diff.con commit diff: avoid repeated scanning while looking for funcname (c099789)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include "cache.h"
   5#include "quote.h"
   6#include "diff.h"
   7#include "diffcore.h"
   8#include "delta.h"
   9#include "xdiff-interface.h"
  10#include "color.h"
  11#include "attr.h"
  12#include "run-command.h"
  13#include "utf8.h"
  14#include "userdiff.h"
  15#include "sigchain.h"
  16#include "submodule.h"
  17#include "ll-merge.h"
  18
  19#ifdef NO_FAST_WORKING_DIRECTORY
  20#define FAST_WORKING_DIRECTORY 0
  21#else
  22#define FAST_WORKING_DIRECTORY 1
  23#endif
  24
  25static int diff_detect_rename_default;
  26static int diff_rename_limit_default = 200;
  27static int diff_suppress_blank_empty;
  28int diff_use_color_default = -1;
  29static const char *diff_word_regex_cfg;
  30static const char *external_diff_cmd_cfg;
  31int diff_auto_refresh_index = 1;
  32static int diff_mnemonic_prefix;
  33static int diff_no_prefix;
  34
  35static char diff_colors[][COLOR_MAXLEN] = {
  36        GIT_COLOR_RESET,
  37        GIT_COLOR_NORMAL,       /* PLAIN */
  38        GIT_COLOR_BOLD,         /* METAINFO */
  39        GIT_COLOR_CYAN,         /* FRAGINFO */
  40        GIT_COLOR_RED,          /* OLD */
  41        GIT_COLOR_GREEN,        /* NEW */
  42        GIT_COLOR_YELLOW,       /* COMMIT */
  43        GIT_COLOR_BG_RED,       /* WHITESPACE */
  44        GIT_COLOR_NORMAL,       /* FUNCINFO */
  45};
  46
  47static int parse_diff_color_slot(const char *var, int ofs)
  48{
  49        if (!strcasecmp(var+ofs, "plain"))
  50                return DIFF_PLAIN;
  51        if (!strcasecmp(var+ofs, "meta"))
  52                return DIFF_METAINFO;
  53        if (!strcasecmp(var+ofs, "frag"))
  54                return DIFF_FRAGINFO;
  55        if (!strcasecmp(var+ofs, "old"))
  56                return DIFF_FILE_OLD;
  57        if (!strcasecmp(var+ofs, "new"))
  58                return DIFF_FILE_NEW;
  59        if (!strcasecmp(var+ofs, "commit"))
  60                return DIFF_COMMIT;
  61        if (!strcasecmp(var+ofs, "whitespace"))
  62                return DIFF_WHITESPACE;
  63        if (!strcasecmp(var+ofs, "func"))
  64                return DIFF_FUNCINFO;
  65        return -1;
  66}
  67
  68static int git_config_rename(const char *var, const char *value)
  69{
  70        if (!value)
  71                return DIFF_DETECT_RENAME;
  72        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  73                return  DIFF_DETECT_COPY;
  74        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  75}
  76
  77/*
  78 * These are to give UI layer defaults.
  79 * The core-level commands such as git-diff-files should
  80 * never be affected by the setting of diff.renames
  81 * the user happens to have in the configuration file.
  82 */
  83int git_diff_ui_config(const char *var, const char *value, void *cb)
  84{
  85        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  86                diff_use_color_default = git_config_colorbool(var, value, -1);
  87                return 0;
  88        }
  89        if (!strcmp(var, "diff.renames")) {
  90                diff_detect_rename_default = git_config_rename(var, value);
  91                return 0;
  92        }
  93        if (!strcmp(var, "diff.autorefreshindex")) {
  94                diff_auto_refresh_index = git_config_bool(var, value);
  95                return 0;
  96        }
  97        if (!strcmp(var, "diff.mnemonicprefix")) {
  98                diff_mnemonic_prefix = git_config_bool(var, value);
  99                return 0;
 100        }
 101        if (!strcmp(var, "diff.noprefix")) {
 102                diff_no_prefix = git_config_bool(var, value);
 103                return 0;
 104        }
 105        if (!strcmp(var, "diff.external"))
 106                return git_config_string(&external_diff_cmd_cfg, var, value);
 107        if (!strcmp(var, "diff.wordregex"))
 108                return git_config_string(&diff_word_regex_cfg, var, value);
 109
 110        return git_diff_basic_config(var, value, cb);
 111}
 112
 113int git_diff_basic_config(const char *var, const char *value, void *cb)
 114{
 115        if (!strcmp(var, "diff.renamelimit")) {
 116                diff_rename_limit_default = git_config_int(var, value);
 117                return 0;
 118        }
 119
 120        switch (userdiff_config(var, value)) {
 121                case 0: break;
 122                case -1: return -1;
 123                default: return 0;
 124        }
 125
 126        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 127                int slot = parse_diff_color_slot(var, 11);
 128                if (slot < 0)
 129                        return 0;
 130                if (!value)
 131                        return config_error_nonbool(var);
 132                color_parse(value, var, diff_colors[slot]);
 133                return 0;
 134        }
 135
 136        /* like GNU diff's --suppress-blank-empty option  */
 137        if (!strcmp(var, "diff.suppressblankempty") ||
 138                        /* for backwards compatibility */
 139                        !strcmp(var, "diff.suppress-blank-empty")) {
 140                diff_suppress_blank_empty = git_config_bool(var, value);
 141                return 0;
 142        }
 143
 144        return git_color_default_config(var, value, cb);
 145}
 146
 147static char *quote_two(const char *one, const char *two)
 148{
 149        int need_one = quote_c_style(one, NULL, NULL, 1);
 150        int need_two = quote_c_style(two, NULL, NULL, 1);
 151        struct strbuf res = STRBUF_INIT;
 152
 153        if (need_one + need_two) {
 154                strbuf_addch(&res, '"');
 155                quote_c_style(one, &res, NULL, 1);
 156                quote_c_style(two, &res, NULL, 1);
 157                strbuf_addch(&res, '"');
 158        } else {
 159                strbuf_addstr(&res, one);
 160                strbuf_addstr(&res, two);
 161        }
 162        return strbuf_detach(&res, NULL);
 163}
 164
 165static const char *external_diff(void)
 166{
 167        static const char *external_diff_cmd = NULL;
 168        static int done_preparing = 0;
 169
 170        if (done_preparing)
 171                return external_diff_cmd;
 172        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 173        if (!external_diff_cmd)
 174                external_diff_cmd = external_diff_cmd_cfg;
 175        done_preparing = 1;
 176        return external_diff_cmd;
 177}
 178
 179static struct diff_tempfile {
 180        const char *name; /* filename external diff should read from */
 181        char hex[41];
 182        char mode[10];
 183        char tmp_path[PATH_MAX];
 184} diff_temp[2];
 185
 186typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 187
 188struct emit_callback {
 189        int color_diff;
 190        unsigned ws_rule;
 191        int blank_at_eof_in_preimage;
 192        int blank_at_eof_in_postimage;
 193        int lno_in_preimage;
 194        int lno_in_postimage;
 195        sane_truncate_fn truncate;
 196        const char **label_path;
 197        struct diff_words_data *diff_words;
 198        struct diff_options *opt;
 199        int *found_changesp;
 200        struct strbuf *header;
 201};
 202
 203static int count_lines(const char *data, int size)
 204{
 205        int count, ch, completely_empty = 1, nl_just_seen = 0;
 206        count = 0;
 207        while (0 < size--) {
 208                ch = *data++;
 209                if (ch == '\n') {
 210                        count++;
 211                        nl_just_seen = 1;
 212                        completely_empty = 0;
 213                }
 214                else {
 215                        nl_just_seen = 0;
 216                        completely_empty = 0;
 217                }
 218        }
 219        if (completely_empty)
 220                return 0;
 221        if (!nl_just_seen)
 222                count++; /* no trailing newline */
 223        return count;
 224}
 225
 226static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 227{
 228        if (!DIFF_FILE_VALID(one)) {
 229                mf->ptr = (char *)""; /* does not matter */
 230                mf->size = 0;
 231                return 0;
 232        }
 233        else if (diff_populate_filespec(one, 0))
 234                return -1;
 235
 236        mf->ptr = one->data;
 237        mf->size = one->size;
 238        return 0;
 239}
 240
 241static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 242{
 243        char *ptr = mf->ptr;
 244        long size = mf->size;
 245        int cnt = 0;
 246
 247        if (!size)
 248                return cnt;
 249        ptr += size - 1; /* pointing at the very end */
 250        if (*ptr != '\n')
 251                ; /* incomplete line */
 252        else
 253                ptr--; /* skip the last LF */
 254        while (mf->ptr < ptr) {
 255                char *prev_eol;
 256                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 257                        if (*prev_eol == '\n')
 258                                break;
 259                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 260                        break;
 261                cnt++;
 262                ptr = prev_eol - 1;
 263        }
 264        return cnt;
 265}
 266
 267static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 268                               struct emit_callback *ecbdata)
 269{
 270        int l1, l2, at;
 271        unsigned ws_rule = ecbdata->ws_rule;
 272        l1 = count_trailing_blank(mf1, ws_rule);
 273        l2 = count_trailing_blank(mf2, ws_rule);
 274        if (l2 <= l1) {
 275                ecbdata->blank_at_eof_in_preimage = 0;
 276                ecbdata->blank_at_eof_in_postimage = 0;
 277                return;
 278        }
 279        at = count_lines(mf1->ptr, mf1->size);
 280        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 281
 282        at = count_lines(mf2->ptr, mf2->size);
 283        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 284}
 285
 286static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 287                        int first, const char *line, int len)
 288{
 289        int has_trailing_newline, has_trailing_carriage_return;
 290        int nofirst;
 291        FILE *file = o->file;
 292
 293        if (o->output_prefix) {
 294                struct strbuf *msg = NULL;
 295                msg = o->output_prefix(o, o->output_prefix_data);
 296                assert(msg);
 297                fwrite(msg->buf, msg->len, 1, file);
 298        }
 299
 300        if (len == 0) {
 301                has_trailing_newline = (first == '\n');
 302                has_trailing_carriage_return = (!has_trailing_newline &&
 303                                                (first == '\r'));
 304                nofirst = has_trailing_newline || has_trailing_carriage_return;
 305        } else {
 306                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 307                if (has_trailing_newline)
 308                        len--;
 309                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 310                if (has_trailing_carriage_return)
 311                        len--;
 312                nofirst = 0;
 313        }
 314
 315        if (len || !nofirst) {
 316                fputs(set, file);
 317                if (!nofirst)
 318                        fputc(first, file);
 319                fwrite(line, len, 1, file);
 320                fputs(reset, file);
 321        }
 322        if (has_trailing_carriage_return)
 323                fputc('\r', file);
 324        if (has_trailing_newline)
 325                fputc('\n', file);
 326}
 327
 328static void emit_line(struct diff_options *o, const char *set, const char *reset,
 329                      const char *line, int len)
 330{
 331        emit_line_0(o, set, reset, line[0], line+1, len-1);
 332}
 333
 334static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 335{
 336        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 337              ecbdata->blank_at_eof_in_preimage &&
 338              ecbdata->blank_at_eof_in_postimage &&
 339              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 340              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 341                return 0;
 342        return ws_blank_line(line, len, ecbdata->ws_rule);
 343}
 344
 345static void emit_add_line(const char *reset,
 346                          struct emit_callback *ecbdata,
 347                          const char *line, int len)
 348{
 349        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 350        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 351
 352        if (!*ws)
 353                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 354        else if (new_blank_line_at_eof(ecbdata, line, len))
 355                /* Blank line at EOF - paint '+' as well */
 356                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 357        else {
 358                /* Emit just the prefix, then the rest. */
 359                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 360                ws_check_emit(line, len, ecbdata->ws_rule,
 361                              ecbdata->opt->file, set, reset, ws);
 362        }
 363}
 364
 365static void emit_hunk_header(struct emit_callback *ecbdata,
 366                             const char *line, int len)
 367{
 368        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 369        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 370        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 371        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 372        static const char atat[2] = { '@', '@' };
 373        const char *cp, *ep;
 374        struct strbuf msgbuf = STRBUF_INIT;
 375        int org_len = len;
 376        int i = 1;
 377
 378        /*
 379         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 380         * it always is at least 10 bytes long.
 381         */
 382        if (len < 10 ||
 383            memcmp(line, atat, 2) ||
 384            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 385                emit_line(ecbdata->opt, plain, reset, line, len);
 386                return;
 387        }
 388        ep += 2; /* skip over @@ */
 389
 390        /* The hunk header in fraginfo color */
 391        strbuf_add(&msgbuf, frag, strlen(frag));
 392        strbuf_add(&msgbuf, line, ep - line);
 393        strbuf_add(&msgbuf, reset, strlen(reset));
 394
 395        /*
 396         * trailing "\r\n"
 397         */
 398        for ( ; i < 3; i++)
 399                if (line[len - i] == '\r' || line[len - i] == '\n')
 400                        len--;
 401
 402        /* blank before the func header */
 403        for (cp = ep; ep - line < len; ep++)
 404                if (*ep != ' ' && *ep != '\t')
 405                        break;
 406        if (ep != cp) {
 407                strbuf_add(&msgbuf, plain, strlen(plain));
 408                strbuf_add(&msgbuf, cp, ep - cp);
 409                strbuf_add(&msgbuf, reset, strlen(reset));
 410        }
 411
 412        if (ep < line + len) {
 413                strbuf_add(&msgbuf, func, strlen(func));
 414                strbuf_add(&msgbuf, ep, line + len - ep);
 415                strbuf_add(&msgbuf, reset, strlen(reset));
 416        }
 417
 418        strbuf_add(&msgbuf, line + len, org_len - len);
 419        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 420        strbuf_release(&msgbuf);
 421}
 422
 423static struct diff_tempfile *claim_diff_tempfile(void) {
 424        int i;
 425        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 426                if (!diff_temp[i].name)
 427                        return diff_temp + i;
 428        die("BUG: diff is failing to clean up its tempfiles");
 429}
 430
 431static int remove_tempfile_installed;
 432
 433static void remove_tempfile(void)
 434{
 435        int i;
 436        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 437                if (diff_temp[i].name == diff_temp[i].tmp_path)
 438                        unlink_or_warn(diff_temp[i].name);
 439                diff_temp[i].name = NULL;
 440        }
 441}
 442
 443static void remove_tempfile_on_signal(int signo)
 444{
 445        remove_tempfile();
 446        sigchain_pop(signo);
 447        raise(signo);
 448}
 449
 450static void print_line_count(FILE *file, int count)
 451{
 452        switch (count) {
 453        case 0:
 454                fprintf(file, "0,0");
 455                break;
 456        case 1:
 457                fprintf(file, "1");
 458                break;
 459        default:
 460                fprintf(file, "1,%d", count);
 461                break;
 462        }
 463}
 464
 465static void emit_rewrite_lines(struct emit_callback *ecb,
 466                               int prefix, const char *data, int size)
 467{
 468        const char *endp = NULL;
 469        static const char *nneof = " No newline at end of file\n";
 470        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 471        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 472
 473        while (0 < size) {
 474                int len;
 475
 476                endp = memchr(data, '\n', size);
 477                len = endp ? (endp - data + 1) : size;
 478                if (prefix != '+') {
 479                        ecb->lno_in_preimage++;
 480                        emit_line_0(ecb->opt, old, reset, '-',
 481                                    data, len);
 482                } else {
 483                        ecb->lno_in_postimage++;
 484                        emit_add_line(reset, ecb, data, len);
 485                }
 486                size -= len;
 487                data += len;
 488        }
 489        if (!endp) {
 490                const char *plain = diff_get_color(ecb->color_diff,
 491                                                   DIFF_PLAIN);
 492                emit_line_0(ecb->opt, plain, reset, '\\',
 493                            nneof, strlen(nneof));
 494        }
 495}
 496
 497static void emit_rewrite_diff(const char *name_a,
 498                              const char *name_b,
 499                              struct diff_filespec *one,
 500                              struct diff_filespec *two,
 501                              struct userdiff_driver *textconv_one,
 502                              struct userdiff_driver *textconv_two,
 503                              struct diff_options *o)
 504{
 505        int lc_a, lc_b;
 506        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 507        const char *name_a_tab, *name_b_tab;
 508        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 509        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 510        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 511        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 512        const char *a_prefix, *b_prefix;
 513        char *data_one, *data_two;
 514        size_t size_one, size_two;
 515        struct emit_callback ecbdata;
 516        char *line_prefix = "";
 517        struct strbuf *msgbuf;
 518
 519        if (o && o->output_prefix) {
 520                msgbuf = o->output_prefix(o, o->output_prefix_data);
 521                line_prefix = msgbuf->buf;
 522        }
 523
 524        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 525                a_prefix = o->b_prefix;
 526                b_prefix = o->a_prefix;
 527        } else {
 528                a_prefix = o->a_prefix;
 529                b_prefix = o->b_prefix;
 530        }
 531
 532        name_a += (*name_a == '/');
 533        name_b += (*name_b == '/');
 534        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 535        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 536
 537        strbuf_reset(&a_name);
 538        strbuf_reset(&b_name);
 539        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 540        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 541
 542        size_one = fill_textconv(textconv_one, one, &data_one);
 543        size_two = fill_textconv(textconv_two, two, &data_two);
 544
 545        memset(&ecbdata, 0, sizeof(ecbdata));
 546        ecbdata.color_diff = color_diff;
 547        ecbdata.found_changesp = &o->found_changes;
 548        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 549        ecbdata.opt = o;
 550        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 551                mmfile_t mf1, mf2;
 552                mf1.ptr = (char *)data_one;
 553                mf2.ptr = (char *)data_two;
 554                mf1.size = size_one;
 555                mf2.size = size_two;
 556                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 557        }
 558        ecbdata.lno_in_preimage = 1;
 559        ecbdata.lno_in_postimage = 1;
 560
 561        lc_a = count_lines(data_one, size_one);
 562        lc_b = count_lines(data_two, size_two);
 563        fprintf(o->file,
 564                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 565                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 566                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 567                line_prefix, fraginfo);
 568        print_line_count(o->file, lc_a);
 569        fprintf(o->file, " +");
 570        print_line_count(o->file, lc_b);
 571        fprintf(o->file, " @@%s\n", reset);
 572        if (lc_a)
 573                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 574        if (lc_b)
 575                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 576        if (textconv_one)
 577                free((char *)data_one);
 578        if (textconv_two)
 579                free((char *)data_two);
 580}
 581
 582struct diff_words_buffer {
 583        mmfile_t text;
 584        long alloc;
 585        struct diff_words_orig {
 586                const char *begin, *end;
 587        } *orig;
 588        int orig_nr, orig_alloc;
 589};
 590
 591static void diff_words_append(char *line, unsigned long len,
 592                struct diff_words_buffer *buffer)
 593{
 594        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 595        line++;
 596        len--;
 597        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 598        buffer->text.size += len;
 599        buffer->text.ptr[buffer->text.size] = '\0';
 600}
 601
 602struct diff_words_style_elem
 603{
 604        const char *prefix;
 605        const char *suffix;
 606        const char *color; /* NULL; filled in by the setup code if
 607                            * color is enabled */
 608};
 609
 610struct diff_words_style
 611{
 612        enum diff_words_type type;
 613        struct diff_words_style_elem new, old, ctx;
 614        const char *newline;
 615};
 616
 617struct diff_words_style diff_words_styles[] = {
 618        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 619        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 620        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 621};
 622
 623struct diff_words_data {
 624        struct diff_words_buffer minus, plus;
 625        const char *current_plus;
 626        int last_minus;
 627        struct diff_options *opt;
 628        regex_t *word_regex;
 629        enum diff_words_type type;
 630        struct diff_words_style *style;
 631};
 632
 633static int fn_out_diff_words_write_helper(FILE *fp,
 634                                          struct diff_words_style_elem *st_el,
 635                                          const char *newline,
 636                                          size_t count, const char *buf,
 637                                          const char *line_prefix)
 638{
 639        int print = 0;
 640
 641        while (count) {
 642                char *p = memchr(buf, '\n', count);
 643                if (print)
 644                        fputs(line_prefix, fp);
 645                if (p != buf) {
 646                        if (st_el->color && fputs(st_el->color, fp) < 0)
 647                                return -1;
 648                        if (fputs(st_el->prefix, fp) < 0 ||
 649                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 650                            fputs(st_el->suffix, fp) < 0)
 651                                return -1;
 652                        if (st_el->color && *st_el->color
 653                            && fputs(GIT_COLOR_RESET, fp) < 0)
 654                                return -1;
 655                }
 656                if (!p)
 657                        return 0;
 658                if (fputs(newline, fp) < 0)
 659                        return -1;
 660                count -= p + 1 - buf;
 661                buf = p + 1;
 662                print = 1;
 663        }
 664        return 0;
 665}
 666
 667/*
 668 * '--color-words' algorithm can be described as:
 669 *
 670 *   1. collect a the minus/plus lines of a diff hunk, divided into
 671 *      minus-lines and plus-lines;
 672 *
 673 *   2. break both minus-lines and plus-lines into words and
 674 *      place them into two mmfile_t with one word for each line;
 675 *
 676 *   3. use xdiff to run diff on the two mmfile_t to get the words level diff;
 677 *
 678 * And for the common parts of the both file, we output the plus side text.
 679 * diff_words->current_plus is used to trace the current position of the plus file
 680 * which printed. diff_words->last_minus is used to trace the last minus word
 681 * printed.
 682 *
 683 * For '--graph' to work with '--color-words', we need to output the graph prefix
 684 * on each line of color words output. Generally, there are two conditions on
 685 * which we should output the prefix.
 686 *
 687 *   1. diff_words->last_minus == 0 &&
 688 *      diff_words->current_plus == diff_words->plus.text.ptr
 689 *
 690 *      that is: the plus text must start as a new line, and if there is no minus
 691 *      word printed, a graph prefix must be printed.
 692 *
 693 *   2. diff_words->current_plus > diff_words->plus.text.ptr &&
 694 *      *(diff_words->current_plus - 1) == '\n'
 695 *
 696 *      that is: a graph prefix must be printed following a '\n'
 697 */
 698static int color_words_output_graph_prefix(struct diff_words_data *diff_words)
 699{
 700        if ((diff_words->last_minus == 0 &&
 701                diff_words->current_plus == diff_words->plus.text.ptr) ||
 702                (diff_words->current_plus > diff_words->plus.text.ptr &&
 703                *(diff_words->current_plus - 1) == '\n')) {
 704                return 1;
 705        } else {
 706                return 0;
 707        }
 708}
 709
 710static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 711{
 712        struct diff_words_data *diff_words = priv;
 713        struct diff_words_style *style = diff_words->style;
 714        int minus_first, minus_len, plus_first, plus_len;
 715        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 716        struct diff_options *opt = diff_words->opt;
 717        struct strbuf *msgbuf;
 718        char *line_prefix = "";
 719
 720        if (line[0] != '@' || parse_hunk_header(line, len,
 721                        &minus_first, &minus_len, &plus_first, &plus_len))
 722                return;
 723
 724        assert(opt);
 725        if (opt->output_prefix) {
 726                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 727                line_prefix = msgbuf->buf;
 728        }
 729
 730        /* POSIX requires that first be decremented by one if len == 0... */
 731        if (minus_len) {
 732                minus_begin = diff_words->minus.orig[minus_first].begin;
 733                minus_end =
 734                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 735        } else
 736                minus_begin = minus_end =
 737                        diff_words->minus.orig[minus_first].end;
 738
 739        if (plus_len) {
 740                plus_begin = diff_words->plus.orig[plus_first].begin;
 741                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 742        } else
 743                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 744
 745        if (color_words_output_graph_prefix(diff_words)) {
 746                fputs(line_prefix, diff_words->opt->file);
 747        }
 748        if (diff_words->current_plus != plus_begin) {
 749                fn_out_diff_words_write_helper(diff_words->opt->file,
 750                                &style->ctx, style->newline,
 751                                plus_begin - diff_words->current_plus,
 752                                diff_words->current_plus, line_prefix);
 753                if (*(plus_begin - 1) == '\n')
 754                        fputs(line_prefix, diff_words->opt->file);
 755        }
 756        if (minus_begin != minus_end) {
 757                fn_out_diff_words_write_helper(diff_words->opt->file,
 758                                &style->old, style->newline,
 759                                minus_end - minus_begin, minus_begin,
 760                                line_prefix);
 761        }
 762        if (plus_begin != plus_end) {
 763                fn_out_diff_words_write_helper(diff_words->opt->file,
 764                                &style->new, style->newline,
 765                                plus_end - plus_begin, plus_begin,
 766                                line_prefix);
 767        }
 768
 769        diff_words->current_plus = plus_end;
 770        diff_words->last_minus = minus_first;
 771}
 772
 773/* This function starts looking at *begin, and returns 0 iff a word was found. */
 774static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 775                int *begin, int *end)
 776{
 777        if (word_regex && *begin < buffer->size) {
 778                regmatch_t match[1];
 779                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 780                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 781                                        '\n', match[0].rm_eo - match[0].rm_so);
 782                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 783                        *begin += match[0].rm_so;
 784                        return *begin >= *end;
 785                }
 786                return -1;
 787        }
 788
 789        /* find the next word */
 790        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 791                (*begin)++;
 792        if (*begin >= buffer->size)
 793                return -1;
 794
 795        /* find the end of the word */
 796        *end = *begin + 1;
 797        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 798                (*end)++;
 799
 800        return 0;
 801}
 802
 803/*
 804 * This function splits the words in buffer->text, stores the list with
 805 * newline separator into out, and saves the offsets of the original words
 806 * in buffer->orig.
 807 */
 808static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 809                regex_t *word_regex)
 810{
 811        int i, j;
 812        long alloc = 0;
 813
 814        out->size = 0;
 815        out->ptr = NULL;
 816
 817        /* fake an empty "0th" word */
 818        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 819        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 820        buffer->orig_nr = 1;
 821
 822        for (i = 0; i < buffer->text.size; i++) {
 823                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 824                        return;
 825
 826                /* store original boundaries */
 827                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 828                                buffer->orig_alloc);
 829                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 830                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 831                buffer->orig_nr++;
 832
 833                /* store one word */
 834                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 835                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 836                out->ptr[out->size + j - i] = '\n';
 837                out->size += j - i + 1;
 838
 839                i = j - 1;
 840        }
 841}
 842
 843/* this executes the word diff on the accumulated buffers */
 844static void diff_words_show(struct diff_words_data *diff_words)
 845{
 846        xpparam_t xpp;
 847        xdemitconf_t xecfg;
 848        mmfile_t minus, plus;
 849        struct diff_words_style *style = diff_words->style;
 850
 851        struct diff_options *opt = diff_words->opt;
 852        struct strbuf *msgbuf;
 853        char *line_prefix = "";
 854
 855        assert(opt);
 856        if (opt->output_prefix) {
 857                msgbuf = opt->output_prefix(opt, opt->output_prefix_data);
 858                line_prefix = msgbuf->buf;
 859        }
 860
 861        /* special case: only removal */
 862        if (!diff_words->plus.text.size) {
 863                fputs(line_prefix, diff_words->opt->file);
 864                fn_out_diff_words_write_helper(diff_words->opt->file,
 865                        &style->old, style->newline,
 866                        diff_words->minus.text.size,
 867                        diff_words->minus.text.ptr, line_prefix);
 868                diff_words->minus.text.size = 0;
 869                return;
 870        }
 871
 872        diff_words->current_plus = diff_words->plus.text.ptr;
 873        diff_words->last_minus = 0;
 874
 875        memset(&xpp, 0, sizeof(xpp));
 876        memset(&xecfg, 0, sizeof(xecfg));
 877        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 878        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 879        xpp.flags = 0;
 880        /* as only the hunk header will be parsed, we need a 0-context */
 881        xecfg.ctxlen = 0;
 882        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 883                      &xpp, &xecfg);
 884        free(minus.ptr);
 885        free(plus.ptr);
 886        if (diff_words->current_plus != diff_words->plus.text.ptr +
 887                        diff_words->plus.text.size) {
 888                if (color_words_output_graph_prefix(diff_words))
 889                        fputs(line_prefix, diff_words->opt->file);
 890                fn_out_diff_words_write_helper(diff_words->opt->file,
 891                        &style->ctx, style->newline,
 892                        diff_words->plus.text.ptr + diff_words->plus.text.size
 893                        - diff_words->current_plus, diff_words->current_plus,
 894                        line_prefix);
 895        }
 896        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 897}
 898
 899/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 900static void diff_words_flush(struct emit_callback *ecbdata)
 901{
 902        if (ecbdata->diff_words->minus.text.size ||
 903            ecbdata->diff_words->plus.text.size)
 904                diff_words_show(ecbdata->diff_words);
 905}
 906
 907static void free_diff_words_data(struct emit_callback *ecbdata)
 908{
 909        if (ecbdata->diff_words) {
 910                diff_words_flush(ecbdata);
 911                free (ecbdata->diff_words->minus.text.ptr);
 912                free (ecbdata->diff_words->minus.orig);
 913                free (ecbdata->diff_words->plus.text.ptr);
 914                free (ecbdata->diff_words->plus.orig);
 915                if (ecbdata->diff_words->word_regex) {
 916                        regfree(ecbdata->diff_words->word_regex);
 917                        free(ecbdata->diff_words->word_regex);
 918                }
 919                free(ecbdata->diff_words);
 920                ecbdata->diff_words = NULL;
 921        }
 922}
 923
 924const char *diff_get_color(int diff_use_color, enum color_diff ix)
 925{
 926        if (diff_use_color)
 927                return diff_colors[ix];
 928        return "";
 929}
 930
 931static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 932{
 933        const char *cp;
 934        unsigned long allot;
 935        size_t l = len;
 936
 937        if (ecb->truncate)
 938                return ecb->truncate(line, len);
 939        cp = line;
 940        allot = l;
 941        while (0 < l) {
 942                (void) utf8_width(&cp, &l);
 943                if (!cp)
 944                        break; /* truncated in the middle? */
 945        }
 946        return allot - l;
 947}
 948
 949static void find_lno(const char *line, struct emit_callback *ecbdata)
 950{
 951        const char *p;
 952        ecbdata->lno_in_preimage = 0;
 953        ecbdata->lno_in_postimage = 0;
 954        p = strchr(line, '-');
 955        if (!p)
 956                return; /* cannot happen */
 957        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 958        p = strchr(p, '+');
 959        if (!p)
 960                return; /* cannot happen */
 961        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 962}
 963
 964static void fn_out_consume(void *priv, char *line, unsigned long len)
 965{
 966        struct emit_callback *ecbdata = priv;
 967        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 968        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 969        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 970        struct diff_options *o = ecbdata->opt;
 971        char *line_prefix = "";
 972        struct strbuf *msgbuf;
 973
 974        if (o && o->output_prefix) {
 975                msgbuf = o->output_prefix(o, o->output_prefix_data);
 976                line_prefix = msgbuf->buf;
 977        }
 978
 979        if (ecbdata->header) {
 980                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 981                strbuf_reset(ecbdata->header);
 982                ecbdata->header = NULL;
 983        }
 984        *(ecbdata->found_changesp) = 1;
 985
 986        if (ecbdata->label_path[0]) {
 987                const char *name_a_tab, *name_b_tab;
 988
 989                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 990                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 991
 992                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
 993                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
 994                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
 995                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
 996                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 997        }
 998
 999        if (diff_suppress_blank_empty
1000            && len == 2 && line[0] == ' ' && line[1] == '\n') {
1001                line[0] = '\n';
1002                len = 1;
1003        }
1004
1005        if (line[0] == '@') {
1006                if (ecbdata->diff_words)
1007                        diff_words_flush(ecbdata);
1008                len = sane_truncate_line(ecbdata, line, len);
1009                find_lno(line, ecbdata);
1010                emit_hunk_header(ecbdata, line, len);
1011                if (line[len-1] != '\n')
1012                        putc('\n', ecbdata->opt->file);
1013                return;
1014        }
1015
1016        if (len < 1) {
1017                emit_line(ecbdata->opt, reset, reset, line, len);
1018                if (ecbdata->diff_words
1019                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
1020                        fputs("~\n", ecbdata->opt->file);
1021                return;
1022        }
1023
1024        if (ecbdata->diff_words) {
1025                if (line[0] == '-') {
1026                        diff_words_append(line, len,
1027                                          &ecbdata->diff_words->minus);
1028                        return;
1029                } else if (line[0] == '+') {
1030                        diff_words_append(line, len,
1031                                          &ecbdata->diff_words->plus);
1032                        return;
1033                }
1034                diff_words_flush(ecbdata);
1035                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
1036                        emit_line(ecbdata->opt, plain, reset, line, len);
1037                        fputs("~\n", ecbdata->opt->file);
1038                } else {
1039                        /* don't print the prefix character */
1040                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
1041                }
1042                return;
1043        }
1044
1045        if (line[0] != '+') {
1046                const char *color =
1047                        diff_get_color(ecbdata->color_diff,
1048                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
1049                ecbdata->lno_in_preimage++;
1050                if (line[0] == ' ')
1051                        ecbdata->lno_in_postimage++;
1052                emit_line(ecbdata->opt, color, reset, line, len);
1053        } else {
1054                ecbdata->lno_in_postimage++;
1055                emit_add_line(reset, ecbdata, line + 1, len - 1);
1056        }
1057}
1058
1059static char *pprint_rename(const char *a, const char *b)
1060{
1061        const char *old = a;
1062        const char *new = b;
1063        struct strbuf name = STRBUF_INIT;
1064        int pfx_length, sfx_length;
1065        int len_a = strlen(a);
1066        int len_b = strlen(b);
1067        int a_midlen, b_midlen;
1068        int qlen_a = quote_c_style(a, NULL, NULL, 0);
1069        int qlen_b = quote_c_style(b, NULL, NULL, 0);
1070
1071        if (qlen_a || qlen_b) {
1072                quote_c_style(a, &name, NULL, 0);
1073                strbuf_addstr(&name, " => ");
1074                quote_c_style(b, &name, NULL, 0);
1075                return strbuf_detach(&name, NULL);
1076        }
1077
1078        /* Find common prefix */
1079        pfx_length = 0;
1080        while (*old && *new && *old == *new) {
1081                if (*old == '/')
1082                        pfx_length = old - a + 1;
1083                old++;
1084                new++;
1085        }
1086
1087        /* Find common suffix */
1088        old = a + len_a;
1089        new = b + len_b;
1090        sfx_length = 0;
1091        while (a <= old && b <= new && *old == *new) {
1092                if (*old == '/')
1093                        sfx_length = len_a - (old - a);
1094                old--;
1095                new--;
1096        }
1097
1098        /*
1099         * pfx{mid-a => mid-b}sfx
1100         * {pfx-a => pfx-b}sfx
1101         * pfx{sfx-a => sfx-b}
1102         * name-a => name-b
1103         */
1104        a_midlen = len_a - pfx_length - sfx_length;
1105        b_midlen = len_b - pfx_length - sfx_length;
1106        if (a_midlen < 0)
1107                a_midlen = 0;
1108        if (b_midlen < 0)
1109                b_midlen = 0;
1110
1111        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1112        if (pfx_length + sfx_length) {
1113                strbuf_add(&name, a, pfx_length);
1114                strbuf_addch(&name, '{');
1115        }
1116        strbuf_add(&name, a + pfx_length, a_midlen);
1117        strbuf_addstr(&name, " => ");
1118        strbuf_add(&name, b + pfx_length, b_midlen);
1119        if (pfx_length + sfx_length) {
1120                strbuf_addch(&name, '}');
1121                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1122        }
1123        return strbuf_detach(&name, NULL);
1124}
1125
1126struct diffstat_t {
1127        int nr;
1128        int alloc;
1129        struct diffstat_file {
1130                char *from_name;
1131                char *name;
1132                char *print_name;
1133                unsigned is_unmerged:1;
1134                unsigned is_binary:1;
1135                unsigned is_renamed:1;
1136                uintmax_t added, deleted;
1137        } **files;
1138};
1139
1140static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1141                                          const char *name_a,
1142                                          const char *name_b)
1143{
1144        struct diffstat_file *x;
1145        x = xcalloc(sizeof (*x), 1);
1146        if (diffstat->nr == diffstat->alloc) {
1147                diffstat->alloc = alloc_nr(diffstat->alloc);
1148                diffstat->files = xrealloc(diffstat->files,
1149                                diffstat->alloc * sizeof(x));
1150        }
1151        diffstat->files[diffstat->nr++] = x;
1152        if (name_b) {
1153                x->from_name = xstrdup(name_a);
1154                x->name = xstrdup(name_b);
1155                x->is_renamed = 1;
1156        }
1157        else {
1158                x->from_name = NULL;
1159                x->name = xstrdup(name_a);
1160        }
1161        return x;
1162}
1163
1164static void diffstat_consume(void *priv, char *line, unsigned long len)
1165{
1166        struct diffstat_t *diffstat = priv;
1167        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1168
1169        if (line[0] == '+')
1170                x->added++;
1171        else if (line[0] == '-')
1172                x->deleted++;
1173}
1174
1175const char mime_boundary_leader[] = "------------";
1176
1177static int scale_linear(int it, int width, int max_change)
1178{
1179        /*
1180         * make sure that at least one '-' is printed if there were deletions,
1181         * and likewise for '+'.
1182         */
1183        if (max_change < 2)
1184                return it;
1185        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1186}
1187
1188static void show_name(FILE *file,
1189                      const char *prefix, const char *name, int len)
1190{
1191        fprintf(file, " %s%-*s |", prefix, len, name);
1192}
1193
1194static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1195{
1196        if (cnt <= 0)
1197                return;
1198        fprintf(file, "%s", set);
1199        while (cnt--)
1200                putc(ch, file);
1201        fprintf(file, "%s", reset);
1202}
1203
1204static void fill_print_name(struct diffstat_file *file)
1205{
1206        char *pname;
1207
1208        if (file->print_name)
1209                return;
1210
1211        if (!file->is_renamed) {
1212                struct strbuf buf = STRBUF_INIT;
1213                if (quote_c_style(file->name, &buf, NULL, 0)) {
1214                        pname = strbuf_detach(&buf, NULL);
1215                } else {
1216                        pname = file->name;
1217                        strbuf_release(&buf);
1218                }
1219        } else {
1220                pname = pprint_rename(file->from_name, file->name);
1221        }
1222        file->print_name = pname;
1223}
1224
1225static void show_stats(struct diffstat_t *data, struct diff_options *options)
1226{
1227        int i, len, add, del, adds = 0, dels = 0;
1228        uintmax_t max_change = 0, max_len = 0;
1229        int total_files = data->nr;
1230        int width, name_width;
1231        const char *reset, *set, *add_c, *del_c;
1232        const char *line_prefix = "";
1233        struct strbuf *msg = NULL;
1234
1235        if (data->nr == 0)
1236                return;
1237
1238        if (options->output_prefix) {
1239                msg = options->output_prefix(options, options->output_prefix_data);
1240                line_prefix = msg->buf;
1241        }
1242
1243        width = options->stat_width ? options->stat_width : 80;
1244        name_width = options->stat_name_width ? options->stat_name_width : 50;
1245
1246        /* Sanity: give at least 5 columns to the graph,
1247         * but leave at least 10 columns for the name.
1248         */
1249        if (width < 25)
1250                width = 25;
1251        if (name_width < 10)
1252                name_width = 10;
1253        else if (width < name_width + 15)
1254                name_width = width - 15;
1255
1256        /* Find the longest filename and max number of changes */
1257        reset = diff_get_color_opt(options, DIFF_RESET);
1258        set   = diff_get_color_opt(options, DIFF_PLAIN);
1259        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1260        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1261
1262        for (i = 0; i < data->nr; i++) {
1263                struct diffstat_file *file = data->files[i];
1264                uintmax_t change = file->added + file->deleted;
1265                fill_print_name(file);
1266                len = strlen(file->print_name);
1267                if (max_len < len)
1268                        max_len = len;
1269
1270                if (file->is_binary || file->is_unmerged)
1271                        continue;
1272                if (max_change < change)
1273                        max_change = change;
1274        }
1275
1276        /* Compute the width of the graph part;
1277         * 10 is for one blank at the beginning of the line plus
1278         * " | count " between the name and the graph.
1279         *
1280         * From here on, name_width is the width of the name area,
1281         * and width is the width of the graph area.
1282         */
1283        name_width = (name_width < max_len) ? name_width : max_len;
1284        if (width < (name_width + 10) + max_change)
1285                width = width - (name_width + 10);
1286        else
1287                width = max_change;
1288
1289        for (i = 0; i < data->nr; i++) {
1290                const char *prefix = "";
1291                char *name = data->files[i]->print_name;
1292                uintmax_t added = data->files[i]->added;
1293                uintmax_t deleted = data->files[i]->deleted;
1294                int name_len;
1295
1296                /*
1297                 * "scale" the filename
1298                 */
1299                len = name_width;
1300                name_len = strlen(name);
1301                if (name_width < name_len) {
1302                        char *slash;
1303                        prefix = "...";
1304                        len -= 3;
1305                        name += name_len - len;
1306                        slash = strchr(name, '/');
1307                        if (slash)
1308                                name = slash;
1309                }
1310
1311                if (data->files[i]->is_binary) {
1312                        fprintf(options->file, "%s", line_prefix);
1313                        show_name(options->file, prefix, name, len);
1314                        fprintf(options->file, "  Bin ");
1315                        fprintf(options->file, "%s%"PRIuMAX"%s",
1316                                del_c, deleted, reset);
1317                        fprintf(options->file, " -> ");
1318                        fprintf(options->file, "%s%"PRIuMAX"%s",
1319                                add_c, added, reset);
1320                        fprintf(options->file, " bytes");
1321                        fprintf(options->file, "\n");
1322                        continue;
1323                }
1324                else if (data->files[i]->is_unmerged) {
1325                        fprintf(options->file, "%s", line_prefix);
1326                        show_name(options->file, prefix, name, len);
1327                        fprintf(options->file, "  Unmerged\n");
1328                        continue;
1329                }
1330                else if (!data->files[i]->is_renamed &&
1331                         (added + deleted == 0)) {
1332                        total_files--;
1333                        continue;
1334                }
1335
1336                /*
1337                 * scale the add/delete
1338                 */
1339                add = added;
1340                del = deleted;
1341                adds += add;
1342                dels += del;
1343
1344                if (width <= max_change) {
1345                        add = scale_linear(add, width, max_change);
1346                        del = scale_linear(del, width, max_change);
1347                }
1348                fprintf(options->file, "%s", line_prefix);
1349                show_name(options->file, prefix, name, len);
1350                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1351                                added + deleted ? " " : "");
1352                show_graph(options->file, '+', add, add_c, reset);
1353                show_graph(options->file, '-', del, del_c, reset);
1354                fprintf(options->file, "\n");
1355        }
1356        fprintf(options->file, "%s", line_prefix);
1357        fprintf(options->file,
1358               " %d files changed, %d insertions(+), %d deletions(-)\n",
1359               total_files, adds, dels);
1360}
1361
1362static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1363{
1364        int i, adds = 0, dels = 0, total_files = data->nr;
1365
1366        if (data->nr == 0)
1367                return;
1368
1369        for (i = 0; i < data->nr; i++) {
1370                if (!data->files[i]->is_binary &&
1371                    !data->files[i]->is_unmerged) {
1372                        int added = data->files[i]->added;
1373                        int deleted= data->files[i]->deleted;
1374                        if (!data->files[i]->is_renamed &&
1375                            (added + deleted == 0)) {
1376                                total_files--;
1377                        } else {
1378                                adds += added;
1379                                dels += deleted;
1380                        }
1381                }
1382        }
1383        if (options->output_prefix) {
1384                struct strbuf *msg = NULL;
1385                msg = options->output_prefix(options,
1386                                options->output_prefix_data);
1387                fprintf(options->file, "%s", msg->buf);
1388        }
1389        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1390               total_files, adds, dels);
1391}
1392
1393static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1394{
1395        int i;
1396
1397        if (data->nr == 0)
1398                return;
1399
1400        for (i = 0; i < data->nr; i++) {
1401                struct diffstat_file *file = data->files[i];
1402
1403                if (options->output_prefix) {
1404                        struct strbuf *msg = NULL;
1405                        msg = options->output_prefix(options,
1406                                        options->output_prefix_data);
1407                        fprintf(options->file, "%s", msg->buf);
1408                }
1409
1410                if (file->is_binary)
1411                        fprintf(options->file, "-\t-\t");
1412                else
1413                        fprintf(options->file,
1414                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1415                                file->added, file->deleted);
1416                if (options->line_termination) {
1417                        fill_print_name(file);
1418                        if (!file->is_renamed)
1419                                write_name_quoted(file->name, options->file,
1420                                                  options->line_termination);
1421                        else {
1422                                fputs(file->print_name, options->file);
1423                                putc(options->line_termination, options->file);
1424                        }
1425                } else {
1426                        if (file->is_renamed) {
1427                                putc('\0', options->file);
1428                                write_name_quoted(file->from_name, options->file, '\0');
1429                        }
1430                        write_name_quoted(file->name, options->file, '\0');
1431                }
1432        }
1433}
1434
1435struct dirstat_file {
1436        const char *name;
1437        unsigned long changed;
1438};
1439
1440struct dirstat_dir {
1441        struct dirstat_file *files;
1442        int alloc, nr, percent, cumulative;
1443};
1444
1445static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1446                unsigned long changed, const char *base, int baselen)
1447{
1448        unsigned long this_dir = 0;
1449        unsigned int sources = 0;
1450        const char *line_prefix = "";
1451        struct strbuf *msg = NULL;
1452
1453        if (opt->output_prefix) {
1454                msg = opt->output_prefix(opt, opt->output_prefix_data);
1455                line_prefix = msg->buf;
1456        }
1457
1458        while (dir->nr) {
1459                struct dirstat_file *f = dir->files;
1460                int namelen = strlen(f->name);
1461                unsigned long this;
1462                char *slash;
1463
1464                if (namelen < baselen)
1465                        break;
1466                if (memcmp(f->name, base, baselen))
1467                        break;
1468                slash = strchr(f->name + baselen, '/');
1469                if (slash) {
1470                        int newbaselen = slash + 1 - f->name;
1471                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1472                        sources++;
1473                } else {
1474                        this = f->changed;
1475                        dir->files++;
1476                        dir->nr--;
1477                        sources += 2;
1478                }
1479                this_dir += this;
1480        }
1481
1482        /*
1483         * We don't report dirstat's for
1484         *  - the top level
1485         *  - or cases where everything came from a single directory
1486         *    under this directory (sources == 1).
1487         */
1488        if (baselen && sources != 1) {
1489                int permille = this_dir * 1000 / changed;
1490                if (permille) {
1491                        int percent = permille / 10;
1492                        if (percent >= dir->percent) {
1493                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1494                                        percent, permille % 10, baselen, base);
1495                                if (!dir->cumulative)
1496                                        return 0;
1497                        }
1498                }
1499        }
1500        return this_dir;
1501}
1502
1503static int dirstat_compare(const void *_a, const void *_b)
1504{
1505        const struct dirstat_file *a = _a;
1506        const struct dirstat_file *b = _b;
1507        return strcmp(a->name, b->name);
1508}
1509
1510static void show_dirstat(struct diff_options *options)
1511{
1512        int i;
1513        unsigned long changed;
1514        struct dirstat_dir dir;
1515        struct diff_queue_struct *q = &diff_queued_diff;
1516
1517        dir.files = NULL;
1518        dir.alloc = 0;
1519        dir.nr = 0;
1520        dir.percent = options->dirstat_percent;
1521        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1522
1523        changed = 0;
1524        for (i = 0; i < q->nr; i++) {
1525                struct diff_filepair *p = q->queue[i];
1526                const char *name;
1527                unsigned long copied, added, damage;
1528
1529                name = p->one->path ? p->one->path : p->two->path;
1530
1531                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1532                        diff_populate_filespec(p->one, 0);
1533                        diff_populate_filespec(p->two, 0);
1534                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1535                                               &copied, &added);
1536                        diff_free_filespec_data(p->one);
1537                        diff_free_filespec_data(p->two);
1538                } else if (DIFF_FILE_VALID(p->one)) {
1539                        diff_populate_filespec(p->one, 1);
1540                        copied = added = 0;
1541                        diff_free_filespec_data(p->one);
1542                } else if (DIFF_FILE_VALID(p->two)) {
1543                        diff_populate_filespec(p->two, 1);
1544                        copied = 0;
1545                        added = p->two->size;
1546                        diff_free_filespec_data(p->two);
1547                } else
1548                        continue;
1549
1550                /*
1551                 * Original minus copied is the removed material,
1552                 * added is the new material.  They are both damages
1553                 * made to the preimage. In --dirstat-by-file mode, count
1554                 * damaged files, not damaged lines. This is done by
1555                 * counting only a single damaged line per file.
1556                 */
1557                damage = (p->one->size - copied) + added;
1558                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1559                        damage = 1;
1560
1561                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1562                dir.files[dir.nr].name = name;
1563                dir.files[dir.nr].changed = damage;
1564                changed += damage;
1565                dir.nr++;
1566        }
1567
1568        /* This can happen even with many files, if everything was renames */
1569        if (!changed)
1570                return;
1571
1572        /* Show all directories with more than x% of the changes */
1573        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1574        gather_dirstat(options, &dir, changed, "", 0);
1575}
1576
1577static void free_diffstat_info(struct diffstat_t *diffstat)
1578{
1579        int i;
1580        for (i = 0; i < diffstat->nr; i++) {
1581                struct diffstat_file *f = diffstat->files[i];
1582                if (f->name != f->print_name)
1583                        free(f->print_name);
1584                free(f->name);
1585                free(f->from_name);
1586                free(f);
1587        }
1588        free(diffstat->files);
1589}
1590
1591struct checkdiff_t {
1592        const char *filename;
1593        int lineno;
1594        int conflict_marker_size;
1595        struct diff_options *o;
1596        unsigned ws_rule;
1597        unsigned status;
1598};
1599
1600static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1601{
1602        char firstchar;
1603        int cnt;
1604
1605        if (len < marker_size + 1)
1606                return 0;
1607        firstchar = line[0];
1608        switch (firstchar) {
1609        case '=': case '>': case '<': case '|':
1610                break;
1611        default:
1612                return 0;
1613        }
1614        for (cnt = 1; cnt < marker_size; cnt++)
1615                if (line[cnt] != firstchar)
1616                        return 0;
1617        /* line[1] thru line[marker_size-1] are same as firstchar */
1618        if (len < marker_size + 1 || !isspace(line[marker_size]))
1619                return 0;
1620        return 1;
1621}
1622
1623static void checkdiff_consume(void *priv, char *line, unsigned long len)
1624{
1625        struct checkdiff_t *data = priv;
1626        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1627        int marker_size = data->conflict_marker_size;
1628        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1629        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1630        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1631        char *err;
1632        char *line_prefix = "";
1633        struct strbuf *msgbuf;
1634
1635        assert(data->o);
1636        if (data->o->output_prefix) {
1637                msgbuf = data->o->output_prefix(data->o,
1638                        data->o->output_prefix_data);
1639                line_prefix = msgbuf->buf;
1640        }
1641
1642        if (line[0] == '+') {
1643                unsigned bad;
1644                data->lineno++;
1645                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1646                        data->status |= 1;
1647                        fprintf(data->o->file,
1648                                "%s%s:%d: leftover conflict marker\n",
1649                                line_prefix, data->filename, data->lineno);
1650                }
1651                bad = ws_check(line + 1, len - 1, data->ws_rule);
1652                if (!bad)
1653                        return;
1654                data->status |= bad;
1655                err = whitespace_error_string(bad);
1656                fprintf(data->o->file, "%s%s:%d: %s.\n",
1657                        line_prefix, data->filename, data->lineno, err);
1658                free(err);
1659                emit_line(data->o, set, reset, line, 1);
1660                ws_check_emit(line + 1, len - 1, data->ws_rule,
1661                              data->o->file, set, reset, ws);
1662        } else if (line[0] == ' ') {
1663                data->lineno++;
1664        } else if (line[0] == '@') {
1665                char *plus = strchr(line, '+');
1666                if (plus)
1667                        data->lineno = strtol(plus, NULL, 10) - 1;
1668                else
1669                        die("invalid diff");
1670        }
1671}
1672
1673static unsigned char *deflate_it(char *data,
1674                                 unsigned long size,
1675                                 unsigned long *result_size)
1676{
1677        int bound;
1678        unsigned char *deflated;
1679        z_stream stream;
1680
1681        memset(&stream, 0, sizeof(stream));
1682        deflateInit(&stream, zlib_compression_level);
1683        bound = deflateBound(&stream, size);
1684        deflated = xmalloc(bound);
1685        stream.next_out = deflated;
1686        stream.avail_out = bound;
1687
1688        stream.next_in = (unsigned char *)data;
1689        stream.avail_in = size;
1690        while (deflate(&stream, Z_FINISH) == Z_OK)
1691                ; /* nothing */
1692        deflateEnd(&stream);
1693        *result_size = stream.total_out;
1694        return deflated;
1695}
1696
1697static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1698{
1699        void *cp;
1700        void *delta;
1701        void *deflated;
1702        void *data;
1703        unsigned long orig_size;
1704        unsigned long delta_size;
1705        unsigned long deflate_size;
1706        unsigned long data_size;
1707
1708        /* We could do deflated delta, or we could do just deflated two,
1709         * whichever is smaller.
1710         */
1711        delta = NULL;
1712        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1713        if (one->size && two->size) {
1714                delta = diff_delta(one->ptr, one->size,
1715                                   two->ptr, two->size,
1716                                   &delta_size, deflate_size);
1717                if (delta) {
1718                        void *to_free = delta;
1719                        orig_size = delta_size;
1720                        delta = deflate_it(delta, delta_size, &delta_size);
1721                        free(to_free);
1722                }
1723        }
1724
1725        if (delta && delta_size < deflate_size) {
1726                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1727                free(deflated);
1728                data = delta;
1729                data_size = delta_size;
1730        }
1731        else {
1732                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1733                free(delta);
1734                data = deflated;
1735                data_size = deflate_size;
1736        }
1737
1738        /* emit data encoded in base85 */
1739        cp = data;
1740        while (data_size) {
1741                int bytes = (52 < data_size) ? 52 : data_size;
1742                char line[70];
1743                data_size -= bytes;
1744                if (bytes <= 26)
1745                        line[0] = bytes + 'A' - 1;
1746                else
1747                        line[0] = bytes - 26 + 'a' - 1;
1748                encode_85(line + 1, cp, bytes);
1749                cp = (char *) cp + bytes;
1750                fprintf(file, "%s", prefix);
1751                fputs(line, file);
1752                fputc('\n', file);
1753        }
1754        fprintf(file, "%s\n", prefix);
1755        free(data);
1756}
1757
1758static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1759{
1760        fprintf(file, "%sGIT binary patch\n", prefix);
1761        emit_binary_diff_body(file, one, two, prefix);
1762        emit_binary_diff_body(file, two, one, prefix);
1763}
1764
1765static void diff_filespec_load_driver(struct diff_filespec *one)
1766{
1767        if (!one->driver)
1768                one->driver = userdiff_find_by_path(one->path);
1769        if (!one->driver)
1770                one->driver = userdiff_find_by_name("default");
1771}
1772
1773int diff_filespec_is_binary(struct diff_filespec *one)
1774{
1775        if (one->is_binary == -1) {
1776                diff_filespec_load_driver(one);
1777                if (one->driver->binary != -1)
1778                        one->is_binary = one->driver->binary;
1779                else {
1780                        if (!one->data && DIFF_FILE_VALID(one))
1781                                diff_populate_filespec(one, 0);
1782                        if (one->data)
1783                                one->is_binary = buffer_is_binary(one->data,
1784                                                one->size);
1785                        if (one->is_binary == -1)
1786                                one->is_binary = 0;
1787                }
1788        }
1789        return one->is_binary;
1790}
1791
1792static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1793{
1794        diff_filespec_load_driver(one);
1795        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1796}
1797
1798static const char *userdiff_word_regex(struct diff_filespec *one)
1799{
1800        diff_filespec_load_driver(one);
1801        return one->driver->word_regex;
1802}
1803
1804void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1805{
1806        if (!options->a_prefix)
1807                options->a_prefix = a;
1808        if (!options->b_prefix)
1809                options->b_prefix = b;
1810}
1811
1812struct userdiff_driver *get_textconv(struct diff_filespec *one)
1813{
1814        if (!DIFF_FILE_VALID(one))
1815                return NULL;
1816        if (!S_ISREG(one->mode))
1817                return NULL;
1818        diff_filespec_load_driver(one);
1819        if (!one->driver->textconv)
1820                return NULL;
1821
1822        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1823                struct notes_cache *c = xmalloc(sizeof(*c));
1824                struct strbuf name = STRBUF_INIT;
1825
1826                strbuf_addf(&name, "textconv/%s", one->driver->name);
1827                notes_cache_init(c, name.buf, one->driver->textconv);
1828                one->driver->textconv_cache = c;
1829        }
1830
1831        return one->driver;
1832}
1833
1834static void builtin_diff(const char *name_a,
1835                         const char *name_b,
1836                         struct diff_filespec *one,
1837                         struct diff_filespec *two,
1838                         const char *xfrm_msg,
1839                         int must_show_header,
1840                         struct diff_options *o,
1841                         int complete_rewrite)
1842{
1843        mmfile_t mf1, mf2;
1844        const char *lbl[2];
1845        char *a_one, *b_two;
1846        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1847        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1848        const char *a_prefix, *b_prefix;
1849        struct userdiff_driver *textconv_one = NULL;
1850        struct userdiff_driver *textconv_two = NULL;
1851        struct strbuf header = STRBUF_INIT;
1852        struct strbuf *msgbuf;
1853        char *line_prefix = "";
1854
1855        if (o->output_prefix) {
1856                msgbuf = o->output_prefix(o, o->output_prefix_data);
1857                line_prefix = msgbuf->buf;
1858        }
1859
1860        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1861                        (!one->mode || S_ISGITLINK(one->mode)) &&
1862                        (!two->mode || S_ISGITLINK(two->mode))) {
1863                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1864                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1865                show_submodule_summary(o->file, one ? one->path : two->path,
1866                                one->sha1, two->sha1, two->dirty_submodule,
1867                                del, add, reset);
1868                return;
1869        }
1870
1871        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1872                textconv_one = get_textconv(one);
1873                textconv_two = get_textconv(two);
1874        }
1875
1876        diff_set_mnemonic_prefix(o, "a/", "b/");
1877        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1878                a_prefix = o->b_prefix;
1879                b_prefix = o->a_prefix;
1880        } else {
1881                a_prefix = o->a_prefix;
1882                b_prefix = o->b_prefix;
1883        }
1884
1885        /* Never use a non-valid filename anywhere if at all possible */
1886        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1887        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1888
1889        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1890        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1891        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1892        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1893        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1894        if (lbl[0][0] == '/') {
1895                /* /dev/null */
1896                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1897                if (xfrm_msg)
1898                        strbuf_addstr(&header, xfrm_msg);
1899                must_show_header = 1;
1900        }
1901        else if (lbl[1][0] == '/') {
1902                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1903                if (xfrm_msg)
1904                        strbuf_addstr(&header, xfrm_msg);
1905                must_show_header = 1;
1906        }
1907        else {
1908                if (one->mode != two->mode) {
1909                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1910                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1911                        must_show_header = 1;
1912                }
1913                if (xfrm_msg)
1914                        strbuf_addstr(&header, xfrm_msg);
1915
1916                /*
1917                 * we do not run diff between different kind
1918                 * of objects.
1919                 */
1920                if ((one->mode ^ two->mode) & S_IFMT)
1921                        goto free_ab_and_return;
1922                if (complete_rewrite &&
1923                    (textconv_one || !diff_filespec_is_binary(one)) &&
1924                    (textconv_two || !diff_filespec_is_binary(two))) {
1925                        fprintf(o->file, "%s", header.buf);
1926                        strbuf_reset(&header);
1927                        emit_rewrite_diff(name_a, name_b, one, two,
1928                                                textconv_one, textconv_two, o);
1929                        o->found_changes = 1;
1930                        goto free_ab_and_return;
1931                }
1932        }
1933
1934        if (!DIFF_OPT_TST(o, TEXT) &&
1935            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1936              (!textconv_two && diff_filespec_is_binary(two)) )) {
1937                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1938                        die("unable to read files to diff");
1939                /* Quite common confusing case */
1940                if (mf1.size == mf2.size &&
1941                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
1942                        if (must_show_header)
1943                                fprintf(o->file, "%s", header.buf);
1944                        goto free_ab_and_return;
1945                }
1946                fprintf(o->file, "%s", header.buf);
1947                strbuf_reset(&header);
1948                if (DIFF_OPT_TST(o, BINARY))
1949                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1950                else
1951                        fprintf(o->file, "%sBinary files %s and %s differ\n",
1952                                line_prefix, lbl[0], lbl[1]);
1953                o->found_changes = 1;
1954        }
1955        else {
1956                /* Crazy xdl interfaces.. */
1957                const char *diffopts = getenv("GIT_DIFF_OPTS");
1958                xpparam_t xpp;
1959                xdemitconf_t xecfg;
1960                struct emit_callback ecbdata;
1961                const struct userdiff_funcname *pe;
1962
1963                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS) || must_show_header) {
1964                        fprintf(o->file, "%s", header.buf);
1965                        strbuf_reset(&header);
1966                }
1967
1968                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1969                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1970
1971                pe = diff_funcname_pattern(one);
1972                if (!pe)
1973                        pe = diff_funcname_pattern(two);
1974
1975                memset(&xpp, 0, sizeof(xpp));
1976                memset(&xecfg, 0, sizeof(xecfg));
1977                memset(&ecbdata, 0, sizeof(ecbdata));
1978                ecbdata.label_path = lbl;
1979                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1980                ecbdata.found_changesp = &o->found_changes;
1981                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1982                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1983                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1984                ecbdata.opt = o;
1985                ecbdata.header = header.len ? &header : NULL;
1986                xpp.flags = o->xdl_opts;
1987                xecfg.ctxlen = o->context;
1988                xecfg.interhunkctxlen = o->interhunkcontext;
1989                xecfg.flags = XDL_EMIT_FUNCNAMES;
1990                if (pe)
1991                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1992                if (!diffopts)
1993                        ;
1994                else if (!prefixcmp(diffopts, "--unified="))
1995                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1996                else if (!prefixcmp(diffopts, "-u"))
1997                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1998                if (o->word_diff) {
1999                        int i;
2000
2001                        ecbdata.diff_words =
2002                                xcalloc(1, sizeof(struct diff_words_data));
2003                        ecbdata.diff_words->type = o->word_diff;
2004                        ecbdata.diff_words->opt = o;
2005                        if (!o->word_regex)
2006                                o->word_regex = userdiff_word_regex(one);
2007                        if (!o->word_regex)
2008                                o->word_regex = userdiff_word_regex(two);
2009                        if (!o->word_regex)
2010                                o->word_regex = diff_word_regex_cfg;
2011                        if (o->word_regex) {
2012                                ecbdata.diff_words->word_regex = (regex_t *)
2013                                        xmalloc(sizeof(regex_t));
2014                                if (regcomp(ecbdata.diff_words->word_regex,
2015                                                o->word_regex,
2016                                                REG_EXTENDED | REG_NEWLINE))
2017                                        die ("Invalid regular expression: %s",
2018                                                        o->word_regex);
2019                        }
2020                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
2021                                if (o->word_diff == diff_words_styles[i].type) {
2022                                        ecbdata.diff_words->style =
2023                                                &diff_words_styles[i];
2024                                        break;
2025                                }
2026                        }
2027                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
2028                                struct diff_words_style *st = ecbdata.diff_words->style;
2029                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
2030                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
2031                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
2032                        }
2033                }
2034                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
2035                              &xpp, &xecfg);
2036                if (o->word_diff)
2037                        free_diff_words_data(&ecbdata);
2038                if (textconv_one)
2039                        free(mf1.ptr);
2040                if (textconv_two)
2041                        free(mf2.ptr);
2042                xdiff_clear_find_func(&xecfg);
2043        }
2044
2045 free_ab_and_return:
2046        strbuf_release(&header);
2047        diff_free_filespec_data(one);
2048        diff_free_filespec_data(two);
2049        free(a_one);
2050        free(b_two);
2051        return;
2052}
2053
2054static void builtin_diffstat(const char *name_a, const char *name_b,
2055                             struct diff_filespec *one,
2056                             struct diff_filespec *two,
2057                             struct diffstat_t *diffstat,
2058                             struct diff_options *o,
2059                             int complete_rewrite)
2060{
2061        mmfile_t mf1, mf2;
2062        struct diffstat_file *data;
2063
2064        data = diffstat_add(diffstat, name_a, name_b);
2065
2066        if (!one || !two) {
2067                data->is_unmerged = 1;
2068                return;
2069        }
2070        if (complete_rewrite) {
2071                diff_populate_filespec(one, 0);
2072                diff_populate_filespec(two, 0);
2073                data->deleted = count_lines(one->data, one->size);
2074                data->added = count_lines(two->data, two->size);
2075                goto free_and_return;
2076        }
2077        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2078                die("unable to read files to diff");
2079
2080        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
2081                data->is_binary = 1;
2082                data->added = mf2.size;
2083                data->deleted = mf1.size;
2084        } else {
2085                /* Crazy xdl interfaces.. */
2086                xpparam_t xpp;
2087                xdemitconf_t xecfg;
2088
2089                memset(&xpp, 0, sizeof(xpp));
2090                memset(&xecfg, 0, sizeof(xecfg));
2091                xpp.flags = o->xdl_opts;
2092                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
2093                              &xpp, &xecfg);
2094        }
2095
2096 free_and_return:
2097        diff_free_filespec_data(one);
2098        diff_free_filespec_data(two);
2099}
2100
2101static void builtin_checkdiff(const char *name_a, const char *name_b,
2102                              const char *attr_path,
2103                              struct diff_filespec *one,
2104                              struct diff_filespec *two,
2105                              struct diff_options *o)
2106{
2107        mmfile_t mf1, mf2;
2108        struct checkdiff_t data;
2109
2110        if (!two)
2111                return;
2112
2113        memset(&data, 0, sizeof(data));
2114        data.filename = name_b ? name_b : name_a;
2115        data.lineno = 0;
2116        data.o = o;
2117        data.ws_rule = whitespace_rule(attr_path);
2118        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2119
2120        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2121                die("unable to read files to diff");
2122
2123        /*
2124         * All the other codepaths check both sides, but not checking
2125         * the "old" side here is deliberate.  We are checking the newly
2126         * introduced changes, and as long as the "new" side is text, we
2127         * can and should check what it introduces.
2128         */
2129        if (diff_filespec_is_binary(two))
2130                goto free_and_return;
2131        else {
2132                /* Crazy xdl interfaces.. */
2133                xpparam_t xpp;
2134                xdemitconf_t xecfg;
2135
2136                memset(&xpp, 0, sizeof(xpp));
2137                memset(&xecfg, 0, sizeof(xecfg));
2138                xecfg.ctxlen = 1; /* at least one context line */
2139                xpp.flags = 0;
2140                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2141                              &xpp, &xecfg);
2142
2143                if (data.ws_rule & WS_BLANK_AT_EOF) {
2144                        struct emit_callback ecbdata;
2145                        int blank_at_eof;
2146
2147                        ecbdata.ws_rule = data.ws_rule;
2148                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2149                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
2150
2151                        if (blank_at_eof) {
2152                                static char *err;
2153                                if (!err)
2154                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2155                                fprintf(o->file, "%s:%d: %s.\n",
2156                                        data.filename, blank_at_eof, err);
2157                                data.status = 1; /* report errors */
2158                        }
2159                }
2160        }
2161 free_and_return:
2162        diff_free_filespec_data(one);
2163        diff_free_filespec_data(two);
2164        if (data.status)
2165                DIFF_OPT_SET(o, CHECK_FAILED);
2166}
2167
2168struct diff_filespec *alloc_filespec(const char *path)
2169{
2170        int namelen = strlen(path);
2171        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2172
2173        memset(spec, 0, sizeof(*spec));
2174        spec->path = (char *)(spec + 1);
2175        memcpy(spec->path, path, namelen+1);
2176        spec->count = 1;
2177        spec->is_binary = -1;
2178        return spec;
2179}
2180
2181void free_filespec(struct diff_filespec *spec)
2182{
2183        if (!--spec->count) {
2184                diff_free_filespec_data(spec);
2185                free(spec);
2186        }
2187}
2188
2189void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2190                   unsigned short mode)
2191{
2192        if (mode) {
2193                spec->mode = canon_mode(mode);
2194                hashcpy(spec->sha1, sha1);
2195                spec->sha1_valid = !is_null_sha1(sha1);
2196        }
2197}
2198
2199/*
2200 * Given a name and sha1 pair, if the index tells us the file in
2201 * the work tree has that object contents, return true, so that
2202 * prepare_temp_file() does not have to inflate and extract.
2203 */
2204static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2205{
2206        struct cache_entry *ce;
2207        struct stat st;
2208        int pos, len;
2209
2210        /*
2211         * We do not read the cache ourselves here, because the
2212         * benchmark with my previous version that always reads cache
2213         * shows that it makes things worse for diff-tree comparing
2214         * two linux-2.6 kernel trees in an already checked out work
2215         * tree.  This is because most diff-tree comparisons deal with
2216         * only a small number of files, while reading the cache is
2217         * expensive for a large project, and its cost outweighs the
2218         * savings we get by not inflating the object to a temporary
2219         * file.  Practically, this code only helps when we are used
2220         * by diff-cache --cached, which does read the cache before
2221         * calling us.
2222         */
2223        if (!active_cache)
2224                return 0;
2225
2226        /* We want to avoid the working directory if our caller
2227         * doesn't need the data in a normal file, this system
2228         * is rather slow with its stat/open/mmap/close syscalls,
2229         * and the object is contained in a pack file.  The pack
2230         * is probably already open and will be faster to obtain
2231         * the data through than the working directory.  Loose
2232         * objects however would tend to be slower as they need
2233         * to be individually opened and inflated.
2234         */
2235        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2236                return 0;
2237
2238        len = strlen(name);
2239        pos = cache_name_pos(name, len);
2240        if (pos < 0)
2241                return 0;
2242        ce = active_cache[pos];
2243
2244        /*
2245         * This is not the sha1 we are looking for, or
2246         * unreusable because it is not a regular file.
2247         */
2248        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2249                return 0;
2250
2251        /*
2252         * If ce is marked as "assume unchanged", there is no
2253         * guarantee that work tree matches what we are looking for.
2254         */
2255        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2256                return 0;
2257
2258        /*
2259         * If ce matches the file in the work tree, we can reuse it.
2260         */
2261        if (ce_uptodate(ce) ||
2262            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2263                return 1;
2264
2265        return 0;
2266}
2267
2268static int populate_from_stdin(struct diff_filespec *s)
2269{
2270        struct strbuf buf = STRBUF_INIT;
2271        size_t size = 0;
2272
2273        if (strbuf_read(&buf, 0, 0) < 0)
2274                return error("error while reading from stdin %s",
2275                                     strerror(errno));
2276
2277        s->should_munmap = 0;
2278        s->data = strbuf_detach(&buf, &size);
2279        s->size = size;
2280        s->should_free = 1;
2281        return 0;
2282}
2283
2284static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2285{
2286        int len;
2287        char *data = xmalloc(100), *dirty = "";
2288
2289        /* Are we looking at the work tree? */
2290        if (s->dirty_submodule)
2291                dirty = "-dirty";
2292
2293        len = snprintf(data, 100,
2294                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2295        s->data = data;
2296        s->size = len;
2297        s->should_free = 1;
2298        if (size_only) {
2299                s->data = NULL;
2300                free(data);
2301        }
2302        return 0;
2303}
2304
2305/*
2306 * While doing rename detection and pickaxe operation, we may need to
2307 * grab the data for the blob (or file) for our own in-core comparison.
2308 * diff_filespec has data and size fields for this purpose.
2309 */
2310int diff_populate_filespec(struct diff_filespec *s, int size_only)
2311{
2312        int err = 0;
2313        if (!DIFF_FILE_VALID(s))
2314                die("internal error: asking to populate invalid file.");
2315        if (S_ISDIR(s->mode))
2316                return -1;
2317
2318        if (s->data)
2319                return 0;
2320
2321        if (size_only && 0 < s->size)
2322                return 0;
2323
2324        if (S_ISGITLINK(s->mode))
2325                return diff_populate_gitlink(s, size_only);
2326
2327        if (!s->sha1_valid ||
2328            reuse_worktree_file(s->path, s->sha1, 0)) {
2329                struct strbuf buf = STRBUF_INIT;
2330                struct stat st;
2331                int fd;
2332
2333                if (!strcmp(s->path, "-"))
2334                        return populate_from_stdin(s);
2335
2336                if (lstat(s->path, &st) < 0) {
2337                        if (errno == ENOENT) {
2338                        err_empty:
2339                                err = -1;
2340                        empty:
2341                                s->data = (char *)"";
2342                                s->size = 0;
2343                                return err;
2344                        }
2345                }
2346                s->size = xsize_t(st.st_size);
2347                if (!s->size)
2348                        goto empty;
2349                if (S_ISLNK(st.st_mode)) {
2350                        struct strbuf sb = STRBUF_INIT;
2351
2352                        if (strbuf_readlink(&sb, s->path, s->size))
2353                                goto err_empty;
2354                        s->size = sb.len;
2355                        s->data = strbuf_detach(&sb, NULL);
2356                        s->should_free = 1;
2357                        return 0;
2358                }
2359                if (size_only)
2360                        return 0;
2361                fd = open(s->path, O_RDONLY);
2362                if (fd < 0)
2363                        goto err_empty;
2364                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2365                close(fd);
2366                s->should_munmap = 1;
2367
2368                /*
2369                 * Convert from working tree format to canonical git format
2370                 */
2371                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2372                        size_t size = 0;
2373                        munmap(s->data, s->size);
2374                        s->should_munmap = 0;
2375                        s->data = strbuf_detach(&buf, &size);
2376                        s->size = size;
2377                        s->should_free = 1;
2378                }
2379        }
2380        else {
2381                enum object_type type;
2382                if (size_only)
2383                        type = sha1_object_info(s->sha1, &s->size);
2384                else {
2385                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2386                        s->should_free = 1;
2387                }
2388        }
2389        return 0;
2390}
2391
2392void diff_free_filespec_blob(struct diff_filespec *s)
2393{
2394        if (s->should_free)
2395                free(s->data);
2396        else if (s->should_munmap)
2397                munmap(s->data, s->size);
2398
2399        if (s->should_free || s->should_munmap) {
2400                s->should_free = s->should_munmap = 0;
2401                s->data = NULL;
2402        }
2403}
2404
2405void diff_free_filespec_data(struct diff_filespec *s)
2406{
2407        diff_free_filespec_blob(s);
2408        free(s->cnt_data);
2409        s->cnt_data = NULL;
2410}
2411
2412static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2413                           void *blob,
2414                           unsigned long size,
2415                           const unsigned char *sha1,
2416                           int mode)
2417{
2418        int fd;
2419        struct strbuf buf = STRBUF_INIT;
2420        struct strbuf template = STRBUF_INIT;
2421        char *path_dup = xstrdup(path);
2422        const char *base = basename(path_dup);
2423
2424        /* Generate "XXXXXX_basename.ext" */
2425        strbuf_addstr(&template, "XXXXXX_");
2426        strbuf_addstr(&template, base);
2427
2428        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2429                        strlen(base) + 1);
2430        if (fd < 0)
2431                die_errno("unable to create temp-file");
2432        if (convert_to_working_tree(path,
2433                        (const char *)blob, (size_t)size, &buf)) {
2434                blob = buf.buf;
2435                size = buf.len;
2436        }
2437        if (write_in_full(fd, blob, size) != size)
2438                die_errno("unable to write temp-file");
2439        close(fd);
2440        temp->name = temp->tmp_path;
2441        strcpy(temp->hex, sha1_to_hex(sha1));
2442        temp->hex[40] = 0;
2443        sprintf(temp->mode, "%06o", mode);
2444        strbuf_release(&buf);
2445        strbuf_release(&template);
2446        free(path_dup);
2447}
2448
2449static struct diff_tempfile *prepare_temp_file(const char *name,
2450                struct diff_filespec *one)
2451{
2452        struct diff_tempfile *temp = claim_diff_tempfile();
2453
2454        if (!DIFF_FILE_VALID(one)) {
2455        not_a_valid_file:
2456                /* A '-' entry produces this for file-2, and
2457                 * a '+' entry produces this for file-1.
2458                 */
2459                temp->name = "/dev/null";
2460                strcpy(temp->hex, ".");
2461                strcpy(temp->mode, ".");
2462                return temp;
2463        }
2464
2465        if (!remove_tempfile_installed) {
2466                atexit(remove_tempfile);
2467                sigchain_push_common(remove_tempfile_on_signal);
2468                remove_tempfile_installed = 1;
2469        }
2470
2471        if (!one->sha1_valid ||
2472            reuse_worktree_file(name, one->sha1, 1)) {
2473                struct stat st;
2474                if (lstat(name, &st) < 0) {
2475                        if (errno == ENOENT)
2476                                goto not_a_valid_file;
2477                        die_errno("stat(%s)", name);
2478                }
2479                if (S_ISLNK(st.st_mode)) {
2480                        struct strbuf sb = STRBUF_INIT;
2481                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2482                                die_errno("readlink(%s)", name);
2483                        prep_temp_blob(name, temp, sb.buf, sb.len,
2484                                       (one->sha1_valid ?
2485                                        one->sha1 : null_sha1),
2486                                       (one->sha1_valid ?
2487                                        one->mode : S_IFLNK));
2488                        strbuf_release(&sb);
2489                }
2490                else {
2491                        /* we can borrow from the file in the work tree */
2492                        temp->name = name;
2493                        if (!one->sha1_valid)
2494                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2495                        else
2496                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2497                        /* Even though we may sometimes borrow the
2498                         * contents from the work tree, we always want
2499                         * one->mode.  mode is trustworthy even when
2500                         * !(one->sha1_valid), as long as
2501                         * DIFF_FILE_VALID(one).
2502                         */
2503                        sprintf(temp->mode, "%06o", one->mode);
2504                }
2505                return temp;
2506        }
2507        else {
2508                if (diff_populate_filespec(one, 0))
2509                        die("cannot read data blob for %s", one->path);
2510                prep_temp_blob(name, temp, one->data, one->size,
2511                               one->sha1, one->mode);
2512        }
2513        return temp;
2514}
2515
2516/* An external diff command takes:
2517 *
2518 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2519 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2520 *
2521 */
2522static void run_external_diff(const char *pgm,
2523                              const char *name,
2524                              const char *other,
2525                              struct diff_filespec *one,
2526                              struct diff_filespec *two,
2527                              const char *xfrm_msg,
2528                              int complete_rewrite)
2529{
2530        const char *spawn_arg[10];
2531        int retval;
2532        const char **arg = &spawn_arg[0];
2533
2534        if (one && two) {
2535                struct diff_tempfile *temp_one, *temp_two;
2536                const char *othername = (other ? other : name);
2537                temp_one = prepare_temp_file(name, one);
2538                temp_two = prepare_temp_file(othername, two);
2539                *arg++ = pgm;
2540                *arg++ = name;
2541                *arg++ = temp_one->name;
2542                *arg++ = temp_one->hex;
2543                *arg++ = temp_one->mode;
2544                *arg++ = temp_two->name;
2545                *arg++ = temp_two->hex;
2546                *arg++ = temp_two->mode;
2547                if (other) {
2548                        *arg++ = other;
2549                        *arg++ = xfrm_msg;
2550                }
2551        } else {
2552                *arg++ = pgm;
2553                *arg++ = name;
2554        }
2555        *arg = NULL;
2556        fflush(NULL);
2557        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2558        remove_tempfile();
2559        if (retval) {
2560                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2561                exit(1);
2562        }
2563}
2564
2565static int similarity_index(struct diff_filepair *p)
2566{
2567        return p->score * 100 / MAX_SCORE;
2568}
2569
2570static void fill_metainfo(struct strbuf *msg,
2571                          const char *name,
2572                          const char *other,
2573                          struct diff_filespec *one,
2574                          struct diff_filespec *two,
2575                          struct diff_options *o,
2576                          struct diff_filepair *p,
2577                          int *must_show_header,
2578                          int use_color)
2579{
2580        const char *set = diff_get_color(use_color, DIFF_METAINFO);
2581        const char *reset = diff_get_color(use_color, DIFF_RESET);
2582        struct strbuf *msgbuf;
2583        char *line_prefix = "";
2584
2585        *must_show_header = 1;
2586        if (o->output_prefix) {
2587                msgbuf = o->output_prefix(o, o->output_prefix_data);
2588                line_prefix = msgbuf->buf;
2589        }
2590        strbuf_init(msg, PATH_MAX * 2 + 300);
2591        switch (p->status) {
2592        case DIFF_STATUS_COPIED:
2593                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2594                            line_prefix, set, similarity_index(p));
2595                strbuf_addf(msg, "%s\n%s%scopy from ",
2596                            reset,  line_prefix, set);
2597                quote_c_style(name, msg, NULL, 0);
2598                strbuf_addf(msg, "%s\n%s%scopy to ", reset, line_prefix, set);
2599                quote_c_style(other, msg, NULL, 0);
2600                strbuf_addf(msg, "%s\n", reset);
2601                break;
2602        case DIFF_STATUS_RENAMED:
2603                strbuf_addf(msg, "%s%ssimilarity index %d%%",
2604                            line_prefix, set, similarity_index(p));
2605                strbuf_addf(msg, "%s\n%s%srename from ",
2606                            reset, line_prefix, set);
2607                quote_c_style(name, msg, NULL, 0);
2608                strbuf_addf(msg, "%s\n%s%srename to ",
2609                            reset, line_prefix, set);
2610                quote_c_style(other, msg, NULL, 0);
2611                strbuf_addf(msg, "%s\n", reset);
2612                break;
2613        case DIFF_STATUS_MODIFIED:
2614                if (p->score) {
2615                        strbuf_addf(msg, "%s%sdissimilarity index %d%%%s\n",
2616                                    line_prefix,
2617                                    set, similarity_index(p), reset);
2618                        break;
2619                }
2620                /* fallthru */
2621        default:
2622                *must_show_header = 0;
2623        }
2624        if (one && two && hashcmp(one->sha1, two->sha1)) {
2625                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2626
2627                if (DIFF_OPT_TST(o, BINARY)) {
2628                        mmfile_t mf;
2629                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2630                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2631                                abbrev = 40;
2632                }
2633                strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
2634                            find_unique_abbrev(one->sha1, abbrev));
2635                strbuf_addstr(msg, find_unique_abbrev(two->sha1, abbrev));
2636                if (one->mode == two->mode)
2637                        strbuf_addf(msg, " %06o", one->mode);
2638                strbuf_addf(msg, "%s\n", reset);
2639        }
2640}
2641
2642static void run_diff_cmd(const char *pgm,
2643                         const char *name,
2644                         const char *other,
2645                         const char *attr_path,
2646                         struct diff_filespec *one,
2647                         struct diff_filespec *two,
2648                         struct strbuf *msg,
2649                         struct diff_options *o,
2650                         struct diff_filepair *p)
2651{
2652        const char *xfrm_msg = NULL;
2653        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2654        int must_show_header = 0;
2655
2656        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2657                pgm = NULL;
2658        else {
2659                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2660                if (drv && drv->external)
2661                        pgm = drv->external;
2662        }
2663
2664        if (msg) {
2665                /*
2666                 * don't use colors when the header is intended for an
2667                 * external diff driver
2668                 */
2669                fill_metainfo(msg, name, other, one, two, o, p,
2670                              &must_show_header,
2671                              DIFF_OPT_TST(o, COLOR_DIFF) && !pgm);
2672                xfrm_msg = msg->len ? msg->buf : NULL;
2673        }
2674
2675        if (pgm) {
2676                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2677                                  complete_rewrite);
2678                return;
2679        }
2680        if (one && two)
2681                builtin_diff(name, other ? other : name,
2682                             one, two, xfrm_msg, must_show_header,
2683                             o, complete_rewrite);
2684        else
2685                fprintf(o->file, "* Unmerged path %s\n", name);
2686}
2687
2688static void diff_fill_sha1_info(struct diff_filespec *one)
2689{
2690        if (DIFF_FILE_VALID(one)) {
2691                if (!one->sha1_valid) {
2692                        struct stat st;
2693                        if (!strcmp(one->path, "-")) {
2694                                hashcpy(one->sha1, null_sha1);
2695                                return;
2696                        }
2697                        if (lstat(one->path, &st) < 0)
2698                                die_errno("stat '%s'", one->path);
2699                        if (index_path(one->sha1, one->path, &st, 0))
2700                                die("cannot hash %s", one->path);
2701                }
2702        }
2703        else
2704                hashclr(one->sha1);
2705}
2706
2707static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2708{
2709        /* Strip the prefix but do not molest /dev/null and absolute paths */
2710        if (*namep && **namep != '/') {
2711                *namep += prefix_length;
2712                if (**namep == '/')
2713                        ++*namep;
2714        }
2715        if (*otherp && **otherp != '/') {
2716                *otherp += prefix_length;
2717                if (**otherp == '/')
2718                        ++*otherp;
2719        }
2720}
2721
2722static void run_diff(struct diff_filepair *p, struct diff_options *o)
2723{
2724        const char *pgm = external_diff();
2725        struct strbuf msg;
2726        struct diff_filespec *one = p->one;
2727        struct diff_filespec *two = p->two;
2728        const char *name;
2729        const char *other;
2730        const char *attr_path;
2731
2732        name  = p->one->path;
2733        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2734        attr_path = name;
2735        if (o->prefix_length)
2736                strip_prefix(o->prefix_length, &name, &other);
2737
2738        if (DIFF_PAIR_UNMERGED(p)) {
2739                run_diff_cmd(pgm, name, NULL, attr_path,
2740                             NULL, NULL, NULL, o, p);
2741                return;
2742        }
2743
2744        diff_fill_sha1_info(one);
2745        diff_fill_sha1_info(two);
2746
2747        if (!pgm &&
2748            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2749            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2750                /*
2751                 * a filepair that changes between file and symlink
2752                 * needs to be split into deletion and creation.
2753                 */
2754                struct diff_filespec *null = alloc_filespec(two->path);
2755                run_diff_cmd(NULL, name, other, attr_path,
2756                             one, null, &msg, o, p);
2757                free(null);
2758                strbuf_release(&msg);
2759
2760                null = alloc_filespec(one->path);
2761                run_diff_cmd(NULL, name, other, attr_path,
2762                             null, two, &msg, o, p);
2763                free(null);
2764        }
2765        else
2766                run_diff_cmd(pgm, name, other, attr_path,
2767                             one, two, &msg, o, p);
2768
2769        strbuf_release(&msg);
2770}
2771
2772static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2773                         struct diffstat_t *diffstat)
2774{
2775        const char *name;
2776        const char *other;
2777        int complete_rewrite = 0;
2778
2779        if (DIFF_PAIR_UNMERGED(p)) {
2780                /* unmerged */
2781                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2782                return;
2783        }
2784
2785        name = p->one->path;
2786        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2787
2788        if (o->prefix_length)
2789                strip_prefix(o->prefix_length, &name, &other);
2790
2791        diff_fill_sha1_info(p->one);
2792        diff_fill_sha1_info(p->two);
2793
2794        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2795                complete_rewrite = 1;
2796        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2797}
2798
2799static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2800{
2801        const char *name;
2802        const char *other;
2803        const char *attr_path;
2804
2805        if (DIFF_PAIR_UNMERGED(p)) {
2806                /* unmerged */
2807                return;
2808        }
2809
2810        name = p->one->path;
2811        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2812        attr_path = other ? other : name;
2813
2814        if (o->prefix_length)
2815                strip_prefix(o->prefix_length, &name, &other);
2816
2817        diff_fill_sha1_info(p->one);
2818        diff_fill_sha1_info(p->two);
2819
2820        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2821}
2822
2823void diff_setup(struct diff_options *options)
2824{
2825        memset(options, 0, sizeof(*options));
2826
2827        options->file = stdout;
2828
2829        options->line_termination = '\n';
2830        options->break_opt = -1;
2831        options->rename_limit = -1;
2832        options->dirstat_percent = 3;
2833        options->context = 3;
2834
2835        options->change = diff_change;
2836        options->add_remove = diff_addremove;
2837        if (diff_use_color_default > 0)
2838                DIFF_OPT_SET(options, COLOR_DIFF);
2839        options->detect_rename = diff_detect_rename_default;
2840
2841        if (diff_no_prefix) {
2842                options->a_prefix = options->b_prefix = "";
2843        } else if (!diff_mnemonic_prefix) {
2844                options->a_prefix = "a/";
2845                options->b_prefix = "b/";
2846        }
2847}
2848
2849int diff_setup_done(struct diff_options *options)
2850{
2851        int count = 0;
2852
2853        if (options->output_format & DIFF_FORMAT_NAME)
2854                count++;
2855        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2856                count++;
2857        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2858                count++;
2859        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2860                count++;
2861        if (count > 1)
2862                die("--name-only, --name-status, --check and -s are mutually exclusive");
2863
2864        /*
2865         * Most of the time we can say "there are changes"
2866         * only by checking if there are changed paths, but
2867         * --ignore-whitespace* options force us to look
2868         * inside contents.
2869         */
2870
2871        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2872            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2873            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2874                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2875        else
2876                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2877
2878        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2879                options->detect_rename = DIFF_DETECT_COPY;
2880
2881        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2882                options->prefix = NULL;
2883        if (options->prefix)
2884                options->prefix_length = strlen(options->prefix);
2885        else
2886                options->prefix_length = 0;
2887
2888        if (options->output_format & (DIFF_FORMAT_NAME |
2889                                      DIFF_FORMAT_NAME_STATUS |
2890                                      DIFF_FORMAT_CHECKDIFF |
2891                                      DIFF_FORMAT_NO_OUTPUT))
2892                options->output_format &= ~(DIFF_FORMAT_RAW |
2893                                            DIFF_FORMAT_NUMSTAT |
2894                                            DIFF_FORMAT_DIFFSTAT |
2895                                            DIFF_FORMAT_SHORTSTAT |
2896                                            DIFF_FORMAT_DIRSTAT |
2897                                            DIFF_FORMAT_SUMMARY |
2898                                            DIFF_FORMAT_PATCH);
2899
2900        /*
2901         * These cases always need recursive; we do not drop caller-supplied
2902         * recursive bits for other formats here.
2903         */
2904        if (options->output_format & (DIFF_FORMAT_PATCH |
2905                                      DIFF_FORMAT_NUMSTAT |
2906                                      DIFF_FORMAT_DIFFSTAT |
2907                                      DIFF_FORMAT_SHORTSTAT |
2908                                      DIFF_FORMAT_DIRSTAT |
2909                                      DIFF_FORMAT_SUMMARY |
2910                                      DIFF_FORMAT_CHECKDIFF))
2911                DIFF_OPT_SET(options, RECURSIVE);
2912        /*
2913         * Also pickaxe would not work very well if you do not say recursive
2914         */
2915        if (options->pickaxe)
2916                DIFF_OPT_SET(options, RECURSIVE);
2917        /*
2918         * When patches are generated, submodules diffed against the work tree
2919         * must be checked for dirtiness too so it can be shown in the output
2920         */
2921        if (options->output_format & DIFF_FORMAT_PATCH)
2922                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2923
2924        if (options->detect_rename && options->rename_limit < 0)
2925                options->rename_limit = diff_rename_limit_default;
2926        if (options->setup & DIFF_SETUP_USE_CACHE) {
2927                if (!active_cache)
2928                        /* read-cache does not die even when it fails
2929                         * so it is safe for us to do this here.  Also
2930                         * it does not smudge active_cache or active_nr
2931                         * when it fails, so we do not have to worry about
2932                         * cleaning it up ourselves either.
2933                         */
2934                        read_cache();
2935        }
2936        if (options->abbrev <= 0 || 40 < options->abbrev)
2937                options->abbrev = 40; /* full */
2938
2939        /*
2940         * It does not make sense to show the first hit we happened
2941         * to have found.  It does not make sense not to return with
2942         * exit code in such a case either.
2943         */
2944        if (DIFF_OPT_TST(options, QUICK)) {
2945                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2946                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2947        }
2948
2949        return 0;
2950}
2951
2952static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2953{
2954        char c, *eq;
2955        int len;
2956
2957        if (*arg != '-')
2958                return 0;
2959        c = *++arg;
2960        if (!c)
2961                return 0;
2962        if (c == arg_short) {
2963                c = *++arg;
2964                if (!c)
2965                        return 1;
2966                if (val && isdigit(c)) {
2967                        char *end;
2968                        int n = strtoul(arg, &end, 10);
2969                        if (*end)
2970                                return 0;
2971                        *val = n;
2972                        return 1;
2973                }
2974                return 0;
2975        }
2976        if (c != '-')
2977                return 0;
2978        arg++;
2979        eq = strchr(arg, '=');
2980        if (eq)
2981                len = eq - arg;
2982        else
2983                len = strlen(arg);
2984        if (!len || strncmp(arg, arg_long, len))
2985                return 0;
2986        if (eq) {
2987                int n;
2988                char *end;
2989                if (!isdigit(*++eq))
2990                        return 0;
2991                n = strtoul(eq, &end, 10);
2992                if (*end)
2993                        return 0;
2994                *val = n;
2995        }
2996        return 1;
2997}
2998
2999static int diff_scoreopt_parse(const char *opt);
3000
3001int diff_opt_parse(struct diff_options *options, const char **av, int ac)
3002{
3003        const char *arg = av[0];
3004
3005        /* Output format options */
3006        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
3007                options->output_format |= DIFF_FORMAT_PATCH;
3008        else if (opt_arg(arg, 'U', "unified", &options->context))
3009                options->output_format |= DIFF_FORMAT_PATCH;
3010        else if (!strcmp(arg, "--raw"))
3011                options->output_format |= DIFF_FORMAT_RAW;
3012        else if (!strcmp(arg, "--patch-with-raw"))
3013                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
3014        else if (!strcmp(arg, "--numstat"))
3015                options->output_format |= DIFF_FORMAT_NUMSTAT;
3016        else if (!strcmp(arg, "--shortstat"))
3017                options->output_format |= DIFF_FORMAT_SHORTSTAT;
3018        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
3019                options->output_format |= DIFF_FORMAT_DIRSTAT;
3020        else if (!strcmp(arg, "--cumulative")) {
3021                options->output_format |= DIFF_FORMAT_DIRSTAT;
3022                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
3023        } else if (opt_arg(arg, 0, "dirstat-by-file",
3024                           &options->dirstat_percent)) {
3025                options->output_format |= DIFF_FORMAT_DIRSTAT;
3026                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
3027        }
3028        else if (!strcmp(arg, "--check"))
3029                options->output_format |= DIFF_FORMAT_CHECKDIFF;
3030        else if (!strcmp(arg, "--summary"))
3031                options->output_format |= DIFF_FORMAT_SUMMARY;
3032        else if (!strcmp(arg, "--patch-with-stat"))
3033                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
3034        else if (!strcmp(arg, "--name-only"))
3035                options->output_format |= DIFF_FORMAT_NAME;
3036        else if (!strcmp(arg, "--name-status"))
3037                options->output_format |= DIFF_FORMAT_NAME_STATUS;
3038        else if (!strcmp(arg, "-s"))
3039                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
3040        else if (!prefixcmp(arg, "--stat")) {
3041                char *end;
3042                int width = options->stat_width;
3043                int name_width = options->stat_name_width;
3044                arg += 6;
3045                end = (char *)arg;
3046
3047                switch (*arg) {
3048                case '-':
3049                        if (!prefixcmp(arg, "-width="))
3050                                width = strtoul(arg + 7, &end, 10);
3051                        else if (!prefixcmp(arg, "-name-width="))
3052                                name_width = strtoul(arg + 12, &end, 10);
3053                        break;
3054                case '=':
3055                        width = strtoul(arg+1, &end, 10);
3056                        if (*end == ',')
3057                                name_width = strtoul(end+1, &end, 10);
3058                }
3059
3060                /* Important! This checks all the error cases! */
3061                if (*end)
3062                        return 0;
3063                options->output_format |= DIFF_FORMAT_DIFFSTAT;
3064                options->stat_name_width = name_width;
3065                options->stat_width = width;
3066        }
3067
3068        /* renames options */
3069        else if (!prefixcmp(arg, "-B")) {
3070                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
3071                        return -1;
3072        }
3073        else if (!prefixcmp(arg, "-M")) {
3074                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3075                        return -1;
3076                options->detect_rename = DIFF_DETECT_RENAME;
3077        }
3078        else if (!prefixcmp(arg, "-C")) {
3079                if (options->detect_rename == DIFF_DETECT_COPY)
3080                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3081                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
3082                        return -1;
3083                options->detect_rename = DIFF_DETECT_COPY;
3084        }
3085        else if (!strcmp(arg, "--no-renames"))
3086                options->detect_rename = 0;
3087        else if (!strcmp(arg, "--relative"))
3088                DIFF_OPT_SET(options, RELATIVE_NAME);
3089        else if (!prefixcmp(arg, "--relative=")) {
3090                DIFF_OPT_SET(options, RELATIVE_NAME);
3091                options->prefix = arg + 11;
3092        }
3093
3094        /* xdiff options */
3095        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
3096                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
3097        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
3098                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
3099        else if (!strcmp(arg, "--ignore-space-at-eol"))
3100                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
3101        else if (!strcmp(arg, "--patience"))
3102                DIFF_XDL_SET(options, PATIENCE_DIFF);
3103
3104        /* flags options */
3105        else if (!strcmp(arg, "--binary")) {
3106                options->output_format |= DIFF_FORMAT_PATCH;
3107                DIFF_OPT_SET(options, BINARY);
3108        }
3109        else if (!strcmp(arg, "--full-index"))
3110                DIFF_OPT_SET(options, FULL_INDEX);
3111        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
3112                DIFF_OPT_SET(options, TEXT);
3113        else if (!strcmp(arg, "-R"))
3114                DIFF_OPT_SET(options, REVERSE_DIFF);
3115        else if (!strcmp(arg, "--find-copies-harder"))
3116                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
3117        else if (!strcmp(arg, "--follow"))
3118                DIFF_OPT_SET(options, FOLLOW_RENAMES);
3119        else if (!strcmp(arg, "--color"))
3120                DIFF_OPT_SET(options, COLOR_DIFF);
3121        else if (!prefixcmp(arg, "--color=")) {
3122                int value = git_config_colorbool(NULL, arg+8, -1);
3123                if (value == 0)
3124                        DIFF_OPT_CLR(options, COLOR_DIFF);
3125                else if (value > 0)
3126                        DIFF_OPT_SET(options, COLOR_DIFF);
3127                else
3128                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3129        }
3130        else if (!strcmp(arg, "--no-color"))
3131                DIFF_OPT_CLR(options, COLOR_DIFF);
3132        else if (!strcmp(arg, "--color-words")) {
3133                DIFF_OPT_SET(options, COLOR_DIFF);
3134                options->word_diff = DIFF_WORDS_COLOR;
3135        }
3136        else if (!prefixcmp(arg, "--color-words=")) {
3137                DIFF_OPT_SET(options, COLOR_DIFF);
3138                options->word_diff = DIFF_WORDS_COLOR;
3139                options->word_regex = arg + 14;
3140        }
3141        else if (!strcmp(arg, "--word-diff")) {
3142                if (options->word_diff == DIFF_WORDS_NONE)
3143                        options->word_diff = DIFF_WORDS_PLAIN;
3144        }
3145        else if (!prefixcmp(arg, "--word-diff=")) {
3146                const char *type = arg + 12;
3147                if (!strcmp(type, "plain"))
3148                        options->word_diff = DIFF_WORDS_PLAIN;
3149                else if (!strcmp(type, "color")) {
3150                        DIFF_OPT_SET(options, COLOR_DIFF);
3151                        options->word_diff = DIFF_WORDS_COLOR;
3152                }
3153                else if (!strcmp(type, "porcelain"))
3154                        options->word_diff = DIFF_WORDS_PORCELAIN;
3155                else if (!strcmp(type, "none"))
3156                        options->word_diff = DIFF_WORDS_NONE;
3157                else
3158                        die("bad --word-diff argument: %s", type);
3159        }
3160        else if (!prefixcmp(arg, "--word-diff-regex=")) {
3161                if (options->word_diff == DIFF_WORDS_NONE)
3162                        options->word_diff = DIFF_WORDS_PLAIN;
3163                options->word_regex = arg + 18;
3164        }
3165        else if (!strcmp(arg, "--exit-code"))
3166                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3167        else if (!strcmp(arg, "--quiet"))
3168                DIFF_OPT_SET(options, QUICK);
3169        else if (!strcmp(arg, "--ext-diff"))
3170                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3171        else if (!strcmp(arg, "--no-ext-diff"))
3172                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3173        else if (!strcmp(arg, "--textconv"))
3174                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3175        else if (!strcmp(arg, "--no-textconv"))
3176                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3177        else if (!strcmp(arg, "--ignore-submodules"))
3178                handle_ignore_submodules_arg(options, "all");
3179        else if (!prefixcmp(arg, "--ignore-submodules="))
3180                handle_ignore_submodules_arg(options, arg + 20);
3181        else if (!strcmp(arg, "--submodule"))
3182                DIFF_OPT_SET(options, SUBMODULE_LOG);
3183        else if (!prefixcmp(arg, "--submodule=")) {
3184                if (!strcmp(arg + 12, "log"))
3185                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3186        }
3187
3188        /* misc options */
3189        else if (!strcmp(arg, "-z"))
3190                options->line_termination = 0;
3191        else if (!prefixcmp(arg, "-l"))
3192                options->rename_limit = strtoul(arg+2, NULL, 10);
3193        else if (!prefixcmp(arg, "-S"))
3194                options->pickaxe = arg + 2;
3195        else if (!strcmp(arg, "--pickaxe-all"))
3196                options->pickaxe_opts = DIFF_PICKAXE_ALL;
3197        else if (!strcmp(arg, "--pickaxe-regex"))
3198                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
3199        else if (!prefixcmp(arg, "-O"))
3200                options->orderfile = arg + 2;
3201        else if (!prefixcmp(arg, "--diff-filter="))
3202                options->filter = arg + 14;
3203        else if (!strcmp(arg, "--abbrev"))
3204                options->abbrev = DEFAULT_ABBREV;
3205        else if (!prefixcmp(arg, "--abbrev=")) {
3206                options->abbrev = strtoul(arg + 9, NULL, 10);
3207                if (options->abbrev < MINIMUM_ABBREV)
3208                        options->abbrev = MINIMUM_ABBREV;
3209                else if (40 < options->abbrev)
3210                        options->abbrev = 40;
3211        }
3212        else if (!prefixcmp(arg, "--src-prefix="))
3213                options->a_prefix = arg + 13;
3214        else if (!prefixcmp(arg, "--dst-prefix="))
3215                options->b_prefix = arg + 13;
3216        else if (!strcmp(arg, "--no-prefix"))
3217                options->a_prefix = options->b_prefix = "";
3218        else if (opt_arg(arg, '\0', "inter-hunk-context",
3219                         &options->interhunkcontext))
3220                ;
3221        else if (!prefixcmp(arg, "--output=")) {
3222                options->file = fopen(arg + strlen("--output="), "w");
3223                if (!options->file)
3224                        die_errno("Could not open '%s'", arg + strlen("--output="));
3225                options->close_file = 1;
3226        } else
3227                return 0;
3228        return 1;
3229}
3230
3231static int parse_num(const char **cp_p)
3232{
3233        unsigned long num, scale;
3234        int ch, dot;
3235        const char *cp = *cp_p;
3236
3237        num = 0;
3238        scale = 1;
3239        dot = 0;
3240        for (;;) {
3241                ch = *cp;
3242                if ( !dot && ch == '.' ) {
3243                        scale = 1;
3244                        dot = 1;
3245                } else if ( ch == '%' ) {
3246                        scale = dot ? scale*100 : 100;
3247                        cp++;   /* % is always at the end */
3248                        break;
3249                } else if ( ch >= '0' && ch <= '9' ) {
3250                        if ( scale < 100000 ) {
3251                                scale *= 10;
3252                                num = (num*10) + (ch-'0');
3253                        }
3254                } else {
3255                        break;
3256                }
3257                cp++;
3258        }
3259        *cp_p = cp;
3260
3261        /* user says num divided by scale and we say internally that
3262         * is MAX_SCORE * num / scale.
3263         */
3264        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3265}
3266
3267static int diff_scoreopt_parse(const char *opt)
3268{
3269        int opt1, opt2, cmd;
3270
3271        if (*opt++ != '-')
3272                return -1;
3273        cmd = *opt++;
3274        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3275                return -1; /* that is not a -M, -C nor -B option */
3276
3277        opt1 = parse_num(&opt);
3278        if (cmd != 'B')
3279                opt2 = 0;
3280        else {
3281                if (*opt == 0)
3282                        opt2 = 0;
3283                else if (*opt != '/')
3284                        return -1; /* we expect -B80/99 or -B80 */
3285                else {
3286                        opt++;
3287                        opt2 = parse_num(&opt);
3288                }
3289        }
3290        if (*opt != 0)
3291                return -1;
3292        return opt1 | (opt2 << 16);
3293}
3294
3295struct diff_queue_struct diff_queued_diff;
3296
3297void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3298{
3299        if (queue->alloc <= queue->nr) {
3300                queue->alloc = alloc_nr(queue->alloc);
3301                queue->queue = xrealloc(queue->queue,
3302                                        sizeof(dp) * queue->alloc);
3303        }
3304        queue->queue[queue->nr++] = dp;
3305}
3306
3307struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3308                                 struct diff_filespec *one,
3309                                 struct diff_filespec *two)
3310{
3311        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3312        dp->one = one;
3313        dp->two = two;
3314        if (queue)
3315                diff_q(queue, dp);
3316        return dp;
3317}
3318
3319void diff_free_filepair(struct diff_filepair *p)
3320{
3321        free_filespec(p->one);
3322        free_filespec(p->two);
3323        free(p);
3324}
3325
3326/* This is different from find_unique_abbrev() in that
3327 * it stuffs the result with dots for alignment.
3328 */
3329const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3330{
3331        int abblen;
3332        const char *abbrev;
3333        if (len == 40)
3334                return sha1_to_hex(sha1);
3335
3336        abbrev = find_unique_abbrev(sha1, len);
3337        abblen = strlen(abbrev);
3338        if (abblen < 37) {
3339                static char hex[41];
3340                if (len < abblen && abblen <= len + 2)
3341                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3342                else
3343                        sprintf(hex, "%s...", abbrev);
3344                return hex;
3345        }
3346        return sha1_to_hex(sha1);
3347}
3348
3349static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3350{
3351        int line_termination = opt->line_termination;
3352        int inter_name_termination = line_termination ? '\t' : '\0';
3353        if (opt->output_prefix) {
3354                struct strbuf *msg = NULL;
3355                msg = opt->output_prefix(opt, opt->output_prefix_data);
3356                fprintf(opt->file, "%s", msg->buf);
3357        }
3358
3359        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3360                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3361                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3362                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3363        }
3364        if (p->score) {
3365                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3366                        inter_name_termination);
3367        } else {
3368                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3369        }
3370
3371        if (p->status == DIFF_STATUS_COPIED ||
3372            p->status == DIFF_STATUS_RENAMED) {
3373                const char *name_a, *name_b;
3374                name_a = p->one->path;
3375                name_b = p->two->path;
3376                strip_prefix(opt->prefix_length, &name_a, &name_b);
3377                write_name_quoted(name_a, opt->file, inter_name_termination);
3378                write_name_quoted(name_b, opt->file, line_termination);
3379        } else {
3380                const char *name_a, *name_b;
3381                name_a = p->one->mode ? p->one->path : p->two->path;
3382                name_b = NULL;
3383                strip_prefix(opt->prefix_length, &name_a, &name_b);
3384                write_name_quoted(name_a, opt->file, line_termination);
3385        }
3386}
3387
3388int diff_unmodified_pair(struct diff_filepair *p)
3389{
3390        /* This function is written stricter than necessary to support
3391         * the currently implemented transformers, but the idea is to
3392         * let transformers to produce diff_filepairs any way they want,
3393         * and filter and clean them up here before producing the output.
3394         */
3395        struct diff_filespec *one = p->one, *two = p->two;
3396
3397        if (DIFF_PAIR_UNMERGED(p))
3398                return 0; /* unmerged is interesting */
3399
3400        /* deletion, addition, mode or type change
3401         * and rename are all interesting.
3402         */
3403        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3404            DIFF_PAIR_MODE_CHANGED(p) ||
3405            strcmp(one->path, two->path))
3406                return 0;
3407
3408        /* both are valid and point at the same path.  that is, we are
3409         * dealing with a change.
3410         */
3411        if (one->sha1_valid && two->sha1_valid &&
3412            !hashcmp(one->sha1, two->sha1) &&
3413            !one->dirty_submodule && !two->dirty_submodule)
3414                return 1; /* no change */
3415        if (!one->sha1_valid && !two->sha1_valid)
3416                return 1; /* both look at the same file on the filesystem. */
3417        return 0;
3418}
3419
3420static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3421{
3422        if (diff_unmodified_pair(p))
3423                return;
3424
3425        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3426            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3427                return; /* no tree diffs in patch format */
3428
3429        run_diff(p, o);
3430}
3431
3432static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3433                            struct diffstat_t *diffstat)
3434{
3435        if (diff_unmodified_pair(p))
3436                return;
3437
3438        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3439            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3440                return; /* no tree diffs in patch format */
3441
3442        run_diffstat(p, o, diffstat);
3443}
3444
3445static void diff_flush_checkdiff(struct diff_filepair *p,
3446                struct diff_options *o)
3447{
3448        if (diff_unmodified_pair(p))
3449                return;
3450
3451        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3452            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3453                return; /* no tree diffs in patch format */
3454
3455        run_checkdiff(p, o);
3456}
3457
3458int diff_queue_is_empty(void)
3459{
3460        struct diff_queue_struct *q = &diff_queued_diff;
3461        int i;
3462        for (i = 0; i < q->nr; i++)
3463                if (!diff_unmodified_pair(q->queue[i]))
3464                        return 0;
3465        return 1;
3466}
3467
3468#if DIFF_DEBUG
3469void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3470{
3471        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3472                x, one ? one : "",
3473                s->path,
3474                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3475                s->mode,
3476                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3477        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3478                x, one ? one : "",
3479                s->size, s->xfrm_flags);
3480}
3481
3482void diff_debug_filepair(const struct diff_filepair *p, int i)
3483{
3484        diff_debug_filespec(p->one, i, "one");
3485        diff_debug_filespec(p->two, i, "two");
3486        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3487                p->score, p->status ? p->status : '?',
3488                p->one->rename_used, p->broken_pair);
3489}
3490
3491void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3492{
3493        int i;
3494        if (msg)
3495                fprintf(stderr, "%s\n", msg);
3496        fprintf(stderr, "q->nr = %d\n", q->nr);
3497        for (i = 0; i < q->nr; i++) {
3498                struct diff_filepair *p = q->queue[i];
3499                diff_debug_filepair(p, i);
3500        }
3501}
3502#endif
3503
3504static void diff_resolve_rename_copy(void)
3505{
3506        int i;
3507        struct diff_filepair *p;
3508        struct diff_queue_struct *q = &diff_queued_diff;
3509
3510        diff_debug_queue("resolve-rename-copy", q);
3511
3512        for (i = 0; i < q->nr; i++) {
3513                p = q->queue[i];
3514                p->status = 0; /* undecided */
3515                if (DIFF_PAIR_UNMERGED(p))
3516                        p->status = DIFF_STATUS_UNMERGED;
3517                else if (!DIFF_FILE_VALID(p->one))
3518                        p->status = DIFF_STATUS_ADDED;
3519                else if (!DIFF_FILE_VALID(p->two))
3520                        p->status = DIFF_STATUS_DELETED;
3521                else if (DIFF_PAIR_TYPE_CHANGED(p))
3522                        p->status = DIFF_STATUS_TYPE_CHANGED;
3523
3524                /* from this point on, we are dealing with a pair
3525                 * whose both sides are valid and of the same type, i.e.
3526                 * either in-place edit or rename/copy edit.
3527                 */
3528                else if (DIFF_PAIR_RENAME(p)) {
3529                        /*
3530                         * A rename might have re-connected a broken
3531                         * pair up, causing the pathnames to be the
3532                         * same again. If so, that's not a rename at
3533                         * all, just a modification..
3534                         *
3535                         * Otherwise, see if this source was used for
3536                         * multiple renames, in which case we decrement
3537                         * the count, and call it a copy.
3538                         */
3539                        if (!strcmp(p->one->path, p->two->path))
3540                                p->status = DIFF_STATUS_MODIFIED;
3541                        else if (--p->one->rename_used > 0)
3542                                p->status = DIFF_STATUS_COPIED;
3543                        else
3544                                p->status = DIFF_STATUS_RENAMED;
3545                }
3546                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3547                         p->one->mode != p->two->mode ||
3548                         p->one->dirty_submodule ||
3549                         p->two->dirty_submodule ||
3550                         is_null_sha1(p->one->sha1))
3551                        p->status = DIFF_STATUS_MODIFIED;
3552                else {
3553                        /* This is a "no-change" entry and should not
3554                         * happen anymore, but prepare for broken callers.
3555                         */
3556                        error("feeding unmodified %s to diffcore",
3557                              p->one->path);
3558                        p->status = DIFF_STATUS_UNKNOWN;
3559                }
3560        }
3561        diff_debug_queue("resolve-rename-copy done", q);
3562}
3563
3564static int check_pair_status(struct diff_filepair *p)
3565{
3566        switch (p->status) {
3567        case DIFF_STATUS_UNKNOWN:
3568                return 0;
3569        case 0:
3570                die("internal error in diff-resolve-rename-copy");
3571        default:
3572                return 1;
3573        }
3574}
3575
3576static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3577{
3578        int fmt = opt->output_format;
3579
3580        if (fmt & DIFF_FORMAT_CHECKDIFF)
3581                diff_flush_checkdiff(p, opt);
3582        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3583                diff_flush_raw(p, opt);
3584        else if (fmt & DIFF_FORMAT_NAME) {
3585                const char *name_a, *name_b;
3586                name_a = p->two->path;
3587                name_b = NULL;
3588                strip_prefix(opt->prefix_length, &name_a, &name_b);
3589                write_name_quoted(name_a, opt->file, opt->line_termination);
3590        }
3591}
3592
3593static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3594{
3595        if (fs->mode)
3596                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3597        else
3598                fprintf(file, " %s ", newdelete);
3599        write_name_quoted(fs->path, file, '\n');
3600}
3601
3602
3603static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3604                const char *line_prefix)
3605{
3606        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3607                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3608                        p->two->mode, show_name ? ' ' : '\n');
3609                if (show_name) {
3610                        write_name_quoted(p->two->path, file, '\n');
3611                }
3612        }
3613}
3614
3615static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3616                        const char *line_prefix)
3617{
3618        char *names = pprint_rename(p->one->path, p->two->path);
3619
3620        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3621        free(names);
3622        show_mode_change(file, p, 0, line_prefix);
3623}
3624
3625static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3626{
3627        FILE *file = opt->file;
3628        char *line_prefix = "";
3629
3630        if (opt->output_prefix) {
3631                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3632                line_prefix = buf->buf;
3633        }
3634
3635        switch(p->status) {
3636        case DIFF_STATUS_DELETED:
3637                fputs(line_prefix, file);
3638                show_file_mode_name(file, "delete", p->one);
3639                break;
3640        case DIFF_STATUS_ADDED:
3641                fputs(line_prefix, file);
3642                show_file_mode_name(file, "create", p->two);
3643                break;
3644        case DIFF_STATUS_COPIED:
3645                fputs(line_prefix, file);
3646                show_rename_copy(file, "copy", p, line_prefix);
3647                break;
3648        case DIFF_STATUS_RENAMED:
3649                fputs(line_prefix, file);
3650                show_rename_copy(file, "rename", p, line_prefix);
3651                break;
3652        default:
3653                if (p->score) {
3654                        fprintf(file, "%s rewrite ", line_prefix);
3655                        write_name_quoted(p->two->path, file, ' ');
3656                        fprintf(file, "(%d%%)\n", similarity_index(p));
3657                }
3658                show_mode_change(file, p, !p->score, line_prefix);
3659                break;
3660        }
3661}
3662
3663struct patch_id_t {
3664        git_SHA_CTX *ctx;
3665        int patchlen;
3666};
3667
3668static int remove_space(char *line, int len)
3669{
3670        int i;
3671        char *dst = line;
3672        unsigned char c;
3673
3674        for (i = 0; i < len; i++)
3675                if (!isspace((c = line[i])))
3676                        *dst++ = c;
3677
3678        return dst - line;
3679}
3680
3681static void patch_id_consume(void *priv, char *line, unsigned long len)
3682{
3683        struct patch_id_t *data = priv;
3684        int new_len;
3685
3686        /* Ignore line numbers when computing the SHA1 of the patch */
3687        if (!prefixcmp(line, "@@ -"))
3688                return;
3689
3690        new_len = remove_space(line, len);
3691
3692        git_SHA1_Update(data->ctx, line, new_len);
3693        data->patchlen += new_len;
3694}
3695
3696/* returns 0 upon success, and writes result into sha1 */
3697static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3698{
3699        struct diff_queue_struct *q = &diff_queued_diff;
3700        int i;
3701        git_SHA_CTX ctx;
3702        struct patch_id_t data;
3703        char buffer[PATH_MAX * 4 + 20];
3704
3705        git_SHA1_Init(&ctx);
3706        memset(&data, 0, sizeof(struct patch_id_t));
3707        data.ctx = &ctx;
3708
3709        for (i = 0; i < q->nr; i++) {
3710                xpparam_t xpp;
3711                xdemitconf_t xecfg;
3712                mmfile_t mf1, mf2;
3713                struct diff_filepair *p = q->queue[i];
3714                int len1, len2;
3715
3716                memset(&xpp, 0, sizeof(xpp));
3717                memset(&xecfg, 0, sizeof(xecfg));
3718                if (p->status == 0)
3719                        return error("internal diff status error");
3720                if (p->status == DIFF_STATUS_UNKNOWN)
3721                        continue;
3722                if (diff_unmodified_pair(p))
3723                        continue;
3724                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3725                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3726                        continue;
3727                if (DIFF_PAIR_UNMERGED(p))
3728                        continue;
3729
3730                diff_fill_sha1_info(p->one);
3731                diff_fill_sha1_info(p->two);
3732                if (fill_mmfile(&mf1, p->one) < 0 ||
3733                                fill_mmfile(&mf2, p->two) < 0)
3734                        return error("unable to read files to diff");
3735
3736                len1 = remove_space(p->one->path, strlen(p->one->path));
3737                len2 = remove_space(p->two->path, strlen(p->two->path));
3738                if (p->one->mode == 0)
3739                        len1 = snprintf(buffer, sizeof(buffer),
3740                                        "diff--gita/%.*sb/%.*s"
3741                                        "newfilemode%06o"
3742                                        "---/dev/null"
3743                                        "+++b/%.*s",
3744                                        len1, p->one->path,
3745                                        len2, p->two->path,
3746                                        p->two->mode,
3747                                        len2, p->two->path);
3748                else if (p->two->mode == 0)
3749                        len1 = snprintf(buffer, sizeof(buffer),
3750                                        "diff--gita/%.*sb/%.*s"
3751                                        "deletedfilemode%06o"
3752                                        "---a/%.*s"
3753                                        "+++/dev/null",
3754                                        len1, p->one->path,
3755                                        len2, p->two->path,
3756                                        p->one->mode,
3757                                        len1, p->one->path);
3758                else
3759                        len1 = snprintf(buffer, sizeof(buffer),
3760                                        "diff--gita/%.*sb/%.*s"
3761                                        "---a/%.*s"
3762                                        "+++b/%.*s",
3763                                        len1, p->one->path,
3764                                        len2, p->two->path,
3765                                        len1, p->one->path,
3766                                        len2, p->two->path);
3767                git_SHA1_Update(&ctx, buffer, len1);
3768
3769                xpp.flags = 0;
3770                xecfg.ctxlen = 3;
3771                xecfg.flags = 0;
3772                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3773                              &xpp, &xecfg);
3774        }
3775
3776        git_SHA1_Final(sha1, &ctx);
3777        return 0;
3778}
3779
3780int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3781{
3782        struct diff_queue_struct *q = &diff_queued_diff;
3783        int i;
3784        int result = diff_get_patch_id(options, sha1);
3785
3786        for (i = 0; i < q->nr; i++)
3787                diff_free_filepair(q->queue[i]);
3788
3789        free(q->queue);
3790        DIFF_QUEUE_CLEAR(q);
3791
3792        return result;
3793}
3794
3795static int is_summary_empty(const struct diff_queue_struct *q)
3796{
3797        int i;
3798
3799        for (i = 0; i < q->nr; i++) {
3800                const struct diff_filepair *p = q->queue[i];
3801
3802                switch (p->status) {
3803                case DIFF_STATUS_DELETED:
3804                case DIFF_STATUS_ADDED:
3805                case DIFF_STATUS_COPIED:
3806                case DIFF_STATUS_RENAMED:
3807                        return 0;
3808                default:
3809                        if (p->score)
3810                                return 0;
3811                        if (p->one->mode && p->two->mode &&
3812                            p->one->mode != p->two->mode)
3813                                return 0;
3814                        break;
3815                }
3816        }
3817        return 1;
3818}
3819
3820void diff_flush(struct diff_options *options)
3821{
3822        struct diff_queue_struct *q = &diff_queued_diff;
3823        int i, output_format = options->output_format;
3824        int separator = 0;
3825
3826        /*
3827         * Order: raw, stat, summary, patch
3828         * or:    name/name-status/checkdiff (other bits clear)
3829         */
3830        if (!q->nr)
3831                goto free_queue;
3832
3833        if (output_format & (DIFF_FORMAT_RAW |
3834                             DIFF_FORMAT_NAME |
3835                             DIFF_FORMAT_NAME_STATUS |
3836                             DIFF_FORMAT_CHECKDIFF)) {
3837                for (i = 0; i < q->nr; i++) {
3838                        struct diff_filepair *p = q->queue[i];
3839                        if (check_pair_status(p))
3840                                flush_one_pair(p, options);
3841                }
3842                separator++;
3843        }
3844
3845        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3846                struct diffstat_t diffstat;
3847
3848                memset(&diffstat, 0, sizeof(struct diffstat_t));
3849                for (i = 0; i < q->nr; i++) {
3850                        struct diff_filepair *p = q->queue[i];
3851                        if (check_pair_status(p))
3852                                diff_flush_stat(p, options, &diffstat);
3853                }
3854                if (output_format & DIFF_FORMAT_NUMSTAT)
3855                        show_numstat(&diffstat, options);
3856                if (output_format & DIFF_FORMAT_DIFFSTAT)
3857                        show_stats(&diffstat, options);
3858                if (output_format & DIFF_FORMAT_SHORTSTAT)
3859                        show_shortstats(&diffstat, options);
3860                free_diffstat_info(&diffstat);
3861                separator++;
3862        }
3863        if (output_format & DIFF_FORMAT_DIRSTAT)
3864                show_dirstat(options);
3865
3866        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3867                for (i = 0; i < q->nr; i++) {
3868                        diff_summary(options, q->queue[i]);
3869                }
3870                separator++;
3871        }
3872
3873        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3874            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3875            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3876                /*
3877                 * run diff_flush_patch for the exit status. setting
3878                 * options->file to /dev/null should be safe, becaue we
3879                 * aren't supposed to produce any output anyway.
3880                 */
3881                if (options->close_file)
3882                        fclose(options->file);
3883                options->file = fopen("/dev/null", "w");
3884                if (!options->file)
3885                        die_errno("Could not open /dev/null");
3886                options->close_file = 1;
3887                for (i = 0; i < q->nr; i++) {
3888                        struct diff_filepair *p = q->queue[i];
3889                        if (check_pair_status(p))
3890                                diff_flush_patch(p, options);
3891                        if (options->found_changes)
3892                                break;
3893                }
3894        }
3895
3896        if (output_format & DIFF_FORMAT_PATCH) {
3897                if (separator) {
3898                        putc(options->line_termination, options->file);
3899                        if (options->stat_sep) {
3900                                /* attach patch instead of inline */
3901                                fputs(options->stat_sep, options->file);
3902                        }
3903                }
3904
3905                for (i = 0; i < q->nr; i++) {
3906                        struct diff_filepair *p = q->queue[i];
3907                        if (check_pair_status(p))
3908                                diff_flush_patch(p, options);
3909                }
3910        }
3911
3912        if (output_format & DIFF_FORMAT_CALLBACK)
3913                options->format_callback(q, options, options->format_callback_data);
3914
3915        for (i = 0; i < q->nr; i++)
3916                diff_free_filepair(q->queue[i]);
3917free_queue:
3918        free(q->queue);
3919        DIFF_QUEUE_CLEAR(q);
3920        if (options->close_file)
3921                fclose(options->file);
3922
3923        /*
3924         * Report the content-level differences with HAS_CHANGES;
3925         * diff_addremove/diff_change does not set the bit when
3926         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3927         */
3928        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3929                if (options->found_changes)
3930                        DIFF_OPT_SET(options, HAS_CHANGES);
3931                else
3932                        DIFF_OPT_CLR(options, HAS_CHANGES);
3933        }
3934}
3935
3936static void diffcore_apply_filter(const char *filter)
3937{
3938        int i;
3939        struct diff_queue_struct *q = &diff_queued_diff;
3940        struct diff_queue_struct outq;
3941        DIFF_QUEUE_CLEAR(&outq);
3942
3943        if (!filter)
3944                return;
3945
3946        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3947                int found;
3948                for (i = found = 0; !found && i < q->nr; i++) {
3949                        struct diff_filepair *p = q->queue[i];
3950                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3951                             ((p->score &&
3952                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3953                              (!p->score &&
3954                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3955                            ((p->status != DIFF_STATUS_MODIFIED) &&
3956                             strchr(filter, p->status)))
3957                                found++;
3958                }
3959                if (found)
3960                        return;
3961
3962                /* otherwise we will clear the whole queue
3963                 * by copying the empty outq at the end of this
3964                 * function, but first clear the current entries
3965                 * in the queue.
3966                 */
3967                for (i = 0; i < q->nr; i++)
3968                        diff_free_filepair(q->queue[i]);
3969        }
3970        else {
3971                /* Only the matching ones */
3972                for (i = 0; i < q->nr; i++) {
3973                        struct diff_filepair *p = q->queue[i];
3974
3975                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3976                             ((p->score &&
3977                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3978                              (!p->score &&
3979                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3980                            ((p->status != DIFF_STATUS_MODIFIED) &&
3981                             strchr(filter, p->status)))
3982                                diff_q(&outq, p);
3983                        else
3984                                diff_free_filepair(p);
3985                }
3986        }
3987        free(q->queue);
3988        *q = outq;
3989}
3990
3991/* Check whether two filespecs with the same mode and size are identical */
3992static int diff_filespec_is_identical(struct diff_filespec *one,
3993                                      struct diff_filespec *two)
3994{
3995        if (S_ISGITLINK(one->mode))
3996                return 0;
3997        if (diff_populate_filespec(one, 0))
3998                return 0;
3999        if (diff_populate_filespec(two, 0))
4000                return 0;
4001        return !memcmp(one->data, two->data, one->size);
4002}
4003
4004static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
4005{
4006        int i;
4007        struct diff_queue_struct *q = &diff_queued_diff;
4008        struct diff_queue_struct outq;
4009        DIFF_QUEUE_CLEAR(&outq);
4010
4011        for (i = 0; i < q->nr; i++) {
4012                struct diff_filepair *p = q->queue[i];
4013
4014                /*
4015                 * 1. Entries that come from stat info dirtiness
4016                 *    always have both sides (iow, not create/delete),
4017                 *    one side of the object name is unknown, with
4018                 *    the same mode and size.  Keep the ones that
4019                 *    do not match these criteria.  They have real
4020                 *    differences.
4021                 *
4022                 * 2. At this point, the file is known to be modified,
4023                 *    with the same mode and size, and the object
4024                 *    name of one side is unknown.  Need to inspect
4025                 *    the identical contents.
4026                 */
4027                if (!DIFF_FILE_VALID(p->one) || /* (1) */
4028                    !DIFF_FILE_VALID(p->two) ||
4029                    (p->one->sha1_valid && p->two->sha1_valid) ||
4030                    (p->one->mode != p->two->mode) ||
4031                    diff_populate_filespec(p->one, 1) ||
4032                    diff_populate_filespec(p->two, 1) ||
4033                    (p->one->size != p->two->size) ||
4034                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
4035                        diff_q(&outq, p);
4036                else {
4037                        /*
4038                         * The caller can subtract 1 from skip_stat_unmatch
4039                         * to determine how many paths were dirty only
4040                         * due to stat info mismatch.
4041                         */
4042                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
4043                                diffopt->skip_stat_unmatch++;
4044                        diff_free_filepair(p);
4045                }
4046        }
4047        free(q->queue);
4048        *q = outq;
4049}
4050
4051static int diffnamecmp(const void *a_, const void *b_)
4052{
4053        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
4054        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
4055        const char *name_a, *name_b;
4056
4057        name_a = a->one ? a->one->path : a->two->path;
4058        name_b = b->one ? b->one->path : b->two->path;
4059        return strcmp(name_a, name_b);
4060}
4061
4062void diffcore_fix_diff_index(struct diff_options *options)
4063{
4064        struct diff_queue_struct *q = &diff_queued_diff;
4065        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
4066}
4067
4068void diffcore_std(struct diff_options *options)
4069{
4070        if (options->skip_stat_unmatch)
4071                diffcore_skip_stat_unmatch(options);
4072        if (!options->found_follow) {
4073                /* See try_to_follow_renames() in tree-diff.c */
4074                if (options->break_opt != -1)
4075                        diffcore_break(options->break_opt);
4076                if (options->detect_rename)
4077                        diffcore_rename(options);
4078                if (options->break_opt != -1)
4079                        diffcore_merge_broken();
4080        }
4081        if (options->pickaxe)
4082                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
4083        if (options->orderfile)
4084                diffcore_order(options->orderfile);
4085        if (!options->found_follow)
4086                /* See try_to_follow_renames() in tree-diff.c */
4087                diff_resolve_rename_copy();
4088        diffcore_apply_filter(options->filter);
4089
4090        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4091                DIFF_OPT_SET(options, HAS_CHANGES);
4092        else
4093                DIFF_OPT_CLR(options, HAS_CHANGES);
4094
4095        options->found_follow = 0;
4096}
4097
4098int diff_result_code(struct diff_options *opt, int status)
4099{
4100        int result = 0;
4101        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4102            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
4103                return status;
4104        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
4105            DIFF_OPT_TST(opt, HAS_CHANGES))
4106                result |= 01;
4107        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
4108            DIFF_OPT_TST(opt, CHECK_FAILED))
4109                result |= 02;
4110        return result;
4111}
4112
4113void diff_addremove(struct diff_options *options,
4114                    int addremove, unsigned mode,
4115                    const unsigned char *sha1,
4116                    const char *concatpath, unsigned dirty_submodule)
4117{
4118        struct diff_filespec *one, *two;
4119
4120        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
4121                return;
4122
4123        /* This may look odd, but it is a preparation for
4124         * feeding "there are unchanged files which should
4125         * not produce diffs, but when you are doing copy
4126         * detection you would need them, so here they are"
4127         * entries to the diff-core.  They will be prefixed
4128         * with something like '=' or '*' (I haven't decided
4129         * which but should not make any difference).
4130         * Feeding the same new and old to diff_change()
4131         * also has the same effect.
4132         * Before the final output happens, they are pruned after
4133         * merged into rename/copy pairs as appropriate.
4134         */
4135        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4136                addremove = (addremove == '+' ? '-' :
4137                             addremove == '-' ? '+' : addremove);
4138
4139        if (options->prefix &&
4140            strncmp(concatpath, options->prefix, options->prefix_length))
4141                return;
4142
4143        one = alloc_filespec(concatpath);
4144        two = alloc_filespec(concatpath);
4145
4146        if (addremove != '+')
4147                fill_filespec(one, sha1, mode);
4148        if (addremove != '-') {
4149                fill_filespec(two, sha1, mode);
4150                two->dirty_submodule = dirty_submodule;
4151        }
4152
4153        diff_queue(&diff_queued_diff, one, two);
4154        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4155                DIFF_OPT_SET(options, HAS_CHANGES);
4156}
4157
4158void diff_change(struct diff_options *options,
4159                 unsigned old_mode, unsigned new_mode,
4160                 const unsigned char *old_sha1,
4161                 const unsigned char *new_sha1,
4162                 const char *concatpath,
4163                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4164{
4165        struct diff_filespec *one, *two;
4166
4167        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
4168                        && S_ISGITLINK(new_mode))
4169                return;
4170
4171        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4172                unsigned tmp;
4173                const unsigned char *tmp_c;
4174                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4175                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4176                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4177                        new_dirty_submodule = tmp;
4178        }
4179
4180        if (options->prefix &&
4181            strncmp(concatpath, options->prefix, options->prefix_length))
4182                return;
4183
4184        one = alloc_filespec(concatpath);
4185        two = alloc_filespec(concatpath);
4186        fill_filespec(one, old_sha1, old_mode);
4187        fill_filespec(two, new_sha1, new_mode);
4188        one->dirty_submodule = old_dirty_submodule;
4189        two->dirty_submodule = new_dirty_submodule;
4190
4191        diff_queue(&diff_queued_diff, one, two);
4192        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4193                DIFF_OPT_SET(options, HAS_CHANGES);
4194}
4195
4196void diff_unmerge(struct diff_options *options,
4197                  const char *path,
4198                  unsigned mode, const unsigned char *sha1)
4199{
4200        struct diff_filespec *one, *two;
4201
4202        if (options->prefix &&
4203            strncmp(path, options->prefix, options->prefix_length))
4204                return;
4205
4206        one = alloc_filespec(path);
4207        two = alloc_filespec(path);
4208        fill_filespec(one, sha1, mode);
4209        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4210}
4211
4212static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4213                size_t *outsize)
4214{
4215        struct diff_tempfile *temp;
4216        const char *argv[3];
4217        const char **arg = argv;
4218        struct child_process child;
4219        struct strbuf buf = STRBUF_INIT;
4220        int err = 0;
4221
4222        temp = prepare_temp_file(spec->path, spec);
4223        *arg++ = pgm;
4224        *arg++ = temp->name;
4225        *arg = NULL;
4226
4227        memset(&child, 0, sizeof(child));
4228        child.use_shell = 1;
4229        child.argv = argv;
4230        child.out = -1;
4231        if (start_command(&child)) {
4232                remove_tempfile();
4233                return NULL;
4234        }
4235
4236        if (strbuf_read(&buf, child.out, 0) < 0)
4237                err = error("error reading from textconv command '%s'", pgm);
4238        close(child.out);
4239
4240        if (finish_command(&child) || err) {
4241                strbuf_release(&buf);
4242                remove_tempfile();
4243                return NULL;
4244        }
4245        remove_tempfile();
4246
4247        return strbuf_detach(&buf, outsize);
4248}
4249
4250size_t fill_textconv(struct userdiff_driver *driver,
4251                     struct diff_filespec *df,
4252                     char **outbuf)
4253{
4254        size_t size;
4255
4256        if (!driver || !driver->textconv) {
4257                if (!DIFF_FILE_VALID(df)) {
4258                        *outbuf = "";
4259                        return 0;
4260                }
4261                if (diff_populate_filespec(df, 0))
4262                        die("unable to read files to diff");
4263                *outbuf = df->data;
4264                return df->size;
4265        }
4266
4267        if (driver->textconv_cache) {
4268                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4269                                          &size);
4270                if (*outbuf)
4271                        return size;
4272        }
4273
4274        *outbuf = run_textconv(driver->textconv, df, &size);
4275        if (!*outbuf)
4276                die("unable to read files to diff");
4277
4278        if (driver->textconv_cache) {
4279                /* ignore errors, as we might be in a readonly repository */
4280                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4281                                size);
4282                /*
4283                 * we could save up changes and flush them all at the end,
4284                 * but we would need an extra call after all diffing is done.
4285                 * Since generating a cache entry is the slow path anyway,
4286                 * this extra overhead probably isn't a big deal.
4287                 */
4288                notes_cache_write(driver->textconv_cache);
4289        }
4290
4291        return size;
4292}