Merge branch 'ab/cache-api-cleanup' into ab/cache-api-cleanup-users

* ab/cache-api-cleanup:
  cache API: add a "INDEX_STATE_INIT" macro/function, add release_index()
  read-cache.c: refactor set_new_index_sparsity() for subsequent commit
  sparse-index API: BUG() out on NULL ensure_full_index()
  sparse-index.c: expand_to_path() can assume non-NULL "istate"
  builtin/difftool.c: { 0 }-initialize rather than using memset()

1 files changed, 13 insertions, 0 deletions

diff --git a/cache.h b/cache.h
index 21ed9633b2..be28fce12a 100644
--- a/cache.h
+++ b/cache.h
@@ -360,6 +360,19 @@ struct index_state {
 	struct pattern_list *sparse_checkout_patterns;
 };
 
+/**
+ * A "struct index_state istate" must be initialized with
+ * INDEX_STATE_INIT or the corresponding index_state_init().
+ *
+ * If the variable won't be used again, use release_index() to free()
+ * its resources. If it needs to be used again use discard_index(),
+ * which does the same thing, but will use use index_state_init() at
+ * the end.
+ */
+#define INDEX_STATE_INIT { 0 }
+void index_state_init(struct index_state *istate);
+void release_index(struct index_state *istate);
+
 /* Name hashing */
 int test_lazy_init_name_hash(struct index_state *istate, int try_threaded);
 void add_name_hash(struct index_state *istate, struct cache_entry *ce);