diff.con commit send-email: quiet some warnings, reject invalid addresses (db3106b)
   1/*
   2 * Copyright (C) 2005 Junio C Hamano
   3 */
   4#include <sys/types.h>
   5#include <sys/wait.h>
   6#include <signal.h>
   7#include "cache.h"
   8#include "quote.h"
   9#include "diff.h"
  10#include "diffcore.h"
  11#include "delta.h"
  12#include "xdiff-interface.h"
  13
  14static int use_size_cache;
  15
  16int diff_rename_limit_default = -1;
  17
  18int git_diff_config(const char *var, const char *value)
  19{
  20        if (!strcmp(var, "diff.renamelimit")) {
  21                diff_rename_limit_default = git_config_int(var, value);
  22                return 0;
  23        }
  24
  25        return git_default_config(var, value);
  26}
  27
  28static char *quote_one(const char *str)
  29{
  30        int needlen;
  31        char *xp;
  32
  33        if (!str)
  34                return NULL;
  35        needlen = quote_c_style(str, NULL, NULL, 0);
  36        if (!needlen)
  37                return strdup(str);
  38        xp = xmalloc(needlen + 1);
  39        quote_c_style(str, xp, NULL, 0);
  40        return xp;
  41}
  42
  43static char *quote_two(const char *one, const char *two)
  44{
  45        int need_one = quote_c_style(one, NULL, NULL, 1);
  46        int need_two = quote_c_style(two, NULL, NULL, 1);
  47        char *xp;
  48
  49        if (need_one + need_two) {
  50                if (!need_one) need_one = strlen(one);
  51                if (!need_two) need_one = strlen(two);
  52
  53                xp = xmalloc(need_one + need_two + 3);
  54                xp[0] = '"';
  55                quote_c_style(one, xp + 1, NULL, 1);
  56                quote_c_style(two, xp + need_one + 1, NULL, 1);
  57                strcpy(xp + need_one + need_two + 1, "\"");
  58                return xp;
  59        }
  60        need_one = strlen(one);
  61        need_two = strlen(two);
  62        xp = xmalloc(need_one + need_two + 1);
  63        strcpy(xp, one);
  64        strcpy(xp + need_one, two);
  65        return xp;
  66}
  67
  68static const char *external_diff(void)
  69{
  70        static const char *external_diff_cmd = NULL;
  71        static int done_preparing = 0;
  72
  73        if (done_preparing)
  74                return external_diff_cmd;
  75        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
  76        done_preparing = 1;
  77        return external_diff_cmd;
  78}
  79
  80#define TEMPFILE_PATH_LEN               50
  81
  82static struct diff_tempfile {
  83        const char *name; /* filename external diff should read from */
  84        char hex[41];
  85        char mode[10];
  86        char tmp_path[TEMPFILE_PATH_LEN];
  87} diff_temp[2];
  88
  89static int count_lines(const char *data, int size)
  90{
  91        int count, ch, completely_empty = 1, nl_just_seen = 0;
  92        count = 0;
  93        while (0 < size--) {
  94                ch = *data++;
  95                if (ch == '\n') {
  96                        count++;
  97                        nl_just_seen = 1;
  98                        completely_empty = 0;
  99                }
 100                else {
 101                        nl_just_seen = 0;
 102                        completely_empty = 0;
 103                }
 104        }
 105        if (completely_empty)
 106                return 0;
 107        if (!nl_just_seen)
 108                count++; /* no trailing newline */
 109        return count;
 110}
 111
 112static void print_line_count(int count)
 113{
 114        switch (count) {
 115        case 0:
 116                printf("0,0");
 117                break;
 118        case 1:
 119                printf("1");
 120                break;
 121        default:
 122                printf("1,%d", count);
 123                break;
 124        }
 125}
 126
 127static void copy_file(int prefix, const char *data, int size)
 128{
 129        int ch, nl_just_seen = 1;
 130        while (0 < size--) {
 131                ch = *data++;
 132                if (nl_just_seen)
 133                        putchar(prefix);
 134                putchar(ch);
 135                if (ch == '\n')
 136                        nl_just_seen = 1;
 137                else
 138                        nl_just_seen = 0;
 139        }
 140        if (!nl_just_seen)
 141                printf("\n\\ No newline at end of file\n");
 142}
 143
 144static void emit_rewrite_diff(const char *name_a,
 145                              const char *name_b,
 146                              struct diff_filespec *one,
 147                              struct diff_filespec *two)
 148{
 149        int lc_a, lc_b;
 150        diff_populate_filespec(one, 0);
 151        diff_populate_filespec(two, 0);
 152        lc_a = count_lines(one->data, one->size);
 153        lc_b = count_lines(two->data, two->size);
 154        printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
 155        print_line_count(lc_a);
 156        printf(" +");
 157        print_line_count(lc_b);
 158        printf(" @@\n");
 159        if (lc_a)
 160                copy_file('-', one->data, one->size);
 161        if (lc_b)
 162                copy_file('+', two->data, two->size);
 163}
 164
 165static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 166{
 167        if (!DIFF_FILE_VALID(one)) {
 168                mf->ptr = ""; /* does not matter */
 169                mf->size = 0;
 170                return 0;
 171        }
 172        else if (diff_populate_filespec(one, 0))
 173                return -1;
 174        mf->ptr = one->data;
 175        mf->size = one->size;
 176        return 0;
 177}
 178
 179struct emit_callback {
 180        const char **label_path;
 181};
 182
 183static int fn_out(void *priv, mmbuffer_t *mb, int nbuf)
 184{
 185        int i;
 186        struct emit_callback *ecbdata = priv;
 187
 188        if (ecbdata->label_path[0]) {
 189                printf("--- %s\n", ecbdata->label_path[0]);
 190                printf("+++ %s\n", ecbdata->label_path[1]);
 191                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 192        }
 193        for (i = 0; i < nbuf; i++)
 194                if (!fwrite(mb[i].ptr, mb[i].size, 1, stdout))
 195                        return -1;
 196        return 0;
 197}
 198
 199static char *pprint_rename(const char *a, const char *b)
 200{
 201        const char *old = a;
 202        const char *new = b;
 203        char *name = NULL;
 204        int pfx_length, sfx_length;
 205        int len_a = strlen(a);
 206        int len_b = strlen(b);
 207
 208        /* Find common prefix */
 209        pfx_length = 0;
 210        while (*old && *new && *old == *new) {
 211                if (*old == '/')
 212                        pfx_length = old - a + 1;
 213                old++;
 214                new++;
 215        }
 216
 217        /* Find common suffix */
 218        old = a + len_a;
 219        new = b + len_b;
 220        sfx_length = 0;
 221        while (a <= old && b <= new && *old == *new) {
 222                if (*old == '/')
 223                        sfx_length = len_a - (old - a);
 224                old--;
 225                new--;
 226        }
 227
 228        /*
 229         * pfx{mid-a => mid-b}sfx
 230         * {pfx-a => pfx-b}sfx
 231         * pfx{sfx-a => sfx-b}
 232         * name-a => name-b
 233         */
 234        if (pfx_length + sfx_length) {
 235                int a_midlen = len_a - pfx_length - sfx_length;
 236                int b_midlen = len_b - pfx_length - sfx_length;
 237                if (a_midlen < 0) a_midlen = 0;
 238                if (b_midlen < 0) b_midlen = 0;
 239
 240                name = xmalloc(len_a + len_b - pfx_length - sfx_length + 7);
 241                sprintf(name, "%.*s{%.*s => %.*s}%s",
 242                        pfx_length, a,
 243                        a_midlen, a + pfx_length,
 244                        b_midlen, b + pfx_length,
 245                        a + len_a - sfx_length);
 246        }
 247        else {
 248                name = xmalloc(len_a + len_b + 5);
 249                sprintf(name, "%s => %s", a, b);
 250        }
 251        return name;
 252}
 253
 254struct diffstat_t {
 255        struct xdiff_emit_state xm;
 256
 257        int nr;
 258        int alloc;
 259        struct diffstat_file {
 260                char *name;
 261                unsigned is_unmerged:1;
 262                unsigned is_binary:1;
 263                unsigned is_renamed:1;
 264                unsigned int added, deleted;
 265        } **files;
 266};
 267
 268static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 269                                          const char *name_a,
 270                                          const char *name_b)
 271{
 272        struct diffstat_file *x;
 273        x = xcalloc(sizeof (*x), 1);
 274        if (diffstat->nr == diffstat->alloc) {
 275                diffstat->alloc = alloc_nr(diffstat->alloc);
 276                diffstat->files = xrealloc(diffstat->files,
 277                                diffstat->alloc * sizeof(x));
 278        }
 279        diffstat->files[diffstat->nr++] = x;
 280        if (name_b) {
 281                x->name = pprint_rename(name_a, name_b);
 282                x->is_renamed = 1;
 283        }
 284        else
 285                x->name = strdup(name_a);
 286        return x;
 287}
 288
 289static void diffstat_consume(void *priv, char *line, unsigned long len)
 290{
 291        struct diffstat_t *diffstat = priv;
 292        struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 293
 294        if (line[0] == '+')
 295                x->added++;
 296        else if (line[0] == '-')
 297                x->deleted++;
 298}
 299
 300static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 301static const char minuses[]= "----------------------------------------------------------------------";
 302
 303static void show_stats(struct diffstat_t* data)
 304{
 305        int i, len, add, del, total, adds = 0, dels = 0;
 306        int max, max_change = 0, max_len = 0;
 307        int total_files = data->nr;
 308
 309        if (data->nr == 0)
 310                return;
 311
 312        for (i = 0; i < data->nr; i++) {
 313                struct diffstat_file *file = data->files[i];
 314
 315                len = strlen(file->name);
 316                if (max_len < len)
 317                        max_len = len;
 318
 319                if (file->is_binary || file->is_unmerged)
 320                        continue;
 321                if (max_change < file->added + file->deleted)
 322                        max_change = file->added + file->deleted;
 323        }
 324
 325        for (i = 0; i < data->nr; i++) {
 326                char *prefix = "";
 327                char *name = data->files[i]->name;
 328                int added = data->files[i]->added;
 329                int deleted = data->files[i]->deleted;
 330
 331                if (0 < (len = quote_c_style(name, NULL, NULL, 0))) {
 332                        char *qname = xmalloc(len + 1);
 333                        quote_c_style(name, qname, NULL, 0);
 334                        free(name);
 335                        data->files[i]->name = name = qname;
 336                }
 337
 338                /*
 339                 * "scale" the filename
 340                 */
 341                len = strlen(name);
 342                max = max_len;
 343                if (max > 50)
 344                        max = 50;
 345                if (len > max) {
 346                        char *slash;
 347                        prefix = "...";
 348                        max -= 3;
 349                        name += len - max;
 350                        slash = strchr(name, '/');
 351                        if (slash)
 352                                name = slash;
 353                }
 354                len = max;
 355
 356                /*
 357                 * scale the add/delete
 358                 */
 359                max = max_change;
 360                if (max + len > 70)
 361                        max = 70 - len;
 362
 363                if (data->files[i]->is_binary) {
 364                        printf(" %s%-*s |  Bin\n", prefix, len, name);
 365                        goto free_diffstat_file;
 366                }
 367                else if (data->files[i]->is_unmerged) {
 368                        printf(" %s%-*s |  Unmerged\n", prefix, len, name);
 369                        goto free_diffstat_file;
 370                }
 371                else if (!data->files[i]->is_renamed &&
 372                         (added + deleted == 0)) {
 373                        total_files--;
 374                        goto free_diffstat_file;
 375                }
 376
 377                add = added;
 378                del = deleted;
 379                total = add + del;
 380                adds += add;
 381                dels += del;
 382
 383                if (max_change > 0) {
 384                        total = (total * max + max_change / 2) / max_change;
 385                        add = (add * max + max_change / 2) / max_change;
 386                        del = total - add;
 387                }
 388                printf(" %s%-*s |%5d %.*s%.*s\n", prefix,
 389                                len, name, added + deleted,
 390                                add, pluses, del, minuses);
 391        free_diffstat_file:
 392                free(data->files[i]->name);
 393                free(data->files[i]);
 394        }
 395        free(data->files);
 396        printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
 397                        total_files, adds, dels);
 398}
 399
 400static unsigned char *deflate_it(char *data,
 401                                 unsigned long size,
 402                                 unsigned long *result_size)
 403{
 404        int bound;
 405        unsigned char *deflated;
 406        z_stream stream;
 407
 408        memset(&stream, 0, sizeof(stream));
 409        deflateInit(&stream, Z_BEST_COMPRESSION);
 410        bound = deflateBound(&stream, size);
 411        deflated = xmalloc(bound);
 412        stream.next_out = deflated;
 413        stream.avail_out = bound;
 414
 415        stream.next_in = (unsigned char *)data;
 416        stream.avail_in = size;
 417        while (deflate(&stream, Z_FINISH) == Z_OK)
 418                ; /* nothing */
 419        deflateEnd(&stream);
 420        *result_size = stream.total_out;
 421        return deflated;
 422}
 423
 424static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
 425{
 426        void *cp;
 427        void *delta;
 428        void *deflated;
 429        void *data;
 430        unsigned long orig_size;
 431        unsigned long delta_size;
 432        unsigned long deflate_size;
 433        unsigned long data_size;
 434
 435        printf("GIT binary patch\n");
 436        /* We could do deflated delta, or we could do just deflated two,
 437         * whichever is smaller.
 438         */
 439        delta = NULL;
 440        deflated = deflate_it(two->ptr, two->size, &deflate_size);
 441        if (one->size && two->size) {
 442                delta = diff_delta(one->ptr, one->size,
 443                                   two->ptr, two->size,
 444                                   &delta_size, deflate_size);
 445                if (delta) {
 446                        void *to_free = delta;
 447                        orig_size = delta_size;
 448                        delta = deflate_it(delta, delta_size, &delta_size);
 449                        free(to_free);
 450                }
 451        }
 452
 453        if (delta && delta_size < deflate_size) {
 454                printf("delta %lu\n", orig_size);
 455                free(deflated);
 456                data = delta;
 457                data_size = delta_size;
 458        }
 459        else {
 460                printf("literal %lu\n", two->size);
 461                free(delta);
 462                data = deflated;
 463                data_size = deflate_size;
 464        }
 465
 466        /* emit data encoded in base85 */
 467        cp = data;
 468        while (data_size) {
 469                int bytes = (52 < data_size) ? 52 : data_size;
 470                char line[70];
 471                data_size -= bytes;
 472                if (bytes <= 26)
 473                        line[0] = bytes + 'A' - 1;
 474                else
 475                        line[0] = bytes - 26 + 'a' - 1;
 476                encode_85(line + 1, cp, bytes);
 477                cp += bytes;
 478                puts(line);
 479        }
 480        printf("\n");
 481        free(data);
 482}
 483
 484#define FIRST_FEW_BYTES 8000
 485static int mmfile_is_binary(mmfile_t *mf)
 486{
 487        long sz = mf->size;
 488        if (FIRST_FEW_BYTES < sz)
 489                sz = FIRST_FEW_BYTES;
 490        if (memchr(mf->ptr, 0, sz))
 491                return 1;
 492        return 0;
 493}
 494
 495static void builtin_diff(const char *name_a,
 496                         const char *name_b,
 497                         struct diff_filespec *one,
 498                         struct diff_filespec *two,
 499                         const char *xfrm_msg,
 500                         struct diff_options *o,
 501                         int complete_rewrite)
 502{
 503        mmfile_t mf1, mf2;
 504        const char *lbl[2];
 505        char *a_one, *b_two;
 506
 507        a_one = quote_two("a/", name_a);
 508        b_two = quote_two("b/", name_b);
 509        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
 510        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
 511        printf("diff --git %s %s\n", a_one, b_two);
 512        if (lbl[0][0] == '/') {
 513                /* /dev/null */
 514                printf("new file mode %06o\n", two->mode);
 515                if (xfrm_msg && xfrm_msg[0])
 516                        puts(xfrm_msg);
 517        }
 518        else if (lbl[1][0] == '/') {
 519                printf("deleted file mode %06o\n", one->mode);
 520                if (xfrm_msg && xfrm_msg[0])
 521                        puts(xfrm_msg);
 522        }
 523        else {
 524                if (one->mode != two->mode) {
 525                        printf("old mode %06o\n", one->mode);
 526                        printf("new mode %06o\n", two->mode);
 527                }
 528                if (xfrm_msg && xfrm_msg[0])
 529                        puts(xfrm_msg);
 530                /*
 531                 * we do not run diff between different kind
 532                 * of objects.
 533                 */
 534                if ((one->mode ^ two->mode) & S_IFMT)
 535                        goto free_ab_and_return;
 536                if (complete_rewrite) {
 537                        emit_rewrite_diff(name_a, name_b, one, two);
 538                        goto free_ab_and_return;
 539                }
 540        }
 541
 542        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 543                die("unable to read files to diff");
 544
 545        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2)) {
 546                /* Quite common confusing case */
 547                if (mf1.size == mf2.size &&
 548                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
 549                        goto free_ab_and_return;
 550                if (o->binary)
 551                        emit_binary_diff(&mf1, &mf2);
 552                else
 553                        printf("Binary files %s and %s differ\n",
 554                               lbl[0], lbl[1]);
 555        }
 556        else {
 557                /* Crazy xdl interfaces.. */
 558                const char *diffopts = getenv("GIT_DIFF_OPTS");
 559                xpparam_t xpp;
 560                xdemitconf_t xecfg;
 561                xdemitcb_t ecb;
 562                struct emit_callback ecbdata;
 563
 564                ecbdata.label_path = lbl;
 565                xpp.flags = XDF_NEED_MINIMAL;
 566                xecfg.ctxlen = 3;
 567                xecfg.flags = XDL_EMIT_FUNCNAMES;
 568                if (!diffopts)
 569                        ;
 570                else if (!strncmp(diffopts, "--unified=", 10))
 571                        xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
 572                else if (!strncmp(diffopts, "-u", 2))
 573                        xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
 574                ecb.outf = fn_out;
 575                ecb.priv = &ecbdata;
 576                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 577        }
 578
 579 free_ab_and_return:
 580        free(a_one);
 581        free(b_two);
 582        return;
 583}
 584
 585static void builtin_diffstat(const char *name_a, const char *name_b,
 586                             struct diff_filespec *one,
 587                             struct diff_filespec *two,
 588                             struct diffstat_t *diffstat,
 589                             int complete_rewrite)
 590{
 591        mmfile_t mf1, mf2;
 592        struct diffstat_file *data;
 593
 594        data = diffstat_add(diffstat, name_a, name_b);
 595
 596        if (!one || !two) {
 597                data->is_unmerged = 1;
 598                return;
 599        }
 600        if (complete_rewrite) {
 601                diff_populate_filespec(one, 0);
 602                diff_populate_filespec(two, 0);
 603                data->deleted = count_lines(one->data, one->size);
 604                data->added = count_lines(two->data, two->size);
 605                return;
 606        }
 607        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
 608                die("unable to read files to diff");
 609
 610        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
 611                data->is_binary = 1;
 612        else {
 613                /* Crazy xdl interfaces.. */
 614                xpparam_t xpp;
 615                xdemitconf_t xecfg;
 616                xdemitcb_t ecb;
 617
 618                xpp.flags = XDF_NEED_MINIMAL;
 619                xecfg.ctxlen = 0;
 620                xecfg.flags = 0;
 621                ecb.outf = xdiff_outf;
 622                ecb.priv = diffstat;
 623                xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
 624        }
 625}
 626
 627struct diff_filespec *alloc_filespec(const char *path)
 628{
 629        int namelen = strlen(path);
 630        struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
 631
 632        memset(spec, 0, sizeof(*spec));
 633        spec->path = (char *)(spec + 1);
 634        memcpy(spec->path, path, namelen+1);
 635        return spec;
 636}
 637
 638void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
 639                   unsigned short mode)
 640{
 641        if (mode) {
 642                spec->mode = canon_mode(mode);
 643                memcpy(spec->sha1, sha1, 20);
 644                spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
 645        }
 646}
 647
 648/*
 649 * Given a name and sha1 pair, if the dircache tells us the file in
 650 * the work tree has that object contents, return true, so that
 651 * prepare_temp_file() does not have to inflate and extract.
 652 */
 653static int work_tree_matches(const char *name, const unsigned char *sha1)
 654{
 655        struct cache_entry *ce;
 656        struct stat st;
 657        int pos, len;
 658
 659        /* We do not read the cache ourselves here, because the
 660         * benchmark with my previous version that always reads cache
 661         * shows that it makes things worse for diff-tree comparing
 662         * two linux-2.6 kernel trees in an already checked out work
 663         * tree.  This is because most diff-tree comparisons deal with
 664         * only a small number of files, while reading the cache is
 665         * expensive for a large project, and its cost outweighs the
 666         * savings we get by not inflating the object to a temporary
 667         * file.  Practically, this code only helps when we are used
 668         * by diff-cache --cached, which does read the cache before
 669         * calling us.
 670         */
 671        if (!active_cache)
 672                return 0;
 673
 674        len = strlen(name);
 675        pos = cache_name_pos(name, len);
 676        if (pos < 0)
 677                return 0;
 678        ce = active_cache[pos];
 679        if ((lstat(name, &st) < 0) ||
 680            !S_ISREG(st.st_mode) || /* careful! */
 681            ce_match_stat(ce, &st, 0) ||
 682            memcmp(sha1, ce->sha1, 20))
 683                return 0;
 684        /* we return 1 only when we can stat, it is a regular file,
 685         * stat information matches, and sha1 recorded in the cache
 686         * matches.  I.e. we know the file in the work tree really is
 687         * the same as the <name, sha1> pair.
 688         */
 689        return 1;
 690}
 691
 692static struct sha1_size_cache {
 693        unsigned char sha1[20];
 694        unsigned long size;
 695} **sha1_size_cache;
 696static int sha1_size_cache_nr, sha1_size_cache_alloc;
 697
 698static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
 699                                                 int find_only,
 700                                                 unsigned long size)
 701{
 702        int first, last;
 703        struct sha1_size_cache *e;
 704
 705        first = 0;
 706        last = sha1_size_cache_nr;
 707        while (last > first) {
 708                int cmp, next = (last + first) >> 1;
 709                e = sha1_size_cache[next];
 710                cmp = memcmp(e->sha1, sha1, 20);
 711                if (!cmp)
 712                        return e;
 713                if (cmp < 0) {
 714                        last = next;
 715                        continue;
 716                }
 717                first = next+1;
 718        }
 719        /* not found */
 720        if (find_only)
 721                return NULL;
 722        /* insert to make it at "first" */
 723        if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
 724                sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
 725                sha1_size_cache = xrealloc(sha1_size_cache,
 726                                           sha1_size_cache_alloc *
 727                                           sizeof(*sha1_size_cache));
 728        }
 729        sha1_size_cache_nr++;
 730        if (first < sha1_size_cache_nr)
 731                memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
 732                        (sha1_size_cache_nr - first - 1) *
 733                        sizeof(*sha1_size_cache));
 734        e = xmalloc(sizeof(struct sha1_size_cache));
 735        sha1_size_cache[first] = e;
 736        memcpy(e->sha1, sha1, 20);
 737        e->size = size;
 738        return e;
 739}
 740
 741/*
 742 * While doing rename detection and pickaxe operation, we may need to
 743 * grab the data for the blob (or file) for our own in-core comparison.
 744 * diff_filespec has data and size fields for this purpose.
 745 */
 746int diff_populate_filespec(struct diff_filespec *s, int size_only)
 747{
 748        int err = 0;
 749        if (!DIFF_FILE_VALID(s))
 750                die("internal error: asking to populate invalid file.");
 751        if (S_ISDIR(s->mode))
 752                return -1;
 753
 754        if (!use_size_cache)
 755                size_only = 0;
 756
 757        if (s->data)
 758                return err;
 759        if (!s->sha1_valid ||
 760            work_tree_matches(s->path, s->sha1)) {
 761                struct stat st;
 762                int fd;
 763                if (lstat(s->path, &st) < 0) {
 764                        if (errno == ENOENT) {
 765                        err_empty:
 766                                err = -1;
 767                        empty:
 768                                s->data = "";
 769                                s->size = 0;
 770                                return err;
 771                        }
 772                }
 773                s->size = st.st_size;
 774                if (!s->size)
 775                        goto empty;
 776                if (size_only)
 777                        return 0;
 778                if (S_ISLNK(st.st_mode)) {
 779                        int ret;
 780                        s->data = xmalloc(s->size);
 781                        s->should_free = 1;
 782                        ret = readlink(s->path, s->data, s->size);
 783                        if (ret < 0) {
 784                                free(s->data);
 785                                goto err_empty;
 786                        }
 787                        return 0;
 788                }
 789                fd = open(s->path, O_RDONLY);
 790                if (fd < 0)
 791                        goto err_empty;
 792                s->data = mmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
 793                close(fd);
 794                if (s->data == MAP_FAILED)
 795                        goto err_empty;
 796                s->should_munmap = 1;
 797        }
 798        else {
 799                char type[20];
 800                struct sha1_size_cache *e;
 801
 802                if (size_only) {
 803                        e = locate_size_cache(s->sha1, 1, 0);
 804                        if (e) {
 805                                s->size = e->size;
 806                                return 0;
 807                        }
 808                        if (!sha1_object_info(s->sha1, type, &s->size))
 809                                locate_size_cache(s->sha1, 0, s->size);
 810                }
 811                else {
 812                        s->data = read_sha1_file(s->sha1, type, &s->size);
 813                        s->should_free = 1;
 814                }
 815        }
 816        return 0;
 817}
 818
 819void diff_free_filespec_data(struct diff_filespec *s)
 820{
 821        if (s->should_free)
 822                free(s->data);
 823        else if (s->should_munmap)
 824                munmap(s->data, s->size);
 825        s->should_free = s->should_munmap = 0;
 826        s->data = NULL;
 827        free(s->cnt_data);
 828        s->cnt_data = NULL;
 829}
 830
 831static void prep_temp_blob(struct diff_tempfile *temp,
 832                           void *blob,
 833                           unsigned long size,
 834                           const unsigned char *sha1,
 835                           int mode)
 836{
 837        int fd;
 838
 839        fd = git_mkstemp(temp->tmp_path, TEMPFILE_PATH_LEN, ".diff_XXXXXX");
 840        if (fd < 0)
 841                die("unable to create temp-file");
 842        if (write(fd, blob, size) != size)
 843                die("unable to write temp-file");
 844        close(fd);
 845        temp->name = temp->tmp_path;
 846        strcpy(temp->hex, sha1_to_hex(sha1));
 847        temp->hex[40] = 0;
 848        sprintf(temp->mode, "%06o", mode);
 849}
 850
 851static void prepare_temp_file(const char *name,
 852                              struct diff_tempfile *temp,
 853                              struct diff_filespec *one)
 854{
 855        if (!DIFF_FILE_VALID(one)) {
 856        not_a_valid_file:
 857                /* A '-' entry produces this for file-2, and
 858                 * a '+' entry produces this for file-1.
 859                 */
 860                temp->name = "/dev/null";
 861                strcpy(temp->hex, ".");
 862                strcpy(temp->mode, ".");
 863                return;
 864        }
 865
 866        if (!one->sha1_valid ||
 867            work_tree_matches(name, one->sha1)) {
 868                struct stat st;
 869                if (lstat(name, &st) < 0) {
 870                        if (errno == ENOENT)
 871                                goto not_a_valid_file;
 872                        die("stat(%s): %s", name, strerror(errno));
 873                }
 874                if (S_ISLNK(st.st_mode)) {
 875                        int ret;
 876                        char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
 877                        if (sizeof(buf) <= st.st_size)
 878                                die("symlink too long: %s", name);
 879                        ret = readlink(name, buf, st.st_size);
 880                        if (ret < 0)
 881                                die("readlink(%s)", name);
 882                        prep_temp_blob(temp, buf, st.st_size,
 883                                       (one->sha1_valid ?
 884                                        one->sha1 : null_sha1),
 885                                       (one->sha1_valid ?
 886                                        one->mode : S_IFLNK));
 887                }
 888                else {
 889                        /* we can borrow from the file in the work tree */
 890                        temp->name = name;
 891                        if (!one->sha1_valid)
 892                                strcpy(temp->hex, sha1_to_hex(null_sha1));
 893                        else
 894                                strcpy(temp->hex, sha1_to_hex(one->sha1));
 895                        /* Even though we may sometimes borrow the
 896                         * contents from the work tree, we always want
 897                         * one->mode.  mode is trustworthy even when
 898                         * !(one->sha1_valid), as long as
 899                         * DIFF_FILE_VALID(one).
 900                         */
 901                        sprintf(temp->mode, "%06o", one->mode);
 902                }
 903                return;
 904        }
 905        else {
 906                if (diff_populate_filespec(one, 0))
 907                        die("cannot read data blob for %s", one->path);
 908                prep_temp_blob(temp, one->data, one->size,
 909                               one->sha1, one->mode);
 910        }
 911}
 912
 913static void remove_tempfile(void)
 914{
 915        int i;
 916
 917        for (i = 0; i < 2; i++)
 918                if (diff_temp[i].name == diff_temp[i].tmp_path) {
 919                        unlink(diff_temp[i].name);
 920                        diff_temp[i].name = NULL;
 921                }
 922}
 923
 924static void remove_tempfile_on_signal(int signo)
 925{
 926        remove_tempfile();
 927        signal(SIGINT, SIG_DFL);
 928        raise(signo);
 929}
 930
 931static int spawn_prog(const char *pgm, const char **arg)
 932{
 933        pid_t pid;
 934        int status;
 935
 936        fflush(NULL);
 937        pid = fork();
 938        if (pid < 0)
 939                die("unable to fork");
 940        if (!pid) {
 941                execvp(pgm, (char *const*) arg);
 942                exit(255);
 943        }
 944
 945        while (waitpid(pid, &status, 0) < 0) {
 946                if (errno == EINTR)
 947                        continue;
 948                return -1;
 949        }
 950
 951        /* Earlier we did not check the exit status because
 952         * diff exits non-zero if files are different, and
 953         * we are not interested in knowing that.  It was a
 954         * mistake which made it harder to quit a diff-*
 955         * session that uses the git-apply-patch-script as
 956         * the GIT_EXTERNAL_DIFF.  A custom GIT_EXTERNAL_DIFF
 957         * should also exit non-zero only when it wants to
 958         * abort the entire diff-* session.
 959         */
 960        if (WIFEXITED(status) && !WEXITSTATUS(status))
 961                return 0;
 962        return -1;
 963}
 964
 965/* An external diff command takes:
 966 *
 967 * diff-cmd name infile1 infile1-sha1 infile1-mode \
 968 *               infile2 infile2-sha1 infile2-mode [ rename-to ]
 969 *
 970 */
 971static void run_external_diff(const char *pgm,
 972                              const char *name,
 973                              const char *other,
 974                              struct diff_filespec *one,
 975                              struct diff_filespec *two,
 976                              const char *xfrm_msg,
 977                              int complete_rewrite)
 978{
 979        const char *spawn_arg[10];
 980        struct diff_tempfile *temp = diff_temp;
 981        int retval;
 982        static int atexit_asked = 0;
 983        const char *othername;
 984        const char **arg = &spawn_arg[0];
 985
 986        othername = (other? other : name);
 987        if (one && two) {
 988                prepare_temp_file(name, &temp[0], one);
 989                prepare_temp_file(othername, &temp[1], two);
 990                if (! atexit_asked &&
 991                    (temp[0].name == temp[0].tmp_path ||
 992                     temp[1].name == temp[1].tmp_path)) {
 993                        atexit_asked = 1;
 994                        atexit(remove_tempfile);
 995                }
 996                signal(SIGINT, remove_tempfile_on_signal);
 997        }
 998
 999        if (one && two) {
1000                *arg++ = pgm;
1001                *arg++ = name;
1002                *arg++ = temp[0].name;
1003                *arg++ = temp[0].hex;
1004                *arg++ = temp[0].mode;
1005                *arg++ = temp[1].name;
1006                *arg++ = temp[1].hex;
1007                *arg++ = temp[1].mode;
1008                if (other) {
1009                        *arg++ = other;
1010                        *arg++ = xfrm_msg;
1011                }
1012        } else {
1013                *arg++ = pgm;
1014                *arg++ = name;
1015        }
1016        *arg = NULL;
1017        retval = spawn_prog(pgm, spawn_arg);
1018        remove_tempfile();
1019        if (retval) {
1020                fprintf(stderr, "external diff died, stopping at %s.\n", name);
1021                exit(1);
1022        }
1023}
1024
1025static void run_diff_cmd(const char *pgm,
1026                         const char *name,
1027                         const char *other,
1028                         struct diff_filespec *one,
1029                         struct diff_filespec *two,
1030                         const char *xfrm_msg,
1031                         struct diff_options *o,
1032                         int complete_rewrite)
1033{
1034        if (pgm) {
1035                run_external_diff(pgm, name, other, one, two, xfrm_msg,
1036                                  complete_rewrite);
1037                return;
1038        }
1039        if (one && two)
1040                builtin_diff(name, other ? other : name,
1041                             one, two, xfrm_msg, o, complete_rewrite);
1042        else
1043                printf("* Unmerged path %s\n", name);
1044}
1045
1046static void diff_fill_sha1_info(struct diff_filespec *one)
1047{
1048        if (DIFF_FILE_VALID(one)) {
1049                if (!one->sha1_valid) {
1050                        struct stat st;
1051                        if (lstat(one->path, &st) < 0)
1052                                die("stat %s", one->path);
1053                        if (index_path(one->sha1, one->path, &st, 0))
1054                                die("cannot hash %s\n", one->path);
1055                }
1056        }
1057        else
1058                memset(one->sha1, 0, 20);
1059}
1060
1061static void run_diff(struct diff_filepair *p, struct diff_options *o)
1062{
1063        const char *pgm = external_diff();
1064        char msg[PATH_MAX*2+300], *xfrm_msg;
1065        struct diff_filespec *one;
1066        struct diff_filespec *two;
1067        const char *name;
1068        const char *other;
1069        char *name_munged, *other_munged;
1070        int complete_rewrite = 0;
1071        int len;
1072
1073        if (DIFF_PAIR_UNMERGED(p)) {
1074                /* unmerged */
1075                run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
1076                return;
1077        }
1078
1079        name = p->one->path;
1080        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1081        name_munged = quote_one(name);
1082        other_munged = quote_one(other);
1083        one = p->one; two = p->two;
1084
1085        diff_fill_sha1_info(one);
1086        diff_fill_sha1_info(two);
1087
1088        len = 0;
1089        switch (p->status) {
1090        case DIFF_STATUS_COPIED:
1091                len += snprintf(msg + len, sizeof(msg) - len,
1092                                "similarity index %d%%\n"
1093                                "copy from %s\n"
1094                                "copy to %s\n",
1095                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
1096                                name_munged, other_munged);
1097                break;
1098        case DIFF_STATUS_RENAMED:
1099                len += snprintf(msg + len, sizeof(msg) - len,
1100                                "similarity index %d%%\n"
1101                                "rename from %s\n"
1102                                "rename to %s\n",
1103                                (int)(0.5 + p->score * 100.0/MAX_SCORE),
1104                                name_munged, other_munged);
1105                break;
1106        case DIFF_STATUS_MODIFIED:
1107                if (p->score) {
1108                        len += snprintf(msg + len, sizeof(msg) - len,
1109                                        "dissimilarity index %d%%\n",
1110                                        (int)(0.5 + p->score *
1111                                              100.0/MAX_SCORE));
1112                        complete_rewrite = 1;
1113                        break;
1114                }
1115                /* fallthru */
1116        default:
1117                /* nothing */
1118                ;
1119        }
1120
1121        if (memcmp(one->sha1, two->sha1, 20)) {
1122                int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
1123
1124                len += snprintf(msg + len, sizeof(msg) - len,
1125                                "index %.*s..%.*s",
1126                                abbrev, sha1_to_hex(one->sha1),
1127                                abbrev, sha1_to_hex(two->sha1));
1128                if (one->mode == two->mode)
1129                        len += snprintf(msg + len, sizeof(msg) - len,
1130                                        " %06o", one->mode);
1131                len += snprintf(msg + len, sizeof(msg) - len, "\n");
1132        }
1133
1134        if (len)
1135                msg[--len] = 0;
1136        xfrm_msg = len ? msg : NULL;
1137
1138        if (!pgm &&
1139            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
1140            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
1141                /* a filepair that changes between file and symlink
1142                 * needs to be split into deletion and creation.
1143                 */
1144                struct diff_filespec *null = alloc_filespec(two->path);
1145                run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
1146                free(null);
1147                null = alloc_filespec(one->path);
1148                run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
1149                free(null);
1150        }
1151        else
1152                run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
1153                             complete_rewrite);
1154
1155        free(name_munged);
1156        free(other_munged);
1157}
1158
1159static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
1160                         struct diffstat_t *diffstat)
1161{
1162        const char *name;
1163        const char *other;
1164        int complete_rewrite = 0;
1165
1166        if (DIFF_PAIR_UNMERGED(p)) {
1167                /* unmerged */
1168                builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, 0);
1169                return;
1170        }
1171
1172        name = p->one->path;
1173        other = (strcmp(name, p->two->path) ? p->two->path : NULL);
1174
1175        diff_fill_sha1_info(p->one);
1176        diff_fill_sha1_info(p->two);
1177
1178        if (p->status == DIFF_STATUS_MODIFIED && p->score)
1179                complete_rewrite = 1;
1180        builtin_diffstat(name, other, p->one, p->two, diffstat, complete_rewrite);
1181}
1182
1183void diff_setup(struct diff_options *options)
1184{
1185        memset(options, 0, sizeof(*options));
1186        options->output_format = DIFF_FORMAT_RAW;
1187        options->line_termination = '\n';
1188        options->break_opt = -1;
1189        options->rename_limit = -1;
1190
1191        options->change = diff_change;
1192        options->add_remove = diff_addremove;
1193}
1194
1195int diff_setup_done(struct diff_options *options)
1196{
1197        if ((options->find_copies_harder &&
1198             options->detect_rename != DIFF_DETECT_COPY) ||
1199            (0 <= options->rename_limit && !options->detect_rename))
1200                return -1;
1201
1202        /*
1203         * These cases always need recursive; we do not drop caller-supplied
1204         * recursive bits for other formats here.
1205         */
1206        if ((options->output_format == DIFF_FORMAT_PATCH) ||
1207            (options->output_format == DIFF_FORMAT_DIFFSTAT))
1208                options->recursive = 1;
1209
1210        if (options->detect_rename && options->rename_limit < 0)
1211                options->rename_limit = diff_rename_limit_default;
1212        if (options->setup & DIFF_SETUP_USE_CACHE) {
1213                if (!active_cache)
1214                        /* read-cache does not die even when it fails
1215                         * so it is safe for us to do this here.  Also
1216                         * it does not smudge active_cache or active_nr
1217                         * when it fails, so we do not have to worry about
1218                         * cleaning it up ourselves either.
1219                         */
1220                        read_cache();
1221        }
1222        if (options->setup & DIFF_SETUP_USE_SIZE_CACHE)
1223                use_size_cache = 1;
1224        if (options->abbrev <= 0 || 40 < options->abbrev)
1225                options->abbrev = 40; /* full */
1226
1227        return 0;
1228}
1229
1230int diff_opt_parse(struct diff_options *options, const char **av, int ac)
1231{
1232        const char *arg = av[0];
1233        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
1234                options->output_format = DIFF_FORMAT_PATCH;
1235        else if (!strcmp(arg, "--patch-with-raw")) {
1236                options->output_format = DIFF_FORMAT_PATCH;
1237                options->with_raw = 1;
1238        }
1239        else if (!strcmp(arg, "--stat"))
1240                options->output_format = DIFF_FORMAT_DIFFSTAT;
1241        else if (!strcmp(arg, "--patch-with-stat")) {
1242                options->output_format = DIFF_FORMAT_PATCH;
1243                options->with_stat = 1;
1244        }
1245        else if (!strcmp(arg, "-z"))
1246                options->line_termination = 0;
1247        else if (!strncmp(arg, "-l", 2))
1248                options->rename_limit = strtoul(arg+2, NULL, 10);
1249        else if (!strcmp(arg, "--full-index"))
1250                options->full_index = 1;
1251        else if (!strcmp(arg, "--binary")) {
1252                options->output_format = DIFF_FORMAT_PATCH;
1253                options->full_index = options->binary = 1;
1254        }
1255        else if (!strcmp(arg, "--name-only"))
1256                options->output_format = DIFF_FORMAT_NAME;
1257        else if (!strcmp(arg, "--name-status"))
1258                options->output_format = DIFF_FORMAT_NAME_STATUS;
1259        else if (!strcmp(arg, "-R"))
1260                options->reverse_diff = 1;
1261        else if (!strncmp(arg, "-S", 2))
1262                options->pickaxe = arg + 2;
1263        else if (!strcmp(arg, "-s"))
1264                options->output_format = DIFF_FORMAT_NO_OUTPUT;
1265        else if (!strncmp(arg, "-O", 2))
1266                options->orderfile = arg + 2;
1267        else if (!strncmp(arg, "--diff-filter=", 14))
1268                options->filter = arg + 14;
1269        else if (!strcmp(arg, "--pickaxe-all"))
1270                options->pickaxe_opts = DIFF_PICKAXE_ALL;
1271        else if (!strcmp(arg, "--pickaxe-regex"))
1272                options->pickaxe_opts = DIFF_PICKAXE_REGEX;
1273        else if (!strncmp(arg, "-B", 2)) {
1274                if ((options->break_opt =
1275                     diff_scoreopt_parse(arg)) == -1)
1276                        return -1;
1277        }
1278        else if (!strncmp(arg, "-M", 2)) {
1279                if ((options->rename_score =
1280                     diff_scoreopt_parse(arg)) == -1)
1281                        return -1;
1282                options->detect_rename = DIFF_DETECT_RENAME;
1283        }
1284        else if (!strncmp(arg, "-C", 2)) {
1285                if ((options->rename_score =
1286                     diff_scoreopt_parse(arg)) == -1)
1287                        return -1;
1288                options->detect_rename = DIFF_DETECT_COPY;
1289        }
1290        else if (!strcmp(arg, "--find-copies-harder"))
1291                options->find_copies_harder = 1;
1292        else if (!strcmp(arg, "--abbrev"))
1293                options->abbrev = DEFAULT_ABBREV;
1294        else if (!strncmp(arg, "--abbrev=", 9)) {
1295                options->abbrev = strtoul(arg + 9, NULL, 10);
1296                if (options->abbrev < MINIMUM_ABBREV)
1297                        options->abbrev = MINIMUM_ABBREV;
1298                else if (40 < options->abbrev)
1299                        options->abbrev = 40;
1300        }
1301        else
1302                return 0;
1303        return 1;
1304}
1305
1306static int parse_num(const char **cp_p)
1307{
1308        unsigned long num, scale;
1309        int ch, dot;
1310        const char *cp = *cp_p;
1311
1312        num = 0;
1313        scale = 1;
1314        dot = 0;
1315        for(;;) {
1316                ch = *cp;
1317                if ( !dot && ch == '.' ) {
1318                        scale = 1;
1319                        dot = 1;
1320                } else if ( ch == '%' ) {
1321                        scale = dot ? scale*100 : 100;
1322                        cp++;   /* % is always at the end */
1323                        break;
1324                } else if ( ch >= '0' && ch <= '9' ) {
1325                        if ( scale < 100000 ) {
1326                                scale *= 10;
1327                                num = (num*10) + (ch-'0');
1328                        }
1329                } else {
1330                        break;
1331                }
1332                cp++;
1333        }
1334        *cp_p = cp;
1335
1336        /* user says num divided by scale and we say internally that
1337         * is MAX_SCORE * num / scale.
1338         */
1339        return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale);
1340}
1341
1342int diff_scoreopt_parse(const char *opt)
1343{
1344        int opt1, opt2, cmd;
1345
1346        if (*opt++ != '-')
1347                return -1;
1348        cmd = *opt++;
1349        if (cmd != 'M' && cmd != 'C' && cmd != 'B')
1350                return -1; /* that is not a -M, -C nor -B option */
1351
1352        opt1 = parse_num(&opt);
1353        if (cmd != 'B')
1354                opt2 = 0;
1355        else {
1356                if (*opt == 0)
1357                        opt2 = 0;
1358                else if (*opt != '/')
1359                        return -1; /* we expect -B80/99 or -B80 */
1360                else {
1361                        opt++;
1362                        opt2 = parse_num(&opt);
1363                }
1364        }
1365        if (*opt != 0)
1366                return -1;
1367        return opt1 | (opt2 << 16);
1368}
1369
1370struct diff_queue_struct diff_queued_diff;
1371
1372void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
1373{
1374        if (queue->alloc <= queue->nr) {
1375                queue->alloc = alloc_nr(queue->alloc);
1376                queue->queue = xrealloc(queue->queue,
1377                                        sizeof(dp) * queue->alloc);
1378        }
1379        queue->queue[queue->nr++] = dp;
1380}
1381
1382struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
1383                                 struct diff_filespec *one,
1384                                 struct diff_filespec *two)
1385{
1386        struct diff_filepair *dp = xmalloc(sizeof(*dp));
1387        dp->one = one;
1388        dp->two = two;
1389        dp->score = 0;
1390        dp->status = 0;
1391        dp->source_stays = 0;
1392        dp->broken_pair = 0;
1393        if (queue)
1394                diff_q(queue, dp);
1395        return dp;
1396}
1397
1398void diff_free_filepair(struct diff_filepair *p)
1399{
1400        diff_free_filespec_data(p->one);
1401        diff_free_filespec_data(p->two);
1402        free(p->one);
1403        free(p->two);
1404        free(p);
1405}
1406
1407/* This is different from find_unique_abbrev() in that
1408 * it stuffs the result with dots for alignment.
1409 */
1410const char *diff_unique_abbrev(const unsigned char *sha1, int len)
1411{
1412        int abblen;
1413        const char *abbrev;
1414        if (len == 40)
1415                return sha1_to_hex(sha1);
1416
1417        abbrev = find_unique_abbrev(sha1, len);
1418        if (!abbrev)
1419                return sha1_to_hex(sha1);
1420        abblen = strlen(abbrev);
1421        if (abblen < 37) {
1422                static char hex[41];
1423                if (len < abblen && abblen <= len + 2)
1424                        sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
1425                else
1426                        sprintf(hex, "%s...", abbrev);
1427                return hex;
1428        }
1429        return sha1_to_hex(sha1);
1430}
1431
1432static void diff_flush_raw(struct diff_filepair *p,
1433                           int line_termination,
1434                           int inter_name_termination,
1435                           struct diff_options *options,
1436                           int output_format)
1437{
1438        int two_paths;
1439        char status[10];
1440        int abbrev = options->abbrev;
1441        const char *path_one, *path_two;
1442
1443        path_one = p->one->path;
1444        path_two = p->two->path;
1445        if (line_termination) {
1446                path_one = quote_one(path_one);
1447                path_two = quote_one(path_two);
1448        }
1449
1450        if (p->score)
1451                sprintf(status, "%c%03d", p->status,
1452                        (int)(0.5 + p->score * 100.0/MAX_SCORE));
1453        else {
1454                status[0] = p->status;
1455                status[1] = 0;
1456        }
1457        switch (p->status) {
1458        case DIFF_STATUS_COPIED:
1459        case DIFF_STATUS_RENAMED:
1460                two_paths = 1;
1461                break;
1462        case DIFF_STATUS_ADDED:
1463        case DIFF_STATUS_DELETED:
1464                two_paths = 0;
1465                break;
1466        default:
1467                two_paths = 0;
1468                break;
1469        }
1470        if (output_format != DIFF_FORMAT_NAME_STATUS) {
1471                printf(":%06o %06o %s ",
1472                       p->one->mode, p->two->mode,
1473                       diff_unique_abbrev(p->one->sha1, abbrev));
1474                printf("%s ",
1475                       diff_unique_abbrev(p->two->sha1, abbrev));
1476        }
1477        printf("%s%c%s", status, inter_name_termination, path_one);
1478        if (two_paths)
1479                printf("%c%s", inter_name_termination, path_two);
1480        putchar(line_termination);
1481        if (path_one != p->one->path)
1482                free((void*)path_one);
1483        if (path_two != p->two->path)
1484                free((void*)path_two);
1485}
1486
1487static void diff_flush_name(struct diff_filepair *p,
1488                            int inter_name_termination,
1489                            int line_termination)
1490{
1491        char *path = p->two->path;
1492
1493        if (line_termination)
1494                path = quote_one(p->two->path);
1495        else
1496                path = p->two->path;
1497        printf("%s%c", path, line_termination);
1498        if (p->two->path != path)
1499                free(path);
1500}
1501
1502int diff_unmodified_pair(struct diff_filepair *p)
1503{
1504        /* This function is written stricter than necessary to support
1505         * the currently implemented transformers, but the idea is to
1506         * let transformers to produce diff_filepairs any way they want,
1507         * and filter and clean them up here before producing the output.
1508         */
1509        struct diff_filespec *one, *two;
1510
1511        if (DIFF_PAIR_UNMERGED(p))
1512                return 0; /* unmerged is interesting */
1513
1514        one = p->one;
1515        two = p->two;
1516
1517        /* deletion, addition, mode or type change
1518         * and rename are all interesting.
1519         */
1520        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
1521            DIFF_PAIR_MODE_CHANGED(p) ||
1522            strcmp(one->path, two->path))
1523                return 0;
1524
1525        /* both are valid and point at the same path.  that is, we are
1526         * dealing with a change.
1527         */
1528        if (one->sha1_valid && two->sha1_valid &&
1529            !memcmp(one->sha1, two->sha1, sizeof(one->sha1)))
1530                return 1; /* no change */
1531        if (!one->sha1_valid && !two->sha1_valid)
1532                return 1; /* both look at the same file on the filesystem. */
1533        return 0;
1534}
1535
1536static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
1537{
1538        if (diff_unmodified_pair(p))
1539                return;
1540
1541        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1542            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1543                return; /* no tree diffs in patch format */
1544
1545        run_diff(p, o);
1546}
1547
1548static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
1549                            struct diffstat_t *diffstat)
1550{
1551        if (diff_unmodified_pair(p))
1552                return;
1553
1554        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
1555            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
1556                return; /* no tree diffs in patch format */
1557
1558        run_diffstat(p, o, diffstat);
1559}
1560
1561int diff_queue_is_empty(void)
1562{
1563        struct diff_queue_struct *q = &diff_queued_diff;
1564        int i;
1565        for (i = 0; i < q->nr; i++)
1566                if (!diff_unmodified_pair(q->queue[i]))
1567                        return 0;
1568        return 1;
1569}
1570
1571#if DIFF_DEBUG
1572void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
1573{
1574        fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
1575                x, one ? one : "",
1576                s->path,
1577                DIFF_FILE_VALID(s) ? "valid" : "invalid",
1578                s->mode,
1579                s->sha1_valid ? sha1_to_hex(s->sha1) : "");
1580        fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
1581                x, one ? one : "",
1582                s->size, s->xfrm_flags);
1583}
1584
1585void diff_debug_filepair(const struct diff_filepair *p, int i)
1586{
1587        diff_debug_filespec(p->one, i, "one");
1588        diff_debug_filespec(p->two, i, "two");
1589        fprintf(stderr, "score %d, status %c stays %d broken %d\n",
1590                p->score, p->status ? p->status : '?',
1591                p->source_stays, p->broken_pair);
1592}
1593
1594void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
1595{
1596        int i;
1597        if (msg)
1598                fprintf(stderr, "%s\n", msg);
1599        fprintf(stderr, "q->nr = %d\n", q->nr);
1600        for (i = 0; i < q->nr; i++) {
1601                struct diff_filepair *p = q->queue[i];
1602                diff_debug_filepair(p, i);
1603        }
1604}
1605#endif
1606
1607static void diff_resolve_rename_copy(void)
1608{
1609        int i, j;
1610        struct diff_filepair *p, *pp;
1611        struct diff_queue_struct *q = &diff_queued_diff;
1612
1613        diff_debug_queue("resolve-rename-copy", q);
1614
1615        for (i = 0; i < q->nr; i++) {
1616                p = q->queue[i];
1617                p->status = 0; /* undecided */
1618                if (DIFF_PAIR_UNMERGED(p))
1619                        p->status = DIFF_STATUS_UNMERGED;
1620                else if (!DIFF_FILE_VALID(p->one))
1621                        p->status = DIFF_STATUS_ADDED;
1622                else if (!DIFF_FILE_VALID(p->two))
1623                        p->status = DIFF_STATUS_DELETED;
1624                else if (DIFF_PAIR_TYPE_CHANGED(p))
1625                        p->status = DIFF_STATUS_TYPE_CHANGED;
1626
1627                /* from this point on, we are dealing with a pair
1628                 * whose both sides are valid and of the same type, i.e.
1629                 * either in-place edit or rename/copy edit.
1630                 */
1631                else if (DIFF_PAIR_RENAME(p)) {
1632                        if (p->source_stays) {
1633                                p->status = DIFF_STATUS_COPIED;
1634                                continue;
1635                        }
1636                        /* See if there is some other filepair that
1637                         * copies from the same source as us.  If so
1638                         * we are a copy.  Otherwise we are either a
1639                         * copy if the path stays, or a rename if it
1640                         * does not, but we already handled "stays" case.
1641                         */
1642                        for (j = i + 1; j < q->nr; j++) {
1643                                pp = q->queue[j];
1644                                if (strcmp(pp->one->path, p->one->path))
1645                                        continue; /* not us */
1646                                if (!DIFF_PAIR_RENAME(pp))
1647                                        continue; /* not a rename/copy */
1648                                /* pp is a rename/copy from the same source */
1649                                p->status = DIFF_STATUS_COPIED;
1650                                break;
1651                        }
1652                        if (!p->status)
1653                                p->status = DIFF_STATUS_RENAMED;
1654                }
1655                else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
1656                         p->one->mode != p->two->mode)
1657                        p->status = DIFF_STATUS_MODIFIED;
1658                else {
1659                        /* This is a "no-change" entry and should not
1660                         * happen anymore, but prepare for broken callers.
1661                         */
1662                        error("feeding unmodified %s to diffcore",
1663                              p->one->path);
1664                        p->status = DIFF_STATUS_UNKNOWN;
1665                }
1666        }
1667        diff_debug_queue("resolve-rename-copy done", q);
1668}
1669
1670static void flush_one_pair(struct diff_filepair *p,
1671                           int diff_output_format,
1672                           struct diff_options *options,
1673                           struct diffstat_t *diffstat)
1674{
1675        int inter_name_termination = '\t';
1676        int line_termination = options->line_termination;
1677        if (!line_termination)
1678                inter_name_termination = 0;
1679
1680        switch (p->status) {
1681        case DIFF_STATUS_UNKNOWN:
1682                break;
1683        case 0:
1684                die("internal error in diff-resolve-rename-copy");
1685                break;
1686        default:
1687                switch (diff_output_format) {
1688                case DIFF_FORMAT_DIFFSTAT:
1689                        diff_flush_stat(p, options, diffstat);
1690                        break;
1691                case DIFF_FORMAT_PATCH:
1692                        diff_flush_patch(p, options);
1693                        break;
1694                case DIFF_FORMAT_RAW:
1695                case DIFF_FORMAT_NAME_STATUS:
1696                        diff_flush_raw(p, line_termination,
1697                                       inter_name_termination,
1698                                       options, diff_output_format);
1699                        break;
1700                case DIFF_FORMAT_NAME:
1701                        diff_flush_name(p,
1702                                        inter_name_termination,
1703                                        line_termination);
1704                        break;
1705                case DIFF_FORMAT_NO_OUTPUT:
1706                        break;
1707                }
1708        }
1709}
1710
1711void diff_flush(struct diff_options *options)
1712{
1713        struct diff_queue_struct *q = &diff_queued_diff;
1714        int i;
1715        int diff_output_format = options->output_format;
1716        struct diffstat_t *diffstat = NULL;
1717
1718        if (diff_output_format == DIFF_FORMAT_DIFFSTAT || options->with_stat) {
1719                diffstat = xcalloc(sizeof (struct diffstat_t), 1);
1720                diffstat->xm.consume = diffstat_consume;
1721        }
1722
1723        if (options->with_raw) {
1724                for (i = 0; i < q->nr; i++) {
1725                        struct diff_filepair *p = q->queue[i];
1726                        flush_one_pair(p, DIFF_FORMAT_RAW, options, NULL);
1727                }
1728                putchar(options->line_termination);
1729        }
1730        if (options->with_stat) {
1731                for (i = 0; i < q->nr; i++) {
1732                        struct diff_filepair *p = q->queue[i];
1733                        flush_one_pair(p, DIFF_FORMAT_DIFFSTAT, options,
1734                                       diffstat);
1735                }
1736                show_stats(diffstat);
1737                free(diffstat);
1738                diffstat = NULL;
1739                putchar(options->line_termination);
1740        }
1741        for (i = 0; i < q->nr; i++) {
1742                struct diff_filepair *p = q->queue[i];
1743                flush_one_pair(p, diff_output_format, options, diffstat);
1744                diff_free_filepair(p);
1745        }
1746
1747        if (diffstat) {
1748                show_stats(diffstat);
1749                free(diffstat);
1750        }
1751
1752        free(q->queue);
1753        q->queue = NULL;
1754        q->nr = q->alloc = 0;
1755}
1756
1757static void diffcore_apply_filter(const char *filter)
1758{
1759        int i;
1760        struct diff_queue_struct *q = &diff_queued_diff;
1761        struct diff_queue_struct outq;
1762        outq.queue = NULL;
1763        outq.nr = outq.alloc = 0;
1764
1765        if (!filter)
1766                return;
1767
1768        if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
1769                int found;
1770                for (i = found = 0; !found && i < q->nr; i++) {
1771                        struct diff_filepair *p = q->queue[i];
1772                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1773                             ((p->score &&
1774                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1775                              (!p->score &&
1776                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1777                            ((p->status != DIFF_STATUS_MODIFIED) &&
1778                             strchr(filter, p->status)))
1779                                found++;
1780                }
1781                if (found)
1782                        return;
1783
1784                /* otherwise we will clear the whole queue
1785                 * by copying the empty outq at the end of this
1786                 * function, but first clear the current entries
1787                 * in the queue.
1788                 */
1789                for (i = 0; i < q->nr; i++)
1790                        diff_free_filepair(q->queue[i]);
1791        }
1792        else {
1793                /* Only the matching ones */
1794                for (i = 0; i < q->nr; i++) {
1795                        struct diff_filepair *p = q->queue[i];
1796
1797                        if (((p->status == DIFF_STATUS_MODIFIED) &&
1798                             ((p->score &&
1799                               strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
1800                              (!p->score &&
1801                               strchr(filter, DIFF_STATUS_MODIFIED)))) ||
1802                            ((p->status != DIFF_STATUS_MODIFIED) &&
1803                             strchr(filter, p->status)))
1804                                diff_q(&outq, p);
1805                        else
1806                                diff_free_filepair(p);
1807                }
1808        }
1809        free(q->queue);
1810        *q = outq;
1811}
1812
1813void diffcore_std(struct diff_options *options)
1814{
1815        if (options->break_opt != -1)
1816                diffcore_break(options->break_opt);
1817        if (options->detect_rename)
1818                diffcore_rename(options);
1819        if (options->break_opt != -1)
1820                diffcore_merge_broken();
1821        if (options->pickaxe)
1822                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1823        if (options->orderfile)
1824                diffcore_order(options->orderfile);
1825        diff_resolve_rename_copy();
1826        diffcore_apply_filter(options->filter);
1827}
1828
1829
1830void diffcore_std_no_resolve(struct diff_options *options)
1831{
1832        if (options->pickaxe)
1833                diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
1834        if (options->orderfile)
1835                diffcore_order(options->orderfile);
1836        diffcore_apply_filter(options->filter);
1837}
1838
1839void diff_addremove(struct diff_options *options,
1840                    int addremove, unsigned mode,
1841                    const unsigned char *sha1,
1842                    const char *base, const char *path)
1843{
1844        char concatpath[PATH_MAX];
1845        struct diff_filespec *one, *two;
1846
1847        /* This may look odd, but it is a preparation for
1848         * feeding "there are unchanged files which should
1849         * not produce diffs, but when you are doing copy
1850         * detection you would need them, so here they are"
1851         * entries to the diff-core.  They will be prefixed
1852         * with something like '=' or '*' (I haven't decided
1853         * which but should not make any difference).
1854         * Feeding the same new and old to diff_change() 
1855         * also has the same effect.
1856         * Before the final output happens, they are pruned after
1857         * merged into rename/copy pairs as appropriate.
1858         */
1859        if (options->reverse_diff)
1860                addremove = (addremove == '+' ? '-' :
1861                             addremove == '-' ? '+' : addremove);
1862
1863        if (!path) path = "";
1864        sprintf(concatpath, "%s%s", base, path);
1865        one = alloc_filespec(concatpath);
1866        two = alloc_filespec(concatpath);
1867
1868        if (addremove != '+')
1869                fill_filespec(one, sha1, mode);
1870        if (addremove != '-')
1871                fill_filespec(two, sha1, mode);
1872
1873        diff_queue(&diff_queued_diff, one, two);
1874}
1875
1876void diff_change(struct diff_options *options,
1877                 unsigned old_mode, unsigned new_mode,
1878                 const unsigned char *old_sha1,
1879                 const unsigned char *new_sha1,
1880                 const char *base, const char *path) 
1881{
1882        char concatpath[PATH_MAX];
1883        struct diff_filespec *one, *two;
1884
1885        if (options->reverse_diff) {
1886                unsigned tmp;
1887                const unsigned char *tmp_c;
1888                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
1889                tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
1890        }
1891        if (!path) path = "";
1892        sprintf(concatpath, "%s%s", base, path);
1893        one = alloc_filespec(concatpath);
1894        two = alloc_filespec(concatpath);
1895        fill_filespec(one, old_sha1, old_mode);
1896        fill_filespec(two, new_sha1, new_mode);
1897
1898        diff_queue(&diff_queued_diff, one, two);
1899}
1900
1901void diff_unmerge(struct diff_options *options,
1902                  const char *path)
1903{
1904        struct diff_filespec *one, *two;
1905        one = alloc_filespec(path);
1906        two = alloc_filespec(path);
1907        diff_queue(&diff_queued_diff, one, two);
1908}