From 6d42868283cd8eb6c920932412e08a1e774dcf6f Mon Sep 17 00:00:00 2001
From: Andrey Mironov <hertz@yandex-team.ru>
Date: Thu, 19 Nov 2015 09:50:05 +0300
Subject: [PATCH] dbms: ClickHouseDictionarySource: check that key is present
 before dereferencing [#METR-18945]

---
 dbms/include/DB/Dictionaries/ClickHouseDictionarySource.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/dbms/include/DB/Dictionaries/ClickHouseDictionarySource.h b/dbms/include/DB/Dictionaries/ClickHouseDictionarySource.h
index 1122df10976..3da4b0a0252 100644
--- a/dbms/include/DB/Dictionaries/ClickHouseDictionarySource.h
+++ b/dbms/include/DB/Dictionaries/ClickHouseDictionarySource.h
@@ -42,7 +42,7 @@ public:
 			  "ClickHouseDictionarySource")
 		  },
 		  load_all_query{composeLoadAllQuery()},
-		  key_tuple_definition{composeKeyTupleDefinition()}
+		  key_tuple_definition{dict_struct.key ? composeKeyTupleDefinition() : std::string{}}
 	{}
 
 	/// copy-constructor is provided in order to support cloneability
@@ -318,6 +318,9 @@ private:
 
 	std::string composeKeyTupleDefinition() const
 	{
+		if (!dict_struct.key)
+			throw Exception{"Composite key required for method", ErrorCodes::UNSUPPORTED_METHOD};
+
 		std::string result{"("};
 
 		auto first = true;