setup.c

   1 #include "cache.h"
   2 #include "dir.h"
   3 #include "string-list.h"
   4
   5 static int inside_git_dir = -1;
   6 static int inside_work_tree = -1;
   7
   8 static char *prefix_path_gently(const char *prefix, int len, const char *path)
   9 {
  10         const char *orig = path;
  11         char *sanitized;
  12         if (is_absolute_path(orig)) {
  13                 const char *temp = real_path(path);
  14                 sanitized = xmalloc(len + strlen(temp) + 1);
  15                 strcpy(sanitized, temp);
  16         } else {
  17                 sanitized = xmalloc(len + strlen(path) + 1);
  18                 if (len)
  19                         memcpy(sanitized, prefix, len);
  20                 strcpy(sanitized + len, path);
  21         }
  22         if (normalize_path_copy(sanitized, sanitized))
  23                 goto error_out;
  24         if (is_absolute_path(orig)) {
  25                 size_t root_len, len, total;
  26                 const char *work_tree = get_git_work_tree();
  27                 if (!work_tree)
  28                         goto error_out;
  29                 len = strlen(work_tree);
  30                 root_len = offset_1st_component(work_tree);
  31                 total = strlen(sanitized) + 1;
  32                 if (strncmp(sanitized, work_tree, len) ||
  33                     (len > root_len && sanitized[len] != '\0' && sanitized[len] != '/')) {
  34                 error_out:
  35                         free(sanitized);
  36                         return NULL;
  37                 }
  38                 if (sanitized[len] == '/')
  39                         len++;
  40                 memmove(sanitized, sanitized + len, total - len);
  41         }
  42         return sanitized;
  43 }
  44
  45 char *prefix_path(const char *prefix, int len, const char *path)
  46 {
  47         char *r = prefix_path_gently(prefix, len, path);
  48         if (!r)
  49                 die("'%s' is outside repository", path);
  50         return r;
  51 }
  52
  53 int path_inside_repo(const char *prefix, const char *path)
  54 {
  55         int len = prefix ? strlen(prefix) : 0;
  56         char *r = prefix_path_gently(prefix, len, path);
  57         if (r) {
  58                 free(r);
  59                 return 1;
  60         }
  61         return 0;
  62 }
  63
  64 int check_filename(const char *prefix, const char *arg)
  65 {
  66         const char *name;
  67         struct stat st;
  68
  69         if (!prefixcmp(arg, ":/")) {
  70                 if (arg[2] == '\0') /* ":/" is root dir, always exists */
  71                         return 1;
  72                 name = arg + 2;
  73         } else if (prefix)
  74                 name = prefix_filename(prefix, strlen(prefix), arg);
  75         else
  76                 name = arg;
  77         if (!lstat(name, &st))
  78                 return 1; /* file exists */
  79         if (errno == ENOENT || errno == ENOTDIR)
  80                 return 0; /* file does not exist */
  81         die_errno("failed to stat '%s'", arg);
  82 }
  83
  84 static void NORETURN die_verify_filename(const char *prefix,
  85                                          const char *arg,
  86                                          int diagnose_misspelt_rev)
  87 {
  88         if (!diagnose_misspelt_rev)
  89                 die("%s: no such path in the working tree.\n"
  90                     "Use 'git <command> -- <path>...' to specify paths that do not exist locally.",
  91                     arg);
  92         /*
  93          * Saying "'(icase)foo' does not exist in the index" when the
  94          * user gave us ":(icase)foo" is just stupid.  A magic pathspec
  95          * begins with a colon and is followed by a non-alnum; do not
  96          * let maybe_die_on_misspelt_object_name() even trigger.
  97          */
  98         if (!(arg[0] == ':' && !isalnum(arg[1])))
  99                 maybe_die_on_misspelt_object_name(arg, prefix);
 100
 101         /* ... or fall back the most general message. */
 102         die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
 103             "Use '--' to separate paths from revisions, like this:\n"
 104             "'git <command> [<revision>...] -- [<file>...]'", arg);
 105
 106 }
 107
 108 /*
 109  * Verify a filename that we got as an argument for a pathspec
 110  * entry. Note that a filename that begins with "-" never verifies
 111  * as true, because even if such a filename were to exist, we want
 112  * it to be preceded by the "--" marker (or we want the user to
 113  * use a format like "./-filename")
 114  *
 115  * The "diagnose_misspelt_rev" is used to provide a user-friendly
 116  * diagnosis when dying upon finding that "name" is not a pathname.
 117  * If set to 1, the diagnosis will try to diagnose "name" as an
 118  * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
 119  * will only complain about an inexisting file.
 120  *
 121  * This function is typically called to check that a "file or rev"
 122  * argument is unambiguous. In this case, the caller will want
 123  * diagnose_misspelt_rev == 1 when verifying the first non-rev
 124  * argument (which could have been a revision), and
 125  * diagnose_misspelt_rev == 0 for the next ones (because we already
 126  * saw a filename, there's not ambiguity anymore).
 127  */
 128 void verify_filename(const char *prefix,
 129                      const char *arg,
 130                      int diagnose_misspelt_rev)
 131 {
 132         if (*arg == '-')
 133                 die("bad flag '%s' used after filename", arg);
 134         if (check_filename(prefix, arg))
 135                 return;
 136         die_verify_filename(prefix, arg, diagnose_misspelt_rev);
 137 }
 138
 139 /*
 140  * Opposite of the above: the command line did not have -- marker
 141  * and we parsed the arg as a refname.  It should not be interpretable
 142  * as a filename.
 143  */
 144 void verify_non_filename(const char *prefix, const char *arg)
 145 {
 146         if (!is_inside_work_tree() || is_inside_git_dir())
 147                 return;
 148         if (*arg == '-')
 149                 return; /* flag */
 150         if (!check_filename(prefix, arg))
 151                 return;
 152         die("ambiguous argument '%s': both revision and filename\n"
 153             "Use '--' to separate paths from revisions, like this:\n"
 154             "'git <command> [<revision>...] -- [<file>...]'", arg);
 155 }
 156
 157 /*
 158  * Magic pathspec
 159  *
 160  * NEEDSWORK: These need to be moved to dir.h or even to a new
 161  * pathspec.h when we restructure get_pathspec() users to use the
 162  * "struct pathspec" interface.
 163  *
 164  * Possible future magic semantics include stuff like:
 165  *
 166  *      { PATHSPEC_NOGLOB, '!', "noglob" },
 167  *      { PATHSPEC_ICASE, '\0', "icase" },
 168  *      { PATHSPEC_RECURSIVE, '*', "recursive" },
 169  *      { PATHSPEC_REGEXP, '\0', "regexp" },
 170  *
 171  */
 172 #define PATHSPEC_FROMTOP    (1<<0)
 173
 174 static struct pathspec_magic {
 175         unsigned bit;
 176         char mnemonic; /* this cannot be ':'! */
 177         const char *name;
 178 } pathspec_magic[] = {
 179         { PATHSPEC_FROMTOP, '/', "top" },
 180 };
 181
 182 /*
 183  * Take an element of a pathspec and check for magic signatures.
 184  * Append the result to the prefix.
 185  *
 186  * For now, we only parse the syntax and throw out anything other than
 187  * "top" magic.
 188  *
 189  * NEEDSWORK: This needs to be rewritten when we start migrating
 190  * get_pathspec() users to use the "struct pathspec" interface.  For
 191  * example, a pathspec element may be marked as case-insensitive, but
 192  * the prefix part must always match literally, and a single stupid
 193  * string cannot express such a case.
 194  */
 195 static const char *prefix_pathspec(const char *prefix, int prefixlen, const char *elt)
 196 {
 197         unsigned magic = 0;
 198         const char *copyfrom = elt;
 199         int i;
 200
 201         if (elt[0] != ':') {
 202                 ; /* nothing to do */
 203         } else if (elt[1] == '(') {
 204                 /* longhand */
 205                 const char *nextat;
 206                 for (copyfrom = elt + 2;
 207                      *copyfrom && *copyfrom != ')';
 208                      copyfrom = nextat) {
 209                         size_t len = strcspn(copyfrom, ",)");
 210                         if (copyfrom[len] == ')')
 211                                 nextat = copyfrom + len;
 212                         else
 213                                 nextat = copyfrom + len + 1;
 214                         if (!len)
 215                                 continue;
 216                         for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 217                                 if (strlen(pathspec_magic[i].name) == len &&
 218                                     !strncmp(pathspec_magic[i].name, copyfrom, len)) {
 219                                         magic |= pathspec_magic[i].bit;
 220                                         break;
 221                                 }
 222                         if (ARRAY_SIZE(pathspec_magic) <= i)
 223                                 die("Invalid pathspec magic '%.*s' in '%s'",
 224                                     (int) len, copyfrom, elt);
 225                 }
 226                 if (*copyfrom == ')')
 227                         copyfrom++;
 228         } else {
 229                 /* shorthand */
 230                 for (copyfrom = elt + 1;
 231                      *copyfrom && *copyfrom != ':';
 232                      copyfrom++) {
 233                         char ch = *copyfrom;
 234
 235                         if (!is_pathspec_magic(ch))
 236                                 break;
 237                         for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 238                                 if (pathspec_magic[i].mnemonic == ch) {
 239                                         magic |= pathspec_magic[i].bit;
 240                                         break;
 241                                 }
 242                         if (ARRAY_SIZE(pathspec_magic) <= i)
 243                                 die("Unimplemented pathspec magic '%c' in '%s'",
 244                                     ch, elt);
 245                 }
 246                 if (*copyfrom == ':')
 247                         copyfrom++;
 248         }
 249
 250         if (magic & PATHSPEC_FROMTOP)
 251                 return xstrdup(copyfrom);
 252         else
 253                 return prefix_path(prefix, prefixlen, copyfrom);
 254 }
 255
 256 /*
 257  * N.B. get_pathspec() is deprecated in favor of the "struct pathspec"
 258  * based interface - see pathspec_magic above.
 259  *
 260  * Arguments:
 261  *  - prefix - a path relative to the root of the working tree
 262  *  - pathspec - a list of paths underneath the prefix path
 263  *
 264  * Iterates over pathspec, prepending each path with prefix,
 265  * and return the resulting list.
 266  *
 267  * If pathspec is empty, return a singleton list containing prefix.
 268  *
 269  * If pathspec and prefix are both empty, return an empty list.
 270  *
 271  * This is typically used by built-in commands such as add.c, in order
 272  * to normalize argv arguments provided to the built-in into a list of
 273  * paths to process, all relative to the root of the working tree.
 274  */
 275 const char **get_pathspec(const char *prefix, const char **pathspec)
 276 {
 277         const char *entry = *pathspec;
 278         const char **src, **dst;
 279         int prefixlen;
 280
 281         if (!prefix && !entry)
 282                 return NULL;
 283
 284         if (!entry) {
 285                 static const char *spec[2];
 286                 spec[0] = prefix;
 287                 spec[1] = NULL;
 288                 return spec;
 289         }
 290
 291         /* Otherwise we have to re-write the entries.. */
 292         src = pathspec;
 293         dst = pathspec;
 294         prefixlen = prefix ? strlen(prefix) : 0;
 295         while (*src) {
 296                 *(dst++) = prefix_pathspec(prefix, prefixlen, *src);
 297                 src++;
 298         }
 299         *dst = NULL;
 300         if (!*pathspec)
 301                 return NULL;
 302         return pathspec;
 303 }
 304
 305 /*
 306  * Test if it looks like we're at a git directory.
 307  * We want to see:
 308  *
 309  *  - either an objects/ directory _or_ the proper
 310  *    GIT_OBJECT_DIRECTORY environment variable
 311  *  - a refs/ directory
 312  *  - either a HEAD symlink or a HEAD file that is formatted as
 313  *    a proper "ref:", or a regular file HEAD that has a properly
 314  *    formatted sha1 object name.
 315  */
 316 int is_git_directory(const char *suspect)
 317 {
 318         char path[PATH_MAX];
 319         size_t len = strlen(suspect);
 320
 321         if (PATH_MAX <= len + strlen("/objects"))
 322                 die("Too long path: %.*s", 60, suspect);
 323         strcpy(path, suspect);
 324         if (getenv(DB_ENVIRONMENT)) {
 325                 if (access(getenv(DB_ENVIRONMENT), X_OK))
 326                         return 0;
 327         }
 328         else {
 329                 strcpy(path + len, "/objects");
 330                 if (access(path, X_OK))
 331                         return 0;
 332         }
 333
 334         strcpy(path + len, "/refs");
 335         if (access(path, X_OK))
 336                 return 0;
 337
 338         strcpy(path + len, "/HEAD");
 339         if (validate_headref(path))
 340                 return 0;
 341
 342         return 1;
 343 }
 344
 345 int is_inside_git_dir(void)
 346 {
 347         if (inside_git_dir < 0)
 348                 inside_git_dir = is_inside_dir(get_git_dir());
 349         return inside_git_dir;
 350 }
 351
 352 int is_inside_work_tree(void)
 353 {
 354         if (inside_work_tree < 0)
 355                 inside_work_tree = is_inside_dir(get_git_work_tree());
 356         return inside_work_tree;
 357 }
 358
 359 void setup_work_tree(void)
 360 {
 361         const char *work_tree, *git_dir;
 362         static int initialized = 0;
 363
 364         if (initialized)
 365                 return;
 366         work_tree = get_git_work_tree();
 367         git_dir = get_git_dir();
 368         if (!is_absolute_path(git_dir))
 369                 git_dir = real_path(get_git_dir());
 370         if (!work_tree || chdir(work_tree))
 371                 die("This operation must be run in a work tree");
 372
 373         /*
 374          * Make sure subsequent git processes find correct worktree
 375          * if $GIT_WORK_TREE is set relative
 376          */
 377         if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 378                 setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 379
 380         set_git_dir(relative_path(git_dir, work_tree));
 381         initialized = 1;
 382 }
 383
 384 static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 385 {
 386         char repo_config[PATH_MAX+1];
 387
 388         /*
 389          * git_config() can't be used here because it calls git_pathdup()
 390          * to get $GIT_CONFIG/config. That call will make setup_git_env()
 391          * set git_dir to ".git".
 392          *
 393          * We are in gitdir setup, no git dir has been found useable yet.
 394          * Use a gentler version of git_config() to check if this repo
 395          * is a good one.
 396          */
 397         snprintf(repo_config, PATH_MAX, "%s/config", gitdir);
 398         git_config_early(check_repository_format_version, NULL, repo_config);
 399         if (GIT_REPO_VERSION < repository_format_version) {
 400                 if (!nongit_ok)
 401                         die ("Expected git repo version <= %d, found %d",
 402                              GIT_REPO_VERSION, repository_format_version);
 403                 warning("Expected git repo version <= %d, found %d",
 404                         GIT_REPO_VERSION, repository_format_version);
 405                 warning("Please upgrade Git");
 406                 *nongit_ok = -1;
 407                 return -1;
 408         }
 409         return 0;
 410 }
 411
 412 /*
 413  * Try to read the location of the git directory from the .git file,
 414  * return path to git directory if found.
 415  */
 416 const char *read_gitfile(const char *path)
 417 {
 418         char *buf;
 419         char *dir;
 420         const char *slash;
 421         struct stat st;
 422         int fd;
 423         ssize_t len;
 424
 425         if (stat(path, &st))
 426                 return NULL;
 427         if (!S_ISREG(st.st_mode))
 428                 return NULL;
 429         fd = open(path, O_RDONLY);
 430         if (fd < 0)
 431                 die_errno("Error opening '%s'", path);
 432         buf = xmalloc(st.st_size + 1);
 433         len = read_in_full(fd, buf, st.st_size);
 434         close(fd);
 435         if (len != st.st_size)
 436                 die("Error reading %s", path);
 437         buf[len] = '\0';
 438         if (prefixcmp(buf, "gitdir: "))
 439                 die("Invalid gitfile format: %s", path);
 440         while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 441                 len--;
 442         if (len < 9)
 443                 die("No path in gitfile: %s", path);
 444         buf[len] = '\0';
 445         dir = buf + 8;
 446
 447         if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 448                 size_t pathlen = slash+1 - path;
 449                 size_t dirlen = pathlen + len - 8;
 450                 dir = xmalloc(dirlen + 1);
 451                 strncpy(dir, path, pathlen);
 452                 strncpy(dir + pathlen, buf + 8, len - 8);
 453                 dir[dirlen] = '\0';
 454                 free(buf);
 455                 buf = dir;
 456         }
 457
 458         if (!is_git_directory(dir))
 459                 die("Not a git repository: %s", dir);
 460         path = real_path(dir);
 461
 462         free(buf);
 463         return path;
 464 }
 465
 466 static const char *setup_explicit_git_dir(const char *gitdirenv,
 467                                           char *cwd, int len,
 468                                           int *nongit_ok)
 469 {
 470         const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 471         const char *worktree;
 472         char *gitfile;
 473         int offset;
 474
 475         if (PATH_MAX - 40 < strlen(gitdirenv))
 476                 die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 477
 478         gitfile = (char*)read_gitfile(gitdirenv);
 479         if (gitfile) {
 480                 gitfile = xstrdup(gitfile);
 481                 gitdirenv = gitfile;
 482         }
 483
 484         if (!is_git_directory(gitdirenv)) {
 485                 if (nongit_ok) {
 486                         *nongit_ok = 1;
 487                         free(gitfile);
 488                         return NULL;
 489                 }
 490                 die("Not a git repository: '%s'", gitdirenv);
 491         }
 492
 493         if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 494                 free(gitfile);
 495                 return NULL;
 496         }
 497
 498         /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 499         if (work_tree_env)
 500                 set_git_work_tree(work_tree_env);
 501         else if (is_bare_repository_cfg > 0) {
 502                 if (git_work_tree_cfg) /* #22.2, #30 */
 503                         die("core.bare and core.worktree do not make sense");
 504
 505                 /* #18, #26 */
 506                 set_git_dir(gitdirenv);
 507                 free(gitfile);
 508                 return NULL;
 509         }
 510         else if (git_work_tree_cfg) { /* #6, #14 */
 511                 if (is_absolute_path(git_work_tree_cfg))
 512                         set_git_work_tree(git_work_tree_cfg);
 513                 else {
 514                         char core_worktree[PATH_MAX];
 515                         if (chdir(gitdirenv))
 516                                 die_errno("Could not chdir to '%s'", gitdirenv);
 517                         if (chdir(git_work_tree_cfg))
 518                                 die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 519                         if (!getcwd(core_worktree, PATH_MAX))
 520                                 die_errno("Could not get directory '%s'", git_work_tree_cfg);
 521                         if (chdir(cwd))
 522                                 die_errno("Could not come back to cwd");
 523                         set_git_work_tree(core_worktree);
 524                 }
 525         }
 526         else /* #2, #10 */
 527                 set_git_work_tree(".");
 528
 529         /* set_git_work_tree() must have been called by now */
 530         worktree = get_git_work_tree();
 531
 532         /* both get_git_work_tree() and cwd are already normalized */
 533         if (!strcmp(cwd, worktree)) { /* cwd == worktree */
 534                 set_git_dir(gitdirenv);
 535                 free(gitfile);
 536                 return NULL;
 537         }
 538
 539         offset = dir_inside_of(cwd, worktree);
 540         if (offset >= 0) {      /* cwd inside worktree? */
 541                 set_git_dir(real_path(gitdirenv));
 542                 if (chdir(worktree))
 543                         die_errno("Could not chdir to '%s'", worktree);
 544                 cwd[len++] = '/';
 545                 cwd[len] = '\0';
 546                 free(gitfile);
 547                 return cwd + offset;
 548         }
 549
 550         /* cwd outside worktree */
 551         set_git_dir(gitdirenv);
 552         free(gitfile);
 553         return NULL;
 554 }
 555
 556 static const char *setup_discovered_git_dir(const char *gitdir,
 557                                             char *cwd, int offset, int len,
 558                                             int *nongit_ok)
 559 {
 560         if (check_repository_format_gently(gitdir, nongit_ok))
 561                 return NULL;
 562
 563         /* --work-tree is set without --git-dir; use discovered one */
 564         if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 565                 if (offset != len && !is_absolute_path(gitdir))
 566                         gitdir = xstrdup(real_path(gitdir));
 567                 if (chdir(cwd))
 568                         die_errno("Could not come back to cwd");
 569                 return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
 570         }
 571
 572         /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 573         if (is_bare_repository_cfg > 0) {
 574                 set_git_dir(offset == len ? gitdir : real_path(gitdir));
 575                 if (chdir(cwd))
 576                         die_errno("Could not come back to cwd");
 577                 return NULL;
 578         }
 579
 580         /* #0, #1, #5, #8, #9, #12, #13 */
 581         set_git_work_tree(".");
 582         if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 583                 set_git_dir(gitdir);
 584         inside_git_dir = 0;
 585         inside_work_tree = 1;
 586         if (offset == len)
 587                 return NULL;
 588
 589         /* Make "offset" point to past the '/', and add a '/' at the end */
 590         offset++;
 591         cwd[len++] = '/';
 592         cwd[len] = 0;
 593         return cwd + offset;
 594 }
 595
 596 /* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 597 static const char *setup_bare_git_dir(char *cwd, int offset, int len, int *nongit_ok)
 598 {
 599         int root_len;
 600
 601         if (check_repository_format_gently(".", nongit_ok))
 602                 return NULL;
 603
 604         /* --work-tree is set without --git-dir; use discovered one */
 605         if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 606                 const char *gitdir;
 607
 608                 gitdir = offset == len ? "." : xmemdupz(cwd, offset);
 609                 if (chdir(cwd))
 610                         die_errno("Could not come back to cwd");
 611                 return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
 612         }
 613
 614         inside_git_dir = 1;
 615         inside_work_tree = 0;
 616         if (offset != len) {
 617                 if (chdir(cwd))
 618                         die_errno("Cannot come back to cwd");
 619                 root_len = offset_1st_component(cwd);
 620                 cwd[offset > root_len ? offset : root_len] = '\0';
 621                 set_git_dir(cwd);
 622         }
 623         else
 624                 set_git_dir(".");
 625         return NULL;
 626 }
 627
 628 static const char *setup_nongit(const char *cwd, int *nongit_ok)
 629 {
 630         if (!nongit_ok)
 631                 die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
 632         if (chdir(cwd))
 633                 die_errno("Cannot come back to cwd");
 634         *nongit_ok = 1;
 635         return NULL;
 636 }
 637
 638 static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 639 {
 640         struct stat buf;
 641         if (stat(path, &buf)) {
 642                 die_errno("failed to stat '%*s%s%s'",
 643                                 prefix_len,
 644                                 prefix ? prefix : "",
 645                                 prefix ? "/" : "", path);
 646         }
 647         return buf.st_dev;
 648 }
 649
 650 /*
 651  * A "string_list_each_func_t" function that canonicalizes an entry
 652  * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
 653  * discards it if unusable.  The presence of an empty entry in
 654  * GIT_CEILING_DIRECTORIES turns off canonicalization for all
 655  * subsequent entries.
 656  */
 657 static int canonicalize_ceiling_entry(struct string_list_item *item,
 658                                       void *cb_data)
 659 {
 660         int *empty_entry_found = cb_data;
 661         char *ceil = item->string;
 662
 663         if (!*ceil) {
 664                 *empty_entry_found = 1;
 665                 return 0;
 666         } else if (!is_absolute_path(ceil)) {
 667                 return 0;
 668         } else if (*empty_entry_found) {
 669                 /* Keep entry but do not canonicalize it */
 670                 return 1;
 671         } else {
 672                 const char *real_path = real_path_if_valid(ceil);
 673                 if (!real_path)
 674                         return 0;
 675                 free(item->string);
 676                 item->string = xstrdup(real_path);
 677                 return 1;
 678         }
 679 }
 680
 681 /*
 682  * We cannot decide in this function whether we are in the work tree or
 683  * not, since the config can only be read _after_ this function was called.
 684  */
 685 static const char *setup_git_directory_gently_1(int *nongit_ok)
 686 {
 687         const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 688         struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
 689         static char cwd[PATH_MAX+1];
 690         const char *gitdirenv, *ret;
 691         char *gitfile;
 692         int len, offset, offset_parent, ceil_offset = -1;
 693         dev_t current_device = 0;
 694         int one_filesystem = 1;
 695
 696         /*
 697          * Let's assume that we are in a git repository.
 698          * If it turns out later that we are somewhere else, the value will be
 699          * updated accordingly.
 700          */
 701         if (nongit_ok)
 702                 *nongit_ok = 0;
 703
 704         if (!getcwd(cwd, sizeof(cwd)-1))
 705                 die_errno("Unable to read current working directory");
 706         offset = len = strlen(cwd);
 707
 708         /*
 709          * If GIT_DIR is set explicitly, we're not going
 710          * to do any discovery, but we still do repository
 711          * validation.
 712          */
 713         gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 714         if (gitdirenv)
 715                 return setup_explicit_git_dir(gitdirenv, cwd, len, nongit_ok);
 716
 717         if (env_ceiling_dirs) {
 718                 int empty_entry_found = 0;
 719
 720                 string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
 721                 filter_string_list(&ceiling_dirs, 0,
 722                                    canonicalize_ceiling_entry, &empty_entry_found);
 723                 ceil_offset = longest_ancestor_length(cwd, &ceiling_dirs);
 724                 string_list_clear(&ceiling_dirs, 0);
 725         }
 726
 727         if (ceil_offset < 0 && has_dos_drive_prefix(cwd))
 728                 ceil_offset = 1;
 729
 730         /*
 731          * Test in the following order (relative to the cwd):
 732          * - .git (file containing "gitdir: <path>")
 733          * - .git/
 734          * - ./ (bare)
 735          * - ../.git
 736          * - ../.git/
 737          * - ../ (bare)
 738          * - ../../.git/
 739          *   etc.
 740          */
 741         one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 742         if (one_filesystem)
 743                 current_device = get_device_or_die(".", NULL, 0);
 744         for (;;) {
 745                 gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
 746                 if (gitfile)
 747                         gitdirenv = gitfile = xstrdup(gitfile);
 748                 else {
 749                         if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 750                                 gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 751                 }
 752
 753                 if (gitdirenv) {
 754                         ret = setup_discovered_git_dir(gitdirenv,
 755                                                        cwd, offset, len,
 756                                                        nongit_ok);
 757                         free(gitfile);
 758                         return ret;
 759                 }
 760                 free(gitfile);
 761
 762                 if (is_git_directory("."))
 763                         return setup_bare_git_dir(cwd, offset, len, nongit_ok);
 764
 765                 offset_parent = offset;
 766                 while (--offset_parent > ceil_offset && cwd[offset_parent] != '/');
 767                 if (offset_parent <= ceil_offset)
 768                         return setup_nongit(cwd, nongit_ok);
 769                 if (one_filesystem) {
 770                         dev_t parent_device = get_device_or_die("..", cwd, offset);
 771                         if (parent_device != current_device) {
 772                                 if (nongit_ok) {
 773                                         if (chdir(cwd))
 774                                                 die_errno("Cannot come back to cwd");
 775                                         *nongit_ok = 1;
 776                                         return NULL;
 777                                 }
 778                                 cwd[offset] = '\0';
 779                                 die("Not a git repository (or any parent up to mount point %s)\n"
 780                                 "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).", cwd);
 781                         }
 782                 }
 783                 if (chdir("..")) {
 784                         cwd[offset] = '\0';
 785                         die_errno("Cannot change to '%s/..'", cwd);
 786                 }
 787                 offset = offset_parent;
 788         }
 789 }
 790
 791 const char *setup_git_directory_gently(int *nongit_ok)
 792 {
 793         const char *prefix;
 794
 795         prefix = setup_git_directory_gently_1(nongit_ok);
 796         if (prefix)
 797                 setenv("GIT_PREFIX", prefix, 1);
 798         else
 799                 setenv("GIT_PREFIX", "", 1);
 800
 801         if (startup_info) {
 802                 startup_info->have_repository = !nongit_ok || !*nongit_ok;
 803                 startup_info->prefix = prefix;
 804         }
 805         return prefix;
 806 }
 807
 808 int git_config_perm(const char *var, const char *value)
 809 {
 810         int i;
 811         char *endptr;
 812
 813         if (value == NULL)
 814                 return PERM_GROUP;
 815
 816         if (!strcmp(value, "umask"))
 817                 return PERM_UMASK;
 818         if (!strcmp(value, "group"))
 819                 return PERM_GROUP;
 820         if (!strcmp(value, "all") ||
 821             !strcmp(value, "world") ||
 822             !strcmp(value, "everybody"))
 823                 return PERM_EVERYBODY;
 824
 825         /* Parse octal numbers */
 826         i = strtol(value, &endptr, 8);
 827
 828         /* If not an octal number, maybe true/false? */
 829         if (*endptr != 0)
 830                 return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 831
 832         /*
 833          * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 834          * a chmod value to restrict to.
 835          */
 836         switch (i) {
 837         case PERM_UMASK:               /* 0 */
 838                 return PERM_UMASK;
 839         case OLD_PERM_GROUP:           /* 1 */
 840                 return PERM_GROUP;
 841         case OLD_PERM_EVERYBODY:       /* 2 */
 842                 return PERM_EVERYBODY;
 843         }
 844
 845         /* A filemode value was given: 0xxx */
 846
 847         if ((i & 0600) != 0600)
 848                 die("Problem with core.sharedRepository filemode value "
 849                     "(0%.3o).\nThe owner of files must always have "
 850                     "read and write permissions.", i);
 851
 852         /*
 853          * Mask filemode value. Others can not get write permission.
 854          * x flags for directories are handled separately.
 855          */
 856         return -(i & 0666);
 857 }
 858
 859 int check_repository_format_version(const char *var, const char *value, void *cb)
 860 {
 861         if (strcmp(var, "core.repositoryformatversion") == 0)
 862                 repository_format_version = git_config_int(var, value);
 863         else if (strcmp(var, "core.sharedrepository") == 0)
 864                 shared_repository = git_config_perm(var, value);
 865         else if (strcmp(var, "core.bare") == 0) {
 866                 is_bare_repository_cfg = git_config_bool(var, value);
 867                 if (is_bare_repository_cfg == 1)
 868                         inside_work_tree = -1;
 869         } else if (strcmp(var, "core.worktree") == 0) {
 870                 if (!value)
 871                         return config_error_nonbool(var);
 872                 free(git_work_tree_cfg);
 873                 git_work_tree_cfg = xstrdup(value);
 874                 inside_work_tree = -1;
 875         }
 876         return 0;
 877 }
 878
 879 int check_repository_format(void)
 880 {
 881         return check_repository_format_gently(get_git_dir(), NULL);
 882 }
 883
 884 /*
 885  * Returns the "prefix", a path to the current working directory
 886  * relative to the work tree root, or NULL, if the current working
 887  * directory is not a strict subdirectory of the work tree root. The
 888  * prefix always ends with a '/' character.
 889  */
 890 const char *setup_git_directory(void)
 891 {
 892         return setup_git_directory_gently(NULL);
 893 }
 894
 895 const char *resolve_gitdir(const char *suspect)
 896 {
 897         if (is_git_directory(suspect))
 898                 return suspect;
 899         return read_gitfile(suspect);
 900 }