2a1482aa9036cd033868108f7ac67ccffd2df688
   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;
  33
  34static char diff_colors[][COLOR_MAXLEN] = {
  35        GIT_COLOR_RESET,
  36        GIT_COLOR_NORMAL,       /* PLAIN */
  37        GIT_COLOR_BOLD,         /* METAINFO */
  38        GIT_COLOR_CYAN,         /* FRAGINFO */
  39        GIT_COLOR_RED,          /* OLD */
  40        GIT_COLOR_GREEN,        /* NEW */
  41        GIT_COLOR_YELLOW,       /* COMMIT */
  42        GIT_COLOR_BG_RED,       /* WHITESPACE */
  43        GIT_COLOR_NORMAL,       /* FUNCINFO */
  44};
  45
  46static void diff_filespec_load_driver(struct diff_filespec *one);
  47static size_t fill_textconv(struct userdiff_driver *driver,
  48                            struct diff_filespec *df, char **outbuf);
  49
  50static int parse_diff_color_slot(const char *var, int ofs)
  51{
  52        if (!strcasecmp(var+ofs, "plain"))
  53                return DIFF_PLAIN;
  54        if (!strcasecmp(var+ofs, "meta"))
  55                return DIFF_METAINFO;
  56        if (!strcasecmp(var+ofs, "frag"))
  57                return DIFF_FRAGINFO;
  58        if (!strcasecmp(var+ofs, "old"))
  59                return DIFF_FILE_OLD;
  60        if (!strcasecmp(var+ofs, "new"))
  61                return DIFF_FILE_NEW;
  62        if (!strcasecmp(var+ofs, "commit"))
  63                return DIFF_COMMIT;
  64        if (!strcasecmp(var+ofs, "whitespace"))
  65                return DIFF_WHITESPACE;
  66        if (!strcasecmp(var+ofs, "func"))
  67                return DIFF_FUNCINFO;
  68        return -1;
  69}
  70
  71static int git_config_rename(const char *var, const char *value)
  72{
  73        if (!value)
  74                return DIFF_DETECT_RENAME;
  75        if (!strcasecmp(value, "copies") || !strcasecmp(value, "copy"))
  76                return  DIFF_DETECT_COPY;
  77        return git_config_bool(var,value) ? DIFF_DETECT_RENAME : 0;
  78}
  79
  80/*
  81 * These are to give UI layer defaults.
  82 * The core-level commands such as git-diff-files should
  83 * never be affected by the setting of diff.renames
  84 * the user happens to have in the configuration file.
  85 */
  86int git_diff_ui_config(const char *var, const char *value, void *cb)
  87{
  88        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  89                diff_use_color_default = git_config_colorbool(var, value, -1);
  90                return 0;
  91        }
  92        if (!strcmp(var, "diff.renames")) {
  93                diff_detect_rename_default = git_config_rename(var, value);
  94                return 0;
  95        }
  96        if (!strcmp(var, "diff.autorefreshindex")) {
  97                diff_auto_refresh_index = git_config_bool(var, value);
  98                return 0;
  99        }
 100        if (!strcmp(var, "diff.mnemonicprefix")) {
 101                diff_mnemonic_prefix = git_config_bool(var, value);
 102                return 0;
 103        }
 104        if (!strcmp(var, "diff.external"))
 105                return git_config_string(&external_diff_cmd_cfg, var, value);
 106        if (!strcmp(var, "diff.wordregex"))
 107                return git_config_string(&diff_word_regex_cfg, var, value);
 108
 109        return git_diff_basic_config(var, value, cb);
 110}
 111
 112int git_diff_basic_config(const char *var, const char *value, void *cb)
 113{
 114        if (!strcmp(var, "diff.renamelimit")) {
 115                diff_rename_limit_default = git_config_int(var, value);
 116                return 0;
 117        }
 118
 119        switch (userdiff_config(var, value)) {
 120                case 0: break;
 121                case -1: return -1;
 122                default: return 0;
 123        }
 124
 125        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 126                int slot = parse_diff_color_slot(var, 11);
 127                if (slot < 0)
 128                        return 0;
 129                if (!value)
 130                        return config_error_nonbool(var);
 131                color_parse(value, var, diff_colors[slot]);
 132                return 0;
 133        }
 134
 135        /* like GNU diff's --suppress-blank-empty option  */
 136        if (!strcmp(var, "diff.suppressblankempty") ||
 137                        /* for backwards compatibility */
 138                        !strcmp(var, "diff.suppress-blank-empty")) {
 139                diff_suppress_blank_empty = git_config_bool(var, value);
 140                return 0;
 141        }
 142
 143        return git_color_default_config(var, value, cb);
 144}
 145
 146static char *quote_two(const char *one, const char *two)
 147{
 148        int need_one = quote_c_style(one, NULL, NULL, 1);
 149        int need_two = quote_c_style(two, NULL, NULL, 1);
 150        struct strbuf res = STRBUF_INIT;
 151
 152        if (need_one + need_two) {
 153                strbuf_addch(&res, '"');
 154                quote_c_style(one, &res, NULL, 1);
 155                quote_c_style(two, &res, NULL, 1);
 156                strbuf_addch(&res, '"');
 157        } else {
 158                strbuf_addstr(&res, one);
 159                strbuf_addstr(&res, two);
 160        }
 161        return strbuf_detach(&res, NULL);
 162}
 163
 164static const char *external_diff(void)
 165{
 166        static const char *external_diff_cmd = NULL;
 167        static int done_preparing = 0;
 168
 169        if (done_preparing)
 170                return external_diff_cmd;
 171        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 172        if (!external_diff_cmd)
 173                external_diff_cmd = external_diff_cmd_cfg;
 174        done_preparing = 1;
 175        return external_diff_cmd;
 176}
 177
 178static struct diff_tempfile {
 179        const char *name; /* filename external diff should read from */
 180        char hex[41];
 181        char mode[10];
 182        char tmp_path[PATH_MAX];
 183} diff_temp[2];
 184
 185typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 186
 187struct emit_callback {
 188        int color_diff;
 189        unsigned ws_rule;
 190        int blank_at_eof_in_preimage;
 191        int blank_at_eof_in_postimage;
 192        int lno_in_preimage;
 193        int lno_in_postimage;
 194        sane_truncate_fn truncate;
 195        const char **label_path;
 196        struct diff_words_data *diff_words;
 197        struct diff_options *opt;
 198        int *found_changesp;
 199        struct strbuf *header;
 200};
 201
 202static int count_lines(const char *data, int size)
 203{
 204        int count, ch, completely_empty = 1, nl_just_seen = 0;
 205        count = 0;
 206        while (0 < size--) {
 207                ch = *data++;
 208                if (ch == '\n') {
 209                        count++;
 210                        nl_just_seen = 1;
 211                        completely_empty = 0;
 212                }
 213                else {
 214                        nl_just_seen = 0;
 215                        completely_empty = 0;
 216                }
 217        }
 218        if (completely_empty)
 219                return 0;
 220        if (!nl_just_seen)
 221                count++; /* no trailing newline */
 222        return count;
 223}
 224
 225static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 226{
 227        if (!DIFF_FILE_VALID(one)) {
 228                mf->ptr = (char *)""; /* does not matter */
 229                mf->size = 0;
 230                return 0;
 231        }
 232        else if (diff_populate_filespec(one, 0))
 233                return -1;
 234
 235        mf->ptr = one->data;
 236        mf->size = one->size;
 237        return 0;
 238}
 239
 240static int count_trailing_blank(mmfile_t *mf, unsigned ws_rule)
 241{
 242        char *ptr = mf->ptr;
 243        long size = mf->size;
 244        int cnt = 0;
 245
 246        if (!size)
 247                return cnt;
 248        ptr += size - 1; /* pointing at the very end */
 249        if (*ptr != '\n')
 250                ; /* incomplete line */
 251        else
 252                ptr--; /* skip the last LF */
 253        while (mf->ptr < ptr) {
 254                char *prev_eol;
 255                for (prev_eol = ptr; mf->ptr <= prev_eol; prev_eol--)
 256                        if (*prev_eol == '\n')
 257                                break;
 258                if (!ws_blank_line(prev_eol + 1, ptr - prev_eol, ws_rule))
 259                        break;
 260                cnt++;
 261                ptr = prev_eol - 1;
 262        }
 263        return cnt;
 264}
 265
 266static void check_blank_at_eof(mmfile_t *mf1, mmfile_t *mf2,
 267                               struct emit_callback *ecbdata)
 268{
 269        int l1, l2, at;
 270        unsigned ws_rule = ecbdata->ws_rule;
 271        l1 = count_trailing_blank(mf1, ws_rule);
 272        l2 = count_trailing_blank(mf2, ws_rule);
 273        if (l2 <= l1) {
 274                ecbdata->blank_at_eof_in_preimage = 0;
 275                ecbdata->blank_at_eof_in_postimage = 0;
 276                return;
 277        }
 278        at = count_lines(mf1->ptr, mf1->size);
 279        ecbdata->blank_at_eof_in_preimage = (at - l1) + 1;
 280
 281        at = count_lines(mf2->ptr, mf2->size);
 282        ecbdata->blank_at_eof_in_postimage = (at - l2) + 1;
 283}
 284
 285static void emit_line_0(struct diff_options *o, const char *set, const char *reset,
 286                        int first, const char *line, int len)
 287{
 288        int has_trailing_newline, has_trailing_carriage_return;
 289        int nofirst;
 290        FILE *file = o->file;
 291
 292        if (o->output_prefix) {
 293                struct strbuf *msg = NULL;
 294                msg = o->output_prefix(o, o->output_prefix_data);
 295                assert(msg);
 296                fwrite(msg->buf, msg->len, 1, file);
 297        }
 298
 299        if (len == 0) {
 300                has_trailing_newline = (first == '\n');
 301                has_trailing_carriage_return = (!has_trailing_newline &&
 302                                                (first == '\r'));
 303                nofirst = has_trailing_newline || has_trailing_carriage_return;
 304        } else {
 305                has_trailing_newline = (len > 0 && line[len-1] == '\n');
 306                if (has_trailing_newline)
 307                        len--;
 308                has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 309                if (has_trailing_carriage_return)
 310                        len--;
 311                nofirst = 0;
 312        }
 313
 314        if (len || !nofirst) {
 315                fputs(set, file);
 316                if (!nofirst)
 317                        fputc(first, file);
 318                fwrite(line, len, 1, file);
 319                fputs(reset, file);
 320        }
 321        if (has_trailing_carriage_return)
 322                fputc('\r', file);
 323        if (has_trailing_newline)
 324                fputc('\n', file);
 325}
 326
 327static void emit_line(struct diff_options *o, const char *set, const char *reset,
 328                      const char *line, int len)
 329{
 330        emit_line_0(o, set, reset, line[0], line+1, len-1);
 331}
 332
 333static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
 334{
 335        if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
 336              ecbdata->blank_at_eof_in_preimage &&
 337              ecbdata->blank_at_eof_in_postimage &&
 338              ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
 339              ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
 340                return 0;
 341        return ws_blank_line(line, len, ecbdata->ws_rule);
 342}
 343
 344static void emit_add_line(const char *reset,
 345                          struct emit_callback *ecbdata,
 346                          const char *line, int len)
 347{
 348        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 349        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 350
 351        if (!*ws)
 352                emit_line_0(ecbdata->opt, set, reset, '+', line, len);
 353        else if (new_blank_line_at_eof(ecbdata, line, len))
 354                /* Blank line at EOF - paint '+' as well */
 355                emit_line_0(ecbdata->opt, ws, reset, '+', line, len);
 356        else {
 357                /* Emit just the prefix, then the rest. */
 358                emit_line_0(ecbdata->opt, set, reset, '+', "", 0);
 359                ws_check_emit(line, len, ecbdata->ws_rule,
 360                              ecbdata->opt->file, set, reset, ws);
 361        }
 362}
 363
 364static void emit_hunk_header(struct emit_callback *ecbdata,
 365                             const char *line, int len)
 366{
 367        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 368        const char *frag = diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO);
 369        const char *func = diff_get_color(ecbdata->color_diff, DIFF_FUNCINFO);
 370        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 371        static const char atat[2] = { '@', '@' };
 372        const char *cp, *ep;
 373        struct strbuf msgbuf = STRBUF_INIT;
 374        int org_len = len;
 375        int i = 1;
 376
 377        /*
 378         * As a hunk header must begin with "@@ -<old>, +<new> @@",
 379         * it always is at least 10 bytes long.
 380         */
 381        if (len < 10 ||
 382            memcmp(line, atat, 2) ||
 383            !(ep = memmem(line + 2, len - 2, atat, 2))) {
 384                emit_line(ecbdata->opt, plain, reset, line, len);
 385                return;
 386        }
 387        ep += 2; /* skip over @@ */
 388
 389        /* The hunk header in fraginfo color */
 390        strbuf_add(&msgbuf, frag, strlen(frag));
 391        strbuf_add(&msgbuf, line, ep - line);
 392        strbuf_add(&msgbuf, reset, strlen(reset));
 393
 394        /*
 395         * trailing "\r\n"
 396         */
 397        for ( ; i < 3; i++)
 398                if (line[len - i] == '\r' || line[len - i] == '\n')
 399                        len--;
 400
 401        /* blank before the func header */
 402        for (cp = ep; ep - line < len; ep++)
 403                if (*ep != ' ' && *ep != '\t')
 404                        break;
 405        if (ep != cp) {
 406                strbuf_add(&msgbuf, plain, strlen(plain));
 407                strbuf_add(&msgbuf, cp, ep - cp);
 408                strbuf_add(&msgbuf, reset, strlen(reset));
 409        }
 410
 411        if (ep < line + len) {
 412                strbuf_add(&msgbuf, func, strlen(func));
 413                strbuf_add(&msgbuf, ep, line + len - ep);
 414                strbuf_add(&msgbuf, reset, strlen(reset));
 415        }
 416
 417        strbuf_add(&msgbuf, line + len, org_len - len);
 418        emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
 419        strbuf_release(&msgbuf);
 420}
 421
 422static struct diff_tempfile *claim_diff_tempfile(void) {
 423        int i;
 424        for (i = 0; i < ARRAY_SIZE(diff_temp); i++)
 425                if (!diff_temp[i].name)
 426                        return diff_temp + i;
 427        die("BUG: diff is failing to clean up its tempfiles");
 428}
 429
 430static int remove_tempfile_installed;
 431
 432static void remove_tempfile(void)
 433{
 434        int i;
 435        for (i = 0; i < ARRAY_SIZE(diff_temp); i++) {
 436                if (diff_temp[i].name == diff_temp[i].tmp_path)
 437                        unlink_or_warn(diff_temp[i].name);
 438                diff_temp[i].name = NULL;
 439        }
 440}
 441
 442static void remove_tempfile_on_signal(int signo)
 443{
 444        remove_tempfile();
 445        sigchain_pop(signo);
 446        raise(signo);
 447}
 448
 449static void print_line_count(FILE *file, int count)
 450{
 451        switch (count) {
 452        case 0:
 453                fprintf(file, "0,0");
 454                break;
 455        case 1:
 456                fprintf(file, "1");
 457                break;
 458        default:
 459                fprintf(file, "1,%d", count);
 460                break;
 461        }
 462}
 463
 464static void emit_rewrite_lines(struct emit_callback *ecb,
 465                               int prefix, const char *data, int size)
 466{
 467        const char *endp = NULL;
 468        static const char *nneof = " No newline at end of file\n";
 469        const char *old = diff_get_color(ecb->color_diff, DIFF_FILE_OLD);
 470        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 471
 472        while (0 < size) {
 473                int len;
 474
 475                endp = memchr(data, '\n', size);
 476                len = endp ? (endp - data + 1) : size;
 477                if (prefix != '+') {
 478                        ecb->lno_in_preimage++;
 479                        emit_line_0(ecb->opt, old, reset, '-',
 480                                    data, len);
 481                } else {
 482                        ecb->lno_in_postimage++;
 483                        emit_add_line(reset, ecb, data, len);
 484                }
 485                size -= len;
 486                data += len;
 487        }
 488        if (!endp) {
 489                const char *plain = diff_get_color(ecb->color_diff,
 490                                                   DIFF_PLAIN);
 491                emit_line_0(ecb->opt, plain, reset, '\\',
 492                            nneof, strlen(nneof));
 493        }
 494}
 495
 496static void emit_rewrite_diff(const char *name_a,
 497                              const char *name_b,
 498                              struct diff_filespec *one,
 499                              struct diff_filespec *two,
 500                              struct userdiff_driver *textconv_one,
 501                              struct userdiff_driver *textconv_two,
 502                              struct diff_options *o)
 503{
 504        int lc_a, lc_b;
 505        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 506        const char *name_a_tab, *name_b_tab;
 507        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 508        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 509        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 510        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 511        const char *a_prefix, *b_prefix;
 512        char *data_one, *data_two;
 513        size_t size_one, size_two;
 514        struct emit_callback ecbdata;
 515        char *line_prefix = "";
 516        struct strbuf *msgbuf;
 517
 518        if (o && o->output_prefix) {
 519                msgbuf = o->output_prefix(o, o->output_prefix_data);
 520                line_prefix = msgbuf->buf;
 521        }
 522
 523        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 524                a_prefix = o->b_prefix;
 525                b_prefix = o->a_prefix;
 526        } else {
 527                a_prefix = o->a_prefix;
 528                b_prefix = o->b_prefix;
 529        }
 530
 531        name_a += (*name_a == '/');
 532        name_b += (*name_b == '/');
 533        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 534        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 535
 536        strbuf_reset(&a_name);
 537        strbuf_reset(&b_name);
 538        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 539        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 540
 541        size_one = fill_textconv(textconv_one, one, &data_one);
 542        size_two = fill_textconv(textconv_two, two, &data_two);
 543
 544        memset(&ecbdata, 0, sizeof(ecbdata));
 545        ecbdata.color_diff = color_diff;
 546        ecbdata.found_changesp = &o->found_changes;
 547        ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 548        ecbdata.opt = o;
 549        if (ecbdata.ws_rule & WS_BLANK_AT_EOF) {
 550                mmfile_t mf1, mf2;
 551                mf1.ptr = (char *)data_one;
 552                mf2.ptr = (char *)data_two;
 553                mf1.size = size_one;
 554                mf2.size = size_two;
 555                check_blank_at_eof(&mf1, &mf2, &ecbdata);
 556        }
 557        ecbdata.lno_in_preimage = 1;
 558        ecbdata.lno_in_postimage = 1;
 559
 560        lc_a = count_lines(data_one, size_one);
 561        lc_b = count_lines(data_two, size_two);
 562        fprintf(o->file,
 563                "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
 564                line_prefix, metainfo, a_name.buf, name_a_tab, reset,
 565                line_prefix, metainfo, b_name.buf, name_b_tab, reset,
 566                line_prefix, fraginfo);
 567        print_line_count(o->file, lc_a);
 568        fprintf(o->file, " +");
 569        print_line_count(o->file, lc_b);
 570        fprintf(o->file, " @@%s\n", reset);
 571        if (lc_a)
 572                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
 573        if (lc_b)
 574                emit_rewrite_lines(&ecbdata, '+', data_two, size_two);
 575        if (textconv_one)
 576                free((char *)data_one);
 577        if (textconv_two)
 578                free((char *)data_two);
 579}
 580
 581struct diff_words_buffer {
 582        mmfile_t text;
 583        long alloc;
 584        struct diff_words_orig {
 585                const char *begin, *end;
 586        } *orig;
 587        int orig_nr, orig_alloc;
 588};
 589
 590static void diff_words_append(char *line, unsigned long len,
 591                struct diff_words_buffer *buffer)
 592{
 593        ALLOC_GROW(buffer->text.ptr, buffer->text.size + len, buffer->alloc);
 594        line++;
 595        len--;
 596        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 597        buffer->text.size += len;
 598        buffer->text.ptr[buffer->text.size] = '\0';
 599}
 600
 601struct diff_words_style_elem
 602{
 603        const char *prefix;
 604        const char *suffix;
 605        const char *color; /* NULL; filled in by the setup code if
 606                            * color is enabled */
 607};
 608
 609struct diff_words_style
 610{
 611        enum diff_words_type type;
 612        struct diff_words_style_elem new, old, ctx;
 613        const char *newline;
 614};
 615
 616struct diff_words_style diff_words_styles[] = {
 617        { DIFF_WORDS_PORCELAIN, {"+", "\n"}, {"-", "\n"}, {" ", "\n"}, "~\n" },
 618        { DIFF_WORDS_PLAIN, {"{+", "+}"}, {"[-", "-]"}, {"", ""}, "\n" },
 619        { DIFF_WORDS_COLOR, {"", ""}, {"", ""}, {"", ""}, "\n" }
 620};
 621
 622struct diff_words_data {
 623        struct diff_words_buffer minus, plus;
 624        const char *current_plus;
 625        FILE *file;
 626        regex_t *word_regex;
 627        enum diff_words_type type;
 628        struct diff_words_style *style;
 629};
 630
 631static int fn_out_diff_words_write_helper(FILE *fp,
 632                                          struct diff_words_style_elem *st_el,
 633                                          const char *newline,
 634                                          size_t count, const char *buf)
 635{
 636        while (count) {
 637                char *p = memchr(buf, '\n', count);
 638                if (p != buf) {
 639                        if (st_el->color && fputs(st_el->color, fp) < 0)
 640                                return -1;
 641                        if (fputs(st_el->prefix, fp) < 0 ||
 642                            fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
 643                            fputs(st_el->suffix, fp) < 0)
 644                                return -1;
 645                        if (st_el->color && *st_el->color
 646                            && fputs(GIT_COLOR_RESET, fp) < 0)
 647                                return -1;
 648                }
 649                if (!p)
 650                        return 0;
 651                if (fputs(newline, fp) < 0)
 652                        return -1;
 653                count -= p + 1 - buf;
 654                buf = p + 1;
 655        }
 656        return 0;
 657}
 658
 659static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 660{
 661        struct diff_words_data *diff_words = priv;
 662        struct diff_words_style *style = diff_words->style;
 663        int minus_first, minus_len, plus_first, plus_len;
 664        const char *minus_begin, *minus_end, *plus_begin, *plus_end;
 665
 666        if (line[0] != '@' || parse_hunk_header(line, len,
 667                        &minus_first, &minus_len, &plus_first, &plus_len))
 668                return;
 669
 670        /* POSIX requires that first be decremented by one if len == 0... */
 671        if (minus_len) {
 672                minus_begin = diff_words->minus.orig[minus_first].begin;
 673                minus_end =
 674                        diff_words->minus.orig[minus_first + minus_len - 1].end;
 675        } else
 676                minus_begin = minus_end =
 677                        diff_words->minus.orig[minus_first].end;
 678
 679        if (plus_len) {
 680                plus_begin = diff_words->plus.orig[plus_first].begin;
 681                plus_end = diff_words->plus.orig[plus_first + plus_len - 1].end;
 682        } else
 683                plus_begin = plus_end = diff_words->plus.orig[plus_first].end;
 684
 685        if (diff_words->current_plus != plus_begin)
 686                fn_out_diff_words_write_helper(diff_words->file,
 687                                &style->ctx, style->newline,
 688                                plus_begin - diff_words->current_plus,
 689                                diff_words->current_plus);
 690        if (minus_begin != minus_end)
 691                fn_out_diff_words_write_helper(diff_words->file,
 692                                &style->old, style->newline,
 693                                minus_end - minus_begin, minus_begin);
 694        if (plus_begin != plus_end)
 695                fn_out_diff_words_write_helper(diff_words->file,
 696                                &style->new, style->newline,
 697                                plus_end - plus_begin, plus_begin);
 698
 699        diff_words->current_plus = plus_end;
 700}
 701
 702/* This function starts looking at *begin, and returns 0 iff a word was found. */
 703static int find_word_boundaries(mmfile_t *buffer, regex_t *word_regex,
 704                int *begin, int *end)
 705{
 706        if (word_regex && *begin < buffer->size) {
 707                regmatch_t match[1];
 708                if (!regexec(word_regex, buffer->ptr + *begin, 1, match, 0)) {
 709                        char *p = memchr(buffer->ptr + *begin + match[0].rm_so,
 710                                        '\n', match[0].rm_eo - match[0].rm_so);
 711                        *end = p ? p - buffer->ptr : match[0].rm_eo + *begin;
 712                        *begin += match[0].rm_so;
 713                        return *begin >= *end;
 714                }
 715                return -1;
 716        }
 717
 718        /* find the next word */
 719        while (*begin < buffer->size && isspace(buffer->ptr[*begin]))
 720                (*begin)++;
 721        if (*begin >= buffer->size)
 722                return -1;
 723
 724        /* find the end of the word */
 725        *end = *begin + 1;
 726        while (*end < buffer->size && !isspace(buffer->ptr[*end]))
 727                (*end)++;
 728
 729        return 0;
 730}
 731
 732/*
 733 * This function splits the words in buffer->text, stores the list with
 734 * newline separator into out, and saves the offsets of the original words
 735 * in buffer->orig.
 736 */
 737static void diff_words_fill(struct diff_words_buffer *buffer, mmfile_t *out,
 738                regex_t *word_regex)
 739{
 740        int i, j;
 741        long alloc = 0;
 742
 743        out->size = 0;
 744        out->ptr = NULL;
 745
 746        /* fake an empty "0th" word */
 747        ALLOC_GROW(buffer->orig, 1, buffer->orig_alloc);
 748        buffer->orig[0].begin = buffer->orig[0].end = buffer->text.ptr;
 749        buffer->orig_nr = 1;
 750
 751        for (i = 0; i < buffer->text.size; i++) {
 752                if (find_word_boundaries(&buffer->text, word_regex, &i, &j))
 753                        return;
 754
 755                /* store original boundaries */
 756                ALLOC_GROW(buffer->orig, buffer->orig_nr + 1,
 757                                buffer->orig_alloc);
 758                buffer->orig[buffer->orig_nr].begin = buffer->text.ptr + i;
 759                buffer->orig[buffer->orig_nr].end = buffer->text.ptr + j;
 760                buffer->orig_nr++;
 761
 762                /* store one word */
 763                ALLOC_GROW(out->ptr, out->size + j - i + 1, alloc);
 764                memcpy(out->ptr + out->size, buffer->text.ptr + i, j - i);
 765                out->ptr[out->size + j - i] = '\n';
 766                out->size += j - i + 1;
 767
 768                i = j - 1;
 769        }
 770}
 771
 772/* this executes the word diff on the accumulated buffers */
 773static void diff_words_show(struct diff_words_data *diff_words)
 774{
 775        xpparam_t xpp;
 776        xdemitconf_t xecfg;
 777        mmfile_t minus, plus;
 778        struct diff_words_style *style = diff_words->style;
 779
 780        /* special case: only removal */
 781        if (!diff_words->plus.text.size) {
 782                fn_out_diff_words_write_helper(diff_words->file,
 783                        &style->old, style->newline,
 784                        diff_words->minus.text.size, diff_words->minus.text.ptr);
 785                diff_words->minus.text.size = 0;
 786                return;
 787        }
 788
 789        diff_words->current_plus = diff_words->plus.text.ptr;
 790
 791        memset(&xpp, 0, sizeof(xpp));
 792        memset(&xecfg, 0, sizeof(xecfg));
 793        diff_words_fill(&diff_words->minus, &minus, diff_words->word_regex);
 794        diff_words_fill(&diff_words->plus, &plus, diff_words->word_regex);
 795        xpp.flags = XDF_NEED_MINIMAL;
 796        /* as only the hunk header will be parsed, we need a 0-context */
 797        xecfg.ctxlen = 0;
 798        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 799                      &xpp, &xecfg);
 800        free(minus.ptr);
 801        free(plus.ptr);
 802        if (diff_words->current_plus != diff_words->plus.text.ptr +
 803                        diff_words->plus.text.size)
 804                fn_out_diff_words_write_helper(diff_words->file,
 805                        &style->ctx, style->newline,
 806                        diff_words->plus.text.ptr + diff_words->plus.text.size
 807                        - diff_words->current_plus, diff_words->current_plus);
 808        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 809}
 810
 811/* In "color-words" mode, show word-diff of words accumulated in the buffer */
 812static void diff_words_flush(struct emit_callback *ecbdata)
 813{
 814        if (ecbdata->diff_words->minus.text.size ||
 815            ecbdata->diff_words->plus.text.size)
 816                diff_words_show(ecbdata->diff_words);
 817}
 818
 819static void free_diff_words_data(struct emit_callback *ecbdata)
 820{
 821        if (ecbdata->diff_words) {
 822                diff_words_flush(ecbdata);
 823                free (ecbdata->diff_words->minus.text.ptr);
 824                free (ecbdata->diff_words->minus.orig);
 825                free (ecbdata->diff_words->plus.text.ptr);
 826                free (ecbdata->diff_words->plus.orig);
 827                free(ecbdata->diff_words->word_regex);
 828                free(ecbdata->diff_words);
 829                ecbdata->diff_words = NULL;
 830        }
 831}
 832
 833const char *diff_get_color(int diff_use_color, enum color_diff ix)
 834{
 835        if (diff_use_color)
 836                return diff_colors[ix];
 837        return "";
 838}
 839
 840static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 841{
 842        const char *cp;
 843        unsigned long allot;
 844        size_t l = len;
 845
 846        if (ecb->truncate)
 847                return ecb->truncate(line, len);
 848        cp = line;
 849        allot = l;
 850        while (0 < l) {
 851                (void) utf8_width(&cp, &l);
 852                if (!cp)
 853                        break; /* truncated in the middle? */
 854        }
 855        return allot - l;
 856}
 857
 858static void find_lno(const char *line, struct emit_callback *ecbdata)
 859{
 860        const char *p;
 861        ecbdata->lno_in_preimage = 0;
 862        ecbdata->lno_in_postimage = 0;
 863        p = strchr(line, '-');
 864        if (!p)
 865                return; /* cannot happen */
 866        ecbdata->lno_in_preimage = strtol(p + 1, NULL, 10);
 867        p = strchr(p, '+');
 868        if (!p)
 869                return; /* cannot happen */
 870        ecbdata->lno_in_postimage = strtol(p + 1, NULL, 10);
 871}
 872
 873static void fn_out_consume(void *priv, char *line, unsigned long len)
 874{
 875        struct emit_callback *ecbdata = priv;
 876        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 877        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 878        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 879        struct diff_options *o = ecbdata->opt;
 880        char *line_prefix = "";
 881        struct strbuf *msgbuf;
 882
 883        if (o && o->output_prefix) {
 884                msgbuf = o->output_prefix(o, o->output_prefix_data);
 885                line_prefix = msgbuf->buf;
 886        }
 887
 888        if (ecbdata->header) {
 889                fprintf(ecbdata->opt->file, "%s", ecbdata->header->buf);
 890                strbuf_reset(ecbdata->header);
 891                ecbdata->header = NULL;
 892        }
 893        *(ecbdata->found_changesp) = 1;
 894
 895        if (ecbdata->label_path[0]) {
 896                const char *name_a_tab, *name_b_tab;
 897
 898                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 899                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 900
 901                fprintf(ecbdata->opt->file, "%s%s--- %s%s%s\n",
 902                        line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
 903                fprintf(ecbdata->opt->file, "%s%s+++ %s%s%s\n",
 904                        line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
 905                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 906        }
 907
 908        if (diff_suppress_blank_empty
 909            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 910                line[0] = '\n';
 911                len = 1;
 912        }
 913
 914        if (line[0] == '@') {
 915                if (ecbdata->diff_words)
 916                        diff_words_flush(ecbdata);
 917                len = sane_truncate_line(ecbdata, line, len);
 918                find_lno(line, ecbdata);
 919                emit_hunk_header(ecbdata, line, len);
 920                if (line[len-1] != '\n')
 921                        putc('\n', ecbdata->opt->file);
 922                return;
 923        }
 924
 925        if (len < 1) {
 926                emit_line(ecbdata->opt, reset, reset, line, len);
 927                if (ecbdata->diff_words
 928                    && ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN)
 929                        fputs("~\n", ecbdata->opt->file);
 930                return;
 931        }
 932
 933        if (ecbdata->diff_words) {
 934                if (line[0] == '-') {
 935                        diff_words_append(line, len,
 936                                          &ecbdata->diff_words->minus);
 937                        return;
 938                } else if (line[0] == '+') {
 939                        diff_words_append(line, len,
 940                                          &ecbdata->diff_words->plus);
 941                        return;
 942                }
 943                diff_words_flush(ecbdata);
 944                if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
 945                        emit_line(ecbdata->opt, plain, reset, line, len);
 946                        fputs("~\n", ecbdata->opt->file);
 947                } else {
 948                        /* don't print the prefix character */
 949                        emit_line(ecbdata->opt, plain, reset, line+1, len-1);
 950                }
 951                return;
 952        }
 953
 954        if (line[0] != '+') {
 955                const char *color =
 956                        diff_get_color(ecbdata->color_diff,
 957                                       line[0] == '-' ? DIFF_FILE_OLD : DIFF_PLAIN);
 958                ecbdata->lno_in_preimage++;
 959                if (line[0] == ' ')
 960                        ecbdata->lno_in_postimage++;
 961                emit_line(ecbdata->opt, color, reset, line, len);
 962        } else {
 963                ecbdata->lno_in_postimage++;
 964                emit_add_line(reset, ecbdata, line + 1, len - 1);
 965        }
 966}
 967
 968static char *pprint_rename(const char *a, const char *b)
 969{
 970        const char *old = a;
 971        const char *new = b;
 972        struct strbuf name = STRBUF_INIT;
 973        int pfx_length, sfx_length;
 974        int len_a = strlen(a);
 975        int len_b = strlen(b);
 976        int a_midlen, b_midlen;
 977        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 978        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 979
 980        if (qlen_a || qlen_b) {
 981                quote_c_style(a, &name, NULL, 0);
 982                strbuf_addstr(&name, " => ");
 983                quote_c_style(b, &name, NULL, 0);
 984                return strbuf_detach(&name, NULL);
 985        }
 986
 987        /* Find common prefix */
 988        pfx_length = 0;
 989        while (*old && *new && *old == *new) {
 990                if (*old == '/')
 991                        pfx_length = old - a + 1;
 992                old++;
 993                new++;
 994        }
 995
 996        /* Find common suffix */
 997        old = a + len_a;
 998        new = b + len_b;
 999        sfx_length = 0;
1000        while (a <= old && b <= new && *old == *new) {
1001                if (*old == '/')
1002                        sfx_length = len_a - (old - a);
1003                old--;
1004                new--;
1005        }
1006
1007        /*
1008         * pfx{mid-a => mid-b}sfx
1009         * {pfx-a => pfx-b}sfx
1010         * pfx{sfx-a => sfx-b}
1011         * name-a => name-b
1012         */
1013        a_midlen = len_a - pfx_length - sfx_length;
1014        b_midlen = len_b - pfx_length - sfx_length;
1015        if (a_midlen < 0)
1016                a_midlen = 0;
1017        if (b_midlen < 0)
1018                b_midlen = 0;
1019
1020        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
1021        if (pfx_length + sfx_length) {
1022                strbuf_add(&name, a, pfx_length);
1023                strbuf_addch(&name, '{');
1024        }
1025        strbuf_add(&name, a + pfx_length, a_midlen);
1026        strbuf_addstr(&name, " => ");
1027        strbuf_add(&name, b + pfx_length, b_midlen);
1028        if (pfx_length + sfx_length) {
1029                strbuf_addch(&name, '}');
1030                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
1031        }
1032        return strbuf_detach(&name, NULL);
1033}
1034
1035struct diffstat_t {
1036        int nr;
1037        int alloc;
1038        struct diffstat_file {
1039                char *from_name;
1040                char *name;
1041                char *print_name;
1042                unsigned is_unmerged:1;
1043                unsigned is_binary:1;
1044                unsigned is_renamed:1;
1045                uintmax_t added, deleted;
1046        } **files;
1047};
1048
1049static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
1050                                          const char *name_a,
1051                                          const char *name_b)
1052{
1053        struct diffstat_file *x;
1054        x = xcalloc(sizeof (*x), 1);
1055        if (diffstat->nr == diffstat->alloc) {
1056                diffstat->alloc = alloc_nr(diffstat->alloc);
1057                diffstat->files = xrealloc(diffstat->files,
1058                                diffstat->alloc * sizeof(x));
1059        }
1060        diffstat->files[diffstat->nr++] = x;
1061        if (name_b) {
1062                x->from_name = xstrdup(name_a);
1063                x->name = xstrdup(name_b);
1064                x->is_renamed = 1;
1065        }
1066        else {
1067                x->from_name = NULL;
1068                x->name = xstrdup(name_a);
1069        }
1070        return x;
1071}
1072
1073static void diffstat_consume(void *priv, char *line, unsigned long len)
1074{
1075        struct diffstat_t *diffstat = priv;
1076        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
1077
1078        if (line[0] == '+')
1079                x->added++;
1080        else if (line[0] == '-')
1081                x->deleted++;
1082}
1083
1084const char mime_boundary_leader[] = "------------";
1085
1086static int scale_linear(int it, int width, int max_change)
1087{
1088        /*
1089         * make sure that at least one '-' is printed if there were deletions,
1090         * and likewise for '+'.
1091         */
1092        if (max_change < 2)
1093                return it;
1094        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
1095}
1096
1097static void show_name(FILE *file,
1098                      const char *prefix, const char *name, int len)
1099{
1100        fprintf(file, " %s%-*s |", prefix, len, name);
1101}
1102
1103static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
1104{
1105        if (cnt <= 0)
1106                return;
1107        fprintf(file, "%s", set);
1108        while (cnt--)
1109                putc(ch, file);
1110        fprintf(file, "%s", reset);
1111}
1112
1113static void fill_print_name(struct diffstat_file *file)
1114{
1115        char *pname;
1116
1117        if (file->print_name)
1118                return;
1119
1120        if (!file->is_renamed) {
1121                struct strbuf buf = STRBUF_INIT;
1122                if (quote_c_style(file->name, &buf, NULL, 0)) {
1123                        pname = strbuf_detach(&buf, NULL);
1124                } else {
1125                        pname = file->name;
1126                        strbuf_release(&buf);
1127                }
1128        } else {
1129                pname = pprint_rename(file->from_name, file->name);
1130        }
1131        file->print_name = pname;
1132}
1133
1134static void show_stats(struct diffstat_t *data, struct diff_options *options)
1135{
1136        int i, len, add, del, adds = 0, dels = 0;
1137        uintmax_t max_change = 0, max_len = 0;
1138        int total_files = data->nr;
1139        int width, name_width;
1140        const char *reset, *set, *add_c, *del_c;
1141        const char *line_prefix = "";
1142        struct strbuf *msg = NULL;
1143
1144        if (data->nr == 0)
1145                return;
1146
1147        if (options->output_prefix) {
1148                msg = options->output_prefix(options, options->output_prefix_data);
1149                line_prefix = msg->buf;
1150        }
1151
1152        width = options->stat_width ? options->stat_width : 80;
1153        name_width = options->stat_name_width ? options->stat_name_width : 50;
1154
1155        /* Sanity: give at least 5 columns to the graph,
1156         * but leave at least 10 columns for the name.
1157         */
1158        if (width < 25)
1159                width = 25;
1160        if (name_width < 10)
1161                name_width = 10;
1162        else if (width < name_width + 15)
1163                name_width = width - 15;
1164
1165        /* Find the longest filename and max number of changes */
1166        reset = diff_get_color_opt(options, DIFF_RESET);
1167        set   = diff_get_color_opt(options, DIFF_PLAIN);
1168        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
1169        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
1170
1171        for (i = 0; i < data->nr; i++) {
1172                struct diffstat_file *file = data->files[i];
1173                uintmax_t change = file->added + file->deleted;
1174                fill_print_name(file);
1175                len = strlen(file->print_name);
1176                if (max_len < len)
1177                        max_len = len;
1178
1179                if (file->is_binary || file->is_unmerged)
1180                        continue;
1181                if (max_change < change)
1182                        max_change = change;
1183        }
1184
1185        /* Compute the width of the graph part;
1186         * 10 is for one blank at the beginning of the line plus
1187         * " | count " between the name and the graph.
1188         *
1189         * From here on, name_width is the width of the name area,
1190         * and width is the width of the graph area.
1191         */
1192        name_width = (name_width < max_len) ? name_width : max_len;
1193        if (width < (name_width + 10) + max_change)
1194                width = width - (name_width + 10);
1195        else
1196                width = max_change;
1197
1198        for (i = 0; i < data->nr; i++) {
1199                const char *prefix = "";
1200                char *name = data->files[i]->print_name;
1201                uintmax_t added = data->files[i]->added;
1202                uintmax_t deleted = data->files[i]->deleted;
1203                int name_len;
1204
1205                /*
1206                 * "scale" the filename
1207                 */
1208                len = name_width;
1209                name_len = strlen(name);
1210                if (name_width < name_len) {
1211                        char *slash;
1212                        prefix = "...";
1213                        len -= 3;
1214                        name += name_len - len;
1215                        slash = strchr(name, '/');
1216                        if (slash)
1217                                name = slash;
1218                }
1219
1220                if (data->files[i]->is_binary) {
1221                        fprintf(options->file, "%s", line_prefix);
1222                        show_name(options->file, prefix, name, len);
1223                        fprintf(options->file, "  Bin ");
1224                        fprintf(options->file, "%s%"PRIuMAX"%s",
1225                                del_c, deleted, reset);
1226                        fprintf(options->file, " -> ");
1227                        fprintf(options->file, "%s%"PRIuMAX"%s",
1228                                add_c, added, reset);
1229                        fprintf(options->file, " bytes");
1230                        fprintf(options->file, "\n");
1231                        continue;
1232                }
1233                else if (data->files[i]->is_unmerged) {
1234                        fprintf(options->file, "%s", line_prefix);
1235                        show_name(options->file, prefix, name, len);
1236                        fprintf(options->file, "  Unmerged\n");
1237                        continue;
1238                }
1239                else if (!data->files[i]->is_renamed &&
1240                         (added + deleted == 0)) {
1241                        total_files--;
1242                        continue;
1243                }
1244
1245                /*
1246                 * scale the add/delete
1247                 */
1248                add = added;
1249                del = deleted;
1250                adds += add;
1251                dels += del;
1252
1253                if (width <= max_change) {
1254                        add = scale_linear(add, width, max_change);
1255                        del = scale_linear(del, width, max_change);
1256                }
1257                fprintf(options->file, "%s", line_prefix);
1258                show_name(options->file, prefix, name, len);
1259                fprintf(options->file, "%5"PRIuMAX"%s", added + deleted,
1260                                added + deleted ? " " : "");
1261                show_graph(options->file, '+', add, add_c, reset);
1262                show_graph(options->file, '-', del, del_c, reset);
1263                fprintf(options->file, "\n");
1264        }
1265        fprintf(options->file, "%s", line_prefix);
1266        fprintf(options->file,
1267               " %d files changed, %d insertions(+), %d deletions(-)\n",
1268               total_files, adds, dels);
1269}
1270
1271static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
1272{
1273        int i, adds = 0, dels = 0, total_files = data->nr;
1274
1275        if (data->nr == 0)
1276                return;
1277
1278        for (i = 0; i < data->nr; i++) {
1279                if (!data->files[i]->is_binary &&
1280                    !data->files[i]->is_unmerged) {
1281                        int added = data->files[i]->added;
1282                        int deleted= data->files[i]->deleted;
1283                        if (!data->files[i]->is_renamed &&
1284                            (added + deleted == 0)) {
1285                                total_files--;
1286                        } else {
1287                                adds += added;
1288                                dels += deleted;
1289                        }
1290                }
1291        }
1292        if (options->output_prefix) {
1293                struct strbuf *msg = NULL;
1294                msg = options->output_prefix(options,
1295                                options->output_prefix_data);
1296                fprintf(options->file, "%s", msg->buf);
1297        }
1298        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
1299               total_files, adds, dels);
1300}
1301
1302static void show_numstat(struct diffstat_t *data, struct diff_options *options)
1303{
1304        int i;
1305
1306        if (data->nr == 0)
1307                return;
1308
1309        for (i = 0; i < data->nr; i++) {
1310                struct diffstat_file *file = data->files[i];
1311
1312                if (options->output_prefix) {
1313                        struct strbuf *msg = NULL;
1314                        msg = options->output_prefix(options,
1315                                        options->output_prefix_data);
1316                        fprintf(options->file, "%s", msg->buf);
1317                }
1318
1319                if (file->is_binary)
1320                        fprintf(options->file, "-\t-\t");
1321                else
1322                        fprintf(options->file,
1323                                "%"PRIuMAX"\t%"PRIuMAX"\t",
1324                                file->added, file->deleted);
1325                if (options->line_termination) {
1326                        fill_print_name(file);
1327                        if (!file->is_renamed)
1328                                write_name_quoted(file->name, options->file,
1329                                                  options->line_termination);
1330                        else {
1331                                fputs(file->print_name, options->file);
1332                                putc(options->line_termination, options->file);
1333                        }
1334                } else {
1335                        if (file->is_renamed) {
1336                                putc('\0', options->file);
1337                                write_name_quoted(file->from_name, options->file, '\0');
1338                        }
1339                        write_name_quoted(file->name, options->file, '\0');
1340                }
1341        }
1342}
1343
1344struct dirstat_file {
1345        const char *name;
1346        unsigned long changed;
1347};
1348
1349struct dirstat_dir {
1350        struct dirstat_file *files;
1351        int alloc, nr, percent, cumulative;
1352};
1353
1354static long gather_dirstat(struct diff_options *opt, struct dirstat_dir *dir,
1355                unsigned long changed, const char *base, int baselen)
1356{
1357        unsigned long this_dir = 0;
1358        unsigned int sources = 0;
1359        const char *line_prefix = "";
1360        struct strbuf *msg = NULL;
1361
1362        if (opt->output_prefix) {
1363                msg = opt->output_prefix(opt, opt->output_prefix_data);
1364                line_prefix = msg->buf;
1365        }
1366
1367        while (dir->nr) {
1368                struct dirstat_file *f = dir->files;
1369                int namelen = strlen(f->name);
1370                unsigned long this;
1371                char *slash;
1372
1373                if (namelen < baselen)
1374                        break;
1375                if (memcmp(f->name, base, baselen))
1376                        break;
1377                slash = strchr(f->name + baselen, '/');
1378                if (slash) {
1379                        int newbaselen = slash + 1 - f->name;
1380                        this = gather_dirstat(opt, dir, changed, f->name, newbaselen);
1381                        sources++;
1382                } else {
1383                        this = f->changed;
1384                        dir->files++;
1385                        dir->nr--;
1386                        sources += 2;
1387                }
1388                this_dir += this;
1389        }
1390
1391        /*
1392         * We don't report dirstat's for
1393         *  - the top level
1394         *  - or cases where everything came from a single directory
1395         *    under this directory (sources == 1).
1396         */
1397        if (baselen && sources != 1) {
1398                int permille = this_dir * 1000 / changed;
1399                if (permille) {
1400                        int percent = permille / 10;
1401                        if (percent >= dir->percent) {
1402                                fprintf(opt->file, "%s%4d.%01d%% %.*s\n", line_prefix,
1403                                        percent, permille % 10, baselen, base);
1404                                if (!dir->cumulative)
1405                                        return 0;
1406                        }
1407                }
1408        }
1409        return this_dir;
1410}
1411
1412static int dirstat_compare(const void *_a, const void *_b)
1413{
1414        const struct dirstat_file *a = _a;
1415        const struct dirstat_file *b = _b;
1416        return strcmp(a->name, b->name);
1417}
1418
1419static void show_dirstat(struct diff_options *options)
1420{
1421        int i;
1422        unsigned long changed;
1423        struct dirstat_dir dir;
1424        struct diff_queue_struct *q = &diff_queued_diff;
1425
1426        dir.files = NULL;
1427        dir.alloc = 0;
1428        dir.nr = 0;
1429        dir.percent = options->dirstat_percent;
1430        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1431
1432        changed = 0;
1433        for (i = 0; i < q->nr; i++) {
1434                struct diff_filepair *p = q->queue[i];
1435                const char *name;
1436                unsigned long copied, added, damage;
1437
1438                name = p->one->path ? p->one->path : p->two->path;
1439
1440                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1441                        diff_populate_filespec(p->one, 0);
1442                        diff_populate_filespec(p->two, 0);
1443                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1444                                               &copied, &added);
1445                        diff_free_filespec_data(p->one);
1446                        diff_free_filespec_data(p->two);
1447                } else if (DIFF_FILE_VALID(p->one)) {
1448                        diff_populate_filespec(p->one, 1);
1449                        copied = added = 0;
1450                        diff_free_filespec_data(p->one);
1451                } else if (DIFF_FILE_VALID(p->two)) {
1452                        diff_populate_filespec(p->two, 1);
1453                        copied = 0;
1454                        added = p->two->size;
1455                        diff_free_filespec_data(p->two);
1456                } else
1457                        continue;
1458
1459                /*
1460                 * Original minus copied is the removed material,
1461                 * added is the new material.  They are both damages
1462                 * made to the preimage. In --dirstat-by-file mode, count
1463                 * damaged files, not damaged lines. This is done by
1464                 * counting only a single damaged line per file.
1465                 */
1466                damage = (p->one->size - copied) + added;
1467                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1468                        damage = 1;
1469
1470                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1471                dir.files[dir.nr].name = name;
1472                dir.files[dir.nr].changed = damage;
1473                changed += damage;
1474                dir.nr++;
1475        }
1476
1477        /* This can happen even with many files, if everything was renames */
1478        if (!changed)
1479                return;
1480
1481        /* Show all directories with more than x% of the changes */
1482        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1483        gather_dirstat(options, &dir, changed, "", 0);
1484}
1485
1486static void free_diffstat_info(struct diffstat_t *diffstat)
1487{
1488        int i;
1489        for (i = 0; i < diffstat->nr; i++) {
1490                struct diffstat_file *f = diffstat->files[i];
1491                if (f->name != f->print_name)
1492                        free(f->print_name);
1493                free(f->name);
1494                free(f->from_name);
1495                free(f);
1496        }
1497        free(diffstat->files);
1498}
1499
1500struct checkdiff_t {
1501        const char *filename;
1502        int lineno;
1503        int conflict_marker_size;
1504        struct diff_options *o;
1505        unsigned ws_rule;
1506        unsigned status;
1507};
1508
1509static int is_conflict_marker(const char *line, int marker_size, unsigned long len)
1510{
1511        char firstchar;
1512        int cnt;
1513
1514        if (len < marker_size + 1)
1515                return 0;
1516        firstchar = line[0];
1517        switch (firstchar) {
1518        case '=': case '>': case '<': case '|':
1519                break;
1520        default:
1521                return 0;
1522        }
1523        for (cnt = 1; cnt < marker_size; cnt++)
1524                if (line[cnt] != firstchar)
1525                        return 0;
1526        /* line[1] thru line[marker_size-1] are same as firstchar */
1527        if (len < marker_size + 1 || !isspace(line[marker_size]))
1528                return 0;
1529        return 1;
1530}
1531
1532static void checkdiff_consume(void *priv, char *line, unsigned long len)
1533{
1534        struct checkdiff_t *data = priv;
1535        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1536        int marker_size = data->conflict_marker_size;
1537        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1538        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1539        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1540        char *err;
1541        char *line_prefix = "";
1542        struct strbuf *msgbuf;
1543
1544        assert(data->o);
1545        if (data->o->output_prefix) {
1546                msgbuf = data->o->output_prefix(data->o,
1547                        data->o->output_prefix_data);
1548                line_prefix = msgbuf->buf;
1549        }
1550
1551        if (line[0] == '+') {
1552                unsigned bad;
1553                data->lineno++;
1554                if (is_conflict_marker(line + 1, marker_size, len - 1)) {
1555                        data->status |= 1;
1556                        fprintf(data->o->file,
1557                                "%s%s:%d: leftover conflict marker\n",
1558                                line_prefix, data->filename, data->lineno);
1559                }
1560                bad = ws_check(line + 1, len - 1, data->ws_rule);
1561                if (!bad)
1562                        return;
1563                data->status |= bad;
1564                err = whitespace_error_string(bad);
1565                fprintf(data->o->file, "%s%s:%d: %s.\n",
1566                        line_prefix, data->filename, data->lineno, err);
1567                free(err);
1568                emit_line(data->o, set, reset, line, 1);
1569                ws_check_emit(line + 1, len - 1, data->ws_rule,
1570                              data->o->file, set, reset, ws);
1571        } else if (line[0] == ' ') {
1572                data->lineno++;
1573        } else if (line[0] == '@') {
1574                char *plus = strchr(line, '+');
1575                if (plus)
1576                        data->lineno = strtol(plus, NULL, 10) - 1;
1577                else
1578                        die("invalid diff");
1579        }
1580}
1581
1582static unsigned char *deflate_it(char *data,
1583                                 unsigned long size,
1584                                 unsigned long *result_size)
1585{
1586        int bound;
1587        unsigned char *deflated;
1588        z_stream stream;
1589
1590        memset(&stream, 0, sizeof(stream));
1591        deflateInit(&stream, zlib_compression_level);
1592        bound = deflateBound(&stream, size);
1593        deflated = xmalloc(bound);
1594        stream.next_out = deflated;
1595        stream.avail_out = bound;
1596
1597        stream.next_in = (unsigned char *)data;
1598        stream.avail_in = size;
1599        while (deflate(&stream, Z_FINISH) == Z_OK)
1600                ; /* nothing */
1601        deflateEnd(&stream);
1602        *result_size = stream.total_out;
1603        return deflated;
1604}
1605
1606static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1607{
1608        void *cp;
1609        void *delta;
1610        void *deflated;
1611        void *data;
1612        unsigned long orig_size;
1613        unsigned long delta_size;
1614        unsigned long deflate_size;
1615        unsigned long data_size;
1616
1617        /* We could do deflated delta, or we could do just deflated two,
1618         * whichever is smaller.
1619         */
1620        delta = NULL;
1621        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1622        if (one->size && two->size) {
1623                delta = diff_delta(one->ptr, one->size,
1624                                   two->ptr, two->size,
1625                                   &delta_size, deflate_size);
1626                if (delta) {
1627                        void *to_free = delta;
1628                        orig_size = delta_size;
1629                        delta = deflate_it(delta, delta_size, &delta_size);
1630                        free(to_free);
1631                }
1632        }
1633
1634        if (delta && delta_size < deflate_size) {
1635                fprintf(file, "%sdelta %lu\n", prefix, orig_size);
1636                free(deflated);
1637                data = delta;
1638                data_size = delta_size;
1639        }
1640        else {
1641                fprintf(file, "%sliteral %lu\n", prefix, two->size);
1642                free(delta);
1643                data = deflated;
1644                data_size = deflate_size;
1645        }
1646
1647        /* emit data encoded in base85 */
1648        cp = data;
1649        while (data_size) {
1650                int bytes = (52 < data_size) ? 52 : data_size;
1651                char line[70];
1652                data_size -= bytes;
1653                if (bytes <= 26)
1654                        line[0] = bytes + 'A' - 1;
1655                else
1656                        line[0] = bytes - 26 + 'a' - 1;
1657                encode_85(line + 1, cp, bytes);
1658                cp = (char *) cp + bytes;
1659                fprintf(file, "%s", prefix);
1660                fputs(line, file);
1661                fputc('\n', file);
1662        }
1663        fprintf(file, "%s\n", prefix);
1664        free(data);
1665}
1666
1667static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two, char *prefix)
1668{
1669        fprintf(file, "%sGIT binary patch\n", prefix);
1670        emit_binary_diff_body(file, one, two, prefix);
1671        emit_binary_diff_body(file, two, one, prefix);
1672}
1673
1674static void diff_filespec_load_driver(struct diff_filespec *one)
1675{
1676        if (!one->driver)
1677                one->driver = userdiff_find_by_path(one->path);
1678        if (!one->driver)
1679                one->driver = userdiff_find_by_name("default");
1680}
1681
1682int diff_filespec_is_binary(struct diff_filespec *one)
1683{
1684        if (one->is_binary == -1) {
1685                diff_filespec_load_driver(one);
1686                if (one->driver->binary != -1)
1687                        one->is_binary = one->driver->binary;
1688                else {
1689                        if (!one->data && DIFF_FILE_VALID(one))
1690                                diff_populate_filespec(one, 0);
1691                        if (one->data)
1692                                one->is_binary = buffer_is_binary(one->data,
1693                                                one->size);
1694                        if (one->is_binary == -1)
1695                                one->is_binary = 0;
1696                }
1697        }
1698        return one->is_binary;
1699}
1700
1701static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1702{
1703        diff_filespec_load_driver(one);
1704        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1705}
1706
1707static const char *userdiff_word_regex(struct diff_filespec *one)
1708{
1709        diff_filespec_load_driver(one);
1710        return one->driver->word_regex;
1711}
1712
1713void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1714{
1715        if (!options->a_prefix)
1716                options->a_prefix = a;
1717        if (!options->b_prefix)
1718                options->b_prefix = b;
1719}
1720
1721static struct userdiff_driver *get_textconv(struct diff_filespec *one)
1722{
1723        if (!DIFF_FILE_VALID(one))
1724                return NULL;
1725        if (!S_ISREG(one->mode))
1726                return NULL;
1727        diff_filespec_load_driver(one);
1728        if (!one->driver->textconv)
1729                return NULL;
1730
1731        if (one->driver->textconv_want_cache && !one->driver->textconv_cache) {
1732                struct notes_cache *c = xmalloc(sizeof(*c));
1733                struct strbuf name = STRBUF_INIT;
1734
1735                strbuf_addf(&name, "textconv/%s", one->driver->name);
1736                notes_cache_init(c, name.buf, one->driver->textconv);
1737                one->driver->textconv_cache = c;
1738        }
1739
1740        return one->driver;
1741}
1742
1743static void builtin_diff(const char *name_a,
1744                         const char *name_b,
1745                         struct diff_filespec *one,
1746                         struct diff_filespec *two,
1747                         const char *xfrm_msg,
1748                         struct diff_options *o,
1749                         int complete_rewrite)
1750{
1751        mmfile_t mf1, mf2;
1752        const char *lbl[2];
1753        char *a_one, *b_two;
1754        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1755        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1756        const char *a_prefix, *b_prefix;
1757        struct userdiff_driver *textconv_one = NULL;
1758        struct userdiff_driver *textconv_two = NULL;
1759        struct strbuf header = STRBUF_INIT;
1760        struct strbuf *msgbuf;
1761        char *line_prefix = "";
1762
1763        if (o->output_prefix) {
1764                msgbuf = o->output_prefix(o, o->output_prefix_data);
1765                line_prefix = msgbuf->buf;
1766        }
1767
1768        if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
1769                        (!one->mode || S_ISGITLINK(one->mode)) &&
1770                        (!two->mode || S_ISGITLINK(two->mode))) {
1771                const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
1772                const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
1773                show_submodule_summary(o->file, one ? one->path : two->path,
1774                                one->sha1, two->sha1, two->dirty_submodule,
1775                                del, add, reset);
1776                return;
1777        }
1778
1779        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1780                textconv_one = get_textconv(one);
1781                textconv_two = get_textconv(two);
1782        }
1783
1784        diff_set_mnemonic_prefix(o, "a/", "b/");
1785        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1786                a_prefix = o->b_prefix;
1787                b_prefix = o->a_prefix;
1788        } else {
1789                a_prefix = o->a_prefix;
1790                b_prefix = o->b_prefix;
1791        }
1792
1793        /* Never use a non-valid filename anywhere if at all possible */
1794        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1795        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1796
1797        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1798        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1799        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1800        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1801        strbuf_addf(&header, "%s%sdiff --git %s %s%s\n", line_prefix, set, a_one, b_two, reset);
1802        if (lbl[0][0] == '/') {
1803                /* /dev/null */
1804                strbuf_addf(&header, "%s%snew file mode %06o%s\n", line_prefix, set, two->mode, reset);
1805                if (xfrm_msg && xfrm_msg[0])
1806                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1807        }
1808        else if (lbl[1][0] == '/') {
1809                strbuf_addf(&header, "%s%sdeleted file mode %06o%s\n", line_prefix, set, one->mode, reset);
1810                if (xfrm_msg && xfrm_msg[0])
1811                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1812        }
1813        else {
1814                if (one->mode != two->mode) {
1815                        strbuf_addf(&header, "%s%sold mode %06o%s\n", line_prefix, set, one->mode, reset);
1816                        strbuf_addf(&header, "%s%snew mode %06o%s\n", line_prefix, set, two->mode, reset);
1817                }
1818                if (xfrm_msg && xfrm_msg[0])
1819                        strbuf_addf(&header, "%s%s%s\n", set, xfrm_msg, reset);
1820
1821                /*
1822                 * we do not run diff between different kind
1823                 * of objects.
1824                 */
1825                if ((one->mode ^ two->mode) & S_IFMT)
1826                        goto free_ab_and_return;
1827                if (complete_rewrite &&
1828                    (textconv_one || !diff_filespec_is_binary(one)) &&
1829                    (textconv_two || !diff_filespec_is_binary(two))) {
1830                        fprintf(o->file, "%s", header.buf);
1831                        strbuf_reset(&header);
1832                        emit_rewrite_diff(name_a, name_b, one, two,
1833                                                textconv_one, textconv_two, o);
1834                        o->found_changes = 1;
1835                        goto free_ab_and_return;
1836                }
1837        }
1838
1839        if (!DIFF_OPT_TST(o, TEXT) &&
1840            ( (!textconv_one && diff_filespec_is_binary(one)) ||
1841              (!textconv_two && diff_filespec_is_binary(two)) )) {
1842                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1843                        die("unable to read files to diff");
1844                /* Quite common confusing case */
1845                if (mf1.size == mf2.size &&
1846                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1847                        goto free_ab_and_return;
1848                fprintf(o->file, "%s", header.buf);
1849                strbuf_reset(&header);
1850                if (DIFF_OPT_TST(o, BINARY))
1851                        emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
1852                else
1853                        fprintf(o->file, "%sBinary files %s and %s differ\n",
1854                                line_prefix, lbl[0], lbl[1]);
1855                o->found_changes = 1;
1856        }
1857        else {
1858                /* Crazy xdl interfaces.. */
1859                const char *diffopts = getenv("GIT_DIFF_OPTS");
1860                xpparam_t xpp;
1861                xdemitconf_t xecfg;
1862                struct emit_callback ecbdata;
1863                const struct userdiff_funcname *pe;
1864
1865                if (!DIFF_XDL_TST(o, WHITESPACE_FLAGS)) {
1866                        fprintf(o->file, "%s", header.buf);
1867                        strbuf_reset(&header);
1868                }
1869
1870                mf1.size = fill_textconv(textconv_one, one, &mf1.ptr);
1871                mf2.size = fill_textconv(textconv_two, two, &mf2.ptr);
1872
1873                pe = diff_funcname_pattern(one);
1874                if (!pe)
1875                        pe = diff_funcname_pattern(two);
1876
1877                memset(&xpp, 0, sizeof(xpp));
1878                memset(&xecfg, 0, sizeof(xecfg));
1879                memset(&ecbdata, 0, sizeof(ecbdata));
1880                ecbdata.label_path = lbl;
1881                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1882                ecbdata.found_changesp = &o->found_changes;
1883                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1884                if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
1885                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
1886                ecbdata.opt = o;
1887                ecbdata.header = header.len ? &header : NULL;
1888                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1889                xecfg.ctxlen = o->context;
1890                xecfg.interhunkctxlen = o->interhunkcontext;
1891                xecfg.flags = XDL_EMIT_FUNCNAMES;
1892                if (pe)
1893                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1894                if (!diffopts)
1895                        ;
1896                else if (!prefixcmp(diffopts, "--unified="))
1897                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1898                else if (!prefixcmp(diffopts, "-u"))
1899                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1900                if (o->word_diff) {
1901                        int i;
1902
1903                        ecbdata.diff_words =
1904                                xcalloc(1, sizeof(struct diff_words_data));
1905                        ecbdata.diff_words->file = o->file;
1906                        ecbdata.diff_words->type = o->word_diff;
1907                        if (!o->word_regex)
1908                                o->word_regex = userdiff_word_regex(one);
1909                        if (!o->word_regex)
1910                                o->word_regex = userdiff_word_regex(two);
1911                        if (!o->word_regex)
1912                                o->word_regex = diff_word_regex_cfg;
1913                        if (o->word_regex) {
1914                                ecbdata.diff_words->word_regex = (regex_t *)
1915                                        xmalloc(sizeof(regex_t));
1916                                if (regcomp(ecbdata.diff_words->word_regex,
1917                                                o->word_regex,
1918                                                REG_EXTENDED | REG_NEWLINE))
1919                                        die ("Invalid regular expression: %s",
1920                                                        o->word_regex);
1921                        }
1922                        for (i = 0; i < ARRAY_SIZE(diff_words_styles); i++) {
1923                                if (o->word_diff == diff_words_styles[i].type) {
1924                                        ecbdata.diff_words->style =
1925                                                &diff_words_styles[i];
1926                                        break;
1927                                }
1928                        }
1929                        if (DIFF_OPT_TST(o, COLOR_DIFF)) {
1930                                struct diff_words_style *st = ecbdata.diff_words->style;
1931                                st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
1932                                st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
1933                                st->ctx.color = diff_get_color_opt(o, DIFF_PLAIN);
1934                        }
1935                }
1936                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1937                              &xpp, &xecfg);
1938                if (o->word_diff)
1939                        free_diff_words_data(&ecbdata);
1940                if (textconv_one)
1941                        free(mf1.ptr);
1942                if (textconv_two)
1943                        free(mf2.ptr);
1944                xdiff_clear_find_func(&xecfg);
1945        }
1946
1947 free_ab_and_return:
1948        strbuf_release(&header);
1949        diff_free_filespec_data(one);
1950        diff_free_filespec_data(two);
1951        free(a_one);
1952        free(b_two);
1953        return;
1954}
1955
1956static void builtin_diffstat(const char *name_a, const char *name_b,
1957                             struct diff_filespec *one,
1958                             struct diff_filespec *two,
1959                             struct diffstat_t *diffstat,
1960                             struct diff_options *o,
1961                             int complete_rewrite)
1962{
1963        mmfile_t mf1, mf2;
1964        struct diffstat_file *data;
1965
1966        data = diffstat_add(diffstat, name_a, name_b);
1967
1968        if (!one || !two) {
1969                data->is_unmerged = 1;
1970                return;
1971        }
1972        if (complete_rewrite) {
1973                diff_populate_filespec(one, 0);
1974                diff_populate_filespec(two, 0);
1975                data->deleted = count_lines(one->data, one->size);
1976                data->added = count_lines(two->data, two->size);
1977                goto free_and_return;
1978        }
1979        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1980                die("unable to read files to diff");
1981
1982        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1983                data->is_binary = 1;
1984                data->added = mf2.size;
1985                data->deleted = mf1.size;
1986        } else {
1987                /* Crazy xdl interfaces.. */
1988                xpparam_t xpp;
1989                xdemitconf_t xecfg;
1990
1991                memset(&xpp, 0, sizeof(xpp));
1992                memset(&xecfg, 0, sizeof(xecfg));
1993                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1994                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1995                              &xpp, &xecfg);
1996        }
1997
1998 free_and_return:
1999        diff_free_filespec_data(one);
2000        diff_free_filespec_data(two);
2001}
2002
2003static void builtin_checkdiff(const char *name_a, const char *name_b,
2004                              const char *attr_path,
2005                              struct diff_filespec *one,
2006                              struct diff_filespec *two,
2007                              struct diff_options *o)
2008{
2009        mmfile_t mf1, mf2;
2010        struct checkdiff_t data;
2011
2012        if (!two)
2013                return;
2014
2015        memset(&data, 0, sizeof(data));
2016        data.filename = name_b ? name_b : name_a;
2017        data.lineno = 0;
2018        data.o = o;
2019        data.ws_rule = whitespace_rule(attr_path);
2020        data.conflict_marker_size = ll_merge_marker_size(attr_path);
2021
2022        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
2023                die("unable to read files to diff");
2024
2025        /*
2026         * All the other codepaths check both sides, but not checking
2027         * the "old" side here is deliberate.  We are checking the newly
2028         * introduced changes, and as long as the "new" side is text, we
2029         * can and should check what it introduces.
2030         */
2031        if (diff_filespec_is_binary(two))
2032                goto free_and_return;
2033        else {
2034                /* Crazy xdl interfaces.. */
2035                xpparam_t xpp;
2036                xdemitconf_t xecfg;
2037
2038                memset(&xpp, 0, sizeof(xpp));
2039                memset(&xecfg, 0, sizeof(xecfg));
2040                xecfg.ctxlen = 1; /* at least one context line */
2041                xpp.flags = XDF_NEED_MINIMAL;
2042                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
2043                              &xpp, &xecfg);
2044
2045                if (data.ws_rule & WS_BLANK_AT_EOF) {
2046                        struct emit_callback ecbdata;
2047                        int blank_at_eof;
2048
2049                        ecbdata.ws_rule = data.ws_rule;
2050                        check_blank_at_eof(&mf1, &mf2, &ecbdata);
2051                        blank_at_eof = ecbdata.blank_at_eof_in_preimage;
2052
2053                        if (blank_at_eof) {
2054                                static char *err;
2055                                if (!err)
2056                                        err = whitespace_error_string(WS_BLANK_AT_EOF);
2057                                fprintf(o->file, "%s:%d: %s.\n",
2058                                        data.filename, blank_at_eof, err);
2059                                data.status = 1; /* report errors */
2060                        }
2061                }
2062        }
2063 free_and_return:
2064        diff_free_filespec_data(one);
2065        diff_free_filespec_data(two);
2066        if (data.status)
2067                DIFF_OPT_SET(o, CHECK_FAILED);
2068}
2069
2070struct diff_filespec *alloc_filespec(const char *path)
2071{
2072        int namelen = strlen(path);
2073        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
2074
2075        memset(spec, 0, sizeof(*spec));
2076        spec->path = (char *)(spec + 1);
2077        memcpy(spec->path, path, namelen+1);
2078        spec->count = 1;
2079        spec->is_binary = -1;
2080        return spec;
2081}
2082
2083void free_filespec(struct diff_filespec *spec)
2084{
2085        if (!--spec->count) {
2086                diff_free_filespec_data(spec);
2087                free(spec);
2088        }
2089}
2090
2091void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
2092                   unsigned short mode)
2093{
2094        if (mode) {
2095                spec->mode = canon_mode(mode);
2096                hashcpy(spec->sha1, sha1);
2097                spec->sha1_valid = !is_null_sha1(sha1);
2098        }
2099}
2100
2101/*
2102 * Given a name and sha1 pair, if the index tells us the file in
2103 * the work tree has that object contents, return true, so that
2104 * prepare_temp_file() does not have to inflate and extract.
2105 */
2106static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
2107{
2108        struct cache_entry *ce;
2109        struct stat st;
2110        int pos, len;
2111
2112        /*
2113         * We do not read the cache ourselves here, because the
2114         * benchmark with my previous version that always reads cache
2115         * shows that it makes things worse for diff-tree comparing
2116         * two linux-2.6 kernel trees in an already checked out work
2117         * tree.  This is because most diff-tree comparisons deal with
2118         * only a small number of files, while reading the cache is
2119         * expensive for a large project, and its cost outweighs the
2120         * savings we get by not inflating the object to a temporary
2121         * file.  Practically, this code only helps when we are used
2122         * by diff-cache --cached, which does read the cache before
2123         * calling us.
2124         */
2125        if (!active_cache)
2126                return 0;
2127
2128        /* We want to avoid the working directory if our caller
2129         * doesn't need the data in a normal file, this system
2130         * is rather slow with its stat/open/mmap/close syscalls,
2131         * and the object is contained in a pack file.  The pack
2132         * is probably already open and will be faster to obtain
2133         * the data through than the working directory.  Loose
2134         * objects however would tend to be slower as they need
2135         * to be individually opened and inflated.
2136         */
2137        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
2138                return 0;
2139
2140        len = strlen(name);
2141        pos = cache_name_pos(name, len);
2142        if (pos < 0)
2143                return 0;
2144        ce = active_cache[pos];
2145
2146        /*
2147         * This is not the sha1 we are looking for, or
2148         * unreusable because it is not a regular file.
2149         */
2150        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
2151                return 0;
2152
2153        /*
2154         * If ce is marked as "assume unchanged", there is no
2155         * guarantee that work tree matches what we are looking for.
2156         */
2157        if ((ce->ce_flags & CE_VALID) || ce_skip_worktree(ce))
2158                return 0;
2159
2160        /*
2161         * If ce matches the file in the work tree, we can reuse it.
2162         */
2163        if (ce_uptodate(ce) ||
2164            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
2165                return 1;
2166
2167        return 0;
2168}
2169
2170static int populate_from_stdin(struct diff_filespec *s)
2171{
2172        struct strbuf buf = STRBUF_INIT;
2173        size_t size = 0;
2174
2175        if (strbuf_read(&buf, 0, 0) < 0)
2176                return error("error while reading from stdin %s",
2177                                     strerror(errno));
2178
2179        s->should_munmap = 0;
2180        s->data = strbuf_detach(&buf, &size);
2181        s->size = size;
2182        s->should_free = 1;
2183        return 0;
2184}
2185
2186static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
2187{
2188        int len;
2189        char *data = xmalloc(100), *dirty = "";
2190
2191        /* Are we looking at the work tree? */
2192        if (s->dirty_submodule)
2193                dirty = "-dirty";
2194
2195        len = snprintf(data, 100,
2196                       "Subproject commit %s%s\n", sha1_to_hex(s->sha1), dirty);
2197        s->data = data;
2198        s->size = len;
2199        s->should_free = 1;
2200        if (size_only) {
2201                s->data = NULL;
2202                free(data);
2203        }
2204        return 0;
2205}
2206
2207/*
2208 * While doing rename detection and pickaxe operation, we may need to
2209 * grab the data for the blob (or file) for our own in-core comparison.
2210 * diff_filespec has data and size fields for this purpose.
2211 */
2212int diff_populate_filespec(struct diff_filespec *s, int size_only)
2213{
2214        int err = 0;
2215        if (!DIFF_FILE_VALID(s))
2216                die("internal error: asking to populate invalid file.");
2217        if (S_ISDIR(s->mode))
2218                return -1;
2219
2220        if (s->data)
2221                return 0;
2222
2223        if (size_only && 0 < s->size)
2224                return 0;
2225
2226        if (S_ISGITLINK(s->mode))
2227                return diff_populate_gitlink(s, size_only);
2228
2229        if (!s->sha1_valid ||
2230            reuse_worktree_file(s->path, s->sha1, 0)) {
2231                struct strbuf buf = STRBUF_INIT;
2232                struct stat st;
2233                int fd;
2234
2235                if (!strcmp(s->path, "-"))
2236                        return populate_from_stdin(s);
2237
2238                if (lstat(s->path, &st) < 0) {
2239                        if (errno == ENOENT) {
2240                        err_empty:
2241                                err = -1;
2242                        empty:
2243                                s->data = (char *)"";
2244                                s->size = 0;
2245                                return err;
2246                        }
2247                }
2248                s->size = xsize_t(st.st_size);
2249                if (!s->size)
2250                        goto empty;
2251                if (S_ISLNK(st.st_mode)) {
2252                        struct strbuf sb = STRBUF_INIT;
2253
2254                        if (strbuf_readlink(&sb, s->path, s->size))
2255                                goto err_empty;
2256                        s->size = sb.len;
2257                        s->data = strbuf_detach(&sb, NULL);
2258                        s->should_free = 1;
2259                        return 0;
2260                }
2261                if (size_only)
2262                        return 0;
2263                fd = open(s->path, O_RDONLY);
2264                if (fd < 0)
2265                        goto err_empty;
2266                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
2267                close(fd);
2268                s->should_munmap = 1;
2269
2270                /*
2271                 * Convert from working tree format to canonical git format
2272                 */
2273                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
2274                        size_t size = 0;
2275                        munmap(s->data, s->size);
2276                        s->should_munmap = 0;
2277                        s->data = strbuf_detach(&buf, &size);
2278                        s->size = size;
2279                        s->should_free = 1;
2280                }
2281        }
2282        else {
2283                enum object_type type;
2284                if (size_only)
2285                        type = sha1_object_info(s->sha1, &s->size);
2286                else {
2287                        s->data = read_sha1_file(s->sha1, &type, &s->size);
2288                        s->should_free = 1;
2289                }
2290        }
2291        return 0;
2292}
2293
2294void diff_free_filespec_blob(struct diff_filespec *s)
2295{
2296        if (s->should_free)
2297                free(s->data);
2298        else if (s->should_munmap)
2299                munmap(s->data, s->size);
2300
2301        if (s->should_free || s->should_munmap) {
2302                s->should_free = s->should_munmap = 0;
2303                s->data = NULL;
2304        }
2305}
2306
2307void diff_free_filespec_data(struct diff_filespec *s)
2308{
2309        diff_free_filespec_blob(s);
2310        free(s->cnt_data);
2311        s->cnt_data = NULL;
2312}
2313
2314static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
2315                           void *blob,
2316                           unsigned long size,
2317                           const unsigned char *sha1,
2318                           int mode)
2319{
2320        int fd;
2321        struct strbuf buf = STRBUF_INIT;
2322        struct strbuf template = STRBUF_INIT;
2323        char *path_dup = xstrdup(path);
2324        const char *base = basename(path_dup);
2325
2326        /* Generate "XXXXXX_basename.ext" */
2327        strbuf_addstr(&template, "XXXXXX_");
2328        strbuf_addstr(&template, base);
2329
2330        fd = git_mkstemps(temp->tmp_path, PATH_MAX, template.buf,
2331                        strlen(base) + 1);
2332        if (fd < 0)
2333                die_errno("unable to create temp-file");
2334        if (convert_to_working_tree(path,
2335                        (const char *)blob, (size_t)size, &buf)) {
2336                blob = buf.buf;
2337                size = buf.len;
2338        }
2339        if (write_in_full(fd, blob, size) != size)
2340                die_errno("unable to write temp-file");
2341        close(fd);
2342        temp->name = temp->tmp_path;
2343        strcpy(temp->hex, sha1_to_hex(sha1));
2344        temp->hex[40] = 0;
2345        sprintf(temp->mode, "%06o", mode);
2346        strbuf_release(&buf);
2347        strbuf_release(&template);
2348        free(path_dup);
2349}
2350
2351static struct diff_tempfile *prepare_temp_file(const char *name,
2352                struct diff_filespec *one)
2353{
2354        struct diff_tempfile *temp = claim_diff_tempfile();
2355
2356        if (!DIFF_FILE_VALID(one)) {
2357        not_a_valid_file:
2358                /* A '-' entry produces this for file-2, and
2359                 * a '+' entry produces this for file-1.
2360                 */
2361                temp->name = "/dev/null";
2362                strcpy(temp->hex, ".");
2363                strcpy(temp->mode, ".");
2364                return temp;
2365        }
2366
2367        if (!remove_tempfile_installed) {
2368                atexit(remove_tempfile);
2369                sigchain_push_common(remove_tempfile_on_signal);
2370                remove_tempfile_installed = 1;
2371        }
2372
2373        if (!one->sha1_valid ||
2374            reuse_worktree_file(name, one->sha1, 1)) {
2375                struct stat st;
2376                if (lstat(name, &st) < 0) {
2377                        if (errno == ENOENT)
2378                                goto not_a_valid_file;
2379                        die_errno("stat(%s)", name);
2380                }
2381                if (S_ISLNK(st.st_mode)) {
2382                        struct strbuf sb = STRBUF_INIT;
2383                        if (strbuf_readlink(&sb, name, st.st_size) < 0)
2384                                die_errno("readlink(%s)", name);
2385                        prep_temp_blob(name, temp, sb.buf, sb.len,
2386                                       (one->sha1_valid ?
2387                                        one->sha1 : null_sha1),
2388                                       (one->sha1_valid ?
2389                                        one->mode : S_IFLNK));
2390                        strbuf_release(&sb);
2391                }
2392                else {
2393                        /* we can borrow from the file in the work tree */
2394                        temp->name = name;
2395                        if (!one->sha1_valid)
2396                                strcpy(temp->hex, sha1_to_hex(null_sha1));
2397                        else
2398                                strcpy(temp->hex, sha1_to_hex(one->sha1));
2399                        /* Even though we may sometimes borrow the
2400                         * contents from the work tree, we always want
2401                         * one->mode.  mode is trustworthy even when
2402                         * !(one->sha1_valid), as long as
2403                         * DIFF_FILE_VALID(one).
2404                         */
2405                        sprintf(temp->mode, "%06o", one->mode);
2406                }
2407                return temp;
2408        }
2409        else {
2410                if (diff_populate_filespec(one, 0))
2411                        die("cannot read data blob for %s", one->path);
2412                prep_temp_blob(name, temp, one->data, one->size,
2413                               one->sha1, one->mode);
2414        }
2415        return temp;
2416}
2417
2418/* An external diff command takes:
2419 *
2420 * diff-cmd name infile1 infile1-sha1 infile1-mode \
2421 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
2422 *
2423 */
2424static void run_external_diff(const char *pgm,
2425                              const char *name,
2426                              const char *other,
2427                              struct diff_filespec *one,
2428                              struct diff_filespec *two,
2429                              const char *xfrm_msg,
2430                              int complete_rewrite)
2431{
2432        const char *spawn_arg[10];
2433        int retval;
2434        const char **arg = &spawn_arg[0];
2435
2436        if (one && two) {
2437                struct diff_tempfile *temp_one, *temp_two;
2438                const char *othername = (other ? other : name);
2439                temp_one = prepare_temp_file(name, one);
2440                temp_two = prepare_temp_file(othername, two);
2441                *arg++ = pgm;
2442                *arg++ = name;
2443                *arg++ = temp_one->name;
2444                *arg++ = temp_one->hex;
2445                *arg++ = temp_one->mode;
2446                *arg++ = temp_two->name;
2447                *arg++ = temp_two->hex;
2448                *arg++ = temp_two->mode;
2449                if (other) {
2450                        *arg++ = other;
2451                        *arg++ = xfrm_msg;
2452                }
2453        } else {
2454                *arg++ = pgm;
2455                *arg++ = name;
2456        }
2457        *arg = NULL;
2458        fflush(NULL);
2459        retval = run_command_v_opt(spawn_arg, RUN_USING_SHELL);
2460        remove_tempfile();
2461        if (retval) {
2462                fprintf(stderr, "external diff died, stopping at %s.\n", name);
2463                exit(1);
2464        }
2465}
2466
2467static int similarity_index(struct diff_filepair *p)
2468{
2469        return p->score * 100 / MAX_SCORE;
2470}
2471
2472static void fill_metainfo(struct strbuf *msg,
2473                          const char *name,
2474                          const char *other,
2475                          struct diff_filespec *one,
2476                          struct diff_filespec *two,
2477                          struct diff_options *o,
2478                          struct diff_filepair *p)
2479{
2480        struct strbuf *msgbuf;
2481        char *line_prefix = "";
2482
2483        if (o->output_prefix) {
2484                msgbuf = o->output_prefix(o, o->output_prefix_data);
2485                line_prefix = msgbuf->buf;
2486        }
2487
2488        strbuf_init(msg, PATH_MAX * 2 + 300);
2489        switch (p->status) {
2490        case DIFF_STATUS_COPIED:
2491                strbuf_addf(msg, "%ssimilarity index %d%%", line_prefix, similarity_index(p));
2492                strbuf_addf(msg, "\n%scopy from ", line_prefix);
2493                quote_c_style(name, msg, NULL, 0);
2494                strbuf_addf(msg, "\n%scopy to ", line_prefix);
2495                quote_c_style(other, msg, NULL, 0);
2496                strbuf_addch(msg, '\n');
2497                break;
2498        case DIFF_STATUS_RENAMED:
2499                strbuf_addf(msg, "%ssimilarity index %d%%", line_prefix, similarity_index(p));
2500                strbuf_addf(msg, "\n%srename from ", line_prefix);
2501                quote_c_style(name, msg, NULL, 0);
2502                strbuf_addf(msg, "\n%srename to ", line_prefix);
2503                quote_c_style(other, msg, NULL, 0);
2504                strbuf_addch(msg, '\n');
2505                break;
2506        case DIFF_STATUS_MODIFIED:
2507                if (p->score) {
2508                        strbuf_addf(msg, "%sdissimilarity index %d%%\n",
2509                                    line_prefix, similarity_index(p));
2510                        break;
2511                }
2512                /* fallthru */
2513        default:
2514                /* nothing */
2515                ;
2516        }
2517        if (one && two && hashcmp(one->sha1, two->sha1)) {
2518                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2519
2520                if (DIFF_OPT_TST(o, BINARY)) {
2521                        mmfile_t mf;
2522                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2523                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2524                                abbrev = 40;
2525                }
2526                strbuf_addf(msg, "%sindex %.*s..%.*s",
2527                            line_prefix, abbrev, sha1_to_hex(one->sha1),
2528                            abbrev, sha1_to_hex(two->sha1));
2529                if (one->mode == two->mode)
2530                        strbuf_addf(msg, " %06o", one->mode);
2531                strbuf_addch(msg, '\n');
2532        }
2533        if (msg->len)
2534                strbuf_setlen(msg, msg->len - 1);
2535}
2536
2537static void run_diff_cmd(const char *pgm,
2538                         const char *name,
2539                         const char *other,
2540                         const char *attr_path,
2541                         struct diff_filespec *one,
2542                         struct diff_filespec *two,
2543                         struct strbuf *msg,
2544                         struct diff_options *o,
2545                         struct diff_filepair *p)
2546{
2547        const char *xfrm_msg = NULL;
2548        int complete_rewrite = (p->status == DIFF_STATUS_MODIFIED) && p->score;
2549
2550        if (msg) {
2551                fill_metainfo(msg, name, other, one, two, o, p);
2552                xfrm_msg = msg->len ? msg->buf : NULL;
2553        }
2554
2555        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2556                pgm = NULL;
2557        else {
2558                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2559                if (drv && drv->external)
2560                        pgm = drv->external;
2561        }
2562
2563        if (pgm) {
2564                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2565                                  complete_rewrite);
2566                return;
2567        }
2568        if (one && two)
2569                builtin_diff(name, other ? other : name,
2570                             one, two, xfrm_msg, o, complete_rewrite);
2571        else
2572                fprintf(o->file, "* Unmerged path %s\n", name);
2573}
2574
2575static void diff_fill_sha1_info(struct diff_filespec *one)
2576{
2577        if (DIFF_FILE_VALID(one)) {
2578                if (!one->sha1_valid) {
2579                        struct stat st;
2580                        if (!strcmp(one->path, "-")) {
2581                                hashcpy(one->sha1, null_sha1);
2582                                return;
2583                        }
2584                        if (lstat(one->path, &st) < 0)
2585                                die_errno("stat '%s'", one->path);
2586                        if (index_path(one->sha1, one->path, &st, 0))
2587                                die("cannot hash %s", one->path);
2588                }
2589        }
2590        else
2591                hashclr(one->sha1);
2592}
2593
2594static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2595{
2596        /* Strip the prefix but do not molest /dev/null and absolute paths */
2597        if (*namep && **namep != '/')
2598                *namep += prefix_length;
2599        if (*otherp && **otherp != '/')
2600                *otherp += prefix_length;
2601}
2602
2603static void run_diff(struct diff_filepair *p, struct diff_options *o)
2604{
2605        const char *pgm = external_diff();
2606        struct strbuf msg;
2607        struct diff_filespec *one = p->one;
2608        struct diff_filespec *two = p->two;
2609        const char *name;
2610        const char *other;
2611        const char *attr_path;
2612
2613        name  = p->one->path;
2614        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2615        attr_path = name;
2616        if (o->prefix_length)
2617                strip_prefix(o->prefix_length, &name, &other);
2618
2619        if (DIFF_PAIR_UNMERGED(p)) {
2620                run_diff_cmd(pgm, name, NULL, attr_path,
2621                             NULL, NULL, NULL, o, p);
2622                return;
2623        }
2624
2625        diff_fill_sha1_info(one);
2626        diff_fill_sha1_info(two);
2627
2628        if (!pgm &&
2629            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2630            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2631                /*
2632                 * a filepair that changes between file and symlink
2633                 * needs to be split into deletion and creation.
2634                 */
2635                struct diff_filespec *null = alloc_filespec(two->path);
2636                run_diff_cmd(NULL, name, other, attr_path,
2637                             one, null, &msg, o, p);
2638                free(null);
2639                strbuf_release(&msg);
2640
2641                null = alloc_filespec(one->path);
2642                run_diff_cmd(NULL, name, other, attr_path,
2643                             null, two, &msg, o, p);
2644                free(null);
2645        }
2646        else
2647                run_diff_cmd(pgm, name, other, attr_path,
2648                             one, two, &msg, o, p);
2649
2650        strbuf_release(&msg);
2651}
2652
2653static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2654                         struct diffstat_t *diffstat)
2655{
2656        const char *name;
2657        const char *other;
2658        int complete_rewrite = 0;
2659
2660        if (DIFF_PAIR_UNMERGED(p)) {
2661                /* unmerged */
2662                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2663                return;
2664        }
2665
2666        name = p->one->path;
2667        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2668
2669        if (o->prefix_length)
2670                strip_prefix(o->prefix_length, &name, &other);
2671
2672        diff_fill_sha1_info(p->one);
2673        diff_fill_sha1_info(p->two);
2674
2675        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2676                complete_rewrite = 1;
2677        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2678}
2679
2680static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2681{
2682        const char *name;
2683        const char *other;
2684        const char *attr_path;
2685
2686        if (DIFF_PAIR_UNMERGED(p)) {
2687                /* unmerged */
2688                return;
2689        }
2690
2691        name = p->one->path;
2692        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2693        attr_path = other ? other : name;
2694
2695        if (o->prefix_length)
2696                strip_prefix(o->prefix_length, &name, &other);
2697
2698        diff_fill_sha1_info(p->one);
2699        diff_fill_sha1_info(p->two);
2700
2701        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2702}
2703
2704void diff_setup(struct diff_options *options)
2705{
2706        memset(options, 0, sizeof(*options));
2707        memset(&diff_queued_diff, 0, sizeof(diff_queued_diff));
2708
2709        options->file = stdout;
2710
2711        options->line_termination = '\n';
2712        options->break_opt = -1;
2713        options->rename_limit = -1;
2714        options->dirstat_percent = 3;
2715        options->context = 3;
2716
2717        options->change = diff_change;
2718        options->add_remove = diff_addremove;
2719        if (diff_use_color_default > 0)
2720                DIFF_OPT_SET(options, COLOR_DIFF);
2721        options->detect_rename = diff_detect_rename_default;
2722
2723        if (!diff_mnemonic_prefix) {
2724                options->a_prefix = "a/";
2725                options->b_prefix = "b/";
2726        }
2727}
2728
2729int diff_setup_done(struct diff_options *options)
2730{
2731        int count = 0;
2732
2733        if (options->output_format & DIFF_FORMAT_NAME)
2734                count++;
2735        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2736                count++;
2737        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2738                count++;
2739        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2740                count++;
2741        if (count > 1)
2742                die("--name-only, --name-status, --check and -s are mutually exclusive");
2743
2744        /*
2745         * Most of the time we can say "there are changes"
2746         * only by checking if there are changed paths, but
2747         * --ignore-whitespace* options force us to look
2748         * inside contents.
2749         */
2750
2751        if (DIFF_XDL_TST(options, IGNORE_WHITESPACE) ||
2752            DIFF_XDL_TST(options, IGNORE_WHITESPACE_CHANGE) ||
2753            DIFF_XDL_TST(options, IGNORE_WHITESPACE_AT_EOL))
2754                DIFF_OPT_SET(options, DIFF_FROM_CONTENTS);
2755        else
2756                DIFF_OPT_CLR(options, DIFF_FROM_CONTENTS);
2757
2758        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2759                options->detect_rename = DIFF_DETECT_COPY;
2760
2761        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2762                options->prefix = NULL;
2763        if (options->prefix)
2764                options->prefix_length = strlen(options->prefix);
2765        else
2766                options->prefix_length = 0;
2767
2768        if (options->output_format & (DIFF_FORMAT_NAME |
2769                                      DIFF_FORMAT_NAME_STATUS |
2770                                      DIFF_FORMAT_CHECKDIFF |
2771                                      DIFF_FORMAT_NO_OUTPUT))
2772                options->output_format &= ~(DIFF_FORMAT_RAW |
2773                                            DIFF_FORMAT_NUMSTAT |
2774                                            DIFF_FORMAT_DIFFSTAT |
2775                                            DIFF_FORMAT_SHORTSTAT |
2776                                            DIFF_FORMAT_DIRSTAT |
2777                                            DIFF_FORMAT_SUMMARY |
2778                                            DIFF_FORMAT_PATCH);
2779
2780        /*
2781         * These cases always need recursive; we do not drop caller-supplied
2782         * recursive bits for other formats here.
2783         */
2784        if (options->output_format & (DIFF_FORMAT_PATCH |
2785                                      DIFF_FORMAT_NUMSTAT |
2786                                      DIFF_FORMAT_DIFFSTAT |
2787                                      DIFF_FORMAT_SHORTSTAT |
2788                                      DIFF_FORMAT_DIRSTAT |
2789                                      DIFF_FORMAT_SUMMARY |
2790                                      DIFF_FORMAT_CHECKDIFF))
2791                DIFF_OPT_SET(options, RECURSIVE);
2792        /*
2793         * Also pickaxe would not work very well if you do not say recursive
2794         */
2795        if (options->pickaxe)
2796                DIFF_OPT_SET(options, RECURSIVE);
2797        /*
2798         * When patches are generated, submodules diffed against the work tree
2799         * must be checked for dirtiness too so it can be shown in the output
2800         */
2801        if (options->output_format & DIFF_FORMAT_PATCH)
2802                DIFF_OPT_SET(options, DIRTY_SUBMODULES);
2803
2804        if (options->detect_rename && options->rename_limit < 0)
2805                options->rename_limit = diff_rename_limit_default;
2806        if (options->setup & DIFF_SETUP_USE_CACHE) {
2807                if (!active_cache)
2808                        /* read-cache does not die even when it fails
2809                         * so it is safe for us to do this here.  Also
2810                         * it does not smudge active_cache or active_nr
2811                         * when it fails, so we do not have to worry about
2812                         * cleaning it up ourselves either.
2813                         */
2814                        read_cache();
2815        }
2816        if (options->abbrev <= 0 || 40 < options->abbrev)
2817                options->abbrev = 40; /* full */
2818
2819        /*
2820         * It does not make sense to show the first hit we happened
2821         * to have found.  It does not make sense not to return with
2822         * exit code in such a case either.
2823         */
2824        if (DIFF_OPT_TST(options, QUICK)) {
2825                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2826                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2827        }
2828
2829        return 0;
2830}
2831
2832static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2833{
2834        char c, *eq;
2835        int len;
2836
2837        if (*arg != '-')
2838                return 0;
2839        c = *++arg;
2840        if (!c)
2841                return 0;
2842        if (c == arg_short) {
2843                c = *++arg;
2844                if (!c)
2845                        return 1;
2846                if (val && isdigit(c)) {
2847                        char *end;
2848                        int n = strtoul(arg, &end, 10);
2849                        if (*end)
2850                                return 0;
2851                        *val = n;
2852                        return 1;
2853                }
2854                return 0;
2855        }
2856        if (c != '-')
2857                return 0;
2858        arg++;
2859        eq = strchr(arg, '=');
2860        if (eq)
2861                len = eq - arg;
2862        else
2863                len = strlen(arg);
2864        if (!len || strncmp(arg, arg_long, len))
2865                return 0;
2866        if (eq) {
2867                int n;
2868                char *end;
2869                if (!isdigit(*++eq))
2870                        return 0;
2871                n = strtoul(eq, &end, 10);
2872                if (*end)
2873                        return 0;
2874                *val = n;
2875        }
2876        return 1;
2877}
2878
2879static int diff_scoreopt_parse(const char *opt);
2880
2881int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2882{
2883        const char *arg = av[0];
2884
2885        /* Output format options */
2886        if (!strcmp(arg, "-p") || !strcmp(arg, "-u") || !strcmp(arg, "--patch"))
2887                options->output_format |= DIFF_FORMAT_PATCH;
2888        else if (opt_arg(arg, 'U', "unified", &options->context))
2889                options->output_format |= DIFF_FORMAT_PATCH;
2890        else if (!strcmp(arg, "--raw"))
2891                options->output_format |= DIFF_FORMAT_RAW;
2892        else if (!strcmp(arg, "--patch-with-raw"))
2893                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2894        else if (!strcmp(arg, "--numstat"))
2895                options->output_format |= DIFF_FORMAT_NUMSTAT;
2896        else if (!strcmp(arg, "--shortstat"))
2897                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2898        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2899                options->output_format |= DIFF_FORMAT_DIRSTAT;
2900        else if (!strcmp(arg, "--cumulative")) {
2901                options->output_format |= DIFF_FORMAT_DIRSTAT;
2902                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2903        } else if (opt_arg(arg, 0, "dirstat-by-file",
2904                           &options->dirstat_percent)) {
2905                options->output_format |= DIFF_FORMAT_DIRSTAT;
2906                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2907        }
2908        else if (!strcmp(arg, "--check"))
2909                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2910        else if (!strcmp(arg, "--summary"))
2911                options->output_format |= DIFF_FORMAT_SUMMARY;
2912        else if (!strcmp(arg, "--patch-with-stat"))
2913                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2914        else if (!strcmp(arg, "--name-only"))
2915                options->output_format |= DIFF_FORMAT_NAME;
2916        else if (!strcmp(arg, "--name-status"))
2917                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2918        else if (!strcmp(arg, "-s"))
2919                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2920        else if (!prefixcmp(arg, "--stat")) {
2921                char *end;
2922                int width = options->stat_width;
2923                int name_width = options->stat_name_width;
2924                arg += 6;
2925                end = (char *)arg;
2926
2927                switch (*arg) {
2928                case '-':
2929                        if (!prefixcmp(arg, "-width="))
2930                                width = strtoul(arg + 7, &end, 10);
2931                        else if (!prefixcmp(arg, "-name-width="))
2932                                name_width = strtoul(arg + 12, &end, 10);
2933                        break;
2934                case '=':
2935                        width = strtoul(arg+1, &end, 10);
2936                        if (*end == ',')
2937                                name_width = strtoul(end+1, &end, 10);
2938                }
2939
2940                /* Important! This checks all the error cases! */
2941                if (*end)
2942                        return 0;
2943                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2944                options->stat_name_width = name_width;
2945                options->stat_width = width;
2946        }
2947
2948        /* renames options */
2949        else if (!prefixcmp(arg, "-B")) {
2950                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2951                        return -1;
2952        }
2953        else if (!prefixcmp(arg, "-M")) {
2954                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2955                        return -1;
2956                options->detect_rename = DIFF_DETECT_RENAME;
2957        }
2958        else if (!prefixcmp(arg, "-C")) {
2959                if (options->detect_rename == DIFF_DETECT_COPY)
2960                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2961                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2962                        return -1;
2963                options->detect_rename = DIFF_DETECT_COPY;
2964        }
2965        else if (!strcmp(arg, "--no-renames"))
2966                options->detect_rename = 0;
2967        else if (!strcmp(arg, "--relative"))
2968                DIFF_OPT_SET(options, RELATIVE_NAME);
2969        else if (!prefixcmp(arg, "--relative=")) {
2970                DIFF_OPT_SET(options, RELATIVE_NAME);
2971                options->prefix = arg + 11;
2972        }
2973
2974        /* xdiff options */
2975        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2976                DIFF_XDL_SET(options, IGNORE_WHITESPACE);
2977        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2978                DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
2979        else if (!strcmp(arg, "--ignore-space-at-eol"))
2980                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
2981        else if (!strcmp(arg, "--patience"))
2982                DIFF_XDL_SET(options, PATIENCE_DIFF);
2983
2984        /* flags options */
2985        else if (!strcmp(arg, "--binary")) {
2986                options->output_format |= DIFF_FORMAT_PATCH;
2987                DIFF_OPT_SET(options, BINARY);
2988        }
2989        else if (!strcmp(arg, "--full-index"))
2990                DIFF_OPT_SET(options, FULL_INDEX);
2991        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2992                DIFF_OPT_SET(options, TEXT);
2993        else if (!strcmp(arg, "-R"))
2994                DIFF_OPT_SET(options, REVERSE_DIFF);
2995        else if (!strcmp(arg, "--find-copies-harder"))
2996                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2997        else if (!strcmp(arg, "--follow"))
2998                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2999        else if (!strcmp(arg, "--color"))
3000                DIFF_OPT_SET(options, COLOR_DIFF);
3001        else if (!prefixcmp(arg, "--color=")) {
3002                int value = git_config_colorbool(NULL, arg+8, -1);
3003                if (value == 0)
3004                        DIFF_OPT_CLR(options, COLOR_DIFF);
3005                else if (value > 0)
3006                        DIFF_OPT_SET(options, COLOR_DIFF);
3007                else
3008                        return error("option `color' expects \"always\", \"auto\", or \"never\"");
3009        }
3010        else if (!strcmp(arg, "--no-color"))
3011                DIFF_OPT_CLR(options, COLOR_DIFF);
3012        else if (!strcmp(arg, "--color-words")) {
3013                DIFF_OPT_SET(options, COLOR_DIFF);
3014                options->word_diff = DIFF_WORDS_COLOR;
3015        }
3016        else if (!prefixcmp(arg, "--color-words=")) {
3017                DIFF_OPT_SET(options, COLOR_DIFF);
3018                options->word_diff = DIFF_WORDS_COLOR;
3019                options->word_regex = arg + 14;
3020        }
3021        else if (!strcmp(arg, "--word-diff")) {
3022                if (options->word_diff == DIFF_WORDS_NONE)
3023                        options->word_diff = DIFF_WORDS_PLAIN;
3024        }
3025        else if (!prefixcmp(arg, "--word-diff=")) {
3026                const char *type = arg + 12;
3027                if (!strcmp(type, "plain"))
3028                        options->word_diff = DIFF_WORDS_PLAIN;
3029                else if (!strcmp(type, "color")) {
3030                        DIFF_OPT_SET(options, COLOR_DIFF);
3031                        options->word_diff = DIFF_WORDS_COLOR;
3032                }
3033                else if (!strcmp(type, "porcelain"))
3034                        options->word_diff = DIFF_WORDS_PORCELAIN;
3035                else if (!strcmp(type, "none"))
3036                        options->word_diff = DIFF_WORDS_NONE;
3037                else
3038                        die("bad --word-diff argument: %s", type);
3039        }
3040        else if (!prefixcmp(arg, "--word-diff-regex=")) {
3041                if (options->word_diff == DIFF_WORDS_NONE)
3042                        options->word_diff = DIFF_WORDS_PLAIN;
3043                options->word_regex = arg + 18;
3044        }
3045        else if (!strcmp(arg, "--exit-code"))
3046                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
3047        else if (!strcmp(arg, "--quiet"))
3048                DIFF_OPT_SET(options, QUICK);
3049        else if (!strcmp(arg, "--ext-diff"))
3050                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
3051        else if (!strcmp(arg, "--no-ext-diff"))
3052                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
3053        else if (!strcmp(arg, "--textconv"))
3054                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
3055        else if (!strcmp(arg, "--no-textconv"))
3056                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
3057        else if (!strcmp(arg, "--ignore-submodules"))
3058                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
3059        else if (!strcmp(arg, "--submodule"))
3060                DIFF_OPT_SET(options, SUBMODULE_LOG);
3061        else if (!prefixcmp(arg, "--submodule=")) {
3062                if (!strcmp(arg + 12, "log"))
3063                        DIFF_OPT_SET(options, SUBMODULE_LOG);
3064        }
3065
3066        /* misc options */
3067        else if (!strcmp(arg, "-z"))
3068                options->line_termination = 0;
3069        else if (!prefixcmp(arg, "-l"))
3070                options->rename_limit = strtoul(arg+2, NULL, 10);
3071        else if (!prefixcmp(arg, "-S"))
3072                options->pickaxe = arg + 2;
3073        else if (!strcmp(arg, "--pickaxe-all"))
3074                options->pickaxe_opts = DIFF_PICKAXE_ALL;
3075        else if (!strcmp(arg, "--pickaxe-regex"))
3076                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
3077        else if (!prefixcmp(arg, "-O"))
3078                options->orderfile = arg + 2;
3079        else if (!prefixcmp(arg, "--diff-filter="))
3080                options->filter = arg + 14;
3081        else if (!strcmp(arg, "--abbrev"))
3082                options->abbrev = DEFAULT_ABBREV;
3083        else if (!prefixcmp(arg, "--abbrev=")) {
3084                options->abbrev = strtoul(arg + 9, NULL, 10);
3085                if (options->abbrev < MINIMUM_ABBREV)
3086                        options->abbrev = MINIMUM_ABBREV;
3087                else if (40 < options->abbrev)
3088                        options->abbrev = 40;
3089        }
3090        else if (!prefixcmp(arg, "--src-prefix="))
3091                options->a_prefix = arg + 13;
3092        else if (!prefixcmp(arg, "--dst-prefix="))
3093                options->b_prefix = arg + 13;
3094        else if (!strcmp(arg, "--no-prefix"))
3095                options->a_prefix = options->b_prefix = "";
3096        else if (opt_arg(arg, '\0', "inter-hunk-context",
3097                         &options->interhunkcontext))
3098                ;
3099        else if (!prefixcmp(arg, "--output=")) {
3100                options->file = fopen(arg + strlen("--output="), "w");
3101                if (!options->file)
3102                        die_errno("Could not open '%s'", arg + strlen("--output="));
3103                options->close_file = 1;
3104        } else
3105                return 0;
3106        return 1;
3107}
3108
3109static int parse_num(const char **cp_p)
3110{
3111        unsigned long num, scale;
3112        int ch, dot;
3113        const char *cp = *cp_p;
3114
3115        num = 0;
3116        scale = 1;
3117        dot = 0;
3118        for (;;) {
3119                ch = *cp;
3120                if ( !dot && ch == '.' ) {
3121                        scale = 1;
3122                        dot = 1;
3123                } else if ( ch == '%' ) {
3124                        scale = dot ? scale*100 : 100;
3125                        cp++;   /* % is always at the end */
3126                        break;
3127                } else if ( ch >= '0' && ch <= '9' ) {
3128                        if ( scale < 100000 ) {
3129                                scale *= 10;
3130                                num = (num*10) + (ch-'0');
3131                        }
3132                } else {
3133                        break;
3134                }
3135                cp++;
3136        }
3137        *cp_p = cp;
3138
3139        /* user says num divided by scale and we say internally that
3140         * is MAX_SCORE * num / scale.
3141         */
3142        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
3143}
3144
3145static int diff_scoreopt_parse(const char *opt)
3146{
3147        int opt1, opt2, cmd;
3148
3149        if (*opt++ != '-')
3150                return -1;
3151        cmd = *opt++;
3152        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
3153                return -1; /* that is not a -M, -C nor -B option */
3154
3155        opt1 = parse_num(&opt);
3156        if (cmd != 'B')
3157                opt2 = 0;
3158        else {
3159                if (*opt == 0)
3160                        opt2 = 0;
3161                else if (*opt != '/')
3162                        return -1; /* we expect -B80/99 or -B80 */
3163                else {
3164                        opt++;
3165                        opt2 = parse_num(&opt);
3166                }
3167        }
3168        if (*opt != 0)
3169                return -1;
3170        return opt1 | (opt2 << 16);
3171}
3172
3173struct diff_queue_struct diff_queued_diff;
3174
3175void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
3176{
3177        if (queue->alloc <= queue->nr) {
3178                queue->alloc = alloc_nr(queue->alloc);
3179                queue->queue = xrealloc(queue->queue,
3180                                        sizeof(dp) * queue->alloc);
3181        }
3182        queue->queue[queue->nr++] = dp;
3183}
3184
3185struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
3186                                 struct diff_filespec *one,
3187                                 struct diff_filespec *two)
3188{
3189        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
3190        dp->one = one;
3191        dp->two = two;
3192        if (queue)
3193                diff_q(queue, dp);
3194        return dp;
3195}
3196
3197void diff_free_filepair(struct diff_filepair *p)
3198{
3199        free_filespec(p->one);
3200        free_filespec(p->two);
3201        free(p);
3202}
3203
3204/* This is different from find_unique_abbrev() in that
3205 * it stuffs the result with dots for alignment.
3206 */
3207const char *diff_unique_abbrev(const unsigned char *sha1, int len)
3208{
3209        int abblen;
3210        const char *abbrev;
3211        if (len == 40)
3212                return sha1_to_hex(sha1);
3213
3214        abbrev = find_unique_abbrev(sha1, len);
3215        abblen = strlen(abbrev);
3216        if (abblen < 37) {
3217                static char hex[41];
3218                if (len < abblen && abblen <= len + 2)
3219                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
3220                else
3221                        sprintf(hex, "%s...", abbrev);
3222                return hex;
3223        }
3224        return sha1_to_hex(sha1);
3225}
3226
3227static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
3228{
3229        int line_termination = opt->line_termination;
3230        int inter_name_termination = line_termination ? '\t' : '\0';
3231        if (opt->output_prefix) {
3232                struct strbuf *msg = NULL;
3233                msg = opt->output_prefix(opt, opt->output_prefix_data);
3234                fprintf(opt->file, "%s", msg->buf);
3235        }
3236
3237        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
3238                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
3239                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
3240                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
3241        }
3242        if (p->score) {
3243                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
3244                        inter_name_termination);
3245        } else {
3246                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
3247        }
3248
3249        if (p->status == DIFF_STATUS_COPIED ||
3250            p->status == DIFF_STATUS_RENAMED) {
3251                const char *name_a, *name_b;
3252                name_a = p->one->path;
3253                name_b = p->two->path;
3254                strip_prefix(opt->prefix_length, &name_a, &name_b);
3255                write_name_quoted(name_a, opt->file, inter_name_termination);
3256                write_name_quoted(name_b, opt->file, line_termination);
3257        } else {
3258                const char *name_a, *name_b;
3259                name_a = p->one->mode ? p->one->path : p->two->path;
3260                name_b = NULL;
3261                strip_prefix(opt->prefix_length, &name_a, &name_b);
3262                write_name_quoted(name_a, opt->file, line_termination);
3263        }
3264}
3265
3266int diff_unmodified_pair(struct diff_filepair *p)
3267{
3268        /* This function is written stricter than necessary to support
3269         * the currently implemented transformers, but the idea is to
3270         * let transformers to produce diff_filepairs any way they want,
3271         * and filter and clean them up here before producing the output.
3272         */
3273        struct diff_filespec *one = p->one, *two = p->two;
3274
3275        if (DIFF_PAIR_UNMERGED(p))
3276                return 0; /* unmerged is interesting */
3277
3278        /* deletion, addition, mode or type change
3279         * and rename are all interesting.
3280         */
3281        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
3282            DIFF_PAIR_MODE_CHANGED(p) ||
3283            strcmp(one->path, two->path))
3284                return 0;
3285
3286        /* both are valid and point at the same path.  that is, we are
3287         * dealing with a change.
3288         */
3289        if (one->sha1_valid && two->sha1_valid &&
3290            !hashcmp(one->sha1, two->sha1) &&
3291            !one->dirty_submodule && !two->dirty_submodule)
3292                return 1; /* no change */
3293        if (!one->sha1_valid && !two->sha1_valid)
3294                return 1; /* both look at the same file on the filesystem. */
3295        return 0;
3296}
3297
3298static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
3299{
3300        if (diff_unmodified_pair(p))
3301                return;
3302
3303        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3304            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3305                return; /* no tree diffs in patch format */
3306
3307        run_diff(p, o);
3308}
3309
3310static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
3311                            struct diffstat_t *diffstat)
3312{
3313        if (diff_unmodified_pair(p))
3314                return;
3315
3316        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3317            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3318                return; /* no tree diffs in patch format */
3319
3320        run_diffstat(p, o, diffstat);
3321}
3322
3323static void diff_flush_checkdiff(struct diff_filepair *p,
3324                struct diff_options *o)
3325{
3326        if (diff_unmodified_pair(p))
3327                return;
3328
3329        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3330            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3331                return; /* no tree diffs in patch format */
3332
3333        run_checkdiff(p, o);
3334}
3335
3336int diff_queue_is_empty(void)
3337{
3338        struct diff_queue_struct *q = &diff_queued_diff;
3339        int i;
3340        for (i = 0; i < q->nr; i++)
3341                if (!diff_unmodified_pair(q->queue[i]))
3342                        return 0;
3343        return 1;
3344}
3345
3346#if DIFF_DEBUG
3347void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
3348{
3349        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
3350                x, one ? one : "",
3351                s->path,
3352                DIFF_FILE_VALID(s) ? "valid" : "invalid",
3353                s->mode,
3354                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
3355        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
3356                x, one ? one : "",
3357                s->size, s->xfrm_flags);
3358}
3359
3360void diff_debug_filepair(const struct diff_filepair *p, int i)
3361{
3362        diff_debug_filespec(p->one, i, "one");
3363        diff_debug_filespec(p->two, i, "two");
3364        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
3365                p->score, p->status ? p->status : '?',
3366                p->one->rename_used, p->broken_pair);
3367}
3368
3369void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
3370{
3371        int i;
3372        if (msg)
3373                fprintf(stderr, "%s\n", msg);
3374        fprintf(stderr, "q->nr = %d\n", q->nr);
3375        for (i = 0; i < q->nr; i++) {
3376                struct diff_filepair *p = q->queue[i];
3377                diff_debug_filepair(p, i);
3378        }
3379}
3380#endif
3381
3382static void diff_resolve_rename_copy(void)
3383{
3384        int i;
3385        struct diff_filepair *p;
3386        struct diff_queue_struct *q = &diff_queued_diff;
3387
3388        diff_debug_queue("resolve-rename-copy", q);
3389
3390        for (i = 0; i < q->nr; i++) {
3391                p = q->queue[i];
3392                p->status = 0; /* undecided */
3393                if (DIFF_PAIR_UNMERGED(p))
3394                        p->status = DIFF_STATUS_UNMERGED;
3395                else if (!DIFF_FILE_VALID(p->one))
3396                        p->status = DIFF_STATUS_ADDED;
3397                else if (!DIFF_FILE_VALID(p->two))
3398                        p->status = DIFF_STATUS_DELETED;
3399                else if (DIFF_PAIR_TYPE_CHANGED(p))
3400                        p->status = DIFF_STATUS_TYPE_CHANGED;
3401
3402                /* from this point on, we are dealing with a pair
3403                 * whose both sides are valid and of the same type, i.e.
3404                 * either in-place edit or rename/copy edit.
3405                 */
3406                else if (DIFF_PAIR_RENAME(p)) {
3407                        /*
3408                         * A rename might have re-connected a broken
3409                         * pair up, causing the pathnames to be the
3410                         * same again. If so, that's not a rename at
3411                         * all, just a modification..
3412                         *
3413                         * Otherwise, see if this source was used for
3414                         * multiple renames, in which case we decrement
3415                         * the count, and call it a copy.
3416                         */
3417                        if (!strcmp(p->one->path, p->two->path))
3418                                p->status = DIFF_STATUS_MODIFIED;
3419                        else if (--p->one->rename_used > 0)
3420                                p->status = DIFF_STATUS_COPIED;
3421                        else
3422                                p->status = DIFF_STATUS_RENAMED;
3423                }
3424                else if (hashcmp(p->one->sha1, p->two->sha1) ||
3425                         p->one->mode != p->two->mode ||
3426                         p->one->dirty_submodule ||
3427                         p->two->dirty_submodule ||
3428                         is_null_sha1(p->one->sha1))
3429                        p->status = DIFF_STATUS_MODIFIED;
3430                else {
3431                        /* This is a "no-change" entry and should not
3432                         * happen anymore, but prepare for broken callers.
3433                         */
3434                        error("feeding unmodified %s to diffcore",
3435                              p->one->path);
3436                        p->status = DIFF_STATUS_UNKNOWN;
3437                }
3438        }
3439        diff_debug_queue("resolve-rename-copy done", q);
3440}
3441
3442static int check_pair_status(struct diff_filepair *p)
3443{
3444        switch (p->status) {
3445        case DIFF_STATUS_UNKNOWN:
3446                return 0;
3447        case 0:
3448                die("internal error in diff-resolve-rename-copy");
3449        default:
3450                return 1;
3451        }
3452}
3453
3454static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
3455{
3456        int fmt = opt->output_format;
3457
3458        if (fmt & DIFF_FORMAT_CHECKDIFF)
3459                diff_flush_checkdiff(p, opt);
3460        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
3461                diff_flush_raw(p, opt);
3462        else if (fmt & DIFF_FORMAT_NAME) {
3463                const char *name_a, *name_b;
3464                name_a = p->two->path;
3465                name_b = NULL;
3466                strip_prefix(opt->prefix_length, &name_a, &name_b);
3467                write_name_quoted(name_a, opt->file, opt->line_termination);
3468        }
3469}
3470
3471static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
3472{
3473        if (fs->mode)
3474                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
3475        else
3476                fprintf(file, " %s ", newdelete);
3477        write_name_quoted(fs->path, file, '\n');
3478}
3479
3480
3481static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
3482                const char *line_prefix)
3483{
3484        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
3485                fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
3486                        p->two->mode, show_name ? ' ' : '\n');
3487                if (show_name) {
3488                        write_name_quoted(p->two->path, file, '\n');
3489                }
3490        }
3491}
3492
3493static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
3494                        const char *line_prefix)
3495{
3496        char *names = pprint_rename(p->one->path, p->two->path);
3497
3498        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
3499        free(names);
3500        show_mode_change(file, p, 0, line_prefix);
3501}
3502
3503static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
3504{
3505        FILE *file = opt->file;
3506        char *line_prefix = "";
3507
3508        if (opt->output_prefix) {
3509                struct strbuf *buf = opt->output_prefix(opt, opt->output_prefix_data);
3510                line_prefix = buf->buf;
3511        }
3512
3513        switch(p->status) {
3514        case DIFF_STATUS_DELETED:
3515                fputs(line_prefix, file);
3516                show_file_mode_name(file, "delete", p->one);
3517                break;
3518        case DIFF_STATUS_ADDED:
3519                fputs(line_prefix, file);
3520                show_file_mode_name(file, "create", p->two);
3521                break;
3522        case DIFF_STATUS_COPIED:
3523                fputs(line_prefix, file);
3524                show_rename_copy(file, "copy", p, line_prefix);
3525                break;
3526        case DIFF_STATUS_RENAMED:
3527                fputs(line_prefix, file);
3528                show_rename_copy(file, "rename", p, line_prefix);
3529                break;
3530        default:
3531                if (p->score) {
3532                        fprintf(file, "%s rewrite ", line_prefix);
3533                        write_name_quoted(p->two->path, file, ' ');
3534                        fprintf(file, "(%d%%)\n", similarity_index(p));
3535                }
3536                show_mode_change(file, p, !p->score, line_prefix);
3537                break;
3538        }
3539}
3540
3541struct patch_id_t {
3542        git_SHA_CTX *ctx;
3543        int patchlen;
3544};
3545
3546static int remove_space(char *line, int len)
3547{
3548        int i;
3549        char *dst = line;
3550        unsigned char c;
3551
3552        for (i = 0; i < len; i++)
3553                if (!isspace((c = line[i])))
3554                        *dst++ = c;
3555
3556        return dst - line;
3557}
3558
3559static void patch_id_consume(void *priv, char *line, unsigned long len)
3560{
3561        struct patch_id_t *data = priv;
3562        int new_len;
3563
3564        /* Ignore line numbers when computing the SHA1 of the patch */
3565        if (!prefixcmp(line, "@@ -"))
3566                return;
3567
3568        new_len = remove_space(line, len);
3569
3570        git_SHA1_Update(data->ctx, line, new_len);
3571        data->patchlen += new_len;
3572}
3573
3574/* returns 0 upon success, and writes result into sha1 */
3575static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
3576{
3577        struct diff_queue_struct *q = &diff_queued_diff;
3578        int i;
3579        git_SHA_CTX ctx;
3580        struct patch_id_t data;
3581        char buffer[PATH_MAX * 4 + 20];
3582
3583        git_SHA1_Init(&ctx);
3584        memset(&data, 0, sizeof(struct patch_id_t));
3585        data.ctx = &ctx;
3586
3587        for (i = 0; i < q->nr; i++) {
3588                xpparam_t xpp;
3589                xdemitconf_t xecfg;
3590                mmfile_t mf1, mf2;
3591                struct diff_filepair *p = q->queue[i];
3592                int len1, len2;
3593
3594                memset(&xpp, 0, sizeof(xpp));
3595                memset(&xecfg, 0, sizeof(xecfg));
3596                if (p->status == 0)
3597                        return error("internal diff status error");
3598                if (p->status == DIFF_STATUS_UNKNOWN)
3599                        continue;
3600                if (diff_unmodified_pair(p))
3601                        continue;
3602                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3603                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3604                        continue;
3605                if (DIFF_PAIR_UNMERGED(p))
3606                        continue;
3607
3608                diff_fill_sha1_info(p->one);
3609                diff_fill_sha1_info(p->two);
3610                if (fill_mmfile(&mf1, p->one) < 0 ||
3611                                fill_mmfile(&mf2, p->two) < 0)
3612                        return error("unable to read files to diff");
3613
3614                len1 = remove_space(p->one->path, strlen(p->one->path));
3615                len2 = remove_space(p->two->path, strlen(p->two->path));
3616                if (p->one->mode == 0)
3617                        len1 = snprintf(buffer, sizeof(buffer),
3618                                        "diff--gita/%.*sb/%.*s"
3619                                        "newfilemode%06o"
3620                                        "---/dev/null"
3621                                        "+++b/%.*s",
3622                                        len1, p->one->path,
3623                                        len2, p->two->path,
3624                                        p->two->mode,
3625                                        len2, p->two->path);
3626                else if (p->two->mode == 0)
3627                        len1 = snprintf(buffer, sizeof(buffer),
3628                                        "diff--gita/%.*sb/%.*s"
3629                                        "deletedfilemode%06o"
3630                                        "---a/%.*s"
3631                                        "+++/dev/null",
3632                                        len1, p->one->path,
3633                                        len2, p->two->path,
3634                                        p->one->mode,
3635                                        len1, p->one->path);
3636                else
3637                        len1 = snprintf(buffer, sizeof(buffer),
3638                                        "diff--gita/%.*sb/%.*s"
3639                                        "---a/%.*s"
3640                                        "+++b/%.*s",
3641                                        len1, p->one->path,
3642                                        len2, p->two->path,
3643                                        len1, p->one->path,
3644                                        len2, p->two->path);
3645                git_SHA1_Update(&ctx, buffer, len1);
3646
3647                xpp.flags = XDF_NEED_MINIMAL;
3648                xecfg.ctxlen = 3;
3649                xecfg.flags = XDL_EMIT_FUNCNAMES;
3650                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3651                              &xpp, &xecfg);
3652        }
3653
3654        git_SHA1_Final(sha1, &ctx);
3655        return 0;
3656}
3657
3658int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3659{
3660        struct diff_queue_struct *q = &diff_queued_diff;
3661        int i;
3662        int result = diff_get_patch_id(options, sha1);
3663
3664        for (i = 0; i < q->nr; i++)
3665                diff_free_filepair(q->queue[i]);
3666
3667        free(q->queue);
3668        DIFF_QUEUE_CLEAR(q);
3669
3670        return result;
3671}
3672
3673static int is_summary_empty(const struct diff_queue_struct *q)
3674{
3675        int i;
3676
3677        for (i = 0; i < q->nr; i++) {
3678                const struct diff_filepair *p = q->queue[i];
3679
3680                switch (p->status) {
3681                case DIFF_STATUS_DELETED:
3682                case DIFF_STATUS_ADDED:
3683                case DIFF_STATUS_COPIED:
3684                case DIFF_STATUS_RENAMED:
3685                        return 0;
3686                default:
3687                        if (p->score)
3688                                return 0;
3689                        if (p->one->mode && p->two->mode &&
3690                            p->one->mode != p->two->mode)
3691                                return 0;
3692                        break;
3693                }
3694        }
3695        return 1;
3696}
3697
3698void diff_flush(struct diff_options *options)
3699{
3700        struct diff_queue_struct *q = &diff_queued_diff;
3701        int i, output_format = options->output_format;
3702        int separator = 0;
3703
3704        /*
3705         * Order: raw, stat, summary, patch
3706         * or:    name/name-status/checkdiff (other bits clear)
3707         */
3708        if (!q->nr)
3709                goto free_queue;
3710
3711        if (output_format & (DIFF_FORMAT_RAW |
3712                             DIFF_FORMAT_NAME |
3713                             DIFF_FORMAT_NAME_STATUS |
3714                             DIFF_FORMAT_CHECKDIFF)) {
3715                for (i = 0; i < q->nr; i++) {
3716                        struct diff_filepair *p = q->queue[i];
3717                        if (check_pair_status(p))
3718                                flush_one_pair(p, options);
3719                }
3720                separator++;
3721        }
3722
3723        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3724                struct diffstat_t diffstat;
3725
3726                memset(&diffstat, 0, sizeof(struct diffstat_t));
3727                for (i = 0; i < q->nr; i++) {
3728                        struct diff_filepair *p = q->queue[i];
3729                        if (check_pair_status(p))
3730                                diff_flush_stat(p, options, &diffstat);
3731                }
3732                if (output_format & DIFF_FORMAT_NUMSTAT)
3733                        show_numstat(&diffstat, options);
3734                if (output_format & DIFF_FORMAT_DIFFSTAT)
3735                        show_stats(&diffstat, options);
3736                if (output_format & DIFF_FORMAT_SHORTSTAT)
3737                        show_shortstats(&diffstat, options);
3738                free_diffstat_info(&diffstat);
3739                separator++;
3740        }
3741        if (output_format & DIFF_FORMAT_DIRSTAT)
3742                show_dirstat(options);
3743
3744        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3745                for (i = 0; i < q->nr; i++) {
3746                        diff_summary(options, q->queue[i]);
3747                }
3748                separator++;
3749        }
3750
3751        if (output_format & DIFF_FORMAT_NO_OUTPUT &&
3752            DIFF_OPT_TST(options, EXIT_WITH_STATUS) &&
3753            DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3754                /*
3755                 * run diff_flush_patch for the exit status. setting
3756                 * options->file to /dev/null should be safe, becaue we
3757                 * aren't supposed to produce any output anyway.
3758                 */
3759                if (options->close_file)
3760                        fclose(options->file);
3761                options->file = fopen("/dev/null", "w");
3762                if (!options->file)
3763                        die_errno("Could not open /dev/null");
3764                options->close_file = 1;
3765                for (i = 0; i < q->nr; i++) {
3766                        struct diff_filepair *p = q->queue[i];
3767                        if (check_pair_status(p))
3768                                diff_flush_patch(p, options);
3769                        if (options->found_changes)
3770                                break;
3771                }
3772        }
3773
3774        if (output_format & DIFF_FORMAT_PATCH) {
3775                if (separator) {
3776                        putc(options->line_termination, options->file);
3777                        if (options->stat_sep) {
3778                                /* attach patch instead of inline */
3779                                fputs(options->stat_sep, options->file);
3780                        }
3781                }
3782
3783                for (i = 0; i < q->nr; i++) {
3784                        struct diff_filepair *p = q->queue[i];
3785                        if (check_pair_status(p))
3786                                diff_flush_patch(p, options);
3787                }
3788        }
3789
3790        if (output_format & DIFF_FORMAT_CALLBACK)
3791                options->format_callback(q, options, options->format_callback_data);
3792
3793        for (i = 0; i < q->nr; i++)
3794                diff_free_filepair(q->queue[i]);
3795free_queue:
3796        free(q->queue);
3797        DIFF_QUEUE_CLEAR(q);
3798        if (options->close_file)
3799                fclose(options->file);
3800
3801        /*
3802         * Report the content-level differences with HAS_CHANGES;
3803         * diff_addremove/diff_change does not set the bit when
3804         * DIFF_FROM_CONTENTS is in effect (e.g. with -w).
3805         */
3806        if (DIFF_OPT_TST(options, DIFF_FROM_CONTENTS)) {
3807                if (options->found_changes)
3808                        DIFF_OPT_SET(options, HAS_CHANGES);
3809                else
3810                        DIFF_OPT_CLR(options, HAS_CHANGES);
3811        }
3812}
3813
3814static void diffcore_apply_filter(const char *filter)
3815{
3816        int i;
3817        struct diff_queue_struct *q = &diff_queued_diff;
3818        struct diff_queue_struct outq;
3819        DIFF_QUEUE_CLEAR(&outq);
3820
3821        if (!filter)
3822                return;
3823
3824        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3825                int found;
3826                for (i = found = 0; !found && i < q->nr; i++) {
3827                        struct diff_filepair *p = q->queue[i];
3828                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3829                             ((p->score &&
3830                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3831                              (!p->score &&
3832                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3833                            ((p->status != DIFF_STATUS_MODIFIED) &&
3834                             strchr(filter, p->status)))
3835                                found++;
3836                }
3837                if (found)
3838                        return;
3839
3840                /* otherwise we will clear the whole queue
3841                 * by copying the empty outq at the end of this
3842                 * function, but first clear the current entries
3843                 * in the queue.
3844                 */
3845                for (i = 0; i < q->nr; i++)
3846                        diff_free_filepair(q->queue[i]);
3847        }
3848        else {
3849                /* Only the matching ones */
3850                for (i = 0; i < q->nr; i++) {
3851                        struct diff_filepair *p = q->queue[i];
3852
3853                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3854                             ((p->score &&
3855                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3856                              (!p->score &&
3857                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3858                            ((p->status != DIFF_STATUS_MODIFIED) &&
3859                             strchr(filter, p->status)))
3860                                diff_q(&outq, p);
3861                        else
3862                                diff_free_filepair(p);
3863                }
3864        }
3865        free(q->queue);
3866        *q = outq;
3867}
3868
3869/* Check whether two filespecs with the same mode and size are identical */
3870static int diff_filespec_is_identical(struct diff_filespec *one,
3871                                      struct diff_filespec *two)
3872{
3873        if (S_ISGITLINK(one->mode))
3874                return 0;
3875        if (diff_populate_filespec(one, 0))
3876                return 0;
3877        if (diff_populate_filespec(two, 0))
3878                return 0;
3879        return !memcmp(one->data, two->data, one->size);
3880}
3881
3882static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3883{
3884        int i;
3885        struct diff_queue_struct *q = &diff_queued_diff;
3886        struct diff_queue_struct outq;
3887        DIFF_QUEUE_CLEAR(&outq);
3888
3889        for (i = 0; i < q->nr; i++) {
3890                struct diff_filepair *p = q->queue[i];
3891
3892                /*
3893                 * 1. Entries that come from stat info dirtiness
3894                 *    always have both sides (iow, not create/delete),
3895                 *    one side of the object name is unknown, with
3896                 *    the same mode and size.  Keep the ones that
3897                 *    do not match these criteria.  They have real
3898                 *    differences.
3899                 *
3900                 * 2. At this point, the file is known to be modified,
3901                 *    with the same mode and size, and the object
3902                 *    name of one side is unknown.  Need to inspect
3903                 *    the identical contents.
3904                 */
3905                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3906                    !DIFF_FILE_VALID(p->two) ||
3907                    (p->one->sha1_valid && p->two->sha1_valid) ||
3908                    (p->one->mode != p->two->mode) ||
3909                    diff_populate_filespec(p->one, 1) ||
3910                    diff_populate_filespec(p->two, 1) ||
3911                    (p->one->size != p->two->size) ||
3912                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3913                        diff_q(&outq, p);
3914                else {
3915                        /*
3916                         * The caller can subtract 1 from skip_stat_unmatch
3917                         * to determine how many paths were dirty only
3918                         * due to stat info mismatch.
3919                         */
3920                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3921                                diffopt->skip_stat_unmatch++;
3922                        diff_free_filepair(p);
3923                }
3924        }
3925        free(q->queue);
3926        *q = outq;
3927}
3928
3929static int diffnamecmp(const void *a_, const void *b_)
3930{
3931        const struct diff_filepair *a = *((const struct diff_filepair **)a_);
3932        const struct diff_filepair *b = *((const struct diff_filepair **)b_);
3933        const char *name_a, *name_b;
3934
3935        name_a = a->one ? a->one->path : a->two->path;
3936        name_b = b->one ? b->one->path : b->two->path;
3937        return strcmp(name_a, name_b);
3938}
3939
3940void diffcore_fix_diff_index(struct diff_options *options)
3941{
3942        struct diff_queue_struct *q = &diff_queued_diff;
3943        qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
3944}
3945
3946void diffcore_std(struct diff_options *options)
3947{
3948        /* We never run this function more than one time, because the
3949         * rename/copy detection logic can only run once.
3950         */
3951        if (diff_queued_diff.run)
3952                return;
3953
3954        if (options->skip_stat_unmatch)
3955                diffcore_skip_stat_unmatch(options);
3956        if (options->break_opt != -1)
3957                diffcore_break(options->break_opt);
3958        if (options->detect_rename)
3959                diffcore_rename(options);
3960        if (options->break_opt != -1)
3961                diffcore_merge_broken();
3962        if (options->pickaxe)
3963                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3964        if (options->orderfile)
3965                diffcore_order(options->orderfile);
3966        diff_resolve_rename_copy();
3967        diffcore_apply_filter(options->filter);
3968
3969        if (diff_queued_diff.nr && !DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
3970                DIFF_OPT_SET(options, HAS_CHANGES);
3971        else
3972                DIFF_OPT_CLR(options, HAS_CHANGES);
3973
3974        diff_queued_diff.run = 1;
3975}
3976
3977int diff_result_code(struct diff_options *opt, int status)
3978{
3979        int result = 0;
3980        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3981            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3982                return status;
3983        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3984            DIFF_OPT_TST(opt, HAS_CHANGES))
3985                result |= 01;
3986        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3987            DIFF_OPT_TST(opt, CHECK_FAILED))
3988                result |= 02;
3989        return result;
3990}
3991
3992void diff_addremove(struct diff_options *options,
3993                    int addremove, unsigned mode,
3994                    const unsigned char *sha1,
3995                    const char *concatpath, unsigned dirty_submodule)
3996{
3997        struct diff_filespec *one, *two;
3998
3999        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
4000                return;
4001
4002        /* This may look odd, but it is a preparation for
4003         * feeding "there are unchanged files which should
4004         * not produce diffs, but when you are doing copy
4005         * detection you would need them, so here they are"
4006         * entries to the diff-core.  They will be prefixed
4007         * with something like '=' or '*' (I haven't decided
4008         * which but should not make any difference).
4009         * Feeding the same new and old to diff_change()
4010         * also has the same effect.
4011         * Before the final output happens, they are pruned after
4012         * merged into rename/copy pairs as appropriate.
4013         */
4014        if (DIFF_OPT_TST(options, REVERSE_DIFF))
4015                addremove = (addremove == '+' ? '-' :
4016                             addremove == '-' ? '+' : addremove);
4017
4018        if (options->prefix &&
4019            strncmp(concatpath, options->prefix, options->prefix_length))
4020                return;
4021
4022        one = alloc_filespec(concatpath);
4023        two = alloc_filespec(concatpath);
4024
4025        if (addremove != '+')
4026                fill_filespec(one, sha1, mode);
4027        if (addremove != '-') {
4028                fill_filespec(two, sha1, mode);
4029                two->dirty_submodule = dirty_submodule;
4030        }
4031
4032        diff_queue(&diff_queued_diff, one, two);
4033        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4034                DIFF_OPT_SET(options, HAS_CHANGES);
4035}
4036
4037void diff_change(struct diff_options *options,
4038                 unsigned old_mode, unsigned new_mode,
4039                 const unsigned char *old_sha1,
4040                 const unsigned char *new_sha1,
4041                 const char *concatpath,
4042                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
4043{
4044        struct diff_filespec *one, *two;
4045
4046        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
4047                        && S_ISGITLINK(new_mode))
4048                return;
4049
4050        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
4051                unsigned tmp;
4052                const unsigned char *tmp_c;
4053                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
4054                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
4055                tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
4056                        new_dirty_submodule = tmp;
4057        }
4058
4059        if (options->prefix &&
4060            strncmp(concatpath, options->prefix, options->prefix_length))
4061                return;
4062
4063        one = alloc_filespec(concatpath);
4064        two = alloc_filespec(concatpath);
4065        fill_filespec(one, old_sha1, old_mode);
4066        fill_filespec(two, new_sha1, new_mode);
4067        one->dirty_submodule = old_dirty_submodule;
4068        two->dirty_submodule = new_dirty_submodule;
4069
4070        diff_queue(&diff_queued_diff, one, two);
4071        if (!DIFF_OPT_TST(options, DIFF_FROM_CONTENTS))
4072                DIFF_OPT_SET(options, HAS_CHANGES);
4073}
4074
4075void diff_unmerge(struct diff_options *options,
4076                  const char *path,
4077                  unsigned mode, const unsigned char *sha1)
4078{
4079        struct diff_filespec *one, *two;
4080
4081        if (options->prefix &&
4082            strncmp(path, options->prefix, options->prefix_length))
4083                return;
4084
4085        one = alloc_filespec(path);
4086        two = alloc_filespec(path);
4087        fill_filespec(one, sha1, mode);
4088        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
4089}
4090
4091static char *run_textconv(const char *pgm, struct diff_filespec *spec,
4092                size_t *outsize)
4093{
4094        struct diff_tempfile *temp;
4095        const char *argv[3];
4096        const char **arg = argv;
4097        struct child_process child;
4098        struct strbuf buf = STRBUF_INIT;
4099        int err = 0;
4100
4101        temp = prepare_temp_file(spec->path, spec);
4102        *arg++ = pgm;
4103        *arg++ = temp->name;
4104        *arg = NULL;
4105
4106        memset(&child, 0, sizeof(child));
4107        child.use_shell = 1;
4108        child.argv = argv;
4109        child.out = -1;
4110        if (start_command(&child)) {
4111                remove_tempfile();
4112                return NULL;
4113        }
4114
4115        if (strbuf_read(&buf, child.out, 0) < 0)
4116                err = error("error reading from textconv command '%s'", pgm);
4117        close(child.out);
4118
4119        if (finish_command(&child) || err) {
4120                strbuf_release(&buf);
4121                remove_tempfile();
4122                return NULL;
4123        }
4124        remove_tempfile();
4125
4126        return strbuf_detach(&buf, outsize);
4127}
4128
4129static size_t fill_textconv(struct userdiff_driver *driver,
4130                            struct diff_filespec *df,
4131                            char **outbuf)
4132{
4133        size_t size;
4134
4135        if (!driver || !driver->textconv) {
4136                if (!DIFF_FILE_VALID(df)) {
4137                        *outbuf = "";
4138                        return 0;
4139                }
4140                if (diff_populate_filespec(df, 0))
4141                        die("unable to read files to diff");
4142                *outbuf = df->data;
4143                return df->size;
4144        }
4145
4146        if (driver->textconv_cache) {
4147                *outbuf = notes_cache_get(driver->textconv_cache, df->sha1,
4148                                          &size);
4149                if (*outbuf)
4150                        return size;
4151        }
4152
4153        *outbuf = run_textconv(driver->textconv, df, &size);
4154        if (!*outbuf)
4155                die("unable to read files to diff");
4156
4157        if (driver->textconv_cache) {
4158                /* ignore errors, as we might be in a readonly repository */
4159                notes_cache_put(driver->textconv_cache, df->sha1, *outbuf,
4160                                size);
4161                /*
4162                 * we could save up changes and flush them all at the end,
4163                 * but we would need an extra call after all diffing is done.
4164                 * Since generating a cache entry is the slow path anyway,
4165                 * this extra overhead probably isn't a big deal.
4166                 */
4167                notes_cache_write(driver->textconv_cache);
4168        }
4169
4170        return size;
4171}