rec_init_offsets_comp_ordinary(): Fix a bug

storage/innobase/include/page0cur.ic

@@ -280,6 +280,7 @@ page_cur_tuple_insert(
 	*offsets = rec_get_offsets(rec, index, *offsets,
 				   page_is_leaf(cursor->block->frame),
 				   ULINT_UNDEFINED, heap);
+	ut_ad(size == rec_offs_size(*offsets));
 
 	if (buf_block_get_page_zip(cursor->block)) {
 		rec = page_cur_insert_rec_zip(

storage/innobase/rem/rem0rec.cc

@@ -348,9 +348,7 @@ rec_init_offsets_comp_ordinary(
 		ut_ad(index->is_instant());
 		/* fall through */
 	case REC_LEAF_TEMP_INSTANT:
-		n_fields = n_core + rec_get_n_add_field(nulls)
-			+ (!index->table->instant
-			   || rec_is_metadata(rec, index));
+		n_fields = n_core + rec_get_n_add_field(nulls) + 1;
 		ut_ad(n_fields <= index->n_fields);
 		const ulint n_nullable = index->get_n_nullable(n_fields);
 		const ulint n_null_bytes = UT_BITS_IN_BYTES(n_nullable);