diff options
Diffstat (limited to 'third_party/git/path.c')
| -rw-r--r-- | third_party/git/path.c | 1539 |
1 files changed, 1539 insertions, 0 deletions
diff --git a/third_party/git/path.c b/third_party/git/path.c new file mode 100644 index 000000000000..88cf59300738 --- /dev/null +++ b/third_party/git/path.c @@ -0,0 +1,1539 @@ +/* + * Utilities for paths and pathnames + */ +#include "cache.h" +#include "repository.h" +#include "strbuf.h" +#include "string-list.h" +#include "dir.h" +#include "worktree.h" +#include "submodule-config.h" +#include "path.h" +#include "packfile.h" +#include "object-store.h" +#include "lockfile.h" + +static int get_st_mode_bits(const char *path, int *mode) +{ + struct stat st; + if (lstat(path, &st) < 0) + return -1; + *mode = st.st_mode; + return 0; +} + +static char bad_path[] = "/bad-path/"; + +static struct strbuf *get_pathname(void) +{ + static struct strbuf pathname_array[4] = { + STRBUF_INIT, STRBUF_INIT, STRBUF_INIT, STRBUF_INIT + }; + static int index; + struct strbuf *sb = &pathname_array[index]; + index = (index + 1) % ARRAY_SIZE(pathname_array); + strbuf_reset(sb); + return sb; +} + +static const char *cleanup_path(const char *path) +{ + /* Clean it up */ + if (skip_prefix(path, "./", &path)) { + while (*path == '/') + path++; + } + return path; +} + +static void strbuf_cleanup_path(struct strbuf *sb) +{ + const char *path = cleanup_path(sb->buf); + if (path > sb->buf) + strbuf_remove(sb, 0, path - sb->buf); +} + +char *mksnpath(char *buf, size_t n, const char *fmt, ...) +{ + va_list args; + unsigned len; + + va_start(args, fmt); + len = vsnprintf(buf, n, fmt, args); + va_end(args); + if (len >= n) { + strlcpy(buf, bad_path, n); + return buf; + } + return (char *)cleanup_path(buf); +} + +static int dir_prefix(const char *buf, const char *dir) +{ + int len = strlen(dir); + return !strncmp(buf, dir, len) && + (is_dir_sep(buf[len]) || buf[len] == '\0'); +} + +/* $buf =~ m|$dir/+$file| but without regex */ +static int is_dir_file(const char *buf, const char *dir, const char *file) +{ + int len = strlen(dir); + if (strncmp(buf, dir, len) || !is_dir_sep(buf[len])) + return 0; + while (is_dir_sep(buf[len])) + len++; + return !strcmp(buf + len, file); +} + +static void replace_dir(struct strbuf *buf, int len, const char *newdir) +{ + int newlen = strlen(newdir); + int need_sep = (buf->buf[len] && !is_dir_sep(buf->buf[len])) && + !is_dir_sep(newdir[newlen - 1]); + if (need_sep) + len--; /* keep one char, to be replaced with '/' */ + strbuf_splice(buf, 0, len, newdir, newlen); + if (need_sep) + buf->buf[newlen] = '/'; +} + +struct common_dir { + /* Not considered garbage for report_linked_checkout_garbage */ + unsigned ignore_garbage:1; + unsigned is_dir:1; + /* Belongs to the common dir, though it may contain paths that don't */ + unsigned is_common:1; + const char *path; +}; + +static struct common_dir common_list[] = { + { 0, 1, 1, "branches" }, + { 0, 1, 1, "common" }, + { 0, 1, 1, "hooks" }, + { 0, 1, 1, "info" }, + { 0, 0, 0, "info/sparse-checkout" }, + { 1, 1, 1, "logs" }, + { 1, 0, 0, "logs/HEAD" }, + { 0, 1, 0, "logs/refs/bisect" }, + { 0, 1, 0, "logs/refs/rewritten" }, + { 0, 1, 0, "logs/refs/worktree" }, + { 0, 1, 1, "lost-found" }, + { 0, 1, 1, "objects" }, + { 0, 1, 1, "refs" }, + { 0, 1, 0, "refs/bisect" }, + { 0, 1, 0, "refs/rewritten" }, + { 0, 1, 0, "refs/worktree" }, + { 0, 1, 1, "remotes" }, + { 0, 1, 1, "worktrees" }, + { 0, 1, 1, "rr-cache" }, + { 0, 1, 1, "svn" }, + { 0, 0, 1, "config" }, + { 1, 0, 1, "gc.pid" }, + { 0, 0, 1, "packed-refs" }, + { 0, 0, 1, "shallow" }, + { 0, 0, 0, NULL } +}; + +/* + * A compressed trie. A trie node consists of zero or more characters that + * are common to all elements with this prefix, optionally followed by some + * children. If value is not NULL, the trie node is a terminal node. + * + * For example, consider the following set of strings: + * abc + * def + * definite + * definition + * + * The trie would look like: + * root: len = 0, children a and d non-NULL, value = NULL. + * a: len = 2, contents = bc, value = (data for "abc") + * d: len = 2, contents = ef, children i non-NULL, value = (data for "def") + * i: len = 3, contents = nit, children e and i non-NULL, value = NULL + * e: len = 0, children all NULL, value = (data for "definite") + * i: len = 2, contents = on, children all NULL, + * value = (data for "definition") + */ +struct trie { + struct trie *children[256]; + int len; + char *contents; + void *value; +}; + +static struct trie *make_trie_node(const char *key, void *value) +{ + struct trie *new_node = xcalloc(1, sizeof(*new_node)); + new_node->len = strlen(key); + if (new_node->len) { + new_node->contents = xmalloc(new_node->len); + memcpy(new_node->contents, key, new_node->len); + } + new_node->value = value; + return new_node; +} + +/* + * Add a key/value pair to a trie. The key is assumed to be \0-terminated. + * If there was an existing value for this key, return it. + */ +static void *add_to_trie(struct trie *root, const char *key, void *value) +{ + struct trie *child; + void *old; + int i; + + if (!*key) { + /* we have reached the end of the key */ + old = root->value; + root->value = value; + return old; + } + + for (i = 0; i < root->len; i++) { + if (root->contents[i] == key[i]) + continue; + + /* + * Split this node: child will contain this node's + * existing children. + */ + child = xmalloc(sizeof(*child)); + memcpy(child->children, root->children, sizeof(root->children)); + + child->len = root->len - i - 1; + if (child->len) { + child->contents = xstrndup(root->contents + i + 1, + child->len); + } + child->value = root->value; + root->value = NULL; + root->len = i; + + memset(root->children, 0, sizeof(root->children)); + root->children[(unsigned char)root->contents[i]] = child; + + /* This is the newly-added child. */ + root->children[(unsigned char)key[i]] = + make_trie_node(key + i + 1, value); + return NULL; + } + + /* We have matched the entire compressed section */ + if (key[i]) { + child = root->children[(unsigned char)key[root->len]]; + if (child) { + return add_to_trie(child, key + root->len + 1, value); + } else { + child = make_trie_node(key + root->len + 1, value); + root->children[(unsigned char)key[root->len]] = child; + return NULL; + } + } + + old = root->value; + root->value = value; + return old; +} + +typedef int (*match_fn)(const char *unmatched, void *value, void *baton); + +/* + * Search a trie for some key. Find the longest /-or-\0-terminated + * prefix of the key for which the trie contains a value. If there is + * no such prefix, return -1. Otherwise call fn with the unmatched + * portion of the key and the found value. If fn returns 0 or + * positive, then return its return value. If fn returns negative, + * then call fn with the next-longest /-terminated prefix of the key + * (i.e. a parent directory) for which the trie contains a value, and + * handle its return value the same way. If there is no shorter + * /-terminated prefix with a value left, then return the negative + * return value of the most recent fn invocation. + * + * The key is partially normalized: consecutive slashes are skipped. + * + * For example, consider the trie containing only [logs, + * logs/refs/bisect], both with values, but not logs/refs. + * + * | key | unmatched | prefix to node | return value | + * |--------------------|----------------|------------------|--------------| + * | a | not called | n/a | -1 | + * | logstore | not called | n/a | -1 | + * | logs | \0 | logs | as per fn | + * | logs/ | / | logs | as per fn | + * | logs/refs | /refs | logs | as per fn | + * | logs/refs/ | /refs/ | logs | as per fn | + * | logs/refs/b | /refs/b | logs | as per fn | + * | logs/refs/bisected | /refs/bisected | logs | as per fn | + * | logs/refs/bisect | \0 | logs/refs/bisect | as per fn | + * | logs/refs/bisect/ | / | logs/refs/bisect | as per fn | + * | logs/refs/bisect/a | /a | logs/refs/bisect | as per fn | + * | (If fn in the previous line returns -1, then fn is called once more:) | + * | logs/refs/bisect/a | /refs/bisect/a | logs | as per fn | + * |--------------------|----------------|------------------|--------------| + */ +static int trie_find(struct trie *root, const char *key, match_fn fn, + void *baton) +{ + int i; + int result; + struct trie *child; + + if (!*key) { + /* we have reached the end of the key */ + if (root->value && !root->len) + return fn(key, root->value, baton); + else + return -1; + } + + for (i = 0; i < root->len; i++) { + /* Partial path normalization: skip consecutive slashes. */ + if (key[i] == '/' && key[i+1] == '/') { + key++; + continue; + } + if (root->contents[i] != key[i]) + return -1; + } + + /* Matched the entire compressed section */ + key += i; + if (!*key) { + /* End of key */ + if (root->value) + return fn(key, root->value, baton); + else + return -1; + } + + /* Partial path normalization: skip consecutive slashes */ + while (key[0] == '/' && key[1] == '/') + key++; + + child = root->children[(unsigned char)*key]; + if (child) + result = trie_find(child, key + 1, fn, baton); + else + result = -1; + + if (result >= 0 || (*key != '/' && *key != 0)) + return result; + if (root->value) + return fn(key, root->value, baton); + else + return -1; +} + +static struct trie common_trie; +static int common_trie_done_setup; + +static void init_common_trie(void) +{ + struct common_dir *p; + + if (common_trie_done_setup) + return; + + for (p = common_list; p->path; p++) + add_to_trie(&common_trie, p->path, p); + + common_trie_done_setup = 1; +} + +/* + * Helper function for update_common_dir: returns 1 if the dir + * prefix is common. + */ +static int check_common(const char *unmatched, void *value, void *baton) +{ + struct common_dir *dir = value; + + if (dir->is_dir && (unmatched[0] == 0 || unmatched[0] == '/')) + return dir->is_common; + + if (!dir->is_dir && unmatched[0] == 0) + return dir->is_common; + + return 0; +} + +static void update_common_dir(struct strbuf *buf, int git_dir_len, + const char *common_dir) +{ + char *base = buf->buf + git_dir_len; + int has_lock_suffix = strbuf_strip_suffix(buf, LOCK_SUFFIX); + + init_common_trie(); + if (trie_find(&common_trie, base, check_common, NULL) > 0) + replace_dir(buf, git_dir_len, common_dir); + + if (has_lock_suffix) + strbuf_addstr(buf, LOCK_SUFFIX); +} + +void report_linked_checkout_garbage(void) +{ + struct strbuf sb = STRBUF_INIT; + const struct common_dir *p; + int len; + + if (!the_repository->different_commondir) + return; + strbuf_addf(&sb, "%s/", get_git_dir()); + len = sb.len; + for (p = common_list; p->path; p++) { + const char *path = p->path; + if (p->ignore_garbage) + continue; + strbuf_setlen(&sb, len); + strbuf_addstr(&sb, path); + if (file_exists(sb.buf)) + report_garbage(PACKDIR_FILE_GARBAGE, sb.buf); + } + strbuf_release(&sb); +} + +static void adjust_git_path(const struct repository *repo, + struct strbuf *buf, int git_dir_len) +{ + const char *base = buf->buf + git_dir_len; + if (is_dir_file(base, "info", "grafts")) + strbuf_splice(buf, 0, buf->len, + repo->graft_file, strlen(repo->graft_file)); + else if (!strcmp(base, "index")) + strbuf_splice(buf, 0, buf->len, + repo->index_file, strlen(repo->index_file)); + else if (dir_prefix(base, "objects")) + replace_dir(buf, git_dir_len + 7, repo->objects->odb->path); + else if (git_hooks_path && dir_prefix(base, "hooks")) + replace_dir(buf, git_dir_len + 5, git_hooks_path); + else if (repo->different_commondir) + update_common_dir(buf, git_dir_len, repo->commondir); +} + +static void strbuf_worktree_gitdir(struct strbuf *buf, + const struct repository *repo, + const struct worktree *wt) +{ + if (!wt) + strbuf_addstr(buf, repo->gitdir); + else if (!wt->id) + strbuf_addstr(buf, repo->commondir); + else + strbuf_git_common_path(buf, repo, "worktrees/%s", wt->id); +} + +static void do_git_path(const struct repository *repo, + const struct worktree *wt, struct strbuf *buf, + const char *fmt, va_list args) +{ + int gitdir_len; + strbuf_worktree_gitdir(buf, repo, wt); + if (buf->len && !is_dir_sep(buf->buf[buf->len - 1])) + strbuf_addch(buf, '/'); + gitdir_len = buf->len; + strbuf_vaddf(buf, fmt, args); + if (!wt) + adjust_git_path(repo, buf, gitdir_len); + strbuf_cleanup_path(buf); +} + +char *repo_git_path(const struct repository *repo, + const char *fmt, ...) +{ + struct strbuf path = STRBUF_INIT; + va_list args; + va_start(args, fmt); + do_git_path(repo, NULL, &path, fmt, args); + va_end(args); + return strbuf_detach(&path, NULL); +} + +void strbuf_repo_git_path(struct strbuf *sb, + const struct repository *repo, + const char *fmt, ...) +{ + va_list args; + va_start(args, fmt); + do_git_path(repo, NULL, sb, fmt, args); + va_end(args); +} + +char *git_path_buf(struct strbuf *buf, const char *fmt, ...) +{ + va_list args; + strbuf_reset(buf); + va_start(args, fmt); + do_git_path(the_repository, NULL, buf, fmt, args); + va_end(args); + return buf->buf; +} + +void strbuf_git_path(struct strbuf *sb, const char *fmt, ...) +{ + va_list args; + va_start(args, fmt); + do_git_path(the_repository, NULL, sb, fmt, args); + va_end(args); +} + +const char *git_path(const char *fmt, ...) +{ + struct strbuf *pathname = get_pathname(); + va_list args; + va_start(args, fmt); + do_git_path(the_repository, NULL, pathname, fmt, args); + va_end(args); + return pathname->buf; +} + +char *git_pathdup(const char *fmt, ...) +{ + struct strbuf path = STRBUF_INIT; + va_list args; + va_start(args, fmt); + do_git_path(the_repository, NULL, &path, fmt, args); + va_end(args); + return strbuf_detach(&path, NULL); +} + +char *mkpathdup(const char *fmt, ...) +{ + struct strbuf sb = STRBUF_INIT; + va_list args; + va_start(args, fmt); + strbuf_vaddf(&sb, fmt, args); + va_end(args); + strbuf_cleanup_path(&sb); + return strbuf_detach(&sb, NULL); +} + +const char *mkpath(const char *fmt, ...) +{ + va_list args; + struct strbuf *pathname = get_pathname(); + va_start(args, fmt); + strbuf_vaddf(pathname, fmt, args); + va_end(args); + return cleanup_path(pathname->buf); +} + +const char *worktree_git_path(const struct worktree *wt, const char *fmt, ...) +{ + struct strbuf *pathname = get_pathname(); + va_list args; + va_start(args, fmt); + do_git_path(the_repository, wt, pathname, fmt, args); + va_end(args); + return pathname->buf; +} + +static void do_worktree_path(const struct repository *repo, + struct strbuf *buf, + const char *fmt, va_list args) +{ + strbuf_addstr(buf, repo->worktree); + if(buf->len && !is_dir_sep(buf->buf[buf->len - 1])) + strbuf_addch(buf, '/'); + + strbuf_vaddf(buf, fmt, args); + strbuf_cleanup_path(buf); +} + +char *repo_worktree_path(const struct repository *repo, const char *fmt, ...) +{ + struct strbuf path = STRBUF_INIT; + va_list args; + + if (!repo->worktree) + return NULL; + + va_start(args, fmt); + do_worktree_path(repo, &path, fmt, args); + va_end(args); + + return strbuf_detach(&path, NULL); +} + +void strbuf_repo_worktree_path(struct strbuf *sb, + const struct repository *repo, + const char *fmt, ...) +{ + va_list args; + + if (!repo->worktree) + return; + + va_start(args, fmt); + do_worktree_path(repo, sb, fmt, args); + va_end(args); +} + +/* Returns 0 on success, negative on failure. */ +static int do_submodule_path(struct strbuf *buf, const char *path, + const char *fmt, va_list args) +{ + struct strbuf git_submodule_common_dir = STRBUF_INIT; + struct strbuf git_submodule_dir = STRBUF_INIT; + int ret; + + ret = submodule_to_gitdir(&git_submodule_dir, path); + if (ret) + goto cleanup; + + strbuf_complete(&git_submodule_dir, '/'); + strbuf_addbuf(buf, &git_submodule_dir); + strbuf_vaddf(buf, fmt, args); + + if (get_common_dir_noenv(&git_submodule_common_dir, git_submodule_dir.buf)) + update_common_dir(buf, git_submodule_dir.len, git_submodule_common_dir.buf); + + strbuf_cleanup_path(buf); + +cleanup: + strbuf_release(&git_submodule_dir); + strbuf_release(&git_submodule_common_dir); + return ret; +} + +char *git_pathdup_submodule(const char *path, const char *fmt, ...) +{ + int err; + va_list args; + struct strbuf buf = STRBUF_INIT; + va_start(args, fmt); + err = do_submodule_path(&buf, path, fmt, args); + va_end(args); + if (err) { + strbuf_release(&buf); + return NULL; + } + return strbuf_detach(&buf, NULL); +} + +int strbuf_git_path_submodule(struct strbuf *buf, const char *path, + const char *fmt, ...) +{ + int err; + va_list args; + va_start(args, fmt); + err = do_submodule_path(buf, path, fmt, args); + va_end(args); + + return err; +} + +static void do_git_common_path(const struct repository *repo, + struct strbuf *buf, + const char *fmt, + va_list args) +{ + strbuf_addstr(buf, repo->commondir); + if (buf->len && !is_dir_sep(buf->buf[buf->len - 1])) + strbuf_addch(buf, '/'); + strbuf_vaddf(buf, fmt, args); + strbuf_cleanup_path(buf); +} + +const char *git_common_path(const char *fmt, ...) +{ + struct strbuf *pathname = get_pathname(); + va_list args; + va_start(args, fmt); + do_git_common_path(the_repository, pathname, fmt, args); + va_end(args); + return pathname->buf; +} + +void strbuf_git_common_path(struct strbuf *sb, + const struct repository *repo, + const char *fmt, ...) +{ + va_list args; + va_start(args, fmt); + do_git_common_path(repo, sb, fmt, args); + va_end(args); +} + +int validate_headref(const char *path) +{ + struct stat st; + char buffer[256]; + const char *refname; + struct object_id oid; + int fd; + ssize_t len; + + if (lstat(path, &st) < 0) + return -1; + + /* Make sure it is a "refs/.." symlink */ + if (S_ISLNK(st.st_mode)) { + len = readlink(path, buffer, sizeof(buffer)-1); + if (len >= 5 && !memcmp("refs/", buffer, 5)) + return 0; + return -1; + } + + /* + * Anything else, just open it and try to see if it is a symbolic ref. + */ + fd = open(path, O_RDONLY); + if (fd < 0) + return -1; + len = read_in_full(fd, buffer, sizeof(buffer)-1); + close(fd); + + if (len < 0) + return -1; + buffer[len] = '\0'; + + /* + * Is it a symbolic ref? + */ + if (skip_prefix(buffer, "ref:", &refname)) { + while (isspace(*refname)) + refname++; + if (starts_with(refname, "refs/")) + return 0; + } + + /* + * Is this a detached HEAD? + */ + if (!get_oid_hex(buffer, &oid)) + return 0; + + return -1; +} + +static struct passwd *getpw_str(const char *username, size_t len) +{ + struct passwd *pw; + char *username_z = xmemdupz(username, len); + pw = getpwnam(username_z); + free(username_z); + return pw; +} + +/* + * Return a string with ~ and ~user expanded via getpw*. If buf != NULL, + * then it is a newly allocated string. Returns NULL on getpw failure or + * if path is NULL. + * + * If real_home is true, real_path($HOME) is used in the expansion. + */ +char *expand_user_path(const char *path, int real_home) +{ + struct strbuf user_path = STRBUF_INIT; + const char *to_copy = path; + + if (path == NULL) + goto return_null; + if (path[0] == '~') { + const char *first_slash = strchrnul(path, '/'); + const char *username = path + 1; + size_t username_len = first_slash - username; + if (username_len == 0) { + const char *home = getenv("HOME"); + if (!home) + goto return_null; + if (real_home) + strbuf_add_real_path(&user_path, home); + else + strbuf_addstr(&user_path, home); +#ifdef GIT_WINDOWS_NATIVE + convert_slashes(user_path.buf); +#endif + } else { + struct passwd *pw = getpw_str(username, username_len); + if (!pw) + goto return_null; + strbuf_addstr(&user_path, pw->pw_dir); + } + to_copy = first_slash; + } + strbuf_addstr(&user_path, to_copy); + return strbuf_detach(&user_path, NULL); +return_null: + strbuf_release(&user_path); + return NULL; +} + +/* + * First, one directory to try is determined by the following algorithm. + * + * (0) If "strict" is given, the path is used as given and no DWIM is + * done. Otherwise: + * (1) "~/path" to mean path under the running user's home directory; + * (2) "~user/path" to mean path under named user's home directory; + * (3) "relative/path" to mean cwd relative directory; or + * (4) "/absolute/path" to mean absolute directory. + * + * Unless "strict" is given, we check "%s/.git", "%s", "%s.git/.git", "%s.git" + * in this order. We select the first one that is a valid git repository, and + * chdir() to it. If none match, or we fail to chdir, we return NULL. + * + * If all goes well, we return the directory we used to chdir() (but + * before ~user is expanded), avoiding getcwd() resolving symbolic + * links. User relative paths are also returned as they are given, + * except DWIM suffixing. + */ +const char *enter_repo(const char *path, int strict) +{ + static struct strbuf validated_path = STRBUF_INIT; + static struct strbuf used_path = STRBUF_INIT; + + if (!path) + return NULL; + + if (!strict) { + static const char *suffix[] = { + "/.git", "", ".git/.git", ".git", NULL, + }; + const char *gitfile; + int len = strlen(path); + int i; + while ((1 < len) && (path[len-1] == '/')) + len--; + + /* + * We can handle arbitrary-sized buffers, but this remains as a + * sanity check on untrusted input. + */ + if (PATH_MAX <= len) + return NULL; + + strbuf_reset(&used_path); + strbuf_reset(&validated_path); + strbuf_add(&used_path, path, len); + strbuf_add(&validated_path, path, len); + + if (used_path.buf[0] == '~') { + char *newpath = expand_user_path(used_path.buf, 0); + if (!newpath) + return NULL; + strbuf_attach(&used_path, newpath, strlen(newpath), + strlen(newpath)); + } + for (i = 0; suffix[i]; i++) { + struct stat st; + size_t baselen = used_path.len; + strbuf_addstr(&used_path, suffix[i]); + if (!stat(used_path.buf, &st) && + (S_ISREG(st.st_mode) || + (S_ISDIR(st.st_mode) && is_git_directory(used_path.buf)))) { + strbuf_addstr(&validated_path, suffix[i]); + break; + } + strbuf_setlen(&used_path, baselen); + } + if (!suffix[i]) + return NULL; + gitfile = read_gitfile(used_path.buf); + if (gitfile) { + strbuf_reset(&used_path); + strbuf_addstr(&used_path, gitfile); + } + if (chdir(used_path.buf)) + return NULL; + path = validated_path.buf; + } + else { + const char *gitfile = read_gitfile(path); + if (gitfile) + path = gitfile; + if (chdir(path)) + return NULL; + } + + if (is_git_directory(".")) { + set_git_dir("."); + check_repository_format(); + return path; + } + + return NULL; +} + +static int calc_shared_perm(int mode) +{ + int tweak; + + if (get_shared_repository() < 0) + tweak = -get_shared_repository(); + else + tweak = get_shared_repository(); + + if (!(mode & S_IWUSR)) + tweak &= ~0222; + if (mode & S_IXUSR) + /* Copy read bits to execute bits */ + tweak |= (tweak & 0444) >> 2; + if (get_shared_repository() < 0) + mode = (mode & ~0777) | tweak; + else + mode |= tweak; + + return mode; +} + + +int adjust_shared_perm(const char *path) +{ + int old_mode, new_mode; + + if (!get_shared_repository()) + return 0; + if (get_st_mode_bits(path, &old_mode) < 0) + return -1; + + new_mode = calc_shared_perm(old_mode); + if (S_ISDIR(old_mode)) { + /* Copy read bits to execute bits */ + new_mode |= (new_mode & 0444) >> 2; + new_mode |= FORCE_DIR_SET_GID; + } + + if (((old_mode ^ new_mode) & ~S_IFMT) && + chmod(path, (new_mode & ~S_IFMT)) < 0) + return -2; + return 0; +} + +void safe_create_dir(const char *dir, int share) +{ + if (mkdir(dir, 0777) < 0) { + if (errno != EEXIST) { + perror(dir); + exit(1); + } + } + else if (share && adjust_shared_perm(dir)) + die(_("Could not make %s writable by group"), dir); +} + +static int have_same_root(const char *path1, const char *path2) +{ + int is_abs1, is_abs2; + + is_abs1 = is_absolute_path(path1); + is_abs2 = is_absolute_path(path2); + return (is_abs1 && is_abs2 && tolower(path1[0]) == tolower(path2[0])) || + (!is_abs1 && !is_abs2); +} + +/* + * Give path as relative to prefix. + * + * The strbuf may or may not be used, so do not assume it contains the + * returned path. + */ +const char *relative_path(const char *in, const char *prefix, + struct strbuf *sb) +{ + int in_len = in ? strlen(in) : 0; + int prefix_len = prefix ? strlen(prefix) : 0; + int in_off = 0; + int prefix_off = 0; + int i = 0, j = 0; + + if (!in_len) + return "./"; + else if (!prefix_len) + return in; + + if (have_same_root(in, prefix)) + /* bypass dos_drive, for "c:" is identical to "C:" */ + i = j = has_dos_drive_prefix(in); + else { + return in; + } + + while (i < prefix_len && j < in_len && prefix[i] == in[j]) { + if (is_dir_sep(prefix[i])) { + while (is_dir_sep(prefix[i])) + i++; + while (is_dir_sep(in[j])) + j++; + prefix_off = i; + in_off = j; + } else { + i++; + j++; + } + } + + if ( + /* "prefix" seems like prefix of "in" */ + i >= prefix_len && + /* + * but "/foo" is not a prefix of "/foobar" + * (i.e. prefix not end with '/') + */ + prefix_off < prefix_len) { + if (j >= in_len) { + /* in="/a/b", prefix="/a/b" */ + in_off = in_len; + } else if (is_dir_sep(in[j])) { + /* in="/a/b/c", prefix="/a/b" */ + while (is_dir_sep(in[j])) + j++; + in_off = j; + } else { + /* in="/a/bbb/c", prefix="/a/b" */ + i = prefix_off; + } + } else if ( + /* "in" is short than "prefix" */ + j >= in_len && + /* "in" not end with '/' */ + in_off < in_len) { + if (is_dir_sep(prefix[i])) { + /* in="/a/b", prefix="/a/b/c/" */ + while (is_dir_sep(prefix[i])) + i++; + in_off = in_len; + } + } + in += in_off; + in_len -= in_off; + + if (i >= prefix_len) { + if (!in_len) + return "./"; + else + return in; + } + + strbuf_reset(sb); + strbuf_grow(sb, in_len); + + while (i < prefix_len) { + if (is_dir_sep(prefix[i])) { + strbuf_addstr(sb, "../"); + while (is_dir_sep(prefix[i])) + i++; + continue; + } + i++; + } + if (!is_dir_sep(prefix[prefix_len - 1])) + strbuf_addstr(sb, "../"); + + strbuf_addstr(sb, in); + + return sb->buf; +} + +/* + * A simpler implementation of relative_path + * + * Get relative path by removing "prefix" from "in". This function + * first appears in v1.5.6-1-g044bbbc, and makes git_dir shorter + * to increase performance when traversing the path to work_tree. + */ +const char *remove_leading_path(const char *in, const char *prefix) +{ + static struct strbuf buf = STRBUF_INIT; + int i = 0, j = 0; + + if (!prefix || !prefix[0]) + return in; + while (prefix[i]) { + if (is_dir_sep(prefix[i])) { + if (!is_dir_sep(in[j])) + return in; + while (is_dir_sep(prefix[i])) + i++; + while (is_dir_sep(in[j])) + j++; + continue; + } else if (in[j] != prefix[i]) { + return in; + } + i++; + j++; + } + if ( + /* "/foo" is a prefix of "/foo" */ + in[j] && + /* "/foo" is not a prefix of "/foobar" */ + !is_dir_sep(prefix[i-1]) && !is_dir_sep(in[j]) + ) + return in; + while (is_dir_sep(in[j])) + j++; + + strbuf_reset(&buf); + if (!in[j]) + strbuf_addstr(&buf, "."); + else + strbuf_addstr(&buf, in + j); + return buf.buf; +} + +/* + * It is okay if dst == src, but they should not overlap otherwise. + * The "dst" buffer must be at least as long as "src"; normalizing may shrink + * the size of the path, but will never grow it. + * + * Performs the following normalizations on src, storing the result in dst: + * - Ensures that components are separated by '/' (Windows only) + * - Squashes sequences of '/' except "//server/share" on Windows + * - Removes "." components. + * - Removes ".." components, and the components the precede them. + * Returns failure (non-zero) if a ".." component appears as first path + * component anytime during the normalization. Otherwise, returns success (0). + * + * Note that this function is purely textual. It does not follow symlinks, + * verify the existence of the path, or make any system calls. + * + * prefix_len != NULL is for a specific case of prefix_pathspec(): + * assume that src == dst and src[0..prefix_len-1] is already + * normalized, any time "../" eats up to the prefix_len part, + * prefix_len is reduced. In the end prefix_len is the remaining + * prefix that has not been overridden by user pathspec. + * + * NEEDSWORK: This function doesn't perform normalization w.r.t. trailing '/'. + * For everything but the root folder itself, the normalized path should not + * end with a '/', then the callers need to be fixed up accordingly. + * + */ +int normalize_path_copy_len(char *dst, const char *src, int *prefix_len) +{ + char *dst0; + const char *end; + + /* + * Copy initial part of absolute path: "/", "C:/", "//server/share/". + */ + end = src + offset_1st_component(src); + while (src < end) { + char c = *src++; + if (is_dir_sep(c)) + c = '/'; + *dst++ = c; + } + dst0 = dst; + + while (is_dir_sep(*src)) + src++; + + for (;;) { + char c = *src; + + /* + * A path component that begins with . could be + * special: + * (1) "." and ends -- ignore and terminate. + * (2) "./" -- ignore them, eat slash and continue. + * (3) ".." and ends -- strip one and terminate. + * (4) "../" -- strip one, eat slash and continue. + */ + if (c == '.') { + if (!src[1]) { + /* (1) */ + src++; + } else if (is_dir_sep(src[1])) { + /* (2) */ + src += 2; + while (is_dir_sep(*src)) + src++; + continue; + } else if (src[1] == '.') { + if (!src[2]) { + /* (3) */ + src += 2; + goto up_one; + } else if (is_dir_sep(src[2])) { + /* (4) */ + src += 3; + while (is_dir_sep(*src)) + src++; + goto up_one; + } + } + } + + /* copy up to the next '/', and eat all '/' */ + while ((c = *src++) != '\0' && !is_dir_sep(c)) + *dst++ = c; + if (is_dir_sep(c)) { + *dst++ = '/'; + while (is_dir_sep(c)) + c = *src++; + src--; + } else if (!c) + break; + continue; + + up_one: + /* + * dst0..dst is prefix portion, and dst[-1] is '/'; + * go up one level. + */ + dst--; /* go to trailing '/' */ + if (dst <= dst0) + return -1; + /* Windows: dst[-1] cannot be backslash anymore */ + while (dst0 < dst && dst[-1] != '/') + dst--; + if (prefix_len && *prefix_len > dst - dst0) + *prefix_len = dst - dst0; + } + *dst = '\0'; + return 0; +} + +int normalize_path_copy(char *dst, const char *src) +{ + return normalize_path_copy_len(dst, src, NULL); +} + +/* + * path = Canonical absolute path + * prefixes = string_list containing normalized, absolute paths without + * trailing slashes (except for the root directory, which is denoted by "/"). + * + * Determines, for each path in prefixes, whether the "prefix" + * is an ancestor directory of path. Returns the length of the longest + * ancestor directory, excluding any trailing slashes, or -1 if no prefix + * is an ancestor. (Note that this means 0 is returned if prefixes is + * ["/"].) "/foo" is not considered an ancestor of "/foobar". Directories + * are not considered to be their own ancestors. path must be in a + * canonical form: empty components, or "." or ".." components are not + * allowed. + */ +int longest_ancestor_length(const char *path, struct string_list *prefixes) +{ + int i, max_len = -1; + + if (!strcmp(path, "/")) + return -1; + + for (i = 0; i < prefixes->nr; i++) { + const char *ceil = prefixes->items[i].string; + int len = strlen(ceil); + + if (len == 1 && ceil[0] == '/') + len = 0; /* root matches anything, with length 0 */ + else if (!strncmp(path, ceil, len) && path[len] == '/') + ; /* match of length len */ + else + continue; /* no match */ + + if (len > max_len) + max_len = len; + } + + return max_len; +} + +/* strip arbitrary amount of directory separators at end of path */ +static inline int chomp_trailing_dir_sep(const char *path, int len) +{ + while (len && is_dir_sep(path[len - 1])) + len--; + return len; +} + +/* + * If path ends with suffix (complete path components), returns the offset of + * the last character in the path before the suffix (sans trailing directory + * separators), and -1 otherwise. + */ +static ssize_t stripped_path_suffix_offset(const char *path, const char *suffix) +{ + int path_len = strlen(path), suffix_len = strlen(suffix); + + while (suffix_len) { + if (!path_len) + return -1; + + if (is_dir_sep(path[path_len - 1])) { + if (!is_dir_sep(suffix[suffix_len - 1])) + return -1; + path_len = chomp_trailing_dir_sep(path, path_len); + suffix_len = chomp_trailing_dir_sep(suffix, suffix_len); + } + else if (path[--path_len] != suffix[--suffix_len]) + return -1; + } + + if (path_len && !is_dir_sep(path[path_len - 1])) + return -1; + return chomp_trailing_dir_sep(path, path_len); +} + +/* + * Returns true if the path ends with components, considering only complete path + * components, and false otherwise. + */ +int ends_with_path_components(const char *path, const char *components) +{ + return stripped_path_suffix_offset(path, components) != -1; +} + +/* + * If path ends with suffix (complete path components), returns the + * part before suffix (sans trailing directory separators). + * Otherwise returns NULL. + */ +char *strip_path_suffix(const char *path, const char *suffix) +{ + ssize_t offset = stripped_path_suffix_offset(path, suffix); + + return offset == -1 ? NULL : xstrndup(path, offset); +} + +int daemon_avoid_alias(const char *p) +{ + int sl, ndot; + + /* + * This resurrects the belts and suspenders paranoia check by HPA + * done in <435560F7.4080006@zytor.com> thread, now enter_repo() + * does not do getcwd() based path canonicalization. + * + * sl becomes true immediately after seeing '/' and continues to + * be true as long as dots continue after that without intervening + * non-dot character. + */ + if (!p || (*p != '/' && *p != '~')) + return -1; + sl = 1; ndot = 0; + p++; + + while (1) { + char ch = *p++; + if (sl) { + if (ch == '.') + ndot++; + else if (ch == '/') { + if (ndot < 3) + /* reject //, /./ and /../ */ + return -1; + ndot = 0; + } + else if (ch == 0) { + if (0 < ndot && ndot < 3) + /* reject /.$ and /..$ */ + return -1; + return 0; + } + else + sl = ndot = 0; + } + else if (ch == 0) + return 0; + else if (ch == '/') { + sl = 1; + ndot = 0; + } + } +} + +/* + * On NTFS, we need to be careful to disallow certain synonyms of the `.git/` + * directory: + * + * - For historical reasons, file names that end in spaces or periods are + * automatically trimmed. Therefore, `.git . . ./` is a valid way to refer + * to `.git/`. + * + * - For other historical reasons, file names that do not conform to the 8.3 + * format (up to eight characters for the basename, three for the file + * extension, certain characters not allowed such as `+`, etc) are associated + * with a so-called "short name", at least on the `C:` drive by default. + * Which means that `git~1/` is a valid way to refer to `.git/`. + * + * Note: Technically, `.git/` could receive the short name `git~2` if the + * short name `git~1` were already used. In Git, however, we guarantee that + * `.git` is the first item in a directory, therefore it will be associated + * with the short name `git~1` (unless short names are disabled). + * + * - For yet other historical reasons, NTFS supports so-called "Alternate Data + * Streams", i.e. metadata associated with a given file, referred to via + * `<filename>:<stream-name>:<stream-type>`. There exists a default stream + * type for directories, allowing `.git/` to be accessed via + * `.git::$INDEX_ALLOCATION/`. + * + * When this function returns 1, it indicates that the specified file/directory + * name refers to a `.git` file or directory, or to any of these synonyms, and + * Git should therefore not track it. + * + * For performance reasons, _all_ Alternate Data Streams of `.git/` are + * forbidden, not just `::$INDEX_ALLOCATION`. + * + * This function is intended to be used by `git fsck` even on platforms where + * the backslash is a regular filename character, therefore it needs to handle + * backlash characters in the provided `name` specially: they are interpreted + * as directory separators. + */ +int is_ntfs_dotgit(const char *name) +{ + char c; + + /* + * Note that when we don't find `.git` or `git~1` we end up with `name` + * advanced partway through the string. That's okay, though, as we + * return immediately in those cases, without looking at `name` any + * further. + */ + c = *(name++); + if (c == '.') { + /* .git */ + if (((c = *(name++)) != 'g' && c != 'G') || + ((c = *(name++)) != 'i' && c != 'I') || + ((c = *(name++)) != 't' && c != 'T')) + return 0; + } else if (c == 'g' || c == 'G') { + /* git ~1 */ + if (((c = *(name++)) != 'i' && c != 'I') || + ((c = *(name++)) != 't' && c != 'T') || + *(name++) != '~' || + *(name++) != '1') + return 0; + } else + return 0; + + for (;;) { + c = *(name++); + if (!c || c == '\\' || c == '/' || c == ':') + return 1; + if (c != '.' && c != ' ') + return 0; + } +} + +static int is_ntfs_dot_generic(const char *name, + const char *dotgit_name, + size_t len, + const char *dotgit_ntfs_shortname_prefix) +{ + int saw_tilde; + size_t i; + + if ((name[0] == '.' && !strncasecmp(name + 1, dotgit_name, len))) { + i = len + 1; +only_spaces_and_periods: + for (;;) { + char c = name[i++]; + if (!c || c == ':') + return 1; + if (c != ' ' && c != '.') + return 0; + } + } + + /* + * Is it a regular NTFS short name, i.e. shortened to 6 characters, + * followed by ~1, ... ~4? + */ + if (!strncasecmp(name, dotgit_name, 6) && name[6] == '~' && + name[7] >= '1' && name[7] <= '4') { + i = 8; + goto only_spaces_and_periods; + } + + /* + * Is it a fall-back NTFS short name (for details, see + * https://en.wikipedia.org/wiki/8.3_filename? + */ + for (i = 0, saw_tilde = 0; i < 8; i++) + if (name[i] == '\0') + return 0; + else if (saw_tilde) { + if (name[i] < '0' || name[i] > '9') + return 0; + } else if (name[i] == '~') { + if (name[++i] < '1' || name[i] > '9') + return 0; + saw_tilde = 1; + } else if (i >= 6) + return 0; + else if (name[i] & 0x80) { + /* + * We know our needles contain only ASCII, so we clamp + * here to make the results of tolower() sane. + */ + return 0; + } else if (tolower(name[i]) != dotgit_ntfs_shortname_prefix[i]) + return 0; + + goto only_spaces_and_periods; +} + +/* + * Inline helper to make sure compiler resolves strlen() on literals at + * compile time. + */ +static inline int is_ntfs_dot_str(const char *name, const char *dotgit_name, + const char *dotgit_ntfs_shortname_prefix) +{ + return is_ntfs_dot_generic(name, dotgit_name, strlen(dotgit_name), + dotgit_ntfs_shortname_prefix); +} + +int is_ntfs_dotgitmodules(const char *name) +{ + return is_ntfs_dot_str(name, "gitmodules", "gi7eba"); +} + +int is_ntfs_dotgitignore(const char *name) +{ + return is_ntfs_dot_str(name, "gitignore", "gi250a"); +} + +int is_ntfs_dotgitattributes(const char *name) +{ + return is_ntfs_dot_str(name, "gitattributes", "gi7d29"); +} + +int looks_like_command_line_option(const char *str) +{ + return str && str[0] == '-'; +} + +char *xdg_config_home(const char *filename) +{ + const char *home, *config_home; + + assert(filename); + config_home = getenv("XDG_CONFIG_HOME"); + if (config_home && *config_home) + return mkpathdup("%s/git/%s", config_home, filename); + + home = getenv("HOME"); + if (home) + return mkpathdup("%s/.config/git/%s", home, filename); + return NULL; +} + +char *xdg_cache_home(const char *filename) +{ + const char *home, *cache_home; + + assert(filename); + cache_home = getenv("XDG_CACHE_HOME"); + if (cache_home && *cache_home) + return mkpathdup("%s/git/%s", cache_home, filename); + + home = getenv("HOME"); + if (home) + return mkpathdup("%s/.cache/git/%s", home, filename); + return NULL; +} + +REPO_GIT_PATH_FUNC(cherry_pick_head, "CHERRY_PICK_HEAD") +REPO_GIT_PATH_FUNC(revert_head, "REVERT_HEAD") +REPO_GIT_PATH_FUNC(squash_msg, "SQUASH_MSG") +REPO_GIT_PATH_FUNC(merge_msg, "MERGE_MSG") +REPO_GIT_PATH_FUNC(merge_rr, "MERGE_RR") +REPO_GIT_PATH_FUNC(merge_mode, "MERGE_MODE") +REPO_GIT_PATH_FUNC(merge_head, "MERGE_HEAD") +REPO_GIT_PATH_FUNC(fetch_head, "FETCH_HEAD") +REPO_GIT_PATH_FUNC(shallow, "shallow") |