[PATCH] grep: die gracefully when outside repository

[Kristoffer Haugsbakk <code@khaugsbakk.name>]

Die gracefully when `git grep --no-index` is run outside of a Git
repository and the path is outside the directory tree.

If you are not in a Git repository and say:

    git grep --no-index search ..

You trigger a `BUG`:

    BUG: environment.c:213: git environment hasn't been setup
    Aborted (core dumped)

Because `..` is a valid path which is treated as a pathspec. Then
`pathspec` figures out that it is not in the current directory tree. The
`BUG` is triggered when `pathspec` tries to advice the user about the path
to the (non-existing) repository.

Reported-by: ks1322 ks1322 <ks1322@gmail.com>
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
---
 pathspec.c      |  3 +++
 t/t7810-grep.sh | 13 +++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/pathspec.c b/pathspec.c
index 3a3a5724c44..e115832f17a 100644
--- a/pathspec.c
+++ b/pathspec.c
@@ -468,6 +468,9 @@ static void init_pathspec_item(struct pathspec_item *item, unsigned flags,
 					   &prefixlen, copyfrom);
 		if (!match) {
 			const char *hint_path = get_git_work_tree();
+			if (!have_git_dir())
+				die(_("'%s' is outside the directory tree"),
+				    copyfrom);
 			if (!hint_path)
 				hint_path = get_git_dir();
 			die(_("%s: '%s' is outside repository at '%s'"), elt,
diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index 39d6d713ecb..b976f81a166 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -1234,6 +1234,19 @@ test_expect_success 'outside of git repository with fallbackToNoIndex' '
 	)
 '
 
+test_expect_success 'outside of git repository with pathspec outside the directory tree' '
+	test_when_finished rm -fr non &&
+	rm -fr non &&
+	mkdir -p non/git/sub &&
+	(
+		GIT_CEILING_DIRECTORIES="$(pwd)/non" &&
+		export GIT_CEILING_DIRECTORIES &&
+		cd non/git &&
+		test_expect_code 128 git grep --no-index search .. 2>error &&
+		grep "is outside the directory tree" error
+	)
+'
+
 test_expect_success 'inside git repository but with --no-index' '
 	rm -fr is &&
 	mkdir -p is/git/sub &&

base-commit: 43c8a30d150ecede9709c1f2527c8fba92c65f40
-- 
2.42.0.2.g879ad04204