diff.con commit blame,cat-file --textconv: Don't assume mode is ``S_IFREF | 0664'' (9006471)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 200;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34
  35static char diff_colors[][COLOR_MAXLEN] = {
  36        GIT_COLOR_RESET,
  37        GIT_COLOR_NORMAL,       /* PLAIN */
  38        GIT_COLOR_BOLD,         /* METAINFO */
  39        GIT_COLOR_CYAN,         /* FRAGINFO */
  40        GIT_COLOR_RED,          /* OLD */
  41        GIT_COLOR_GREEN,        /* NEW */
  42        GIT_COLOR_YELLOW,       /* COMMIT */
  43        GIT_COLOR_BG_RED,       /* WHITESPACE */
  44        GIT_COLOR_NORMAL,       /* FUNCINFO */
  45};
  46
  47static int parse_diff_color_slot(const char *var, int ofs)
  48{
  49        if (!strcasecmp(var+ofs, "plain"))
  50                return DIFF_PLAIN;
  51        if (!strcasecmp(var+ofs, "meta"))
  52                return DIFF_METAINFO;
  53        if (!strcasecmp(var+ofs, "frag"))
  54                return DIFF_FRAGINFO;
  55        if (!strcasecmp(var+ofs, "old"))
  56                return DIFF_FILE_OLD;
  57        if (!strcasecmp(var+ofs, "new"))
  58                return DIFF_FILE_NEW;
  59        if (!strcasecmp(var+ofs, "commit"))
  60                return DIFF_COMMIT;
  61        if (!strcasecmp(var+ofs, "whitespace"))
  62                return DIFF_WHITESPACE;
  63        if (!strcasecmp(var+ofs, "func"))
  64                return DIFF_FUNCINFO;
  65        return -1;
  66}
  67
  68static int git_config_rename(const char *var, const char *value)
  69{
  70        if (!value)
  71                return DIFF_DETECT_RENAME;
  72        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  73                return  DIFF_DETECT_COPY;
  74        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  75}
  76
  77/*
  78 * These are to give UI layer defaults.
  79 * The core-level commands such as git-diff-files should
  80 * never be affected by the setting of diff.renames
  81 * the user happens to have in the configuration file.
  82 */
  83int git_diff_ui_config(const char *var, const char *value, void *cb)
  84{
  85        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  86                diff_use_color_default = git_config_colorbool(var, value, -1);
  87                return 0;
  88        }
  89        if (!strcmp(var, "diff.renames")) {
  90                diff_detect_rename_default = git_config_rename(var, value);
  91                return 0;
  92        }
  93        if (!strcmp(var, "diff.autorefreshindex")) {
  94                diff_auto_refresh_index = git_config_bool(var, value);
  95                return 0;
  96        }
  97        if (!strcmp(var, "diff.mnemonicprefix")) {
  98                diff_mnemonic_prefix = git_config_bool(var, value);
  99                return 0;
 100        }
 101        if (!strcmp(var, "diff.noprefix")) {
 102                diff_no_prefix = git_config_bool(var, value);
 103                return 0;
 104        }
 105        if (!strcmp(var, "diff.external"))
 106                return git_config_string(&external_diff_cmd_cfg, var, value);
 107        if (!strcmp(var, "diff.wordregex"))
 108                return git_config_string(&diff_word_regex_cfg, var, value);
 109
 110        return git_diff_basic_config(var, value, cb);
 111}
 112
 113int git_diff_basic_config(const char *var, const char *value, void *cb)
 114{
 115        if (!strcmp(var, "diff.renamelimit")) {
 116                diff_rename_limit_default = git_config_int(var, value);
 117                return 0;
 118        }
 119
 120        switch (userdiff_config(var, value)) {
 121                case 0: break;
 122                case -1: return -1;
 123                default: return 0;
 124        }
 125
 126        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 127                int slot = parse_diff_color_slot(var, 11);
 128                if (slot < 0)
 129                        return 0;
 130                if (!value)
 131                        return config_error_nonbool(var);
 132                color_parse(value, var, diff_colors[slot]);
 133                return 0;
 134        }
 135
 136        /* like GNU diff's --suppress-blank-empty option  */
 137        if (!strcmp(var, "diff.suppressblankempty") ||
 138                        /* for backwards compatibility */
 139                        !strcmp(var, "diff.suppress-blank-empty")) {
 140                diff_suppress_blank_empty = git_config_bool(var, value);
 141                return 0;
 142        }
 143
 144        return git_color_default_config(var, value, cb);
 145}
 146
 147static char *quote_two(const char *one, const char *two)
 148{
 149        int need_one = quote_c_style(one, NULL, NULL, 1);
 150        int need_two = quote_c_style(two, NULL, NULL, 1);
 151        struct strbuf res = STRBUF_INIT;
 152
 153        if (need_one + need_two) {
 154                strbuf_addch(&res, '"');
 155                quote_c_style(one, &res, NULL, 1);
 156                quote_c_style(two, &res, NULL, 1);
 157                strbuf_addch(&res, '"');
 158        } else {
 159                strbuf_addstr(&res, one);
 160                strbuf_addstr(&res, two);
 161        }
 162        return strbuf_detach(&res, NULL);
 163}
 164
 165static const char *external_diff(void)
 166{
 167        static const char *external_diff_cmd = NULL;
 168        static int done_preparing = 0;
 169
 170        if (done_preparing)
 171                return external_diff_cmd;
 172        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 173        if (!external_diff_cmd)
 174                external_diff_cmd = external_diff_cmd_cfg;
 175        done_preparing = 1;
 176        return external_diff_cmd;
 177}
 178
 179static struct diff_tempfile {
 180        const char *name; /* filename external diff should read from */
 181        char hex[41];
 182        char mode[10];
 183        char tmp_path[PATH_MAX];
 184} diff_temp[2];
 185
 186typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 187
 188struct emit_callback {
 189        int color_diff;
 190        unsigned ws_rule;
 191        int blank_at_eof_in_preimage;
 192        int blank_at_eof_in_postimage;
 193        int lno_in_preimage;
 194        int lno_in_postimage;
 195        sane_truncate_fn truncate;
 196        const char **label_path;
 197        struct diff_words_data *diff_words;
 198        struct diff_options *opt;
 199        int *found_changesp;
 200        struct strbuf *header;
 201};
 202
 203static int count_lines(const char *data, int size)
 204{
 205        int count, ch, completely_empty = 1, nl_just_seen = 0;
 206        count = 0;
 207        while (0 < size--) {
 208                ch = *data++;
 209                if (ch == '\n') {
 210                        count++;
 211                        nl_just_seen = 1;
 212                        completely_empty = 0;
 213                }
 214                else {
 215                        nl_just_seen = 0;
 216                        completely_empty = 0;
 217                }
 218        }
 219        if (completely_empty)
 220                return 0;
 221        if (!nl_just_seen)
 222                count++; /* no trailing newline */
 223        return count;
 224}
 225
 226static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 227{
 228        if (!DIFF_FILE_VALID(one)) {
 229                mf->ptr = (char *)""; /* does not matter */
 230                mf->size = 0;
 231                return 0;
 232        }
 233        else if (diff_populate_filespec(one, 0))
 234                return -1;
 235
 236        mf->ptr = one->data;
 237        mf->size = one->size;
 238        return 0;
 239}
 240
 241static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 242{
 243        char *ptr = mf->ptr;
 244        long size = mf->size;
 245        int cnt = 0;
 246
 247        if (!size)
 248                return cnt;
 249        ptr += size - 1; /* pointing at the very end */
 250        if (*ptr != '\n')
 251                ; /* incomplete line */
 252        else
 253                ptr--; /* skip the last LF */
 254        while (mf->ptr < ptr) {
 255                char *prev_eol;
 256                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 257                        if (*prev_eol == '\n')
 258                                break;
 259                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 260                        break;
 261                cnt++;
 262                ptr = prev_eol - 1;
 263        }
 264        return cnt;
 265}
 266
 267static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 268                               struct emit_callback *ecbdata)
 269{
 270        int l1, l2, at;
 271        unsigned ws_rule = ecbdata->ws_rule;
 272        l1 = count_trailing_blank(mf1, ws_rule);
 273        l2 = count_trailing_blank(mf2, ws_rule);
 274        if (l2 <= l1) {
 275                ecbdata->blank_at_eof_in_preimage = 0;
 276                ecbdata->blank_at_eof_in_postimage = 0;
 277                return;
 278        }
 279        at = count_lines(mf1->ptr, mf1->size);
 280        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 281
 282        at = count_lines(mf2->ptr, mf2->size);
 283        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 284}
 285
 286static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 287                        int first, const char *line, int len)
 288{
 289        int has_trailing_newline, has_trailing_carriage_return;
 290        int nofirst;
 291        FILE *file = o->file;
 292
 293        if (o->output_prefix) {
 294                struct strbuf *msg = NULL;
 295                msg = o->output_prefix(o, o->output_prefix_data);
 296                assert(msg);
 297                fwrite(msg->buf, msg->len, 1, file);
 298        }
 299
 300        if (len == 0) {
 301                has_trailing_newline = (first == '\n');
 302                has_trailing_carriage_return = (!has_trailing_newline &&
 303                                                (first == '\r'));
 304                nofirst = has_trailing_newline || has_trailing_carriage_return;
 305        } else {
 306                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 307                if (has_trailing_newline)
 308                        len--;
 309                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 310                if (has_trailing_carriage_return)
 311                        len--;
 312                nofirst = 0;
 313        }
 314
 315        if (len || !nofirst) {
 316                fputs(set, file);
 317                if (!nofirst)
 318                        fputc(first, file);
 319                fwrite(line, len, 1, file);
 320                fputs(reset, file);
 321        }
 322        if (has_trailing_carriage_return)
 323                fputc('\r', file);
 324        if (has_trailing_newline)
 325                fputc('\n', file);
 326}
 327
 328static void emit_line(struct diff_options *o, const char *set, const char *reset,
 329                      const char *line, int len)
 330{
 331        emit_line_0(o, set, reset, line[0], line+1, len-1);
 332}
 333
 334static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 335{
 336        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 337              ecbdata->blank_at_eof_in_preimage &&
 338              ecbdata->blank_at_eof_in_postimage &&
 339              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 340              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 341                return 0;
 342        return ws_blank_line(line, len, ecbdata->ws_rule);
 343}
 344
 345static void emit_add_line(const char *reset,
 346                          struct emit_callback *ecbdata,
 347                          const char *line, int len)
 348{
 349        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 350        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 351
 352        if (!*ws)
 353                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 354        else if (new_blank_line_at_eof(ecbdata, line, len))
 355                /* Blank line at EOF - paint '+' as well */
 356                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 357        else {
 358                /* Emit just the prefix, then the rest. */
 359                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 360                ws_check_emit(line, len, ecbdata->ws_rule,
 361                              ecbdata->opt->file, set, reset, ws);
 362        }
 363}
 364
 365static void emit_hunk_header(struct emit_callback *ecbdata,
 366                             const char *line, int len)
 367{
 368        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 369        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 370        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 371        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 372        static const char atat[2] = { '@', '@' };
 373        const char *cp, *ep;
 374        struct strbuf msgbuf = STRBUF_INIT;
 375        int org_len = len;
 376        int i = 1;
 377
 378        /*
 379         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 380         * it always is at least 10 bytes long.
 381         */
 382        if (len < 10 ||
 383            memcmp(line, atat, 2) ||
 384            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 385                emit_line(ecbdata->opt, plain, reset, line, len);
 386                return;
 387        }
 388        ep += 2; /* skip over @@ */
 389
 390        /* The hunk header in fraginfo color */
 391        strbuf_add(&msgbuf, frag, strlen(frag));
 392        strbuf_add(&msgbuf, line, ep - line);
 393        strbuf_add(&msgbuf, reset, strlen(reset));
 394
 395        /*
 396         * trailing "\r\n"
 397         */
 398        for ( ; i < 3; i++)
 399                if (line[len - i] == '\r' || line[len - i] == '\n')
 400                        len--;
 401
 402        /* blank before the func header */
 403        for (cp = ep; ep - line < len; ep++)
 404                if (*ep != ' ' && *ep != '\t')
 405                        break;
 406        if (ep != cp) {
 407                strbuf_add(&msgbuf, plain, strlen(plain));
 408                strbuf_add(&msgbuf, cp, ep - cp);
 409                strbuf_add(&msgbuf, reset, strlen(reset));
 410        }
 411
 412        if (ep < line + len) {
 413                strbuf_add(&msgbuf, func, strlen(func));
 414                strbuf_add(&msgbuf, ep, line + len - ep);
 415                strbuf_add(&msgbuf, reset, strlen(reset));
 416        }
 417
 418        strbuf_add(&msgbuf, line + len, org_len - len);
 419        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 420        strbuf_release(&msgbuf);
 421}
 422
 423static struct diff_tempfile *claim_diff_tempfile(void) {
 424        int i;
 425        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 426                if (!diff_temp[i].name)
 427                        return diff_temp + i;
 428        die("BUG: diff is failing to clean up its tempfiles");
 429}
 430
 431static int remove_tempfile_installed;
 432
 433static void remove_tempfile(void)
 434{
 435        int i;
 436        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 437                if (diff_temp[i].name == diff_temp[i].tmp_path)
 438                        unlink_or_warn(diff_temp[i].name);
 439                diff_temp[i].name = NULL;
 440        }
 441}
 442
 443static void remove_tempfile_on_signal(int signo)
 444{
 445        remove_tempfile();
 446        sigchain_pop(signo);
 447        raise(signo);
 448}
 449
 450static void print_line_count(FILE *file, int count)
 451{
 452        switch (count) {
 453        case 0:
 454                fprintf(file, "0,0");
 455                break;
 456        case 1:
 457                fprintf(file, "1");
 458                break;
 459        default:
 460                fprintf(file, "1,%d", count);
 461                break;
 462        }
 463}
 464
 465static void emit_rewrite_lines(struct emit_callback *ecb,
 466                               int prefix, const char *data, int size)
 467{
 468        const char *endp = NULL;
 469        static const char *nneof = " No newline at end of file\n";
 470        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 471        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 472
 473        while (0 < size) {
 474                int len;
 475
 476                endp = memchr(data, '\n', size);
 477                len = endp ? (endp - data + 1) : size;
 478                if (prefix != '+') {
 479                        ecb->lno_in_preimage++;
 480                        emit_line_0(ecb->opt, old, reset, '-',
 481                                    data, len);
 482                } else {
 483                        ecb->lno_in_postimage++;
 484                        emit_add_line(reset, ecb, data, len);
 485                }
 486                size -= len;
 487                data += len;
 488        }
 489        if (!endp) {
 490                const char *plain = diff_get_color(ecb->color_diff,
 491                                                   DIFF_PLAIN);
 492                emit_line_0(ecb->opt, plain, reset, '\\',
 493                            nneof, strlen(nneof));
 494        }
 495}
 496
 497static void emit_rewrite_diff(const char *name_a,
 498                              const char *name_b,
 499                              struct diff_filespec *one,
 500                              struct diff_filespec *two,
 501                              struct userdiff_driver *textconv_one,
 502                              struct userdiff_driver *textconv_two,
 503                              struct diff_options *o)
 504{
 505        int lc_a, lc_b;
 506        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 507        const char *name_a_tab, *name_b_tab;
 508        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 509        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 510        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 511        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 512        const char *a_prefix, *b_prefix;
 513        char *data_one, *data_two;
 514        size_t size_one, size_two;
 515        struct emit_callback ecbdata;
 516        char *line_prefix = "";
 517        struct strbuf *msgbuf;
 518
 519        if (o && o->output_prefix) {
 520                msgbuf = o->output_prefix(o, o->output_prefix_data);
 521                line_prefix = msgbuf->buf;
 522        }
 523
 524        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 525                a_prefix = o->b_prefix;
 526                b_prefix = o->a_prefix;
 527        } else {
 528                a_prefix = o->a_prefix;
 529                b_prefix = o->b_prefix;
 530        }
 531
 532        name_a += (*name_a == '/');
 533        name_b += (*name_b == '/');
 534        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 535        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 536
 537        strbuf_reset(&a_name);
 538        strbuf_reset(&b_name);
 539        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 540        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 541
 542        size_one = fill_textconv(textconv_one, one, &data_one);
 543        size_two = fill_textconv(textconv_two, two, &data_two);
 544
 545        memset(&ecbdata, 0, sizeof(ecbdata));
 546        ecbdata.color_diff = color_diff;
 547        ecbdata.found_changesp = &o->found_changes;
 548        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 549        ecbdata.opt = o;
 550        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 551                mmfile_t mf1, mf2;
 552                mf1.ptr = (char *)data_one;
 553                mf2.ptr = (char *)data_two;
 554                mf1.size = size_one;
 555                mf2.size = size_two;
 556                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 557        }
 558        ecbdata.lno_in_preimage = 1;
 559        ecbdata.lno_in_postimage = 1;
 560
 561        lc_a = count_lines(data_one, size_one);
 562        lc_b = count_lines(data_two, size_two);
 563        fprintf(o->file,
 564                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 565                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 566                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 567                line_prefix, fraginfo);
 568        print_line_count(o->file, lc_a);
 569        fprintf(o->file, " +");
 570        print_line_count(o->file, lc_b);
 571        fprintf(o->file, " @@%s\n", reset);
 572        if (lc_a)
 573                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 574        if (lc_b)
 575                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 576        if (textconv_one)
 577                free((char *)data_one);
 578        if (textconv_two)
 579                free((char *)data_two);
 580}
 581
 582struct diff_words_buffer {
 583        mmfile_t text;
 584        long alloc;
 585        struct diff_words_orig {
 586                const char *begin, *end;
 587        } *orig;
 588        int orig_nr, orig_alloc;
 589};
 590
 591static void diff_words_append(char *line, unsigned long len,
 592                struct diff_words_buffer *buffer)
 593{
 594        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 595        line++;
 596        len--;
 597        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 598        buffer->text.size += len;
 599        buffer->text.ptr[buffer->text.size] = '\0';
 600}
 601
 602struct diff_words_style_elem
 603{
 604        const char *prefix;
 605        const char *suffix;
 606        const char *color; /* NULL; filled in by the setup code if
 607                            * color is enabled */
 608};
 609
 610struct diff_words_style
 611{
 612        enum diff_words_type type;
 613        struct diff_words_style_elem new, old, ctx;
 614        const char *newline;
 615};
 616
 617struct diff_words_style diff_words_styles[] = {
 618        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 619        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 620        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 621};
 622
 623struct diff_words_data {
 624        struct diff_words_buffer minus, plus;
 625        const char *current_plus;
 626        int last_minus;
 627        struct diff_options *opt;
 628        regex_t *word_regex;
 629        enum diff_words_type type;
 630        struct diff_words_style *style;
 631};
 632
 633static int fn_out_diff_words_write_helper(FILE *fp,
 634                                          struct diff_words_style_elem *st_el,
 635                                          const char *newline,
 636                                          size_t count, const char *buf,
 637                                          const char *line_prefix)
 638{
 639        int print = 0;
 640
 641        while (count) {
 642                char *p = memchr(buf, '\n', count);
 643                if (print)
 644                        fputs(line_prefix, fp);
 645                if (p != buf) {
 646                        if (st_el->color && fputs(st_el->color, fp) < 0)
 647                                return -1;
 648                        if (fputs(st_el->prefix, fp) < 0 ||
 649                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 650                            fputs(st_el->suffix, fp) < 0)
 651                                return -1;
 652                        if (st_el->color && *st_el->color
 653                            && fputs(GIT_COLOR_RESET, fp) < 0)
 654                                return -1;
 655                }
 656                if (!p)
 657                        return 0;
 658                if (fputs(newline, fp) < 0)
 659                        return -1;
 660                count -= p + 1 - buf;
 661                buf = p + 1;
 662                print = 1;
 663        }
 664        return 0;
 665}
 666
 667/*
 668 * '--color-words' algorithm can be described as:
 669 *
 670 *   1. collect a the minus/plus lines of a diff hunk, divided into
 671 *      minus-lines and plus-lines;
 672 *
 673 *   2. break both minus-lines and plus-lines into words and
 674 *      place them into two mmfile_t with one word for each line;
 675 *
 676 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 677 *
 678 * And for the common parts of the both file, we output the plus side text.
 679 * diff_words->current_plus is used to trace the current position of the plus file
 680 * which printed. diff_words->last_minus is used to trace the last minus word
 681 * printed.
 682 *
 683 * For '--graph' to work with '--color-words', we need to output the graph prefix
 684 * on each line of color words output. Generally, there are two conditions on
 685 * which we should output the prefix.
 686 *
 687 *   1. diff_words->last_minus == 0 &&
 688 *      diff_words->current_plus == diff_words->plus.text.ptr
 689 *
 690 *      that is: the plus text must start as a new line, and if there is no minus
 691 *      word printed, a graph prefix must be printed.
 692 *
 693 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 694 *      *(diff_words->current_plus - 1) == '\n'
 695 *
 696 *      that is: a graph prefix must be printed following a '\n'
 697 */
 698static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 699{
 700        if ((diff_words->last_minus == 0 &&
 701                diff_words->current_plus == diff_words->plus.text.ptr) ||
 702                (diff_words->current_plus > diff_words->plus.text.ptr &&
 703                *(diff_words->current_plus - 1) == '\n')) {
 704                return 1;
 705        } else {
 706                return 0;
 707        }
 708}
 709
 710static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 711{
 712        struct diff_words_data *diff_words = priv;
 713        struct diff_words_style *style = diff_words->style;
 714        int minus_first, minus_len, plus_first, plus_len;
 715        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 716        struct diff_options *opt = diff_words->opt;
 717        struct strbuf *msgbuf;
 718        char *line_prefix = "";
 719
 720        if (line[0] != '@' || parse_hunk_header(line, len,
 721                        &minus_first, &minus_len, &plus_first, &plus_len))
 722                return;
 723
 724        assert(opt);
 725        if (opt->output_prefix) {
 726                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 727                line_prefix = msgbuf->buf;
 728        }
 729
 730        /* POSIX requires that first be decremented by one if len == 0... */
 731        if (minus_len) {
 732                minus_begin = diff_words->minus.orig[minus_first].begin;
 733                minus_end =
 734                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 735        } else
 736                minus_begin = minus_end =
 737                        diff_words->minus.orig[minus_first].end;
 738
 739        if (plus_len) {
 740                plus_begin = diff_words->plus.orig[plus_first].begin;
 741                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 742        } else
 743                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 744
 745        if (color_words_output_graph_prefix(diff_words)) {
 746                fputs(line_prefix, diff_words->opt->file);
 747        }
 748        if (diff_words->current_plus != plus_begin) {
 749                fn_out_diff_words_write_helper(diff_words->opt->file,
 750                                &style->ctx, style->newline,
 751                                plus_begin - diff_words->current_plus,
 752                                diff_words->current_plus, line_prefix);
 753                if (*(plus_begin - 1) == '\n')
 754                        fputs(line_prefix, diff_words->opt->file);
 755        }
 756        if (minus_begin != minus_end) {
 757                fn_out_diff_words_write_helper(diff_words->opt->file,
 758                                &style->old, style->newline,
 759                                minus_end - minus_begin, minus_begin,
 760                                line_prefix);
 761        }
 762        if (plus_begin != plus_end) {
 763                fn_out_diff_words_write_helper(diff_words->opt->file,
 764                                &style->new, style->newline,
 765                                plus_end - plus_begin, plus_begin,
 766                                line_prefix);
 767        }
 768
 769        diff_words->current_plus = plus_end;
 770        diff_words->last_minus = minus_first;
 771}
 772
 773/* This function starts looking at *begin, and returns 0 iff a word was found. */
 774static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 775                int *begin, int *end)
 776{
 777        if (word_regex && *begin < buffer->size) {
 778                regmatch_t match[1];
 779                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 780                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 781                                        '\n', match[0].rm_eo - match[0].rm_so);
 782                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 783                        *begin += match[0].rm_so;
 784                        return *begin >= *end;
 785                }
 786                return -1;
 787        }
 788
 789        /* find the next word */
 790        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 791                (*begin)++;
 792        if (*begin >= buffer->size)
 793                return -1;
 794
 795        /* find the end of the word */
 796        *end = *begin + 1;
 797        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 798                (*end)++;
 799
 800        return 0;
 801}
 802
 803/*
 804 * This function splits the words in buffer->text, stores the list with
 805 * newline separator into out, and saves the offsets of the original words
 806 * in buffer->orig.
 807 */
 808static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 809                regex_t *word_regex)
 810{
 811        int i, j;
 812        long alloc = 0;
 813
 814        out->size = 0;
 815        out->ptr = NULL;
 816
 817        /* fake an empty "0th" word */
 818        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 819        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 820        buffer->orig_nr = 1;
 821
 822        for (i = 0; i < buffer->text.size; i++) {
 823                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 824                        return;
 825
 826                /* store original boundaries */
 827                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 828                                buffer->orig_alloc);
 829                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 830                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 831                buffer->orig_nr++;
 832
 833                /* store one word */
 834                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 835                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 836                out->ptr[out->size + j - i] = '\n';
 837                out->size += j - i + 1;
 838
 839                i = j - 1;
 840        }
 841}
 842
 843/* this executes the word diff on the accumulated buffers */
 844static void diff_words_show(struct diff_words_data *diff_words)
 845{
 846        xpparam_t xpp;
 847        xdemitconf_t xecfg;
 848        mmfile_t minus, plus;
 849        struct diff_words_style *style = diff_words->style;
 850
 851        struct diff_options *opt = diff_words->opt;
 852        struct strbuf *msgbuf;
 853        char *line_prefix = "";
 854
 855        assert(opt);
 856        if (opt->output_prefix) {
 857                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 858                line_prefix = msgbuf->buf;
 859        }
 860
 861        /* special case: only removal */
 862        if (!diff_words->plus.text.size) {
 863                fputs(line_prefix, diff_words->opt->file);
 864                fn_out_diff_words_write_helper(diff_words->opt->file,
 865                        &style->old, style->newline,
 866                        diff_words->minus.text.size,
 867                        diff_words->minus.text.ptr, line_prefix);
 868                diff_words->minus.text.size = 0;
 869                return;
 870        }
 871
 872        diff_words->current_plus = diff_words->plus.text.ptr;
 873        diff_words->last_minus = 0;
 874
 875        memset(&xpp, 0, sizeof(xpp));
 876        memset(&xecfg, 0, sizeof(xecfg));
 877        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 878        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 879        xpp.flags = 0;
 880        /* as only the hunk header will be parsed, we need a 0-context */
 881        xecfg.ctxlen = 0;
 882        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 883                      &xpp, &xecfg);
 884        free(minus.ptr);
 885        free(plus.ptr);
 886        if (diff_words->current_plus != diff_words->plus.text.ptr +
 887                        diff_words->plus.text.size) {
 888                if (color_words_output_graph_prefix(diff_words))
 889                        fputs(line_prefix, diff_words->opt->file);
 890                fn_out_diff_words_write_helper(diff_words->opt->file,
 891                        &style->ctx, style->newline,
 892                        diff_words->plus.text.ptr + diff_words->plus.text.size
 893                        - diff_words->current_plus, diff_words->current_plus,
 894                        line_prefix);
 895        }
 896        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 897}
 898
 899/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 900static void diff_words_flush(struct emit_callback *ecbdata)
 901{
 902        if (ecbdata->diff_words->minus.text.size ||
 903            ecbdata->diff_words->plus.text.size)
 904                diff_words_show(ecbdata->diff_words);
 905}
 906
 907static void free_diff_words_data(struct emit_callback *ecbdata)
 908{
 909        if (ecbdata->diff_words) {
 910                diff_words_flush(ecbdata);
 911                free (ecbdata->diff_words->minus.text.ptr);
 912                free (ecbdata->diff_words->minus.orig);
 913                free (ecbdata->diff_words->plus.text.ptr);
 914                free (ecbdata->diff_words->plus.orig);
 915                if (ecbdata->diff_words->word_regex) {
 916                        regfree(ecbdata->diff_words->word_regex);
 917                        free(ecbdata->diff_words->word_regex);
 918                }
 919                free(ecbdata->diff_words);
 920                ecbdata->diff_words = NULL;
 921        }
 922}
 923
 924const char *diff_get_color(int diff_use_color, enum color_diff ix)
 925{
 926        if (diff_use_color)
 927                return diff_colors[ix];
 928        return "";
 929}
 930
 931static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 932{
 933        const char *cp;
 934        unsigned long allot;
 935        size_t l = len;
 936
 937        if (ecb->truncate)
 938                return ecb->truncate(line, len);
 939        cp = line;
 940        allot = l;
 941        while (0 < l) {
 942                (void) utf8_width(&cp, &l);
 943                if (!cp)
 944                        break; /* truncated in the middle? */
 945        }
 946        return allot - l;
 947}
 948
 949static void find_lno(const char *line, struct emit_callback *ecbdata)
 950{
 951        const char *p;
 952        ecbdata->lno_in_preimage = 0;
 953        ecbdata->lno_in_postimage = 0;
 954        p = strchr(line, '-');
 955        if (!p)
 956                return; /* cannot happen */
 957        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 958        p = strchr(p, '+');
 959        if (!p)
 960                return; /* cannot happen */
 961        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 962}
 963
 964static void fn_out_consume(void *priv, char *line, unsigned long len)
 965{
 966        struct emit_callback *ecbdata = priv;
 967        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 968        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 969        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 970        struct diff_options *o = ecbdata->opt;
 971        char *line_prefix = "";
 972        struct strbuf *msgbuf;
 973
 974        if (o && o->output_prefix) {
 975                msgbuf = o->output_prefix(o, o->output_prefix_data);
 976                line_prefix = msgbuf->buf;
 977        }
 978
 979        if (ecbdata->header) {
 980                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 981                strbuf_reset(ecbdata->header);
 982                ecbdata->header = NULL;
 983        }
 984        *(ecbdata->found_changesp) = 1;
 985
 986        if (ecbdata->label_path[0]) {
 987                const char *name_a_tab, *name_b_tab;
 988
 989                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 990                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 991
 992                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
 993                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
 994                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
 995                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
 996                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 997        }
 998
 999        if (diff_suppress_blank_empty
1000            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1001                line[0] = '\n';
1002                len = 1;
1003        }
1004
1005        if (line[0] == '@') {
1006                if (ecbdata->diff_words)
1007                        diff_words_flush(ecbdata);
1008                len = sane_truncate_line(ecbdata, line, len);
1009                find_lno(line, ecbdata);
1010                emit_hunk_header(ecbdata, line, len);
1011                if (line[len-1] != '\n')
1012                        putc('\n', ecbdata->opt->file);
1013                return;
1014        }
1015
1016        if (len < 1) {
1017                emit_line(ecbdata->opt, reset, reset, line, len);
1018                if (ecbdata->diff_words
1019                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1020                        fputs("~\n", ecbdata->opt->file);
1021                return;
1022        }
1023
1024        if (ecbdata->diff_words) {
1025                if (line[0] == '-') {
1026                        diff_words_append(line, len,
1027                                          &ecbdata->diff_words->minus);
1028                        return;
1029                } else if (line[0] == '+') {
1030                        diff_words_append(line, len,
1031                                          &ecbdata->diff_words->plus);
1032                        return;
1033                }
1034                diff_words_flush(ecbdata);
1035                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1036                        emit_line(ecbdata->opt, plain, reset, line, len);
1037                        fputs("~\n", ecbdata->opt->file);
1038                } else {
1039                        /* don't print the prefix character */
1040                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1041                }
1042                return;
1043        }
1044
1045        if (line[0] != '+') {
1046                const char *color =
1047                        diff_get_color(ecbdata->color_diff,
1048                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1049                ecbdata->lno_in_preimage++;
1050                if (line[0] == ' ')
1051                        ecbdata->lno_in_postimage++;
1052                emit_line(ecbdata->opt, color, reset, line, len);
1053        } else {
1054                ecbdata->lno_in_postimage++;
1055                emit_add_line(reset, ecbdata, line + 1, len - 1);
1056        }
1057}
1058
1059static char *pprint_rename(const char *a, const char *b)
1060{
1061        const char *old = a;
1062        const char *new = b;
1063        struct strbuf name = STRBUF_INIT;
1064        int pfx_length, sfx_length;
1065        int len_a = strlen(a);
1066        int len_b = strlen(b);
1067        int a_midlen, b_midlen;
1068        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1069        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1070
1071        if (qlen_a || qlen_b) {
1072                quote_c_style(a, &name, NULL, 0);
1073                strbuf_addstr(&name, " => ");
1074                quote_c_style(b, &name, NULL, 0);
1075                return strbuf_detach(&name, NULL);
1076        }
1077
1078        /* Find common prefix */
1079        pfx_length = 0;
1080        while (*old && *new && *old == *new) {
1081                if (*old == '/')
1082                        pfx_length = old - a + 1;
1083                old++;
1084                new++;
1085        }
1086
1087        /* Find common suffix */
1088        old = a + len_a;
1089        new = b + len_b;
1090        sfx_length = 0;
1091        while (a <= old && b <= new && *old == *new) {
1092                if (*old == '/')
1093                        sfx_length = len_a - (old - a);
1094                old--;
1095                new--;
1096        }
1097
1098        /*
1099         * pfx{mid-a => mid-b}sfx
1100         * {pfx-a => pfx-b}sfx
1101         * pfx{sfx-a => sfx-b}
1102         * name-a => name-b
1103         */
1104        a_midlen = len_a - pfx_length - sfx_length;
1105        b_midlen = len_b - pfx_length - sfx_length;
1106        if (a_midlen < 0)
1107                a_midlen = 0;
1108        if (b_midlen < 0)
1109                b_midlen = 0;
1110
1111        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1112        if (pfx_length + sfx_length) {
1113                strbuf_add(&name, a, pfx_length);
1114                strbuf_addch(&name, '{');
1115        }
1116        strbuf_add(&name, a + pfx_length, a_midlen);
1117        strbuf_addstr(&name, " => ");
1118        strbuf_add(&name, b + pfx_length, b_midlen);
1119        if (pfx_length + sfx_length) {
1120                strbuf_addch(&name, '}');
1121                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1122        }
1123        return strbuf_detach(&name, NULL);
1124}
1125
1126struct diffstat_t {
1127        int nr;
1128        int alloc;
1129        struct diffstat_file {
1130                char *from_name;
1131                char *name;
1132                char *print_name;
1133                unsigned is_unmerged:1;
1134                unsigned is_binary:1;
1135                unsigned is_renamed:1;
1136                uintmax_t added, deleted;
1137        } **files;
1138};
1139
1140static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1141                                          const char *name_a,
1142                                          const char *name_b)
1143{
1144        struct diffstat_file *x;
1145        x = xcalloc(sizeof (*x), 1);
1146        if (diffstat->nr == diffstat->alloc) {
1147                diffstat->alloc = alloc_nr(diffstat->alloc);
1148                diffstat->files = xrealloc(diffstat->files,
1149                                diffstat->alloc * sizeof(x));
1150        }
1151        diffstat->files[diffstat->nr++] = x;
1152        if (name_b) {
1153                x->from_name = xstrdup(name_a);
1154                x->name = xstrdup(name_b);
1155                x->is_renamed = 1;
1156        }
1157        else {
1158                x->from_name = NULL;
1159                x->name = xstrdup(name_a);
1160        }
1161        return x;
1162}
1163
1164static void diffstat_consume(void *priv, char *line, unsigned long len)
1165{
1166        struct diffstat_t *diffstat = priv;
1167        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1168
1169        if (line[0] == '+')
1170                x->added++;
1171        else if (line[0] == '-')
1172                x->deleted++;
1173}
1174
1175const char mime_boundary_leader[] = "------------";
1176
1177static int scale_linear(int it, int width, int max_change)
1178{
1179        /*
1180         * make sure that at least one '-' is printed if there were deletions,
1181         * and likewise for '+'.
1182         */
1183        if (max_change < 2)
1184                return it;
1185        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1186}
1187
1188static void show_name(FILE *file,
1189                      const char *prefix, const char *name, int len)
1190{
1191        fprintf(file, " %s%-*s |", prefix, len, name);
1192}
1193
1194static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1195{
1196        if (cnt <= 0)
1197                return;
1198        fprintf(file, "%s", set);
1199        while (cnt--)
1200                putc(ch, file);
1201        fprintf(file, "%s", reset);
1202}
1203
1204static void fill_print_name(struct diffstat_file *file)
1205{
1206        char *pname;
1207
1208        if (file->print_name)
1209                return;
1210
1211        if (!file->is_renamed) {
1212                struct strbuf buf = STRBUF_INIT;
1213                if (quote_c_style(file->name, &buf, NULL, 0)) {
1214                        pname = strbuf_detach(&buf, NULL);
1215                } else {
1216                        pname = file->name;
1217                        strbuf_release(&buf);
1218                }
1219        } else {
1220                pname = pprint_rename(file->from_name, file->name);
1221        }
1222        file->print_name = pname;
1223}
1224
1225static void show_stats(struct diffstat_t *data, struct diff_options *options)
1226{
1227        int i, len, add, del, adds = 0, dels = 0;
1228        uintmax_t max_change = 0, max_len = 0;
1229        int total_files = data->nr;
1230        int width, name_width;
1231        const char *reset, *set, *add_c, *del_c;
1232        const char *line_prefix = "";
1233        struct strbuf *msg = NULL;
1234
1235        if (data->nr == 0)
1236                return;
1237
1238        if (options->output_prefix) {
1239                msg = options->output_prefix(options, options->output_prefix_data);
1240                line_prefix = msg->buf;
1241        }
1242
1243        width = options->stat_width ? options->stat_width : 80;
1244        name_width = options->stat_name_width ? options->stat_name_width : 50;
1245
1246        /* Sanity: give at least 5 columns to the graph,
1247         * but leave at least 10 columns for the name.
1248         */
1249        if (width < 25)
1250                width = 25;
1251        if (name_width < 10)
1252                name_width = 10;
1253        else if (width < name_width + 15)
1254                name_width = width - 15;
1255
1256        /* Find the longest filename and max number of changes */
1257        reset = diff_get_color_opt(options, DIFF_RESET);
1258        set   = diff_get_color_opt(options, DIFF_PLAIN);
1259        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1260        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1261
1262        for (i = 0; i < data->nr; i++) {
1263                struct diffstat_file *file = data->files[i];
1264                uintmax_t change = file->added + file->deleted;
1265                fill_print_name(file);
1266                len = strlen(file->print_name);
1267                if (max_len < len)
1268                        max_len = len;
1269
1270                if (file->is_binary || file->is_unmerged)
1271                        continue;
1272                if (max_change < change)
1273                        max_change = change;
1274        }
1275
1276        /* Compute the width of the graph part;
1277         * 10 is for one blank at the beginning of the line plus
1278         * " | count " between the name and the graph.
1279         *
1280         * From here on, name_width is the width of the name area,
1281         * and width is the width of the graph area.
1282         */
1283        name_width = (name_width < max_len) ? name_width : max_len;
1284        if (width < (name_width + 10) + max_change)
1285                width = width - (name_width + 10);
1286        else
1287                width = max_change;
1288
1289        for (i = 0; i < data->nr; i++) {
1290                const char *prefix = "";
1291                char *name = data->files[i]->print_name;
1292                uintmax_t added = data->files[i]->added;
1293                uintmax_t deleted = data->files[i]->deleted;
1294                int name_len;
1295
1296                /*
1297                 * "scale" the filename
1298                 */
1299                len = name_width;
1300                name_len = strlen(name);
1301                if (name_width < name_len) {
1302                        char *slash;
1303                        prefix = "...";
1304                        len -= 3;
1305                        name += name_len - len;
1306                        slash = strchr(name, '/');
1307                        if (slash)
1308                                name = slash;
1309                }
1310
1311                if (data->files[i]->is_binary) {
1312                        fprintf(options->file, "%s", line_prefix);
1313                        show_name(options->file, prefix, name, len);
1314                        fprintf(options->file, "  Bin ");
1315                        fprintf(options->file, "%s%"PRIuMAX"%s",
1316                                del_c, deleted, reset);
1317                        fprintf(options->file, " -> ");
1318                        fprintf(options->file, "%s%"PRIuMAX"%s",
1319                                add_c, added, reset);
1320                        fprintf(options->file, " bytes");
1321                        fprintf(options->file, "\n");
1322                        continue;
1323                }
1324                else if (data->files[i]->is_unmerged) {
1325                        fprintf(options->file, "%s", line_prefix);
1326                        show_name(options->file, prefix, name, len);
1327                        fprintf(options->file, "  Unmerged\n");
1328                        continue;
1329                }
1330                else if (!data->files[i]->is_renamed &&
1331                         (added + deleted == 0)) {
1332                        total_files--;
1333                        continue;
1334                }
1335
1336                /*
1337                 * scale the add/delete
1338                 */
1339                add = added;
1340                del = deleted;
1341                adds += add;
1342                dels += del;
1343
1344                if (width <= max_change) {
1345                        add = scale_linear(add, width, max_change);
1346                        del = scale_linear(del, width, max_change);
1347                }
1348                fprintf(options->file, "%s", line_prefix);
1349                show_name(options->file, prefix, name, len);
1350                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1351                                added + deleted ? " " : "");
1352                show_graph(options->file, '+', add, add_c, reset);
1353                show_graph(options->file, '-', del, del_c, reset);
1354                fprintf(options->file, "\n");
1355        }
1356        fprintf(options->file, "%s", line_prefix);
1357        fprintf(options->file,
1358               " %d files changed, %d insertions(+), %d deletions(-)\n",
1359               total_files, adds, dels);
1360}
1361
1362static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1363{
1364        int i, adds = 0, dels = 0, total_files = data->nr;
1365
1366        if (data->nr == 0)
1367                return;
1368
1369        for (i = 0; i < data->nr; i++) {
1370                if (!data->files[i]->is_binary &&
1371                    !data->files[i]->is_unmerged) {
1372                        int added = data->files[i]->added;
1373                        int deleted= data->files[i]->deleted;
1374                        if (!data->files[i]->is_renamed &&
1375                            (added + deleted == 0)) {
1376                                total_files--;
1377                        } else {
1378                                adds += added;
1379                                dels += deleted;
1380                        }
1381                }
1382        }
1383        if (options->output_prefix) {
1384                struct strbuf *msg = NULL;
1385                msg = options->output_prefix(options,
1386                                options->output_prefix_data);
1387                fprintf(options->file, "%s", msg->buf);
1388        }
1389        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1390               total_files, adds, dels);
1391}
1392
1393static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1394{
1395        int i;
1396
1397        if (data->nr == 0)
1398                return;
1399
1400        for (i = 0; i < data->nr; i++) {
1401                struct diffstat_file *file = data->files[i];
1402
1403                if (options->output_prefix) {
1404                        struct strbuf *msg = NULL;
1405                        msg = options->output_prefix(options,
1406                                        options->output_prefix_data);
1407                        fprintf(options->file, "%s", msg->buf);
1408                }
1409
1410                if (file->is_binary)
1411                        fprintf(options->file, "-\t-\t");
1412                else
1413                        fprintf(options->file,
1414                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1415                                file->added, file->deleted);
1416                if (options->line_termination) {
1417                        fill_print_name(file);
1418                        if (!file->is_renamed)
1419                                write_name_quoted(file->name, options->file,
1420                                                  options->line_termination);
1421                        else {
1422                                fputs(file->print_name, options->file);
1423                                putc(options->line_termination, options->file);
1424                        }
1425                } else {
1426                        if (file->is_renamed) {
1427                                putc('\0', options->file);
1428                                write_name_quoted(file->from_name, options->file, '\0');
1429                        }
1430                        write_name_quoted(file->name, options->file, '\0');
1431                }
1432        }
1433}
1434
1435struct dirstat_file {
1436        const char *name;
1437        unsigned long changed;
1438};
1439
1440struct dirstat_dir {
1441        struct dirstat_file *files;
1442        int alloc, nr, percent, cumulative;
1443};
1444
1445static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1446                unsigned long changed, const char *base, int baselen)
1447{
1448        unsigned long this_dir = 0;
1449        unsigned int sources = 0;
1450        const char *line_prefix = "";
1451        struct strbuf *msg = NULL;
1452
1453        if (opt->output_prefix) {
1454                msg = opt->output_prefix(opt, opt->output_prefix_data);
1455                line_prefix = msg->buf;
1456        }
1457
1458        while (dir->nr) {
1459                struct dirstat_file *f = dir->files;
1460                int namelen = strlen(f->name);
1461                unsigned long this;
1462                char *slash;
1463
1464                if (namelen < baselen)
1465                        break;
1466                if (memcmp(f->name, base, baselen))
1467                        break;
1468                slash = strchr(f->name + baselen, '/');
1469                if (slash) {
1470                        int newbaselen = slash + 1 - f->name;
1471                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1472                        sources++;
1473                } else {
1474                        this = f->changed;
1475                        dir->files++;
1476                        dir->nr--;
1477                        sources += 2;
1478                }
1479                this_dir += this;
1480        }
1481
1482        /*
1483         * We don't report dirstat's for
1484         *  - the top level
1485         *  - or cases where everything came from a single directory
1486         *    under this directory (sources == 1).
1487         */
1488        if (baselen && sources != 1) {
1489                int permille = this_dir * 1000 / changed;
1490                if (permille) {
1491                        int percent = permille / 10;
1492                        if (percent >= dir->percent) {
1493                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1494                                        percent, permille % 10, baselen, base);
1495                                if (!dir->cumulative)
1496                                        return 0;
1497                        }
1498                }
1499        }
1500        return this_dir;
1501}
1502
1503static int dirstat_compare(const void *_a, const void *_b)
1504{
1505        const struct dirstat_file *a = _a;
1506        const struct dirstat_file *b = _b;
1507        return strcmp(a->name, b->name);
1508}
1509
1510static void show_dirstat(struct diff_options *options)
1511{
1512        int i;
1513        unsigned long changed;
1514        struct dirstat_dir dir;
1515        struct diff_queue_struct *q = &diff_queued_diff;
1516
1517        dir.files = NULL;
1518        dir.alloc = 0;
1519        dir.nr = 0;
1520        dir.percent = options->dirstat_percent;
1521        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1522
1523        changed = 0;
1524        for (i = 0; i < q->nr; i++) {
1525                struct diff_filepair *p = q->queue[i];
1526                const char *name;
1527                unsigned long copied, added, damage;
1528
1529                name = p->one->path ? p->one->path : p->two->path;
1530
1531                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1532                        diff_populate_filespec(p->one, 0);
1533                        diff_populate_filespec(p->two, 0);
1534                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1535                                               &copied, &added);
1536                        diff_free_filespec_data(p->one);
1537                        diff_free_filespec_data(p->two);
1538                } else if (DIFF_FILE_VALID(p->one)) {
1539                        diff_populate_filespec(p->one, 1);
1540                        copied = added = 0;
1541                        diff_free_filespec_data(p->one);
1542                } else if (DIFF_FILE_VALID(p->two)) {
1543                        diff_populate_filespec(p->two, 1);
1544                        copied = 0;
1545                        added = p->two->size;
1546                        diff_free_filespec_data(p->two);
1547                } else
1548                        continue;
1549
1550                /*
1551                 * Original minus copied is the removed material,
1552                 * added is the new material.  They are both damages
1553                 * made to the preimage. In --dirstat-by-file mode, count
1554                 * damaged files, not damaged lines. This is done by
1555                 * counting only a single damaged line per file.
1556                 */
1557                damage = (p->one->size - copied) + added;
1558                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1559                        damage = 1;
1560
1561                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1562                dir.files[dir.nr].name = name;
1563                dir.files[dir.nr].changed = damage;
1564                changed += damage;
1565                dir.nr++;
1566        }
1567
1568        /* This can happen even with many files, if everything was renames */
1569        if (!changed)
1570                return;
1571
1572        /* Show all directories with more than x% of the changes */
1573        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1574        gather_dirstat(options, &dir, changed, "", 0);
1575}
1576
1577static void free_diffstat_info(struct diffstat_t *diffstat)
1578{
1579        int i;
1580        for (i = 0; i < diffstat->nr; i++) {
1581                struct diffstat_file *f = diffstat->files[i];
1582                if (f->name != f->print_name)
1583                        free(f->print_name);
1584                free(f->name);
1585                free(f->from_name);
1586                free(f);
1587        }
1588        free(diffstat->files);
1589}
1590
1591struct checkdiff_t {
1592        const char *filename;
1593        int lineno;
1594        int conflict_marker_size;
1595        struct diff_options *o;
1596        unsigned ws_rule;
1597        unsigned status;
1598};
1599
1600static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1601{
1602        char firstchar;
1603        int cnt;
1604
1605        if (len < marker_size + 1)
1606                return 0;
1607        firstchar = line[0];
1608        switch (firstchar) {
1609        case '=': case '>': case '<': case '|':
1610                break;
1611        default:
1612                return 0;
1613        }
1614        for (cnt = 1; cnt < marker_size; cnt++)
1615                if (line[cnt] != firstchar)
1616                        return 0;
1617        /* line[1] thru line[marker_size-1] are same as firstchar */
1618        if (len < marker_size + 1 || !isspace(line[marker_size]))
1619                return 0;
1620        return 1;
1621}
1622
1623static void checkdiff_consume(void *priv, char *line, unsigned long len)
1624{
1625        struct checkdiff_t *data = priv;
1626        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1627        int marker_size = data->conflict_marker_size;
1628        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1629        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1630        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1631        char *err;
1632        char *line_prefix = "";
1633        struct strbuf *msgbuf;
1634
1635        assert(data->o);
1636        if (data->o->output_prefix) {
1637                msgbuf = data->o->output_prefix(data->o,
1638                        data->o->output_prefix_data);
1639                line_prefix = msgbuf->buf;
1640        }
1641
1642        if (line[0] == '+') {
1643                unsigned bad;
1644                data->lineno++;
1645                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1646                        data->status |= 1;
1647                        fprintf(data->o->file,
1648                                "%s%s:%d: leftover conflict marker\n",
1649                                line_prefix, data->filename, data->lineno);
1650                }
1651                bad = ws_check(line + 1, len - 1, data->ws_rule);
1652                if (!bad)
1653                        return;
1654                data->status |= bad;
1655                err = whitespace_error_string(bad);
1656                fprintf(data->o->file, "%s%s:%d: %s.\n",
1657                        line_prefix, data->filename, data->lineno, err);
1658                free(err);
1659                emit_line(data->o, set, reset, line, 1);
1660                ws_check_emit(line + 1, len - 1, data->ws_rule,
1661                              data->o->file, set, reset, ws);
1662        } else if (line[0] == ' ') {
1663                data->lineno++;
1664        } else if (line[0] == '@') {
1665                char *plus = strchr(line, '+');
1666                if (plus)
1667                        data->lineno = strtol(plus, NULL, 10) - 1;
1668                else
1669                        die("invalid diff");
1670        }
1671}
1672
1673static unsigned char *deflate_it(char *data,
1674                                 unsigned long size,
1675                                 unsigned long *result_size)
1676{
1677        int bound;
1678        unsigned char *deflated;
1679        z_stream stream;
1680
1681        memset(&stream, 0, sizeof(stream));
1682        deflateInit(&stream, zlib_compression_level);
1683        bound = deflateBound(&stream, size);
1684        deflated = xmalloc(bound);
1685        stream.next_out = deflated;
1686        stream.avail_out = bound;
1687
1688        stream.next_in = (unsigned char *)data;
1689        stream.avail_in = size;
1690        while (deflate(&stream, Z_FINISH) == Z_OK)
1691                ; /* nothing */
1692        deflateEnd(&stream);
1693        *result_size = stream.total_out;
1694        return deflated;
1695}
1696
1697static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1698{
1699        void *cp;
1700        void *delta;
1701        void *deflated;
1702        void *data;
1703        unsigned long orig_size;
1704        unsigned long delta_size;
1705        unsigned long deflate_size;
1706        unsigned long data_size;
1707
1708        /* We could do deflated delta, or we could do just deflated two,
1709         * whichever is smaller.
1710         */
1711        delta = NULL;
1712        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1713        if (one->size && two->size) {
1714                delta = diff_delta(one->ptr, one->size,
1715                                   two->ptr, two->size,
1716                                   &delta_size, deflate_size);
1717                if (delta) {
1718                        void *to_free = delta;
1719                        orig_size = delta_size;
1720                        delta = deflate_it(delta, delta_size, &delta_size);
1721                        free(to_free);
1722                }
1723        }
1724
1725        if (delta && delta_size < deflate_size) {
1726                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1727                free(deflated);
1728                data = delta;
1729                data_size = delta_size;
1730        }
1731        else {
1732                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1733                free(delta);
1734                data = deflated;
1735                data_size = deflate_size;
1736        }
1737
1738        /* emit data encoded in base85 */
1739        cp = data;
1740        while (data_size) {
1741                int bytes = (52 < data_size) ? 52 : data_size;
1742                char line[70];
1743                data_size -= bytes;
1744                if (bytes <= 26)
1745                        line[0] = bytes + 'A' - 1;
1746                else
1747                        line[0] = bytes - 26 + 'a' - 1;
1748                encode_85(line + 1, cp, bytes);
1749                cp = (char *) cp + bytes;
1750                fprintf(file, "%s", prefix);
1751                fputs(line, file);
1752                fputc('\n', file);
1753        }
1754        fprintf(file, "%s\n", prefix);
1755        free(data);
1756}
1757
1758static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1759{
1760        fprintf(file, "%sGIT binary patch\n", prefix);
1761        emit_binary_diff_body(file, one, two, prefix);
1762        emit_binary_diff_body(file, two, one, prefix);
1763}
1764
1765static void diff_filespec_load_driver(struct diff_filespec *one)
1766{
1767        /* Use already-loaded driver */
1768        if (one->driver)
1769                return;
1770
1771        if (S_ISREG(one->mode))
1772                one->driver = userdiff_find_by_path(one->path);
1773
1774        /* Fallback to default settings */
1775        if (!one->driver)
1776                one->driver = userdiff_find_by_name("default");
1777}
1778
1779int diff_filespec_is_binary(struct diff_filespec *one)
1780{
1781        if (one->is_binary == -1) {
1782                diff_filespec_load_driver(one);
1783                if (one->driver->binary != -1)
1784                        one->is_binary = one->driver->binary;
1785                else {
1786                        if (!one->data && DIFF_FILE_VALID(one))
1787                                diff_populate_filespec(one, 0);
1788                        if (one->data)
1789                                one->is_binary = buffer_is_binary(one->data,
1790                                                one->size);
1791                        if (one->is_binary == -1)
1792                                one->is_binary = 0;
1793                }
1794        }
1795        return one->is_binary;
1796}
1797
1798static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1799{
1800        diff_filespec_load_driver(one);
1801        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1802}
1803
1804static const char *userdiff_word_regex(struct diff_filespec *one)
1805{
1806        diff_filespec_load_driver(one);
1807        return one->driver->word_regex;
1808}
1809
1810void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1811{
1812        if (!options->a_prefix)
1813                options->a_prefix = a;
1814        if (!options->b_prefix)
1815                options->b_prefix = b;
1816}
1817
1818struct userdiff_driver *get_textconv(struct diff_filespec *one)
1819{
1820        if (!DIFF_FILE_VALID(one))
1821                return NULL;
1822
1823        diff_filespec_load_driver(one);
1824        if (!one->driver->textconv)
1825                return NULL;
1826
1827        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1828                struct notes_cache *c = xmalloc(sizeof(*c));
1829                struct strbuf name = STRBUF_INIT;
1830
1831                strbuf_addf(&name, "textconv/%s", one->driver->name);
1832                notes_cache_init(c, name.buf, one->driver->textconv);
1833                one->driver->textconv_cache = c;
1834        }
1835
1836        return one->driver;
1837}
1838
1839static void builtin_diff(const char *name_a,
1840                         const char *name_b,
1841                         struct diff_filespec *one,
1842                         struct diff_filespec *two,
1843                         const char *xfrm_msg,
1844                         int must_show_header,
1845                         struct diff_options *o,
1846                         int complete_rewrite)
1847{
1848        mmfile_t mf1, mf2;
1849        const char *lbl[2];
1850        char *a_one, *b_two;
1851        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1852        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1853        const char *a_prefix, *b_prefix;
1854        struct userdiff_driver *textconv_one = NULL;
1855        struct userdiff_driver *textconv_two = NULL;
1856        struct strbuf header = STRBUF_INIT;
1857        struct strbuf *msgbuf;
1858        char *line_prefix = "";
1859
1860        if (o->output_prefix) {
1861                msgbuf = o->output_prefix(o, o->output_prefix_data);
1862                line_prefix = msgbuf->buf;
1863        }
1864
1865        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1866                        (!one->mode || S_ISGITLINK(one->mode)) &&
1867                        (!two->mode || S_ISGITLINK(two->mode))) {
1868                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1869                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1870                show_submodule_summary(o->file, one ? one->path : two->path,
1871                                one->sha1, two->sha1, two->dirty_submodule,
1872                                del, add, reset);
1873                return;
1874        }
1875
1876        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1877                textconv_one = get_textconv(one);
1878                textconv_two = get_textconv(two);
1879        }
1880
1881        diff_set_mnemonic_prefix(o, "a/", "b/");
1882        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1883                a_prefix = o->b_prefix;
1884                b_prefix = o->a_prefix;
1885        } else {
1886                a_prefix = o->a_prefix;
1887                b_prefix = o->b_prefix;
1888        }
1889
1890        /* Never use a non-valid filename anywhere if at all possible */
1891        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1892        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1893
1894        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1895        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1896        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1897        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1898        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1899        if (lbl[0][0] == '/') {
1900                /* /dev/null */
1901                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1902                if (xfrm_msg)
1903                        strbuf_addstr(&header, xfrm_msg);
1904                must_show_header = 1;
1905        }
1906        else if (lbl[1][0] == '/') {
1907                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1908                if (xfrm_msg)
1909                        strbuf_addstr(&header, xfrm_msg);
1910                must_show_header = 1;
1911        }
1912        else {
1913                if (one->mode != two->mode) {
1914                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1915                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1916                        must_show_header = 1;
1917                }
1918                if (xfrm_msg)
1919                        strbuf_addstr(&header, xfrm_msg);
1920
1921                /*
1922                 * we do not run diff between different kind
1923                 * of objects.
1924                 */
1925                if ((one->mode ^ two->mode) & S_IFMT)
1926                        goto free_ab_and_return;
1927                if (complete_rewrite &&
1928                    (textconv_one || !diff_filespec_is_binary(one)) &&
1929                    (textconv_two || !diff_filespec_is_binary(two))) {
1930                        fprintf(o->file, "%s", header.buf);
1931                        strbuf_reset(&header);
1932                        emit_rewrite_diff(name_a, name_b, one, two,
1933                                                textconv_one, textconv_two, o);
1934                        o->found_changes = 1;
1935                        goto free_ab_and_return;
1936                }
1937        }
1938
1939        if (!DIFF_OPT_TST(o, TEXT) &&
1940            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1941              (!textconv_two && diff_filespec_is_binary(two)) )) {
1942                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1943                        die("unable to read files to diff");
1944                /* Quite common confusing case */
1945                if (mf1.size == mf2.size &&
1946                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1947                        if (must_show_header)
1948                                fprintf(o->file, "%s", header.buf);
1949                        goto free_ab_and_return;
1950                }
1951                fprintf(o->file, "%s", header.buf);
1952                strbuf_reset(&header);
1953                if (DIFF_OPT_TST(o, BINARY))
1954                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1955                else
1956                        fprintf(o->file, "%sBinary files %s and %s differ\n",
1957                                line_prefix, lbl[0], lbl[1]);
1958                o->found_changes = 1;
1959        }
1960        else {
1961                /* Crazy xdl interfaces.. */
1962                const char *diffopts = getenv("GIT_DIFF_OPTS");
1963                xpparam_t xpp;
1964                xdemitconf_t xecfg;
1965                struct emit_callback ecbdata;
1966                const struct userdiff_funcname *pe;
1967
1968                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
1969                        fprintf(o->file, "%s", header.buf);
1970                        strbuf_reset(&header);
1971                }
1972
1973                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1974                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1975
1976                pe = diff_funcname_pattern(one);
1977                if (!pe)
1978                        pe = diff_funcname_pattern(two);
1979
1980                memset(&xpp, 0, sizeof(xpp));
1981                memset(&xecfg, 0, sizeof(xecfg));
1982                memset(&ecbdata, 0, sizeof(ecbdata));
1983                ecbdata.label_path = lbl;
1984                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1985                ecbdata.found_changesp = &o->found_changes;
1986                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1987                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1988                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1989                ecbdata.opt = o;
1990                ecbdata.header = header.len ? &header : NULL;
1991                xpp.flags = o->xdl_opts;
1992                xecfg.ctxlen = o->context;
1993                xecfg.interhunkctxlen = o->interhunkcontext;
1994                xecfg.flags = XDL_EMIT_FUNCNAMES;
1995                if (pe)
1996                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1997                if (!diffopts)
1998                        ;
1999                else if (!prefixcmp(diffopts, "--unified="))
2000                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
2001                else if (!prefixcmp(diffopts, "-u"))
2002                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
2003                if (o->word_diff) {
2004                        int i;
2005
2006                        ecbdata.diff_words =
2007                                xcalloc(1, sizeof(struct diff_words_data));
2008                        ecbdata.diff_words->type = o->word_diff;
2009                        ecbdata.diff_words->opt = o;
2010                        if (!o->word_regex)
2011                                o->word_regex = userdiff_word_regex(one);
2012                        if (!o->word_regex)
2013                                o->word_regex = userdiff_word_regex(two);
2014                        if (!o->word_regex)
2015                                o->word_regex = diff_word_regex_cfg;
2016                        if (o->word_regex) {
2017                                ecbdata.diff_words->word_regex = (regex_t *)
2018                                        xmalloc(sizeof(regex_t));
2019                                if (regcomp(ecbdata.diff_words->word_regex,
2020                                                o->word_regex,
2021                                                REG_EXTENDED | REG_NEWLINE))
2022                                        die ("Invalid regular expression: %s",
2023                                                        o->word_regex);
2024                        }
2025                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2026                                if (o->word_diff == diff_words_styles[i].type) {
2027                                        ecbdata.diff_words->style =
2028                                                &diff_words_styles[i];
2029                                        break;
2030                                }
2031                        }
2032                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2033                                struct diff_words_style *st = ecbdata.diff_words->style;
2034                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2035                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2036                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2037                        }
2038                }
2039                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2040                              &xpp, &xecfg);
2041                if (o->word_diff)
2042                        free_diff_words_data(&ecbdata);
2043                if (textconv_one)
2044                        free(mf1.ptr);
2045                if (textconv_two)
2046                        free(mf2.ptr);
2047                xdiff_clear_find_func(&xecfg);
2048        }
2049
2050 free_ab_and_return:
2051        strbuf_release(&header);
2052        diff_free_filespec_data(one);
2053        diff_free_filespec_data(two);
2054        free(a_one);
2055        free(b_two);
2056        return;
2057}
2058
2059static void builtin_diffstat(const char *name_a, const char *name_b,
2060                             struct diff_filespec *one,
2061                             struct diff_filespec *two,
2062                             struct diffstat_t *diffstat,
2063                             struct diff_options *o,
2064                             int complete_rewrite)
2065{
2066        mmfile_t mf1, mf2;
2067        struct diffstat_file *data;
2068
2069        data = diffstat_add(diffstat, name_a, name_b);
2070
2071        if (!one || !two) {
2072                data->is_unmerged = 1;
2073                return;
2074        }
2075        if (complete_rewrite) {
2076                diff_populate_filespec(one, 0);
2077                diff_populate_filespec(two, 0);
2078                data->deleted = count_lines(one->data, one->size);
2079                data->added = count_lines(two->data, two->size);
2080                goto free_and_return;
2081        }
2082        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2083                die("unable to read files to diff");
2084
2085        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2086                data->is_binary = 1;
2087                data->added = mf2.size;
2088                data->deleted = mf1.size;
2089        } else {
2090                /* Crazy xdl interfaces.. */
2091                xpparam_t xpp;
2092                xdemitconf_t xecfg;
2093
2094                memset(&xpp, 0, sizeof(xpp));
2095                memset(&xecfg, 0, sizeof(xecfg));
2096                xpp.flags = o->xdl_opts;
2097                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2098                              &xpp, &xecfg);
2099        }
2100
2101 free_and_return:
2102        diff_free_filespec_data(one);
2103        diff_free_filespec_data(two);
2104}
2105
2106static void builtin_checkdiff(const char *name_a, const char *name_b,
2107                              const char *attr_path,
2108                              struct diff_filespec *one,
2109                              struct diff_filespec *two,
2110                              struct diff_options *o)
2111{
2112        mmfile_t mf1, mf2;
2113        struct checkdiff_t data;
2114
2115        if (!two)
2116                return;
2117
2118        memset(&data, 0, sizeof(data));
2119        data.filename = name_b ? name_b : name_a;
2120        data.lineno = 0;
2121        data.o = o;
2122        data.ws_rule = whitespace_rule(attr_path);
2123        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2124
2125        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2126                die("unable to read files to diff");
2127
2128        /*
2129         * All the other codepaths check both sides, but not checking
2130         * the "old" side here is deliberate.  We are checking the newly
2131         * introduced changes, and as long as the "new" side is text, we
2132         * can and should check what it introduces.
2133         */
2134        if (diff_filespec_is_binary(two))
2135                goto free_and_return;
2136        else {
2137                /* Crazy xdl interfaces.. */
2138                xpparam_t xpp;
2139                xdemitconf_t xecfg;
2140
2141                memset(&xpp, 0, sizeof(xpp));
2142                memset(&xecfg, 0, sizeof(xecfg));
2143                xecfg.ctxlen = 1; /* at least one context line */
2144                xpp.flags = 0;
2145                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2146                              &xpp, &xecfg);
2147
2148                if (data.ws_rule & WS_BLANK_AT_EOF) {
2149                        struct emit_callback ecbdata;
2150                        int blank_at_eof;
2151
2152                        ecbdata.ws_rule = data.ws_rule;
2153                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2154                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
2155
2156                        if (blank_at_eof) {
2157                                static char *err;
2158                                if (!err)
2159                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2160                                fprintf(o->file, "%s:%d: %s.\n",
2161                                        data.filename, blank_at_eof, err);
2162                                data.status = 1; /* report errors */
2163                        }
2164                }
2165        }
2166 free_and_return:
2167        diff_free_filespec_data(one);
2168        diff_free_filespec_data(two);
2169        if (data.status)
2170                DIFF_OPT_SET(o, CHECK_FAILED);
2171}
2172
2173struct diff_filespec *alloc_filespec(const char *path)
2174{
2175        int namelen = strlen(path);
2176        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2177
2178        memset(spec, 0, sizeof(*spec));
2179        spec->path = (char *)(spec + 1);
2180        memcpy(spec->path, path, namelen+1);
2181        spec->count = 1;
2182        spec->is_binary = -1;
2183        return spec;
2184}
2185
2186void free_filespec(struct diff_filespec *spec)
2187{
2188        if (!--spec->count) {
2189                diff_free_filespec_data(spec);
2190                free(spec);
2191        }
2192}
2193
2194void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2195                   unsigned short mode)
2196{
2197        if (mode) {
2198                spec->mode = canon_mode(mode);
2199                hashcpy(spec->sha1, sha1);
2200                spec->sha1_valid = !is_null_sha1(sha1);
2201        }
2202}
2203
2204/*
2205 * Given a name and sha1 pair, if the index tells us the file in
2206 * the work tree has that object contents, return true, so that
2207 * prepare_temp_file() does not have to inflate and extract.
2208 */
2209static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2210{
2211        struct cache_entry *ce;
2212        struct stat st;
2213        int pos, len;
2214
2215        /*
2216         * We do not read the cache ourselves here, because the
2217         * benchmark with my previous version that always reads cache
2218         * shows that it makes things worse for diff-tree comparing
2219         * two linux-2.6 kernel trees in an already checked out work
2220         * tree.  This is because most diff-tree comparisons deal with
2221         * only a small number of files, while reading the cache is
2222         * expensive for a large project, and its cost outweighs the
2223         * savings we get by not inflating the object to a temporary
2224         * file.  Practically, this code only helps when we are used
2225         * by diff-cache --cached, which does read the cache before
2226         * calling us.
2227         */
2228        if (!active_cache)
2229                return 0;
2230
2231        /* We want to avoid the working directory if our caller
2232         * doesn't need the data in a normal file, this system
2233         * is rather slow with its stat/open/mmap/close syscalls,
2234         * and the object is contained in a pack file.  The pack
2235         * is probably already open and will be faster to obtain
2236         * the data through than the working directory.  Loose
2237         * objects however would tend to be slower as they need
2238         * to be individually opened and inflated.
2239         */
2240        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2241                return 0;
2242
2243        len = strlen(name);
2244        pos = cache_name_pos(name, len);
2245        if (pos < 0)
2246                return 0;
2247        ce = active_cache[pos];
2248
2249        /*
2250         * This is not the sha1 we are looking for, or
2251         * unreusable because it is not a regular file.
2252         */
2253        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2254                return 0;
2255
2256        /*
2257         * If ce is marked as "assume unchanged", there is no
2258         * guarantee that work tree matches what we are looking for.
2259         */
2260        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2261                return 0;
2262
2263        /*
2264         * If ce matches the file in the work tree, we can reuse it.
2265         */
2266        if (ce_uptodate(ce) ||
2267            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2268                return 1;
2269
2270        return 0;
2271}
2272
2273static int populate_from_stdin(struct diff_filespec *s)
2274{
2275        struct strbuf buf = STRBUF_INIT;
2276        size_t size = 0;
2277
2278        if (strbuf_read(&buf, 0, 0) < 0)
2279                return error("error while reading from stdin %s",
2280                                     strerror(errno));
2281
2282        s->should_munmap = 0;
2283        s->data = strbuf_detach(&buf, &size);
2284        s->size = size;
2285        s->should_free = 1;
2286        return 0;
2287}
2288
2289static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2290{
2291        int len;
2292        char *data = xmalloc(100), *dirty = "";
2293
2294        /* Are we looking at the work tree? */
2295        if (s->dirty_submodule)
2296                dirty = "-dirty";
2297
2298        len = snprintf(data, 100,
2299                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2300        s->data = data;
2301        s->size = len;
2302        s->should_free = 1;
2303        if (size_only) {
2304                s->data = NULL;
2305                free(data);
2306        }
2307        return 0;
2308}
2309
2310/*
2311 * While doing rename detection and pickaxe operation, we may need to
2312 * grab the data for the blob (or file) for our own in-core comparison.
2313 * diff_filespec has data and size fields for this purpose.
2314 */
2315int diff_populate_filespec(struct diff_filespec *s, int size_only)
2316{
2317        int err = 0;
2318        if (!DIFF_FILE_VALID(s))
2319                die("internal error: asking to populate invalid file.");
2320        if (S_ISDIR(s->mode))
2321                return -1;
2322
2323        if (s->data)
2324                return 0;
2325
2326        if (size_only && 0 < s->size)
2327                return 0;
2328
2329        if (S_ISGITLINK(s->mode))
2330                return diff_populate_gitlink(s, size_only);
2331
2332        if (!s->sha1_valid ||
2333            reuse_worktree_file(s->path, s->sha1, 0)) {
2334                struct strbuf buf = STRBUF_INIT;
2335                struct stat st;
2336                int fd;
2337
2338                if (!strcmp(s->path, "-"))
2339                        return populate_from_stdin(s);
2340
2341                if (lstat(s->path, &st) < 0) {
2342                        if (errno == ENOENT) {
2343                        err_empty:
2344                                err = -1;
2345                        empty:
2346                                s->data = (char *)"";
2347                                s->size = 0;
2348                                return err;
2349                        }
2350                }
2351                s->size = xsize_t(st.st_size);
2352                if (!s->size)
2353                        goto empty;
2354                if (S_ISLNK(st.st_mode)) {
2355                        struct strbuf sb = STRBUF_INIT;
2356
2357                        if (strbuf_readlink(&sb, s->path, s->size))
2358                                goto err_empty;
2359                        s->size = sb.len;
2360                        s->data = strbuf_detach(&sb, NULL);
2361                        s->should_free = 1;
2362                        return 0;
2363                }
2364                if (size_only)
2365                        return 0;
2366                fd = open(s->path, O_RDONLY);
2367                if (fd < 0)
2368                        goto err_empty;
2369                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2370                close(fd);
2371                s->should_munmap = 1;
2372
2373                /*
2374                 * Convert from working tree format to canonical git format
2375                 */
2376                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2377                        size_t size = 0;
2378                        munmap(s->data, s->size);
2379                        s->should_munmap = 0;
2380                        s->data = strbuf_detach(&buf, &size);
2381                        s->size = size;
2382                        s->should_free = 1;
2383                }
2384        }
2385        else {
2386                enum object_type type;
2387                if (size_only)
2388                        type = sha1_object_info(s->sha1, &s->size);
2389                else {
2390                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2391                        s->should_free = 1;
2392                }
2393        }
2394        return 0;
2395}
2396
2397void diff_free_filespec_blob(struct diff_filespec *s)
2398{
2399        if (s->should_free)
2400                free(s->data);
2401        else if (s->should_munmap)
2402                munmap(s->data, s->size);
2403
2404        if (s->should_free || s->should_munmap) {
2405                s->should_free = s->should_munmap = 0;
2406                s->data = NULL;
2407        }
2408}
2409
2410void diff_free_filespec_data(struct diff_filespec *s)
2411{
2412        diff_free_filespec_blob(s);
2413        free(s->cnt_data);
2414        s->cnt_data = NULL;
2415}
2416
2417static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2418                           void *blob,
2419                           unsigned long size,
2420                           const unsigned char *sha1,
2421                           int mode)
2422{
2423        int fd;
2424        struct strbuf buf = STRBUF_INIT;
2425        struct strbuf template = STRBUF_INIT;
2426        char *path_dup = xstrdup(path);
2427        const char *base = basename(path_dup);
2428
2429        /* Generate "XXXXXX_basename.ext" */
2430        strbuf_addstr(&template, "XXXXXX_");
2431        strbuf_addstr(&template, base);
2432
2433        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2434                        strlen(base) + 1);
2435        if (fd < 0)
2436                die_errno("unable to create temp-file");
2437        if (convert_to_working_tree(path,
2438                        (const char *)blob, (size_t)size, &buf)) {
2439                blob = buf.buf;
2440                size = buf.len;
2441        }
2442        if (write_in_full(fd, blob, size) != size)
2443                die_errno("unable to write temp-file");
2444        close(fd);
2445        temp->name = temp->tmp_path;
2446        strcpy(temp->hex, sha1_to_hex(sha1));
2447        temp->hex[40] = 0;
2448        sprintf(temp->mode, "%06o", mode);
2449        strbuf_release(&buf);
2450        strbuf_release(&template);
2451        free(path_dup);
2452}
2453
2454static struct diff_tempfile *prepare_temp_file(const char *name,
2455                struct diff_filespec *one)
2456{
2457        struct diff_tempfile *temp = claim_diff_tempfile();
2458
2459        if (!DIFF_FILE_VALID(one)) {
2460        not_a_valid_file:
2461                /* A '-' entry produces this for file-2, and
2462                 * a '+' entry produces this for file-1.
2463                 */
2464                temp->name = "/dev/null";
2465                strcpy(temp->hex, ".");
2466                strcpy(temp->mode, ".");
2467                return temp;
2468        }
2469
2470        if (!remove_tempfile_installed) {
2471                atexit(remove_tempfile);
2472                sigchain_push_common(remove_tempfile_on_signal);
2473                remove_tempfile_installed = 1;
2474        }
2475
2476        if (!one->sha1_valid ||
2477            reuse_worktree_file(name, one->sha1, 1)) {
2478                struct stat st;
2479                if (lstat(name, &st) < 0) {
2480                        if (errno == ENOENT)
2481                                goto not_a_valid_file;
2482                        die_errno("stat(%s)", name);
2483                }
2484                if (S_ISLNK(st.st_mode)) {
2485                        struct strbuf sb = STRBUF_INIT;
2486                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2487                                die_errno("readlink(%s)", name);
2488                        prep_temp_blob(name, temp, sb.buf, sb.len,
2489                                       (one->sha1_valid ?
2490                                        one->sha1 : null_sha1),
2491                                       (one->sha1_valid ?
2492                                        one->mode : S_IFLNK));
2493                        strbuf_release(&sb);
2494                }
2495                else {
2496                        /* we can borrow from the file in the work tree */
2497                        temp->name = name;
2498                        if (!one->sha1_valid)
2499                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2500                        else
2501                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2502                        /* Even though we may sometimes borrow the
2503                         * contents from the work tree, we always want
2504                         * one->mode.  mode is trustworthy even when
2505                         * !(one->sha1_valid), as long as
2506                         * DIFF_FILE_VALID(one).
2507                         */
2508                        sprintf(temp->mode, "%06o", one->mode);
2509                }
2510                return temp;
2511        }
2512        else {
2513                if (diff_populate_filespec(one, 0))
2514                        die("cannot read data blob for %s", one->path);
2515                prep_temp_blob(name, temp, one->data, one->size,
2516                               one->sha1, one->mode);
2517        }
2518        return temp;
2519}
2520
2521/* An external diff command takes:
2522 *
2523 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2524 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2525 *
2526 */
2527static void run_external_diff(const char *pgm,
2528                              const char *name,
2529                              const char *other,
2530                              struct diff_filespec *one,
2531                              struct diff_filespec *two,
2532                              const char *xfrm_msg,
2533                              int complete_rewrite)
2534{
2535        const char *spawn_arg[10];
2536        int retval;
2537        const char **arg = &spawn_arg[0];
2538
2539        if (one && two) {
2540                struct diff_tempfile *temp_one, *temp_two;
2541                const char *othername = (other ? other : name);
2542                temp_one = prepare_temp_file(name, one);
2543                temp_two = prepare_temp_file(othername, two);
2544                *arg++ = pgm;
2545                *arg++ = name;
2546                *arg++ = temp_one->name;
2547                *arg++ = temp_one->hex;
2548                *arg++ = temp_one->mode;
2549                *arg++ = temp_two->name;
2550                *arg++ = temp_two->hex;
2551                *arg++ = temp_two->mode;
2552                if (other) {
2553                        *arg++ = other;
2554                        *arg++ = xfrm_msg;
2555                }
2556        } else {
2557                *arg++ = pgm;
2558                *arg++ = name;
2559        }
2560        *arg = NULL;
2561        fflush(NULL);
2562        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2563        remove_tempfile();
2564        if (retval) {
2565                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2566                exit(1);
2567        }
2568}
2569
2570static int similarity_index(struct diff_filepair *p)
2571{
2572        return p->score * 100 / MAX_SCORE;
2573}
2574
2575static void fill_metainfo(struct strbuf *msg,
2576                          const char *name,
2577                          const char *other,
2578                          struct diff_filespec *one,
2579                          struct diff_filespec *two,
2580                          struct diff_options *o,
2581                          struct diff_filepair *p,
2582                          int *must_show_header,
2583                          int use_color)
2584{
2585        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2586        const char *reset = diff_get_color(use_color, DIFF_RESET);
2587        struct strbuf *msgbuf;
2588        char *line_prefix = "";
2589
2590        *must_show_header = 1;
2591        if (o->output_prefix) {
2592                msgbuf = o->output_prefix(o, o->output_prefix_data);
2593                line_prefix = msgbuf->buf;
2594        }
2595        strbuf_init(msg, PATH_MAX * 2 + 300);
2596        switch (p->status) {
2597        case DIFF_STATUS_COPIED:
2598                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2599                            line_prefix, set, similarity_index(p));
2600                strbuf_addf(msg, "%s\n%s%scopy from ",
2601                            reset,  line_prefix, set);
2602                quote_c_style(name, msg, NULL, 0);
2603                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2604                quote_c_style(other, msg, NULL, 0);
2605                strbuf_addf(msg, "%s\n", reset);
2606                break;
2607        case DIFF_STATUS_RENAMED:
2608                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2609                            line_prefix, set, similarity_index(p));
2610                strbuf_addf(msg, "%s\n%s%srename from ",
2611                            reset, line_prefix, set);
2612                quote_c_style(name, msg, NULL, 0);
2613                strbuf_addf(msg, "%s\n%s%srename to ",
2614                            reset, line_prefix, set);
2615                quote_c_style(other, msg, NULL, 0);
2616                strbuf_addf(msg, "%s\n", reset);
2617                break;
2618        case DIFF_STATUS_MODIFIED:
2619                if (p->score) {
2620                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2621                                    line_prefix,
2622                                    set, similarity_index(p), reset);
2623                        break;
2624                }
2625                /* fallthru */
2626        default:
2627                *must_show_header = 0;
2628        }
2629        if (one && two && hashcmp(one->sha1, two->sha1)) {
2630                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2631
2632                if (DIFF_OPT_TST(o, BINARY)) {
2633                        mmfile_t mf;
2634                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2635                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2636                                abbrev = 40;
2637                }
2638                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2639                            find_unique_abbrev(one->sha1, abbrev));
2640                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2641                if (one->mode == two->mode)
2642                        strbuf_addf(msg, " %06o", one->mode);
2643                strbuf_addf(msg, "%s\n", reset);
2644        }
2645}
2646
2647static void run_diff_cmd(const char *pgm,
2648                         const char *name,
2649                         const char *other,
2650                         const char *attr_path,
2651                         struct diff_filespec *one,
2652                         struct diff_filespec *two,
2653                         struct strbuf *msg,
2654                         struct diff_options *o,
2655                         struct diff_filepair *p)
2656{
2657        const char *xfrm_msg = NULL;
2658        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2659        int must_show_header = 0;
2660
2661        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2662                pgm = NULL;
2663        else {
2664                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2665                if (drv && drv->external)
2666                        pgm = drv->external;
2667        }
2668
2669        if (msg) {
2670                /*
2671                 * don't use colors when the header is intended for an
2672                 * external diff driver
2673                 */
2674                fill_metainfo(msg, name, other, one, two, o, p,
2675                              &must_show_header,
2676                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2677                xfrm_msg = msg->len ? msg->buf : NULL;
2678        }
2679
2680        if (pgm) {
2681                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2682                                  complete_rewrite);
2683                return;
2684        }
2685        if (one && two)
2686                builtin_diff(name, other ? other : name,
2687                             one, two, xfrm_msg, must_show_header,
2688                             o, complete_rewrite);
2689        else
2690                fprintf(o->file, "* Unmerged path %s\n", name);
2691}
2692
2693static void diff_fill_sha1_info(struct diff_filespec *one)
2694{
2695        if (DIFF_FILE_VALID(one)) {
2696                if (!one->sha1_valid) {
2697                        struct stat st;
2698                        if (!strcmp(one->path, "-")) {
2699                                hashcpy(one->sha1, null_sha1);
2700                                return;
2701                        }
2702                        if (lstat(one->path, &st) < 0)
2703                                die_errno("stat '%s'", one->path);
2704                        if (index_path(one->sha1, one->path, &st, 0))
2705                                die("cannot hash %s", one->path);
2706                }
2707        }
2708        else
2709                hashclr(one->sha1);
2710}
2711
2712static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2713{
2714        /* Strip the prefix but do not molest /dev/null and absolute paths */
2715        if (*namep && **namep != '/') {
2716                *namep += prefix_length;
2717                if (**namep == '/')
2718                        ++*namep;
2719        }
2720        if (*otherp && **otherp != '/') {
2721                *otherp += prefix_length;
2722                if (**otherp == '/')
2723                        ++*otherp;
2724        }
2725}
2726
2727static void run_diff(struct diff_filepair *p, struct diff_options *o)
2728{
2729        const char *pgm = external_diff();
2730        struct strbuf msg;
2731        struct diff_filespec *one = p->one;
2732        struct diff_filespec *two = p->two;
2733        const char *name;
2734        const char *other;
2735        const char *attr_path;
2736
2737        name  = p->one->path;
2738        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2739        attr_path = name;
2740        if (o->prefix_length)
2741                strip_prefix(o->prefix_length, &name, &other);
2742
2743        if (DIFF_PAIR_UNMERGED(p)) {
2744                run_diff_cmd(pgm, name, NULL, attr_path,
2745                             NULL, NULL, NULL, o, p);
2746                return;
2747        }
2748
2749        diff_fill_sha1_info(one);
2750        diff_fill_sha1_info(two);
2751
2752        if (!pgm &&
2753            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2754            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2755                /*
2756                 * a filepair that changes between file and symlink
2757                 * needs to be split into deletion and creation.
2758                 */
2759                struct diff_filespec *null = alloc_filespec(two->path);
2760                run_diff_cmd(NULL, name, other, attr_path,
2761                             one, null, &msg, o, p);
2762                free(null);
2763                strbuf_release(&msg);
2764
2765                null = alloc_filespec(one->path);
2766                run_diff_cmd(NULL, name, other, attr_path,
2767                             null, two, &msg, o, p);
2768                free(null);
2769        }
2770        else
2771                run_diff_cmd(pgm, name, other, attr_path,
2772                             one, two, &msg, o, p);
2773
2774        strbuf_release(&msg);
2775}
2776
2777static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2778                         struct diffstat_t *diffstat)
2779{
2780        const char *name;
2781        const char *other;
2782        int complete_rewrite = 0;
2783
2784        if (DIFF_PAIR_UNMERGED(p)) {
2785                /* unmerged */
2786                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2787                return;
2788        }
2789
2790        name = p->one->path;
2791        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2792
2793        if (o->prefix_length)
2794                strip_prefix(o->prefix_length, &name, &other);
2795
2796        diff_fill_sha1_info(p->one);
2797        diff_fill_sha1_info(p->two);
2798
2799        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2800                complete_rewrite = 1;
2801        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2802}
2803
2804static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2805{
2806        const char *name;
2807        const char *other;
2808        const char *attr_path;
2809
2810        if (DIFF_PAIR_UNMERGED(p)) {
2811                /* unmerged */
2812                return;
2813        }
2814
2815        name = p->one->path;
2816        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2817        attr_path = other ? other : name;
2818
2819        if (o->prefix_length)
2820                strip_prefix(o->prefix_length, &name, &other);
2821
2822        diff_fill_sha1_info(p->one);
2823        diff_fill_sha1_info(p->two);
2824
2825        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2826}
2827
2828void diff_setup(struct diff_options *options)
2829{
2830        memset(options, 0, sizeof(*options));
2831
2832        options->file = stdout;
2833
2834        options->line_termination = '\n';
2835        options->break_opt = -1;
2836        options->rename_limit = -1;
2837        options->dirstat_percent = 3;
2838        options->context = 3;
2839
2840        options->change = diff_change;
2841        options->add_remove = diff_addremove;
2842        if (diff_use_color_default > 0)
2843                DIFF_OPT_SET(options, COLOR_DIFF);
2844        options->detect_rename = diff_detect_rename_default;
2845
2846        if (diff_no_prefix) {
2847                options->a_prefix = options->b_prefix = "";
2848        } else if (!diff_mnemonic_prefix) {
2849                options->a_prefix = "a/";
2850                options->b_prefix = "b/";
2851        }
2852}
2853
2854int diff_setup_done(struct diff_options *options)
2855{
2856        int count = 0;
2857
2858        if (options->output_format & DIFF_FORMAT_NAME)
2859                count++;
2860        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2861                count++;
2862        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2863                count++;
2864        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2865                count++;
2866        if (count > 1)
2867                die("--name-only, --name-status, --check and -s are mutually exclusive");
2868
2869        /*
2870         * Most of the time we can say "there are changes"
2871         * only by checking if there are changed paths, but
2872         * --ignore-whitespace* options force us to look
2873         * inside contents.
2874         */
2875
2876        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2877            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2878            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2879                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2880        else
2881                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2882
2883        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2884                options->detect_rename = DIFF_DETECT_COPY;
2885
2886        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2887                options->prefix = NULL;
2888        if (options->prefix)
2889                options->prefix_length = strlen(options->prefix);
2890        else
2891                options->prefix_length = 0;
2892
2893        if (options->output_format & (DIFF_FORMAT_NAME |
2894                                      DIFF_FORMAT_NAME_STATUS |
2895                                      DIFF_FORMAT_CHECKDIFF |
2896                                      DIFF_FORMAT_NO_OUTPUT))
2897                options->output_format &= ~(DIFF_FORMAT_RAW |
2898                                            DIFF_FORMAT_NUMSTAT |
2899                                            DIFF_FORMAT_DIFFSTAT |
2900                                            DIFF_FORMAT_SHORTSTAT |
2901                                            DIFF_FORMAT_DIRSTAT |
2902                                            DIFF_FORMAT_SUMMARY |
2903                                            DIFF_FORMAT_PATCH);
2904
2905        /*
2906         * These cases always need recursive; we do not drop caller-supplied
2907         * recursive bits for other formats here.
2908         */
2909        if (options->output_format & (DIFF_FORMAT_PATCH |
2910                                      DIFF_FORMAT_NUMSTAT |
2911                                      DIFF_FORMAT_DIFFSTAT |
2912                                      DIFF_FORMAT_SHORTSTAT |
2913                                      DIFF_FORMAT_DIRSTAT |
2914                                      DIFF_FORMAT_SUMMARY |
2915                                      DIFF_FORMAT_CHECKDIFF))
2916                DIFF_OPT_SET(options, RECURSIVE);
2917        /*
2918         * Also pickaxe would not work very well if you do not say recursive
2919         */
2920        if (options->pickaxe)
2921                DIFF_OPT_SET(options, RECURSIVE);
2922        /*
2923         * When patches are generated, submodules diffed against the work tree
2924         * must be checked for dirtiness too so it can be shown in the output
2925         */
2926        if (options->output_format & DIFF_FORMAT_PATCH)
2927                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2928
2929        if (options->detect_rename && options->rename_limit < 0)
2930                options->rename_limit = diff_rename_limit_default;
2931        if (options->setup & DIFF_SETUP_USE_CACHE) {
2932                if (!active_cache)
2933                        /* read-cache does not die even when it fails
2934                         * so it is safe for us to do this here.  Also
2935                         * it does not smudge active_cache or active_nr
2936                         * when it fails, so we do not have to worry about
2937                         * cleaning it up ourselves either.
2938                         */
2939                        read_cache();
2940        }
2941        if (options->abbrev <= 0 || 40 < options->abbrev)
2942                options->abbrev = 40; /* full */
2943
2944        /*
2945         * It does not make sense to show the first hit we happened
2946         * to have found.  It does not make sense not to return with
2947         * exit code in such a case either.
2948         */
2949        if (DIFF_OPT_TST(options, QUICK)) {
2950                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2951                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2952        }
2953
2954        return 0;
2955}
2956
2957static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2958{
2959        char c, *eq;
2960        int len;
2961
2962        if (*arg != '-')
2963                return 0;
2964        c = *++arg;
2965        if (!c)
2966                return 0;
2967        if (c == arg_short) {
2968                c = *++arg;
2969                if (!c)
2970                        return 1;
2971                if (val && isdigit(c)) {
2972                        char *end;
2973                        int n = strtoul(arg, &end, 10);
2974                        if (*end)
2975                                return 0;
2976                        *val = n;
2977                        return 1;
2978                }
2979                return 0;
2980        }
2981        if (c != '-')
2982                return 0;
2983        arg++;
2984        eq = strchr(arg, '=');
2985        if (eq)
2986                len = eq - arg;
2987        else
2988                len = strlen(arg);
2989        if (!len || strncmp(arg, arg_long, len))
2990                return 0;
2991        if (eq) {
2992                int n;
2993                char *end;
2994                if (!isdigit(*++eq))
2995                        return 0;
2996                n = strtoul(eq, &end, 10);
2997                if (*end)
2998                        return 0;
2999                *val = n;
3000        }
3001        return 1;
3002}
3003
3004static int diff_scoreopt_parse(const char *opt);
3005
3006int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3007{
3008        const char *arg = av[0];
3009
3010        /* Output format options */
3011        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3012                options->output_format |= DIFF_FORMAT_PATCH;
3013        else if (opt_arg(arg, 'U', "unified", &options->context))
3014                options->output_format |= DIFF_FORMAT_PATCH;
3015        else if (!strcmp(arg, "--raw"))
3016                options->output_format |= DIFF_FORMAT_RAW;
3017        else if (!strcmp(arg, "--patch-with-raw"))
3018                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3019        else if (!strcmp(arg, "--numstat"))
3020                options->output_format |= DIFF_FORMAT_NUMSTAT;
3021        else if (!strcmp(arg, "--shortstat"))
3022                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3023        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3024                options->output_format |= DIFF_FORMAT_DIRSTAT;
3025        else if (!strcmp(arg, "--cumulative")) {
3026                options->output_format |= DIFF_FORMAT_DIRSTAT;
3027                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3028        } else if (opt_arg(arg, 0, "dirstat-by-file",
3029                           &options->dirstat_percent)) {
3030                options->output_format |= DIFF_FORMAT_DIRSTAT;
3031                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3032        }
3033        else if (!strcmp(arg, "--check"))
3034                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3035        else if (!strcmp(arg, "--summary"))
3036                options->output_format |= DIFF_FORMAT_SUMMARY;
3037        else if (!strcmp(arg, "--patch-with-stat"))
3038                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3039        else if (!strcmp(arg, "--name-only"))
3040                options->output_format |= DIFF_FORMAT_NAME;
3041        else if (!strcmp(arg, "--name-status"))
3042                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3043        else if (!strcmp(arg, "-s"))
3044                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3045        else if (!prefixcmp(arg, "--stat")) {
3046                char *end;
3047                int width = options->stat_width;
3048                int name_width = options->stat_name_width;
3049                arg += 6;
3050                end = (char *)arg;
3051
3052                switch (*arg) {
3053                case '-':
3054                        if (!prefixcmp(arg, "-width="))
3055                                width = strtoul(arg + 7, &end, 10);
3056                        else if (!prefixcmp(arg, "-name-width="))
3057                                name_width = strtoul(arg + 12, &end, 10);
3058                        break;
3059                case '=':
3060                        width = strtoul(arg+1, &end, 10);
3061                        if (*end == ',')
3062                                name_width = strtoul(end+1, &end, 10);
3063                }
3064
3065                /* Important! This checks all the error cases! */
3066                if (*end)
3067                        return 0;
3068                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3069                options->stat_name_width = name_width;
3070                options->stat_width = width;
3071        }
3072
3073        /* renames options */
3074        else if (!prefixcmp(arg, "-B")) {
3075                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3076                        return -1;
3077        }
3078        else if (!prefixcmp(arg, "-M")) {
3079                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3080                        return -1;
3081                options->detect_rename = DIFF_DETECT_RENAME;
3082        }
3083        else if (!prefixcmp(arg, "-C")) {
3084                if (options->detect_rename == DIFF_DETECT_COPY)
3085                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3086                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3087                        return -1;
3088                options->detect_rename = DIFF_DETECT_COPY;
3089        }
3090        else if (!strcmp(arg, "--no-renames"))
3091                options->detect_rename = 0;
3092        else if (!strcmp(arg, "--relative"))
3093                DIFF_OPT_SET(options, RELATIVE_NAME);
3094        else if (!prefixcmp(arg, "--relative=")) {
3095                DIFF_OPT_SET(options, RELATIVE_NAME);
3096                options->prefix = arg + 11;
3097        }
3098
3099        /* xdiff options */
3100        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3101                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3102        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3103                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3104        else if (!strcmp(arg, "--ignore-space-at-eol"))
3105                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3106        else if (!strcmp(arg, "--patience"))
3107                DIFF_XDL_SET(options, PATIENCE_DIFF);
3108
3109        /* flags options */
3110        else if (!strcmp(arg, "--binary")) {
3111                options->output_format |= DIFF_FORMAT_PATCH;
3112                DIFF_OPT_SET(options, BINARY);
3113        }
3114        else if (!strcmp(arg, "--full-index"))
3115                DIFF_OPT_SET(options, FULL_INDEX);
3116        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3117                DIFF_OPT_SET(options, TEXT);
3118        else if (!strcmp(arg, "-R"))
3119                DIFF_OPT_SET(options, REVERSE_DIFF);
3120        else if (!strcmp(arg, "--find-copies-harder"))
3121                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3122        else if (!strcmp(arg, "--follow"))
3123                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3124        else if (!strcmp(arg, "--color"))
3125                DIFF_OPT_SET(options, COLOR_DIFF);
3126        else if (!prefixcmp(arg, "--color=")) {
3127                int value = git_config_colorbool(NULL, arg+8, -1);
3128                if (value == 0)
3129                        DIFF_OPT_CLR(options, COLOR_DIFF);
3130                else if (value > 0)
3131                        DIFF_OPT_SET(options, COLOR_DIFF);
3132                else
3133                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3134        }
3135        else if (!strcmp(arg, "--no-color"))
3136                DIFF_OPT_CLR(options, COLOR_DIFF);
3137        else if (!strcmp(arg, "--color-words")) {
3138                DIFF_OPT_SET(options, COLOR_DIFF);
3139                options->word_diff = DIFF_WORDS_COLOR;
3140        }
3141        else if (!prefixcmp(arg, "--color-words=")) {
3142                DIFF_OPT_SET(options, COLOR_DIFF);
3143                options->word_diff = DIFF_WORDS_COLOR;
3144                options->word_regex = arg + 14;
3145        }
3146        else if (!strcmp(arg, "--word-diff")) {
3147                if (options->word_diff == DIFF_WORDS_NONE)
3148                        options->word_diff = DIFF_WORDS_PLAIN;
3149        }
3150        else if (!prefixcmp(arg, "--word-diff=")) {
3151                const char *type = arg + 12;
3152                if (!strcmp(type, "plain"))
3153                        options->word_diff = DIFF_WORDS_PLAIN;
3154                else if (!strcmp(type, "color")) {
3155                        DIFF_OPT_SET(options, COLOR_DIFF);
3156                        options->word_diff = DIFF_WORDS_COLOR;
3157                }
3158                else if (!strcmp(type, "porcelain"))
3159                        options->word_diff = DIFF_WORDS_PORCELAIN;
3160                else if (!strcmp(type, "none"))
3161                        options->word_diff = DIFF_WORDS_NONE;
3162                else
3163                        die("bad --word-diff argument: %s", type);
3164        }
3165        else if (!prefixcmp(arg, "--word-diff-regex=")) {
3166                if (options->word_diff == DIFF_WORDS_NONE)
3167                        options->word_diff = DIFF_WORDS_PLAIN;
3168                options->word_regex = arg + 18;
3169        }
3170        else if (!strcmp(arg, "--exit-code"))
3171                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3172        else if (!strcmp(arg, "--quiet"))
3173                DIFF_OPT_SET(options, QUICK);
3174        else if (!strcmp(arg, "--ext-diff"))
3175                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3176        else if (!strcmp(arg, "--no-ext-diff"))
3177                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3178        else if (!strcmp(arg, "--textconv"))
3179                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3180        else if (!strcmp(arg, "--no-textconv"))
3181                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3182        else if (!strcmp(arg, "--ignore-submodules"))
3183                handle_ignore_submodules_arg(options, "all");
3184        else if (!prefixcmp(arg, "--ignore-submodules="))
3185                handle_ignore_submodules_arg(options, arg + 20);
3186        else if (!strcmp(arg, "--submodule"))
3187                DIFF_OPT_SET(options, SUBMODULE_LOG);
3188        else if (!prefixcmp(arg, "--submodule=")) {
3189                if (!strcmp(arg + 12, "log"))
3190                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3191        }
3192
3193        /* misc options */
3194        else if (!strcmp(arg, "-z"))
3195                options->line_termination = 0;
3196        else if (!prefixcmp(arg, "-l"))
3197                options->rename_limit = strtoul(arg+2, NULL, 10);
3198        else if (!prefixcmp(arg, "-S"))
3199                options->pickaxe = arg + 2;
3200        else if (!strcmp(arg, "--pickaxe-all"))
3201                options->pickaxe_opts = DIFF_PICKAXE_ALL;
3202        else if (!strcmp(arg, "--pickaxe-regex"))
3203                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
3204        else if (!prefixcmp(arg, "-O"))
3205                options->orderfile = arg + 2;
3206        else if (!prefixcmp(arg, "--diff-filter="))
3207                options->filter = arg + 14;
3208        else if (!strcmp(arg, "--abbrev"))
3209                options->abbrev = DEFAULT_ABBREV;
3210        else if (!prefixcmp(arg, "--abbrev=")) {
3211                options->abbrev = strtoul(arg + 9, NULL, 10);
3212                if (options->abbrev < MINIMUM_ABBREV)
3213                        options->abbrev = MINIMUM_ABBREV;
3214                else if (40 < options->abbrev)
3215                        options->abbrev = 40;
3216        }
3217        else if (!prefixcmp(arg, "--src-prefix="))
3218                options->a_prefix = arg + 13;
3219        else if (!prefixcmp(arg, "--dst-prefix="))
3220                options->b_prefix = arg + 13;
3221        else if (!strcmp(arg, "--no-prefix"))
3222                options->a_prefix = options->b_prefix = "";
3223        else if (opt_arg(arg, '\0', "inter-hunk-context",
3224                         &options->interhunkcontext))
3225                ;
3226        else if (!prefixcmp(arg, "--output=")) {
3227                options->file = fopen(arg + strlen("--output="), "w");
3228                if (!options->file)
3229                        die_errno("Could not open '%s'", arg + strlen("--output="));
3230                options->close_file = 1;
3231        } else
3232                return 0;
3233        return 1;
3234}
3235
3236static int parse_num(const char **cp_p)
3237{
3238        unsigned long num, scale;
3239        int ch, dot;
3240        const char *cp = *cp_p;
3241
3242        num = 0;
3243        scale = 1;
3244        dot = 0;
3245        for (;;) {
3246                ch = *cp;
3247                if ( !dot && ch == '.' ) {
3248                        scale = 1;
3249                        dot = 1;
3250                } else if ( ch == '%' ) {
3251                        scale = dot ? scale*100 : 100;
3252                        cp++;   /* % is always at the end */
3253                        break;
3254                } else if ( ch >= '0' && ch <= '9' ) {
3255                        if ( scale < 100000 ) {
3256                                scale *= 10;
3257                                num = (num*10) + (ch-'0');
3258                        }
3259                } else {
3260                        break;
3261                }
3262                cp++;
3263        }
3264        *cp_p = cp;
3265
3266        /* user says num divided by scale and we say internally that
3267         * is MAX_SCORE * num / scale.
3268         */
3269        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3270}
3271
3272static int diff_scoreopt_parse(const char *opt)
3273{
3274        int opt1, opt2, cmd;
3275
3276        if (*opt++ != '-')
3277                return -1;
3278        cmd = *opt++;
3279        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3280                return -1; /* that is not a -M, -C nor -B option */
3281
3282        opt1 = parse_num(&opt);
3283        if (cmd != 'B')
3284                opt2 = 0;
3285        else {
3286                if (*opt == 0)
3287                        opt2 = 0;
3288                else if (*opt != '/')
3289                        return -1; /* we expect -B80/99 or -B80 */
3290                else {
3291                        opt++;
3292                        opt2 = parse_num(&opt);
3293                }
3294        }
3295        if (*opt != 0)
3296                return -1;
3297        return opt1 | (opt2 << 16);
3298}
3299
3300struct diff_queue_struct diff_queued_diff;
3301
3302void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3303{
3304        if (queue->alloc <= queue->nr) {
3305                queue->alloc = alloc_nr(queue->alloc);
3306                queue->queue = xrealloc(queue->queue,
3307                                        sizeof(dp) * queue->alloc);
3308        }
3309        queue->queue[queue->nr++] = dp;
3310}
3311
3312struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3313                                 struct diff_filespec *one,
3314                                 struct diff_filespec *two)
3315{
3316        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3317        dp->one = one;
3318        dp->two = two;
3319        if (queue)
3320                diff_q(queue, dp);
3321        return dp;
3322}
3323
3324void diff_free_filepair(struct diff_filepair *p)
3325{
3326        free_filespec(p->one);
3327        free_filespec(p->two);
3328        free(p);
3329}
3330
3331/* This is different from find_unique_abbrev() in that
3332 * it stuffs the result with dots for alignment.
3333 */
3334const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3335{
3336        int abblen;
3337        const char *abbrev;
3338        if (len == 40)
3339                return sha1_to_hex(sha1);
3340
3341        abbrev = find_unique_abbrev(sha1, len);
3342        abblen = strlen(abbrev);
3343        if (abblen < 37) {
3344                static char hex[41];
3345                if (len < abblen && abblen <= len + 2)
3346                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3347                else
3348                        sprintf(hex, "%s...", abbrev);
3349                return hex;
3350        }
3351        return sha1_to_hex(sha1);
3352}
3353
3354static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3355{
3356        int line_termination = opt->line_termination;
3357        int inter_name_termination = line_termination ? '\t' : '\0';
3358        if (opt->output_prefix) {
3359                struct strbuf *msg = NULL;
3360                msg = opt->output_prefix(opt, opt->output_prefix_data);
3361                fprintf(opt->file, "%s", msg->buf);
3362        }
3363
3364        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3365                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3366                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3367                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3368        }
3369        if (p->score) {
3370                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3371                        inter_name_termination);
3372        } else {
3373                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3374        }
3375
3376        if (p->status == DIFF_STATUS_COPIED ||
3377            p->status == DIFF_STATUS_RENAMED) {
3378                const char *name_a, *name_b;
3379                name_a = p->one->path;
3380                name_b = p->two->path;
3381                strip_prefix(opt->prefix_length, &name_a, &name_b);
3382                write_name_quoted(name_a, opt->file, inter_name_termination);
3383                write_name_quoted(name_b, opt->file, line_termination);
3384        } else {
3385                const char *name_a, *name_b;
3386                name_a = p->one->mode ? p->one->path : p->two->path;
3387                name_b = NULL;
3388                strip_prefix(opt->prefix_length, &name_a, &name_b);
3389                write_name_quoted(name_a, opt->file, line_termination);
3390        }
3391}
3392
3393int diff_unmodified_pair(struct diff_filepair *p)
3394{
3395        /* This function is written stricter than necessary to support
3396         * the currently implemented transformers, but the idea is to
3397         * let transformers to produce diff_filepairs any way they want,
3398         * and filter and clean them up here before producing the output.
3399         */
3400        struct diff_filespec *one = p->one, *two = p->two;
3401
3402        if (DIFF_PAIR_UNMERGED(p))
3403                return 0; /* unmerged is interesting */
3404
3405        /* deletion, addition, mode or type change
3406         * and rename are all interesting.
3407         */
3408        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3409            DIFF_PAIR_MODE_CHANGED(p) ||
3410            strcmp(one->path, two->path))
3411                return 0;
3412
3413        /* both are valid and point at the same path.  that is, we are
3414         * dealing with a change.
3415         */
3416        if (one->sha1_valid && two->sha1_valid &&
3417            !hashcmp(one->sha1, two->sha1) &&
3418            !one->dirty_submodule && !two->dirty_submodule)
3419                return 1; /* no change */
3420        if (!one->sha1_valid && !two->sha1_valid)
3421                return 1; /* both look at the same file on the filesystem. */
3422        return 0;
3423}
3424
3425static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3426{
3427        if (diff_unmodified_pair(p))
3428                return;
3429
3430        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3431            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3432                return; /* no tree diffs in patch format */
3433
3434        run_diff(p, o);
3435}
3436
3437static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3438                            struct diffstat_t *diffstat)
3439{
3440        if (diff_unmodified_pair(p))
3441                return;
3442
3443        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3444            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3445                return; /* no tree diffs in patch format */
3446
3447        run_diffstat(p, o, diffstat);
3448}
3449
3450static void diff_flush_checkdiff(struct diff_filepair *p,
3451                struct diff_options *o)
3452{
3453        if (diff_unmodified_pair(p))
3454                return;
3455
3456        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3457            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3458                return; /* no tree diffs in patch format */
3459
3460        run_checkdiff(p, o);
3461}
3462
3463int diff_queue_is_empty(void)
3464{
3465        struct diff_queue_struct *q = &diff_queued_diff;
3466        int i;
3467        for (i = 0; i < q->nr; i++)
3468                if (!diff_unmodified_pair(q->queue[i]))
3469                        return 0;
3470        return 1;
3471}
3472
3473#if DIFF_DEBUG
3474void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3475{
3476        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3477                x, one ? one : "",
3478                s->path,
3479                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3480                s->mode,
3481                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3482        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3483                x, one ? one : "",
3484                s->size, s->xfrm_flags);
3485}
3486
3487void diff_debug_filepair(const struct diff_filepair *p, int i)
3488{
3489        diff_debug_filespec(p->one, i, "one");
3490        diff_debug_filespec(p->two, i, "two");
3491        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3492                p->score, p->status ? p->status : '?',
3493                p->one->rename_used, p->broken_pair);
3494}
3495
3496void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3497{
3498        int i;
3499        if (msg)
3500                fprintf(stderr, "%s\n", msg);
3501        fprintf(stderr, "q->nr = %d\n", q->nr);
3502        for (i = 0; i < q->nr; i++) {
3503                struct diff_filepair *p = q->queue[i];
3504                diff_debug_filepair(p, i);
3505        }
3506}
3507#endif
3508
3509static void diff_resolve_rename_copy(void)
3510{
3511        int i;
3512        struct diff_filepair *p;
3513        struct diff_queue_struct *q = &diff_queued_diff;
3514
3515        diff_debug_queue("resolve-rename-copy", q);
3516
3517        for (i = 0; i < q->nr; i++) {
3518                p = q->queue[i];
3519                p->status = 0; /* undecided */
3520                if (DIFF_PAIR_UNMERGED(p))
3521                        p->status = DIFF_STATUS_UNMERGED;
3522                else if (!DIFF_FILE_VALID(p->one))
3523                        p->status = DIFF_STATUS_ADDED;
3524                else if (!DIFF_FILE_VALID(p->two))
3525                        p->status = DIFF_STATUS_DELETED;
3526                else if (DIFF_PAIR_TYPE_CHANGED(p))
3527                        p->status = DIFF_STATUS_TYPE_CHANGED;
3528
3529                /* from this point on, we are dealing with a pair
3530                 * whose both sides are valid and of the same type, i.e.
3531                 * either in-place edit or rename/copy edit.
3532                 */
3533                else if (DIFF_PAIR_RENAME(p)) {
3534                        /*
3535                         * A rename might have re-connected a broken
3536                         * pair up, causing the pathnames to be the
3537                         * same again. If so, that's not a rename at
3538                         * all, just a modification..
3539                         *
3540                         * Otherwise, see if this source was used for
3541                         * multiple renames, in which case we decrement
3542                         * the count, and call it a copy.
3543                         */
3544                        if (!strcmp(p->one->path, p->two->path))
3545                                p->status = DIFF_STATUS_MODIFIED;
3546                        else if (--p->one->rename_used > 0)
3547                                p->status = DIFF_STATUS_COPIED;
3548                        else
3549                                p->status = DIFF_STATUS_RENAMED;
3550                }
3551                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3552                         p->one->mode != p->two->mode ||
3553                         p->one->dirty_submodule ||
3554                         p->two->dirty_submodule ||
3555                         is_null_sha1(p->one->sha1))
3556                        p->status = DIFF_STATUS_MODIFIED;
3557                else {
3558                        /* This is a "no-change" entry and should not
3559                         * happen anymore, but prepare for broken callers.
3560                         */
3561                        error("feeding unmodified %s to diffcore",
3562                              p->one->path);
3563                        p->status = DIFF_STATUS_UNKNOWN;
3564                }
3565        }
3566        diff_debug_queue("resolve-rename-copy done", q);
3567}
3568
3569static int check_pair_status(struct diff_filepair *p)
3570{
3571        switch (p->status) {
3572        case DIFF_STATUS_UNKNOWN:
3573                return 0;
3574        case 0:
3575                die("internal error in diff-resolve-rename-copy");
3576        default:
3577                return 1;
3578        }
3579}
3580
3581static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3582{
3583        int fmt = opt->output_format;
3584
3585        if (fmt & DIFF_FORMAT_CHECKDIFF)
3586                diff_flush_checkdiff(p, opt);
3587        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3588                diff_flush_raw(p, opt);
3589        else if (fmt & DIFF_FORMAT_NAME) {
3590                const char *name_a, *name_b;
3591                name_a = p->two->path;
3592                name_b = NULL;
3593                strip_prefix(opt->prefix_length, &name_a, &name_b);
3594                write_name_quoted(name_a, opt->file, opt->line_termination);
3595        }
3596}
3597
3598static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3599{
3600        if (fs->mode)
3601                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3602        else
3603                fprintf(file, " %s ", newdelete);
3604        write_name_quoted(fs->path, file, '\n');
3605}
3606
3607
3608static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3609                const char *line_prefix)
3610{
3611        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3612                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3613                        p->two->mode, show_name ? ' ' : '\n');
3614                if (show_name) {
3615                        write_name_quoted(p->two->path, file, '\n');
3616                }
3617        }
3618}
3619
3620static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3621                        const char *line_prefix)
3622{
3623        char *names = pprint_rename(p->one->path, p->two->path);
3624
3625        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3626        free(names);
3627        show_mode_change(file, p, 0, line_prefix);
3628}
3629
3630static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3631{
3632        FILE *file = opt->file;
3633        char *line_prefix = "";
3634
3635        if (opt->output_prefix) {
3636                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3637                line_prefix = buf->buf;
3638        }
3639
3640        switch(p->status) {
3641        case DIFF_STATUS_DELETED:
3642                fputs(line_prefix, file);
3643                show_file_mode_name(file, "delete", p->one);
3644                break;
3645        case DIFF_STATUS_ADDED:
3646                fputs(line_prefix, file);
3647                show_file_mode_name(file, "create", p->two);
3648                break;
3649        case DIFF_STATUS_COPIED:
3650                fputs(line_prefix, file);
3651                show_rename_copy(file, "copy", p, line_prefix);
3652                break;
3653        case DIFF_STATUS_RENAMED:
3654                fputs(line_prefix, file);
3655                show_rename_copy(file, "rename", p, line_prefix);
3656                break;
3657        default:
3658                if (p->score) {
3659                        fprintf(file, "%s rewrite ", line_prefix);
3660                        write_name_quoted(p->two->path, file, ' ');
3661                        fprintf(file, "(%d%%)\n", similarity_index(p));
3662                }
3663                show_mode_change(file, p, !p->score, line_prefix);
3664                break;
3665        }
3666}
3667
3668struct patch_id_t {
3669        git_SHA_CTX *ctx;
3670        int patchlen;
3671};
3672
3673static int remove_space(char *line, int len)
3674{
3675        int i;
3676        char *dst = line;
3677        unsigned char c;
3678
3679        for (i = 0; i < len; i++)
3680                if (!isspace((c = line[i])))
3681                        *dst++ = c;
3682
3683        return dst - line;
3684}
3685
3686static void patch_id_consume(void *priv, char *line, unsigned long len)
3687{
3688        struct patch_id_t *data = priv;
3689        int new_len;
3690
3691        /* Ignore line numbers when computing the SHA1 of the patch */
3692        if (!prefixcmp(line, "@@ -"))
3693                return;
3694
3695        new_len = remove_space(line, len);
3696
3697        git_SHA1_Update(data->ctx, line, new_len);
3698        data->patchlen += new_len;
3699}
3700
3701/* returns 0 upon success, and writes result into sha1 */
3702static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3703{
3704        struct diff_queue_struct *q = &diff_queued_diff;
3705        int i;
3706        git_SHA_CTX ctx;
3707        struct patch_id_t data;
3708        char buffer[PATH_MAX * 4 + 20];
3709
3710        git_SHA1_Init(&ctx);
3711        memset(&data, 0, sizeof(struct patch_id_t));
3712        data.ctx = &ctx;
3713
3714        for (i = 0; i < q->nr; i++) {
3715                xpparam_t xpp;
3716                xdemitconf_t xecfg;
3717                mmfile_t mf1, mf2;
3718                struct diff_filepair *p = q->queue[i];
3719                int len1, len2;
3720
3721                memset(&xpp, 0, sizeof(xpp));
3722                memset(&xecfg, 0, sizeof(xecfg));
3723                if (p->status == 0)
3724                        return error("internal diff status error");
3725                if (p->status == DIFF_STATUS_UNKNOWN)
3726                        continue;
3727                if (diff_unmodified_pair(p))
3728                        continue;
3729                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3730                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3731                        continue;
3732                if (DIFF_PAIR_UNMERGED(p))
3733                        continue;
3734
3735                diff_fill_sha1_info(p->one);
3736                diff_fill_sha1_info(p->two);
3737                if (fill_mmfile(&mf1, p->one) < 0 ||
3738                                fill_mmfile(&mf2, p->two) < 0)
3739                        return error("unable to read files to diff");
3740
3741                len1 = remove_space(p->one->path, strlen(p->one->path));
3742                len2 = remove_space(p->two->path, strlen(p->two->path));
3743                if (p->one->mode == 0)
3744                        len1 = snprintf(buffer, sizeof(buffer),
3745                                        "diff--gita/%.*sb/%.*s"
3746                                        "newfilemode%06o"
3747                                        "---/dev/null"
3748                                        "+++b/%.*s",
3749                                        len1, p->one->path,
3750                                        len2, p->two->path,
3751                                        p->two->mode,
3752                                        len2, p->two->path);
3753                else if (p->two->mode == 0)
3754                        len1 = snprintf(buffer, sizeof(buffer),
3755                                        "diff--gita/%.*sb/%.*s"
3756                                        "deletedfilemode%06o"
3757                                        "---a/%.*s"
3758                                        "+++/dev/null",
3759                                        len1, p->one->path,
3760                                        len2, p->two->path,
3761                                        p->one->mode,
3762                                        len1, p->one->path);
3763                else
3764                        len1 = snprintf(buffer, sizeof(buffer),
3765                                        "diff--gita/%.*sb/%.*s"
3766                                        "---a/%.*s"
3767                                        "+++b/%.*s",
3768                                        len1, p->one->path,
3769                                        len2, p->two->path,
3770                                        len1, p->one->path,
3771                                        len2, p->two->path);
3772                git_SHA1_Update(&ctx, buffer, len1);
3773
3774                xpp.flags = 0;
3775                xecfg.ctxlen = 3;
3776                xecfg.flags = XDL_EMIT_FUNCNAMES;
3777                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3778                              &xpp, &xecfg);
3779        }
3780
3781        git_SHA1_Final(sha1, &ctx);
3782        return 0;
3783}
3784
3785int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3786{
3787        struct diff_queue_struct *q = &diff_queued_diff;
3788        int i;
3789        int result = diff_get_patch_id(options, sha1);
3790
3791        for (i = 0; i < q->nr; i++)
3792                diff_free_filepair(q->queue[i]);
3793
3794        free(q->queue);
3795        DIFF_QUEUE_CLEAR(q);
3796
3797        return result;
3798}
3799
3800static int is_summary_empty(const struct diff_queue_struct *q)
3801{
3802        int i;
3803
3804        for (i = 0; i < q->nr; i++) {
3805                const struct diff_filepair *p = q->queue[i];
3806
3807                switch (p->status) {
3808                case DIFF_STATUS_DELETED:
3809                case DIFF_STATUS_ADDED:
3810                case DIFF_STATUS_COPIED:
3811                case DIFF_STATUS_RENAMED:
3812                        return 0;
3813                default:
3814                        if (p->score)
3815                                return 0;
3816                        if (p->one->mode && p->two->mode &&
3817                            p->one->mode != p->two->mode)
3818                                return 0;
3819                        break;
3820                }
3821        }
3822        return 1;
3823}
3824
3825void diff_flush(struct diff_options *options)
3826{
3827        struct diff_queue_struct *q = &diff_queued_diff;
3828        int i, output_format = options->output_format;
3829        int separator = 0;
3830
3831        /*
3832         * Order: raw, stat, summary, patch
3833         * or:    name/name-status/checkdiff (other bits clear)
3834         */
3835        if (!q->nr)
3836                goto free_queue;
3837
3838        if (output_format & (DIFF_FORMAT_RAW |
3839                             DIFF_FORMAT_NAME |
3840                             DIFF_FORMAT_NAME_STATUS |
3841                             DIFF_FORMAT_CHECKDIFF)) {
3842                for (i = 0; i < q->nr; i++) {
3843                        struct diff_filepair *p = q->queue[i];
3844                        if (check_pair_status(p))
3845                                flush_one_pair(p, options);
3846                }
3847                separator++;
3848        }
3849
3850        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3851                struct diffstat_t diffstat;
3852
3853                memset(&diffstat, 0, sizeof(struct diffstat_t));
3854                for (i = 0; i < q->nr; i++) {
3855                        struct diff_filepair *p = q->queue[i];
3856                        if (check_pair_status(p))
3857                                diff_flush_stat(p, options, &diffstat);
3858                }
3859                if (output_format & DIFF_FORMAT_NUMSTAT)
3860                        show_numstat(&diffstat, options);
3861                if (output_format & DIFF_FORMAT_DIFFSTAT)
3862                        show_stats(&diffstat, options);
3863                if (output_format & DIFF_FORMAT_SHORTSTAT)
3864                        show_shortstats(&diffstat, options);
3865                free_diffstat_info(&diffstat);
3866                separator++;
3867        }
3868        if (output_format & DIFF_FORMAT_DIRSTAT)
3869                show_dirstat(options);
3870
3871        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3872                for (i = 0; i < q->nr; i++) {
3873                        diff_summary(options, q->queue[i]);
3874                }
3875                separator++;
3876        }
3877
3878        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3879            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3880            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3881                /*
3882                 * run diff_flush_patch for the exit status. setting
3883                 * options->file to /dev/null should be safe, becaue we
3884                 * aren't supposed to produce any output anyway.
3885                 */
3886                if (options->close_file)
3887                        fclose(options->file);
3888                options->file = fopen("/dev/null", "w");
3889                if (!options->file)
3890                        die_errno("Could not open /dev/null");
3891                options->close_file = 1;
3892                for (i = 0; i < q->nr; i++) {
3893                        struct diff_filepair *p = q->queue[i];
3894                        if (check_pair_status(p))
3895                                diff_flush_patch(p, options);
3896                        if (options->found_changes)
3897                                break;
3898                }
3899        }
3900
3901        if (output_format & DIFF_FORMAT_PATCH) {
3902                if (separator) {
3903                        putc(options->line_termination, options->file);
3904                        if (options->stat_sep) {
3905                                /* attach patch instead of inline */
3906                                fputs(options->stat_sep, options->file);
3907                        }
3908                }
3909
3910                for (i = 0; i < q->nr; i++) {
3911                        struct diff_filepair *p = q->queue[i];
3912                        if (check_pair_status(p))
3913                                diff_flush_patch(p, options);
3914                }
3915        }
3916
3917        if (output_format & DIFF_FORMAT_CALLBACK)
3918                options->format_callback(q, options, options->format_callback_data);
3919
3920        for (i = 0; i < q->nr; i++)
3921                diff_free_filepair(q->queue[i]);
3922free_queue:
3923        free(q->queue);
3924        DIFF_QUEUE_CLEAR(q);
3925        if (options->close_file)
3926                fclose(options->file);
3927
3928        /*
3929         * Report the content-level differences with HAS_CHANGES;
3930         * diff_addremove/diff_change does not set the bit when
3931         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3932         */
3933        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3934                if (options->found_changes)
3935                        DIFF_OPT_SET(options, HAS_CHANGES);
3936                else
3937                        DIFF_OPT_CLR(options, HAS_CHANGES);
3938        }
3939}
3940
3941static void diffcore_apply_filter(const char *filter)
3942{
3943        int i;
3944        struct diff_queue_struct *q = &diff_queued_diff;
3945        struct diff_queue_struct outq;
3946        DIFF_QUEUE_CLEAR(&outq);
3947
3948        if (!filter)
3949                return;
3950
3951        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3952                int found;
3953                for (i = found = 0; !found && i < q->nr; i++) {
3954                        struct diff_filepair *p = q->queue[i];
3955                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3956                             ((p->score &&
3957                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3958                              (!p->score &&
3959                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3960                            ((p->status != DIFF_STATUS_MODIFIED) &&
3961                             strchr(filter, p->status)))
3962                                found++;
3963                }
3964                if (found)
3965                        return;
3966
3967                /* otherwise we will clear the whole queue
3968                 * by copying the empty outq at the end of this
3969                 * function, but first clear the current entries
3970                 * in the queue.
3971                 */
3972                for (i = 0; i < q->nr; i++)
3973                        diff_free_filepair(q->queue[i]);
3974        }
3975        else {
3976                /* Only the matching ones */
3977                for (i = 0; i < q->nr; i++) {
3978                        struct diff_filepair *p = q->queue[i];
3979
3980                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3981                             ((p->score &&
3982                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3983                              (!p->score &&
3984                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3985                            ((p->status != DIFF_STATUS_MODIFIED) &&
3986                             strchr(filter, p->status)))
3987                                diff_q(&outq, p);
3988                        else
3989                                diff_free_filepair(p);
3990                }
3991        }
3992        free(q->queue);
3993        *q = outq;
3994}
3995
3996/* Check whether two filespecs with the same mode and size are identical */
3997static int diff_filespec_is_identical(struct diff_filespec *one,
3998                                      struct diff_filespec *two)
3999{
4000        if (S_ISGITLINK(one->mode))
4001                return 0;
4002        if (diff_populate_filespec(one, 0))
4003                return 0;
4004        if (diff_populate_filespec(two, 0))
4005                return 0;
4006        return !memcmp(one->data, two->data, one->size);
4007}
4008
4009static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4010{
4011        int i;
4012        struct diff_queue_struct *q = &diff_queued_diff;
4013        struct diff_queue_struct outq;
4014        DIFF_QUEUE_CLEAR(&outq);
4015
4016        for (i = 0; i < q->nr; i++) {
4017                struct diff_filepair *p = q->queue[i];
4018
4019                /*
4020                 * 1. Entries that come from stat info dirtiness
4021                 *    always have both sides (iow, not create/delete),
4022                 *    one side of the object name is unknown, with
4023                 *    the same mode and size.  Keep the ones that
4024                 *    do not match these criteria.  They have real
4025                 *    differences.
4026                 *
4027                 * 2. At this point, the file is known to be modified,
4028                 *    with the same mode and size, and the object
4029                 *    name of one side is unknown.  Need to inspect
4030                 *    the identical contents.
4031                 */
4032                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4033                    !DIFF_FILE_VALID(p->two) ||
4034                    (p->one->sha1_valid && p->two->sha1_valid) ||
4035                    (p->one->mode != p->two->mode) ||
4036                    diff_populate_filespec(p->one, 1) ||
4037                    diff_populate_filespec(p->two, 1) ||
4038                    (p->one->size != p->two->size) ||
4039                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4040                        diff_q(&outq, p);
4041                else {
4042                        /*
4043                         * The caller can subtract 1 from skip_stat_unmatch
4044                         * to determine how many paths were dirty only
4045                         * due to stat info mismatch.
4046                         */
4047                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4048                                diffopt->skip_stat_unmatch++;
4049                        diff_free_filepair(p);
4050                }
4051        }
4052        free(q->queue);
4053        *q = outq;
4054}
4055
4056static int diffnamecmp(const void *a_, const void *b_)
4057{
4058        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4059        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4060        const char *name_a, *name_b;
4061
4062        name_a = a->one ? a->one->path : a->two->path;
4063        name_b = b->one ? b->one->path : b->two->path;
4064        return strcmp(name_a, name_b);
4065}
4066
4067void diffcore_fix_diff_index(struct diff_options *options)
4068{
4069        struct diff_queue_struct *q = &diff_queued_diff;
4070        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4071}
4072
4073void diffcore_std(struct diff_options *options)
4074{
4075        if (options->skip_stat_unmatch)
4076                diffcore_skip_stat_unmatch(options);
4077        if (!options->found_follow) {
4078                /* See try_to_follow_renames() in tree-diff.c */
4079                if (options->break_opt != -1)
4080                        diffcore_break(options->break_opt);
4081                if (options->detect_rename)
4082                        diffcore_rename(options);
4083                if (options->break_opt != -1)
4084                        diffcore_merge_broken();
4085        }
4086        if (options->pickaxe)
4087                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
4088        if (options->orderfile)
4089                diffcore_order(options->orderfile);
4090        if (!options->found_follow)
4091                /* See try_to_follow_renames() in tree-diff.c */
4092                diff_resolve_rename_copy();
4093        diffcore_apply_filter(options->filter);
4094
4095        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4096                DIFF_OPT_SET(options, HAS_CHANGES);
4097        else
4098                DIFF_OPT_CLR(options, HAS_CHANGES);
4099
4100        options->found_follow = 0;
4101}
4102
4103int diff_result_code(struct diff_options *opt, int status)
4104{
4105        int result = 0;
4106        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4107            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4108                return status;
4109        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4110            DIFF_OPT_TST(opt, HAS_CHANGES))
4111                result |= 01;
4112        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4113            DIFF_OPT_TST(opt, CHECK_FAILED))
4114                result |= 02;
4115        return result;
4116}
4117
4118void diff_addremove(struct diff_options *options,
4119                    int addremove, unsigned mode,
4120                    const unsigned char *sha1,
4121                    const char *concatpath, unsigned dirty_submodule)
4122{
4123        struct diff_filespec *one, *two;
4124
4125        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
4126                return;
4127
4128        /* This may look odd, but it is a preparation for
4129         * feeding "there are unchanged files which should
4130         * not produce diffs, but when you are doing copy
4131         * detection you would need them, so here they are"
4132         * entries to the diff-core.  They will be prefixed
4133         * with something like '=' or '*' (I haven't decided
4134         * which but should not make any difference).
4135         * Feeding the same new and old to diff_change()
4136         * also has the same effect.
4137         * Before the final output happens, they are pruned after
4138         * merged into rename/copy pairs as appropriate.
4139         */
4140        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4141                addremove = (addremove == '+' ? '-' :
4142                             addremove == '-' ? '+' : addremove);
4143
4144        if (options->prefix &&
4145            strncmp(concatpath, options->prefix, options->prefix_length))
4146                return;
4147
4148        one = alloc_filespec(concatpath);
4149        two = alloc_filespec(concatpath);
4150
4151        if (addremove != '+')
4152                fill_filespec(one, sha1, mode);
4153        if (addremove != '-') {
4154                fill_filespec(two, sha1, mode);
4155                two->dirty_submodule = dirty_submodule;
4156        }
4157
4158        diff_queue(&diff_queued_diff, one, two);
4159        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4160                DIFF_OPT_SET(options, HAS_CHANGES);
4161}
4162
4163void diff_change(struct diff_options *options,
4164                 unsigned old_mode, unsigned new_mode,
4165                 const unsigned char *old_sha1,
4166                 const unsigned char *new_sha1,
4167                 const char *concatpath,
4168                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4169{
4170        struct diff_filespec *one, *two;
4171
4172        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
4173                        && S_ISGITLINK(new_mode))
4174                return;
4175
4176        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4177                unsigned tmp;
4178                const unsigned char *tmp_c;
4179                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4180                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4181                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4182                        new_dirty_submodule = tmp;
4183        }
4184
4185        if (options->prefix &&
4186            strncmp(concatpath, options->prefix, options->prefix_length))
4187                return;
4188
4189        one = alloc_filespec(concatpath);
4190        two = alloc_filespec(concatpath);
4191        fill_filespec(one, old_sha1, old_mode);
4192        fill_filespec(two, new_sha1, new_mode);
4193        one->dirty_submodule = old_dirty_submodule;
4194        two->dirty_submodule = new_dirty_submodule;
4195
4196        diff_queue(&diff_queued_diff, one, two);
4197        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4198                DIFF_OPT_SET(options, HAS_CHANGES);
4199}
4200
4201void diff_unmerge(struct diff_options *options,
4202                  const char *path,
4203                  unsigned mode, const unsigned char *sha1)
4204{
4205        struct diff_filespec *one, *two;
4206
4207        if (options->prefix &&
4208            strncmp(path, options->prefix, options->prefix_length))
4209                return;
4210
4211        one = alloc_filespec(path);
4212        two = alloc_filespec(path);
4213        fill_filespec(one, sha1, mode);
4214        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4215}
4216
4217static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4218                size_t *outsize)
4219{
4220        struct diff_tempfile *temp;
4221        const char *argv[3];
4222        const char **arg = argv;
4223        struct child_process child;
4224        struct strbuf buf = STRBUF_INIT;
4225        int err = 0;
4226
4227        temp = prepare_temp_file(spec->path, spec);
4228        *arg++ = pgm;
4229        *arg++ = temp->name;
4230        *arg = NULL;
4231
4232        memset(&child, 0, sizeof(child));
4233        child.use_shell = 1;
4234        child.argv = argv;
4235        child.out = -1;
4236        if (start_command(&child)) {
4237                remove_tempfile();
4238                return NULL;
4239        }
4240
4241        if (strbuf_read(&buf, child.out, 0) < 0)
4242                err = error("error reading from textconv command '%s'", pgm);
4243        close(child.out);
4244
4245        if (finish_command(&child) || err) {
4246                strbuf_release(&buf);
4247                remove_tempfile();
4248                return NULL;
4249        }
4250        remove_tempfile();
4251
4252        return strbuf_detach(&buf, outsize);
4253}
4254
4255size_t fill_textconv(struct userdiff_driver *driver,
4256                     struct diff_filespec *df,
4257                     char **outbuf)
4258{
4259        size_t size;
4260
4261        if (!driver || !driver->textconv) {
4262                if (!DIFF_FILE_VALID(df)) {
4263                        *outbuf = "";
4264                        return 0;
4265                }
4266                if (diff_populate_filespec(df, 0))
4267                        die("unable to read files to diff");
4268                *outbuf = df->data;
4269                return df->size;
4270        }
4271
4272        if (driver->textconv_cache) {
4273                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4274                                          &size);
4275                if (*outbuf)
4276                        return size;
4277        }
4278
4279        *outbuf = run_textconv(driver->textconv, df, &size);
4280        if (!*outbuf)
4281                die("unable to read files to diff");
4282
4283        if (driver->textconv_cache) {
4284                /* ignore errors, as we might be in a readonly repository */
4285                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4286                                size);
4287                /*
4288                 * we could save up changes and flush them all at the end,
4289                 * but we would need an extra call after all diffing is done.
4290                 * Since generating a cache entry is the slow path anyway,
4291                 * this extra overhead probably isn't a big deal.
4292                 */
4293                notes_cache_write(driver->textconv_cache);
4294        }
4295
4296        return size;
4297}