Merge branch 'nd/export-worktree' into maint

Running an aliased command from a subdirectory when the .git thing
in the working tree is a gitfile pointing elsewhere did not work.

* nd/export-worktree:
  setup: set env $GIT_WORK_TREE when work tree is set, like $GIT_DIR

2 files changed, 19 insertions, 0 deletions

diff --git a/environment.c b/environment.c
index 61c685b8d9..03cf5f67a6 100644
--- a/environment.c
+++ b/environment.c
@@ -231,6 +231,8 @@ void set_git_work_tree(const char *new_work_tree)
 	}
 	git_work_tree_initialized = 1;
 	work_tree = xstrdup(real_path(new_work_tree));
+	if (setenv(GIT_WORK_TREE_ENVIRONMENT, work_tree, 1))
+		die("could not set GIT_WORK_TREE to '%s'", work_tree);
 }
 
 const char *get_git_work_tree(void)
diff --git a/t/t0002-gitfile.sh b/t/t0002-gitfile.sh
index 37e9396e5d..9393322c3e 100755
--- a/t/t0002-gitfile.sh
+++ b/t/t0002-gitfile.sh
@@ -99,4 +99,21 @@ test_expect_success 'check rev-list' '
 	test "$SHA" = "$(git rev-list HEAD)"
 '
 
+test_expect_success 'setup_git_dir twice in subdir' '
+	git init sgd &&
+	(
+		cd sgd &&
+		git config alias.lsfi ls-files &&
+		mv .git .realgit &&
+		echo "gitdir: .realgit" >.git &&
+		mkdir subdir &&
+		cd subdir &&
+		>foo &&
+		git add foo &&
+		git lsfi >actual &&
+		echo foo >expected &&
+		test_cmp expected actual
+	)
+'
+
 test_done