Check if ART is shrunken when checking if r64 is shrunken

Author: SLieve

include/roaring/art/art.h

@@ -205,6 +205,11 @@ bool art_iterator_erase(art_iterator_t *iterator, art_val_t *erased_val);
  */
 size_t art_shrink_to_fit(art_t *art);
 
+/**
+ * Returns true if the ART has no unused elements.
+ */
+bool art_is_shrunken(const art_t *art);
+
 /**
  * Returns the serialized size in bytes.
  * Requires `art_shrink_to_fit` to be called first.

src/art/art.c

@@ -1794,19 +1794,6 @@ static void art_shrink_at(art_t *art, art_ref_t ref) {
     }
 }
 
-static bool art_is_shrunken(const art_t *art) {
-    return art->first_free[CROARING_ART_LEAF_TYPE] ==
-               art->capacities[CROARING_ART_LEAF_TYPE] &&
-           art->first_free[CROARING_ART_NODE4_TYPE] ==
-               art->capacities[CROARING_ART_NODE4_TYPE] &&
-           art->first_free[CROARING_ART_NODE16_TYPE] ==
-               art->capacities[CROARING_ART_NODE16_TYPE] &&
-           art->first_free[CROARING_ART_NODE48_TYPE] ==
-               art->capacities[CROARING_ART_NODE48_TYPE] &&
-           art->first_free[CROARING_ART_NODE256_TYPE] ==
-               art->capacities[CROARING_ART_NODE256_TYPE];
-}
-
 void art_init_cleared(art_t *art) {
     art->root = CROARING_ART_NULL_REF;
     memset(art->first_free, 0, sizeof(art->first_free));
@@ -1829,6 +1816,16 @@ size_t art_shrink_to_fit(art_t *art) {
     return art_shrink_node_arrays(art);
 }
 
+bool art_is_shrunken(const art_t *art) {
+    for (art_typecode_t t = CROARING_ART_MIN_TYPE; t <= CROARING_ART_MAX_TYPE;
+         ++t) {
+        if (art->first_free[t] != art->capacities[t]) {
+            return false;
+        }
+    }
+    return true;
+}
+
 art_val_t *art_insert(art_t *art, const art_key_chunk_t *key, art_val_t val) {
     art_ref_t leaf = art_leaf_create(art, key, val);
     if (art->root == CROARING_ART_NULL_REF) {

src/roaring64.c

@@ -964,7 +964,7 @@ static void move_to_shrink(roaring64_bitmap_t *r, leaf_t *leaf) {
 }
 
 static inline bool is_shrunken(const roaring64_bitmap_t *r) {
-    return r->first_free == r->capacity;
+    return art_is_shrunken(&r->art) && r->first_free == r->capacity;
 }
 
 size_t roaring64_bitmap_shrink_to_fit(roaring64_bitmap_t *r) {