cache API: add a "INDEX_STATE_INIT" macro/function, add release_index()

Hopefully in some not so distant future, we'll get advantages from always
initializing the "repo" member of the "struct index_state". To make
that easier let's introduce an initialization macro & function.

The various ad-hoc initialization of the structure can then be changed
over to it, and we can remove the various "0" assignments in
discard_index() in favor of calling index_state_init() at the end.

While not strictly necessary, let's also change the CALLOC_ARRAY() of
various "struct index_state *" to use an ALLOC_ARRAY() followed by
index_state_init() instead.

We're then adding the release_index() function and converting some
callers (including some of these allocations) over to it if they
either won't need to use their "struct index_state" again, or are just
about to call index_state_init().

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/unpack-trees.c b/unpack-trees.c
index 2381cd7cac..d1d1b0f319 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -1905,7 +1905,7 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 		populate_from_existing_patterns(o, &pl);
 	}
 
-	memset(&o->result, 0, sizeof(o->result));
+	index_state_init(&o->result);
 	o->result.initialized = 1;
 	o->result.timestamp.sec = o->src_index->timestamp.sec;
 	o->result.timestamp.nsec = o->src_index->timestamp.nsec;