[PATCH v3 7/9] mv: cleanup empty WORKING_DIRECTORY

[Shaoxuan Yuan <shaoxuan.yuan02@gmail.com>]

Originally, moving from-in-to-out may leave an empty <source>
directory on-disk (this kind of directory is marked as
WORKING_DIRECTORY).

Cleanup such directories if they are empty (don't have any entries
under them).

Modify two tests that take <source> as WORKING_DIRECTORY to test
this behavior.

Suggested-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Shaoxuan Yuan <shaoxuan.yuan02@gmail.com>
---
 builtin/mv.c                  | 27 +++++++++++++++++++++++++++
 t/t7002-mv-sparse-checkout.sh |  4 ++++
 2 files changed, 31 insertions(+)

diff --git a/builtin/mv.c b/builtin/mv.c
index 6a6420c984..32e7ac4896 100644
--- a/builtin/mv.c
+++ b/builtin/mv.c
@@ -171,6 +171,9 @@ int cmd_mv(int argc, const char **argv, const char *prefix)
 	};
 	const char **source, **destination, **dest_path, **submodule_gitfile;
 	const char *dst_w_slash;
+	const char **src_dir = NULL;
+	int src_dir_nr = 0, src_dir_alloc = 0;
+	struct strbuf a_src_dir = STRBUF_INIT;
 	enum update_mode *modes, dst_mode = 0;
 	struct stat st;
 	struct string_list src_for_dst = STRING_LIST_INIT_NODUP;
@@ -314,6 +317,10 @@ int cmd_mv(int argc, const char **argv, const char *prefix)
 
 			/* last - first >= 1 */
 			modes[i] |= WORKING_DIRECTORY;
+
+			ALLOC_GROW(src_dir, src_dir_nr + 1, src_dir_alloc);
+			src_dir[src_dir_nr++] = src;
+
 			n = argc + last - first;
 			REALLOC_ARRAY(source, n);
 			REALLOC_ARRAY(destination, n);
@@ -503,6 +510,26 @@ int cmd_mv(int argc, const char **argv, const char *prefix)
 		}
 	}
 
+	/*
+	 * cleanup the empty src_dirs
+	 */
+	for (i = 0; i < src_dir_nr; i++) {
+		int dummy;
+		strbuf_addstr(&a_src_dir, src_dir[i]);
+		/*
+		 * if entries under a_src_dir are all moved away,
+		 * recursively remove a_src_dir to cleanup
+		 */
+		if (index_range_of_same_dir(a_src_dir.buf, a_src_dir.len,
+					    &dummy, &dummy) < 1) {
+			remove_dir_recursively(&a_src_dir, 0);
+		}
+		strbuf_reset(&a_src_dir);
+	}
+
+	strbuf_release(&a_src_dir);
+	free(src_dir);
+
 	if (gitmodules_modified)
 		stage_updated_gitmodules(&the_index);
 
diff --git a/t/t7002-mv-sparse-checkout.sh b/t/t7002-mv-sparse-checkout.sh
index d875f492dd..df8c0fa572 100755
--- a/t/t7002-mv-sparse-checkout.sh
+++ b/t/t7002-mv-sparse-checkout.sh
@@ -442,6 +442,7 @@ test_expect_success 'move dirty path from in-cone to out-of-cone' '
 test_expect_success 'move dir from in-cone to out-of-cone' '
 	test_when_finished "cleanup_sparse_checkout" &&
 	setup_sparse_checkout &&
+	mkdir sub/dir/deep &&
 
 	test_must_fail git mv sub/dir folder1 2>stderr &&
 	cat sparse_error_header >expect &&
@@ -452,6 +453,7 @@ test_expect_success 'move dir from in-cone to out-of-cone' '
 	git mv --sparse sub/dir folder1 2>stderr &&
 	test_must_be_empty stderr &&
 
+	test_path_is_missing sub/dir &&
 	test_path_is_missing folder1 &&
 	git ls-files -t >actual &&
 	! grep "H sub/dir/e" actual &&
@@ -461,6 +463,7 @@ test_expect_success 'move dir from in-cone to out-of-cone' '
 test_expect_success 'move partially-dirty dir from in-cone to out-of-cone' '
 	test_when_finished "cleanup_sparse_checkout" &&
 	setup_sparse_checkout &&
+	mkdir sub/dir/deep &&
 	touch sub/dir/e2 sub/dir/e3 &&
 	git add sub/dir/e2 sub/dir/e3 &&
 	echo "modified" >>sub/dir/e2 &&
@@ -476,6 +479,7 @@ test_expect_success 'move partially-dirty dir from in-cone to out-of-cone' '
 
 	git mv --sparse sub/dir folder1 2>stderr &&
 
+	test_path_is_missing sub/dir &&
 	test_path_is_missing folder1/dir/e &&
 	test_path_is_file folder1/dir/e2 &&
 	test_path_is_file folder1/dir/e3 &&
-- 
2.37.0