diff.con commit Merge branch 'ap/maint-apply-modefix' into maint (ae5a97f)
   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
  16#ifdef NO_FAST_WORKING_DIRECTORY
  17#define FAST_WORKING_DIRECTORY 0
  18#else
  19#define FAST_WORKING_DIRECTORY 1
  20#endif
  21
  22static int diff_detect_rename_default;
  23static int diff_rename_limit_default = 200;
  24static int diff_suppress_blank_empty;
  25int diff_use_color_default = -1;
  26static const char *external_diff_cmd_cfg;
  27int diff_auto_refresh_index = 1;
  28static int diff_mnemonic_prefix;
  29
  30static char diff_colors[][COLOR_MAXLEN] = {
  31        "\033[m",       /* reset */
  32        "",             /* PLAIN (normal) */
  33        "\033[1m",      /* METAINFO (bold) */
  34        "\033[36m",     /* FRAGINFO (cyan) */
  35        "\033[31m",     /* OLD (red) */
  36        "\033[32m",     /* NEW (green) */
  37        "\033[33m",     /* COMMIT (yellow) */
  38        "\033[41m",     /* WHITESPACE (red background) */
  39};
  40
  41static void diff_filespec_load_driver(struct diff_filespec *one);
  42static char *run_textconv(const char *, struct diff_filespec *, size_t *);
  43
  44static int parse_diff_color_slot(const char *var, int ofs)
  45{
  46        if (!strcasecmp(var+ofs, "plain"))
  47                return DIFF_PLAIN;
  48        if (!strcasecmp(var+ofs, "meta"))
  49                return DIFF_METAINFO;
  50        if (!strcasecmp(var+ofs, "frag"))
  51                return DIFF_FRAGINFO;
  52        if (!strcasecmp(var+ofs, "old"))
  53                return DIFF_FILE_OLD;
  54        if (!strcasecmp(var+ofs, "new"))
  55                return DIFF_FILE_NEW;
  56        if (!strcasecmp(var+ofs, "commit"))
  57                return DIFF_COMMIT;
  58        if (!strcasecmp(var+ofs, "whitespace"))
  59                return DIFF_WHITESPACE;
  60        die("bad config variable '%s'", var);
  61}
  62
  63/*
  64 * These are to give UI layer defaults.
  65 * The core-level commands such as git-diff-files should
  66 * never be affected by the setting of diff.renames
  67 * the user happens to have in the configuration file.
  68 */
  69int git_diff_ui_config(const char *var, const char *value, void *cb)
  70{
  71        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
  72                diff_use_color_default = git_config_colorbool(var, value, -1);
  73                return 0;
  74        }
  75        if (!strcmp(var, "diff.renames")) {
  76                if (!value)
  77                        diff_detect_rename_default = DIFF_DETECT_RENAME;
  78                else if (!strcasecmp(value, "copies") ||
  79                         !strcasecmp(value, "copy"))
  80                        diff_detect_rename_default = DIFF_DETECT_COPY;
  81                else if (git_config_bool(var,value))
  82                        diff_detect_rename_default = DIFF_DETECT_RENAME;
  83                return 0;
  84        }
  85        if (!strcmp(var, "diff.autorefreshindex")) {
  86                diff_auto_refresh_index = git_config_bool(var, value);
  87                return 0;
  88        }
  89        if (!strcmp(var, "diff.mnemonicprefix")) {
  90                diff_mnemonic_prefix = git_config_bool(var, value);
  91                return 0;
  92        }
  93        if (!strcmp(var, "diff.external"))
  94                return git_config_string(&external_diff_cmd_cfg, var, value);
  95
  96        return git_diff_basic_config(var, value, cb);
  97}
  98
  99int git_diff_basic_config(const char *var, const char *value, void *cb)
 100{
 101        if (!strcmp(var, "diff.renamelimit")) {
 102                diff_rename_limit_default = git_config_int(var, value);
 103                return 0;
 104        }
 105
 106        switch (userdiff_config(var, value)) {
 107                case 0: break;
 108                case -1: return -1;
 109                default: return 0;
 110        }
 111
 112        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 113                int slot = parse_diff_color_slot(var, 11);
 114                if (!value)
 115                        return config_error_nonbool(var);
 116                color_parse(value, var, diff_colors[slot]);
 117                return 0;
 118        }
 119
 120        /* like GNU diff's --suppress-blank-empty option  */
 121        if (!strcmp(var, "diff.suppress-blank-empty")) {
 122                diff_suppress_blank_empty = git_config_bool(var, value);
 123                return 0;
 124        }
 125
 126        return git_color_default_config(var, value, cb);
 127}
 128
 129static char *quote_two(const char *one, const char *two)
 130{
 131        int need_one = quote_c_style(one, NULL, NULL, 1);
 132        int need_two = quote_c_style(two, NULL, NULL, 1);
 133        struct strbuf res = STRBUF_INIT;
 134
 135        if (need_one + need_two) {
 136                strbuf_addch(&res, '"');
 137                quote_c_style(one, &res, NULL, 1);
 138                quote_c_style(two, &res, NULL, 1);
 139                strbuf_addch(&res, '"');
 140        } else {
 141                strbuf_addstr(&res, one);
 142                strbuf_addstr(&res, two);
 143        }
 144        return strbuf_detach(&res, NULL);
 145}
 146
 147static const char *external_diff(void)
 148{
 149        static const char *external_diff_cmd = NULL;
 150        static int done_preparing = 0;
 151
 152        if (done_preparing)
 153                return external_diff_cmd;
 154        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 155        if (!external_diff_cmd)
 156                external_diff_cmd = external_diff_cmd_cfg;
 157        done_preparing = 1;
 158        return external_diff_cmd;
 159}
 160
 161static struct diff_tempfile {
 162        const char *name; /* filename external diff should read from */
 163        char hex[41];
 164        char mode[10];
 165        char tmp_path[PATH_MAX];
 166} diff_temp[2];
 167
 168static int count_lines(const char *data, int size)
 169{
 170        int count, ch, completely_empty = 1, nl_just_seen = 0;
 171        count = 0;
 172        while (0 < size--) {
 173                ch = *data++;
 174                if (ch == '\n') {
 175                        count++;
 176                        nl_just_seen = 1;
 177                        completely_empty = 0;
 178                }
 179                else {
 180                        nl_just_seen = 0;
 181                        completely_empty = 0;
 182                }
 183        }
 184        if (completely_empty)
 185                return 0;
 186        if (!nl_just_seen)
 187                count++; /* no trailing newline */
 188        return count;
 189}
 190
 191static void print_line_count(FILE *file, int count)
 192{
 193        switch (count) {
 194        case 0:
 195                fprintf(file, "0,0");
 196                break;
 197        case 1:
 198                fprintf(file, "1");
 199                break;
 200        default:
 201                fprintf(file, "1,%d", count);
 202                break;
 203        }
 204}
 205
 206static void copy_file_with_prefix(FILE *file,
 207                                  int prefix, const char *data, int size,
 208                                  const char *set, const char *reset)
 209{
 210        int ch, nl_just_seen = 1;
 211        while (0 < size--) {
 212                ch = *data++;
 213                if (nl_just_seen) {
 214                        fputs(set, file);
 215                        putc(prefix, file);
 216                }
 217                if (ch == '\n') {
 218                        nl_just_seen = 1;
 219                        fputs(reset, file);
 220                } else
 221                        nl_just_seen = 0;
 222                putc(ch, file);
 223        }
 224        if (!nl_just_seen)
 225                fprintf(file, "%s\n\\ No newline at end of file\n", reset);
 226}
 227
 228static void emit_rewrite_diff(const char *name_a,
 229                              const char *name_b,
 230                              struct diff_filespec *one,
 231                              struct diff_filespec *two,
 232                              const char *textconv_one,
 233                              const char *textconv_two,
 234                              struct diff_options *o)
 235{
 236        int lc_a, lc_b;
 237        int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 238        const char *name_a_tab, *name_b_tab;
 239        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 240        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 241        const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
 242        const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
 243        const char *reset = diff_get_color(color_diff, DIFF_RESET);
 244        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 245        const char *a_prefix, *b_prefix;
 246        const char *data_one, *data_two;
 247        size_t size_one, size_two;
 248
 249        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
 250                a_prefix = o->b_prefix;
 251                b_prefix = o->a_prefix;
 252        } else {
 253                a_prefix = o->a_prefix;
 254                b_prefix = o->b_prefix;
 255        }
 256
 257        name_a += (*name_a == '/');
 258        name_b += (*name_b == '/');
 259        name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 260        name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 261
 262        strbuf_reset(&a_name);
 263        strbuf_reset(&b_name);
 264        quote_two_c_style(&a_name, a_prefix, name_a, 0);
 265        quote_two_c_style(&b_name, b_prefix, name_b, 0);
 266
 267        diff_populate_filespec(one, 0);
 268        diff_populate_filespec(two, 0);
 269        if (textconv_one) {
 270                data_one = run_textconv(textconv_one, one, &size_one);
 271                if (!data_one)
 272                        die("unable to read files to diff");
 273        }
 274        else {
 275                data_one = one->data;
 276                size_one = one->size;
 277        }
 278        if (textconv_two) {
 279                data_two = run_textconv(textconv_two, two, &size_two);
 280                if (!data_two)
 281                        die("unable to read files to diff");
 282        }
 283        else {
 284                data_two = two->data;
 285                size_two = two->size;
 286        }
 287
 288        lc_a = count_lines(data_one, size_one);
 289        lc_b = count_lines(data_two, size_two);
 290        fprintf(o->file,
 291                "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 292                metainfo, a_name.buf, name_a_tab, reset,
 293                metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 294        print_line_count(o->file, lc_a);
 295        fprintf(o->file, " +");
 296        print_line_count(o->file, lc_b);
 297        fprintf(o->file, " @@%s\n", reset);
 298        if (lc_a)
 299                copy_file_with_prefix(o->file, '-', data_one, size_one, old, reset);
 300        if (lc_b)
 301                copy_file_with_prefix(o->file, '+', data_two, size_two, new, reset);
 302}
 303
 304static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 305{
 306        if (!DIFF_FILE_VALID(one)) {
 307                mf->ptr = (char *)""; /* does not matter */
 308                mf->size = 0;
 309                return 0;
 310        }
 311        else if (diff_populate_filespec(one, 0))
 312                return -1;
 313
 314        mf->ptr = one->data;
 315        mf->size = one->size;
 316        return 0;
 317}
 318
 319struct diff_words_buffer {
 320        mmfile_t text;
 321        long alloc;
 322        long current; /* output pointer */
 323        int suppressed_newline;
 324};
 325
 326static void diff_words_append(char *line, unsigned long len,
 327                struct diff_words_buffer *buffer)
 328{
 329        if (buffer->text.size + len > buffer->alloc) {
 330                buffer->alloc = (buffer->text.size + len) * 3 / 2;
 331                buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
 332        }
 333        line++;
 334        len--;
 335        memcpy(buffer->text.ptr + buffer->text.size, line, len);
 336        buffer->text.size += len;
 337}
 338
 339struct diff_words_data {
 340        struct diff_words_buffer minus, plus;
 341        FILE *file;
 342};
 343
 344static void print_word(FILE *file, struct diff_words_buffer *buffer, int len, int color,
 345                int suppress_newline)
 346{
 347        const char *ptr;
 348        int eol = 0;
 349
 350        if (len == 0)
 351                return;
 352
 353        ptr  = buffer->text.ptr + buffer->current;
 354        buffer->current += len;
 355
 356        if (ptr[len - 1] == '\n') {
 357                eol = 1;
 358                len--;
 359        }
 360
 361        fputs(diff_get_color(1, color), file);
 362        fwrite(ptr, len, 1, file);
 363        fputs(diff_get_color(1, DIFF_RESET), file);
 364
 365        if (eol) {
 366                if (suppress_newline)
 367                        buffer->suppressed_newline = 1;
 368                else
 369                        putc('\n', file);
 370        }
 371}
 372
 373static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 374{
 375        struct diff_words_data *diff_words = priv;
 376
 377        if (diff_words->minus.suppressed_newline) {
 378                if (line[0] != '+')
 379                        putc('\n', diff_words->file);
 380                diff_words->minus.suppressed_newline = 0;
 381        }
 382
 383        len--;
 384        switch (line[0]) {
 385                case '-':
 386                        print_word(diff_words->file,
 387                                   &diff_words->minus, len, DIFF_FILE_OLD, 1);
 388                        break;
 389                case '+':
 390                        print_word(diff_words->file,
 391                                   &diff_words->plus, len, DIFF_FILE_NEW, 0);
 392                        break;
 393                case ' ':
 394                        print_word(diff_words->file,
 395                                   &diff_words->plus, len, DIFF_PLAIN, 0);
 396                        diff_words->minus.current += len;
 397                        break;
 398        }
 399}
 400
 401/* this executes the word diff on the accumulated buffers */
 402static void diff_words_show(struct diff_words_data *diff_words)
 403{
 404        xpparam_t xpp;
 405        xdemitconf_t xecfg;
 406        xdemitcb_t ecb;
 407        mmfile_t minus, plus;
 408        int i;
 409
 410        memset(&xpp, 0, sizeof(xpp));
 411        memset(&xecfg, 0, sizeof(xecfg));
 412        minus.size = diff_words->minus.text.size;
 413        minus.ptr = xmalloc(minus.size);
 414        memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
 415        for (i = 0; i < minus.size; i++)
 416                if (isspace(minus.ptr[i]))
 417                        minus.ptr[i] = '\n';
 418        diff_words->minus.current = 0;
 419
 420        plus.size = diff_words->plus.text.size;
 421        plus.ptr = xmalloc(plus.size);
 422        memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
 423        for (i = 0; i < plus.size; i++)
 424                if (isspace(plus.ptr[i]))
 425                        plus.ptr[i] = '\n';
 426        diff_words->plus.current = 0;
 427
 428        xpp.flags = XDF_NEED_MINIMAL;
 429        xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
 430        xdi_diff_outf(&minus, &plus, fn_out_diff_words_aux, diff_words,
 431                      &xpp, &xecfg, &ecb);
 432        free(minus.ptr);
 433        free(plus.ptr);
 434        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 435
 436        if (diff_words->minus.suppressed_newline) {
 437                putc('\n', diff_words->file);
 438                diff_words->minus.suppressed_newline = 0;
 439        }
 440}
 441
 442typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 443
 444struct emit_callback {
 445        int nparents, color_diff;
 446        unsigned ws_rule;
 447        sane_truncate_fn truncate;
 448        const char **label_path;
 449        struct diff_words_data *diff_words;
 450        int *found_changesp;
 451        FILE *file;
 452};
 453
 454static void free_diff_words_data(struct emit_callback *ecbdata)
 455{
 456        if (ecbdata->diff_words) {
 457                /* flush buffers */
 458                if (ecbdata->diff_words->minus.text.size ||
 459                                ecbdata->diff_words->plus.text.size)
 460                        diff_words_show(ecbdata->diff_words);
 461
 462                free (ecbdata->diff_words->minus.text.ptr);
 463                free (ecbdata->diff_words->plus.text.ptr);
 464                free(ecbdata->diff_words);
 465                ecbdata->diff_words = NULL;
 466        }
 467}
 468
 469const char *diff_get_color(int diff_use_color, enum color_diff ix)
 470{
 471        if (diff_use_color)
 472                return diff_colors[ix];
 473        return "";
 474}
 475
 476static void emit_line(FILE *file, const char *set, const char *reset, const char *line, int len)
 477{
 478        int has_trailing_newline, has_trailing_carriage_return;
 479
 480        has_trailing_newline = (len > 0 && line[len-1] == '\n');
 481        if (has_trailing_newline)
 482                len--;
 483        has_trailing_carriage_return = (len > 0 && line[len-1] == '\r');
 484        if (has_trailing_carriage_return)
 485                len--;
 486
 487        fputs(set, file);
 488        fwrite(line, len, 1, file);
 489        fputs(reset, file);
 490        if (has_trailing_carriage_return)
 491                fputc('\r', file);
 492        if (has_trailing_newline)
 493                fputc('\n', file);
 494}
 495
 496static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
 497{
 498        const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 499        const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 500
 501        if (!*ws)
 502                emit_line(ecbdata->file, set, reset, line, len);
 503        else {
 504                /* Emit just the prefix, then the rest. */
 505                emit_line(ecbdata->file, set, reset, line, ecbdata->nparents);
 506                ws_check_emit(line + ecbdata->nparents,
 507                              len - ecbdata->nparents, ecbdata->ws_rule,
 508                              ecbdata->file, set, reset, ws);
 509        }
 510}
 511
 512static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 513{
 514        const char *cp;
 515        unsigned long allot;
 516        size_t l = len;
 517
 518        if (ecb->truncate)
 519                return ecb->truncate(line, len);
 520        cp = line;
 521        allot = l;
 522        while (0 < l) {
 523                (void) utf8_width(&cp, &l);
 524                if (!cp)
 525                        break; /* truncated in the middle? */
 526        }
 527        return allot - l;
 528}
 529
 530static void fn_out_consume(void *priv, char *line, unsigned long len)
 531{
 532        int i;
 533        int color;
 534        struct emit_callback *ecbdata = priv;
 535        const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 536        const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 537        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 538
 539        *(ecbdata->found_changesp) = 1;
 540
 541        if (ecbdata->label_path[0]) {
 542                const char *name_a_tab, *name_b_tab;
 543
 544                name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 545                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 546
 547                fprintf(ecbdata->file, "%s--- %s%s%s\n",
 548                        meta, ecbdata->label_path[0], reset, name_a_tab);
 549                fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 550                        meta, ecbdata->label_path[1], reset, name_b_tab);
 551                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 552        }
 553
 554        if (diff_suppress_blank_empty
 555            && len == 2 && line[0] == ' ' && line[1] == '\n') {
 556                line[0] = '\n';
 557                len = 1;
 558        }
 559
 560        /* This is not really necessary for now because
 561         * this codepath only deals with two-way diffs.
 562         */
 563        for (i = 0; i < len && line[i] == '@'; i++)
 564                ;
 565        if (2 <= i && i < len && line[i] == ' ') {
 566                ecbdata->nparents = i - 1;
 567                len = sane_truncate_line(ecbdata, line, len);
 568                emit_line(ecbdata->file,
 569                          diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
 570                          reset, line, len);
 571                if (line[len-1] != '\n')
 572                        putc('\n', ecbdata->file);
 573                return;
 574        }
 575
 576        if (len < ecbdata->nparents) {
 577                emit_line(ecbdata->file, reset, reset, line, len);
 578                return;
 579        }
 580
 581        color = DIFF_PLAIN;
 582        if (ecbdata->diff_words && ecbdata->nparents != 1)
 583                /* fall back to normal diff */
 584                free_diff_words_data(ecbdata);
 585        if (ecbdata->diff_words) {
 586                if (line[0] == '-') {
 587                        diff_words_append(line, len,
 588                                          &ecbdata->diff_words->minus);
 589                        return;
 590                } else if (line[0] == '+') {
 591                        diff_words_append(line, len,
 592                                          &ecbdata->diff_words->plus);
 593                        return;
 594                }
 595                if (ecbdata->diff_words->minus.text.size ||
 596                    ecbdata->diff_words->plus.text.size)
 597                        diff_words_show(ecbdata->diff_words);
 598                line++;
 599                len--;
 600                emit_line(ecbdata->file, plain, reset, line, len);
 601                return;
 602        }
 603        for (i = 0; i < ecbdata->nparents && len; i++) {
 604                if (line[i] == '-')
 605                        color = DIFF_FILE_OLD;
 606                else if (line[i] == '+')
 607                        color = DIFF_FILE_NEW;
 608        }
 609
 610        if (color != DIFF_FILE_NEW) {
 611                emit_line(ecbdata->file,
 612                          diff_get_color(ecbdata->color_diff, color),
 613                          reset, line, len);
 614                return;
 615        }
 616        emit_add_line(reset, ecbdata, line, len);
 617}
 618
 619static char *pprint_rename(const char *a, const char *b)
 620{
 621        const char *old = a;
 622        const char *new = b;
 623        struct strbuf name = STRBUF_INIT;
 624        int pfx_length, sfx_length;
 625        int len_a = strlen(a);
 626        int len_b = strlen(b);
 627        int a_midlen, b_midlen;
 628        int qlen_a = quote_c_style(a, NULL, NULL, 0);
 629        int qlen_b = quote_c_style(b, NULL, NULL, 0);
 630
 631        if (qlen_a || qlen_b) {
 632                quote_c_style(a, &name, NULL, 0);
 633                strbuf_addstr(&name, " => ");
 634                quote_c_style(b, &name, NULL, 0);
 635                return strbuf_detach(&name, NULL);
 636        }
 637
 638        /* Find common prefix */
 639        pfx_length = 0;
 640        while (*old && *new && *old == *new) {
 641                if (*old == '/')
 642                        pfx_length = old - a + 1;
 643                old++;
 644                new++;
 645        }
 646
 647        /* Find common suffix */
 648        old = a + len_a;
 649        new = b + len_b;
 650        sfx_length = 0;
 651        while (a <= old && b <= new && *old == *new) {
 652                if (*old == '/')
 653                        sfx_length = len_a - (old - a);
 654                old--;
 655                new--;
 656        }
 657
 658        /*
 659         * pfx{mid-a => mid-b}sfx
 660         * {pfx-a => pfx-b}sfx
 661         * pfx{sfx-a => sfx-b}
 662         * name-a => name-b
 663         */
 664        a_midlen = len_a - pfx_length - sfx_length;
 665        b_midlen = len_b - pfx_length - sfx_length;
 666        if (a_midlen < 0)
 667                a_midlen = 0;
 668        if (b_midlen < 0)
 669                b_midlen = 0;
 670
 671        strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 672        if (pfx_length + sfx_length) {
 673                strbuf_add(&name, a, pfx_length);
 674                strbuf_addch(&name, '{');
 675        }
 676        strbuf_add(&name, a + pfx_length, a_midlen);
 677        strbuf_addstr(&name, " => ");
 678        strbuf_add(&name, b + pfx_length, b_midlen);
 679        if (pfx_length + sfx_length) {
 680                strbuf_addch(&name, '}');
 681                strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 682        }
 683        return strbuf_detach(&name, NULL);
 684}
 685
 686struct diffstat_t {
 687        int nr;
 688        int alloc;
 689        struct diffstat_file {
 690                char *from_name;
 691                char *name;
 692                char *print_name;
 693                unsigned is_unmerged:1;
 694                unsigned is_binary:1;
 695                unsigned is_renamed:1;
 696                unsigned int added, deleted;
 697        } **files;
 698};
 699
 700static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 701                                          const char *name_a,
 702                                          const char *name_b)
 703{
 704        struct diffstat_file *x;
 705        x = xcalloc(sizeof (*x), 1);
 706        if (diffstat->nr == diffstat->alloc) {
 707                diffstat->alloc = alloc_nr(diffstat->alloc);
 708                diffstat->files = xrealloc(diffstat->files,
 709                                diffstat->alloc * sizeof(x));
 710        }
 711        diffstat->files[diffstat->nr++] = x;
 712        if (name_b) {
 713                x->from_name = xstrdup(name_a);
 714                x->name = xstrdup(name_b);
 715                x->is_renamed = 1;
 716        }
 717        else {
 718                x->from_name = NULL;
 719                x->name = xstrdup(name_a);
 720        }
 721        return x;
 722}
 723
 724static void diffstat_consume(void *priv, char *line, unsigned long len)
 725{
 726        struct diffstat_t *diffstat = priv;
 727        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 728
 729        if (line[0] == '+')
 730                x->added++;
 731        else if (line[0] == '-')
 732                x->deleted++;
 733}
 734
 735const char mime_boundary_leader[] = "------------";
 736
 737static int scale_linear(int it, int width, int max_change)
 738{
 739        /*
 740         * make sure that at least one '-' is printed if there were deletions,
 741         * and likewise for '+'.
 742         */
 743        if (max_change < 2)
 744                return it;
 745        return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
 746}
 747
 748static void show_name(FILE *file,
 749                      const char *prefix, const char *name, int len,
 750                      const char *reset, const char *set)
 751{
 752        fprintf(file, " %s%s%-*s%s |", set, prefix, len, name, reset);
 753}
 754
 755static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
 756{
 757        if (cnt <= 0)
 758                return;
 759        fprintf(file, "%s", set);
 760        while (cnt--)
 761                putc(ch, file);
 762        fprintf(file, "%s", reset);
 763}
 764
 765static void fill_print_name(struct diffstat_file *file)
 766{
 767        char *pname;
 768
 769        if (file->print_name)
 770                return;
 771
 772        if (!file->is_renamed) {
 773                struct strbuf buf = STRBUF_INIT;
 774                if (quote_c_style(file->name, &buf, NULL, 0)) {
 775                        pname = strbuf_detach(&buf, NULL);
 776                } else {
 777                        pname = file->name;
 778                        strbuf_release(&buf);
 779                }
 780        } else {
 781                pname = pprint_rename(file->from_name, file->name);
 782        }
 783        file->print_name = pname;
 784}
 785
 786static void show_stats(struct diffstat_t* data, struct diff_options *options)
 787{
 788        int i, len, add, del, total, adds = 0, dels = 0;
 789        int max_change = 0, max_len = 0;
 790        int total_files = data->nr;
 791        int width, name_width;
 792        const char *reset, *set, *add_c, *del_c;
 793
 794        if (data->nr == 0)
 795                return;
 796
 797        width = options->stat_width ? options->stat_width : 80;
 798        name_width = options->stat_name_width ? options->stat_name_width : 50;
 799
 800        /* Sanity: give at least 5 columns to the graph,
 801         * but leave at least 10 columns for the name.
 802         */
 803        if (width < 25)
 804                width = 25;
 805        if (name_width < 10)
 806                name_width = 10;
 807        else if (width < name_width + 15)
 808                name_width = width - 15;
 809
 810        /* Find the longest filename and max number of changes */
 811        reset = diff_get_color_opt(options, DIFF_RESET);
 812        set   = diff_get_color_opt(options, DIFF_PLAIN);
 813        add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
 814        del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
 815
 816        for (i = 0; i < data->nr; i++) {
 817                struct diffstat_file *file = data->files[i];
 818                int change = file->added + file->deleted;
 819                fill_print_name(file);
 820                len = strlen(file->print_name);
 821                if (max_len < len)
 822                        max_len = len;
 823
 824                if (file->is_binary || file->is_unmerged)
 825                        continue;
 826                if (max_change < change)
 827                        max_change = change;
 828        }
 829
 830        /* Compute the width of the graph part;
 831         * 10 is for one blank at the beginning of the line plus
 832         * " | count " between the name and the graph.
 833         *
 834         * From here on, name_width is the width of the name area,
 835         * and width is the width of the graph area.
 836         */
 837        name_width = (name_width < max_len) ? name_width : max_len;
 838        if (width < (name_width + 10) + max_change)
 839                width = width - (name_width + 10);
 840        else
 841                width = max_change;
 842
 843        for (i = 0; i < data->nr; i++) {
 844                const char *prefix = "";
 845                char *name = data->files[i]->print_name;
 846                int added = data->files[i]->added;
 847                int deleted = data->files[i]->deleted;
 848                int name_len;
 849
 850                /*
 851                 * "scale" the filename
 852                 */
 853                len = name_width;
 854                name_len = strlen(name);
 855                if (name_width < name_len) {
 856                        char *slash;
 857                        prefix = "...";
 858                        len -= 3;
 859                        name += name_len - len;
 860                        slash = strchr(name, '/');
 861                        if (slash)
 862                                name = slash;
 863                }
 864
 865                if (data->files[i]->is_binary) {
 866                        show_name(options->file, prefix, name, len, reset, set);
 867                        fprintf(options->file, "  Bin ");
 868                        fprintf(options->file, "%s%d%s", del_c, deleted, reset);
 869                        fprintf(options->file, " -> ");
 870                        fprintf(options->file, "%s%d%s", add_c, added, reset);
 871                        fprintf(options->file, " bytes");
 872                        fprintf(options->file, "\n");
 873                        continue;
 874                }
 875                else if (data->files[i]->is_unmerged) {
 876                        show_name(options->file, prefix, name, len, reset, set);
 877                        fprintf(options->file, "  Unmerged\n");
 878                        continue;
 879                }
 880                else if (!data->files[i]->is_renamed &&
 881                         (added + deleted == 0)) {
 882                        total_files--;
 883                        continue;
 884                }
 885
 886                /*
 887                 * scale the add/delete
 888                 */
 889                add = added;
 890                del = deleted;
 891                total = add + del;
 892                adds += add;
 893                dels += del;
 894
 895                if (width <= max_change) {
 896                        add = scale_linear(add, width, max_change);
 897                        del = scale_linear(del, width, max_change);
 898                        total = add + del;
 899                }
 900                show_name(options->file, prefix, name, len, reset, set);
 901                fprintf(options->file, "%5d%s", added + deleted,
 902                                added + deleted ? " " : "");
 903                show_graph(options->file, '+', add, add_c, reset);
 904                show_graph(options->file, '-', del, del_c, reset);
 905                fprintf(options->file, "\n");
 906        }
 907        fprintf(options->file,
 908               "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
 909               set, total_files, adds, dels, reset);
 910}
 911
 912static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
 913{
 914        int i, adds = 0, dels = 0, total_files = data->nr;
 915
 916        if (data->nr == 0)
 917                return;
 918
 919        for (i = 0; i < data->nr; i++) {
 920                if (!data->files[i]->is_binary &&
 921                    !data->files[i]->is_unmerged) {
 922                        int added = data->files[i]->added;
 923                        int deleted= data->files[i]->deleted;
 924                        if (!data->files[i]->is_renamed &&
 925                            (added + deleted == 0)) {
 926                                total_files--;
 927                        } else {
 928                                adds += added;
 929                                dels += deleted;
 930                        }
 931                }
 932        }
 933        fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
 934               total_files, adds, dels);
 935}
 936
 937static void show_numstat(struct diffstat_t* data, struct diff_options *options)
 938{
 939        int i;
 940
 941        if (data->nr == 0)
 942                return;
 943
 944        for (i = 0; i < data->nr; i++) {
 945                struct diffstat_file *file = data->files[i];
 946
 947                if (file->is_binary)
 948                        fprintf(options->file, "-\t-\t");
 949                else
 950                        fprintf(options->file,
 951                                "%d\t%d\t", file->added, file->deleted);
 952                if (options->line_termination) {
 953                        fill_print_name(file);
 954                        if (!file->is_renamed)
 955                                write_name_quoted(file->name, options->file,
 956                                                  options->line_termination);
 957                        else {
 958                                fputs(file->print_name, options->file);
 959                                putc(options->line_termination, options->file);
 960                        }
 961                } else {
 962                        if (file->is_renamed) {
 963                                putc('\0', options->file);
 964                                write_name_quoted(file->from_name, options->file, '\0');
 965                        }
 966                        write_name_quoted(file->name, options->file, '\0');
 967                }
 968        }
 969}
 970
 971struct dirstat_file {
 972        const char *name;
 973        unsigned long changed;
 974};
 975
 976struct dirstat_dir {
 977        struct dirstat_file *files;
 978        int alloc, nr, percent, cumulative;
 979};
 980
 981static long gather_dirstat(FILE *file, struct dirstat_dir *dir, unsigned long changed, const char *base, int baselen)
 982{
 983        unsigned long this_dir = 0;
 984        unsigned int sources = 0;
 985
 986        while (dir->nr) {
 987                struct dirstat_file *f = dir->files;
 988                int namelen = strlen(f->name);
 989                unsigned long this;
 990                char *slash;
 991
 992                if (namelen < baselen)
 993                        break;
 994                if (memcmp(f->name, base, baselen))
 995                        break;
 996                slash = strchr(f->name + baselen, '/');
 997                if (slash) {
 998                        int newbaselen = slash + 1 - f->name;
 999                        this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1000                        sources++;
1001                } else {
1002                        this = f->changed;
1003                        dir->files++;
1004                        dir->nr--;
1005                        sources += 2;
1006                }
1007                this_dir += this;
1008        }
1009
1010        /*
1011         * We don't report dirstat's for
1012         *  - the top level
1013         *  - or cases where everything came from a single directory
1014         *    under this directory (sources == 1).
1015         */
1016        if (baselen && sources != 1) {
1017                int permille = this_dir * 1000 / changed;
1018                if (permille) {
1019                        int percent = permille / 10;
1020                        if (percent >= dir->percent) {
1021                                fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1022                                if (!dir->cumulative)
1023                                        return 0;
1024                        }
1025                }
1026        }
1027        return this_dir;
1028}
1029
1030static int dirstat_compare(const void *_a, const void *_b)
1031{
1032        const struct dirstat_file *a = _a;
1033        const struct dirstat_file *b = _b;
1034        return strcmp(a->name, b->name);
1035}
1036
1037static void show_dirstat(struct diff_options *options)
1038{
1039        int i;
1040        unsigned long changed;
1041        struct dirstat_dir dir;
1042        struct diff_queue_struct *q = &diff_queued_diff;
1043
1044        dir.files = NULL;
1045        dir.alloc = 0;
1046        dir.nr = 0;
1047        dir.percent = options->dirstat_percent;
1048        dir.cumulative = DIFF_OPT_TST(options, DIRSTAT_CUMULATIVE);
1049
1050        changed = 0;
1051        for (i = 0; i < q->nr; i++) {
1052                struct diff_filepair *p = q->queue[i];
1053                const char *name;
1054                unsigned long copied, added, damage;
1055
1056                name = p->one->path ? p->one->path : p->two->path;
1057
1058                if (DIFF_FILE_VALID(p->one) && DIFF_FILE_VALID(p->two)) {
1059                        diff_populate_filespec(p->one, 0);
1060                        diff_populate_filespec(p->two, 0);
1061                        diffcore_count_changes(p->one, p->two, NULL, NULL, 0,
1062                                               &copied, &added);
1063                        diff_free_filespec_data(p->one);
1064                        diff_free_filespec_data(p->two);
1065                } else if (DIFF_FILE_VALID(p->one)) {
1066                        diff_populate_filespec(p->one, 1);
1067                        copied = added = 0;
1068                        diff_free_filespec_data(p->one);
1069                } else if (DIFF_FILE_VALID(p->two)) {
1070                        diff_populate_filespec(p->two, 1);
1071                        copied = 0;
1072                        added = p->two->size;
1073                        diff_free_filespec_data(p->two);
1074                } else
1075                        continue;
1076
1077                /*
1078                 * Original minus copied is the removed material,
1079                 * added is the new material.  They are both damages
1080                 * made to the preimage. In --dirstat-by-file mode, count
1081                 * damaged files, not damaged lines. This is done by
1082                 * counting only a single damaged line per file.
1083                 */
1084                damage = (p->one->size - copied) + added;
1085                if (DIFF_OPT_TST(options, DIRSTAT_BY_FILE) && damage > 0)
1086                        damage = 1;
1087
1088                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
1089                dir.files[dir.nr].name = name;
1090                dir.files[dir.nr].changed = damage;
1091                changed += damage;
1092                dir.nr++;
1093        }
1094
1095        /* This can happen even with many files, if everything was renames */
1096        if (!changed)
1097                return;
1098
1099        /* Show all directories with more than x% of the changes */
1100        qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
1101        gather_dirstat(options->file, &dir, changed, "", 0);
1102}
1103
1104static void free_diffstat_info(struct diffstat_t *diffstat)
1105{
1106        int i;
1107        for (i = 0; i < diffstat->nr; i++) {
1108                struct diffstat_file *f = diffstat->files[i];
1109                if (f->name != f->print_name)
1110                        free(f->print_name);
1111                free(f->name);
1112                free(f->from_name);
1113                free(f);
1114        }
1115        free(diffstat->files);
1116}
1117
1118struct checkdiff_t {
1119        const char *filename;
1120        int lineno;
1121        struct diff_options *o;
1122        unsigned ws_rule;
1123        unsigned status;
1124        int trailing_blanks_start;
1125};
1126
1127static int is_conflict_marker(const char *line, unsigned long len)
1128{
1129        char firstchar;
1130        int cnt;
1131
1132        if (len < 8)
1133                return 0;
1134        firstchar = line[0];
1135        switch (firstchar) {
1136        case '=': case '>': case '<':
1137                break;
1138        default:
1139                return 0;
1140        }
1141        for (cnt = 1; cnt < 7; cnt++)
1142                if (line[cnt] != firstchar)
1143                        return 0;
1144        /* line[0] thru line[6] are same as firstchar */
1145        if (firstchar == '=') {
1146                /* divider between ours and theirs? */
1147                if (len != 8 || line[7] != '\n')
1148                        return 0;
1149        } else if (len < 8 || !isspace(line[7])) {
1150                /* not divider before ours nor after theirs */
1151                return 0;
1152        }
1153        return 1;
1154}
1155
1156static void checkdiff_consume(void *priv, char *line, unsigned long len)
1157{
1158        struct checkdiff_t *data = priv;
1159        int color_diff = DIFF_OPT_TST(data->o, COLOR_DIFF);
1160        const char *ws = diff_get_color(color_diff, DIFF_WHITESPACE);
1161        const char *reset = diff_get_color(color_diff, DIFF_RESET);
1162        const char *set = diff_get_color(color_diff, DIFF_FILE_NEW);
1163        char *err;
1164
1165        if (line[0] == '+') {
1166                unsigned bad;
1167                data->lineno++;
1168                if (!ws_blank_line(line + 1, len - 1, data->ws_rule))
1169                        data->trailing_blanks_start = 0;
1170                else if (!data->trailing_blanks_start)
1171                        data->trailing_blanks_start = data->lineno;
1172                if (is_conflict_marker(line + 1, len - 1)) {
1173                        data->status |= 1;
1174                        fprintf(data->o->file,
1175                                "%s:%d: leftover conflict marker\n",
1176                                data->filename, data->lineno);
1177                }
1178                bad = ws_check(line + 1, len - 1, data->ws_rule);
1179                if (!bad)
1180                        return;
1181                data->status |= bad;
1182                err = whitespace_error_string(bad);
1183                fprintf(data->o->file, "%s:%d: %s.\n",
1184                        data->filename, data->lineno, err);
1185                free(err);
1186                emit_line(data->o->file, set, reset, line, 1);
1187                ws_check_emit(line + 1, len - 1, data->ws_rule,
1188                              data->o->file, set, reset, ws);
1189        } else if (line[0] == ' ') {
1190                data->lineno++;
1191                data->trailing_blanks_start = 0;
1192        } else if (line[0] == '@') {
1193                char *plus = strchr(line, '+');
1194                if (plus)
1195                        data->lineno = strtol(plus, NULL, 10) - 1;
1196                else
1197                        die("invalid diff");
1198                data->trailing_blanks_start = 0;
1199        }
1200}
1201
1202static unsigned char *deflate_it(char *data,
1203                                 unsigned long size,
1204                                 unsigned long *result_size)
1205{
1206        int bound;
1207        unsigned char *deflated;
1208        z_stream stream;
1209
1210        memset(&stream, 0, sizeof(stream));
1211        deflateInit(&stream, zlib_compression_level);
1212        bound = deflateBound(&stream, size);
1213        deflated = xmalloc(bound);
1214        stream.next_out = deflated;
1215        stream.avail_out = bound;
1216
1217        stream.next_in = (unsigned char *)data;
1218        stream.avail_in = size;
1219        while (deflate(&stream, Z_FINISH) == Z_OK)
1220                ; /* nothing */
1221        deflateEnd(&stream);
1222        *result_size = stream.total_out;
1223        return deflated;
1224}
1225
1226static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1227{
1228        void *cp;
1229        void *delta;
1230        void *deflated;
1231        void *data;
1232        unsigned long orig_size;
1233        unsigned long delta_size;
1234        unsigned long deflate_size;
1235        unsigned long data_size;
1236
1237        /* We could do deflated delta, or we could do just deflated two,
1238         * whichever is smaller.
1239         */
1240        delta = NULL;
1241        deflated = deflate_it(two->ptr, two->size, &deflate_size);
1242        if (one->size && two->size) {
1243                delta = diff_delta(one->ptr, one->size,
1244                                   two->ptr, two->size,
1245                                   &delta_size, deflate_size);
1246                if (delta) {
1247                        void *to_free = delta;
1248                        orig_size = delta_size;
1249                        delta = deflate_it(delta, delta_size, &delta_size);
1250                        free(to_free);
1251                }
1252        }
1253
1254        if (delta && delta_size < deflate_size) {
1255                fprintf(file, "delta %lu\n", orig_size);
1256                free(deflated);
1257                data = delta;
1258                data_size = delta_size;
1259        }
1260        else {
1261                fprintf(file, "literal %lu\n", two->size);
1262                free(delta);
1263                data = deflated;
1264                data_size = deflate_size;
1265        }
1266
1267        /* emit data encoded in base85 */
1268        cp = data;
1269        while (data_size) {
1270                int bytes = (52 < data_size) ? 52 : data_size;
1271                char line[70];
1272                data_size -= bytes;
1273                if (bytes <= 26)
1274                        line[0] = bytes + 'A' - 1;
1275                else
1276                        line[0] = bytes - 26 + 'a' - 1;
1277                encode_85(line + 1, cp, bytes);
1278                cp = (char *) cp + bytes;
1279                fputs(line, file);
1280                fputc('\n', file);
1281        }
1282        fprintf(file, "\n");
1283        free(data);
1284}
1285
1286static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1287{
1288        fprintf(file, "GIT binary patch\n");
1289        emit_binary_diff_body(file, one, two);
1290        emit_binary_diff_body(file, two, one);
1291}
1292
1293static void diff_filespec_load_driver(struct diff_filespec *one)
1294{
1295        if (!one->driver)
1296                one->driver = userdiff_find_by_path(one->path);
1297        if (!one->driver)
1298                one->driver = userdiff_find_by_name("default");
1299}
1300
1301int diff_filespec_is_binary(struct diff_filespec *one)
1302{
1303        if (one->is_binary == -1) {
1304                diff_filespec_load_driver(one);
1305                if (one->driver->binary != -1)
1306                        one->is_binary = one->driver->binary;
1307                else {
1308                        if (!one->data && DIFF_FILE_VALID(one))
1309                                diff_populate_filespec(one, 0);
1310                        if (one->data)
1311                                one->is_binary = buffer_is_binary(one->data,
1312                                                one->size);
1313                        if (one->is_binary == -1)
1314                                one->is_binary = 0;
1315                }
1316        }
1317        return one->is_binary;
1318}
1319
1320static const struct userdiff_funcname *diff_funcname_pattern(struct diff_filespec *one)
1321{
1322        diff_filespec_load_driver(one);
1323        return one->driver->funcname.pattern ? &one->driver->funcname : NULL;
1324}
1325
1326void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b)
1327{
1328        if (!options->a_prefix)
1329                options->a_prefix = a;
1330        if (!options->b_prefix)
1331                options->b_prefix = b;
1332}
1333
1334static const char *get_textconv(struct diff_filespec *one)
1335{
1336        if (!DIFF_FILE_VALID(one))
1337                return NULL;
1338        if (!S_ISREG(one->mode))
1339                return NULL;
1340        diff_filespec_load_driver(one);
1341        return one->driver->textconv;
1342}
1343
1344static void builtin_diff(const char *name_a,
1345                         const char *name_b,
1346                         struct diff_filespec *one,
1347                         struct diff_filespec *two,
1348                         const char *xfrm_msg,
1349                         struct diff_options *o,
1350                         int complete_rewrite)
1351{
1352        mmfile_t mf1, mf2;
1353        const char *lbl[2];
1354        char *a_one, *b_two;
1355        const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1356        const char *reset = diff_get_color_opt(o, DIFF_RESET);
1357        const char *a_prefix, *b_prefix;
1358        const char *textconv_one = NULL, *textconv_two = NULL;
1359
1360        if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
1361                textconv_one = get_textconv(one);
1362                textconv_two = get_textconv(two);
1363        }
1364
1365        diff_set_mnemonic_prefix(o, "a/", "b/");
1366        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
1367                a_prefix = o->b_prefix;
1368                b_prefix = o->a_prefix;
1369        } else {
1370                a_prefix = o->a_prefix;
1371                b_prefix = o->b_prefix;
1372        }
1373
1374        /* Never use a non-valid filename anywhere if at all possible */
1375        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
1376        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
1377
1378        a_one = quote_two(a_prefix, name_a + (*name_a == '/'));
1379        b_two = quote_two(b_prefix, name_b + (*name_b == '/'));
1380        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1381        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1382        fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1383        if (lbl[0][0] == '/') {
1384                /* /dev/null */
1385                fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1386                if (xfrm_msg && xfrm_msg[0])
1387                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1388        }
1389        else if (lbl[1][0] == '/') {
1390                fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1391                if (xfrm_msg && xfrm_msg[0])
1392                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1393        }
1394        else {
1395                if (one->mode != two->mode) {
1396                        fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1397                        fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1398                }
1399                if (xfrm_msg && xfrm_msg[0])
1400                        fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1401                /*
1402                 * we do not run diff between different kind
1403                 * of objects.
1404                 */
1405                if ((one->mode ^ two->mode) & S_IFMT)
1406                        goto free_ab_and_return;
1407                if (complete_rewrite &&
1408                    (textconv_one || !diff_filespec_is_binary(one)) &&
1409                    (textconv_two || !diff_filespec_is_binary(two))) {
1410                        emit_rewrite_diff(name_a, name_b, one, two,
1411                                                textconv_one, textconv_two, o);
1412                        o->found_changes = 1;
1413                        goto free_ab_and_return;
1414                }
1415        }
1416
1417        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1418                die("unable to read files to diff");
1419
1420        if (!DIFF_OPT_TST(o, TEXT) &&
1421            ( (diff_filespec_is_binary(one) && !textconv_one) ||
1422              (diff_filespec_is_binary(two) && !textconv_two) )) {
1423                /* Quite common confusing case */
1424                if (mf1.size == mf2.size &&
1425                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1426                        goto free_ab_and_return;
1427                if (DIFF_OPT_TST(o, BINARY))
1428                        emit_binary_diff(o->file, &mf1, &mf2);
1429                else
1430                        fprintf(o->file, "Binary files %s and %s differ\n",
1431                                lbl[0], lbl[1]);
1432                o->found_changes = 1;
1433        }
1434        else {
1435                /* Crazy xdl interfaces.. */
1436                const char *diffopts = getenv("GIT_DIFF_OPTS");
1437                xpparam_t xpp;
1438                xdemitconf_t xecfg;
1439                xdemitcb_t ecb;
1440                struct emit_callback ecbdata;
1441                const struct userdiff_funcname *pe;
1442
1443                if (textconv_one) {
1444                        size_t size;
1445                        mf1.ptr = run_textconv(textconv_one, one, &size);
1446                        if (!mf1.ptr)
1447                                die("unable to read files to diff");
1448                        mf1.size = size;
1449                }
1450                if (textconv_two) {
1451                        size_t size;
1452                        mf2.ptr = run_textconv(textconv_two, two, &size);
1453                        if (!mf2.ptr)
1454                                die("unable to read files to diff");
1455                        mf2.size = size;
1456                }
1457
1458                pe = diff_funcname_pattern(one);
1459                if (!pe)
1460                        pe = diff_funcname_pattern(two);
1461
1462                memset(&xpp, 0, sizeof(xpp));
1463                memset(&xecfg, 0, sizeof(xecfg));
1464                memset(&ecbdata, 0, sizeof(ecbdata));
1465                ecbdata.label_path = lbl;
1466                ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1467                ecbdata.found_changesp = &o->found_changes;
1468                ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1469                ecbdata.file = o->file;
1470                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1471                xecfg.ctxlen = o->context;
1472                xecfg.flags = XDL_EMIT_FUNCNAMES;
1473                if (pe)
1474                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
1475                if (!diffopts)
1476                        ;
1477                else if (!prefixcmp(diffopts, "--unified="))
1478                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1479                else if (!prefixcmp(diffopts, "-u"))
1480                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1481                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1482                        ecbdata.diff_words =
1483                                xcalloc(1, sizeof(struct diff_words_data));
1484                        ecbdata.diff_words->file = o->file;
1485                }
1486                xdi_diff_outf(&mf1, &mf2, fn_out_consume, &ecbdata,
1487                              &xpp, &xecfg, &ecb);
1488                if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1489                        free_diff_words_data(&ecbdata);
1490                if (textconv_one)
1491                        free(mf1.ptr);
1492                if (textconv_two)
1493                        free(mf2.ptr);
1494        }
1495
1496 free_ab_and_return:
1497        diff_free_filespec_data(one);
1498        diff_free_filespec_data(two);
1499        free(a_one);
1500        free(b_two);
1501        return;
1502}
1503
1504static void builtin_diffstat(const char *name_a, const char *name_b,
1505                             struct diff_filespec *one,
1506                             struct diff_filespec *two,
1507                             struct diffstat_t *diffstat,
1508                             struct diff_options *o,
1509                             int complete_rewrite)
1510{
1511        mmfile_t mf1, mf2;
1512        struct diffstat_file *data;
1513
1514        data = diffstat_add(diffstat, name_a, name_b);
1515
1516        if (!one || !two) {
1517                data->is_unmerged = 1;
1518                return;
1519        }
1520        if (complete_rewrite) {
1521                diff_populate_filespec(one, 0);
1522                diff_populate_filespec(two, 0);
1523                data->deleted = count_lines(one->data, one->size);
1524                data->added = count_lines(two->data, two->size);
1525                goto free_and_return;
1526        }
1527        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1528                die("unable to read files to diff");
1529
1530        if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1531                data->is_binary = 1;
1532                data->added = mf2.size;
1533                data->deleted = mf1.size;
1534        } else {
1535                /* Crazy xdl interfaces.. */
1536                xpparam_t xpp;
1537                xdemitconf_t xecfg;
1538                xdemitcb_t ecb;
1539
1540                memset(&xpp, 0, sizeof(xpp));
1541                memset(&xecfg, 0, sizeof(xecfg));
1542                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1543                xdi_diff_outf(&mf1, &mf2, diffstat_consume, diffstat,
1544                              &xpp, &xecfg, &ecb);
1545        }
1546
1547 free_and_return:
1548        diff_free_filespec_data(one);
1549        diff_free_filespec_data(two);
1550}
1551
1552static void builtin_checkdiff(const char *name_a, const char *name_b,
1553                              const char *attr_path,
1554                              struct diff_filespec *one,
1555                              struct diff_filespec *two,
1556                              struct diff_options *o)
1557{
1558        mmfile_t mf1, mf2;
1559        struct checkdiff_t data;
1560
1561        if (!two)
1562                return;
1563
1564        memset(&data, 0, sizeof(data));
1565        data.filename = name_b ? name_b : name_a;
1566        data.lineno = 0;
1567        data.o = o;
1568        data.ws_rule = whitespace_rule(attr_path);
1569
1570        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1571                die("unable to read files to diff");
1572
1573        /*
1574         * All the other codepaths check both sides, but not checking
1575         * the "old" side here is deliberate.  We are checking the newly
1576         * introduced changes, and as long as the "new" side is text, we
1577         * can and should check what it introduces.
1578         */
1579        if (diff_filespec_is_binary(two))
1580                goto free_and_return;
1581        else {
1582                /* Crazy xdl interfaces.. */
1583                xpparam_t xpp;
1584                xdemitconf_t xecfg;
1585                xdemitcb_t ecb;
1586
1587                memset(&xpp, 0, sizeof(xpp));
1588                memset(&xecfg, 0, sizeof(xecfg));
1589                xecfg.ctxlen = 1; /* at least one context line */
1590                xpp.flags = XDF_NEED_MINIMAL;
1591                xdi_diff_outf(&mf1, &mf2, checkdiff_consume, &data,
1592                              &xpp, &xecfg, &ecb);
1593
1594                if ((data.ws_rule & WS_TRAILING_SPACE) &&
1595                    data.trailing_blanks_start) {
1596                        fprintf(o->file, "%s:%d: ends with blank lines.\n",
1597                                data.filename, data.trailing_blanks_start);
1598                        data.status = 1; /* report errors */
1599                }
1600        }
1601 free_and_return:
1602        diff_free_filespec_data(one);
1603        diff_free_filespec_data(two);
1604        if (data.status)
1605                DIFF_OPT_SET(o, CHECK_FAILED);
1606}
1607
1608struct diff_filespec *alloc_filespec(const char *path)
1609{
1610        int namelen = strlen(path);
1611        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1612
1613        memset(spec, 0, sizeof(*spec));
1614        spec->path = (char *)(spec + 1);
1615        memcpy(spec->path, path, namelen+1);
1616        spec->count = 1;
1617        spec->is_binary = -1;
1618        return spec;
1619}
1620
1621void free_filespec(struct diff_filespec *spec)
1622{
1623        if (!--spec->count) {
1624                diff_free_filespec_data(spec);
1625                free(spec);
1626        }
1627}
1628
1629void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1630                   unsigned short mode)
1631{
1632        if (mode) {
1633                spec->mode = canon_mode(mode);
1634                hashcpy(spec->sha1, sha1);
1635                spec->sha1_valid = !is_null_sha1(sha1);
1636        }
1637}
1638
1639/*
1640 * Given a name and sha1 pair, if the index tells us the file in
1641 * the work tree has that object contents, return true, so that
1642 * prepare_temp_file() does not have to inflate and extract.
1643 */
1644static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1645{
1646        struct cache_entry *ce;
1647        struct stat st;
1648        int pos, len;
1649
1650        /* We do not read the cache ourselves here, because the
1651         * benchmark with my previous version that always reads cache
1652         * shows that it makes things worse for diff-tree comparing
1653         * two linux-2.6 kernel trees in an already checked out work
1654         * tree.  This is because most diff-tree comparisons deal with
1655         * only a small number of files, while reading the cache is
1656         * expensive for a large project, and its cost outweighs the
1657         * savings we get by not inflating the object to a temporary
1658         * file.  Practically, this code only helps when we are used
1659         * by diff-cache --cached, which does read the cache before
1660         * calling us.
1661         */
1662        if (!active_cache)
1663                return 0;
1664
1665        /* We want to avoid the working directory if our caller
1666         * doesn't need the data in a normal file, this system
1667         * is rather slow with its stat/open/mmap/close syscalls,
1668         * and the object is contained in a pack file.  The pack
1669         * is probably already open and will be faster to obtain
1670         * the data through than the working directory.  Loose
1671         * objects however would tend to be slower as they need
1672         * to be individually opened and inflated.
1673         */
1674        if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1675                return 0;
1676
1677        len = strlen(name);
1678        pos = cache_name_pos(name, len);
1679        if (pos < 0)
1680                return 0;
1681        ce = active_cache[pos];
1682
1683        /*
1684         * This is not the sha1 we are looking for, or
1685         * unreusable because it is not a regular file.
1686         */
1687        if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1688                return 0;
1689
1690        /*
1691         * If ce matches the file in the work tree, we can reuse it.
1692         */
1693        if (ce_uptodate(ce) ||
1694            (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1695                return 1;
1696
1697        return 0;
1698}
1699
1700static int populate_from_stdin(struct diff_filespec *s)
1701{
1702        struct strbuf buf = STRBUF_INIT;
1703        size_t size = 0;
1704
1705        if (strbuf_read(&buf, 0, 0) < 0)
1706                return error("error while reading from stdin %s",
1707                                     strerror(errno));
1708
1709        s->should_munmap = 0;
1710        s->data = strbuf_detach(&buf, &size);
1711        s->size = size;
1712        s->should_free = 1;
1713        return 0;
1714}
1715
1716static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1717{
1718        int len;
1719        char *data = xmalloc(100);
1720        len = snprintf(data, 100,
1721                "Subproject commit %s\n", sha1_to_hex(s->sha1));
1722        s->data = data;
1723        s->size = len;
1724        s->should_free = 1;
1725        if (size_only) {
1726                s->data = NULL;
1727                free(data);
1728        }
1729        return 0;
1730}
1731
1732/*
1733 * While doing rename detection and pickaxe operation, we may need to
1734 * grab the data for the blob (or file) for our own in-core comparison.
1735 * diff_filespec has data and size fields for this purpose.
1736 */
1737int diff_populate_filespec(struct diff_filespec *s, int size_only)
1738{
1739        int err = 0;
1740        if (!DIFF_FILE_VALID(s))
1741                die("internal error: asking to populate invalid file.");
1742        if (S_ISDIR(s->mode))
1743                return -1;
1744
1745        if (s->data)
1746                return 0;
1747
1748        if (size_only && 0 < s->size)
1749                return 0;
1750
1751        if (S_ISGITLINK(s->mode))
1752                return diff_populate_gitlink(s, size_only);
1753
1754        if (!s->sha1_valid ||
1755            reuse_worktree_file(s->path, s->sha1, 0)) {
1756                struct strbuf buf = STRBUF_INIT;
1757                struct stat st;
1758                int fd;
1759
1760                if (!strcmp(s->path, "-"))
1761                        return populate_from_stdin(s);
1762
1763                if (lstat(s->path, &st) < 0) {
1764                        if (errno == ENOENT) {
1765                        err_empty:
1766                                err = -1;
1767                        empty:
1768                                s->data = (char *)"";
1769                                s->size = 0;
1770                                return err;
1771                        }
1772                }
1773                s->size = xsize_t(st.st_size);
1774                if (!s->size)
1775                        goto empty;
1776                if (S_ISLNK(st.st_mode)) {
1777                        struct strbuf sb = STRBUF_INIT;
1778
1779                        if (strbuf_readlink(&sb, s->path, s->size))
1780                                goto err_empty;
1781                        s->size = sb.len;
1782                        s->data = strbuf_detach(&sb, NULL);
1783                        s->should_free = 1;
1784                        return 0;
1785                }
1786                if (size_only)
1787                        return 0;
1788                fd = open(s->path, O_RDONLY);
1789                if (fd < 0)
1790                        goto err_empty;
1791                s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1792                close(fd);
1793                s->should_munmap = 1;
1794
1795                /*
1796                 * Convert from working tree format to canonical git format
1797                 */
1798                if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
1799                        size_t size = 0;
1800                        munmap(s->data, s->size);
1801                        s->should_munmap = 0;
1802                        s->data = strbuf_detach(&buf, &size);
1803                        s->size = size;
1804                        s->should_free = 1;
1805                }
1806        }
1807        else {
1808                enum object_type type;
1809                if (size_only)
1810                        type = sha1_object_info(s->sha1, &s->size);
1811                else {
1812                        s->data = read_sha1_file(s->sha1, &type, &s->size);
1813                        s->should_free = 1;
1814                }
1815        }
1816        return 0;
1817}
1818
1819void diff_free_filespec_blob(struct diff_filespec *s)
1820{
1821        if (s->should_free)
1822                free(s->data);
1823        else if (s->should_munmap)
1824                munmap(s->data, s->size);
1825
1826        if (s->should_free || s->should_munmap) {
1827                s->should_free = s->should_munmap = 0;
1828                s->data = NULL;
1829        }
1830}
1831
1832void diff_free_filespec_data(struct diff_filespec *s)
1833{
1834        diff_free_filespec_blob(s);
1835        free(s->cnt_data);
1836        s->cnt_data = NULL;
1837}
1838
1839static void prep_temp_blob(struct diff_tempfile *temp,
1840                           void *blob,
1841                           unsigned long size,
1842                           const unsigned char *sha1,
1843                           int mode)
1844{
1845        int fd;
1846
1847        fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1848        if (fd < 0)
1849                die("unable to create temp-file: %s", strerror(errno));
1850        if (write_in_full(fd, blob, size) != size)
1851                die("unable to write temp-file");
1852        close(fd);
1853        temp->name = temp->tmp_path;
1854        strcpy(temp->hex, sha1_to_hex(sha1));
1855        temp->hex[40] = 0;
1856        sprintf(temp->mode, "%06o", mode);
1857}
1858
1859static void prepare_temp_file(const char *name,
1860                              struct diff_tempfile *temp,
1861                              struct diff_filespec *one)
1862{
1863        if (!DIFF_FILE_VALID(one)) {
1864        not_a_valid_file:
1865                /* A '-' entry produces this for file-2, and
1866                 * a '+' entry produces this for file-1.
1867                 */
1868                temp->name = "/dev/null";
1869                strcpy(temp->hex, ".");
1870                strcpy(temp->mode, ".");
1871                return;
1872        }
1873
1874        if (!one->sha1_valid ||
1875            reuse_worktree_file(name, one->sha1, 1)) {
1876                struct stat st;
1877                if (lstat(name, &st) < 0) {
1878                        if (errno == ENOENT)
1879                                goto not_a_valid_file;
1880                        die("stat(%s): %s", name, strerror(errno));
1881                }
1882                if (S_ISLNK(st.st_mode)) {
1883                        int ret;
1884                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1885                        ret = readlink(name, buf, sizeof(buf));
1886                        if (ret < 0)
1887                                die("readlink(%s)", name);
1888                        if (ret == sizeof(buf))
1889                                die("symlink too long: %s", name);
1890                        prep_temp_blob(temp, buf, ret,
1891                                       (one->sha1_valid ?
1892                                        one->sha1 : null_sha1),
1893                                       (one->sha1_valid ?
1894                                        one->mode : S_IFLNK));
1895                }
1896                else {
1897                        /* we can borrow from the file in the work tree */
1898                        temp->name = name;
1899                        if (!one->sha1_valid)
1900                                strcpy(temp->hex, sha1_to_hex(null_sha1));
1901                        else
1902                                strcpy(temp->hex, sha1_to_hex(one->sha1));
1903                        /* Even though we may sometimes borrow the
1904                         * contents from the work tree, we always want
1905                         * one->mode.  mode is trustworthy even when
1906                         * !(one->sha1_valid), as long as
1907                         * DIFF_FILE_VALID(one).
1908                         */
1909                        sprintf(temp->mode, "%06o", one->mode);
1910                }
1911                return;
1912        }
1913        else {
1914                if (diff_populate_filespec(one, 0))
1915                        die("cannot read data blob for %s", one->path);
1916                prep_temp_blob(temp, one->data, one->size,
1917                               one->sha1, one->mode);
1918        }
1919}
1920
1921static void remove_tempfile(void)
1922{
1923        int i;
1924
1925        for (i = 0; i < 2; i++)
1926                if (diff_temp[i].name == diff_temp[i].tmp_path) {
1927                        unlink(diff_temp[i].name);
1928                        diff_temp[i].name = NULL;
1929                }
1930}
1931
1932static void remove_tempfile_on_signal(int signo)
1933{
1934        remove_tempfile();
1935        signal(SIGINT, SIG_DFL);
1936        raise(signo);
1937}
1938
1939/* An external diff command takes:
1940 *
1941 * diff-cmd name infile1 infile1-sha1 infile1-mode \
1942 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1943 *
1944 */
1945static void run_external_diff(const char *pgm,
1946                              const char *name,
1947                              const char *other,
1948                              struct diff_filespec *one,
1949                              struct diff_filespec *two,
1950                              const char *xfrm_msg,
1951                              int complete_rewrite)
1952{
1953        const char *spawn_arg[10];
1954        struct diff_tempfile *temp = diff_temp;
1955        int retval;
1956        static int atexit_asked = 0;
1957        const char *othername;
1958        const char **arg = &spawn_arg[0];
1959
1960        othername = (other? other : name);
1961        if (one && two) {
1962                prepare_temp_file(name, &temp[0], one);
1963                prepare_temp_file(othername, &temp[1], two);
1964                if (! atexit_asked &&
1965                    (temp[0].name == temp[0].tmp_path ||
1966                     temp[1].name == temp[1].tmp_path)) {
1967                        atexit_asked = 1;
1968                        atexit(remove_tempfile);
1969                }
1970                signal(SIGINT, remove_tempfile_on_signal);
1971        }
1972
1973        if (one && two) {
1974                *arg++ = pgm;
1975                *arg++ = name;
1976                *arg++ = temp[0].name;
1977                *arg++ = temp[0].hex;
1978                *arg++ = temp[0].mode;
1979                *arg++ = temp[1].name;
1980                *arg++ = temp[1].hex;
1981                *arg++ = temp[1].mode;
1982                if (other) {
1983                        *arg++ = other;
1984                        *arg++ = xfrm_msg;
1985                }
1986        } else {
1987                *arg++ = pgm;
1988                *arg++ = name;
1989        }
1990        *arg = NULL;
1991        fflush(NULL);
1992        retval = run_command_v_opt(spawn_arg, 0);
1993        remove_tempfile();
1994        if (retval) {
1995                fprintf(stderr, "external diff died, stopping at %s.\n", name);
1996                exit(1);
1997        }
1998}
1999
2000static void run_diff_cmd(const char *pgm,
2001                         const char *name,
2002                         const char *other,
2003                         const char *attr_path,
2004                         struct diff_filespec *one,
2005                         struct diff_filespec *two,
2006                         const char *xfrm_msg,
2007                         struct diff_options *o,
2008                         int complete_rewrite)
2009{
2010        if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
2011                pgm = NULL;
2012        else {
2013                struct userdiff_driver *drv = userdiff_find_by_path(attr_path);
2014                if (drv && drv->external)
2015                        pgm = drv->external;
2016        }
2017
2018        if (pgm) {
2019                run_external_diff(pgm, name, other, one, two, xfrm_msg,
2020                                  complete_rewrite);
2021                return;
2022        }
2023        if (one && two)
2024                builtin_diff(name, other ? other : name,
2025                             one, two, xfrm_msg, o, complete_rewrite);
2026        else
2027                fprintf(o->file, "* Unmerged path %s\n", name);
2028}
2029
2030static void diff_fill_sha1_info(struct diff_filespec *one)
2031{
2032        if (DIFF_FILE_VALID(one)) {
2033                if (!one->sha1_valid) {
2034                        struct stat st;
2035                        if (!strcmp(one->path, "-")) {
2036                                hashcpy(one->sha1, null_sha1);
2037                                return;
2038                        }
2039                        if (lstat(one->path, &st) < 0)
2040                                die("stat %s", one->path);
2041                        if (index_path(one->sha1, one->path, &st, 0))
2042                                die("cannot hash %s\n", one->path);
2043                }
2044        }
2045        else
2046                hashclr(one->sha1);
2047}
2048
2049static int similarity_index(struct diff_filepair *p)
2050{
2051        return p->score * 100 / MAX_SCORE;
2052}
2053
2054static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2055{
2056        /* Strip the prefix but do not molest /dev/null and absolute paths */
2057        if (*namep && **namep != '/')
2058                *namep += prefix_length;
2059        if (*otherp && **otherp != '/')
2060                *otherp += prefix_length;
2061}
2062
2063static void run_diff(struct diff_filepair *p, struct diff_options *o)
2064{
2065        const char *pgm = external_diff();
2066        struct strbuf msg;
2067        char *xfrm_msg;
2068        struct diff_filespec *one = p->one;
2069        struct diff_filespec *two = p->two;
2070        const char *name;
2071        const char *other;
2072        const char *attr_path;
2073        int complete_rewrite = 0;
2074
2075        name  = p->one->path;
2076        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2077        attr_path = name;
2078        if (o->prefix_length)
2079                strip_prefix(o->prefix_length, &name, &other);
2080
2081        if (DIFF_PAIR_UNMERGED(p)) {
2082                run_diff_cmd(pgm, name, NULL, attr_path,
2083                             NULL, NULL, NULL, o, 0);
2084                return;
2085        }
2086
2087        diff_fill_sha1_info(one);
2088        diff_fill_sha1_info(two);
2089
2090        strbuf_init(&msg, PATH_MAX * 2 + 300);
2091        switch (p->status) {
2092        case DIFF_STATUS_COPIED:
2093                strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2094                strbuf_addstr(&msg, "\ncopy from ");
2095                quote_c_style(name, &msg, NULL, 0);
2096                strbuf_addstr(&msg, "\ncopy to ");
2097                quote_c_style(other, &msg, NULL, 0);
2098                strbuf_addch(&msg, '\n');
2099                break;
2100        case DIFF_STATUS_RENAMED:
2101                strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2102                strbuf_addstr(&msg, "\nrename from ");
2103                quote_c_style(name, &msg, NULL, 0);
2104                strbuf_addstr(&msg, "\nrename to ");
2105                quote_c_style(other, &msg, NULL, 0);
2106                strbuf_addch(&msg, '\n');
2107                break;
2108        case DIFF_STATUS_MODIFIED:
2109                if (p->score) {
2110                        strbuf_addf(&msg, "dissimilarity index %d%%\n",
2111                                        similarity_index(p));
2112                        complete_rewrite = 1;
2113                        break;
2114                }
2115                /* fallthru */
2116        default:
2117                /* nothing */
2118                ;
2119        }
2120
2121        if (hashcmp(one->sha1, two->sha1)) {
2122                int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2123
2124                if (DIFF_OPT_TST(o, BINARY)) {
2125                        mmfile_t mf;
2126                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2127                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2128                                abbrev = 40;
2129                }
2130                strbuf_addf(&msg, "index %.*s..%.*s",
2131                                abbrev, sha1_to_hex(one->sha1),
2132                                abbrev, sha1_to_hex(two->sha1));
2133                if (one->mode == two->mode)
2134                        strbuf_addf(&msg, " %06o", one->mode);
2135                strbuf_addch(&msg, '\n');
2136        }
2137
2138        if (msg.len)
2139                strbuf_setlen(&msg, msg.len - 1);
2140        xfrm_msg = msg.len ? msg.buf : NULL;
2141
2142        if (!pgm &&
2143            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2144            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2145                /* a filepair that changes between file and symlink
2146                 * needs to be split into deletion and creation.
2147                 */
2148                struct diff_filespec *null = alloc_filespec(two->path);
2149                run_diff_cmd(NULL, name, other, attr_path,
2150                             one, null, xfrm_msg, o, 0);
2151                free(null);
2152                null = alloc_filespec(one->path);
2153                run_diff_cmd(NULL, name, other, attr_path,
2154                             null, two, xfrm_msg, o, 0);
2155                free(null);
2156        }
2157        else
2158                run_diff_cmd(pgm, name, other, attr_path,
2159                             one, two, xfrm_msg, o, complete_rewrite);
2160
2161        strbuf_release(&msg);
2162}
2163
2164static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2165                         struct diffstat_t *diffstat)
2166{
2167        const char *name;
2168        const char *other;
2169        int complete_rewrite = 0;
2170
2171        if (DIFF_PAIR_UNMERGED(p)) {
2172                /* unmerged */
2173                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2174                return;
2175        }
2176
2177        name = p->one->path;
2178        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2179
2180        if (o->prefix_length)
2181                strip_prefix(o->prefix_length, &name, &other);
2182
2183        diff_fill_sha1_info(p->one);
2184        diff_fill_sha1_info(p->two);
2185
2186        if (p->status == DIFF_STATUS_MODIFIED && p->score)
2187                complete_rewrite = 1;
2188        builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2189}
2190
2191static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2192{
2193        const char *name;
2194        const char *other;
2195        const char *attr_path;
2196
2197        if (DIFF_PAIR_UNMERGED(p)) {
2198                /* unmerged */
2199                return;
2200        }
2201
2202        name = p->one->path;
2203        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2204        attr_path = other ? other : name;
2205
2206        if (o->prefix_length)
2207                strip_prefix(o->prefix_length, &name, &other);
2208
2209        diff_fill_sha1_info(p->one);
2210        diff_fill_sha1_info(p->two);
2211
2212        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2213}
2214
2215void diff_setup(struct diff_options *options)
2216{
2217        memset(options, 0, sizeof(*options));
2218
2219        options->file = stdout;
2220
2221        options->line_termination = '\n';
2222        options->break_opt = -1;
2223        options->rename_limit = -1;
2224        options->dirstat_percent = 3;
2225        DIFF_OPT_CLR(options, DIRSTAT_CUMULATIVE);
2226        options->context = 3;
2227
2228        options->change = diff_change;
2229        options->add_remove = diff_addremove;
2230        if (diff_use_color_default > 0)
2231                DIFF_OPT_SET(options, COLOR_DIFF);
2232        else
2233                DIFF_OPT_CLR(options, COLOR_DIFF);
2234        options->detect_rename = diff_detect_rename_default;
2235
2236        if (!diff_mnemonic_prefix) {
2237                options->a_prefix = "a/";
2238                options->b_prefix = "b/";
2239        }
2240}
2241
2242int diff_setup_done(struct diff_options *options)
2243{
2244        int count = 0;
2245
2246        if (options->output_format & DIFF_FORMAT_NAME)
2247                count++;
2248        if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2249                count++;
2250        if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2251                count++;
2252        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2253                count++;
2254        if (count > 1)
2255                die("--name-only, --name-status, --check and -s are mutually exclusive");
2256
2257        if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2258                options->detect_rename = DIFF_DETECT_COPY;
2259
2260        if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2261                options->prefix = NULL;
2262        if (options->prefix)
2263                options->prefix_length = strlen(options->prefix);
2264        else
2265                options->prefix_length = 0;
2266
2267        if (options->output_format & (DIFF_FORMAT_NAME |
2268                                      DIFF_FORMAT_NAME_STATUS |
2269                                      DIFF_FORMAT_CHECKDIFF |
2270                                      DIFF_FORMAT_NO_OUTPUT))
2271                options->output_format &= ~(DIFF_FORMAT_RAW |
2272                                            DIFF_FORMAT_NUMSTAT |
2273                                            DIFF_FORMAT_DIFFSTAT |
2274                                            DIFF_FORMAT_SHORTSTAT |
2275                                            DIFF_FORMAT_DIRSTAT |
2276                                            DIFF_FORMAT_SUMMARY |
2277                                            DIFF_FORMAT_PATCH);
2278
2279        /*
2280         * These cases always need recursive; we do not drop caller-supplied
2281         * recursive bits for other formats here.
2282         */
2283        if (options->output_format & (DIFF_FORMAT_PATCH |
2284                                      DIFF_FORMAT_NUMSTAT |
2285                                      DIFF_FORMAT_DIFFSTAT |
2286                                      DIFF_FORMAT_SHORTSTAT |
2287                                      DIFF_FORMAT_DIRSTAT |
2288                                      DIFF_FORMAT_SUMMARY |
2289                                      DIFF_FORMAT_CHECKDIFF))
2290                DIFF_OPT_SET(options, RECURSIVE);
2291        /*
2292         * Also pickaxe would not work very well if you do not say recursive
2293         */
2294        if (options->pickaxe)
2295                DIFF_OPT_SET(options, RECURSIVE);
2296
2297        if (options->detect_rename && options->rename_limit < 0)
2298                options->rename_limit = diff_rename_limit_default;
2299        if (options->setup & DIFF_SETUP_USE_CACHE) {
2300                if (!active_cache)
2301                        /* read-cache does not die even when it fails
2302                         * so it is safe for us to do this here.  Also
2303                         * it does not smudge active_cache or active_nr
2304                         * when it fails, so we do not have to worry about
2305                         * cleaning it up ourselves either.
2306                         */
2307                        read_cache();
2308        }
2309        if (options->abbrev <= 0 || 40 < options->abbrev)
2310                options->abbrev = 40; /* full */
2311
2312        /*
2313         * It does not make sense to show the first hit we happened
2314         * to have found.  It does not make sense not to return with
2315         * exit code in such a case either.
2316         */
2317        if (DIFF_OPT_TST(options, QUIET)) {
2318                options->output_format = DIFF_FORMAT_NO_OUTPUT;
2319                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2320        }
2321
2322        return 0;
2323}
2324
2325static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2326{
2327        char c, *eq;
2328        int len;
2329
2330        if (*arg != '-')
2331                return 0;
2332        c = *++arg;
2333        if (!c)
2334                return 0;
2335        if (c == arg_short) {
2336                c = *++arg;
2337                if (!c)
2338                        return 1;
2339                if (val && isdigit(c)) {
2340                        char *end;
2341                        int n = strtoul(arg, &end, 10);
2342                        if (*end)
2343                                return 0;
2344                        *val = n;
2345                        return 1;
2346                }
2347                return 0;
2348        }
2349        if (c != '-')
2350                return 0;
2351        arg++;
2352        eq = strchr(arg, '=');
2353        if (eq)
2354                len = eq - arg;
2355        else
2356                len = strlen(arg);
2357        if (!len || strncmp(arg, arg_long, len))
2358                return 0;
2359        if (eq) {
2360                int n;
2361                char *end;
2362                if (!isdigit(*++eq))
2363                        return 0;
2364                n = strtoul(eq, &end, 10);
2365                if (*end)
2366                        return 0;
2367                *val = n;
2368        }
2369        return 1;
2370}
2371
2372static int diff_scoreopt_parse(const char *opt);
2373
2374int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2375{
2376        const char *arg = av[0];
2377
2378        /* Output format options */
2379        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2380                options->output_format |= DIFF_FORMAT_PATCH;
2381        else if (opt_arg(arg, 'U', "unified", &options->context))
2382                options->output_format |= DIFF_FORMAT_PATCH;
2383        else if (!strcmp(arg, "--raw"))
2384                options->output_format |= DIFF_FORMAT_RAW;
2385        else if (!strcmp(arg, "--patch-with-raw"))
2386                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2387        else if (!strcmp(arg, "--numstat"))
2388                options->output_format |= DIFF_FORMAT_NUMSTAT;
2389        else if (!strcmp(arg, "--shortstat"))
2390                options->output_format |= DIFF_FORMAT_SHORTSTAT;
2391        else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2392                options->output_format |= DIFF_FORMAT_DIRSTAT;
2393        else if (!strcmp(arg, "--cumulative")) {
2394                options->output_format |= DIFF_FORMAT_DIRSTAT;
2395                DIFF_OPT_SET(options, DIRSTAT_CUMULATIVE);
2396        } else if (opt_arg(arg, 0, "dirstat-by-file",
2397                           &options->dirstat_percent)) {
2398                options->output_format |= DIFF_FORMAT_DIRSTAT;
2399                DIFF_OPT_SET(options, DIRSTAT_BY_FILE);
2400        }
2401        else if (!strcmp(arg, "--check"))
2402                options->output_format |= DIFF_FORMAT_CHECKDIFF;
2403        else if (!strcmp(arg, "--summary"))
2404                options->output_format |= DIFF_FORMAT_SUMMARY;
2405        else if (!strcmp(arg, "--patch-with-stat"))
2406                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2407        else if (!strcmp(arg, "--name-only"))
2408                options->output_format |= DIFF_FORMAT_NAME;
2409        else if (!strcmp(arg, "--name-status"))
2410                options->output_format |= DIFF_FORMAT_NAME_STATUS;
2411        else if (!strcmp(arg, "-s"))
2412                options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2413        else if (!prefixcmp(arg, "--stat")) {
2414                char *end;
2415                int width = options->stat_width;
2416                int name_width = options->stat_name_width;
2417                arg += 6;
2418                end = (char *)arg;
2419
2420                switch (*arg) {
2421                case '-':
2422                        if (!prefixcmp(arg, "-width="))
2423                                width = strtoul(arg + 7, &end, 10);
2424                        else if (!prefixcmp(arg, "-name-width="))
2425                                name_width = strtoul(arg + 12, &end, 10);
2426                        break;
2427                case '=':
2428                        width = strtoul(arg+1, &end, 10);
2429                        if (*end == ',')
2430                                name_width = strtoul(end+1, &end, 10);
2431                }
2432
2433                /* Important! This checks all the error cases! */
2434                if (*end)
2435                        return 0;
2436                options->output_format |= DIFF_FORMAT_DIFFSTAT;
2437                options->stat_name_width = name_width;
2438                options->stat_width = width;
2439        }
2440
2441        /* renames options */
2442        else if (!prefixcmp(arg, "-B")) {
2443                if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2444                        return -1;
2445        }
2446        else if (!prefixcmp(arg, "-M")) {
2447                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2448                        return -1;
2449                options->detect_rename = DIFF_DETECT_RENAME;
2450        }
2451        else if (!prefixcmp(arg, "-C")) {
2452                if (options->detect_rename == DIFF_DETECT_COPY)
2453                        DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2454                if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2455                        return -1;
2456                options->detect_rename = DIFF_DETECT_COPY;
2457        }
2458        else if (!strcmp(arg, "--no-renames"))
2459                options->detect_rename = 0;
2460        else if (!strcmp(arg, "--relative"))
2461                DIFF_OPT_SET(options, RELATIVE_NAME);
2462        else if (!prefixcmp(arg, "--relative=")) {
2463                DIFF_OPT_SET(options, RELATIVE_NAME);
2464                options->prefix = arg + 11;
2465        }
2466
2467        /* xdiff options */
2468        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2469                options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2470        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2471                options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2472        else if (!strcmp(arg, "--ignore-space-at-eol"))
2473                options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2474
2475        /* flags options */
2476        else if (!strcmp(arg, "--binary")) {
2477                options->output_format |= DIFF_FORMAT_PATCH;
2478                DIFF_OPT_SET(options, BINARY);
2479        }
2480        else if (!strcmp(arg, "--full-index"))
2481                DIFF_OPT_SET(options, FULL_INDEX);
2482        else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2483                DIFF_OPT_SET(options, TEXT);
2484        else if (!strcmp(arg, "-R"))
2485                DIFF_OPT_SET(options, REVERSE_DIFF);
2486        else if (!strcmp(arg, "--find-copies-harder"))
2487                DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2488        else if (!strcmp(arg, "--follow"))
2489                DIFF_OPT_SET(options, FOLLOW_RENAMES);
2490        else if (!strcmp(arg, "--color"))
2491                DIFF_OPT_SET(options, COLOR_DIFF);
2492        else if (!strcmp(arg, "--no-color"))
2493                DIFF_OPT_CLR(options, COLOR_DIFF);
2494        else if (!strcmp(arg, "--color-words"))
2495                options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2496        else if (!strcmp(arg, "--exit-code"))
2497                DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2498        else if (!strcmp(arg, "--quiet"))
2499                DIFF_OPT_SET(options, QUIET);
2500        else if (!strcmp(arg, "--ext-diff"))
2501                DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2502        else if (!strcmp(arg, "--no-ext-diff"))
2503                DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2504        else if (!strcmp(arg, "--textconv"))
2505                DIFF_OPT_SET(options, ALLOW_TEXTCONV);
2506        else if (!strcmp(arg, "--no-textconv"))
2507                DIFF_OPT_CLR(options, ALLOW_TEXTCONV);
2508        else if (!strcmp(arg, "--ignore-submodules"))
2509                DIFF_OPT_SET(options, IGNORE_SUBMODULES);
2510
2511        /* misc options */
2512        else if (!strcmp(arg, "-z"))
2513                options->line_termination = 0;
2514        else if (!prefixcmp(arg, "-l"))
2515                options->rename_limit = strtoul(arg+2, NULL, 10);
2516        else if (!prefixcmp(arg, "-S"))
2517                options->pickaxe = arg + 2;
2518        else if (!strcmp(arg, "--pickaxe-all"))
2519                options->pickaxe_opts = DIFF_PICKAXE_ALL;
2520        else if (!strcmp(arg, "--pickaxe-regex"))
2521                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2522        else if (!prefixcmp(arg, "-O"))
2523                options->orderfile = arg + 2;
2524        else if (!prefixcmp(arg, "--diff-filter="))
2525                options->filter = arg + 14;
2526        else if (!strcmp(arg, "--abbrev"))
2527                options->abbrev = DEFAULT_ABBREV;
2528        else if (!prefixcmp(arg, "--abbrev=")) {
2529                options->abbrev = strtoul(arg + 9, NULL, 10);
2530                if (options->abbrev < MINIMUM_ABBREV)
2531                        options->abbrev = MINIMUM_ABBREV;
2532                else if (40 < options->abbrev)
2533                        options->abbrev = 40;
2534        }
2535        else if (!prefixcmp(arg, "--src-prefix="))
2536                options->a_prefix = arg + 13;
2537        else if (!prefixcmp(arg, "--dst-prefix="))
2538                options->b_prefix = arg + 13;
2539        else if (!strcmp(arg, "--no-prefix"))
2540                options->a_prefix = options->b_prefix = "";
2541        else if (!prefixcmp(arg, "--output=")) {
2542                options->file = fopen(arg + strlen("--output="), "w");
2543                options->close_file = 1;
2544        } else
2545                return 0;
2546        return 1;
2547}
2548
2549static int parse_num(const char **cp_p)
2550{
2551        unsigned long num, scale;
2552        int ch, dot;
2553        const char *cp = *cp_p;
2554
2555        num = 0;
2556        scale = 1;
2557        dot = 0;
2558        for(;;) {
2559                ch = *cp;
2560                if ( !dot && ch == '.' ) {
2561                        scale = 1;
2562                        dot = 1;
2563                } else if ( ch == '%' ) {
2564                        scale = dot ? scale*100 : 100;
2565                        cp++;   /* % is always at the end */
2566                        break;
2567                } else if ( ch >= '0' && ch <= '9' ) {
2568                        if ( scale < 100000 ) {
2569                                scale *= 10;
2570                                num = (num*10) + (ch-'0');
2571                        }
2572                } else {
2573                        break;
2574                }
2575                cp++;
2576        }
2577        *cp_p = cp;
2578
2579        /* user says num divided by scale and we say internally that
2580         * is MAX_SCORE * num / scale.
2581         */
2582        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2583}
2584
2585static int diff_scoreopt_parse(const char *opt)
2586{
2587        int opt1, opt2, cmd;
2588
2589        if (*opt++ != '-')
2590                return -1;
2591        cmd = *opt++;
2592        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2593                return -1; /* that is not a -M, -C nor -B option */
2594
2595        opt1 = parse_num(&opt);
2596        if (cmd != 'B')
2597                opt2 = 0;
2598        else {
2599                if (*opt == 0)
2600                        opt2 = 0;
2601                else if (*opt != '/')
2602                        return -1; /* we expect -B80/99 or -B80 */
2603                else {
2604                        opt++;
2605                        opt2 = parse_num(&opt);
2606                }
2607        }
2608        if (*opt != 0)
2609                return -1;
2610        return opt1 | (opt2 << 16);
2611}
2612
2613struct diff_queue_struct diff_queued_diff;
2614
2615void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2616{
2617        if (queue->alloc <= queue->nr) {
2618                queue->alloc = alloc_nr(queue->alloc);
2619                queue->queue = xrealloc(queue->queue,
2620                                        sizeof(dp) * queue->alloc);
2621        }
2622        queue->queue[queue->nr++] = dp;
2623}
2624
2625struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2626                                 struct diff_filespec *one,
2627                                 struct diff_filespec *two)
2628{
2629        struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2630        dp->one = one;
2631        dp->two = two;
2632        if (queue)
2633                diff_q(queue, dp);
2634        return dp;
2635}
2636
2637void diff_free_filepair(struct diff_filepair *p)
2638{
2639        free_filespec(p->one);
2640        free_filespec(p->two);
2641        free(p);
2642}
2643
2644/* This is different from find_unique_abbrev() in that
2645 * it stuffs the result with dots for alignment.
2646 */
2647const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2648{
2649        int abblen;
2650        const char *abbrev;
2651        if (len == 40)
2652                return sha1_to_hex(sha1);
2653
2654        abbrev = find_unique_abbrev(sha1, len);
2655        abblen = strlen(abbrev);
2656        if (abblen < 37) {
2657                static char hex[41];
2658                if (len < abblen && abblen <= len + 2)
2659                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2660                else
2661                        sprintf(hex, "%s...", abbrev);
2662                return hex;
2663        }
2664        return sha1_to_hex(sha1);
2665}
2666
2667static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2668{
2669        int line_termination = opt->line_termination;
2670        int inter_name_termination = line_termination ? '\t' : '\0';
2671
2672        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2673                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2674                        diff_unique_abbrev(p->one->sha1, opt->abbrev));
2675                fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2676        }
2677        if (p->score) {
2678                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2679                        inter_name_termination);
2680        } else {
2681                fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2682        }
2683
2684        if (p->status == DIFF_STATUS_COPIED ||
2685            p->status == DIFF_STATUS_RENAMED) {
2686                const char *name_a, *name_b;
2687                name_a = p->one->path;
2688                name_b = p->two->path;
2689                strip_prefix(opt->prefix_length, &name_a, &name_b);
2690                write_name_quoted(name_a, opt->file, inter_name_termination);
2691                write_name_quoted(name_b, opt->file, line_termination);
2692        } else {
2693                const char *name_a, *name_b;
2694                name_a = p->one->mode ? p->one->path : p->two->path;
2695                name_b = NULL;
2696                strip_prefix(opt->prefix_length, &name_a, &name_b);
2697                write_name_quoted(name_a, opt->file, line_termination);
2698        }
2699}
2700
2701int diff_unmodified_pair(struct diff_filepair *p)
2702{
2703        /* This function is written stricter than necessary to support
2704         * the currently implemented transformers, but the idea is to
2705         * let transformers to produce diff_filepairs any way they want,
2706         * and filter and clean them up here before producing the output.
2707         */
2708        struct diff_filespec *one = p->one, *two = p->two;
2709
2710        if (DIFF_PAIR_UNMERGED(p))
2711                return 0; /* unmerged is interesting */
2712
2713        /* deletion, addition, mode or type change
2714         * and rename are all interesting.
2715         */
2716        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2717            DIFF_PAIR_MODE_CHANGED(p) ||
2718            strcmp(one->path, two->path))
2719                return 0;
2720
2721        /* both are valid and point at the same path.  that is, we are
2722         * dealing with a change.
2723         */
2724        if (one->sha1_valid && two->sha1_valid &&
2725            !hashcmp(one->sha1, two->sha1))
2726                return 1; /* no change */
2727        if (!one->sha1_valid && !two->sha1_valid)
2728                return 1; /* both look at the same file on the filesystem. */
2729        return 0;
2730}
2731
2732static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2733{
2734        if (diff_unmodified_pair(p))
2735                return;
2736
2737        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2738            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2739                return; /* no tree diffs in patch format */
2740
2741        run_diff(p, o);
2742}
2743
2744static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2745                            struct diffstat_t *diffstat)
2746{
2747        if (diff_unmodified_pair(p))
2748                return;
2749
2750        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2751            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2752                return; /* no tree diffs in patch format */
2753
2754        run_diffstat(p, o, diffstat);
2755}
2756
2757static void diff_flush_checkdiff(struct diff_filepair *p,
2758                struct diff_options *o)
2759{
2760        if (diff_unmodified_pair(p))
2761                return;
2762
2763        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2764            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2765                return; /* no tree diffs in patch format */
2766
2767        run_checkdiff(p, o);
2768}
2769
2770int diff_queue_is_empty(void)
2771{
2772        struct diff_queue_struct *q = &diff_queued_diff;
2773        int i;
2774        for (i = 0; i < q->nr; i++)
2775                if (!diff_unmodified_pair(q->queue[i]))
2776                        return 0;
2777        return 1;
2778}
2779
2780#if DIFF_DEBUG
2781void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2782{
2783        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2784                x, one ? one : "",
2785                s->path,
2786                DIFF_FILE_VALID(s) ? "valid" : "invalid",
2787                s->mode,
2788                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2789        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2790                x, one ? one : "",
2791                s->size, s->xfrm_flags);
2792}
2793
2794void diff_debug_filepair(const struct diff_filepair *p, int i)
2795{
2796        diff_debug_filespec(p->one, i, "one");
2797        diff_debug_filespec(p->two, i, "two");
2798        fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2799                p->score, p->status ? p->status : '?',
2800                p->one->rename_used, p->broken_pair);
2801}
2802
2803void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2804{
2805        int i;
2806        if (msg)
2807                fprintf(stderr, "%s\n", msg);
2808        fprintf(stderr, "q->nr = %d\n", q->nr);
2809        for (i = 0; i < q->nr; i++) {
2810                struct diff_filepair *p = q->queue[i];
2811                diff_debug_filepair(p, i);
2812        }
2813}
2814#endif
2815
2816static void diff_resolve_rename_copy(void)
2817{
2818        int i;
2819        struct diff_filepair *p;
2820        struct diff_queue_struct *q = &diff_queued_diff;
2821
2822        diff_debug_queue("resolve-rename-copy", q);
2823
2824        for (i = 0; i < q->nr; i++) {
2825                p = q->queue[i];
2826                p->status = 0; /* undecided */
2827                if (DIFF_PAIR_UNMERGED(p))
2828                        p->status = DIFF_STATUS_UNMERGED;
2829                else if (!DIFF_FILE_VALID(p->one))
2830                        p->status = DIFF_STATUS_ADDED;
2831                else if (!DIFF_FILE_VALID(p->two))
2832                        p->status = DIFF_STATUS_DELETED;
2833                else if (DIFF_PAIR_TYPE_CHANGED(p))
2834                        p->status = DIFF_STATUS_TYPE_CHANGED;
2835
2836                /* from this point on, we are dealing with a pair
2837                 * whose both sides are valid and of the same type, i.e.
2838                 * either in-place edit or rename/copy edit.
2839                 */
2840                else if (DIFF_PAIR_RENAME(p)) {
2841                        /*
2842                         * A rename might have re-connected a broken
2843                         * pair up, causing the pathnames to be the
2844                         * same again. If so, that's not a rename at
2845                         * all, just a modification..
2846                         *
2847                         * Otherwise, see if this source was used for
2848                         * multiple renames, in which case we decrement
2849                         * the count, and call it a copy.
2850                         */
2851                        if (!strcmp(p->one->path, p->two->path))
2852                                p->status = DIFF_STATUS_MODIFIED;
2853                        else if (--p->one->rename_used > 0)
2854                                p->status = DIFF_STATUS_COPIED;
2855                        else
2856                                p->status = DIFF_STATUS_RENAMED;
2857                }
2858                else if (hashcmp(p->one->sha1, p->two->sha1) ||
2859                         p->one->mode != p->two->mode ||
2860                         is_null_sha1(p->one->sha1))
2861                        p->status = DIFF_STATUS_MODIFIED;
2862                else {
2863                        /* This is a "no-change" entry and should not
2864                         * happen anymore, but prepare for broken callers.
2865                         */
2866                        error("feeding unmodified %s to diffcore",
2867                              p->one->path);
2868                        p->status = DIFF_STATUS_UNKNOWN;
2869                }
2870        }
2871        diff_debug_queue("resolve-rename-copy done", q);
2872}
2873
2874static int check_pair_status(struct diff_filepair *p)
2875{
2876        switch (p->status) {
2877        case DIFF_STATUS_UNKNOWN:
2878                return 0;
2879        case 0:
2880                die("internal error in diff-resolve-rename-copy");
2881        default:
2882                return 1;
2883        }
2884}
2885
2886static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2887{
2888        int fmt = opt->output_format;
2889
2890        if (fmt & DIFF_FORMAT_CHECKDIFF)
2891                diff_flush_checkdiff(p, opt);
2892        else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2893                diff_flush_raw(p, opt);
2894        else if (fmt & DIFF_FORMAT_NAME) {
2895                const char *name_a, *name_b;
2896                name_a = p->two->path;
2897                name_b = NULL;
2898                strip_prefix(opt->prefix_length, &name_a, &name_b);
2899                write_name_quoted(name_a, opt->file, opt->line_termination);
2900        }
2901}
2902
2903static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
2904{
2905        if (fs->mode)
2906                fprintf(file, " %s mode %06o ", newdelete, fs->mode);
2907        else
2908                fprintf(file, " %s ", newdelete);
2909        write_name_quoted(fs->path, file, '\n');
2910}
2911
2912
2913static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
2914{
2915        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2916                fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
2917                        show_name ? ' ' : '\n');
2918                if (show_name) {
2919                        write_name_quoted(p->two->path, file, '\n');
2920                }
2921        }
2922}
2923
2924static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
2925{
2926        char *names = pprint_rename(p->one->path, p->two->path);
2927
2928        fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
2929        free(names);
2930        show_mode_change(file, p, 0);
2931}
2932
2933static void diff_summary(FILE *file, struct diff_filepair *p)
2934{
2935        switch(p->status) {
2936        case DIFF_STATUS_DELETED:
2937                show_file_mode_name(file, "delete", p->one);
2938                break;
2939        case DIFF_STATUS_ADDED:
2940                show_file_mode_name(file, "create", p->two);
2941                break;
2942        case DIFF_STATUS_COPIED:
2943                show_rename_copy(file, "copy", p);
2944                break;
2945        case DIFF_STATUS_RENAMED:
2946                show_rename_copy(file, "rename", p);
2947                break;
2948        default:
2949                if (p->score) {
2950                        fputs(" rewrite ", file);
2951                        write_name_quoted(p->two->path, file, ' ');
2952                        fprintf(file, "(%d%%)\n", similarity_index(p));
2953                }
2954                show_mode_change(file, p, !p->score);
2955                break;
2956        }
2957}
2958
2959struct patch_id_t {
2960        git_SHA_CTX *ctx;
2961        int patchlen;
2962};
2963
2964static int remove_space(char *line, int len)
2965{
2966        int i;
2967        char *dst = line;
2968        unsigned char c;
2969
2970        for (i = 0; i < len; i++)
2971                if (!isspace((c = line[i])))
2972                        *dst++ = c;
2973
2974        return dst - line;
2975}
2976
2977static void patch_id_consume(void *priv, char *line, unsigned long len)
2978{
2979        struct patch_id_t *data = priv;
2980        int new_len;
2981
2982        /* Ignore line numbers when computing the SHA1 of the patch */
2983        if (!prefixcmp(line, "@@ -"))
2984                return;
2985
2986        new_len = remove_space(line, len);
2987
2988        git_SHA1_Update(data->ctx, line, new_len);
2989        data->patchlen += new_len;
2990}
2991
2992/* returns 0 upon success, and writes result into sha1 */
2993static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2994{
2995        struct diff_queue_struct *q = &diff_queued_diff;
2996        int i;
2997        git_SHA_CTX ctx;
2998        struct patch_id_t data;
2999        char buffer[PATH_MAX * 4 + 20];
3000
3001        git_SHA1_Init(&ctx);
3002        memset(&data, 0, sizeof(struct patch_id_t));
3003        data.ctx = &ctx;
3004
3005        for (i = 0; i < q->nr; i++) {
3006                xpparam_t xpp;
3007                xdemitconf_t xecfg;
3008                xdemitcb_t ecb;
3009                mmfile_t mf1, mf2;
3010                struct diff_filepair *p = q->queue[i];
3011                int len1, len2;
3012
3013                memset(&xpp, 0, sizeof(xpp));
3014                memset(&xecfg, 0, sizeof(xecfg));
3015                if (p->status == 0)
3016                        return error("internal diff status error");
3017                if (p->status == DIFF_STATUS_UNKNOWN)
3018                        continue;
3019                if (diff_unmodified_pair(p))
3020                        continue;
3021                if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
3022                    (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
3023                        continue;
3024                if (DIFF_PAIR_UNMERGED(p))
3025                        continue;
3026
3027                diff_fill_sha1_info(p->one);
3028                diff_fill_sha1_info(p->two);
3029                if (fill_mmfile(&mf1, p->one) < 0 ||
3030                                fill_mmfile(&mf2, p->two) < 0)
3031                        return error("unable to read files to diff");
3032
3033                len1 = remove_space(p->one->path, strlen(p->one->path));
3034                len2 = remove_space(p->two->path, strlen(p->two->path));
3035                if (p->one->mode == 0)
3036                        len1 = snprintf(buffer, sizeof(buffer),
3037                                        "diff--gita/%.*sb/%.*s"
3038                                        "newfilemode%06o"
3039                                        "---/dev/null"
3040                                        "+++b/%.*s",
3041                                        len1, p->one->path,
3042                                        len2, p->two->path,
3043                                        p->two->mode,
3044                                        len2, p->two->path);
3045                else if (p->two->mode == 0)
3046                        len1 = snprintf(buffer, sizeof(buffer),
3047                                        "diff--gita/%.*sb/%.*s"
3048                                        "deletedfilemode%06o"
3049                                        "---a/%.*s"
3050                                        "+++/dev/null",
3051                                        len1, p->one->path,
3052                                        len2, p->two->path,
3053                                        p->one->mode,
3054                                        len1, p->one->path);
3055                else
3056                        len1 = snprintf(buffer, sizeof(buffer),
3057                                        "diff--gita/%.*sb/%.*s"
3058                                        "---a/%.*s"
3059                                        "+++b/%.*s",
3060                                        len1, p->one->path,
3061                                        len2, p->two->path,
3062                                        len1, p->one->path,
3063                                        len2, p->two->path);
3064                git_SHA1_Update(&ctx, buffer, len1);
3065
3066                xpp.flags = XDF_NEED_MINIMAL;
3067                xecfg.ctxlen = 3;
3068                xecfg.flags = XDL_EMIT_FUNCNAMES;
3069                xdi_diff_outf(&mf1, &mf2, patch_id_consume, &data,
3070                              &xpp, &xecfg, &ecb);
3071        }
3072
3073        git_SHA1_Final(sha1, &ctx);
3074        return 0;
3075}
3076
3077int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3078{
3079        struct diff_queue_struct *q = &diff_queued_diff;
3080        int i;
3081        int result = diff_get_patch_id(options, sha1);
3082
3083        for (i = 0; i < q->nr; i++)
3084                diff_free_filepair(q->queue[i]);
3085
3086        free(q->queue);
3087        q->queue = NULL;
3088        q->nr = q->alloc = 0;
3089
3090        return result;
3091}
3092
3093static int is_summary_empty(const struct diff_queue_struct *q)
3094{
3095        int i;
3096
3097        for (i = 0; i < q->nr; i++) {
3098                const struct diff_filepair *p = q->queue[i];
3099
3100                switch (p->status) {
3101                case DIFF_STATUS_DELETED:
3102                case DIFF_STATUS_ADDED:
3103                case DIFF_STATUS_COPIED:
3104                case DIFF_STATUS_RENAMED:
3105                        return 0;
3106                default:
3107                        if (p->score)
3108                                return 0;
3109                        if (p->one->mode && p->two->mode &&
3110                            p->one->mode != p->two->mode)
3111                                return 0;
3112                        break;
3113                }
3114        }
3115        return 1;
3116}
3117
3118void diff_flush(struct diff_options *options)
3119{
3120        struct diff_queue_struct *q = &diff_queued_diff;
3121        int i, output_format = options->output_format;
3122        int separator = 0;
3123
3124        /*
3125         * Order: raw, stat, summary, patch
3126         * or:    name/name-status/checkdiff (other bits clear)
3127         */
3128        if (!q->nr)
3129                goto free_queue;
3130
3131        if (output_format & (DIFF_FORMAT_RAW |
3132                             DIFF_FORMAT_NAME |
3133                             DIFF_FORMAT_NAME_STATUS |
3134                             DIFF_FORMAT_CHECKDIFF)) {
3135                for (i = 0; i < q->nr; i++) {
3136                        struct diff_filepair *p = q->queue[i];
3137                        if (check_pair_status(p))
3138                                flush_one_pair(p, options);
3139                }
3140                separator++;
3141        }
3142
3143        if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT)) {
3144                struct diffstat_t diffstat;
3145
3146                memset(&diffstat, 0, sizeof(struct diffstat_t));
3147                for (i = 0; i < q->nr; i++) {
3148                        struct diff_filepair *p = q->queue[i];
3149                        if (check_pair_status(p))
3150                                diff_flush_stat(p, options, &diffstat);
3151                }
3152                if (output_format & DIFF_FORMAT_NUMSTAT)
3153                        show_numstat(&diffstat, options);
3154                if (output_format & DIFF_FORMAT_DIFFSTAT)
3155                        show_stats(&diffstat, options);
3156                if (output_format & DIFF_FORMAT_SHORTSTAT)
3157                        show_shortstats(&diffstat, options);
3158                free_diffstat_info(&diffstat);
3159                separator++;
3160        }
3161        if (output_format & DIFF_FORMAT_DIRSTAT)
3162                show_dirstat(options);
3163
3164        if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3165                for (i = 0; i < q->nr; i++)
3166                        diff_summary(options->file, q->queue[i]);
3167                separator++;
3168        }
3169
3170        if (output_format & DIFF_FORMAT_PATCH) {
3171                if (separator) {
3172                        putc(options->line_termination, options->file);
3173                        if (options->stat_sep) {
3174                                /* attach patch instead of inline */
3175                                fputs(options->stat_sep, options->file);
3176                        }
3177                }
3178
3179                for (i = 0; i < q->nr; i++) {
3180                        struct diff_filepair *p = q->queue[i];
3181                        if (check_pair_status(p))
3182                                diff_flush_patch(p, options);
3183                }
3184        }
3185
3186        if (output_format & DIFF_FORMAT_CALLBACK)
3187                options->format_callback(q, options, options->format_callback_data);
3188
3189        for (i = 0; i < q->nr; i++)
3190                diff_free_filepair(q->queue[i]);
3191free_queue:
3192        free(q->queue);
3193        q->queue = NULL;
3194        q->nr = q->alloc = 0;
3195        if (options->close_file)
3196                fclose(options->file);
3197}
3198
3199static void diffcore_apply_filter(const char *filter)
3200{
3201        int i;
3202        struct diff_queue_struct *q = &diff_queued_diff;
3203        struct diff_queue_struct outq;
3204        outq.queue = NULL;
3205        outq.nr = outq.alloc = 0;
3206
3207        if (!filter)
3208                return;
3209
3210        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3211                int found;
3212                for (i = found = 0; !found && i < q->nr; i++) {
3213                        struct diff_filepair *p = q->queue[i];
3214                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3215                             ((p->score &&
3216                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3217                              (!p->score &&
3218                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3219                            ((p->status != DIFF_STATUS_MODIFIED) &&
3220                             strchr(filter, p->status)))
3221                                found++;
3222                }
3223                if (found)
3224                        return;
3225
3226                /* otherwise we will clear the whole queue
3227                 * by copying the empty outq at the end of this
3228                 * function, but first clear the current entries
3229                 * in the queue.
3230                 */
3231                for (i = 0; i < q->nr; i++)
3232                        diff_free_filepair(q->queue[i]);
3233        }
3234        else {
3235                /* Only the matching ones */
3236                for (i = 0; i < q->nr; i++) {
3237                        struct diff_filepair *p = q->queue[i];
3238
3239                        if (((p->status == DIFF_STATUS_MODIFIED) &&
3240                             ((p->score &&
3241                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3242                              (!p->score &&
3243                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3244                            ((p->status != DIFF_STATUS_MODIFIED) &&
3245                             strchr(filter, p->status)))
3246                                diff_q(&outq, p);
3247                        else
3248                                diff_free_filepair(p);
3249                }
3250        }
3251        free(q->queue);
3252        *q = outq;
3253}
3254
3255/* Check whether two filespecs with the same mode and size are identical */
3256static int diff_filespec_is_identical(struct diff_filespec *one,
3257                                      struct diff_filespec *two)
3258{
3259        if (S_ISGITLINK(one->mode))
3260                return 0;
3261        if (diff_populate_filespec(one, 0))
3262                return 0;
3263        if (diff_populate_filespec(two, 0))
3264                return 0;
3265        return !memcmp(one->data, two->data, one->size);
3266}
3267
3268static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3269{
3270        int i;
3271        struct diff_queue_struct *q = &diff_queued_diff;
3272        struct diff_queue_struct outq;
3273        outq.queue = NULL;
3274        outq.nr = outq.alloc = 0;
3275
3276        for (i = 0; i < q->nr; i++) {
3277                struct diff_filepair *p = q->queue[i];
3278
3279                /*
3280                 * 1. Entries that come from stat info dirtyness
3281                 *    always have both sides (iow, not create/delete),
3282                 *    one side of the object name is unknown, with
3283                 *    the same mode and size.  Keep the ones that
3284                 *    do not match these criteria.  They have real
3285                 *    differences.
3286                 *
3287                 * 2. At this point, the file is known to be modified,
3288                 *    with the same mode and size, and the object
3289                 *    name of one side is unknown.  Need to inspect
3290                 *    the identical contents.
3291                 */
3292                if (!DIFF_FILE_VALID(p->one) || /* (1) */
3293                    !DIFF_FILE_VALID(p->two) ||
3294                    (p->one->sha1_valid && p->two->sha1_valid) ||
3295                    (p->one->mode != p->two->mode) ||
3296                    diff_populate_filespec(p->one, 1) ||
3297                    diff_populate_filespec(p->two, 1) ||
3298                    (p->one->size != p->two->size) ||
3299                    !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3300                        diff_q(&outq, p);
3301                else {
3302                        /*
3303                         * The caller can subtract 1 from skip_stat_unmatch
3304                         * to determine how many paths were dirty only
3305                         * due to stat info mismatch.
3306                         */
3307                        if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3308                                diffopt->skip_stat_unmatch++;
3309                        diff_free_filepair(p);
3310                }
3311        }
3312        free(q->queue);
3313        *q = outq;
3314}
3315
3316void diffcore_std(struct diff_options *options)
3317{
3318        if (options->skip_stat_unmatch)
3319                diffcore_skip_stat_unmatch(options);
3320        if (options->break_opt != -1)
3321                diffcore_break(options->break_opt);
3322        if (options->detect_rename)
3323                diffcore_rename(options);
3324        if (options->break_opt != -1)
3325                diffcore_merge_broken();
3326        if (options->pickaxe)
3327                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3328        if (options->orderfile)
3329                diffcore_order(options->orderfile);
3330        diff_resolve_rename_copy();
3331        diffcore_apply_filter(options->filter);
3332
3333        if (diff_queued_diff.nr)
3334                DIFF_OPT_SET(options, HAS_CHANGES);
3335        else
3336                DIFF_OPT_CLR(options, HAS_CHANGES);
3337}
3338
3339int diff_result_code(struct diff_options *opt, int status)
3340{
3341        int result = 0;
3342        if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3343            !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3344                return status;
3345        if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3346            DIFF_OPT_TST(opt, HAS_CHANGES))
3347                result |= 01;
3348        if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3349            DIFF_OPT_TST(opt, CHECK_FAILED))
3350                result |= 02;
3351        return result;
3352}
3353
3354void diff_addremove(struct diff_options *options,
3355                    int addremove, unsigned mode,
3356                    const unsigned char *sha1,
3357                    const char *concatpath)
3358{
3359        struct diff_filespec *one, *two;
3360
3361        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(mode))
3362                return;
3363
3364        /* This may look odd, but it is a preparation for
3365         * feeding "there are unchanged files which should
3366         * not produce diffs, but when you are doing copy
3367         * detection you would need them, so here they are"
3368         * entries to the diff-core.  They will be prefixed
3369         * with something like '=' or '*' (I haven't decided
3370         * which but should not make any difference).
3371         * Feeding the same new and old to diff_change()
3372         * also has the same effect.
3373         * Before the final output happens, they are pruned after
3374         * merged into rename/copy pairs as appropriate.
3375         */
3376        if (DIFF_OPT_TST(options, REVERSE_DIFF))
3377                addremove = (addremove == '+' ? '-' :
3378                             addremove == '-' ? '+' : addremove);
3379
3380        if (options->prefix &&
3381            strncmp(concatpath, options->prefix, options->prefix_length))
3382                return;
3383
3384        one = alloc_filespec(concatpath);
3385        two = alloc_filespec(concatpath);
3386
3387        if (addremove != '+')
3388                fill_filespec(one, sha1, mode);
3389        if (addremove != '-')
3390                fill_filespec(two, sha1, mode);
3391
3392        diff_queue(&diff_queued_diff, one, two);
3393        DIFF_OPT_SET(options, HAS_CHANGES);
3394}
3395
3396void diff_change(struct diff_options *options,
3397                 unsigned old_mode, unsigned new_mode,
3398                 const unsigned char *old_sha1,
3399                 const unsigned char *new_sha1,
3400                 const char *concatpath)
3401{
3402        struct diff_filespec *one, *two;
3403
3404        if (DIFF_OPT_TST(options, IGNORE_SUBMODULES) && S_ISGITLINK(old_mode)
3405                        && S_ISGITLINK(new_mode))
3406                return;
3407
3408        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3409                unsigned tmp;
3410                const unsigned char *tmp_c;
3411                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3412                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3413        }
3414
3415        if (options->prefix &&
3416            strncmp(concatpath, options->prefix, options->prefix_length))
3417                return;
3418
3419        one = alloc_filespec(concatpath);
3420        two = alloc_filespec(concatpath);
3421        fill_filespec(one, old_sha1, old_mode);
3422        fill_filespec(two, new_sha1, new_mode);
3423
3424        diff_queue(&diff_queued_diff, one, two);
3425        DIFF_OPT_SET(options, HAS_CHANGES);
3426}
3427
3428void diff_unmerge(struct diff_options *options,
3429                  const char *path,
3430                  unsigned mode, const unsigned char *sha1)
3431{
3432        struct diff_filespec *one, *two;
3433
3434        if (options->prefix &&
3435            strncmp(path, options->prefix, options->prefix_length))
3436                return;
3437
3438        one = alloc_filespec(path);
3439        two = alloc_filespec(path);
3440        fill_filespec(one, sha1, mode);
3441        diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3442}
3443
3444static char *run_textconv(const char *pgm, struct diff_filespec *spec,
3445                size_t *outsize)
3446{
3447        struct diff_tempfile temp;
3448        const char *argv[3];
3449        const char **arg = argv;
3450        struct child_process child;
3451        struct strbuf buf = STRBUF_INIT;
3452
3453        prepare_temp_file(spec->path, &temp, spec);
3454        *arg++ = pgm;
3455        *arg++ = temp.name;
3456        *arg = NULL;
3457
3458        memset(&child, 0, sizeof(child));
3459        child.argv = argv;
3460        child.out = -1;
3461        if (start_command(&child) != 0 ||
3462            strbuf_read(&buf, child.out, 0) < 0 ||
3463            finish_command(&child) != 0) {
3464                if (temp.name == temp.tmp_path)
3465                        unlink(temp.name);
3466                error("error running textconv command '%s'", pgm);
3467                return NULL;
3468        }
3469        if (temp.name == temp.tmp_path)
3470                unlink(temp.name);
3471
3472        return strbuf_detach(&buf, outsize);
3473}