1 files changed, 148 insertions, 66 deletions
diff --git a/setup.c b/setup.c
index cf47441b7b..3a6a048620 100644
--- a/setup.c
+++ b/setup.c
@@ -22,7 +22,6 @@
 #include "chdir-notify.h"
 #include "path.h"
 #include "quote.h"
-#include "tmp-objdir.h"
 #include "trace.h"
 #include "trace2.h"
 #include "worktree.h"
@@ -1002,6 +1001,83 @@ cleanup_return:
 	return error_code ? NULL : path;
 }
 
+static void setup_git_env_internal(const char *git_dir,
+				   bool skip_initializing_odb)
+{
+	char *git_replace_ref_base;
+	const char *shallow_file;
+	const char *replace_ref_base;
+	struct set_gitdir_args args = { NULL };
+	struct strvec to_free = STRVEC_INIT;
+
+	args.commondir = getenv_safe(&to_free, GIT_COMMON_DIR_ENVIRONMENT);
+	args.object_dir = getenv_safe(&to_free, DB_ENVIRONMENT);
+	args.graft_file = getenv_safe(&to_free, GRAFT_ENVIRONMENT);
+	args.index_file = getenv_safe(&to_free, INDEX_ENVIRONMENT);
+	args.alternate_db = getenv_safe(&to_free, ALTERNATE_DB_ENVIRONMENT);
+	if (getenv(GIT_QUARANTINE_ENVIRONMENT))
+		args.disable_ref_updates = true;
+	args.skip_initializing_odb = skip_initializing_odb;
+
+	repo_set_gitdir(the_repository, git_dir, &args);
+	strvec_clear(&to_free);
+
+	if (getenv(NO_REPLACE_OBJECTS_ENVIRONMENT))
+		disable_replace_refs();
+	replace_ref_base = getenv(GIT_REPLACE_REF_BASE_ENVIRONMENT);
+	git_replace_ref_base = xstrdup(replace_ref_base ? replace_ref_base
+							  : "refs/replace/");
+	update_ref_namespace(NAMESPACE_REPLACE, git_replace_ref_base);
+
+	shallow_file = getenv(GIT_SHALLOW_FILE_ENVIRONMENT);
+	if (shallow_file)
+		set_alternate_shallow_file(the_repository, shallow_file, 0);
+
+	if (git_env_bool(NO_LAZY_FETCH_ENVIRONMENT, 0))
+		fetch_if_missing = 0;
+}
+
+void setup_git_env(const char *git_dir)
+{
+	setup_git_env_internal(git_dir, false);
+}
+
+static void set_git_dir_1(const char *path, bool skip_initializing_odb)
+{
+	xsetenv(GIT_DIR_ENVIRONMENT, path, 1);
+	setup_git_env_internal(path, skip_initializing_odb);
+}
+
+static void update_relative_gitdir(const char *name UNUSED,
+				   const char *old_cwd,
+				   const char *new_cwd,
+				   void *data UNUSED)
+{
+	char *path = reparent_relative_path(old_cwd, new_cwd,
+					    repo_get_git_dir(the_repository));
+	trace_printf_key(&trace_setup_key,
+			 "setup: move $GIT_DIR to '%s'",
+			 path);
+	set_git_dir_1(path, true);
+	free(path);
+}
+
+static void set_git_dir(const char *path, int make_realpath)
+{
+	struct strbuf realpath = STRBUF_INIT;
+
+	if (make_realpath) {
+		strbuf_realpath(&realpath, path, 1);
+		path = realpath.buf;
+	}
+
+	set_git_dir_1(path, false);
+	if (!is_absolute_path(path))
+		chdir_notify_register(NULL, update_relative_gitdir, NULL);
+
+	strbuf_release(&realpath);
+}
+
 static const char *setup_explicit_git_dir(const char *gitdirenv,
 					  struct strbuf *cwd,
 					  struct repository_format *repo_fmt,
@@ -1628,79 +1704,85 @@ enum discovery_result discover_git_directory_reason(struct strbuf *commondir,
 	return result;
 }
 
-void setup_git_env(const char *git_dir)
-{
-	char *git_replace_ref_base;
-	const char *shallow_file;
-	const char *replace_ref_base;
-	struct set_gitdir_args args = { NULL };
-	struct strvec to_free = STRVEC_INIT;
-
-	args.commondir = getenv_safe(&to_free, GIT_COMMON_DIR_ENVIRONMENT);
-	args.object_dir = getenv_safe(&to_free, DB_ENVIRONMENT);
-	args.graft_file = getenv_safe(&to_free, GRAFT_ENVIRONMENT);
-	args.index_file = getenv_safe(&to_free, INDEX_ENVIRONMENT);
-	args.alternate_db = getenv_safe(&to_free, ALTERNATE_DB_ENVIRONMENT);
-	if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
-		args.disable_ref_updates = 1;
-	}
-
-	repo_set_gitdir(the_repository, git_dir, &args);
-	strvec_clear(&to_free);
-
-	if (getenv(NO_REPLACE_OBJECTS_ENVIRONMENT))
-		disable_replace_refs();
-	replace_ref_base = getenv(GIT_REPLACE_REF_BASE_ENVIRONMENT);
-	git_replace_ref_base = xstrdup(replace_ref_base ? replace_ref_base
-							  : "refs/replace/");
-	update_ref_namespace(NAMESPACE_REPLACE, git_replace_ref_base);
-
-	shallow_file = getenv(GIT_SHALLOW_FILE_ENVIRONMENT);
-	if (shallow_file)
-		set_alternate_shallow_file(the_repository, shallow_file, 0);
-
-	if (git_env_bool(NO_LAZY_FETCH_ENVIRONMENT, 0))
-		fetch_if_missing = 0;
-}
-
-static void set_git_dir_1(const char *path)
+const char *enter_repo(const char *path, unsigned flags)
 {
-	xsetenv(GIT_DIR_ENVIRONMENT, path, 1);
-	setup_git_env(path);
-}
+	static struct strbuf validated_path = STRBUF_INIT;
+	static struct strbuf used_path = STRBUF_INIT;
 
-static void update_relative_gitdir(const char *name UNUSED,
-				   const char *old_cwd,
-				   const char *new_cwd,
-				   void *data UNUSED)
-{
-	char *path = reparent_relative_path(old_cwd, new_cwd,
-					    repo_get_git_dir(the_repository));
-	struct tmp_objdir *tmp_objdir = tmp_objdir_unapply_primary_odb();
+	if (!path)
+		return NULL;
 
-	trace_printf_key(&trace_setup_key,
-			 "setup: move $GIT_DIR to '%s'",
-			 path);
-	set_git_dir_1(path);
-	if (tmp_objdir)
-		tmp_objdir_reapply_primary_odb(tmp_objdir, old_cwd, new_cwd);
-	free(path);
-}
+	if (!(flags & ENTER_REPO_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--;
 
-void set_git_dir(const char *path, int make_realpath)
-{
-	struct strbuf realpath = STRBUF_INIT;
+		/*
+		 * We can handle arbitrary-sized buffers, but this remains as a
+		 * sanity check on untrusted input.
+		 */
+		if (PATH_MAX <= len)
+			return NULL;
 
-	if (make_realpath) {
-		strbuf_realpath(&realpath, path, 1);
-		path = realpath.buf;
+		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 = interpolate_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 (!(flags & ENTER_REPO_ANY_OWNER_OK))
+			die_upon_dubious_ownership(gitfile, NULL, 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 (!(flags & ENTER_REPO_ANY_OWNER_OK))
+			die_upon_dubious_ownership(gitfile, NULL, path);
+		if (gitfile)
+			path = gitfile;
+		if (chdir(path))
+			return NULL;
 	}
 
-	set_git_dir_1(path);
-	if (!is_absolute_path(path))
-		chdir_notify_register(NULL, update_relative_gitdir, NULL);
+	if (is_git_directory(".")) {
+		set_git_dir(".", 0);
+		check_repository_format(NULL);
+		return path;
+	}
 
-	strbuf_release(&realpath);
+	return NULL;
 }
 
 static int git_work_tree_initialized;