grep: die gracefully when outside repository

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 advise the user about how the
path is not in the current (non-existing) repository.

Reported-by: ks1322 ks1322 <ks1322@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index 39d6d713ec..84838c0fe1 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -1234,6 +1234,33 @@ test_expect_success 'outside of git repository with fallbackToNoIndex' '
 	)
 '
 
+test_expect_success 'no repository with path outside $cwd' '
+	test_when_finished rm -fr non &&
+	rm -fr non &&
+	mkdir -p non/git/sub non/tig &&
+	(
+		GIT_CEILING_DIRECTORIES="$(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
+	) &&
+	(
+		GIT_CEILING_DIRECTORIES="$(pwd)/non" &&
+		export GIT_CEILING_DIRECTORIES &&
+		cd non/git &&
+		test_expect_code 128 git grep --no-index search ../tig 2>error &&
+		grep "is outside the directory tree" error
+	) &&
+	(
+		GIT_CEILING_DIRECTORIES="$(pwd)/non" &&
+		export GIT_CEILING_DIRECTORIES &&
+		cd non/git &&
+		test_expect_code 128 git grep --no-index search ../non 2>error &&
+		grep "no such path in the working tree" error
+	)
+'
+
 test_expect_success 'inside git repository but with --no-index' '
 	rm -fr is &&
 	mkdir -p is/git/sub &&