diff.con commit t3404: fix a grammo (commands are ran -> commands are run) (fa90ab4)
   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                free(ecbdata->diff_words->word_regex);
 916                free(ecbdata->diff_words);
 917                ecbdata->diff_words = NULL;
 918        }
 919}
 920
 921const char *diff_get_color(int diff_use_color, enum color_diff ix)
 922{
 923        if (diff_use_color)
 924                return diff_colors[ix];
 925        return "";
 926}
 927
 928static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 929{
 930        const char *cp;
 931        unsigned long allot;
 932        size_t l = len;
 933
 934        if (ecb->truncate)
 935                return ecb->truncate(line, len);
 936        cp = line;
 937        allot = l;
 938        while (0 < l) {
 939                (void) utf8_width(&cp, &l);
 940                if (!cp)
 941                        break; /* truncated in the middle? */
 942        }
 943        return allot - l;
 944}
 945
 946static void find_lno(const char *line, struct emit_callback *ecbdata)
 947{
 948        const char *p;
 949        ecbdata->lno_in_preimage = 0;
 950        ecbdata->lno_in_postimage = 0;
 951        p = strchr(line, '-');
 952        if (!p)
 953                return; /* cannot happen */
 954        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 955        p = strchr(p, '+');
 956        if (!p)
 957                return; /* cannot happen */
 958        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 959}
 960
 961static void fn_out_consume(void *priv, char *line, unsigned long len)
 962{
 963        struct emit_callback *ecbdata = priv;
 964        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 965        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 966        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 967        struct diff_options *o = ecbdata->opt;
 968        char *line_prefix = "";
 969        struct strbuf *msgbuf;
 970
 971        if (o && o->output_prefix) {
 972                msgbuf = o->output_prefix(o, o->output_prefix_data);
 973                line_prefix = msgbuf->buf;
 974        }
 975
 976        if (ecbdata->header) {
 977                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 978                strbuf_reset(ecbdata->header);
 979                ecbdata->header = NULL;
 980        }
 981        *(ecbdata->found_changesp) = 1;
 982
 983        if (ecbdata->label_path[0]) {
 984                const char *name_a_tab, *name_b_tab;
 985
 986                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 987                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 988
 989                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
 990                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
 991                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
 992                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
 993                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 994        }
 995
 996        if (diff_suppress_blank_empty
 997            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 998                line[0] = '\n';
 999                len = 1;
1000        }
1001
1002        if (line[0] == '@') {
1003                if (ecbdata->diff_words)
1004                        diff_words_flush(ecbdata);
1005                len = sane_truncate_line(ecbdata, line, len);
1006                find_lno(line, ecbdata);
1007                emit_hunk_header(ecbdata, line, len);
1008                if (line[len-1] != '\n')
1009                        putc('\n', ecbdata->opt->file);
1010                return;
1011        }
1012
1013        if (len < 1) {
1014                emit_line(ecbdata->opt, reset, reset, line, len);
1015                if (ecbdata->diff_words
1016                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1017                        fputs("~\n", ecbdata->opt->file);
1018                return;
1019        }
1020
1021        if (ecbdata->diff_words) {
1022                if (line[0] == '-') {
1023                        diff_words_append(line, len,
1024                                          &ecbdata->diff_words->minus);
1025                        return;
1026                } else if (line[0] == '+') {
1027                        diff_words_append(line, len,
1028                                          &ecbdata->diff_words->plus);
1029                        return;
1030                }
1031                diff_words_flush(ecbdata);
1032                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1033                        emit_line(ecbdata->opt, plain, reset, line, len);
1034                        fputs("~\n", ecbdata->opt->file);
1035                } else {
1036                        /* don't print the prefix character */
1037                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1038                }
1039                return;
1040        }
1041
1042        if (line[0] != '+') {
1043                const char *color =
1044                        diff_get_color(ecbdata->color_diff,
1045                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1046                ecbdata->lno_in_preimage++;
1047                if (line[0] == ' ')
1048                        ecbdata->lno_in_postimage++;
1049                emit_line(ecbdata->opt, color, reset, line, len);
1050        } else {
1051                ecbdata->lno_in_postimage++;
1052                emit_add_line(reset, ecbdata, line + 1, len - 1);
1053        }
1054}
1055
1056static char *pprint_rename(const char *a, const char *b)
1057{
1058        const char *old = a;
1059        const char *new = b;
1060        struct strbuf name = STRBUF_INIT;
1061        int pfx_length, sfx_length;
1062        int len_a = strlen(a);
1063        int len_b = strlen(b);
1064        int a_midlen, b_midlen;
1065        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1066        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1067
1068        if (qlen_a || qlen_b) {
1069                quote_c_style(a, &name, NULL, 0);
1070                strbuf_addstr(&name, " => ");
1071                quote_c_style(b, &name, NULL, 0);
1072                return strbuf_detach(&name, NULL);
1073        }
1074
1075        /* Find common prefix */
1076        pfx_length = 0;
1077        while (*old && *new && *old == *new) {
1078                if (*old == '/')
1079                        pfx_length = old - a + 1;
1080                old++;
1081                new++;
1082        }
1083
1084        /* Find common suffix */
1085        old = a + len_a;
1086        new = b + len_b;
1087        sfx_length = 0;
1088        while (a <= old && b <= new && *old == *new) {
1089                if (*old == '/')
1090                        sfx_length = len_a - (old - a);
1091                old--;
1092                new--;
1093        }
1094
1095        /*
1096         * pfx{mid-a => mid-b}sfx
1097         * {pfx-a => pfx-b}sfx
1098         * pfx{sfx-a => sfx-b}
1099         * name-a => name-b
1100         */
1101        a_midlen = len_a - pfx_length - sfx_length;
1102        b_midlen = len_b - pfx_length - sfx_length;
1103        if (a_midlen < 0)
1104                a_midlen = 0;
1105        if (b_midlen < 0)
1106                b_midlen = 0;
1107
1108        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1109        if (pfx_length + sfx_length) {
1110                strbuf_add(&name, a, pfx_length);
1111                strbuf_addch(&name, '{');
1112        }
1113        strbuf_add(&name, a + pfx_length, a_midlen);
1114        strbuf_addstr(&name, " => ");
1115        strbuf_add(&name, b + pfx_length, b_midlen);
1116        if (pfx_length + sfx_length) {
1117                strbuf_addch(&name, '}');
1118                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1119        }
1120        return strbuf_detach(&name, NULL);
1121}
1122
1123struct diffstat_t {
1124        int nr;
1125        int alloc;
1126        struct diffstat_file {
1127                char *from_name;
1128                char *name;
1129                char *print_name;
1130                unsigned is_unmerged:1;
1131                unsigned is_binary:1;
1132                unsigned is_renamed:1;
1133                uintmax_t added, deleted;
1134        } **files;
1135};
1136
1137static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1138                                          const char *name_a,
1139                                          const char *name_b)
1140{
1141        struct diffstat_file *x;
1142        x = xcalloc(sizeof (*x), 1);
1143        if (diffstat->nr == diffstat->alloc) {
1144                diffstat->alloc = alloc_nr(diffstat->alloc);
1145                diffstat->files = xrealloc(diffstat->files,
1146                                diffstat->alloc * sizeof(x));
1147        }
1148        diffstat->files[diffstat->nr++] = x;
1149        if (name_b) {
1150                x->from_name = xstrdup(name_a);
1151                x->name = xstrdup(name_b);
1152                x->is_renamed = 1;
1153        }
1154        else {
1155                x->from_name = NULL;
1156                x->name = xstrdup(name_a);
1157        }
1158        return x;
1159}
1160
1161static void diffstat_consume(void *priv, char *line, unsigned long len)
1162{
1163        struct diffstat_t *diffstat = priv;
1164        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1165
1166        if (line[0] == '+')
1167                x->added++;
1168        else if (line[0] == '-')
1169                x->deleted++;
1170}
1171
1172const char mime_boundary_leader[] = "------------";
1173
1174static int scale_linear(int it, int width, int max_change)
1175{
1176        /*
1177         * make sure that at least one '-' is printed if there were deletions,
1178         * and likewise for '+'.
1179         */
1180        if (max_change < 2)
1181                return it;
1182        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1183}
1184
1185static void show_name(FILE *file,
1186                      const char *prefix, const char *name, int len)
1187{
1188        fprintf(file, " %s%-*s |", prefix, len, name);
1189}
1190
1191static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1192{
1193        if (cnt <= 0)
1194                return;
1195        fprintf(file, "%s", set);
1196        while (cnt--)
1197                putc(ch, file);
1198        fprintf(file, "%s", reset);
1199}
1200
1201static void fill_print_name(struct diffstat_file *file)
1202{
1203        char *pname;
1204
1205        if (file->print_name)
1206                return;
1207
1208        if (!file->is_renamed) {
1209                struct strbuf buf = STRBUF_INIT;
1210                if (quote_c_style(file->name, &buf, NULL, 0)) {
1211                        pname = strbuf_detach(&buf, NULL);
1212                } else {
1213                        pname = file->name;
1214                        strbuf_release(&buf);
1215                }
1216        } else {
1217                pname = pprint_rename(file->from_name, file->name);
1218        }
1219        file->print_name = pname;
1220}
1221
1222static void show_stats(struct diffstat_t *data, struct diff_options *options)
1223{
1224        int i, len, add, del, adds = 0, dels = 0;
1225        uintmax_t max_change = 0, max_len = 0;
1226        int total_files = data->nr;
1227        int width, name_width;
1228        const char *reset, *set, *add_c, *del_c;
1229        const char *line_prefix = "";
1230        struct strbuf *msg = NULL;
1231
1232        if (data->nr == 0)
1233                return;
1234
1235        if (options->output_prefix) {
1236                msg = options->output_prefix(options, options->output_prefix_data);
1237                line_prefix = msg->buf;
1238        }
1239
1240        width = options->stat_width ? options->stat_width : 80;
1241        name_width = options->stat_name_width ? options->stat_name_width : 50;
1242
1243        /* Sanity: give at least 5 columns to the graph,
1244         * but leave at least 10 columns for the name.
1245         */
1246        if (width < 25)
1247                width = 25;
1248        if (name_width < 10)
1249                name_width = 10;
1250        else if (width < name_width + 15)
1251                name_width = width - 15;
1252
1253        /* Find the longest filename and max number of changes */
1254        reset = diff_get_color_opt(options, DIFF_RESET);
1255        set   = diff_get_color_opt(options, DIFF_PLAIN);
1256        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1257        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1258
1259        for (i = 0; i < data->nr; i++) {
1260                struct diffstat_file *file = data->files[i];
1261                uintmax_t change = file->added + file->deleted;
1262                fill_print_name(file);
1263                len = strlen(file->print_name);
1264                if (max_len < len)
1265                        max_len = len;
1266
1267                if (file->is_binary || file->is_unmerged)
1268                        continue;
1269                if (max_change < change)
1270                        max_change = change;
1271        }
1272
1273        /* Compute the width of the graph part;
1274         * 10 is for one blank at the beginning of the line plus
1275         * " | count " between the name and the graph.
1276         *
1277         * From here on, name_width is the width of the name area,
1278         * and width is the width of the graph area.
1279         */
1280        name_width = (name_width < max_len) ? name_width : max_len;
1281        if (width < (name_width + 10) + max_change)
1282                width = width - (name_width + 10);
1283        else
1284                width = max_change;
1285
1286        for (i = 0; i < data->nr; i++) {
1287                const char *prefix = "";
1288                char *name = data->files[i]->print_name;
1289                uintmax_t added = data->files[i]->added;
1290                uintmax_t deleted = data->files[i]->deleted;
1291                int name_len;
1292
1293                /*
1294                 * "scale" the filename
1295                 */
1296                len = name_width;
1297                name_len = strlen(name);
1298                if (name_width < name_len) {
1299                        char *slash;
1300                        prefix = "...";
1301                        len -= 3;
1302                        name += name_len - len;
1303                        slash = strchr(name, '/');
1304                        if (slash)
1305                                name = slash;
1306                }
1307
1308                if (data->files[i]->is_binary) {
1309                        fprintf(options->file, "%s", line_prefix);
1310                        show_name(options->file, prefix, name, len);
1311                        fprintf(options->file, "  Bin ");
1312                        fprintf(options->file, "%s%"PRIuMAX"%s",
1313                                del_c, deleted, reset);
1314                        fprintf(options->file, " -> ");
1315                        fprintf(options->file, "%s%"PRIuMAX"%s",
1316                                add_c, added, reset);
1317                        fprintf(options->file, " bytes");
1318                        fprintf(options->file, "\n");
1319                        continue;
1320                }
1321                else if (data->files[i]->is_unmerged) {
1322                        fprintf(options->file, "%s", line_prefix);
1323                        show_name(options->file, prefix, name, len);
1324                        fprintf(options->file, "  Unmerged\n");
1325                        continue;
1326                }
1327                else if (!data->files[i]->is_renamed &&
1328                         (added + deleted == 0)) {
1329                        total_files--;
1330                        continue;
1331                }
1332
1333                /*
1334                 * scale the add/delete
1335                 */
1336                add = added;
1337                del = deleted;
1338                adds += add;
1339                dels += del;
1340
1341                if (width <= max_change) {
1342                        add = scale_linear(add, width, max_change);
1343                        del = scale_linear(del, width, max_change);
1344                }
1345                fprintf(options->file, "%s", line_prefix);
1346                show_name(options->file, prefix, name, len);
1347                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1348                                added + deleted ? " " : "");
1349                show_graph(options->file, '+', add, add_c, reset);
1350                show_graph(options->file, '-', del, del_c, reset);
1351                fprintf(options->file, "\n");
1352        }
1353        fprintf(options->file, "%s", line_prefix);
1354        fprintf(options->file,
1355               " %d files changed, %d insertions(+), %d deletions(-)\n",
1356               total_files, adds, dels);
1357}
1358
1359static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1360{
1361        int i, adds = 0, dels = 0, total_files = data->nr;
1362
1363        if (data->nr == 0)
1364                return;
1365
1366        for (i = 0; i < data->nr; i++) {
1367                if (!data->files[i]->is_binary &&
1368                    !data->files[i]->is_unmerged) {
1369                        int added = data->files[i]->added;
1370                        int deleted= data->files[i]->deleted;
1371                        if (!data->files[i]->is_renamed &&
1372                            (added + deleted == 0)) {
1373                                total_files--;
1374                        } else {
1375                                adds += added;
1376                                dels += deleted;
1377                        }
1378                }
1379        }
1380        if (options->output_prefix) {
1381                struct strbuf *msg = NULL;
1382                msg = options->output_prefix(options,
1383                                options->output_prefix_data);
1384                fprintf(options->file, "%s", msg->buf);
1385        }
1386        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1387               total_files, adds, dels);
1388}
1389
1390static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1391{
1392        int i;
1393
1394        if (data->nr == 0)
1395                return;
1396
1397        for (i = 0; i < data->nr; i++) {
1398                struct diffstat_file *file = data->files[i];
1399
1400                if (options->output_prefix) {
1401                        struct strbuf *msg = NULL;
1402                        msg = options->output_prefix(options,
1403                                        options->output_prefix_data);
1404                        fprintf(options->file, "%s", msg->buf);
1405                }
1406
1407                if (file->is_binary)
1408                        fprintf(options->file, "-\t-\t");
1409                else
1410                        fprintf(options->file,
1411                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1412                                file->added, file->deleted);
1413                if (options->line_termination) {
1414                        fill_print_name(file);
1415                        if (!file->is_renamed)
1416                                write_name_quoted(file->name, options->file,
1417                                                  options->line_termination);
1418                        else {
1419                                fputs(file->print_name, options->file);
1420                                putc(options->line_termination, options->file);
1421                        }
1422                } else {
1423                        if (file->is_renamed) {
1424                                putc('\0', options->file);
1425                                write_name_quoted(file->from_name, options->file, '\0');
1426                        }
1427                        write_name_quoted(file->name, options->file, '\0');
1428                }
1429        }
1430}
1431
1432struct dirstat_file {
1433        const char *name;
1434        unsigned long changed;
1435};
1436
1437struct dirstat_dir {
1438        struct dirstat_file *files;
1439        int alloc, nr, percent, cumulative;
1440};
1441
1442static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1443                unsigned long changed, const char *base, int baselen)
1444{
1445        unsigned long this_dir = 0;
1446        unsigned int sources = 0;
1447        const char *line_prefix = "";
1448        struct strbuf *msg = NULL;
1449
1450        if (opt->output_prefix) {
1451                msg = opt->output_prefix(opt, opt->output_prefix_data);
1452                line_prefix = msg->buf;
1453        }
1454
1455        while (dir->nr) {
1456                struct dirstat_file *f = dir->files;
1457                int namelen = strlen(f->name);
1458                unsigned long this;
1459                char *slash;
1460
1461                if (namelen < baselen)
1462                        break;
1463                if (memcmp(f->name, base, baselen))
1464                        break;
1465                slash = strchr(f->name + baselen, '/');
1466                if (slash) {
1467                        int newbaselen = slash + 1 - f->name;
1468                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1469                        sources++;
1470                } else {
1471                        this = f->changed;
1472                        dir->files++;
1473                        dir->nr--;
1474                        sources += 2;
1475                }
1476                this_dir += this;
1477        }
1478
1479        /*
1480         * We don't report dirstat's for
1481         *  - the top level
1482         *  - or cases where everything came from a single directory
1483         *    under this directory (sources == 1).
1484         */
1485        if (baselen && sources != 1) {
1486                int permille = this_dir * 1000 / changed;
1487                if (permille) {
1488                        int percent = permille / 10;
1489                        if (percent >= dir->percent) {
1490                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1491                                        percent, permille % 10, baselen, base);
1492                                if (!dir->cumulative)
1493                                        return 0;
1494                        }
1495                }
1496        }
1497        return this_dir;
1498}
1499
1500static int dirstat_compare(const void *_a, const void *_b)
1501{
1502        const struct dirstat_file *a = _a;
1503        const struct dirstat_file *b = _b;
1504        return strcmp(a->name, b->name);
1505}
1506
1507static void show_dirstat(struct diff_options *options)
1508{
1509        int i;
1510        unsigned long changed;
1511        struct dirstat_dir dir;
1512        struct diff_queue_struct *q = &diff_queued_diff;
1513
1514        dir.files = NULL;
1515        dir.alloc = 0;
1516        dir.nr = 0;
1517        dir.percent = options->dirstat_percent;
1518        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1519
1520        changed = 0;
1521        for (i = 0; i < q->nr; i++) {
1522                struct diff_filepair *p = q->queue[i];
1523                const char *name;
1524                unsigned long copied, added, damage;
1525
1526                name = p->one->path ? p->one->path : p->two->path;
1527
1528                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1529                        diff_populate_filespec(p->one, 0);
1530                        diff_populate_filespec(p->two, 0);
1531                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1532                                               &copied, &added);
1533                        diff_free_filespec_data(p->one);
1534                        diff_free_filespec_data(p->two);
1535                } else if (DIFF_FILE_VALID(p->one)) {
1536                        diff_populate_filespec(p->one, 1);
1537                        copied = added = 0;
1538                        diff_free_filespec_data(p->one);
1539                } else if (DIFF_FILE_VALID(p->two)) {
1540                        diff_populate_filespec(p->two, 1);
1541                        copied = 0;
1542                        added = p->two->size;
1543                        diff_free_filespec_data(p->two);
1544                } else
1545                        continue;
1546
1547                /*
1548                 * Original minus copied is the removed material,
1549                 * added is the new material.  They are both damages
1550                 * made to the preimage. In --dirstat-by-file mode, count
1551                 * damaged files, not damaged lines. This is done by
1552                 * counting only a single damaged line per file.
1553                 */
1554                damage = (p->one->size - copied) + added;
1555                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1556                        damage = 1;
1557
1558                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1559                dir.files[dir.nr].name = name;
1560                dir.files[dir.nr].changed = damage;
1561                changed += damage;
1562                dir.nr++;
1563        }
1564
1565        /* This can happen even with many files, if everything was renames */
1566        if (!changed)
1567                return;
1568
1569        /* Show all directories with more than x% of the changes */
1570        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1571        gather_dirstat(options, &dir, changed, "", 0);
1572}
1573
1574static void free_diffstat_info(struct diffstat_t *diffstat)
1575{
1576        int i;
1577        for (i = 0; i < diffstat->nr; i++) {
1578                struct diffstat_file *f = diffstat->files[i];
1579                if (f->name != f->print_name)
1580                        free(f->print_name);
1581                free(f->name);
1582                free(f->from_name);
1583                free(f);
1584        }
1585        free(diffstat->files);
1586}
1587
1588struct checkdiff_t {
1589        const char *filename;
1590        int lineno;
1591        int conflict_marker_size;
1592        struct diff_options *o;
1593        unsigned ws_rule;
1594        unsigned status;
1595};
1596
1597static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1598{
1599        char firstchar;
1600        int cnt;
1601
1602        if (len < marker_size + 1)
1603                return 0;
1604        firstchar = line[0];
1605        switch (firstchar) {
1606        case '=': case '>': case '<': case '|':
1607                break;
1608        default:
1609                return 0;
1610        }
1611        for (cnt = 1; cnt < marker_size; cnt++)
1612                if (line[cnt] != firstchar)
1613                        return 0;
1614        /* line[1] thru line[marker_size-1] are same as firstchar */
1615        if (len < marker_size + 1 || !isspace(line[marker_size]))
1616                return 0;
1617        return 1;
1618}
1619
1620static void checkdiff_consume(void *priv, char *line, unsigned long len)
1621{
1622        struct checkdiff_t *data = priv;
1623        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1624        int marker_size = data->conflict_marker_size;
1625        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1626        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1627        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1628        char *err;
1629        char *line_prefix = "";
1630        struct strbuf *msgbuf;
1631
1632        assert(data->o);
1633        if (data->o->output_prefix) {
1634                msgbuf = data->o->output_prefix(data->o,
1635                        data->o->output_prefix_data);
1636                line_prefix = msgbuf->buf;
1637        }
1638
1639        if (line[0] == '+') {
1640                unsigned bad;
1641                data->lineno++;
1642                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1643                        data->status |= 1;
1644                        fprintf(data->o->file,
1645                                "%s%s:%d: leftover conflict marker\n",
1646                                line_prefix, data->filename, data->lineno);
1647                }
1648                bad = ws_check(line + 1, len - 1, data->ws_rule);
1649                if (!bad)
1650                        return;
1651                data->status |= bad;
1652                err = whitespace_error_string(bad);
1653                fprintf(data->o->file, "%s%s:%d: %s.\n",
1654                        line_prefix, data->filename, data->lineno, err);
1655                free(err);
1656                emit_line(data->o, set, reset, line, 1);
1657                ws_check_emit(line + 1, len - 1, data->ws_rule,
1658                              data->o->file, set, reset, ws);
1659        } else if (line[0] == ' ') {
1660                data->lineno++;
1661        } else if (line[0] == '@') {
1662                char *plus = strchr(line, '+');
1663                if (plus)
1664                        data->lineno = strtol(plus, NULL, 10) - 1;
1665                else
1666                        die("invalid diff");
1667        }
1668}
1669
1670static unsigned char *deflate_it(char *data,
1671                                 unsigned long size,
1672                                 unsigned long *result_size)
1673{
1674        int bound;
1675        unsigned char *deflated;
1676        z_stream stream;
1677
1678        memset(&stream, 0, sizeof(stream));
1679        deflateInit(&stream, zlib_compression_level);
1680        bound = deflateBound(&stream, size);
1681        deflated = xmalloc(bound);
1682        stream.next_out = deflated;
1683        stream.avail_out = bound;
1684
1685        stream.next_in = (unsigned char *)data;
1686        stream.avail_in = size;
1687        while (deflate(&stream, Z_FINISH) == Z_OK)
1688                ; /* nothing */
1689        deflateEnd(&stream);
1690        *result_size = stream.total_out;
1691        return deflated;
1692}
1693
1694static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1695{
1696        void *cp;
1697        void *delta;
1698        void *deflated;
1699        void *data;
1700        unsigned long orig_size;
1701        unsigned long delta_size;
1702        unsigned long deflate_size;
1703        unsigned long data_size;
1704
1705        /* We could do deflated delta, or we could do just deflated two,
1706         * whichever is smaller.
1707         */
1708        delta = NULL;
1709        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1710        if (one->size && two->size) {
1711                delta = diff_delta(one->ptr, one->size,
1712                                   two->ptr, two->size,
1713                                   &delta_size, deflate_size);
1714                if (delta) {
1715                        void *to_free = delta;
1716                        orig_size = delta_size;
1717                        delta = deflate_it(delta, delta_size, &delta_size);
1718                        free(to_free);
1719                }
1720        }
1721
1722        if (delta && delta_size < deflate_size) {
1723                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1724                free(deflated);
1725                data = delta;
1726                data_size = delta_size;
1727        }
1728        else {
1729                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1730                free(delta);
1731                data = deflated;
1732                data_size = deflate_size;
1733        }
1734
1735        /* emit data encoded in base85 */
1736        cp = data;
1737        while (data_size) {
1738                int bytes = (52 < data_size) ? 52 : data_size;
1739                char line[70];
1740                data_size -= bytes;
1741                if (bytes <= 26)
1742                        line[0] = bytes + 'A' - 1;
1743                else
1744                        line[0] = bytes - 26 + 'a' - 1;
1745                encode_85(line + 1, cp, bytes);
1746                cp = (char *) cp + bytes;
1747                fprintf(file, "%s", prefix);
1748                fputs(line, file);
1749                fputc('\n', file);
1750        }
1751        fprintf(file, "%s\n", prefix);
1752        free(data);
1753}
1754
1755static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1756{
1757        fprintf(file, "%sGIT binary patch\n", prefix);
1758        emit_binary_diff_body(file, one, two, prefix);
1759        emit_binary_diff_body(file, two, one, prefix);
1760}
1761
1762static void diff_filespec_load_driver(struct diff_filespec *one)
1763{
1764        if (!one->driver)
1765                one->driver = userdiff_find_by_path(one->path);
1766        if (!one->driver)
1767                one->driver = userdiff_find_by_name("default");
1768}
1769
1770int diff_filespec_is_binary(struct diff_filespec *one)
1771{
1772        if (one->is_binary == -1) {
1773                diff_filespec_load_driver(one);
1774                if (one->driver->binary != -1)
1775                        one->is_binary = one->driver->binary;
1776                else {
1777                        if (!one->data && DIFF_FILE_VALID(one))
1778                                diff_populate_filespec(one, 0);
1779                        if (one->data)
1780                                one->is_binary = buffer_is_binary(one->data,
1781                                                one->size);
1782                        if (one->is_binary == -1)
1783                                one->is_binary = 0;
1784                }
1785        }
1786        return one->is_binary;
1787}
1788
1789static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1790{
1791        diff_filespec_load_driver(one);
1792        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1793}
1794
1795static const char *userdiff_word_regex(struct diff_filespec *one)
1796{
1797        diff_filespec_load_driver(one);
1798        return one->driver->word_regex;
1799}
1800
1801void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1802{
1803        if (!options->a_prefix)
1804                options->a_prefix = a;
1805        if (!options->b_prefix)
1806                options->b_prefix = b;
1807}
1808
1809struct userdiff_driver *get_textconv(struct diff_filespec *one)
1810{
1811        if (!DIFF_FILE_VALID(one))
1812                return NULL;
1813        if (!S_ISREG(one->mode))
1814                return NULL;
1815        diff_filespec_load_driver(one);
1816        if (!one->driver->textconv)
1817                return NULL;
1818
1819        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1820                struct notes_cache *c = xmalloc(sizeof(*c));
1821                struct strbuf name = STRBUF_INIT;
1822
1823                strbuf_addf(&name, "textconv/%s", one->driver->name);
1824                notes_cache_init(c, name.buf, one->driver->textconv);
1825                one->driver->textconv_cache = c;
1826        }
1827
1828        return one->driver;
1829}
1830
1831static void builtin_diff(const char *name_a,
1832                         const char *name_b,
1833                         struct diff_filespec *one,
1834                         struct diff_filespec *two,
1835                         const char *xfrm_msg,
1836                         int must_show_header,
1837                         struct diff_options *o,
1838                         int complete_rewrite)
1839{
1840        mmfile_t mf1, mf2;
1841        const char *lbl[2];
1842        char *a_one, *b_two;
1843        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1844        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1845        const char *a_prefix, *b_prefix;
1846        struct userdiff_driver *textconv_one = NULL;
1847        struct userdiff_driver *textconv_two = NULL;
1848        struct strbuf header = STRBUF_INIT;
1849        struct strbuf *msgbuf;
1850        char *line_prefix = "";
1851
1852        if (o->output_prefix) {
1853                msgbuf = o->output_prefix(o, o->output_prefix_data);
1854                line_prefix = msgbuf->buf;
1855        }
1856
1857        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1858                        (!one->mode || S_ISGITLINK(one->mode)) &&
1859                        (!two->mode || S_ISGITLINK(two->mode))) {
1860                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1861                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1862                show_submodule_summary(o->file, one ? one->path : two->path,
1863                                one->sha1, two->sha1, two->dirty_submodule,
1864                                del, add, reset);
1865                return;
1866        }
1867
1868        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1869                textconv_one = get_textconv(one);
1870                textconv_two = get_textconv(two);
1871        }
1872
1873        diff_set_mnemonic_prefix(o, "a/", "b/");
1874        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1875                a_prefix = o->b_prefix;
1876                b_prefix = o->a_prefix;
1877        } else {
1878                a_prefix = o->a_prefix;
1879                b_prefix = o->b_prefix;
1880        }
1881
1882        /* Never use a non-valid filename anywhere if at all possible */
1883        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1884        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1885
1886        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1887        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1888        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1889        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1890        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1891        if (lbl[0][0] == '/') {
1892                /* /dev/null */
1893                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1894                if (xfrm_msg)
1895                        strbuf_addstr(&header, xfrm_msg);
1896                must_show_header = 1;
1897        }
1898        else if (lbl[1][0] == '/') {
1899                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1900                if (xfrm_msg)
1901                        strbuf_addstr(&header, xfrm_msg);
1902                must_show_header = 1;
1903        }
1904        else {
1905                if (one->mode != two->mode) {
1906                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1907                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1908                        must_show_header = 1;
1909                }
1910                if (xfrm_msg)
1911                        strbuf_addstr(&header, xfrm_msg);
1912
1913                /*
1914                 * we do not run diff between different kind
1915                 * of objects.
1916                 */
1917                if ((one->mode ^ two->mode) & S_IFMT)
1918                        goto free_ab_and_return;
1919                if (complete_rewrite &&
1920                    (textconv_one || !diff_filespec_is_binary(one)) &&
1921                    (textconv_two || !diff_filespec_is_binary(two))) {
1922                        fprintf(o->file, "%s", header.buf);
1923                        strbuf_reset(&header);
1924                        emit_rewrite_diff(name_a, name_b, one, two,
1925                                                textconv_one, textconv_two, o);
1926                        o->found_changes = 1;
1927                        goto free_ab_and_return;
1928                }
1929        }
1930
1931        if (!DIFF_OPT_TST(o, TEXT) &&
1932            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1933              (!textconv_two && diff_filespec_is_binary(two)) )) {
1934                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1935                        die("unable to read files to diff");
1936                /* Quite common confusing case */
1937                if (mf1.size == mf2.size &&
1938                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1939                        if (must_show_header)
1940                                fprintf(o->file, "%s", header.buf);
1941                        goto free_ab_and_return;
1942                }
1943                fprintf(o->file, "%s", header.buf);
1944                strbuf_reset(&header);
1945                if (DIFF_OPT_TST(o, BINARY))
1946                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1947                else
1948                        fprintf(o->file, "%sBinary files %s and %s differ\n",
1949                                line_prefix, lbl[0], lbl[1]);
1950                o->found_changes = 1;
1951        }
1952        else {
1953                /* Crazy xdl interfaces.. */
1954                const char *diffopts = getenv("GIT_DIFF_OPTS");
1955                xpparam_t xpp;
1956                xdemitconf_t xecfg;
1957                struct emit_callback ecbdata;
1958                const struct userdiff_funcname *pe;
1959
1960                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
1961                        fprintf(o->file, "%s", header.buf);
1962                        strbuf_reset(&header);
1963                }
1964
1965                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1966                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1967
1968                pe = diff_funcname_pattern(one);
1969                if (!pe)
1970                        pe = diff_funcname_pattern(two);
1971
1972                memset(&xpp, 0, sizeof(xpp));
1973                memset(&xecfg, 0, sizeof(xecfg));
1974                memset(&ecbdata, 0, sizeof(ecbdata));
1975                ecbdata.label_path = lbl;
1976                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1977                ecbdata.found_changesp = &o->found_changes;
1978                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1979                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1980                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1981                ecbdata.opt = o;
1982                ecbdata.header = header.len ? &header : NULL;
1983                xpp.flags = o->xdl_opts;
1984                xecfg.ctxlen = o->context;
1985                xecfg.interhunkctxlen = o->interhunkcontext;
1986                xecfg.flags = XDL_EMIT_FUNCNAMES;
1987                if (pe)
1988                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1989                if (!diffopts)
1990                        ;
1991                else if (!prefixcmp(diffopts, "--unified="))
1992                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1993                else if (!prefixcmp(diffopts, "-u"))
1994                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1995                if (o->word_diff) {
1996                        int i;
1997
1998                        ecbdata.diff_words =
1999                                xcalloc(1, sizeof(struct diff_words_data));
2000                        ecbdata.diff_words->type = o->word_diff;
2001                        ecbdata.diff_words->opt = o;
2002                        if (!o->word_regex)
2003                                o->word_regex = userdiff_word_regex(one);
2004                        if (!o->word_regex)
2005                                o->word_regex = userdiff_word_regex(two);
2006                        if (!o->word_regex)
2007                                o->word_regex = diff_word_regex_cfg;
2008                        if (o->word_regex) {
2009                                ecbdata.diff_words->word_regex = (regex_t *)
2010                                        xmalloc(sizeof(regex_t));
2011                                if (regcomp(ecbdata.diff_words->word_regex,
2012                                                o->word_regex,
2013                                                REG_EXTENDED | REG_NEWLINE))
2014                                        die ("Invalid regular expression: %s",
2015                                                        o->word_regex);
2016                        }
2017                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2018                                if (o->word_diff == diff_words_styles[i].type) {
2019                                        ecbdata.diff_words->style =
2020                                                &diff_words_styles[i];
2021                                        break;
2022                                }
2023                        }
2024                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2025                                struct diff_words_style *st = ecbdata.diff_words->style;
2026                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2027                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2028                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2029                        }
2030                }
2031                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2032                              &xpp, &xecfg);
2033                if (o->word_diff)
2034                        free_diff_words_data(&ecbdata);
2035                if (textconv_one)
2036                        free(mf1.ptr);
2037                if (textconv_two)
2038                        free(mf2.ptr);
2039                xdiff_clear_find_func(&xecfg);
2040        }
2041
2042 free_ab_and_return:
2043        strbuf_release(&header);
2044        diff_free_filespec_data(one);
2045        diff_free_filespec_data(two);
2046        free(a_one);
2047        free(b_two);
2048        return;
2049}
2050
2051static void builtin_diffstat(const char *name_a, const char *name_b,
2052                             struct diff_filespec *one,
2053                             struct diff_filespec *two,
2054                             struct diffstat_t *diffstat,
2055                             struct diff_options *o,
2056                             int complete_rewrite)
2057{
2058        mmfile_t mf1, mf2;
2059        struct diffstat_file *data;
2060
2061        data = diffstat_add(diffstat, name_a, name_b);
2062
2063        if (!one || !two) {
2064                data->is_unmerged = 1;
2065                return;
2066        }
2067        if (complete_rewrite) {
2068                diff_populate_filespec(one, 0);
2069                diff_populate_filespec(two, 0);
2070                data->deleted = count_lines(one->data, one->size);
2071                data->added = count_lines(two->data, two->size);
2072                goto free_and_return;
2073        }
2074        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2075                die("unable to read files to diff");
2076
2077        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2078                data->is_binary = 1;
2079                data->added = mf2.size;
2080                data->deleted = mf1.size;
2081        } else {
2082                /* Crazy xdl interfaces.. */
2083                xpparam_t xpp;
2084                xdemitconf_t xecfg;
2085
2086                memset(&xpp, 0, sizeof(xpp));
2087                memset(&xecfg, 0, sizeof(xecfg));
2088                xpp.flags = o->xdl_opts;
2089                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2090                              &xpp, &xecfg);
2091        }
2092
2093 free_and_return:
2094        diff_free_filespec_data(one);
2095        diff_free_filespec_data(two);
2096}
2097
2098static void builtin_checkdiff(const char *name_a, const char *name_b,
2099                              const char *attr_path,
2100                              struct diff_filespec *one,
2101                              struct diff_filespec *two,
2102                              struct diff_options *o)
2103{
2104        mmfile_t mf1, mf2;
2105        struct checkdiff_t data;
2106
2107        if (!two)
2108                return;
2109
2110        memset(&data, 0, sizeof(data));
2111        data.filename = name_b ? name_b : name_a;
2112        data.lineno = 0;
2113        data.o = o;
2114        data.ws_rule = whitespace_rule(attr_path);
2115        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2116
2117        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2118                die("unable to read files to diff");
2119
2120        /*
2121         * All the other codepaths check both sides, but not checking
2122         * the "old" side here is deliberate.  We are checking the newly
2123         * introduced changes, and as long as the "new" side is text, we
2124         * can and should check what it introduces.
2125         */
2126        if (diff_filespec_is_binary(two))
2127                goto free_and_return;
2128        else {
2129                /* Crazy xdl interfaces.. */
2130                xpparam_t xpp;
2131                xdemitconf_t xecfg;
2132
2133                memset(&xpp, 0, sizeof(xpp));
2134                memset(&xecfg, 0, sizeof(xecfg));
2135                xecfg.ctxlen = 1; /* at least one context line */
2136                xpp.flags = 0;
2137                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2138                              &xpp, &xecfg);
2139
2140                if (data.ws_rule & WS_BLANK_AT_EOF) {
2141                        struct emit_callback ecbdata;
2142                        int blank_at_eof;
2143
2144                        ecbdata.ws_rule = data.ws_rule;
2145                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2146                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
2147
2148                        if (blank_at_eof) {
2149                                static char *err;
2150                                if (!err)
2151                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2152                                fprintf(o->file, "%s:%d: %s.\n",
2153                                        data.filename, blank_at_eof, err);
2154                                data.status = 1; /* report errors */
2155                        }
2156                }
2157        }
2158 free_and_return:
2159        diff_free_filespec_data(one);
2160        diff_free_filespec_data(two);
2161        if (data.status)
2162                DIFF_OPT_SET(o, CHECK_FAILED);
2163}
2164
2165struct diff_filespec *alloc_filespec(const char *path)
2166{
2167        int namelen = strlen(path);
2168        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2169
2170        memset(spec, 0, sizeof(*spec));
2171        spec->path = (char *)(spec + 1);
2172        memcpy(spec->path, path, namelen+1);
2173        spec->count = 1;
2174        spec->is_binary = -1;
2175        return spec;
2176}
2177
2178void free_filespec(struct diff_filespec *spec)
2179{
2180        if (!--spec->count) {
2181                diff_free_filespec_data(spec);
2182                free(spec);
2183        }
2184}
2185
2186void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2187                   unsigned short mode)
2188{
2189        if (mode) {
2190                spec->mode = canon_mode(mode);
2191                hashcpy(spec->sha1, sha1);
2192                spec->sha1_valid = !is_null_sha1(sha1);
2193        }
2194}
2195
2196/*
2197 * Given a name and sha1 pair, if the index tells us the file in
2198 * the work tree has that object contents, return true, so that
2199 * prepare_temp_file() does not have to inflate and extract.
2200 */
2201static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2202{
2203        struct cache_entry *ce;
2204        struct stat st;
2205        int pos, len;
2206
2207        /*
2208         * We do not read the cache ourselves here, because the
2209         * benchmark with my previous version that always reads cache
2210         * shows that it makes things worse for diff-tree comparing
2211         * two linux-2.6 kernel trees in an already checked out work
2212         * tree.  This is because most diff-tree comparisons deal with
2213         * only a small number of files, while reading the cache is
2214         * expensive for a large project, and its cost outweighs the
2215         * savings we get by not inflating the object to a temporary
2216         * file.  Practically, this code only helps when we are used
2217         * by diff-cache --cached, which does read the cache before
2218         * calling us.
2219         */
2220        if (!active_cache)
2221                return 0;
2222
2223        /* We want to avoid the working directory if our caller
2224         * doesn't need the data in a normal file, this system
2225         * is rather slow with its stat/open/mmap/close syscalls,
2226         * and the object is contained in a pack file.  The pack
2227         * is probably already open and will be faster to obtain
2228         * the data through than the working directory.  Loose
2229         * objects however would tend to be slower as they need
2230         * to be individually opened and inflated.
2231         */
2232        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2233                return 0;
2234
2235        len = strlen(name);
2236        pos = cache_name_pos(name, len);
2237        if (pos < 0)
2238                return 0;
2239        ce = active_cache[pos];
2240
2241        /*
2242         * This is not the sha1 we are looking for, or
2243         * unreusable because it is not a regular file.
2244         */
2245        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2246                return 0;
2247
2248        /*
2249         * If ce is marked as "assume unchanged", there is no
2250         * guarantee that work tree matches what we are looking for.
2251         */
2252        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2253                return 0;
2254
2255        /*
2256         * If ce matches the file in the work tree, we can reuse it.
2257         */
2258        if (ce_uptodate(ce) ||
2259            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2260                return 1;
2261
2262        return 0;
2263}
2264
2265static int populate_from_stdin(struct diff_filespec *s)
2266{
2267        struct strbuf buf = STRBUF_INIT;
2268        size_t size = 0;
2269
2270        if (strbuf_read(&buf, 0, 0) < 0)
2271                return error("error while reading from stdin %s",
2272                                     strerror(errno));
2273
2274        s->should_munmap = 0;
2275        s->data = strbuf_detach(&buf, &size);
2276        s->size = size;
2277        s->should_free = 1;
2278        return 0;
2279}
2280
2281static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2282{
2283        int len;
2284        char *data = xmalloc(100), *dirty = "";
2285
2286        /* Are we looking at the work tree? */
2287        if (s->dirty_submodule)
2288                dirty = "-dirty";
2289
2290        len = snprintf(data, 100,
2291                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2292        s->data = data;
2293        s->size = len;
2294        s->should_free = 1;
2295        if (size_only) {
2296                s->data = NULL;
2297                free(data);
2298        }
2299        return 0;
2300}
2301
2302/*
2303 * While doing rename detection and pickaxe operation, we may need to
2304 * grab the data for the blob (or file) for our own in-core comparison.
2305 * diff_filespec has data and size fields for this purpose.
2306 */
2307int diff_populate_filespec(struct diff_filespec *s, int size_only)
2308{
2309        int err = 0;
2310        if (!DIFF_FILE_VALID(s))
2311                die("internal error: asking to populate invalid file.");
2312        if (S_ISDIR(s->mode))
2313                return -1;
2314
2315        if (s->data)
2316                return 0;
2317
2318        if (size_only && 0 < s->size)
2319                return 0;
2320
2321        if (S_ISGITLINK(s->mode))
2322                return diff_populate_gitlink(s, size_only);
2323
2324        if (!s->sha1_valid ||
2325            reuse_worktree_file(s->path, s->sha1, 0)) {
2326                struct strbuf buf = STRBUF_INIT;
2327                struct stat st;
2328                int fd;
2329
2330                if (!strcmp(s->path, "-"))
2331                        return populate_from_stdin(s);
2332
2333                if (lstat(s->path, &st) < 0) {
2334                        if (errno == ENOENT) {
2335                        err_empty:
2336                                err = -1;
2337                        empty:
2338                                s->data = (char *)"";
2339                                s->size = 0;
2340                                return err;
2341                        }
2342                }
2343                s->size = xsize_t(st.st_size);
2344                if (!s->size)
2345                        goto empty;
2346                if (S_ISLNK(st.st_mode)) {
2347                        struct strbuf sb = STRBUF_INIT;
2348
2349                        if (strbuf_readlink(&sb, s->path, s->size))
2350                                goto err_empty;
2351                        s->size = sb.len;
2352                        s->data = strbuf_detach(&sb, NULL);
2353                        s->should_free = 1;
2354                        return 0;
2355                }
2356                if (size_only)
2357                        return 0;
2358                fd = open(s->path, O_RDONLY);
2359                if (fd < 0)
2360                        goto err_empty;
2361                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2362                close(fd);
2363                s->should_munmap = 1;
2364
2365                /*
2366                 * Convert from working tree format to canonical git format
2367                 */
2368                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2369                        size_t size = 0;
2370                        munmap(s->data, s->size);
2371                        s->should_munmap = 0;
2372                        s->data = strbuf_detach(&buf, &size);
2373                        s->size = size;
2374                        s->should_free = 1;
2375                }
2376        }
2377        else {
2378                enum object_type type;
2379                if (size_only)
2380                        type = sha1_object_info(s->sha1, &s->size);
2381                else {
2382                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2383                        s->should_free = 1;
2384                }
2385        }
2386        return 0;
2387}
2388
2389void diff_free_filespec_blob(struct diff_filespec *s)
2390{
2391        if (s->should_free)
2392                free(s->data);
2393        else if (s->should_munmap)
2394                munmap(s->data, s->size);
2395
2396        if (s->should_free || s->should_munmap) {
2397                s->should_free = s->should_munmap = 0;
2398                s->data = NULL;
2399        }
2400}
2401
2402void diff_free_filespec_data(struct diff_filespec *s)
2403{
2404        diff_free_filespec_blob(s);
2405        free(s->cnt_data);
2406        s->cnt_data = NULL;
2407}
2408
2409static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2410                           void *blob,
2411                           unsigned long size,
2412                           const unsigned char *sha1,
2413                           int mode)
2414{
2415        int fd;
2416        struct strbuf buf = STRBUF_INIT;
2417        struct strbuf template = STRBUF_INIT;
2418        char *path_dup = xstrdup(path);
2419        const char *base = basename(path_dup);
2420
2421        /* Generate "XXXXXX_basename.ext" */
2422        strbuf_addstr(&template, "XXXXXX_");
2423        strbuf_addstr(&template, base);
2424
2425        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2426                        strlen(base) + 1);
2427        if (fd < 0)
2428                die_errno("unable to create temp-file");
2429        if (convert_to_working_tree(path,
2430                        (const char *)blob, (size_t)size, &buf)) {
2431                blob = buf.buf;
2432                size = buf.len;
2433        }
2434        if (write_in_full(fd, blob, size) != size)
2435                die_errno("unable to write temp-file");
2436        close(fd);
2437        temp->name = temp->tmp_path;
2438        strcpy(temp->hex, sha1_to_hex(sha1));
2439        temp->hex[40] = 0;
2440        sprintf(temp->mode, "%06o", mode);
2441        strbuf_release(&buf);
2442        strbuf_release(&template);
2443        free(path_dup);
2444}
2445
2446static struct diff_tempfile *prepare_temp_file(const char *name,
2447                struct diff_filespec *one)
2448{
2449        struct diff_tempfile *temp = claim_diff_tempfile();
2450
2451        if (!DIFF_FILE_VALID(one)) {
2452        not_a_valid_file:
2453                /* A '-' entry produces this for file-2, and
2454                 * a '+' entry produces this for file-1.
2455                 */
2456                temp->name = "/dev/null";
2457                strcpy(temp->hex, ".");
2458                strcpy(temp->mode, ".");
2459                return temp;
2460        }
2461
2462        if (!remove_tempfile_installed) {
2463                atexit(remove_tempfile);
2464                sigchain_push_common(remove_tempfile_on_signal);
2465                remove_tempfile_installed = 1;
2466        }
2467
2468        if (!one->sha1_valid ||
2469            reuse_worktree_file(name, one->sha1, 1)) {
2470                struct stat st;
2471                if (lstat(name, &st) < 0) {
2472                        if (errno == ENOENT)
2473                                goto not_a_valid_file;
2474                        die_errno("stat(%s)", name);
2475                }
2476                if (S_ISLNK(st.st_mode)) {
2477                        struct strbuf sb = STRBUF_INIT;
2478                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2479                                die_errno("readlink(%s)", name);
2480                        prep_temp_blob(name, temp, sb.buf, sb.len,
2481                                       (one->sha1_valid ?
2482                                        one->sha1 : null_sha1),
2483                                       (one->sha1_valid ?
2484                                        one->mode : S_IFLNK));
2485                        strbuf_release(&sb);
2486                }
2487                else {
2488                        /* we can borrow from the file in the work tree */
2489                        temp->name = name;
2490                        if (!one->sha1_valid)
2491                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2492                        else
2493                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2494                        /* Even though we may sometimes borrow the
2495                         * contents from the work tree, we always want
2496                         * one->mode.  mode is trustworthy even when
2497                         * !(one->sha1_valid), as long as
2498                         * DIFF_FILE_VALID(one).
2499                         */
2500                        sprintf(temp->mode, "%06o", one->mode);
2501                }
2502                return temp;
2503        }
2504        else {
2505                if (diff_populate_filespec(one, 0))
2506                        die("cannot read data blob for %s", one->path);
2507                prep_temp_blob(name, temp, one->data, one->size,
2508                               one->sha1, one->mode);
2509        }
2510        return temp;
2511}
2512
2513/* An external diff command takes:
2514 *
2515 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2516 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2517 *
2518 */
2519static void run_external_diff(const char *pgm,
2520                              const char *name,
2521                              const char *other,
2522                              struct diff_filespec *one,
2523                              struct diff_filespec *two,
2524                              const char *xfrm_msg,
2525                              int complete_rewrite)
2526{
2527        const char *spawn_arg[10];
2528        int retval;
2529        const char **arg = &spawn_arg[0];
2530
2531        if (one && two) {
2532                struct diff_tempfile *temp_one, *temp_two;
2533                const char *othername = (other ? other : name);
2534                temp_one = prepare_temp_file(name, one);
2535                temp_two = prepare_temp_file(othername, two);
2536                *arg++ = pgm;
2537                *arg++ = name;
2538                *arg++ = temp_one->name;
2539                *arg++ = temp_one->hex;
2540                *arg++ = temp_one->mode;
2541                *arg++ = temp_two->name;
2542                *arg++ = temp_two->hex;
2543                *arg++ = temp_two->mode;
2544                if (other) {
2545                        *arg++ = other;
2546                        *arg++ = xfrm_msg;
2547                }
2548        } else {
2549                *arg++ = pgm;
2550                *arg++ = name;
2551        }
2552        *arg = NULL;
2553        fflush(NULL);
2554        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2555        remove_tempfile();
2556        if (retval) {
2557                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2558                exit(1);
2559        }
2560}
2561
2562static int similarity_index(struct diff_filepair *p)
2563{
2564        return p->score * 100 / MAX_SCORE;
2565}
2566
2567static void fill_metainfo(struct strbuf *msg,
2568                          const char *name,
2569                          const char *other,
2570                          struct diff_filespec *one,
2571                          struct diff_filespec *two,
2572                          struct diff_options *o,
2573                          struct diff_filepair *p,
2574                          int *must_show_header,
2575                          int use_color)
2576{
2577        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2578        const char *reset = diff_get_color(use_color, DIFF_RESET);
2579        struct strbuf *msgbuf;
2580        char *line_prefix = "";
2581
2582        *must_show_header = 1;
2583        if (o->output_prefix) {
2584                msgbuf = o->output_prefix(o, o->output_prefix_data);
2585                line_prefix = msgbuf->buf;
2586        }
2587        strbuf_init(msg, PATH_MAX * 2 + 300);
2588        switch (p->status) {
2589        case DIFF_STATUS_COPIED:
2590                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2591                            line_prefix, set, similarity_index(p));
2592                strbuf_addf(msg, "%s\n%s%scopy from ",
2593                            reset,  line_prefix, set);
2594                quote_c_style(name, msg, NULL, 0);
2595                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2596                quote_c_style(other, msg, NULL, 0);
2597                strbuf_addf(msg, "%s\n", reset);
2598                break;
2599        case DIFF_STATUS_RENAMED:
2600                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2601                            line_prefix, set, similarity_index(p));
2602                strbuf_addf(msg, "%s\n%s%srename from ",
2603                            reset, line_prefix, set);
2604                quote_c_style(name, msg, NULL, 0);
2605                strbuf_addf(msg, "%s\n%s%srename to ",
2606                            reset, line_prefix, set);
2607                quote_c_style(other, msg, NULL, 0);
2608                strbuf_addf(msg, "%s\n", reset);
2609                break;
2610        case DIFF_STATUS_MODIFIED:
2611                if (p->score) {
2612                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2613                                    line_prefix,
2614                                    set, similarity_index(p), reset);
2615                        break;
2616                }
2617                /* fallthru */
2618        default:
2619                *must_show_header = 0;
2620        }
2621        if (one && two && hashcmp(one->sha1, two->sha1)) {
2622                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2623
2624                if (DIFF_OPT_TST(o, BINARY)) {
2625                        mmfile_t mf;
2626                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2627                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2628                                abbrev = 40;
2629                }
2630                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2631                            find_unique_abbrev(one->sha1, abbrev));
2632                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2633                if (one->mode == two->mode)
2634                        strbuf_addf(msg, " %06o", one->mode);
2635                strbuf_addf(msg, "%s\n", reset);
2636        }
2637}
2638
2639static void run_diff_cmd(const char *pgm,
2640                         const char *name,
2641                         const char *other,
2642                         const char *attr_path,
2643                         struct diff_filespec *one,
2644                         struct diff_filespec *two,
2645                         struct strbuf *msg,
2646                         struct diff_options *o,
2647                         struct diff_filepair *p)
2648{
2649        const char *xfrm_msg = NULL;
2650        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2651        int must_show_header = 0;
2652
2653        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2654                pgm = NULL;
2655        else {
2656                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2657                if (drv && drv->external)
2658                        pgm = drv->external;
2659        }
2660
2661        if (msg) {
2662                /*
2663                 * don't use colors when the header is intended for an
2664                 * external diff driver
2665                 */
2666                fill_metainfo(msg, name, other, one, two, o, p,
2667                              &must_show_header,
2668                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2669                xfrm_msg = msg->len ? msg->buf : NULL;
2670        }
2671
2672        if (pgm) {
2673                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2674                                  complete_rewrite);
2675                return;
2676        }
2677        if (one && two)
2678                builtin_diff(name, other ? other : name,
2679                             one, two, xfrm_msg, must_show_header,
2680                             o, complete_rewrite);
2681        else
2682                fprintf(o->file, "* Unmerged path %s\n", name);
2683}
2684
2685static void diff_fill_sha1_info(struct diff_filespec *one)
2686{
2687        if (DIFF_FILE_VALID(one)) {
2688                if (!one->sha1_valid) {
2689                        struct stat st;
2690                        if (!strcmp(one->path, "-")) {
2691                                hashcpy(one->sha1, null_sha1);
2692                                return;
2693                        }
2694                        if (lstat(one->path, &st) < 0)
2695                                die_errno("stat '%s'", one->path);
2696                        if (index_path(one->sha1, one->path, &st, 0))
2697                                die("cannot hash %s", one->path);
2698                }
2699        }
2700        else
2701                hashclr(one->sha1);
2702}
2703
2704static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2705{
2706        /* Strip the prefix but do not molest /dev/null and absolute paths */
2707        if (*namep && **namep != '/')
2708                *namep += prefix_length;
2709        if (*otherp && **otherp != '/')
2710                *otherp += prefix_length;
2711}
2712
2713static void run_diff(struct diff_filepair *p, struct diff_options *o)
2714{
2715        const char *pgm = external_diff();
2716        struct strbuf msg;
2717        struct diff_filespec *one = p->one;
2718        struct diff_filespec *two = p->two;
2719        const char *name;
2720        const char *other;
2721        const char *attr_path;
2722
2723        name  = p->one->path;
2724        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2725        attr_path = name;
2726        if (o->prefix_length)
2727                strip_prefix(o->prefix_length, &name, &other);
2728
2729        if (DIFF_PAIR_UNMERGED(p)) {
2730                run_diff_cmd(pgm, name, NULL, attr_path,
2731                             NULL, NULL, NULL, o, p);
2732                return;
2733        }
2734
2735        diff_fill_sha1_info(one);
2736        diff_fill_sha1_info(two);
2737
2738        if (!pgm &&
2739            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2740            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2741                /*
2742                 * a filepair that changes between file and symlink
2743                 * needs to be split into deletion and creation.
2744                 */
2745                struct diff_filespec *null = alloc_filespec(two->path);
2746                run_diff_cmd(NULL, name, other, attr_path,
2747                             one, null, &msg, o, p);
2748                free(null);
2749                strbuf_release(&msg);
2750
2751                null = alloc_filespec(one->path);
2752                run_diff_cmd(NULL, name, other, attr_path,
2753                             null, two, &msg, o, p);
2754                free(null);
2755        }
2756        else
2757                run_diff_cmd(pgm, name, other, attr_path,
2758                             one, two, &msg, o, p);
2759
2760        strbuf_release(&msg);
2761}
2762
2763static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2764                         struct diffstat_t *diffstat)
2765{
2766        const char *name;
2767        const char *other;
2768        int complete_rewrite = 0;
2769
2770        if (DIFF_PAIR_UNMERGED(p)) {
2771                /* unmerged */
2772                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2773                return;
2774        }
2775
2776        name = p->one->path;
2777        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2778
2779        if (o->prefix_length)
2780                strip_prefix(o->prefix_length, &name, &other);
2781
2782        diff_fill_sha1_info(p->one);
2783        diff_fill_sha1_info(p->two);
2784
2785        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2786                complete_rewrite = 1;
2787        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2788}
2789
2790static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2791{
2792        const char *name;
2793        const char *other;
2794        const char *attr_path;
2795
2796        if (DIFF_PAIR_UNMERGED(p)) {
2797                /* unmerged */
2798                return;
2799        }
2800
2801        name = p->one->path;
2802        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2803        attr_path = other ? other : name;
2804
2805        if (o->prefix_length)
2806                strip_prefix(o->prefix_length, &name, &other);
2807
2808        diff_fill_sha1_info(p->one);
2809        diff_fill_sha1_info(p->two);
2810
2811        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2812}
2813
2814void diff_setup(struct diff_options *options)
2815{
2816        memset(options, 0, sizeof(*options));
2817        memset(&diff_queued_diff, 0, sizeof(diff_queued_diff));
2818
2819        options->file = stdout;
2820
2821        options->line_termination = '\n';
2822        options->break_opt = -1;
2823        options->rename_limit = -1;
2824        options->dirstat_percent = 3;
2825        options->context = 3;
2826
2827        options->change = diff_change;
2828        options->add_remove = diff_addremove;
2829        if (diff_use_color_default > 0)
2830                DIFF_OPT_SET(options, COLOR_DIFF);
2831        options->detect_rename = diff_detect_rename_default;
2832
2833        if (diff_no_prefix) {
2834                options->a_prefix = options->b_prefix = "";
2835        } else if (!diff_mnemonic_prefix) {
2836                options->a_prefix = "a/";
2837                options->b_prefix = "b/";
2838        }
2839}
2840
2841int diff_setup_done(struct diff_options *options)
2842{
2843        int count = 0;
2844
2845        if (options->output_format & DIFF_FORMAT_NAME)
2846                count++;
2847        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2848                count++;
2849        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2850                count++;
2851        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2852                count++;
2853        if (count > 1)
2854                die("--name-only, --name-status, --check and -s are mutually exclusive");
2855
2856        /*
2857         * Most of the time we can say "there are changes"
2858         * only by checking if there are changed paths, but
2859         * --ignore-whitespace* options force us to look
2860         * inside contents.
2861         */
2862
2863        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2864            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2865            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2866                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2867        else
2868                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2869
2870        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2871                options->detect_rename = DIFF_DETECT_COPY;
2872
2873        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2874                options->prefix = NULL;
2875        if (options->prefix)
2876                options->prefix_length = strlen(options->prefix);
2877        else
2878                options->prefix_length = 0;
2879
2880        if (options->output_format & (DIFF_FORMAT_NAME |
2881                                      DIFF_FORMAT_NAME_STATUS |
2882                                      DIFF_FORMAT_CHECKDIFF |
2883                                      DIFF_FORMAT_NO_OUTPUT))
2884                options->output_format &= ~(DIFF_FORMAT_RAW |
2885                                            DIFF_FORMAT_NUMSTAT |
2886                                            DIFF_FORMAT_DIFFSTAT |
2887                                            DIFF_FORMAT_SHORTSTAT |
2888                                            DIFF_FORMAT_DIRSTAT |
2889                                            DIFF_FORMAT_SUMMARY |
2890                                            DIFF_FORMAT_PATCH);
2891
2892        /*
2893         * These cases always need recursive; we do not drop caller-supplied
2894         * recursive bits for other formats here.
2895         */
2896        if (options->output_format & (DIFF_FORMAT_PATCH |
2897                                      DIFF_FORMAT_NUMSTAT |
2898                                      DIFF_FORMAT_DIFFSTAT |
2899                                      DIFF_FORMAT_SHORTSTAT |
2900                                      DIFF_FORMAT_DIRSTAT |
2901                                      DIFF_FORMAT_SUMMARY |
2902                                      DIFF_FORMAT_CHECKDIFF))
2903                DIFF_OPT_SET(options, RECURSIVE);
2904        /*
2905         * Also pickaxe would not work very well if you do not say recursive
2906         */
2907        if (options->pickaxe)
2908                DIFF_OPT_SET(options, RECURSIVE);
2909        /*
2910         * When patches are generated, submodules diffed against the work tree
2911         * must be checked for dirtiness too so it can be shown in the output
2912         */
2913        if (options->output_format & DIFF_FORMAT_PATCH)
2914                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2915
2916        if (options->detect_rename && options->rename_limit < 0)
2917                options->rename_limit = diff_rename_limit_default;
2918        if (options->setup & DIFF_SETUP_USE_CACHE) {
2919                if (!active_cache)
2920                        /* read-cache does not die even when it fails
2921                         * so it is safe for us to do this here.  Also
2922                         * it does not smudge active_cache or active_nr
2923                         * when it fails, so we do not have to worry about
2924                         * cleaning it up ourselves either.
2925                         */
2926                        read_cache();
2927        }
2928        if (options->abbrev <= 0 || 40 < options->abbrev)
2929                options->abbrev = 40; /* full */
2930
2931        /*
2932         * It does not make sense to show the first hit we happened
2933         * to have found.  It does not make sense not to return with
2934         * exit code in such a case either.
2935         */
2936        if (DIFF_OPT_TST(options, QUICK)) {
2937                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2938                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2939        }
2940
2941        return 0;
2942}
2943
2944static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2945{
2946        char c, *eq;
2947        int len;
2948
2949        if (*arg != '-')
2950                return 0;
2951        c = *++arg;
2952        if (!c)
2953                return 0;
2954        if (c == arg_short) {
2955                c = *++arg;
2956                if (!c)
2957                        return 1;
2958                if (val && isdigit(c)) {
2959                        char *end;
2960                        int n = strtoul(arg, &end, 10);
2961                        if (*end)
2962                                return 0;
2963                        *val = n;
2964                        return 1;
2965                }
2966                return 0;
2967        }
2968        if (c != '-')
2969                return 0;
2970        arg++;
2971        eq = strchr(arg, '=');
2972        if (eq)
2973                len = eq - arg;
2974        else
2975                len = strlen(arg);
2976        if (!len || strncmp(arg, arg_long, len))
2977                return 0;
2978        if (eq) {
2979                int n;
2980                char *end;
2981                if (!isdigit(*++eq))
2982                        return 0;
2983                n = strtoul(eq, &end, 10);
2984                if (*end)
2985                        return 0;
2986                *val = n;
2987        }
2988        return 1;
2989}
2990
2991static int diff_scoreopt_parse(const char *opt);
2992
2993int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2994{
2995        const char *arg = av[0];
2996
2997        /* Output format options */
2998        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
2999                options->output_format |= DIFF_FORMAT_PATCH;
3000        else if (opt_arg(arg, 'U', "unified", &options->context))
3001                options->output_format |= DIFF_FORMAT_PATCH;
3002        else if (!strcmp(arg, "--raw"))
3003                options->output_format |= DIFF_FORMAT_RAW;
3004        else if (!strcmp(arg, "--patch-with-raw"))
3005                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3006        else if (!strcmp(arg, "--numstat"))
3007                options->output_format |= DIFF_FORMAT_NUMSTAT;
3008        else if (!strcmp(arg, "--shortstat"))
3009                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3010        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3011                options->output_format |= DIFF_FORMAT_DIRSTAT;
3012        else if (!strcmp(arg, "--cumulative")) {
3013                options->output_format |= DIFF_FORMAT_DIRSTAT;
3014                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3015        } else if (opt_arg(arg, 0, "dirstat-by-file",
3016                           &options->dirstat_percent)) {
3017                options->output_format |= DIFF_FORMAT_DIRSTAT;
3018                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3019        }
3020        else if (!strcmp(arg, "--check"))
3021                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3022        else if (!strcmp(arg, "--summary"))
3023                options->output_format |= DIFF_FORMAT_SUMMARY;
3024        else if (!strcmp(arg, "--patch-with-stat"))
3025                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3026        else if (!strcmp(arg, "--name-only"))
3027                options->output_format |= DIFF_FORMAT_NAME;
3028        else if (!strcmp(arg, "--name-status"))
3029                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3030        else if (!strcmp(arg, "-s"))
3031                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3032        else if (!prefixcmp(arg, "--stat")) {
3033                char *end;
3034                int width = options->stat_width;
3035                int name_width = options->stat_name_width;
3036                arg += 6;
3037                end = (char *)arg;
3038
3039                switch (*arg) {
3040                case '-':
3041                        if (!prefixcmp(arg, "-width="))
3042                                width = strtoul(arg + 7, &end, 10);
3043                        else if (!prefixcmp(arg, "-name-width="))
3044                                name_width = strtoul(arg + 12, &end, 10);
3045                        break;
3046                case '=':
3047                        width = strtoul(arg+1, &end, 10);
3048                        if (*end == ',')
3049                                name_width = strtoul(end+1, &end, 10);
3050                }
3051
3052                /* Important! This checks all the error cases! */
3053                if (*end)
3054                        return 0;
3055                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3056                options->stat_name_width = name_width;
3057                options->stat_width = width;
3058        }
3059
3060        /* renames options */
3061        else if (!prefixcmp(arg, "-B")) {
3062                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3063                        return -1;
3064        }
3065        else if (!prefixcmp(arg, "-M")) {
3066                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3067                        return -1;
3068                options->detect_rename = DIFF_DETECT_RENAME;
3069        }
3070        else if (!prefixcmp(arg, "-C")) {
3071                if (options->detect_rename == DIFF_DETECT_COPY)
3072                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3073                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3074                        return -1;
3075                options->detect_rename = DIFF_DETECT_COPY;
3076        }
3077        else if (!strcmp(arg, "--no-renames"))
3078                options->detect_rename = 0;
3079        else if (!strcmp(arg, "--relative"))
3080                DIFF_OPT_SET(options, RELATIVE_NAME);
3081        else if (!prefixcmp(arg, "--relative=")) {
3082                DIFF_OPT_SET(options, RELATIVE_NAME);
3083                options->prefix = arg + 11;
3084        }
3085
3086        /* xdiff options */
3087        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3088                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3089        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3090                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3091        else if (!strcmp(arg, "--ignore-space-at-eol"))
3092                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3093        else if (!strcmp(arg, "--patience"))
3094                DIFF_XDL_SET(options, PATIENCE_DIFF);
3095
3096        /* flags options */
3097        else if (!strcmp(arg, "--binary")) {
3098                options->output_format |= DIFF_FORMAT_PATCH;
3099                DIFF_OPT_SET(options, BINARY);
3100        }
3101        else if (!strcmp(arg, "--full-index"))
3102                DIFF_OPT_SET(options, FULL_INDEX);
3103        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3104                DIFF_OPT_SET(options, TEXT);
3105        else if (!strcmp(arg, "-R"))
3106                DIFF_OPT_SET(options, REVERSE_DIFF);
3107        else if (!strcmp(arg, "--find-copies-harder"))
3108                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3109        else if (!strcmp(arg, "--follow"))
3110                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3111        else if (!strcmp(arg, "--color"))
3112                DIFF_OPT_SET(options, COLOR_DIFF);
3113        else if (!prefixcmp(arg, "--color=")) {
3114                int value = git_config_colorbool(NULL, arg+8, -1);
3115                if (value == 0)
3116                        DIFF_OPT_CLR(options, COLOR_DIFF);
3117                else if (value > 0)
3118                        DIFF_OPT_SET(options, COLOR_DIFF);
3119                else
3120                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3121        }
3122        else if (!strcmp(arg, "--no-color"))
3123                DIFF_OPT_CLR(options, COLOR_DIFF);
3124        else if (!strcmp(arg, "--color-words")) {
3125                DIFF_OPT_SET(options, COLOR_DIFF);
3126                options->word_diff = DIFF_WORDS_COLOR;
3127        }
3128        else if (!prefixcmp(arg, "--color-words=")) {
3129                DIFF_OPT_SET(options, COLOR_DIFF);
3130                options->word_diff = DIFF_WORDS_COLOR;
3131                options->word_regex = arg + 14;
3132        }
3133        else if (!strcmp(arg, "--word-diff")) {
3134                if (options->word_diff == DIFF_WORDS_NONE)
3135                        options->word_diff = DIFF_WORDS_PLAIN;
3136        }
3137        else if (!prefixcmp(arg, "--word-diff=")) {
3138                const char *type = arg + 12;
3139                if (!strcmp(type, "plain"))
3140                        options->word_diff = DIFF_WORDS_PLAIN;
3141                else if (!strcmp(type, "color")) {
3142                        DIFF_OPT_SET(options, COLOR_DIFF);
3143                        options->word_diff = DIFF_WORDS_COLOR;
3144                }
3145                else if (!strcmp(type, "porcelain"))
3146                        options->word_diff = DIFF_WORDS_PORCELAIN;
3147                else if (!strcmp(type, "none"))
3148                        options->word_diff = DIFF_WORDS_NONE;
3149                else
3150                        die("bad --word-diff argument: %s", type);
3151        }
3152        else if (!prefixcmp(arg, "--word-diff-regex=")) {
3153                if (options->word_diff == DIFF_WORDS_NONE)
3154                        options->word_diff = DIFF_WORDS_PLAIN;
3155                options->word_regex = arg + 18;
3156        }
3157        else if (!strcmp(arg, "--exit-code"))
3158                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3159        else if (!strcmp(arg, "--quiet"))
3160                DIFF_OPT_SET(options, QUICK);
3161        else if (!strcmp(arg, "--ext-diff"))
3162                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3163        else if (!strcmp(arg, "--no-ext-diff"))
3164                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3165        else if (!strcmp(arg, "--textconv"))
3166                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3167        else if (!strcmp(arg, "--no-textconv"))
3168                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3169        else if (!strcmp(arg, "--ignore-submodules"))
3170                handle_ignore_submodules_arg(options, "all");
3171        else if (!prefixcmp(arg, "--ignore-submodules="))
3172                handle_ignore_submodules_arg(options, arg + 20);
3173        else if (!strcmp(arg, "--submodule"))
3174                DIFF_OPT_SET(options, SUBMODULE_LOG);
3175        else if (!prefixcmp(arg, "--submodule=")) {
3176                if (!strcmp(arg + 12, "log"))
3177                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3178        }
3179
3180        /* misc options */
3181        else if (!strcmp(arg, "-z"))
3182                options->line_termination = 0;
3183        else if (!prefixcmp(arg, "-l"))
3184                options->rename_limit = strtoul(arg+2, NULL, 10);
3185        else if (!prefixcmp(arg, "-S"))
3186                options->pickaxe = arg + 2;
3187        else if (!strcmp(arg, "--pickaxe-all"))
3188                options->pickaxe_opts = DIFF_PICKAXE_ALL;
3189        else if (!strcmp(arg, "--pickaxe-regex"))
3190                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
3191        else if (!prefixcmp(arg, "-O"))
3192                options->orderfile = arg + 2;
3193        else if (!prefixcmp(arg, "--diff-filter="))
3194                options->filter = arg + 14;
3195        else if (!strcmp(arg, "--abbrev"))
3196                options->abbrev = DEFAULT_ABBREV;
3197        else if (!prefixcmp(arg, "--abbrev=")) {
3198                options->abbrev = strtoul(arg + 9, NULL, 10);
3199                if (options->abbrev < MINIMUM_ABBREV)
3200                        options->abbrev = MINIMUM_ABBREV;
3201                else if (40 < options->abbrev)
3202                        options->abbrev = 40;
3203        }
3204        else if (!prefixcmp(arg, "--src-prefix="))
3205                options->a_prefix = arg + 13;
3206        else if (!prefixcmp(arg, "--dst-prefix="))
3207                options->b_prefix = arg + 13;
3208        else if (!strcmp(arg, "--no-prefix"))
3209                options->a_prefix = options->b_prefix = "";
3210        else if (opt_arg(arg, '\0', "inter-hunk-context",
3211                         &options->interhunkcontext))
3212                ;
3213        else if (!prefixcmp(arg, "--output=")) {
3214                options->file = fopen(arg + strlen("--output="), "w");
3215                if (!options->file)
3216                        die_errno("Could not open '%s'", arg + strlen("--output="));
3217                options->close_file = 1;
3218        } else
3219                return 0;
3220        return 1;
3221}
3222
3223static int parse_num(const char **cp_p)
3224{
3225        unsigned long num, scale;
3226        int ch, dot;
3227        const char *cp = *cp_p;
3228
3229        num = 0;
3230        scale = 1;
3231        dot = 0;
3232        for (;;) {
3233                ch = *cp;
3234                if ( !dot && ch == '.' ) {
3235                        scale = 1;
3236                        dot = 1;
3237                } else if ( ch == '%' ) {
3238                        scale = dot ? scale*100 : 100;
3239                        cp++;   /* % is always at the end */
3240                        break;
3241                } else if ( ch >= '0' && ch <= '9' ) {
3242                        if ( scale < 100000 ) {
3243                                scale *= 10;
3244                                num = (num*10) + (ch-'0');
3245                        }
3246                } else {
3247                        break;
3248                }
3249                cp++;
3250        }
3251        *cp_p = cp;
3252
3253        /* user says num divided by scale and we say internally that
3254         * is MAX_SCORE * num / scale.
3255         */
3256        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3257}
3258
3259static int diff_scoreopt_parse(const char *opt)
3260{
3261        int opt1, opt2, cmd;
3262
3263        if (*opt++ != '-')
3264                return -1;
3265        cmd = *opt++;
3266        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3267                return -1; /* that is not a -M, -C nor -B option */
3268
3269        opt1 = parse_num(&opt);
3270        if (cmd != 'B')
3271                opt2 = 0;
3272        else {
3273                if (*opt == 0)
3274                        opt2 = 0;
3275                else if (*opt != '/')
3276                        return -1; /* we expect -B80/99 or -B80 */
3277                else {
3278                        opt++;
3279                        opt2 = parse_num(&opt);
3280                }
3281        }
3282        if (*opt != 0)
3283                return -1;
3284        return opt1 | (opt2 << 16);
3285}
3286
3287struct diff_queue_struct diff_queued_diff;
3288
3289void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3290{
3291        if (queue->alloc <= queue->nr) {
3292                queue->alloc = alloc_nr(queue->alloc);
3293                queue->queue = xrealloc(queue->queue,
3294                                        sizeof(dp) * queue->alloc);
3295        }
3296        queue->queue[queue->nr++] = dp;
3297}
3298
3299struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3300                                 struct diff_filespec *one,
3301                                 struct diff_filespec *two)
3302{
3303        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3304        dp->one = one;
3305        dp->two = two;
3306        if (queue)
3307                diff_q(queue, dp);
3308        return dp;
3309}
3310
3311void diff_free_filepair(struct diff_filepair *p)
3312{
3313        free_filespec(p->one);
3314        free_filespec(p->two);
3315        free(p);
3316}
3317
3318/* This is different from find_unique_abbrev() in that
3319 * it stuffs the result with dots for alignment.
3320 */
3321const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3322{
3323        int abblen;
3324        const char *abbrev;
3325        if (len == 40)
3326                return sha1_to_hex(sha1);
3327
3328        abbrev = find_unique_abbrev(sha1, len);
3329        abblen = strlen(abbrev);
3330        if (abblen < 37) {
3331                static char hex[41];
3332                if (len < abblen && abblen <= len + 2)
3333                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3334                else
3335                        sprintf(hex, "%s...", abbrev);
3336                return hex;
3337        }
3338        return sha1_to_hex(sha1);
3339}
3340
3341static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3342{
3343        int line_termination = opt->line_termination;
3344        int inter_name_termination = line_termination ? '\t' : '\0';
3345        if (opt->output_prefix) {
3346                struct strbuf *msg = NULL;
3347                msg = opt->output_prefix(opt, opt->output_prefix_data);
3348                fprintf(opt->file, "%s", msg->buf);
3349        }
3350
3351        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3352                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3353                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3354                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3355        }
3356        if (p->score) {
3357                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3358                        inter_name_termination);
3359        } else {
3360                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3361        }
3362
3363        if (p->status == DIFF_STATUS_COPIED ||
3364            p->status == DIFF_STATUS_RENAMED) {
3365                const char *name_a, *name_b;
3366                name_a = p->one->path;
3367                name_b = p->two->path;
3368                strip_prefix(opt->prefix_length, &name_a, &name_b);
3369                write_name_quoted(name_a, opt->file, inter_name_termination);
3370                write_name_quoted(name_b, opt->file, line_termination);
3371        } else {
3372                const char *name_a, *name_b;
3373                name_a = p->one->mode ? p->one->path : p->two->path;
3374                name_b = NULL;
3375                strip_prefix(opt->prefix_length, &name_a, &name_b);
3376                write_name_quoted(name_a, opt->file, line_termination);
3377        }
3378}
3379
3380int diff_unmodified_pair(struct diff_filepair *p)
3381{
3382        /* This function is written stricter than necessary to support
3383         * the currently implemented transformers, but the idea is to
3384         * let transformers to produce diff_filepairs any way they want,
3385         * and filter and clean them up here before producing the output.
3386         */
3387        struct diff_filespec *one = p->one, *two = p->two;
3388
3389        if (DIFF_PAIR_UNMERGED(p))
3390                return 0; /* unmerged is interesting */
3391
3392        /* deletion, addition, mode or type change
3393         * and rename are all interesting.
3394         */
3395        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3396            DIFF_PAIR_MODE_CHANGED(p) ||
3397            strcmp(one->path, two->path))
3398                return 0;
3399
3400        /* both are valid and point at the same path.  that is, we are
3401         * dealing with a change.
3402         */
3403        if (one->sha1_valid && two->sha1_valid &&
3404            !hashcmp(one->sha1, two->sha1) &&
3405            !one->dirty_submodule && !two->dirty_submodule)
3406                return 1; /* no change */
3407        if (!one->sha1_valid && !two->sha1_valid)
3408                return 1; /* both look at the same file on the filesystem. */
3409        return 0;
3410}
3411
3412static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3413{
3414        if (diff_unmodified_pair(p))
3415                return;
3416
3417        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3418            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3419                return; /* no tree diffs in patch format */
3420
3421        run_diff(p, o);
3422}
3423
3424static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3425                            struct diffstat_t *diffstat)
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_diffstat(p, o, diffstat);
3435}
3436
3437static void diff_flush_checkdiff(struct diff_filepair *p,
3438                struct diff_options *o)
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_checkdiff(p, o);
3448}
3449
3450int diff_queue_is_empty(void)
3451{
3452        struct diff_queue_struct *q = &diff_queued_diff;
3453        int i;
3454        for (i = 0; i < q->nr; i++)
3455                if (!diff_unmodified_pair(q->queue[i]))
3456                        return 0;
3457        return 1;
3458}
3459
3460#if DIFF_DEBUG
3461void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3462{
3463        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3464                x, one ? one : "",
3465                s->path,
3466                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3467                s->mode,
3468                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3469        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3470                x, one ? one : "",
3471                s->size, s->xfrm_flags);
3472}
3473
3474void diff_debug_filepair(const struct diff_filepair *p, int i)
3475{
3476        diff_debug_filespec(p->one, i, "one");
3477        diff_debug_filespec(p->two, i, "two");
3478        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3479                p->score, p->status ? p->status : '?',
3480                p->one->rename_used, p->broken_pair);
3481}
3482
3483void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3484{
3485        int i;
3486        if (msg)
3487                fprintf(stderr, "%s\n", msg);
3488        fprintf(stderr, "q->nr = %d\n", q->nr);
3489        for (i = 0; i < q->nr; i++) {
3490                struct diff_filepair *p = q->queue[i];
3491                diff_debug_filepair(p, i);
3492        }
3493}
3494#endif
3495
3496static void diff_resolve_rename_copy(void)
3497{
3498        int i;
3499        struct diff_filepair *p;
3500        struct diff_queue_struct *q = &diff_queued_diff;
3501
3502        diff_debug_queue("resolve-rename-copy", q);
3503
3504        for (i = 0; i < q->nr; i++) {
3505                p = q->queue[i];
3506                p->status = 0; /* undecided */
3507                if (DIFF_PAIR_UNMERGED(p))
3508                        p->status = DIFF_STATUS_UNMERGED;
3509                else if (!DIFF_FILE_VALID(p->one))
3510                        p->status = DIFF_STATUS_ADDED;
3511                else if (!DIFF_FILE_VALID(p->two))
3512                        p->status = DIFF_STATUS_DELETED;
3513                else if (DIFF_PAIR_TYPE_CHANGED(p))
3514                        p->status = DIFF_STATUS_TYPE_CHANGED;
3515
3516                /* from this point on, we are dealing with a pair
3517                 * whose both sides are valid and of the same type, i.e.
3518                 * either in-place edit or rename/copy edit.
3519                 */
3520                else if (DIFF_PAIR_RENAME(p)) {
3521                        /*
3522                         * A rename might have re-connected a broken
3523                         * pair up, causing the pathnames to be the
3524                         * same again. If so, that's not a rename at
3525                         * all, just a modification..
3526                         *
3527                         * Otherwise, see if this source was used for
3528                         * multiple renames, in which case we decrement
3529                         * the count, and call it a copy.
3530                         */
3531                        if (!strcmp(p->one->path, p->two->path))
3532                                p->status = DIFF_STATUS_MODIFIED;
3533                        else if (--p->one->rename_used > 0)
3534                                p->status = DIFF_STATUS_COPIED;
3535                        else
3536                                p->status = DIFF_STATUS_RENAMED;
3537                }
3538                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3539                         p->one->mode != p->two->mode ||
3540                         p->one->dirty_submodule ||
3541                         p->two->dirty_submodule ||
3542                         is_null_sha1(p->one->sha1))
3543                        p->status = DIFF_STATUS_MODIFIED;
3544                else {
3545                        /* This is a "no-change" entry and should not
3546                         * happen anymore, but prepare for broken callers.
3547                         */
3548                        error("feeding unmodified %s to diffcore",
3549                              p->one->path);
3550                        p->status = DIFF_STATUS_UNKNOWN;
3551                }
3552        }
3553        diff_debug_queue("resolve-rename-copy done", q);
3554}
3555
3556static int check_pair_status(struct diff_filepair *p)
3557{
3558        switch (p->status) {
3559        case DIFF_STATUS_UNKNOWN:
3560                return 0;
3561        case 0:
3562                die("internal error in diff-resolve-rename-copy");
3563        default:
3564                return 1;
3565        }
3566}
3567
3568static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3569{
3570        int fmt = opt->output_format;
3571
3572        if (fmt & DIFF_FORMAT_CHECKDIFF)
3573                diff_flush_checkdiff(p, opt);
3574        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3575                diff_flush_raw(p, opt);
3576        else if (fmt & DIFF_FORMAT_NAME) {
3577                const char *name_a, *name_b;
3578                name_a = p->two->path;
3579                name_b = NULL;
3580                strip_prefix(opt->prefix_length, &name_a, &name_b);
3581                write_name_quoted(name_a, opt->file, opt->line_termination);
3582        }
3583}
3584
3585static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3586{
3587        if (fs->mode)
3588                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3589        else
3590                fprintf(file, " %s ", newdelete);
3591        write_name_quoted(fs->path, file, '\n');
3592}
3593
3594
3595static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3596                const char *line_prefix)
3597{
3598        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3599                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3600                        p->two->mode, show_name ? ' ' : '\n');
3601                if (show_name) {
3602                        write_name_quoted(p->two->path, file, '\n');
3603                }
3604        }
3605}
3606
3607static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3608                        const char *line_prefix)
3609{
3610        char *names = pprint_rename(p->one->path, p->two->path);
3611
3612        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3613        free(names);
3614        show_mode_change(file, p, 0, line_prefix);
3615}
3616
3617static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3618{
3619        FILE *file = opt->file;
3620        char *line_prefix = "";
3621
3622        if (opt->output_prefix) {
3623                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3624                line_prefix = buf->buf;
3625        }
3626
3627        switch(p->status) {
3628        case DIFF_STATUS_DELETED:
3629                fputs(line_prefix, file);
3630                show_file_mode_name(file, "delete", p->one);
3631                break;
3632        case DIFF_STATUS_ADDED:
3633                fputs(line_prefix, file);
3634                show_file_mode_name(file, "create", p->two);
3635                break;
3636        case DIFF_STATUS_COPIED:
3637                fputs(line_prefix, file);
3638                show_rename_copy(file, "copy", p, line_prefix);
3639                break;
3640        case DIFF_STATUS_RENAMED:
3641                fputs(line_prefix, file);
3642                show_rename_copy(file, "rename", p, line_prefix);
3643                break;
3644        default:
3645                if (p->score) {
3646                        fprintf(file, "%s rewrite ", line_prefix);
3647                        write_name_quoted(p->two->path, file, ' ');
3648                        fprintf(file, "(%d%%)\n", similarity_index(p));
3649                }
3650                show_mode_change(file, p, !p->score, line_prefix);
3651                break;
3652        }
3653}
3654
3655struct patch_id_t {
3656        git_SHA_CTX *ctx;
3657        int patchlen;
3658};
3659
3660static int remove_space(char *line, int len)
3661{
3662        int i;
3663        char *dst = line;
3664        unsigned char c;
3665
3666        for (i = 0; i < len; i++)
3667                if (!isspace((c = line[i])))
3668                        *dst++ = c;
3669
3670        return dst - line;
3671}
3672
3673static void patch_id_consume(void *priv, char *line, unsigned long len)
3674{
3675        struct patch_id_t *data = priv;
3676        int new_len;
3677
3678        /* Ignore line numbers when computing the SHA1 of the patch */
3679        if (!prefixcmp(line, "@@ -"))
3680                return;
3681
3682        new_len = remove_space(line, len);
3683
3684        git_SHA1_Update(data->ctx, line, new_len);
3685        data->patchlen += new_len;
3686}
3687
3688/* returns 0 upon success, and writes result into sha1 */
3689static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3690{
3691        struct diff_queue_struct *q = &diff_queued_diff;
3692        int i;
3693        git_SHA_CTX ctx;
3694        struct patch_id_t data;
3695        char buffer[PATH_MAX * 4 + 20];
3696
3697        git_SHA1_Init(&ctx);
3698        memset(&data, 0, sizeof(struct patch_id_t));
3699        data.ctx = &ctx;
3700
3701        for (i = 0; i < q->nr; i++) {
3702                xpparam_t xpp;
3703                xdemitconf_t xecfg;
3704                mmfile_t mf1, mf2;
3705                struct diff_filepair *p = q->queue[i];
3706                int len1, len2;
3707
3708                memset(&xpp, 0, sizeof(xpp));
3709                memset(&xecfg, 0, sizeof(xecfg));
3710                if (p->status == 0)
3711                        return error("internal diff status error");
3712                if (p->status == DIFF_STATUS_UNKNOWN)
3713                        continue;
3714                if (diff_unmodified_pair(p))
3715                        continue;
3716                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3717                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3718                        continue;
3719                if (DIFF_PAIR_UNMERGED(p))
3720                        continue;
3721
3722                diff_fill_sha1_info(p->one);
3723                diff_fill_sha1_info(p->two);
3724                if (fill_mmfile(&mf1, p->one) < 0 ||
3725                                fill_mmfile(&mf2, p->two) < 0)
3726                        return error("unable to read files to diff");
3727
3728                len1 = remove_space(p->one->path, strlen(p->one->path));
3729                len2 = remove_space(p->two->path, strlen(p->two->path));
3730                if (p->one->mode == 0)
3731                        len1 = snprintf(buffer, sizeof(buffer),
3732                                        "diff--gita/%.*sb/%.*s"
3733                                        "newfilemode%06o"
3734                                        "---/dev/null"
3735                                        "+++b/%.*s",
3736                                        len1, p->one->path,
3737                                        len2, p->two->path,
3738                                        p->two->mode,
3739                                        len2, p->two->path);
3740                else if (p->two->mode == 0)
3741                        len1 = snprintf(buffer, sizeof(buffer),
3742                                        "diff--gita/%.*sb/%.*s"
3743                                        "deletedfilemode%06o"
3744                                        "---a/%.*s"
3745                                        "+++/dev/null",
3746                                        len1, p->one->path,
3747                                        len2, p->two->path,
3748                                        p->one->mode,
3749                                        len1, p->one->path);
3750                else
3751                        len1 = snprintf(buffer, sizeof(buffer),
3752                                        "diff--gita/%.*sb/%.*s"
3753                                        "---a/%.*s"
3754                                        "+++b/%.*s",
3755                                        len1, p->one->path,
3756                                        len2, p->two->path,
3757                                        len1, p->one->path,
3758                                        len2, p->two->path);
3759                git_SHA1_Update(&ctx, buffer, len1);
3760
3761                xpp.flags = 0;
3762                xecfg.ctxlen = 3;
3763                xecfg.flags = XDL_EMIT_FUNCNAMES;
3764                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3765                              &xpp, &xecfg);
3766        }
3767
3768        git_SHA1_Final(sha1, &ctx);
3769        return 0;
3770}
3771
3772int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3773{
3774        struct diff_queue_struct *q = &diff_queued_diff;
3775        int i;
3776        int result = diff_get_patch_id(options, sha1);
3777
3778        for (i = 0; i < q->nr; i++)
3779                diff_free_filepair(q->queue[i]);
3780
3781        free(q->queue);
3782        DIFF_QUEUE_CLEAR(q);
3783
3784        return result;
3785}
3786
3787static int is_summary_empty(const struct diff_queue_struct *q)
3788{
3789        int i;
3790
3791        for (i = 0; i < q->nr; i++) {
3792                const struct diff_filepair *p = q->queue[i];
3793
3794                switch (p->status) {
3795                case DIFF_STATUS_DELETED:
3796                case DIFF_STATUS_ADDED:
3797                case DIFF_STATUS_COPIED:
3798                case DIFF_STATUS_RENAMED:
3799                        return 0;
3800                default:
3801                        if (p->score)
3802                                return 0;
3803                        if (p->one->mode && p->two->mode &&
3804                            p->one->mode != p->two->mode)
3805                                return 0;
3806                        break;
3807                }
3808        }
3809        return 1;
3810}
3811
3812void diff_flush(struct diff_options *options)
3813{
3814        struct diff_queue_struct *q = &diff_queued_diff;
3815        int i, output_format = options->output_format;
3816        int separator = 0;
3817
3818        /*
3819         * Order: raw, stat, summary, patch
3820         * or:    name/name-status/checkdiff (other bits clear)
3821         */
3822        if (!q->nr)
3823                goto free_queue;
3824
3825        if (output_format & (DIFF_FORMAT_RAW |
3826                             DIFF_FORMAT_NAME |
3827                             DIFF_FORMAT_NAME_STATUS |
3828                             DIFF_FORMAT_CHECKDIFF)) {
3829                for (i = 0; i < q->nr; i++) {
3830                        struct diff_filepair *p = q->queue[i];
3831                        if (check_pair_status(p))
3832                                flush_one_pair(p, options);
3833                }
3834                separator++;
3835        }
3836
3837        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3838                struct diffstat_t diffstat;
3839
3840                memset(&diffstat, 0, sizeof(struct diffstat_t));
3841                for (i = 0; i < q->nr; i++) {
3842                        struct diff_filepair *p = q->queue[i];
3843                        if (check_pair_status(p))
3844                                diff_flush_stat(p, options, &diffstat);
3845                }
3846                if (output_format & DIFF_FORMAT_NUMSTAT)
3847                        show_numstat(&diffstat, options);
3848                if (output_format & DIFF_FORMAT_DIFFSTAT)
3849                        show_stats(&diffstat, options);
3850                if (output_format & DIFF_FORMAT_SHORTSTAT)
3851                        show_shortstats(&diffstat, options);
3852                free_diffstat_info(&diffstat);
3853                separator++;
3854        }
3855        if (output_format & DIFF_FORMAT_DIRSTAT)
3856                show_dirstat(options);
3857
3858        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3859                for (i = 0; i < q->nr; i++) {
3860                        diff_summary(options, q->queue[i]);
3861                }
3862                separator++;
3863        }
3864
3865        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3866            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3867            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3868                /*
3869                 * run diff_flush_patch for the exit status. setting
3870                 * options->file to /dev/null should be safe, becaue we
3871                 * aren't supposed to produce any output anyway.
3872                 */
3873                if (options->close_file)
3874                        fclose(options->file);
3875                options->file = fopen("/dev/null", "w");
3876                if (!options->file)
3877                        die_errno("Could not open /dev/null");
3878                options->close_file = 1;
3879                for (i = 0; i < q->nr; i++) {
3880                        struct diff_filepair *p = q->queue[i];
3881                        if (check_pair_status(p))
3882                                diff_flush_patch(p, options);
3883                        if (options->found_changes)
3884                                break;
3885                }
3886        }
3887
3888        if (output_format & DIFF_FORMAT_PATCH) {
3889                if (separator) {
3890                        putc(options->line_termination, options->file);
3891                        if (options->stat_sep) {
3892                                /* attach patch instead of inline */
3893                                fputs(options->stat_sep, options->file);
3894                        }
3895                }
3896
3897                for (i = 0; i < q->nr; i++) {
3898                        struct diff_filepair *p = q->queue[i];
3899                        if (check_pair_status(p))
3900                                diff_flush_patch(p, options);
3901                }
3902        }
3903
3904        if (output_format & DIFF_FORMAT_CALLBACK)
3905                options->format_callback(q, options, options->format_callback_data);
3906
3907        for (i = 0; i < q->nr; i++)
3908                diff_free_filepair(q->queue[i]);
3909free_queue:
3910        free(q->queue);
3911        DIFF_QUEUE_CLEAR(q);
3912        if (options->close_file)
3913                fclose(options->file);
3914
3915        /*
3916         * Report the content-level differences with HAS_CHANGES;
3917         * diff_addremove/diff_change does not set the bit when
3918         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3919         */
3920        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3921                if (options->found_changes)
3922                        DIFF_OPT_SET(options, HAS_CHANGES);
3923                else
3924                        DIFF_OPT_CLR(options, HAS_CHANGES);
3925        }
3926}
3927
3928static void diffcore_apply_filter(const char *filter)
3929{
3930        int i;
3931        struct diff_queue_struct *q = &diff_queued_diff;
3932        struct diff_queue_struct outq;
3933        DIFF_QUEUE_CLEAR(&outq);
3934
3935        if (!filter)
3936                return;
3937
3938        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3939                int found;
3940                for (i = found = 0; !found && i < q->nr; i++) {
3941                        struct diff_filepair *p = q->queue[i];
3942                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3943                             ((p->score &&
3944                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3945                              (!p->score &&
3946                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3947                            ((p->status != DIFF_STATUS_MODIFIED) &&
3948                             strchr(filter, p->status)))
3949                                found++;
3950                }
3951                if (found)
3952                        return;
3953
3954                /* otherwise we will clear the whole queue
3955                 * by copying the empty outq at the end of this
3956                 * function, but first clear the current entries
3957                 * in the queue.
3958                 */
3959                for (i = 0; i < q->nr; i++)
3960                        diff_free_filepair(q->queue[i]);
3961        }
3962        else {
3963                /* Only the matching ones */
3964                for (i = 0; i < q->nr; i++) {
3965                        struct diff_filepair *p = q->queue[i];
3966
3967                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3968                             ((p->score &&
3969                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3970                              (!p->score &&
3971                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3972                            ((p->status != DIFF_STATUS_MODIFIED) &&
3973                             strchr(filter, p->status)))
3974                                diff_q(&outq, p);
3975                        else
3976                                diff_free_filepair(p);
3977                }
3978        }
3979        free(q->queue);
3980        *q = outq;
3981}
3982
3983/* Check whether two filespecs with the same mode and size are identical */
3984static int diff_filespec_is_identical(struct diff_filespec *one,
3985                                      struct diff_filespec *two)
3986{
3987        if (S_ISGITLINK(one->mode))
3988                return 0;
3989        if (diff_populate_filespec(one, 0))
3990                return 0;
3991        if (diff_populate_filespec(two, 0))
3992                return 0;
3993        return !memcmp(one->data, two->data, one->size);
3994}
3995
3996static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3997{
3998        int i;
3999        struct diff_queue_struct *q = &diff_queued_diff;
4000        struct diff_queue_struct outq;
4001        DIFF_QUEUE_CLEAR(&outq);
4002
4003        for (i = 0; i < q->nr; i++) {
4004                struct diff_filepair *p = q->queue[i];
4005
4006                /*
4007                 * 1. Entries that come from stat info dirtiness
4008                 *    always have both sides (iow, not create/delete),
4009                 *    one side of the object name is unknown, with
4010                 *    the same mode and size.  Keep the ones that
4011                 *    do not match these criteria.  They have real
4012                 *    differences.
4013                 *
4014                 * 2. At this point, the file is known to be modified,
4015                 *    with the same mode and size, and the object
4016                 *    name of one side is unknown.  Need to inspect
4017                 *    the identical contents.
4018                 */
4019                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4020                    !DIFF_FILE_VALID(p->two) ||
4021                    (p->one->sha1_valid && p->two->sha1_valid) ||
4022                    (p->one->mode != p->two->mode) ||
4023                    diff_populate_filespec(p->one, 1) ||
4024                    diff_populate_filespec(p->two, 1) ||
4025                    (p->one->size != p->two->size) ||
4026                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4027                        diff_q(&outq, p);
4028                else {
4029                        /*
4030                         * The caller can subtract 1 from skip_stat_unmatch
4031                         * to determine how many paths were dirty only
4032                         * due to stat info mismatch.
4033                         */
4034                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4035                                diffopt->skip_stat_unmatch++;
4036                        diff_free_filepair(p);
4037                }
4038        }
4039        free(q->queue);
4040        *q = outq;
4041}
4042
4043static int diffnamecmp(const void *a_, const void *b_)
4044{
4045        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4046        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4047        const char *name_a, *name_b;
4048
4049        name_a = a->one ? a->one->path : a->two->path;
4050        name_b = b->one ? b->one->path : b->two->path;
4051        return strcmp(name_a, name_b);
4052}
4053
4054void diffcore_fix_diff_index(struct diff_options *options)
4055{
4056        struct diff_queue_struct *q = &diff_queued_diff;
4057        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4058}
4059
4060void diffcore_std(struct diff_options *options)
4061{
4062        /* We never run this function more than one time, because the
4063         * rename/copy detection logic can only run once.
4064         */
4065        if (diff_queued_diff.run)
4066                return;
4067
4068        if (options->skip_stat_unmatch)
4069                diffcore_skip_stat_unmatch(options);
4070        if (options->break_opt != -1)
4071                diffcore_break(options->break_opt);
4072        if (options->detect_rename)
4073                diffcore_rename(options);
4074        if (options->break_opt != -1)
4075                diffcore_merge_broken();
4076        if (options->pickaxe)
4077                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
4078        if (options->orderfile)
4079                diffcore_order(options->orderfile);
4080        diff_resolve_rename_copy();
4081        diffcore_apply_filter(options->filter);
4082
4083        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4084                DIFF_OPT_SET(options, HAS_CHANGES);
4085        else
4086                DIFF_OPT_CLR(options, HAS_CHANGES);
4087
4088        diff_queued_diff.run = 1;
4089}
4090
4091int diff_result_code(struct diff_options *opt, int status)
4092{
4093        int result = 0;
4094        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4095            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4096                return status;
4097        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4098            DIFF_OPT_TST(opt, HAS_CHANGES))
4099                result |= 01;
4100        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4101            DIFF_OPT_TST(opt, CHECK_FAILED))
4102                result |= 02;
4103        return result;
4104}
4105
4106void diff_addremove(struct diff_options *options,
4107                    int addremove, unsigned mode,
4108                    const unsigned char *sha1,
4109                    const char *concatpath, unsigned dirty_submodule)
4110{
4111        struct diff_filespec *one, *two;
4112
4113        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
4114                return;
4115
4116        /* This may look odd, but it is a preparation for
4117         * feeding "there are unchanged files which should
4118         * not produce diffs, but when you are doing copy
4119         * detection you would need them, so here they are"
4120         * entries to the diff-core.  They will be prefixed
4121         * with something like '=' or '*' (I haven't decided
4122         * which but should not make any difference).
4123         * Feeding the same new and old to diff_change()
4124         * also has the same effect.
4125         * Before the final output happens, they are pruned after
4126         * merged into rename/copy pairs as appropriate.
4127         */
4128        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4129                addremove = (addremove == '+' ? '-' :
4130                             addremove == '-' ? '+' : addremove);
4131
4132        if (options->prefix &&
4133            strncmp(concatpath, options->prefix, options->prefix_length))
4134                return;
4135
4136        one = alloc_filespec(concatpath);
4137        two = alloc_filespec(concatpath);
4138
4139        if (addremove != '+')
4140                fill_filespec(one, sha1, mode);
4141        if (addremove != '-') {
4142                fill_filespec(two, sha1, mode);
4143                two->dirty_submodule = dirty_submodule;
4144        }
4145
4146        diff_queue(&diff_queued_diff, one, two);
4147        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4148                DIFF_OPT_SET(options, HAS_CHANGES);
4149}
4150
4151void diff_change(struct diff_options *options,
4152                 unsigned old_mode, unsigned new_mode,
4153                 const unsigned char *old_sha1,
4154                 const unsigned char *new_sha1,
4155                 const char *concatpath,
4156                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4157{
4158        struct diff_filespec *one, *two;
4159
4160        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
4161                        && S_ISGITLINK(new_mode))
4162                return;
4163
4164        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4165                unsigned tmp;
4166                const unsigned char *tmp_c;
4167                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4168                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4169                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4170                        new_dirty_submodule = tmp;
4171        }
4172
4173        if (options->prefix &&
4174            strncmp(concatpath, options->prefix, options->prefix_length))
4175                return;
4176
4177        one = alloc_filespec(concatpath);
4178        two = alloc_filespec(concatpath);
4179        fill_filespec(one, old_sha1, old_mode);
4180        fill_filespec(two, new_sha1, new_mode);
4181        one->dirty_submodule = old_dirty_submodule;
4182        two->dirty_submodule = new_dirty_submodule;
4183
4184        diff_queue(&diff_queued_diff, one, two);
4185        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4186                DIFF_OPT_SET(options, HAS_CHANGES);
4187}
4188
4189void diff_unmerge(struct diff_options *options,
4190                  const char *path,
4191                  unsigned mode, const unsigned char *sha1)
4192{
4193        struct diff_filespec *one, *two;
4194
4195        if (options->prefix &&
4196            strncmp(path, options->prefix, options->prefix_length))
4197                return;
4198
4199        one = alloc_filespec(path);
4200        two = alloc_filespec(path);
4201        fill_filespec(one, sha1, mode);
4202        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4203}
4204
4205static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4206                size_t *outsize)
4207{
4208        struct diff_tempfile *temp;
4209        const char *argv[3];
4210        const char **arg = argv;
4211        struct child_process child;
4212        struct strbuf buf = STRBUF_INIT;
4213        int err = 0;
4214
4215        temp = prepare_temp_file(spec->path, spec);
4216        *arg++ = pgm;
4217        *arg++ = temp->name;
4218        *arg = NULL;
4219
4220        memset(&child, 0, sizeof(child));
4221        child.use_shell = 1;
4222        child.argv = argv;
4223        child.out = -1;
4224        if (start_command(&child)) {
4225                remove_tempfile();
4226                return NULL;
4227        }
4228
4229        if (strbuf_read(&buf, child.out, 0) < 0)
4230                err = error("error reading from textconv command '%s'", pgm);
4231        close(child.out);
4232
4233        if (finish_command(&child) || err) {
4234                strbuf_release(&buf);
4235                remove_tempfile();
4236                return NULL;
4237        }
4238        remove_tempfile();
4239
4240        return strbuf_detach(&buf, outsize);
4241}
4242
4243size_t fill_textconv(struct userdiff_driver *driver,
4244                     struct diff_filespec *df,
4245                     char **outbuf)
4246{
4247        size_t size;
4248
4249        if (!driver || !driver->textconv) {
4250                if (!DIFF_FILE_VALID(df)) {
4251                        *outbuf = "";
4252                        return 0;
4253                }
4254                if (diff_populate_filespec(df, 0))
4255                        die("unable to read files to diff");
4256                *outbuf = df->data;
4257                return df->size;
4258        }
4259
4260        if (driver->textconv_cache) {
4261                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4262                                          &size);
4263                if (*outbuf)
4264                        return size;
4265        }
4266
4267        *outbuf = run_textconv(driver->textconv, df, &size);
4268        if (!*outbuf)
4269                die("unable to read files to diff");
4270
4271        if (driver->textconv_cache) {
4272                /* ignore errors, as we might be in a readonly repository */
4273                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4274                                size);
4275                /*
4276                 * we could save up changes and flush them all at the end,
4277                 * but we would need an extra call after all diffing is done.
4278                 * Since generating a cache entry is the slow path anyway,
4279                 * this extra overhead probably isn't a big deal.
4280                 */
4281                notes_cache_write(driver->textconv_cache);
4282        }
4283
4284        return size;
4285}