[PATCH v2] reset: unstage empty deleted ita files

[Varun Naik <vcnaik94@gmail.com>]

It is possible to delete a committed file from the index and then add it
as intent-to-add. After `git reset HEAD`, the file should be identical
in the index and HEAD. This patch provides the desired behavior even
when the file is empty in the index.

Signed-off-by: Varun Naik <vcnaik94@gmail.com>
---
CC Duy because you seem to be the one who is most involved in changes to
ita behavior.

The test description was incorrect, so I changed that now. I also
figured out how to fix the related problem in "restore"; separate patch
coming soon.

 builtin/reset.c  |  1 +
 t/t7102-reset.sh | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/builtin/reset.c b/builtin/reset.c
index 26ef9a7bd0..47a088f4b7 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -163,6 +163,7 @@ static int read_from_tree(const struct pathspec *pathspec,
 	opt.format_callback_data = &intent_to_add;
 	opt.flags.override_submodule_config = 1;
 	opt.repo = the_repository;
+	opt.ita_invisible_in_index = 1;
 
 	if (do_diff_cache(tree_oid, &opt))
 		return 1;
diff --git a/t/t7102-reset.sh b/t/t7102-reset.sh
index 97be0d968d..9f3854e8f0 100755
--- a/t/t7102-reset.sh
+++ b/t/t7102-reset.sh
@@ -566,4 +566,15 @@ test_expect_success 'reset --mixed sets up work tree' '
 	test_must_be_empty actual
 '
 
+test_expect_success 'reset --mixed adds deleted intent-to-add file back to index' '
+	echo "nonempty" >nonempty &&
+	>empty &&
+	git add nonempty empty &&
+	git commit -m "create files to be deleted" &&
+	git rm --cached nonempty empty &&
+	git add -N nonempty empty &&
+	git reset HEAD nonempty empty &&
+	git diff --staged --exit-code
+'
+
 test_done
-- 
2.22.0