
3623        }
3624}
3625
3626static unsigned filter_bit_tst(char status, const struct diff_options *opt)
3627{
3628        return opt->filter & filter_bit[(int) status];
3629}
3630
3631static int parse_diff_filter_opt(const char *optarg, struct diff_options *opt)
3632{
3633        int i, optch;
3634
3635        prepare_filter_bits();
3636
3637        /*
3638         * If there is a negation e.g. 'd' in the input, and we haven't
3639         * initialized the filter field with another --diff-filter, start
3640         * from full set of bits, except for AON.
3641         */
3642        if (!opt->filter) {
3643                for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3644                        if (optch < 'a' || 'z' < optch)
3645                                continue;
3646                        opt->filter = (1 << (ARRAY_SIZE(diff_status_letters) - 1)) - 1;
3647                        opt->filter &= ~filter_bit[DIFF_STATUS_FILTER_AON];
3648                        break;
3649                }
3650        }
3651
3652        for (i = 0; (optch = optarg[i]) != '\0'; i++) {
3653                unsigned int bit;
3654                int negate;
3655
3656                if ('a' <= optch && optch <= 'z') {
3657                        negate = 1;
3658                        optch = toupper(optch);
3659                } else {
3660                        negate = 0;
3661                }
3662
3663                bit = (0 <= optch && optch <= 'Z') ? filter_bit[optch] : 0;
3664                if (!bit)
3665                        return optarg[i];
3666                if (negate)
3667                        opt->filter &= ~bit;
3668                else
3669                        opt->filter |= bit;
3670        }
3671        return 0;
3672}
3673
3674static void enable_patch_output(int *fmt) {
3675        *fmt &= ~DIFF_FORMAT_NO_OUTPUT;
3676        *fmt |= DIFF_FORMAT_PATCH;
3677}
3678
3679static int parse_one_token(const char **arg, const char *token)
3680{
3681        const char *rest;
3682        if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
3683                *arg = rest;
3684                return 1;
3685        }
3686        return 0;
3687}
3688
3689static int parse_ws_error_highlight(struct diff_options *opt, const char *arg)
3690{
3691        const char *orig_arg = arg;
3692        unsigned val = 0;
3693        while (*arg) {
3694                if (parse_one_token(&arg, "none"))
3695                        val = 0;
3696                else if (parse_one_token(&arg, "default"))
3697                        val = WSEH_NEW;
3698                else if (parse_one_token(&arg, "all"))
3699                        val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
3700                else if (parse_one_token(&arg, "new"))
3701                        val |= WSEH_NEW;
3702                else if (parse_one_token(&arg, "old"))
3703                        val |= WSEH_OLD;
3704                else if (parse_one_token(&arg, "context"))
3705                        val |= WSEH_CONTEXT;
3706                else {
3707                        error("unknown value after ws-error-highlight=%.*s",
3708                              (int)(arg - orig_arg), orig_arg);
3709                        return 0;
3710                }
3711                if (*arg)
3712                        arg++;
3713        }
3714        opt->ws_error_highlight = val;
3715        return 1;
3716}
3717
3718int diff_opt_parse(struct diff_options *options,
3719                   const char **av, int ac, const char *prefix)
3720{
3721        const char *arg = av[0];
3722        const char *optarg;
3723        int argcount;
3724
3725        if (!prefix)
3726                prefix = "";
3727
3728        /* Output format options */
3729        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch")
3730            || opt_arg(arg, 'U', "unified", &options->context))
3731                enable_patch_output(&options->output_format);
3732        else if (!strcmp(arg, "--raw"))
3733                options->output_format |= DIFF_FORMAT_RAW;
3734        else if (!strcmp(arg, "--patch-with-raw")) {
3735                enable_patch_output(&options->output_format);
3736                options->output_format |= DIFF_FORMAT_RAW;
3737        } else if (!strcmp(arg, "--numstat"))
3738                options->output_format |= DIFF_FORMAT_NUMSTAT;
3739        else if (!strcmp(arg, "--shortstat"))
3740                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3741        else if (!strcmp(arg, "-X") || !strcmp(arg, "--dirstat"))
3742                return parse_dirstat_opt(options, "");
3743        else if (skip_prefix(arg, "-X", &arg))
3744                return parse_dirstat_opt(options, arg);
3745        else if (skip_prefix(arg, "--dirstat=", &arg))
3746                return parse_dirstat_opt(options, arg);
3747        else if (!strcmp(arg, "--cumulative"))
3748                return parse_dirstat_opt(options, "cumulative");
3749        else if (!strcmp(arg, "--dirstat-by-file"))
3750                return parse_dirstat_opt(options, "files");
3751        else if (skip_prefix(arg, "--dirstat-by-file=", &arg)) {
3752                parse_dirstat_opt(options, "files");
3753                return parse_dirstat_opt(options, arg);
3754        }
3755        else if (!strcmp(arg, "--check"))
3756                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3757        else if (!strcmp(arg, "--summary"))
3758                options->output_format |= DIFF_FORMAT_SUMMARY;
3759        else if (!strcmp(arg, "--patch-with-stat")) {
3760                enable_patch_output(&options->output_format);
3761                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3762        } else if (!strcmp(arg, "--name-only"))
3763                options->output_format |= DIFF_FORMAT_NAME;
3764        else if (!strcmp(arg, "--name-status"))
3765                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3766        else if (!strcmp(arg, "-s") || !strcmp(arg, "--no-patch"))
3767                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3768        else if (starts_with(arg, "--stat"))
3769                /* --stat, --stat-width, --stat-name-width, or --stat-count */
3770                return stat_opt(options, av);
3771
3772        /* renames options */
3773        else if (starts_with(arg, "-B") || starts_with(arg, "--break-rewrites=") ||
3774                 !strcmp(arg, "--break-rewrites")) {
3775                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3776                        return error("invalid argument to -B: %s", arg+2);
3777        }
3778        else if (starts_with(arg, "-M") || starts_with(arg, "--find-renames=") ||
3779                 !strcmp(arg, "--find-renames")) {
3780                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3781                        return error("invalid argument to -M: %s", arg+2);
3782                options->detect_rename = DIFF_DETECT_RENAME;
3783        }
3784        else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
3785                options->irreversible_delete = 1;
3786        }
3787        else if (starts_with(arg, "-C") || starts_with(arg, "--find-copies=") ||
3788                 !strcmp(arg, "--find-copies")) {
3789                if (options->detect_rename == DIFF_DETECT_COPY)
3790                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3791                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3792                        return error("invalid argument to -C: %s", arg+2);
3793                options->detect_rename = DIFF_DETECT_COPY;
3794        }
3795        else if (!strcmp(arg, "--no-renames"))
3796                options->detect_rename = 0;
3797        else if (!strcmp(arg, "--rename-empty"))
3798                DIFF_OPT_SET(options, RENAME_EMPTY);
3799        else if (!strcmp(arg, "--no-rename-empty"))
3800                DIFF_OPT_CLR(options, RENAME_EMPTY);
3801        else if (!strcmp(arg, "--relative"))
3802                DIFF_OPT_SET(options, RELATIVE_NAME);
3803        else if (skip_prefix(arg, "--relative=", &arg)) {
3804                DIFF_OPT_SET(options, RELATIVE_NAME);
3805                options->prefix = arg;
3806        }
3807
3808        /* xdiff options */
3809        else if (!strcmp(arg, "--minimal"))
3810                DIFF_XDL_SET(options, NEED_MINIMAL);
3811        else if (!strcmp(arg, "--no-minimal"))
3812                DIFF_XDL_CLR(options, NEED_MINIMAL);
3813        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3814                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3815        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3816                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3817        else if (!strcmp(arg, "--ignore-space-at-eol"))
3818                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3819        else if (!strcmp(arg, "--ignore-blank-lines"))
3820                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
3821        else if (!strcmp(arg, "--compaction-heuristic"))
3822                DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
3823        else if (!strcmp(arg, "--no-compaction-heuristic"))
3824                DIFF_XDL_CLR(options, COMPACTION_HEURISTIC);
3825        else if (!strcmp(arg, "--patience"))
3826                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
3827        else if (!strcmp(arg, "--histogram"))
3828                options->xdl_opts = DIFF_WITH_ALG(options, HISTOGRAM_DIFF);
3829        else if ((argcount = parse_long_opt("diff-algorithm", av, &optarg))) {
3830                long value = parse_algorithm_value(optarg);
3831                if (value < 0)
3832                        return error("option diff-algorithm accepts \"myers\", "
3833                                     "\"minimal\", \"patience\" and \"histogram\"");
3834                /* clear out previous settings */
3835                DIFF_XDL_CLR(options, NEED_MINIMAL);
3836                options->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
3837                options->xdl_opts |= value;
3838                return argcount;
3839        }
3840
3841        /* flags options */
3842        else if (!strcmp(arg, "--binary")) {
3843                enable_patch_output(&options->output_format);
3844                DIFF_OPT_SET(options, BINARY);
3845        }
3846        else if (!strcmp(arg, "--full-index"))
3847                DIFF_OPT_SET(options, FULL_INDEX);
3848        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3849                DIFF_OPT_SET(options, TEXT);
3850        else if (!strcmp(arg, "-R"))
3851                DIFF_OPT_SET(options, REVERSE_DIFF);
3852        else if (!strcmp(arg, "--find-copies-harder"))
3853                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3854        else if (!strcmp(arg, "--follow"))
3855                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3856        else if (!strcmp(arg, "--no-follow")) {
3857                DIFF_OPT_CLR(options, FOLLOW_RENAMES);
3858                DIFF_OPT_CLR(options, DEFAULT_FOLLOW_RENAMES);
3859        } else if (!strcmp(arg, "--color"))
3860                options->use_color = 1;
3861        else if (skip_prefix(arg, "--color=", &arg)) {
3862                int value = git_config_colorbool(NULL, arg);
3863                if (value < 0)
3864                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3865                options->use_color = value;
3866        }
3867        else if (!strcmp(arg, "--no-color"))
3868                options->use_color = 0;
3869        else if (!strcmp(arg, "--color-words")) {
3870                options->use_color = 1;
3871                options->word_diff = DIFF_WORDS_COLOR;
3872        }
3873        else if (skip_prefix(arg, "--color-words=", &arg)) {
3874                options->use_color = 1;
3875                options->word_diff = DIFF_WORDS_COLOR;
3876                options->word_regex = arg;
3877        }
3878        else if (!strcmp(arg, "--word-diff")) {
3879                if (options->word_diff == DIFF_WORDS_NONE)
3880                        options->word_diff = DIFF_WORDS_PLAIN;
3881        }
3882        else if (skip_prefix(arg, "--word-diff=", &arg)) {
3883                if (!strcmp(arg, "plain"))
3884                        options->word_diff = DIFF_WORDS_PLAIN;
3885                else if (!strcmp(arg, "color")) {
3886                        options->use_color = 1;
3887                        options->word_diff = DIFF_WORDS_COLOR;
3888                }
3889                else if (!strcmp(arg, "porcelain"))
3890                        options->word_diff = DIFF_WORDS_PORCELAIN;
3891                else if (!strcmp(arg, "none"))
3892                        options->word_diff = DIFF_WORDS_NONE;
3893                else
3894                        die("bad --word-diff argument: %s", arg);
3895        }
3896        else if ((argcount = parse_long_opt("word-diff-regex", av, &optarg))) {
3897                if (options->word_diff == DIFF_WORDS_NONE)
3898                        options->word_diff = DIFF_WORDS_PLAIN;
3899                options->word_regex = optarg;
3900                return argcount;
3901        }
3902        else if (!strcmp(arg, "--exit-code"))
3903                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3904        else if (!strcmp(arg, "--quiet"))
3905                DIFF_OPT_SET(options, QUICK);
3906        else if (!strcmp(arg, "--ext-diff"))
3907                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3908        else if (!strcmp(arg, "--no-ext-diff"))
3909                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3910        else if (!strcmp(arg, "--textconv"))
3911                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3912        else if (!strcmp(arg, "--no-textconv"))
3913                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3914        else if (!strcmp(arg, "--ignore-submodules")) {
3915                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3916                handle_ignore_submodules_arg(options, "all");
3917        } else if (skip_prefix(arg, "--ignore-submodules=", &arg)) {
3918                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
3919                handle_ignore_submodules_arg(options, arg);
3920        } else if (!strcmp(arg, "--submodule"))
3921                options->submodule_format = DIFF_SUBMODULE_LOG;
3922        else if (skip_prefix(arg, "--submodule=", &arg))
3923                return parse_submodule_opt(options, arg);
3924        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
3925                return parse_ws_error_highlight(options, arg);
3926
3927        /* misc options */
3928        else if (!strcmp(arg, "-z"))
3929                options->line_termination = 0;
3930        else if ((argcount = short_opt('l', av, &optarg))) {
3931                options->rename_limit = strtoul(optarg, NULL, 10);
3932                return argcount;
3933        }
3934        else if ((argcount = short_opt('S', av, &optarg))) {
3935                options->pickaxe = optarg;
3936                options->pickaxe_opts |= DIFF_PICKAXE_KIND_S;
3937                return argcount;
3938        } else if ((argcount = short_opt('G', av, &optarg))) {
3939                options->pickaxe = optarg;
3940                options->pickaxe_opts |= DIFF_PICKAXE_KIND_G;
3941                return argcount;
3942        }
3943        else if (!strcmp(arg, "--pickaxe-all"))
3944                options->pickaxe_opts |= DIFF_PICKAXE_ALL;
3945        else if (!strcmp(arg, "--pickaxe-regex"))
3946                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
3947        else if ((argcount = short_opt('O', av, &optarg))) {
3948                const char *path = prefix_filename(prefix, strlen(prefix), optarg);
3949                options->orderfile = xstrdup(path);
3950                return argcount;
3951        }
3952        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
3953                int offending = parse_diff_filter_opt(optarg, options);
3954                if (offending)
3955                        die("unknown change class '%c' in --diff-filter=%s",
3956                            offending, optarg);
3957                return argcount;
3958        }
3959        else if (!strcmp(arg, "--abbrev"))
3960                options->abbrev = DEFAULT_ABBREV;
3961        else if (skip_prefix(arg, "--abbrev=", &arg)) {
3962                options->abbrev = strtoul(arg, NULL, 10);
3963                if (options->abbrev < MINIMUM_ABBREV)
3964                        options->abbrev = MINIMUM_ABBREV;
3965                else if (40 < options->abbrev)
3966                        options->abbrev = 40;
3967        }
3968        else if ((argcount = parse_long_opt("src-prefix", av, &optarg))) {
3969                options->a_prefix = optarg;
3970                return argcount;
3971        }
3972        else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
3973                options->line_prefix = optarg;
3974                options->line_prefix_length = strlen(options->line_prefix);
3975                graph_setup_line_prefix(options);
3976                return argcount;
3977        }
3978        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
3979                options->b_prefix = optarg;
3980                return argcount;
3981        }
3982        else if (!strcmp(arg, "--no-prefix"))
3983                options->a_prefix = options->b_prefix = "";
3984        else if (opt_arg(arg, '\0', "inter-hunk-context",
3985                         &options->interhunkcontext))
3986                ;
3987        else if (!strcmp(arg, "-W"))
3988                DIFF_OPT_SET(options, FUNCCONTEXT);
3989        else if (!strcmp(arg, "--function-context"))
3990                DIFF_OPT_SET(options, FUNCCONTEXT);
3991        else if (!strcmp(arg, "--no-function-context"))
3992                DIFF_OPT_CLR(options, FUNCCONTEXT);
3993        else if ((argcount = parse_long_opt("output", av, &optarg))) {
3994                const char *path = prefix_filename(prefix, strlen(prefix), optarg);
3995                options->file = fopen(path, "w");
3996                if (!options->file)
3997                        die_errno("Could not open '%s'", path);
3998                options->close_file = 1;
3999                if (options->use_color != GIT_COLOR_ALWAYS)
4000                        options->use_color = GIT_COLOR_NEVER;
4001                return argcount;
4002        } else
4003                return 0;
4004        return 1;
4005}
4006
4007int parse_rename_score(const char **cp_p)
4008{
4009        unsigned long num, scale;
4010        int ch, dot;
4011        const char *cp = *cp_p;
4012
4013        num = 0;
4014        scale = 1;
4015        dot = 0;
4016        for (;;) {
4017                ch = *cp;
4018                if ( !dot && ch == '.' ) {
4019                        scale = 1;
4020                        dot = 1;
4021                } else if ( ch == '%' ) {
4022                        scale = dot ? scale*100 : 100;
4023                        cp++;   /* % is always at the end */
4024                        break;
4025                } else if ( ch >= '0' && ch <= '9' ) {
4026                        if ( scale < 100000 ) {
4027                                scale *= 10;
4028                                num = (num*10) + (ch-'0');
4029                        }
4030                } else {
4031                        break;
4032                }
4033                cp++;
4034        }
4035        *cp_p = cp;
4036
4037        /* user says num divided by scale and we say internally that
4038         * is MAX_SCORE * num / scale.
4039         */
4040        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
4041}
4042
4043static int diff_scoreopt_parse(const char *opt)
4044{
4045        int opt1, opt2, cmd;
4046
4047        if (*opt++ != '-')
4048                return -1;
4049        cmd = *opt++;
4050        if (cmd == '-') {
4051                /* convert the long-form arguments into short-form versions */
4052                if (skip_prefix(opt, "break-rewrites", &opt)) {
4053                        if (*opt == 0 || *opt++ == '=')
4054                                cmd = 'B';
4055                } else if (skip_prefix(opt, "find-copies", &opt)) {
4056                        if (*opt == 0 || *opt++ == '=')
4057                                cmd = 'C';
4058                } else if (skip_prefix(opt, "find-renames", &opt)) {
4059                        if (*opt == 0 || *opt++ == '=')
4060                                cmd = 'M';
4061                }
4062        }
4063        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
4064                return -1; /* that is not a -M, -C, or -B option */
4065
4066        opt1 = parse_rename_score(&opt);
4067        if (cmd != 'B')
4068                opt2 = 0;
4069        else {
4070                if (*opt == 0)
4071                        opt2 = 0;
4072                else if (*opt != '/')
4073                        return -1; /* we expect -B80/99 or -B80 */
4074                else {
4075                        opt++;
4076                        opt2 = parse_rename_score(&opt);
4077                }
4078        }
4079        if (*opt != 0)
4080                return -1;
4081        return opt1 | (opt2 << 16);
4082}
4083
4084struct diff_queue_struct diff_queued_diff;
4085
4086void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
4087{
4088        ALLOC_GROW(queue->queue, queue->nr + 1, queue->alloc);
4089        queue->queue[queue->nr++] = dp;
4090}
4091
4092struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
4093                                 struct diff_filespec *one,
4094                                 struct diff_filespec *two)
4095{
4096        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
4097        dp->one = one;
4098        dp->two = two;
4099        if (queue)
4100                diff_q(queue, dp);
4101        return dp;
4102}
4103
4104void diff_free_filepair(struct diff_filepair *p)
4105{
4106        free_filespec(p->one);
4107        free_filespec(p->two);
4108        free(p);
4109}
4110
4111/* This is different from find_unique_abbrev() in that
4112 * it stuffs the result with dots for alignment.
4113 */
4114const char *diff_unique_abbrev(const unsigned char *sha1, int len)
4115{
4116        int abblen;
4117        const char *abbrev;
4118        if (len == 40)
4119                return sha1_to_hex(sha1);
4120
4121        abbrev = find_unique_abbrev(sha1, len);
4122        abblen = strlen(abbrev);
4123        if (abblen < 37) {
4124                static char hex[41];
4125                if (len < abblen && abblen <= len + 2)
4126                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
4127                else
4128                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
4129                return hex;
4130        }
4131        return sha1_to_hex(sha1);
4132}
4133
4134static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
4135{
4136        int line_termination = opt->line_termination;
4137        int inter_name_termination = line_termination ? '\t' : '\0';
4138
4139        fprintf(opt->file, "%s", diff_line_prefix(opt));
4140        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
4141                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
4142                        diff_unique_abbrev(p->one->oid.hash, opt->abbrev));
4143                fprintf(opt->file, "%s ",
4144                        diff_unique_abbrev(p->two->oid.hash, opt->abbrev));
4145        }
4146        if (p->score) {
4147                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
4148                        inter_name_termination);
4149        } else {
4150                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
4151        }
4152
4153        if (p->status == DIFF_STATUS_COPIED ||
4154            p->status == DIFF_STATUS_RENAMED) {
4155                const char *name_a, *name_b;
4156                name_a = p->one->path;
4157                name_b = p->two->path;
4158                strip_prefix(opt->prefix_length, &name_a, &name_b);
4159                write_name_quoted(name_a, opt->file, inter_name_termination);
4160                write_name_quoted(name_b, opt->file, line_termination);
4161        } else {
4162                const char *name_a, *name_b;
4163                name_a = p->one->mode ? p->one->path : p->two->path;
4164                name_b = NULL;
4165                strip_prefix(opt->prefix_length, &name_a, &name_b);
4166                write_name_quoted(name_a, opt->file, line_termination);
4167        }
4168}
4169
4170int diff_unmodified_pair(struct diff_filepair *p)
4171{
4172        /* This function is written stricter than necessary to support
4173         * the currently implemented transformers, but the idea is to
4174         * let transformers to produce diff_filepairs any way they want,
4175         * and filter and clean them up here before producing the output.
4176         */
4177        struct diff_filespec *one = p->one, *two = p->two;
4178
4179        if (DIFF_PAIR_UNMERGED(p))
4180                return 0; /* unmerged is interesting */
4181
4182        /* deletion, addition, mode or type change
4183         * and rename are all interesting.
4184         */
4185        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
4186            DIFF_PAIR_MODE_CHANGED(p) ||
4187            strcmp(one->path, two->path))
4188                return 0;
4189
4190        /* both are valid and point at the same path.  that is, we are
4191         * dealing with a change.
4192         */
4193        if (one->oid_valid && two->oid_valid &&
4194            !oidcmp(&one->oid, &two->oid) &&
4195            !one->dirty_submodule && !two->dirty_submodule)
4196                return 1; /* no change */
4197        if (!one->oid_valid && !two->oid_valid)
4198                return 1; /* both look at the same file on the filesystem. */
4199        return 0;
4200}
4201
4202static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
4203{
4204        if (diff_unmodified_pair(p))
4205                return;
4206
4207        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4208            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4209                return; /* no tree diffs in patch format */
4210
4211        run_diff(p, o);
4212}
4213
4214static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
4215                            struct diffstat_t *diffstat)
4216{
4217        if (diff_unmodified_pair(p))
4218                return;
4219
4220        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4221            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4222                return; /* no useful stat for tree diffs */
4223
4224        run_diffstat(p, o, diffstat);
4225}
4226
4227static void diff_flush_checkdiff(struct diff_filepair *p,
4228                struct diff_options *o)
4229{
4230        if (diff_unmodified_pair(p))
4231                return;
4232
4233        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4234            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4235                return; /* nothing to check in tree diffs */
4236
4237        run_checkdiff(p, o);
4238}
4239
4240int diff_queue_is_empty(void)
4241{
4242        struct diff_queue_struct *q = &diff_queued_diff;
4243        int i;
4244        for (i = 0; i < q->nr; i++)
4245                if (!diff_unmodified_pair(q->queue[i]))
4246                        return 0;
4247        return 1;
4248}
4249
4250#if DIFF_DEBUG
4251void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
4252{
4253        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
4254                x, one ? one : "",
4255                s->path,
4256                DIFF_FILE_VALID(s) ? "valid" : "invalid",
4257                s->mode,
4258                s->oid_valid ? oid_to_hex(&s->oid) : "");
4259        fprintf(stderr, "queue[%d] %s size %lu\n",
4260                x, one ? one : "",
4261                s->size);
4262}
4263
4264void diff_debug_filepair(const struct diff_filepair *p, int i)
4265{
4266        diff_debug_filespec(p->one, i, "one");
4267        diff_debug_filespec(p->two, i, "two");
4268        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
4269                p->score, p->status ? p->status : '?',
4270                p->one->rename_used, p->broken_pair);
4271}
4272
4273void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
4274{
4275        int i;
4276        if (msg)
4277                fprintf(stderr, "%s\n", msg);
4278        fprintf(stderr, "q->nr = %d\n", q->nr);
4279        for (i = 0; i < q->nr; i++) {
4280                struct diff_filepair *p = q->queue[i];
4281                diff_debug_filepair(p, i);
4282        }
4283}
4284#endif
4285
4286static void diff_resolve_rename_copy(void)
4287{
4288        int i;
4289        struct diff_filepair *p;
4290        struct diff_queue_struct *q = &diff_queued_diff;
4291
4292        diff_debug_queue("resolve-rename-copy", q);
4293
4294        for (i = 0; i < q->nr; i++) {
4295                p = q->queue[i];
4296                p->status = 0; /* undecided */
4297                if (DIFF_PAIR_UNMERGED(p))
4298                        p->status = DIFF_STATUS_UNMERGED;
4299                else if (!DIFF_FILE_VALID(p->one))
4300                        p->status = DIFF_STATUS_ADDED;
4301                else if (!DIFF_FILE_VALID(p->two))
4302                        p->status = DIFF_STATUS_DELETED;
4303                else if (DIFF_PAIR_TYPE_CHANGED(p))
4304                        p->status = DIFF_STATUS_TYPE_CHANGED;
4305
4306                /* from this point on, we are dealing with a pair
4307                 * whose both sides are valid and of the same type, i.e.
4308                 * either in-place edit or rename/copy edit.
4309                 */
4310                else if (DIFF_PAIR_RENAME(p)) {
4311                        /*
4312                         * A rename might have re-connected a broken
4313                         * pair up, causing the pathnames to be the
4314                         * same again. If so, that's not a rename at
4315                         * all, just a modification..
4316                         *
4317                         * Otherwise, see if this source was used for
4318                         * multiple renames, in which case we decrement
4319                         * the count, and call it a copy.
4320                         */
4321                        if (!strcmp(p->one->path, p->two->path))
4322                                p->status = DIFF_STATUS_MODIFIED;
4323                        else if (--p->one->rename_used > 0)
4324                                p->status = DIFF_STATUS_COPIED;
4325                        else
4326                                p->status = DIFF_STATUS_RENAMED;
4327                }
4328                else if (oidcmp(&p->one->oid, &p->two->oid) ||
4329                         p->one->mode != p->two->mode ||
4330                         p->one->dirty_submodule ||
4331                         p->two->dirty_submodule ||
4332                         is_null_oid(&p->one->oid))
4333                        p->status = DIFF_STATUS_MODIFIED;
4334                else {
4335                        /* This is a "no-change" entry and should not
4336                         * happen anymore, but prepare for broken callers.
4337                         */
4338                        error("feeding unmodified %s to diffcore",
4339                              p->one->path);
4340                        p->status = DIFF_STATUS_UNKNOWN;
4341                }
4342        }
4343        diff_debug_queue("resolve-rename-copy done", q);
4344}
4345
4346static int check_pair_status(struct diff_filepair *p)
4347{
4348        switch (p->status) {
4349        case DIFF_STATUS_UNKNOWN:
4350                return 0;
4351        case 0:
4352                die("internal error in diff-resolve-rename-copy");
4353        default:
4354                return 1;
4355        }
4356}
4357
4358static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
4359{
4360        int fmt = opt->output_format;
4361
4362        if (fmt & DIFF_FORMAT_CHECKDIFF)
4363                diff_flush_checkdiff(p, opt);
4364        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
4365                diff_flush_raw(p, opt);
4366        else if (fmt & DIFF_FORMAT_NAME) {
4367                const char *name_a, *name_b;
4368                name_a = p->two->path;
4369                name_b = NULL;
4370                strip_prefix(opt->prefix_length, &name_a, &name_b);
4371                write_name_quoted(name_a, opt->file, opt->line_termination);
4372        }
4373}
4374
4375static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
4376{
4377        if (fs->mode)
4378                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
4379        else
4380                fprintf(file, " %s ", newdelete);
4381        write_name_quoted(fs->path, file, '\n');
4382}
4383
4384
4385static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
4386                const char *line_prefix)
4387{
4388        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
4389                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
4390                        p->two->mode, show_name ? ' ' : '\n');
4391                if (show_name) {
4392                        write_name_quoted(p->two->path, file, '\n');
4393                }
4394        }
4395}
4396
4397static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
4398                        const char *line_prefix)
4399{
4400        char *names = pprint_rename(p->one->path, p->two->path);
4401
4402        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
4403        free(names);
4404        show_mode_change(file, p, 0, line_prefix);
4405}
4406
4407static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
4408{
4409        FILE *file = opt->file;
4410        const char *line_prefix = diff_line_prefix(opt);
4411
4412        switch(p->status) {
4413        case DIFF_STATUS_DELETED:
4414                fputs(line_prefix, file);
4415                show_file_mode_name(file, "delete", p->one);
4416                break;
4417        case DIFF_STATUS_ADDED:
4418                fputs(line_prefix, file);
4419                show_file_mode_name(file, "create", p->two);
4420                break;
4421        case DIFF_STATUS_COPIED:
4422                fputs(line_prefix, file);
4423                show_rename_copy(file, "copy", p, line_prefix);
4424                break;
4425        case DIFF_STATUS_RENAMED:
4426                fputs(line_prefix, file);
4427                show_rename_copy(file, "rename", p, line_prefix);
4428                break;
4429        default:
4430                if (p->score) {
4431                        fprintf(file, "%s rewrite ", line_prefix);
4432                        write_name_quoted(p->two->path, file, ' ');
4433                        fprintf(file, "(%d%%)\n", similarity_index(p));
4434                }
4435                show_mode_change(file, p, !p->score, line_prefix);
4436                break;
4437        }
4438}
4439
4440struct patch_id_t {
4441        git_SHA_CTX *ctx;
4442        int patchlen;
4443};
4444
4445static int remove_space(char *line, int len)
4446{
4447        int i;
4448        char *dst = line;
4449        unsigned char c;
4450
4451        for (i = 0; i < len; i++)
4452                if (!isspace((c = line[i])))
4453                        *dst++ = c;
4454
4455        return dst - line;
4456}
4457
4458static void patch_id_consume(void *priv, char *line, unsigned long len)
4459{
4460        struct patch_id_t *data = priv;
4461        int new_len;
4462
4463        /* Ignore line numbers when computing the SHA1 of the patch */
4464        if (starts_with(line, "@@ -"))
4465                return;
4466
4467        new_len = remove_space(line, len);
4468
4469        git_SHA1_Update(data->ctx, line, new_len);
4470        data->patchlen += new_len;
4471}
4472
4473/* returns 0 upon success, and writes result into sha1 */
4474static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
4475{
4476        struct diff_queue_struct *q = &diff_queued_diff;
4477        int i;
4478        git_SHA_CTX ctx;
4479        struct patch_id_t data;
4480        char buffer[PATH_MAX * 4 + 20];
4481
4482        git_SHA1_Init(&ctx);
4483        memset(&data, 0, sizeof(struct patch_id_t));
4484        data.ctx = &ctx;
4485
4486        for (i = 0; i < q->nr; i++) {
4487                xpparam_t xpp;
4488                xdemitconf_t xecfg;
4489                mmfile_t mf1, mf2;
4490                struct diff_filepair *p = q->queue[i];
4491                int len1, len2;
4492
4493                memset(&xpp, 0, sizeof(xpp));
4494                memset(&xecfg, 0, sizeof(xecfg));
4495                if (p->status == 0)
4496                        return error("internal diff status error");
4497                if (p->status == DIFF_STATUS_UNKNOWN)
4498                        continue;
4499                if (diff_unmodified_pair(p))
4500                        continue;
4501                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
4502                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
4503                        continue;
4504                if (DIFF_PAIR_UNMERGED(p))
4505                        continue;
4506
4507                diff_fill_sha1_info(p->one);
4508                diff_fill_sha1_info(p->two);
4509
4510                len1 = remove_space(p->one->path, strlen(p->one->path));
4511                len2 = remove_space(p->two->path, strlen(p->two->path));
4512                if (p->one->mode == 0)
4513                        len1 = snprintf(buffer, sizeof(buffer),
4514                                        "diff--gita/%.*sb/%.*s"
4515                                        "newfilemode%06o"
4516                                        "---/dev/null"
4517                                        "+++b/%.*s",
4518                                        len1, p->one->path,
4519                                        len2, p->two->path,
4520                                        p->two->mode,
4521                                        len2, p->two->path);
4522                else if (p->two->mode == 0)
4523                        len1 = snprintf(buffer, sizeof(buffer),
4524                                        "diff--gita/%.*sb/%.*s"
4525                                        "deletedfilemode%06o"
4526                                        "---a/%.*s"
4527                                        "+++/dev/null",
4528                                        len1, p->one->path,
4529                                        len2, p->two->path,
4530                                        p->one->mode,
4531                                        len1, p->one->path);
4532                else
4533                        len1 = snprintf(buffer, sizeof(buffer),
4534                                        "diff--gita/%.*sb/%.*s"
4535                                        "---a/%.*s"
4536                                        "+++b/%.*s",
4537                                        len1, p->one->path,
4538                                        len2, p->two->path,
4539                                        len1, p->one->path,
4540                                        len2, p->two->path);
4541                git_SHA1_Update(&ctx, buffer, len1);
4542
4543                if (diff_header_only)
4544                        continue;
4545
4546                if (fill_mmfile(&mf1, p->one) < 0 ||
4547                    fill_mmfile(&mf2, p->two) < 0)
4548                        return error("unable to read files to diff");
4549
4550                if (diff_filespec_is_binary(p->one) ||
4551                    diff_filespec_is_binary(p->two)) {
4552                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
4553                                        40);
4554                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
4555                                        40);
4556                        continue;
4557                }
4558
4559                xpp.flags = 0;
4560                xecfg.ctxlen = 3;
4561                xecfg.flags = 0;
4562                if (xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
4563                                  &xpp, &xecfg))
4564                        return error("unable to generate patch-id diff for %s",
4565                                     p->one->path);
4566        }
4567
4568        git_SHA1_Final(sha1, &ctx);
4569        return 0;
4570}
4571
4572int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
4573{
4574        struct diff_queue_struct *q = &diff_queued_diff;
4575        int i;
4576        int result = diff_get_patch_id(options, sha1, diff_header_only);
4577
4578        for (i = 0; i < q->nr; i++)
4579                diff_free_filepair(q->queue[i]);
4580
4581        free(q->queue);
4582        DIFF_QUEUE_CLEAR(q);
4583
4584        return result;
4585}
4586
4587static int is_summary_empty(const struct diff_queue_struct *q)
4588{
4589        int i;
4590
4591        for (i = 0; i < q->nr; i++) {
4592                const struct diff_filepair *p = q->queue[i];
4593
4594                switch (p->status) {
4595                case DIFF_STATUS_DELETED:
4596                case DIFF_STATUS_ADDED:
4597                case DIFF_STATUS_COPIED:
4598                case DIFF_STATUS_RENAMED:
4599                        return 0;
4600                default:
4601                        if (p->score)
4602                                return 0;
4603                        if (p->one->mode && p->two->mode &&
4604                            p->one->mode != p->two->mode)
4605                                return 0;
4606                        break;
4607                }
4608        }
4609        return 1;
4610}
4611
4612static const char rename_limit_warning[] =
4613"inexact rename detection was skipped due to too many files.";
4614
4615static const char degrade_cc_to_c_warning[] =
4616"only found copies from modified paths due to too many files.";
4617
4618static const char rename_limit_advice[] =
4619"you may want to set your %s variable to at least "
4620"%d and retry the command.";
4621
4622void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
4623{
4624        if (degraded_cc)
4625                warning(degrade_cc_to_c_warning);
4626        else if (needed)
4627                warning(rename_limit_warning);
4628        else
4629                return;
4630        if (0 < needed && needed < 32767)
4631                warning(rename_limit_advice, varname, needed);
4632}
4633
4634void diff_flush(struct diff_options *options)
4635{
4636        struct diff_queue_struct *q = &diff_queued_diff;
4637        int i, output_format = options->output_format;
4638        int separator = 0;
4639        int dirstat_by_line = 0;
4640
4641        /*
4642         * Order: raw, stat, summary, patch
4643         * or:    name/name-status/checkdiff (other bits clear)
4644         */
4645        if (!q->nr)
4646                goto free_queue;
4647
4648        if (output_format & (DIFF_FORMAT_RAW |
4649                             DIFF_FORMAT_NAME |
4650                             DIFF_FORMAT_NAME_STATUS |
4651                             DIFF_FORMAT_CHECKDIFF)) {
4652                for (i = 0; i < q->nr; i++) {
4653                        struct diff_filepair *p = q->queue[i];
4654                        if (check_pair_status(p))
4655                                flush_one_pair(p, options);
4656                }
4657                separator++;
4658        }
4659
4660        if (output_format & DIFF_FORMAT_DIRSTAT && DIFF_OPT_TST(options, DIRSTAT_BY_LINE))
4661                dirstat_by_line = 1;
4662
4663        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT) ||
4664            dirstat_by_line) {
4665                struct diffstat_t diffstat;
4666
4667                memset(&diffstat, 0, sizeof(struct diffstat_t));
4668                for (i = 0; i < q->nr; i++) {
4669                        struct diff_filepair *p = q->queue[i];
4670                        if (check_pair_status(p))
4671                                diff_flush_stat(p, options, &diffstat);
4672                }
4673                if (output_format & DIFF_FORMAT_NUMSTAT)
4674                        show_numstat(&diffstat, options);
4675                if (output_format & DIFF_FORMAT_DIFFSTAT)
4676                        show_stats(&diffstat, options);
4677                if (output_format & DIFF_FORMAT_SHORTSTAT)
4678                        show_shortstats(&diffstat, options);
4679                if (output_format & DIFF_FORMAT_DIRSTAT && dirstat_by_line)
4680                        show_dirstat_by_line(&diffstat, options);
4681                free_diffstat_info(&diffstat);
4682                separator++;
4683        }
4684        if ((output_format & DIFF_FORMAT_DIRSTAT) && !dirstat_by_line)
4685                show_dirstat(options);
4686
4687        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
4688                for (i = 0; i < q->nr; i++) {
4689                        diff_summary(options, q->queue[i]);
4690                }
4691                separator++;
4692        }
4693
4694        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
4695            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
4696            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4697                /*
4698                 * run diff_flush_patch for the exit status. setting
4699                 * options->file to /dev/null should be safe, because we
4700                 * aren't supposed to produce any output anyway.
4701                 */
4702                if (options->close_file)
4703                        fclose(options->file);
4704                options->file = fopen("/dev/null", "w");
4705                if (!options->file)
4706                        die_errno("Could not open /dev/null");
4707                options->close_file = 1;
4708                for (i = 0; i < q->nr; i++) {
4709                        struct diff_filepair *p = q->queue[i];
4710                        if (check_pair_status(p))
4711                                diff_flush_patch(p, options);
4712                        if (options->found_changes)
4713                                break;
4714                }
4715        }
4716
4717        if (output_format & DIFF_FORMAT_PATCH) {
4718                if (separator) {
4719                        fprintf(options->file, "%s%c",
4720                                diff_line_prefix(options),
4721                                options->line_termination);
4722                        if (options->stat_sep) {
4723                                /* attach patch instead of inline */
4724                                fputs(options->stat_sep, options->file);
4725                        }
4726                }
4727
4728                for (i = 0; i < q->nr; i++) {
4729                        struct diff_filepair *p = q->queue[i];
4730                        if (check_pair_status(p))
4731                                diff_flush_patch(p, options);
4732                }
4733        }
4734
4735        if (output_format & DIFF_FORMAT_CALLBACK)
4736                options->format_callback(q, options, options->format_callback_data);
4737
4738        for (i = 0; i < q->nr; i++)
4739                diff_free_filepair(q->queue[i]);
4740free_queue:
4741        free(q->queue);
4742        DIFF_QUEUE_CLEAR(q);
4743        if (options->close_file)
4744                fclose(options->file);
4745
4746        /*
4747         * Report the content-level differences with HAS_CHANGES;
4748         * diff_addremove/diff_change does not set the bit when
4749         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
4750         */
4751        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
4752                if (options->found_changes)
4753                        DIFF_OPT_SET(options, HAS_CHANGES);
4754                else
4755                        DIFF_OPT_CLR(options, HAS_CHANGES);
4756        }
4757}
4758
4759static int match_filter(const struct diff_options *options, const struct diff_filepair *p)
4760{
4761        return (((p->status == DIFF_STATUS_MODIFIED) &&
4762                 ((p->score &&
4763                   filter_bit_tst(DIFF_STATUS_FILTER_BROKEN, options)) ||
4764                  (!p->score &&
4765                   filter_bit_tst(DIFF_STATUS_MODIFIED, options)))) ||
4766                ((p->status != DIFF_STATUS_MODIFIED) &&
4767                 filter_bit_tst(p->status, options)));
4768}
4769
4770static void diffcore_apply_filter(struct diff_options *options)
4771{
4772        int i;
4773        struct diff_queue_struct *q = &diff_queued_diff;
4774        struct diff_queue_struct outq;
4775
4776        DIFF_QUEUE_CLEAR(&outq);
4777
4778        if (!options->filter)
4779                return;
4780
4781        if (filter_bit_tst(DIFF_STATUS_FILTER_AON, options)) {
4782                int found;
4783                for (i = found = 0; !found && i < q->nr; i++) {
4784                        if (match_filter(options, q->queue[i]))
4785                                found++;
4786                }
4787                if (found)
4788                        return;
4789
4790                /* otherwise we will clear the whole queue
4791                 * by copying the empty outq at the end of this
4792                 * function, but first clear the current entries
4793                 * in the queue.
4794                 */
4795                for (i = 0; i < q->nr; i++)
4796                        diff_free_filepair(q->queue[i]);
4797        }
4798        else {
4799                /* Only the matching ones */
4800                for (i = 0; i < q->nr; i++) {
4801                        struct diff_filepair *p = q->queue[i];
4802                        if (match_filter(options, p))
4803                                diff_q(&outq, p);
4804                        else
4805                                diff_free_filepair(p);
4806                }
4807        }
4808        free(q->queue);
4809        *q = outq;
4810}
4811
4812/* Check whether two filespecs with the same mode and size are identical */
4813static int diff_filespec_is_identical(struct diff_filespec *one,
4814                                      struct diff_filespec *two)
4815{
4816        if (S_ISGITLINK(one->mode))
4817                return 0;
4818        if (diff_populate_filespec(one, 0))
4819                return 0;
4820        if (diff_populate_filespec(two, 0))
4821                return 0;
4822        return !memcmp(one->data, two->data, one->size);
4823}
4824
4825static int diff_filespec_check_stat_unmatch(struct diff_filepair *p)
4826{
4827        if (p->done_skip_stat_unmatch)
4828                return p->skip_stat_unmatch_result;
4829
4830        p->done_skip_stat_unmatch = 1;
4831        p->skip_stat_unmatch_result = 0;
4832        /*
4833         * 1. Entries that come from stat info dirtiness
4834         *    always have both sides (iow, not create/delete),
4835         *    one side of the object name is unknown, with
4836         *    the same mode and size.  Keep the ones that
4837         *    do not match these criteria.  They have real
4838         *    differences.
4839         *
4840         * 2. At this point, the file is known to be modified,
4841         *    with the same mode and size, and the object
4842         *    name of one side is unknown.  Need to inspect
4843         *    the identical contents.
4844         */
4845        if (!DIFF_FILE_VALID(p->one) || /* (1) */
4846            !DIFF_FILE_VALID(p->two) ||
4847            (p->one->oid_valid && p->two->oid_valid) ||
4848            (p->one->mode != p->two->mode) ||
4849            diff_populate_filespec(p->one, CHECK_SIZE_ONLY) ||
4850            diff_populate_filespec(p->two, CHECK_SIZE_ONLY) ||
4851            (p->one->size != p->two->size) ||
4852            !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4853                p->skip_stat_unmatch_result = 1;
4854        return p->skip_stat_unmatch_result;
4855}
4856
4857static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4858{
4859        int i;
4860        struct diff_queue_struct *q = &diff_queued_diff;
4861        struct diff_queue_struct outq;
4862        DIFF_QUEUE_CLEAR(&outq);
4863
4864        for (i = 0; i < q->nr; i++) {
4865                struct diff_filepair *p = q->queue[i];
4866
4867                if (diff_filespec_check_stat_unmatch(p))
4868                        diff_q(&outq, p);
4869                else {
4870                        /*
4871                         * The caller can subtract 1 from skip_stat_unmatch
4872                         * to determine how many paths were dirty only
4873                         * due to stat info mismatch.
4874                         */
4875                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4876                                diffopt->skip_stat_unmatch++;
4877                        diff_free_filepair(p);
4878                }
4879        }
4880        free(q->queue);
4881        *q = outq;
4882}
4883
4884static int diffnamecmp(const void *a_, const void *b_)
4885{
4886        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4887        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4888        const char *name_a, *name_b;
4889
4890        name_a = a->one ? a->one->path : a->two->path;
4891        name_b = b->one ? b->one->path : b->two->path;
4892        return strcmp(name_a, name_b);
4893}
4894
4895void diffcore_fix_diff_index(struct diff_options *options)
4896{
4897        struct diff_queue_struct *q = &diff_queued_diff;
4898        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4899}
4900
4901void diffcore_std(struct diff_options *options)
4902{
4903        /* NOTE please keep the following in sync with diff_tree_combined() */
4904        if (options->skip_stat_unmatch)
4905                diffcore_skip_stat_unmatch(options);
4906        if (!options->found_follow) {
4907                /* See try_to_follow_renames() in tree-diff.c */
4908                if (options->break_opt != -1)
4909                        diffcore_break(options->break_opt);
4910                if (options->detect_rename)
4911                        diffcore_rename(options);
4912                if (options->break_opt != -1)
4913                        diffcore_merge_broken();
4914        }
4915        if (options->pickaxe)
4916                diffcore_pickaxe(options);
4917        if (options->orderfile)
4918                diffcore_order(options->orderfile);
4919        if (!options->found_follow)
4920                /* See try_to_follow_renames() in tree-diff.c */
4921                diff_resolve_rename_copy();
4922        diffcore_apply_filter(options);
4923
4924        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4925                DIFF_OPT_SET(options, HAS_CHANGES);
4926        else
4927                DIFF_OPT_CLR(options, HAS_CHANGES);
4928
4929        options->found_follow = 0;
4930}
4931
4932int diff_result_code(struct diff_options *opt, int status)
4933{
4934        int result = 0;
4935
4936        diff_warn_rename_limit("diff.renameLimit",
4937                               opt->needed_rename_limit,
4938                               opt->degraded_cc_to_c);
4939        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4940            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4941                return status;
4942        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4943            DIFF_OPT_TST(opt, HAS_CHANGES))
4944                result |= 01;
4945        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4946            DIFF_OPT_TST(opt, CHECK_FAILED))
4947                result |= 02;
4948        return result;
4949}
4950
4951int diff_can_quit_early(struct diff_options *opt)
4952{
4953        return (DIFF_OPT_TST(opt, QUICK) &&
4954                !opt->filter &&
4955                DIFF_OPT_TST(opt, HAS_CHANGES));
4956}
4957
4958/*
4959 * Shall changes to this submodule be ignored?
4960 *
4961 * Submodule changes can be configured to be ignored separately for each path,
4962 * but that configuration can be overridden from the command line.
4963 */
4964static int is_submodule_ignored(const char *path, struct diff_options *options)
4965{
4966        int ignored = 0;
4967        unsigned orig_flags = options->flags;
4968        if (!DIFF_OPT_TST(options, OVERRIDE_SUBMODULE_CONFIG))
4969                set_diffopt_flags_from_submodule_config(options, path);
4970        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES))
4971                ignored = 1;
4972        options->flags = orig_flags;
4973        return ignored;
4974}
4975
4976void diff_addremove(struct diff_options *options,
4977                    int addremove, unsigned mode,
4978                    const unsigned char *sha1,
4979                    int sha1_valid,
4980                    const char *concatpath, unsigned dirty_submodule)
4981{
4982        struct diff_filespec *one, *two;
4983
4984        if (S_ISGITLINK(mode) && is_submodule_ignored(concatpath, options))
4985                return;
4986
4987        /* This may look odd, but it is a preparation for
4988         * feeding "there are unchanged files which should
4989         * not produce diffs, but when you are doing copy
4990         * detection you would need them, so here they are"
4991         * entries to the diff-core.  They will be prefixed
4992         * with something like '=' or '*' (I haven't decided
4993         * which but should not make any difference).
4994         * Feeding the same new and old to diff_change()
4995         * also has the same effect.
4996         * Before the final output happens, they are pruned after
4997         * merged into rename/copy pairs as appropriate.
4998         */
4999        if (DIFF_OPT_TST(options, REVERSE_DIFF))
5000                addremove = (addremove == '+' ? '-' :
5001                             addremove == '-' ? '+' : addremove);
5002
5003        if (options->prefix &&
5004            strncmp(concatpath, options->prefix, options->prefix_length))
5005                return;
5006
5007        one = alloc_filespec(concatpath);
5008        two = alloc_filespec(concatpath);
5009
5010        if (addremove != '+')
5011                fill_filespec(one, sha1, sha1_valid, mode);
5012        if (addremove != '-') {
5013                fill_filespec(two, sha1, sha1_valid, mode);
5014                two->dirty_submodule = dirty_submodule;
5015        }
5016
5017        diff_queue(&diff_queued_diff, one, two);
5018        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5019                DIFF_OPT_SET(options, HAS_CHANGES);
5020}
5021
5022void diff_change(struct diff_options *options,
5023                 unsigned old_mode, unsigned new_mode,
5024                 const unsigned char *old_sha1,
5025                 const unsigned char *new_sha1,
5026                 int old_sha1_valid, int new_sha1_valid,
5027                 const char *concatpath,
5028                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
5029{
5030        struct diff_filespec *one, *two;
5031        struct diff_filepair *p;
5032
5033        if (S_ISGITLINK(old_mode) && S_ISGITLINK(new_mode) &&
5034            is_submodule_ignored(concatpath, options))
5035                return;
5036
5037        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
5038                unsigned tmp;
5039                const unsigned char *tmp_c;
5040                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
5041                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
5042                tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
5043                        new_sha1_valid = tmp;
5044                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
5045                        new_dirty_submodule = tmp;
5046        }
5047
5048        if (options->prefix &&
5049            strncmp(concatpath, options->prefix, options->prefix_length))
5050                return;
5051
5052        one = alloc_filespec(concatpath);
5053        two = alloc_filespec(concatpath);
5054        fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
5055        fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
5056        one->dirty_submodule = old_dirty_submodule;
5057        two->dirty_submodule = new_dirty_submodule;
5058        p = diff_queue(&diff_queued_diff, one, two);
5059
5060        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
5061                return;
5062
5063        if (DIFF_OPT_TST(options, QUICK) && options->skip_stat_unmatch &&
5064            !diff_filespec_check_stat_unmatch(p))
5065                return;
5066
5067        DIFF_OPT_SET(options, HAS_CHANGES);
5068}
5069
5070struct diff_filepair *diff_unmerge(struct diff_options *options, const char *path)
5071{
5072        struct diff_filepair *pair;
5073        struct diff_filespec *one, *two;
5074
5075        if (options->prefix &&
5076            strncmp(path, options->prefix, options->prefix_length))
5077                return NULL;
5078
5079        one = alloc_filespec(path);
5080        two = alloc_filespec(path);
5081        pair = diff_queue(&diff_queued_diff, one, two);
5082        pair->is_unmerged = 1;
5083        return pair;
5084}
5085
5086static char *run_textconv(const char *pgm, struct diff_filespec *spec,
5087                size_t *outsize)
5088{
5089        struct diff_tempfile *temp;
5090        const char *argv[3];
5091        const char **arg = argv;
5092        struct child_process child = CHILD_PROCESS_INIT;
5093        struct strbuf buf = STRBUF_INIT;
5094        int err = 0;
5095
5096        temp = prepare_temp_file(spec->path, spec);
5097        *arg++ = pgm;
5098        *arg++ = temp->name;
5099        *arg = NULL;
5100
5101        child.use_shell = 1;
5102        child.argv = argv;
5103        child.out = -1;
5104        if (start_command(&child)) {
5105                remove_tempfile();
5106                return NULL;
5107        }
5108
5109        if (strbuf_read(&buf, child.out, 0) < 0)
5110                err = error("error reading from textconv command '%s'", pgm);
5111        close(child.out);
5112
5113        if (finish_command(&child) || err) {
5114                strbuf_release(&buf);
5115                remove_tempfile();
5116                return NULL;
5117        }
5118        remove_tempfile();
5119
5120        return strbuf_detach(&buf, outsize);
5121}
5122
5123size_t fill_textconv(struct userdiff_driver *driver,
5124                     struct diff_filespec *df,
5125                     char **outbuf)
5126{
5127        size_t size;
5128
5129        if (!driver) {
5130                if (!DIFF_FILE_VALID(df)) {
5131                        *outbuf = "";
5132                        return 0;
5133                }
5134                if (diff_populate_filespec(df, 0))
5135                        die("unable to read files to diff");
5136                *outbuf = df->data;
5137                return df->size;
5138        }
5139
5140        if (!driver->textconv)
5141                die("BUG: fill_textconv called with non-textconv driver");
5142
5143        if (driver->textconv_cache && df->oid_valid) {
5144                *outbuf = notes_cache_get(driver->textconv_cache,
5145                                          df->oid.hash,
5146                                          &size);
5147                if (*outbuf)
5148                        return size;
5149        }
5150
5151        *outbuf = run_textconv(driver->textconv, df, &size);
5152        if (!*outbuf)
5153                die("unable to read files to diff");
5154
5155        if (driver->textconv_cache && df->oid_valid) {
5156                /* ignore errors, as we might be in a readonly repository */
5157                notes_cache_put(driver->textconv_cache, df->oid.hash, *outbuf,
5158                                size);
5159                /*
5160                 * we could save up changes and flush them all at the end,
5161                 * but we would need an extra call after all diffing is done.
5162                 * Since generating a cache entry is the slow path anyway,
5163                 * this extra overhead probably isn't a big deal.
5164                 */
5165                notes_cache_write(driver->textconv_cache);
5166        }
5167
5168        return size;
5169}
5170
5171void setup_diff_pager(struct diff_options *opt)
5172{
5173        /*
5174         * If the user asked for our exit code, then either they want --quiet
5175         * or --exit-code. We should definitely not bother with a pager in the
5176         * former case, as we will generate no output. Since we still properly
5177         * report our exit code even when a pager is run, we _could_ run a
5178         * pager with --exit-code. But since we have not done so historically,
5179         * and because it is easy to find people oneline advising "git diff
5180         * --exit-code" in hooks and other scripts, we do not do so.
5181         */
5182        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
5183            check_pager_config("diff") != 0)
5184                setup_pager();
5185}