diff options
Diffstat (limited to 'third_party/git/setup.c')
| -rw-r--r-- | third_party/git/setup.c | 1320 |
1 files changed, 1320 insertions, 0 deletions
diff --git a/third_party/git/setup.c b/third_party/git/setup.c new file mode 100644 index 000000000000..5ea9285a128c --- /dev/null +++ b/third_party/git/setup.c @@ -0,0 +1,1320 @@ +#include "cache.h" +#include "repository.h" +#include "config.h" +#include "dir.h" +#include "string-list.h" +#include "chdir-notify.h" +#include "promisor-remote.h" + +static int inside_git_dir = -1; +static int inside_work_tree = -1; +static int work_tree_config_is_bogus; + +static struct startup_info the_startup_info; +struct startup_info *startup_info = &the_startup_info; + +/* + * The input parameter must contain an absolute path, and it must already be + * normalized. + * + * Find the part of an absolute path that lies inside the work tree by + * dereferencing symlinks outside the work tree, for example: + * /dir1/repo/dir2/file (work tree is /dir1/repo) -> dir2/file + * /dir/file (work tree is /) -> dir/file + * /dir/symlink1/symlink2 (symlink1 points to work tree) -> symlink2 + * /dir/repolink/file (repolink points to /dir/repo) -> file + * /dir/repo (exactly equal to work tree) -> (empty string) + */ +static int abspath_part_inside_repo(char *path) +{ + size_t len; + size_t wtlen; + char *path0; + int off; + const char *work_tree = get_git_work_tree(); + + if (!work_tree) + return -1; + wtlen = strlen(work_tree); + len = strlen(path); + off = offset_1st_component(path); + + /* check if work tree is already the prefix */ + if (wtlen <= len && !fspathncmp(path, work_tree, wtlen)) { + if (path[wtlen] == '/') { + memmove(path, path + wtlen + 1, len - wtlen); + return 0; + } else if (path[wtlen - 1] == '/' || path[wtlen] == '\0') { + /* work tree is the root, or the whole path */ + memmove(path, path + wtlen, len - wtlen + 1); + return 0; + } + /* work tree might match beginning of a symlink to work tree */ + off = wtlen; + } + path0 = path; + path += off; + + /* check each '/'-terminated level */ + while (*path) { + path++; + if (*path == '/') { + *path = '\0'; + if (fspathcmp(real_path(path0), work_tree) == 0) { + memmove(path0, path + 1, len - (path - path0)); + return 0; + } + *path = '/'; + } + } + + /* check whole path */ + if (fspathcmp(real_path(path0), work_tree) == 0) { + *path0 = '\0'; + return 0; + } + + return -1; +} + +/* + * Normalize "path", prepending the "prefix" for relative paths. If + * remaining_prefix is not NULL, return the actual prefix still + * remains in the path. For example, prefix = sub1/sub2/ and path is + * + * foo -> sub1/sub2/foo (full prefix) + * ../foo -> sub1/foo (remaining prefix is sub1/) + * ../../bar -> bar (no remaining prefix) + * ../../sub1/sub2/foo -> sub1/sub2/foo (but no remaining prefix) + * `pwd`/../bar -> sub1/bar (no remaining prefix) + */ +char *prefix_path_gently(const char *prefix, int len, + int *remaining_prefix, const char *path) +{ + const char *orig = path; + char *sanitized; + if (is_absolute_path(orig)) { + sanitized = xmallocz(strlen(path)); + if (remaining_prefix) + *remaining_prefix = 0; + if (normalize_path_copy_len(sanitized, path, remaining_prefix)) { + free(sanitized); + return NULL; + } + if (abspath_part_inside_repo(sanitized)) { + free(sanitized); + return NULL; + } + } else { + sanitized = xstrfmt("%.*s%s", len, len ? prefix : "", path); + if (remaining_prefix) + *remaining_prefix = len; + if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) { + free(sanitized); + return NULL; + } + } + return sanitized; +} + +char *prefix_path(const char *prefix, int len, const char *path) +{ + char *r = prefix_path_gently(prefix, len, NULL, path); + if (!r) { + const char *hint_path = get_git_work_tree(); + if (!hint_path) + hint_path = get_git_dir(); + die(_("'%s' is outside repository at '%s'"), path, + absolute_path(hint_path)); + } + return r; +} + +int path_inside_repo(const char *prefix, const char *path) +{ + int len = prefix ? strlen(prefix) : 0; + char *r = prefix_path_gently(prefix, len, NULL, path); + if (r) { + free(r); + return 1; + } + return 0; +} + +int check_filename(const char *prefix, const char *arg) +{ + char *to_free = NULL; + struct stat st; + + if (skip_prefix(arg, ":/", &arg)) { + if (!*arg) /* ":/" is root dir, always exists */ + return 1; + prefix = NULL; + } else if (skip_prefix(arg, ":!", &arg) || + skip_prefix(arg, ":^", &arg)) { + if (!*arg) /* excluding everything is silly, but allowed */ + return 1; + } + + if (prefix) + arg = to_free = prefix_filename(prefix, arg); + + if (!lstat(arg, &st)) { + free(to_free); + return 1; /* file exists */ + } + if (is_missing_file_error(errno)) { + free(to_free); + return 0; /* file does not exist */ + } + die_errno(_("failed to stat '%s'"), arg); +} + +static void NORETURN die_verify_filename(struct repository *r, + const char *prefix, + const char *arg, + int diagnose_misspelt_rev) +{ + if (!diagnose_misspelt_rev) + die(_("%s: no such path in the working tree.\n" + "Use 'git <command> -- <path>...' to specify paths that do not exist locally."), + arg); + /* + * Saying "'(icase)foo' does not exist in the index" when the + * user gave us ":(icase)foo" is just stupid. A magic pathspec + * begins with a colon and is followed by a non-alnum; do not + * let maybe_die_on_misspelt_object_name() even trigger. + */ + if (!(arg[0] == ':' && !isalnum(arg[1]))) + maybe_die_on_misspelt_object_name(r, arg, prefix); + + /* ... or fall back the most general message. */ + die(_("ambiguous argument '%s': unknown revision or path not in the working tree.\n" + "Use '--' to separate paths from revisions, like this:\n" + "'git <command> [<revision>...] -- [<file>...]'"), arg); + +} + +/* + * Check for arguments that don't resolve as actual files, + * but which look sufficiently like pathspecs that we'll consider + * them such for the purposes of rev/pathspec DWIM parsing. + */ +static int looks_like_pathspec(const char *arg) +{ + const char *p; + int escaped = 0; + + /* + * Wildcard characters imply the user is looking to match pathspecs + * that aren't in the filesystem. Note that this doesn't include + * backslash even though it's a glob special; by itself it doesn't + * cause any increase in the match. Likewise ignore backslash-escaped + * wildcard characters. + */ + for (p = arg; *p; p++) { + if (escaped) { + escaped = 0; + } else if (is_glob_special(*p)) { + if (*p == '\\') + escaped = 1; + else + return 1; + } + } + + /* long-form pathspec magic */ + if (starts_with(arg, ":(")) + return 1; + + return 0; +} + +/* + * Verify a filename that we got as an argument for a pathspec + * entry. Note that a filename that begins with "-" never verifies + * as true, because even if such a filename were to exist, we want + * it to be preceded by the "--" marker (or we want the user to + * use a format like "./-filename") + * + * The "diagnose_misspelt_rev" is used to provide a user-friendly + * diagnosis when dying upon finding that "name" is not a pathname. + * If set to 1, the diagnosis will try to diagnose "name" as an + * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis + * will only complain about an inexisting file. + * + * This function is typically called to check that a "file or rev" + * argument is unambiguous. In this case, the caller will want + * diagnose_misspelt_rev == 1 when verifying the first non-rev + * argument (which could have been a revision), and + * diagnose_misspelt_rev == 0 for the next ones (because we already + * saw a filename, there's not ambiguity anymore). + */ +void verify_filename(const char *prefix, + const char *arg, + int diagnose_misspelt_rev) +{ + if (*arg == '-') + die(_("option '%s' must come before non-option arguments"), arg); + if (looks_like_pathspec(arg) || check_filename(prefix, arg)) + return; + die_verify_filename(the_repository, prefix, arg, diagnose_misspelt_rev); +} + +/* + * Opposite of the above: the command line did not have -- marker + * and we parsed the arg as a refname. It should not be interpretable + * as a filename. + */ +void verify_non_filename(const char *prefix, const char *arg) +{ + if (!is_inside_work_tree() || is_inside_git_dir()) + return; + if (*arg == '-') + return; /* flag */ + if (!check_filename(prefix, arg)) + return; + die(_("ambiguous argument '%s': both revision and filename\n" + "Use '--' to separate paths from revisions, like this:\n" + "'git <command> [<revision>...] -- [<file>...]'"), arg); +} + +int get_common_dir(struct strbuf *sb, const char *gitdir) +{ + const char *git_env_common_dir = getenv(GIT_COMMON_DIR_ENVIRONMENT); + if (git_env_common_dir) { + strbuf_addstr(sb, git_env_common_dir); + return 1; + } else { + return get_common_dir_noenv(sb, gitdir); + } +} + +int get_common_dir_noenv(struct strbuf *sb, const char *gitdir) +{ + struct strbuf data = STRBUF_INIT; + struct strbuf path = STRBUF_INIT; + int ret = 0; + + strbuf_addf(&path, "%s/commondir", gitdir); + if (file_exists(path.buf)) { + if (strbuf_read_file(&data, path.buf, 0) <= 0) + die_errno(_("failed to read %s"), path.buf); + while (data.len && (data.buf[data.len - 1] == '\n' || + data.buf[data.len - 1] == '\r')) + data.len--; + data.buf[data.len] = '\0'; + strbuf_reset(&path); + if (!is_absolute_path(data.buf)) + strbuf_addf(&path, "%s/", gitdir); + strbuf_addbuf(&path, &data); + strbuf_add_real_path(sb, path.buf); + ret = 1; + } else { + strbuf_addstr(sb, gitdir); + } + + strbuf_release(&data); + strbuf_release(&path); + return ret; +} + +/* + * Test if it looks like we're at a git directory. + * We want to see: + * + * - either an objects/ directory _or_ the proper + * GIT_OBJECT_DIRECTORY environment variable + * - a refs/ directory + * - either a HEAD symlink or a HEAD file that is formatted as + * a proper "ref:", or a regular file HEAD that has a properly + * formatted sha1 object name. + */ +int is_git_directory(const char *suspect) +{ + struct strbuf path = STRBUF_INIT; + int ret = 0; + size_t len; + + /* Check worktree-related signatures */ + strbuf_addstr(&path, suspect); + strbuf_complete(&path, '/'); + strbuf_addstr(&path, "HEAD"); + if (validate_headref(path.buf)) + goto done; + + strbuf_reset(&path); + get_common_dir(&path, suspect); + len = path.len; + + /* Check non-worktree-related signatures */ + if (getenv(DB_ENVIRONMENT)) { + if (access(getenv(DB_ENVIRONMENT), X_OK)) + goto done; + } + else { + strbuf_setlen(&path, len); + strbuf_addstr(&path, "/objects"); + if (access(path.buf, X_OK)) + goto done; + } + + strbuf_setlen(&path, len); + strbuf_addstr(&path, "/refs"); + if (access(path.buf, X_OK)) + goto done; + + ret = 1; +done: + strbuf_release(&path); + return ret; +} + +int is_nonbare_repository_dir(struct strbuf *path) +{ + int ret = 0; + int gitfile_error; + size_t orig_path_len = path->len; + assert(orig_path_len != 0); + strbuf_complete(path, '/'); + strbuf_addstr(path, ".git"); + if (read_gitfile_gently(path->buf, &gitfile_error) || is_git_directory(path->buf)) + ret = 1; + if (gitfile_error == READ_GITFILE_ERR_OPEN_FAILED || + gitfile_error == READ_GITFILE_ERR_READ_FAILED) + ret = 1; + strbuf_setlen(path, orig_path_len); + return ret; +} + +int is_inside_git_dir(void) +{ + if (inside_git_dir < 0) + inside_git_dir = is_inside_dir(get_git_dir()); + return inside_git_dir; +} + +int is_inside_work_tree(void) +{ + if (inside_work_tree < 0) + inside_work_tree = is_inside_dir(get_git_work_tree()); + return inside_work_tree; +} + +void setup_work_tree(void) +{ + const char *work_tree; + static int initialized = 0; + + if (initialized) + return; + + if (work_tree_config_is_bogus) + die(_("unable to set up work tree using invalid config")); + + work_tree = get_git_work_tree(); + if (!work_tree || chdir_notify(work_tree)) + die(_("this operation must be run in a work tree")); + + /* + * Make sure subsequent git processes find correct worktree + * if $GIT_WORK_TREE is set relative + */ + if (getenv(GIT_WORK_TREE_ENVIRONMENT)) + setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1); + + initialized = 1; +} + +static int read_worktree_config(const char *var, const char *value, void *vdata) +{ + struct repository_format *data = vdata; + + if (strcmp(var, "core.bare") == 0) { + data->is_bare = git_config_bool(var, value); + } else if (strcmp(var, "core.worktree") == 0) { + if (!value) + return config_error_nonbool(var); + free(data->work_tree); + data->work_tree = xstrdup(value); + } + return 0; +} + +static int check_repo_format(const char *var, const char *value, void *vdata) +{ + struct repository_format *data = vdata; + const char *ext; + + if (strcmp(var, "core.repositoryformatversion") == 0) + data->version = git_config_int(var, value); + else if (skip_prefix(var, "extensions.", &ext)) { + /* + * record any known extensions here; otherwise, + * we fall through to recording it as unknown, and + * check_repository_format will complain + */ + if (!strcmp(ext, "noop")) + ; + else if (!strcmp(ext, "preciousobjects")) + data->precious_objects = git_config_bool(var, value); + else if (!strcmp(ext, "partialclone")) { + if (!value) + return config_error_nonbool(var); + data->partial_clone = xstrdup(value); + } else if (!strcmp(ext, "worktreeconfig")) + data->worktree_config = git_config_bool(var, value); + else + string_list_append(&data->unknown_extensions, ext); + } + + return read_worktree_config(var, value, vdata); +} + +static int check_repository_format_gently(const char *gitdir, struct repository_format *candidate, int *nongit_ok) +{ + struct strbuf sb = STRBUF_INIT; + struct strbuf err = STRBUF_INIT; + int has_common; + + has_common = get_common_dir(&sb, gitdir); + strbuf_addstr(&sb, "/config"); + read_repository_format(candidate, sb.buf); + strbuf_release(&sb); + + /* + * For historical use of check_repository_format() in git-init, + * we treat a missing config as a silent "ok", even when nongit_ok + * is unset. + */ + if (candidate->version < 0) + return 0; + + if (verify_repository_format(candidate, &err) < 0) { + if (nongit_ok) { + warning("%s", err.buf); + strbuf_release(&err); + *nongit_ok = -1; + return -1; + } + die("%s", err.buf); + } + + repository_format_precious_objects = candidate->precious_objects; + set_repository_format_partial_clone(candidate->partial_clone); + repository_format_worktree_config = candidate->worktree_config; + string_list_clear(&candidate->unknown_extensions, 0); + + if (repository_format_worktree_config) { + /* + * pick up core.bare and core.worktree from per-worktree + * config if present + */ + strbuf_addf(&sb, "%s/config.worktree", gitdir); + git_config_from_file(read_worktree_config, sb.buf, candidate); + strbuf_release(&sb); + has_common = 0; + } + + if (!has_common) { + if (candidate->is_bare != -1) { + is_bare_repository_cfg = candidate->is_bare; + if (is_bare_repository_cfg == 1) + inside_work_tree = -1; + } + if (candidate->work_tree) { + free(git_work_tree_cfg); + git_work_tree_cfg = xstrdup(candidate->work_tree); + inside_work_tree = -1; + } + } + + return 0; +} + +static void init_repository_format(struct repository_format *format) +{ + const struct repository_format fresh = REPOSITORY_FORMAT_INIT; + + memcpy(format, &fresh, sizeof(fresh)); +} + +int read_repository_format(struct repository_format *format, const char *path) +{ + clear_repository_format(format); + git_config_from_file(check_repo_format, path, format); + if (format->version == -1) + clear_repository_format(format); + return format->version; +} + +void clear_repository_format(struct repository_format *format) +{ + string_list_clear(&format->unknown_extensions, 0); + free(format->work_tree); + free(format->partial_clone); + init_repository_format(format); +} + +int verify_repository_format(const struct repository_format *format, + struct strbuf *err) +{ + if (GIT_REPO_VERSION_READ < format->version) { + strbuf_addf(err, _("Expected git repo version <= %d, found %d"), + GIT_REPO_VERSION_READ, format->version); + return -1; + } + + if (format->version >= 1 && format->unknown_extensions.nr) { + int i; + + strbuf_addstr(err, _("unknown repository extensions found:")); + + for (i = 0; i < format->unknown_extensions.nr; i++) + strbuf_addf(err, "\n\t%s", + format->unknown_extensions.items[i].string); + return -1; + } + + return 0; +} + +void read_gitfile_error_die(int error_code, const char *path, const char *dir) +{ + switch (error_code) { + case READ_GITFILE_ERR_STAT_FAILED: + case READ_GITFILE_ERR_NOT_A_FILE: + /* non-fatal; follow return path */ + break; + case READ_GITFILE_ERR_OPEN_FAILED: + die_errno(_("error opening '%s'"), path); + case READ_GITFILE_ERR_TOO_LARGE: + die(_("too large to be a .git file: '%s'"), path); + case READ_GITFILE_ERR_READ_FAILED: + die(_("error reading %s"), path); + case READ_GITFILE_ERR_INVALID_FORMAT: + die(_("invalid gitfile format: %s"), path); + case READ_GITFILE_ERR_NO_PATH: + die(_("no path in gitfile: %s"), path); + case READ_GITFILE_ERR_NOT_A_REPO: + die(_("not a git repository: %s"), dir); + default: + BUG("unknown error code"); + } +} + +/* + * Try to read the location of the git directory from the .git file, + * return path to git directory if found. The return value comes from + * a shared buffer. + * + * On failure, if return_error_code is not NULL, return_error_code + * will be set to an error code and NULL will be returned. If + * return_error_code is NULL the function will die instead (for most + * cases). + */ +const char *read_gitfile_gently(const char *path, int *return_error_code) +{ + const int max_file_size = 1 << 20; /* 1MB */ + int error_code = 0; + char *buf = NULL; + char *dir = NULL; + const char *slash; + struct stat st; + int fd; + ssize_t len; + + if (stat(path, &st)) { + /* NEEDSWORK: discern between ENOENT vs other errors */ + error_code = READ_GITFILE_ERR_STAT_FAILED; + goto cleanup_return; + } + if (!S_ISREG(st.st_mode)) { + error_code = READ_GITFILE_ERR_NOT_A_FILE; + goto cleanup_return; + } + if (st.st_size > max_file_size) { + error_code = READ_GITFILE_ERR_TOO_LARGE; + goto cleanup_return; + } + fd = open(path, O_RDONLY); + if (fd < 0) { + error_code = READ_GITFILE_ERR_OPEN_FAILED; + goto cleanup_return; + } + buf = xmallocz(st.st_size); + len = read_in_full(fd, buf, st.st_size); + close(fd); + if (len != st.st_size) { + error_code = READ_GITFILE_ERR_READ_FAILED; + goto cleanup_return; + } + if (!starts_with(buf, "gitdir: ")) { + error_code = READ_GITFILE_ERR_INVALID_FORMAT; + goto cleanup_return; + } + while (buf[len - 1] == '\n' || buf[len - 1] == '\r') + len--; + if (len < 9) { + error_code = READ_GITFILE_ERR_NO_PATH; + goto cleanup_return; + } + buf[len] = '\0'; + dir = buf + 8; + + if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) { + size_t pathlen = slash+1 - path; + dir = xstrfmt("%.*s%.*s", (int)pathlen, path, + (int)(len - 8), buf + 8); + free(buf); + buf = dir; + } + if (!is_git_directory(dir)) { + error_code = READ_GITFILE_ERR_NOT_A_REPO; + goto cleanup_return; + } + path = real_path(dir); + +cleanup_return: + if (return_error_code) + *return_error_code = error_code; + else if (error_code) + read_gitfile_error_die(error_code, path, dir); + + free(buf); + return error_code ? NULL : path; +} + +static const char *setup_explicit_git_dir(const char *gitdirenv, + struct strbuf *cwd, + struct repository_format *repo_fmt, + int *nongit_ok) +{ + const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT); + const char *worktree; + char *gitfile; + int offset; + + if (PATH_MAX - 40 < strlen(gitdirenv)) + die(_("'$%s' too big"), GIT_DIR_ENVIRONMENT); + + gitfile = (char*)read_gitfile(gitdirenv); + if (gitfile) { + gitfile = xstrdup(gitfile); + gitdirenv = gitfile; + } + + if (!is_git_directory(gitdirenv)) { + if (nongit_ok) { + *nongit_ok = 1; + free(gitfile); + return NULL; + } + die(_("not a git repository: '%s'"), gitdirenv); + } + + if (check_repository_format_gently(gitdirenv, repo_fmt, nongit_ok)) { + free(gitfile); + return NULL; + } + + /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */ + if (work_tree_env) + set_git_work_tree(work_tree_env); + else if (is_bare_repository_cfg > 0) { + if (git_work_tree_cfg) { + /* #22.2, #30 */ + warning("core.bare and core.worktree do not make sense"); + work_tree_config_is_bogus = 1; + } + + /* #18, #26 */ + set_git_dir(gitdirenv); + free(gitfile); + return NULL; + } + else if (git_work_tree_cfg) { /* #6, #14 */ + if (is_absolute_path(git_work_tree_cfg)) + set_git_work_tree(git_work_tree_cfg); + else { + char *core_worktree; + if (chdir(gitdirenv)) + die_errno(_("cannot chdir to '%s'"), gitdirenv); + if (chdir(git_work_tree_cfg)) + die_errno(_("cannot chdir to '%s'"), git_work_tree_cfg); + core_worktree = xgetcwd(); + if (chdir(cwd->buf)) + die_errno(_("cannot come back to cwd")); + set_git_work_tree(core_worktree); + free(core_worktree); + } + } + else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) { + /* #16d */ + set_git_dir(gitdirenv); + free(gitfile); + return NULL; + } + else /* #2, #10 */ + set_git_work_tree("."); + + /* set_git_work_tree() must have been called by now */ + worktree = get_git_work_tree(); + + /* both get_git_work_tree() and cwd are already normalized */ + if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */ + set_git_dir(gitdirenv); + free(gitfile); + return NULL; + } + + offset = dir_inside_of(cwd->buf, worktree); + if (offset >= 0) { /* cwd inside worktree? */ + set_git_dir(real_path(gitdirenv)); + if (chdir(worktree)) + die_errno(_("cannot chdir to '%s'"), worktree); + strbuf_addch(cwd, '/'); + free(gitfile); + return cwd->buf + offset; + } + + /* cwd outside worktree */ + set_git_dir(gitdirenv); + free(gitfile); + return NULL; +} + +static const char *setup_discovered_git_dir(const char *gitdir, + struct strbuf *cwd, int offset, + struct repository_format *repo_fmt, + int *nongit_ok) +{ + if (check_repository_format_gently(gitdir, repo_fmt, nongit_ok)) + return NULL; + + /* --work-tree is set without --git-dir; use discovered one */ + if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) { + char *to_free = NULL; + const char *ret; + + if (offset != cwd->len && !is_absolute_path(gitdir)) + gitdir = to_free = real_pathdup(gitdir, 1); + if (chdir(cwd->buf)) + die_errno(_("cannot come back to cwd")); + ret = setup_explicit_git_dir(gitdir, cwd, repo_fmt, nongit_ok); + free(to_free); + return ret; + } + + /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */ + if (is_bare_repository_cfg > 0) { + set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir)); + if (chdir(cwd->buf)) + die_errno(_("cannot come back to cwd")); + return NULL; + } + + /* #0, #1, #5, #8, #9, #12, #13 */ + set_git_work_tree("."); + if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT)) + set_git_dir(gitdir); + inside_git_dir = 0; + inside_work_tree = 1; + if (offset >= cwd->len) + return NULL; + + /* Make "offset" point past the '/' (already the case for root dirs) */ + if (offset != offset_1st_component(cwd->buf)) + offset++; + /* Add a '/' at the end */ + strbuf_addch(cwd, '/'); + return cwd->buf + offset; +} + +/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */ +static const char *setup_bare_git_dir(struct strbuf *cwd, int offset, + struct repository_format *repo_fmt, + int *nongit_ok) +{ + int root_len; + + if (check_repository_format_gently(".", repo_fmt, nongit_ok)) + return NULL; + + setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1); + + /* --work-tree is set without --git-dir; use discovered one */ + if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) { + static const char *gitdir; + + gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset); + if (chdir(cwd->buf)) + die_errno(_("cannot come back to cwd")); + return setup_explicit_git_dir(gitdir, cwd, repo_fmt, nongit_ok); + } + + inside_git_dir = 1; + inside_work_tree = 0; + if (offset != cwd->len) { + if (chdir(cwd->buf)) + die_errno(_("cannot come back to cwd")); + root_len = offset_1st_component(cwd->buf); + strbuf_setlen(cwd, offset > root_len ? offset : root_len); + set_git_dir(cwd->buf); + } + else + set_git_dir("."); + return NULL; +} + +static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len) +{ + struct stat buf; + if (stat(path, &buf)) { + die_errno(_("failed to stat '%*s%s%s'"), + prefix_len, + prefix ? prefix : "", + prefix ? "/" : "", path); + } + return buf.st_dev; +} + +/* + * A "string_list_each_func_t" function that canonicalizes an entry + * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or + * discards it if unusable. The presence of an empty entry in + * GIT_CEILING_DIRECTORIES turns off canonicalization for all + * subsequent entries. + */ +static int canonicalize_ceiling_entry(struct string_list_item *item, + void *cb_data) +{ + int *empty_entry_found = cb_data; + char *ceil = item->string; + + if (!*ceil) { + *empty_entry_found = 1; + return 0; + } else if (!is_absolute_path(ceil)) { + return 0; + } else if (*empty_entry_found) { + /* Keep entry but do not canonicalize it */ + return 1; + } else { + char *real_path = real_pathdup(ceil, 0); + if (!real_path) { + return 0; + } + free(item->string); + item->string = real_path; + return 1; + } +} + +enum discovery_result { + GIT_DIR_NONE = 0, + GIT_DIR_EXPLICIT, + GIT_DIR_DISCOVERED, + GIT_DIR_BARE, + /* these are errors */ + GIT_DIR_HIT_CEILING = -1, + GIT_DIR_HIT_MOUNT_POINT = -2, + GIT_DIR_INVALID_GITFILE = -3 +}; + +/* + * We cannot decide in this function whether we are in the work tree or + * not, since the config can only be read _after_ this function was called. + * + * Also, we avoid changing any global state (such as the current working + * directory) to allow early callers. + * + * The directory where the search should start needs to be passed in via the + * `dir` parameter; upon return, the `dir` buffer will contain the path of + * the directory where the search ended, and `gitdir` will contain the path of + * the discovered .git/ directory, if any. If `gitdir` is not absolute, it + * is relative to `dir` (i.e. *not* necessarily the cwd). + */ +static enum discovery_result setup_git_directory_gently_1(struct strbuf *dir, + struct strbuf *gitdir, + int die_on_error) +{ + const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT); + struct string_list ceiling_dirs = STRING_LIST_INIT_DUP; + const char *gitdirenv; + int ceil_offset = -1, min_offset = offset_1st_component(dir->buf); + dev_t current_device = 0; + int one_filesystem = 1; + + /* + * If GIT_DIR is set explicitly, we're not going + * to do any discovery, but we still do repository + * validation. + */ + gitdirenv = getenv(GIT_DIR_ENVIRONMENT); + if (gitdirenv) { + strbuf_addstr(gitdir, gitdirenv); + return GIT_DIR_EXPLICIT; + } + + if (env_ceiling_dirs) { + int empty_entry_found = 0; + + string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1); + filter_string_list(&ceiling_dirs, 0, + canonicalize_ceiling_entry, &empty_entry_found); + ceil_offset = longest_ancestor_length(dir->buf, &ceiling_dirs); + string_list_clear(&ceiling_dirs, 0); + } + + if (ceil_offset < 0) + ceil_offset = min_offset - 2; + + if (min_offset && min_offset == dir->len && + !is_dir_sep(dir->buf[min_offset - 1])) { + strbuf_addch(dir, '/'); + min_offset++; + } + + /* + * Test in the following order (relative to the dir): + * - .git (file containing "gitdir: <path>") + * - .git/ + * - ./ (bare) + * - ../.git + * - ../.git/ + * - ../ (bare) + * - ../../.git + * etc. + */ + one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0); + if (one_filesystem) + current_device = get_device_or_die(dir->buf, NULL, 0); + for (;;) { + int offset = dir->len, error_code = 0; + + if (offset > min_offset) + strbuf_addch(dir, '/'); + strbuf_addstr(dir, DEFAULT_GIT_DIR_ENVIRONMENT); + gitdirenv = read_gitfile_gently(dir->buf, die_on_error ? + NULL : &error_code); + if (!gitdirenv) { + if (die_on_error || + error_code == READ_GITFILE_ERR_NOT_A_FILE) { + /* NEEDSWORK: fail if .git is not file nor dir */ + if (is_git_directory(dir->buf)) + gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT; + } else if (error_code != READ_GITFILE_ERR_STAT_FAILED) + return GIT_DIR_INVALID_GITFILE; + } + strbuf_setlen(dir, offset); + if (gitdirenv) { + strbuf_addstr(gitdir, gitdirenv); + return GIT_DIR_DISCOVERED; + } + + if (is_git_directory(dir->buf)) { + strbuf_addstr(gitdir, "."); + return GIT_DIR_BARE; + } + + if (offset <= min_offset) + return GIT_DIR_HIT_CEILING; + + while (--offset > ceil_offset && !is_dir_sep(dir->buf[offset])) + ; /* continue */ + if (offset <= ceil_offset) + return GIT_DIR_HIT_CEILING; + + strbuf_setlen(dir, offset > min_offset ? offset : min_offset); + if (one_filesystem && + current_device != get_device_or_die(dir->buf, NULL, offset)) + return GIT_DIR_HIT_MOUNT_POINT; + } +} + +int discover_git_directory(struct strbuf *commondir, + struct strbuf *gitdir) +{ + struct strbuf dir = STRBUF_INIT, err = STRBUF_INIT; + size_t gitdir_offset = gitdir->len, cwd_len; + size_t commondir_offset = commondir->len; + struct repository_format candidate = REPOSITORY_FORMAT_INIT; + + if (strbuf_getcwd(&dir)) + return -1; + + cwd_len = dir.len; + if (setup_git_directory_gently_1(&dir, gitdir, 0) <= 0) { + strbuf_release(&dir); + return -1; + } + + /* + * The returned gitdir is relative to dir, and if dir does not reflect + * the current working directory, we simply make the gitdir absolute. + */ + if (dir.len < cwd_len && !is_absolute_path(gitdir->buf + gitdir_offset)) { + /* Avoid a trailing "/." */ + if (!strcmp(".", gitdir->buf + gitdir_offset)) + strbuf_setlen(gitdir, gitdir_offset); + else + strbuf_addch(&dir, '/'); + strbuf_insert(gitdir, gitdir_offset, dir.buf, dir.len); + } + + get_common_dir(commondir, gitdir->buf + gitdir_offset); + + strbuf_reset(&dir); + strbuf_addf(&dir, "%s/config", commondir->buf + commondir_offset); + read_repository_format(&candidate, dir.buf); + strbuf_release(&dir); + + if (verify_repository_format(&candidate, &err) < 0) { + warning("ignoring git dir '%s': %s", + gitdir->buf + gitdir_offset, err.buf); + strbuf_release(&err); + strbuf_setlen(commondir, commondir_offset); + strbuf_setlen(gitdir, gitdir_offset); + clear_repository_format(&candidate); + return -1; + } + + clear_repository_format(&candidate); + return 0; +} + +const char *setup_git_directory_gently(int *nongit_ok) +{ + static struct strbuf cwd = STRBUF_INIT; + struct strbuf dir = STRBUF_INIT, gitdir = STRBUF_INIT; + const char *prefix = NULL; + struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT; + + /* + * We may have read an incomplete configuration before + * setting-up the git directory. If so, clear the cache so + * that the next queries to the configuration reload complete + * configuration (including the per-repo config file that we + * ignored previously). + */ + git_config_clear(); + + /* + * Let's assume that we are in a git repository. + * If it turns out later that we are somewhere else, the value will be + * updated accordingly. + */ + if (nongit_ok) + *nongit_ok = 0; + + if (strbuf_getcwd(&cwd)) + die_errno(_("Unable to read current working directory")); + strbuf_addbuf(&dir, &cwd); + + switch (setup_git_directory_gently_1(&dir, &gitdir, 1)) { + case GIT_DIR_EXPLICIT: + prefix = setup_explicit_git_dir(gitdir.buf, &cwd, &repo_fmt, nongit_ok); + break; + case GIT_DIR_DISCOVERED: + if (dir.len < cwd.len && chdir(dir.buf)) + die(_("cannot change to '%s'"), dir.buf); + prefix = setup_discovered_git_dir(gitdir.buf, &cwd, dir.len, + &repo_fmt, nongit_ok); + break; + case GIT_DIR_BARE: + if (dir.len < cwd.len && chdir(dir.buf)) + die(_("cannot change to '%s'"), dir.buf); + prefix = setup_bare_git_dir(&cwd, dir.len, &repo_fmt, nongit_ok); + break; + case GIT_DIR_HIT_CEILING: + if (!nongit_ok) + die(_("not a git repository (or any of the parent directories): %s"), + DEFAULT_GIT_DIR_ENVIRONMENT); + *nongit_ok = 1; + break; + case GIT_DIR_HIT_MOUNT_POINT: + if (!nongit_ok) + die(_("not a git repository (or any parent up to mount point %s)\n" + "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."), + dir.buf); + *nongit_ok = 1; + break; + case GIT_DIR_NONE: + /* + * As a safeguard against setup_git_directory_gently_1 returning + * this value, fallthrough to BUG. Otherwise it is possible to + * set startup_info->have_repository to 1 when we did nothing to + * find a repository. + */ + default: + BUG("unhandled setup_git_directory_1() result"); + } + + /* + * At this point, nongit_ok is stable. If it is non-NULL and points + * to a non-zero value, then this means that we haven't found a + * repository and that the caller expects startup_info to reflect + * this. + * + * Regardless of the state of nongit_ok, startup_info->prefix and + * the GIT_PREFIX environment variable must always match. For details + * see Documentation/config/alias.txt. + */ + if (nongit_ok && *nongit_ok) { + startup_info->have_repository = 0; + startup_info->prefix = NULL; + setenv(GIT_PREFIX_ENVIRONMENT, "", 1); + } else { + startup_info->have_repository = 1; + startup_info->prefix = prefix; + if (prefix) + setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1); + else + setenv(GIT_PREFIX_ENVIRONMENT, "", 1); + } + + /* + * Not all paths through the setup code will call 'set_git_dir()' (which + * directly sets up the environment) so in order to guarantee that the + * environment is in a consistent state after setup, explicitly setup + * the environment if we have a repository. + * + * NEEDSWORK: currently we allow bogus GIT_DIR values to be set in some + * code paths so we also need to explicitly setup the environment if + * the user has set GIT_DIR. It may be beneficial to disallow bogus + * GIT_DIR values at some point in the future. + */ + if (/* GIT_DIR_EXPLICIT, GIT_DIR_DISCOVERED, GIT_DIR_BARE */ + startup_info->have_repository || + /* GIT_DIR_EXPLICIT */ + getenv(GIT_DIR_ENVIRONMENT)) { + if (!the_repository->gitdir) { + const char *gitdir = getenv(GIT_DIR_ENVIRONMENT); + if (!gitdir) + gitdir = DEFAULT_GIT_DIR_ENVIRONMENT; + setup_git_env(gitdir); + } + if (startup_info->have_repository) + repo_set_hash_algo(the_repository, repo_fmt.hash_algo); + } + + strbuf_release(&dir); + strbuf_release(&gitdir); + clear_repository_format(&repo_fmt); + + return prefix; +} + +int git_config_perm(const char *var, const char *value) +{ + int i; + char *endptr; + + if (value == NULL) + return PERM_GROUP; + + if (!strcmp(value, "umask")) + return PERM_UMASK; + if (!strcmp(value, "group")) + return PERM_GROUP; + if (!strcmp(value, "all") || + !strcmp(value, "world") || + !strcmp(value, "everybody")) + return PERM_EVERYBODY; + + /* Parse octal numbers */ + i = strtol(value, &endptr, 8); + + /* If not an octal number, maybe true/false? */ + if (*endptr != 0) + return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK; + + /* + * Treat values 0, 1 and 2 as compatibility cases, otherwise it is + * a chmod value to restrict to. + */ + switch (i) { + case PERM_UMASK: /* 0 */ + return PERM_UMASK; + case OLD_PERM_GROUP: /* 1 */ + return PERM_GROUP; + case OLD_PERM_EVERYBODY: /* 2 */ + return PERM_EVERYBODY; + } + + /* A filemode value was given: 0xxx */ + + if ((i & 0600) != 0600) + die(_("problem with core.sharedRepository filemode value " + "(0%.3o).\nThe owner of files must always have " + "read and write permissions."), i); + + /* + * Mask filemode value. Others can not get write permission. + * x flags for directories are handled separately. + */ + return -(i & 0666); +} + +void check_repository_format(void) +{ + struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT; + check_repository_format_gently(get_git_dir(), &repo_fmt, NULL); + startup_info->have_repository = 1; + clear_repository_format(&repo_fmt); +} + +/* + * Returns the "prefix", a path to the current working directory + * relative to the work tree root, or NULL, if the current working + * directory is not a strict subdirectory of the work tree root. The + * prefix always ends with a '/' character. + */ +const char *setup_git_directory(void) +{ + return setup_git_directory_gently(NULL); +} + +const char *resolve_gitdir_gently(const char *suspect, int *return_error_code) +{ + if (is_git_directory(suspect)) + return suspect; + return read_gitfile_gently(suspect, return_error_code); +} + +/* if any standard file descriptor is missing open it to /dev/null */ +void sanitize_stdfds(void) +{ + int fd = open("/dev/null", O_RDWR, 0); + while (fd != -1 && fd < 2) + fd = dup(fd); + if (fd == -1) + die_errno(_("open /dev/null or dup failed")); + if (fd > 2) + close(fd); +} + +int daemonize(void) +{ +#ifdef NO_POSIX_GOODIES + errno = ENOSYS; + return -1; +#else + switch (fork()) { + case 0: + break; + case -1: + die_errno(_("fork failed")); + default: + exit(0); + } + if (setsid() == -1) + die_errno(_("setsid failed")); + close(0); + close(1); + close(2); + sanitize_stdfds(); + return 0; +#endif +} |