From 1cc7887ffbb21ee6fbad1fa106ff3f981153ef3d Mon Sep 17 00:00:00 2001
From: Asias He <asias@scylladb.com>
Date: Wed, 9 Dec 2015 10:57:40 +0800
Subject: [PATCH] token_metadata: Do nothing if tokens is empty.

When replacing a node, we might ignore the tokens so that the tokens is
empty. In this case, we will have

   std::unordered_map<inet_address, std::unordered_set<token>> = {ip, {}}

passed to token_metadata::update_normal_tokens(std::unordered_map<inet_address,
std::unordered_set<token>>& endpoint_tokens)

and hit the assert

   assert(!tokens.empty());
---
 locator/token_metadata.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/locator/token_metadata.cc b/locator/token_metadata.cc
index 2e27a7e32e..55ddcc5ea1 100644
--- a/locator/token_metadata.cc
+++ b/locator/token_metadata.cc
@@ -81,6 +81,9 @@ void token_metadata::update_normal_token(token t, inet_address endpoint)
 }
 
 void token_metadata::update_normal_tokens(std::unordered_set<token> tokens, inet_address endpoint) {
+    if (tokens.empty()) {
+        return;
+    }
     std::unordered_map<inet_address, std::unordered_set<token>> endpoint_tokens ({{endpoint, tokens}});
     update_normal_tokens(endpoint_tokens);
 }