Commands requiring a work tree must not run in GIT_DIR

This patch helps when you accidentally run something like git-clean
in the git directory instead of the work tree.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

builtin-ls-files.c

@@ -323,7 +323,7 @@ static const char ls_files_usage[] =
 int cmd_ls_files(int argc, const char **argv, const char *prefix)
 {
 	int i;
-	int exc_given = 0;
+	int exc_given = 0, require_work_tree = 0;
 	struct dir_struct dir;
 
 	memset(&dir, 0, sizeof(dir));
@@ -363,14 +363,17 @@ int cmd_ls_files(int argc, const char **argv, const char *prefix)
 		}
 		if (!strcmp(arg, "-m") || !strcmp(arg, "--modified")) {
 			show_modified = 1;
+			require_work_tree = 1;
 			continue;
 		}
 		if (!strcmp(arg, "-o") || !strcmp(arg, "--others")) {
 			show_others = 1;
+			require_work_tree = 1;
 			continue;
 		}
 		if (!strcmp(arg, "-i") || !strcmp(arg, "--ignored")) {
 			dir.show_ignored = 1;
+			require_work_tree = 1;
 			continue;
 		}
 		if (!strcmp(arg, "-s") || !strcmp(arg, "--stage")) {
@@ -379,6 +382,7 @@ int cmd_ls_files(int argc, const char **argv, const char *prefix)
 		}
 		if (!strcmp(arg, "-k") || !strcmp(arg, "--killed")) {
 			show_killed = 1;
+			require_work_tree = 1;
 			continue;
 		}
 		if (!strcmp(arg, "--directory")) {
@@ -447,6 +451,10 @@ int cmd_ls_files(int argc, const char **argv, const char *prefix)
 		break;
 	}
 
+	if (require_work_tree &&
+			(is_bare_repository() || is_inside_git_dir()))
+		die("This operation must be run in a work tree");
+
 	pathspec = get_pathspec(prefix, argv + i);
 
 	/* Verify that the pathspec matches the prefix */

builtin-rev-parse.c

@@ -347,6 +347,11 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 				printf("%s/.git\n", cwd);
 				continue;
 			}
+			if (!strcmp(arg, "--is-inside-git-dir")) {
+				printf("%s\n", is_inside_git_dir() ? "true"
+						: "false");
+				continue;
+			}
 			if (!strncmp(arg, "--since=", 8)) {
 				show_datestring("--max-age=", arg+8);
 				continue;

git-sh-setup.sh

@@ -48,7 +48,8 @@ cd_to_toplevel () {
 }
 
 require_work_tree () {
-	test $(is_bare_repository) = false ||
+	test $(is_bare_repository) = false &&
+	test $(git-rev-parse --is-inside-git-dir) = false ||
 	die "fatal: $0 cannot be used without a working tree."
 }
 

git.c

@@ -299,8 +299,9 @@ static void handle_internal_command(int argc, const char **argv, char **envp)
 			prefix = setup_git_directory();
 		if (p->option & USE_PAGER)
 			setup_pager();
-		if ((p->option & NOT_BARE) && is_bare_repository())
-			die("%s cannot be used in a bare git directory", cmd);
+		if ((p->option & NOT_BARE) &&
+				(is_bare_repository() || is_inside_git_dir()))
+			die("%s must be run in a work tree", cmd);
 		trace_argv_printf(argv, argc, "trace: built-in: git");
 
 		exit(p->fn(argc, argv, prefix));