fix test_dht to take into account the slightly more relaxed semantics of routing_table::find_node

src/kademlia/node_id.cpp

@@ -181,5 +181,14 @@ bool matching_prefix(node_entry const& n, int mask, int prefix, int bucket_index
 	return (id[0] & mask) == prefix;
 }
 
+node_id generate_prefix_mask(int bits)
+{
+	node_id mask(0);
+	int b = 0;
+	for (; b < bits - 7; b += 8) mask[b/8] |= 0xff;
+	mask[b/8] |= 0xff << (8 - (bits&7));
+	return mask;
+}
+
 } }  // namespace libtorrent::dht
 

src/kademlia/routing_table.cpp

@@ -290,8 +290,7 @@ bool routing_table::need_refresh(node_id& target) const
 	// generate a random node_id within the given bucket
 	target = generate_random_id();
 	int num_bits = std::distance(m_buckets.begin(), i) + 1;
-	node_id mask(0);
-	for (int i = 0; i < num_bits; ++i) mask[i/8] |= 0x80 >> (i&7);
+	node_id mask = generate_prefix_mask(num_bits);
 
 	// target = (target & ~mask) | (root & mask)
 	node_id root = m_id;