Fixing issue 245.

include/roaring/containers/containers.h

@@ -2270,8 +2270,7 @@ static inline void *container_add_range(void *container, uint8_t type,
                 *result_type = RUN_CONTAINER_TYPE_CODE;
                 return run;
             } else {
-                *result_type = BITSET_CONTAINER_TYPE_CODE;
-                return bitset_container_from_run_range(run, min, max);
+                return container_from_run_range(run, min, max, result_type);
             }
         }
         default:

include/roaring/containers/convert.h

@@ -50,10 +50,10 @@ void *convert_run_to_efficient_container_and_free(run_container_t *c,
                                                   uint8_t *typecode_after);
 
 /**
- * Create new bitset container which is a union of run container and
+ * Create new container which is a union of run container and
  * range [min, max]. Caller is responsible for freeing run container.
  */
-bitset_container_t *bitset_container_from_run_range(const run_container_t *run,
-                                                    uint32_t min, uint32_t max);
+void *container_from_run_range(const run_container_t *run,
+                                                    uint32_t min, uint32_t max, uint8_t *typecode_after);
 
 #endif /* INCLUDE_CONTAINERS_CONVERT_H_ */

src/containers/convert.c

@@ -292,10 +292,11 @@ void *convert_run_optimize(void *c, uint8_t typecode_original,
         return NULL;
     }
 }
-
-bitset_container_t *bitset_container_from_run_range(const run_container_t *run,
-                                                    uint32_t min, uint32_t max) {
+void *container_from_run_range(const run_container_t *run,
+                                                    uint32_t min, uint32_t max, uint8_t *typecode_after) {
+    // We expect most of the time to end up with a bitset container
     bitset_container_t *bitset = bitset_container_create();
+    *typecode_after = BITSET_CONTAINER_TYPE_CODE;
     int32_t union_cardinality = 0;
     for (int32_t i = 0; i < run->n_runs; ++i) {
         uint32_t rle_min = run->runs[i].value;
@@ -307,5 +308,12 @@ bitset_container_t *bitset_container_from_run_range(const run_container_t *run,
     union_cardinality -= bitset_lenrange_cardinality(bitset->array, min, max-min);
     bitset_set_lenrange(bitset->array, min, max - min);
     bitset->cardinality = union_cardinality;
+    if(bitset->cardinality <= DEFAULT_MAX_SIZE) {
+        // we need to convert to an array container
+        array_container_t * array = array_container_from_bitset(bitset);
+        *typecode_after = ARRAY_CONTAINER_TYPE_CODE;
+        bitset_container_free(bitset);
+        return array;
+    }
     return bitset;
 }

tests/toplevel_unit.c

@@ -84,6 +84,51 @@ void can_copy_empty(bool copy_on_write) {
     roaring_bitmap_free(bm2);
 }
 
+
+
+
+
+bool check_serialization(roaring_bitmap_t *bitmap) {
+    const int32_t size = roaring_bitmap_portable_size_in_bytes(bitmap);
+    char *data = (char *)malloc(size);
+    roaring_bitmap_portable_serialize(bitmap, data);
+    roaring_bitmap_t *deserializedBitmap = roaring_bitmap_portable_deserialize(data);
+    bool ret = roaring_bitmap_equals(bitmap, deserializedBitmap);
+    roaring_bitmap_free(deserializedBitmap);
+    free(data);
+    return ret;
+}
+
+
+void issue245() {
+    roaring_bitmap_t *bitmap = roaring_bitmap_create();
+    const uint32_t targetEntries = 2048;
+    const int32_t runLength = 8;
+    int32_t offset = 0;
+    // Add a single run more than 2 extents longs.
+    roaring_bitmap_add_range_closed(bitmap, offset, offset + runLength);
+    offset += runLength + 2;
+    // Add 2047 non-contiguous bits.
+    for (uint32_t count = 1; count < targetEntries; count++, offset += 2) {
+        roaring_bitmap_add_range_closed(bitmap, offset, offset);
+    }
+
+    if (!check_serialization(bitmap)) {
+        printf("Bitmaps do not match at 2048 entries\n");
+        abort();
+    }
+
+    // Add one more, forcing it to become a bitset
+    offset += 2;
+    roaring_bitmap_add_range_closed(bitmap, offset, offset);
+
+    if (!check_serialization(bitmap)) {
+        printf("Bitmaps do not match at 2049 entries\n");
+        abort();
+    }
+    roaring_bitmap_free(bitmap);
+}
+
 void issue208() {
     roaring_bitmap_t *r = roaring_bitmap_create();
     for (uint32_t i = 1; i < 8194; i+=2) {
@@ -4068,6 +4113,7 @@ void test_frozen_serialization_max_containers() {
 
 int main() {
     const struct CMUnitTest tests[] = {
+        cmocka_unit_test(issue245),
         cmocka_unit_test(issue208),
         cmocka_unit_test(issue208b),
         cmocka_unit_test(range_contains),