1 files changed, 156 insertions, 68 deletions

diff --git a/setup.c b/setup.c
index 5432a31..979b13f 100644
--- a/setup.c
+++ b/setup.c
@@ -6,6 +6,70 @@ static int inside_git_dir = -1;
 static int inside_work_tree = -1;
 
 /*
+ * 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 && !strncmp(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 (strcmp(real_path(path0), work_tree) == 0) {
+				memmove(path0, path + 1, len - (path - path0));
+				return 0;
+			}
+			*path = '/';
+		}
+	}
+
+	/* check whole path */
+	if (strcmp(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
@@ -22,11 +86,17 @@ char *prefix_path_gently(const char *prefix, int len,
 	const char *orig = path;
 	char *sanitized;
 	if (is_absolute_path(orig)) {
-		const char *temp = real_path(path);
-		sanitized = xmalloc(len + strlen(temp) + 1);
-		strcpy(sanitized, temp);
+		sanitized = xmalloc(strlen(path) + 1);
 		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 = xmalloc(len + strlen(path) + 1);
 		if (len)
@@ -34,26 +104,10 @@ char *prefix_path_gently(const char *prefix, int len,
 		strcpy(sanitized + len, path);
 		if (remaining_prefix)
 			*remaining_prefix = len;
-	}
-	if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix))
-		goto error_out;
-	if (is_absolute_path(orig)) {
-		size_t root_len, len, total;
-		const char *work_tree = get_git_work_tree();
-		if (!work_tree)
-			goto error_out;
-		len = strlen(work_tree);
-		root_len = offset_1st_component(work_tree);
-		total = strlen(sanitized) + 1;
-		if (strncmp(sanitized, work_tree, len) ||
-		    (len > root_len && sanitized[len] != '\0' && sanitized[len] != '/')) {
-		error_out:
+		if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) {
 			free(sanitized);
 			return NULL;
 		}
-		if (sanitized[len] == '/')
-			len++;
-		memmove(sanitized, sanitized + len, total - len);
 	}
 	return sanitized;
 }
@@ -82,7 +136,7 @@ int check_filename(const char *prefix, const char *arg)
 	const char *name;
 	struct stat st;
 
-	if (!prefixcmp(arg, ":/")) {
+	if (starts_with(arg, ":/")) {
 		if (arg[2] == '\0') /* ":/" is root dir, always exists */
 			return 1;
 		name = arg + 2;
@@ -304,7 +358,7 @@ const char *read_gitfile(const char *path)
 	if (len != st.st_size)
 		die("Error reading %s", path);
 	buf[len] = '\0';
-	if (prefixcmp(buf, "gitdir: "))
+	if (!starts_with(buf, "gitdir: "))
 		die("Invalid gitfile format: %s", path);
 	while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 		len--;
@@ -333,7 +387,7 @@ const char *read_gitfile(const char *path)
 }
 
 static const char *setup_explicit_git_dir(const char *gitdirenv,
-					  char *cwd, int len,
+					  struct strbuf *cwd,
 					  int *nongit_ok)
 {
 	const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
@@ -380,16 +434,16 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 		if (is_absolute_path(git_work_tree_cfg))
 			set_git_work_tree(git_work_tree_cfg);
 		else {
-			char core_worktree[PATH_MAX];
+			char *core_worktree;
 			if (chdir(gitdirenv))
 				die_errno("Could not chdir to '%s'", gitdirenv);
 			if (chdir(git_work_tree_cfg))
 				die_errno("Could not chdir to '%s'", git_work_tree_cfg);
-			if (!getcwd(core_worktree, PATH_MAX))
-				die_errno("Could not get directory '%s'", git_work_tree_cfg);
-			if (chdir(cwd))
+			core_worktree = xgetcwd();
+			if (chdir(cwd->buf))
 				die_errno("Could not come back to cwd");
 			set_git_work_tree(core_worktree);
+			free(core_worktree);
 		}
 	}
 	else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
@@ -405,21 +459,20 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 	worktree = get_git_work_tree();
 
 	/* both get_git_work_tree() and cwd are already normalized */
-	if (!strcmp(cwd, worktree)) { /* cwd == worktree */
+	if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
 		set_git_dir(gitdirenv);
 		free(gitfile);
 		return NULL;
 	}
 
-	offset = dir_inside_of(cwd, worktree);
+	offset = dir_inside_of(cwd->buf, worktree);
 	if (offset >= 0) {	/* cwd inside worktree? */
 		set_git_dir(real_path(gitdirenv));
 		if (chdir(worktree))
 			die_errno("Could not chdir to '%s'", worktree);
-		cwd[len++] = '/';
-		cwd[len] = '\0';
+		strbuf_addch(cwd, '/');
 		free(gitfile);
-		return cwd + offset;
+		return cwd->buf + offset;
 	}
 
 	/* cwd outside worktree */
@@ -429,7 +482,7 @@ static const char *setup_explicit_git_dir(const char *gitdirenv,
 }
 
 static const char *setup_discovered_git_dir(const char *gitdir,
-					    char *cwd, int offset, int len,
+					    struct strbuf *cwd, int offset,
 					    int *nongit_ok)
 {
 	if (check_repository_format_gently(gitdir, nongit_ok))
@@ -437,17 +490,17 @@ static const char *setup_discovered_git_dir(const char *gitdir,
 
 	/* --work-tree is set without --git-dir; use discovered one */
 	if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
-		if (offset != len && !is_absolute_path(gitdir))
+		if (offset != cwd->len && !is_absolute_path(gitdir))
 			gitdir = xstrdup(real_path(gitdir));
-		if (chdir(cwd))
+		if (chdir(cwd->buf))
 			die_errno("Could not come back to cwd");
-		return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
+		return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 	}
 
 	/* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 	if (is_bare_repository_cfg > 0) {
-		set_git_dir(offset == len ? gitdir : real_path(gitdir));
-		if (chdir(cwd))
+		set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
+		if (chdir(cwd->buf))
 			die_errno("Could not come back to cwd");
 		return NULL;
 	}
@@ -458,18 +511,18 @@ static const char *setup_discovered_git_dir(const char *gitdir,
 		set_git_dir(gitdir);
 	inside_git_dir = 0;
 	inside_work_tree = 1;
-	if (offset == len)
+	if (offset == cwd->len)
 		return NULL;
 
 	/* Make "offset" point to past the '/', and add a '/' at the end */
 	offset++;
-	cwd[len++] = '/';
-	cwd[len] = 0;
-	return cwd + offset;
+	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(char *cwd, int offset, int len, int *nongit_ok)
+static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
+				      int *nongit_ok)
 {
 	int root_len;
 
@@ -482,20 +535,20 @@ static const char *setup_bare_git_dir(char *cwd, int offset, int len, int *nongi
 	if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 		const char *gitdir;
 
-		gitdir = offset == len ? "." : xmemdupz(cwd, offset);
-		if (chdir(cwd))
+		gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
+		if (chdir(cwd->buf))
 			die_errno("Could not come back to cwd");
-		return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
+		return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 	}
 
 	inside_git_dir = 1;
 	inside_work_tree = 0;
-	if (offset != len) {
-		if (chdir(cwd))
+	if (offset != cwd->len) {
+		if (chdir(cwd->buf))
 			die_errno("Cannot come back to cwd");
-		root_len = offset_1st_component(cwd);
-		cwd[offset > root_len ? offset : root_len] = '\0';
-		set_git_dir(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(".");
@@ -563,14 +616,23 @@ static const char *setup_git_directory_gently_1(int *nongit_ok)
 {
 	const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 	struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
-	static char cwd[PATH_MAX + 1];
+	static struct strbuf cwd = STRBUF_INIT;
 	const char *gitdirenv, *ret;
 	char *gitfile;
-	int len, offset, offset_parent, ceil_offset = -1;
+	int offset, offset_parent, ceil_offset = -1;
 	dev_t current_device = 0;
 	int one_filesystem = 1;
 
 	/*
+	 * 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.
@@ -578,9 +640,9 @@ static const char *setup_git_directory_gently_1(int *nongit_ok)
 	if (nongit_ok)
 		*nongit_ok = 0;
 
-	if (!getcwd(cwd, sizeof(cwd) - 1))
+	if (strbuf_getcwd(&cwd))
 		die_errno("Unable to read current working directory");
-	offset = len = strlen(cwd);
+	offset = cwd.len;
 
 	/*
 	 * If GIT_DIR is set explicitly, we're not going
@@ -589,7 +651,7 @@ static const char *setup_git_directory_gently_1(int *nongit_ok)
 	 */
 	gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 	if (gitdirenv)
-		return setup_explicit_git_dir(gitdirenv, cwd, len, nongit_ok);
+		return setup_explicit_git_dir(gitdirenv, &cwd, nongit_ok);
 
 	if (env_ceiling_dirs) {
 		int empty_entry_found = 0;
@@ -597,11 +659,11 @@ static const char *setup_git_directory_gently_1(int *nongit_ok)
 		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(cwd, &ceiling_dirs);
+		ceil_offset = longest_ancestor_length(cwd.buf, &ceiling_dirs);
 		string_list_clear(&ceiling_dirs, 0);
 	}
 
-	if (ceil_offset < 0 && has_dos_drive_prefix(cwd))
+	if (ceil_offset < 0 && has_dos_drive_prefix(cwd.buf))
 		ceil_offset = 1;
 
 	/*
@@ -629,7 +691,7 @@ static const char *setup_git_directory_gently_1(int *nongit_ok)
 
 		if (gitdirenv) {
 			ret = setup_discovered_git_dir(gitdirenv,
-						       cwd, offset, len,
+						       &cwd, offset,
 						       nongit_ok);
 			free(gitfile);
 			return ret;
@@ -637,29 +699,31 @@ static const char *setup_git_directory_gently_1(int *nongit_ok)
 		free(gitfile);
 
 		if (is_git_directory("."))
-			return setup_bare_git_dir(cwd, offset, len, nongit_ok);
+			return setup_bare_git_dir(&cwd, offset, nongit_ok);
 
 		offset_parent = offset;
-		while (--offset_parent > ceil_offset && cwd[offset_parent] != '/');
+		while (--offset_parent > ceil_offset && cwd.buf[offset_parent] != '/');
 		if (offset_parent <= ceil_offset)
-			return setup_nongit(cwd, nongit_ok);
+			return setup_nongit(cwd.buf, nongit_ok);
 		if (one_filesystem) {
-			dev_t parent_device = get_device_or_die("..", cwd, offset);
+			dev_t parent_device = get_device_or_die("..", cwd.buf,
+								offset);
 			if (parent_device != current_device) {
 				if (nongit_ok) {
-					if (chdir(cwd))
+					if (chdir(cwd.buf))
 						die_errno("Cannot come back to cwd");
 					*nongit_ok = 1;
 					return NULL;
 				}
-				cwd[offset] = '\0';
+				strbuf_setlen(&cwd, offset);
 				die("Not a git repository (or any parent up to mount point %s)\n"
-				"Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).", cwd);
+				"Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).",
+				    cwd.buf);
 			}
 		}
 		if (chdir("..")) {
-			cwd[offset] = '\0';
-			die_errno("Cannot change to '%s/..'", cwd);
+			strbuf_setlen(&cwd, offset);
+			die_errno("Cannot change to '%s/..'", cwd.buf);
 		}
 		offset = offset_parent;
 	}
@@ -787,3 +851,27 @@ void sanitize_stdfds(void)
 	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
+}