[PATCH 3/5] grep: fix bug when recuring with relative pathspec

[Brandon Williams <bmwill@google.com>]

Fix a bug which causes a child process for a submodule to error out when
a relative pathspec with a ".." is provided in the superproject.

While at it, correctly construct the super-prefix to be used in a
submodule when not at the root of the repository.

Signed-off-by: Brandon Williams <bmwill@google.com>
---
 builtin/grep.c                     | 8 ++++++--
 t/t7814-grep-recurse-submodules.sh | 2 +-
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/builtin/grep.c b/builtin/grep.c
index 2c727ef49..65f3413d1 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -538,6 +538,7 @@ static int grep_submodule_launch(struct grep_opt *opt,
 	int status, i;
 	const char *end_of_base;
 	const char *name;
+	struct strbuf buf = STRBUF_INIT;
 	struct work_item *w = opt->output_priv;
 
 	end_of_base = strchr(gs->name, ':');
@@ -550,9 +551,11 @@ static int grep_submodule_launch(struct grep_opt *opt,
 	argv_array_push(&cp.env_array, GIT_DIR_ENVIRONMENT);
 
 	/* Add super prefix */
+	quote_path_relative(name, opt->prefix, &buf);
 	argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
 			 super_prefix ? super_prefix : "",
-			 name);
+			 buf.buf);
+	strbuf_release(&buf);
 	argv_array_push(&cp.args, "grep");
 
 	/*
@@ -1199,7 +1202,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 
 	parse_pathspec(&pathspec, 0,
 		       PATHSPEC_PREFER_CWD |
-		       (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0),
+		       (opt.max_depth != -1 ? PATHSPEC_MAXDEPTH_VALID : 0) |
+		       (super_prefix ? PATHSPEC_FROMROOT : 0),
 		       prefix, argv + i);
 	pathspec.max_depth = opt.max_depth;
 	pathspec.recursive = 1;
diff --git a/t/t7814-grep-recurse-submodules.sh b/t/t7814-grep-recurse-submodules.sh
index 418ba68fe..e0932b2b7 100755
--- a/t/t7814-grep-recurse-submodules.sh
+++ b/t/t7814-grep-recurse-submodules.sh
@@ -227,7 +227,7 @@ test_expect_success 'grep history with moved submoules' '
 	test_cmp expect actual
 '
 
-test_expect_failure 'grep using relative path' '
+test_expect_success 'grep using relative path' '
 	test_when_finished "rm -rf parent sub" &&
 	git init sub &&
 	echo "foobar" >sub/file &&
-- 
2.11.0.483.g087da7b7c-goog