From a2ff9391ad0c099cd90263e0ff53c12804ca0730 Mon Sep 17 00:00:00 2001
From: chertus <chertus@gmail.com>
Date: Thu, 14 Feb 2019 17:25:55 +0300
Subject: [PATCH] fix UB

---
 dbms/src/Interpreters/TranslateQualifiedNamesVisitor.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/dbms/src/Interpreters/TranslateQualifiedNamesVisitor.cpp b/dbms/src/Interpreters/TranslateQualifiedNamesVisitor.cpp
index febc9753366..35aa9461709 100644
--- a/dbms/src/Interpreters/TranslateQualifiedNamesVisitor.cpp
+++ b/dbms/src/Interpreters/TranslateQualifiedNamesVisitor.cpp
@@ -75,7 +75,8 @@ std::vector<ASTPtr *> TranslateQualifiedNamesMatcher::visit(ASTIdentifier & iden
         /// In case if column from the joined table are in source columns, change it's name to qualified.
         if (best_table_pos && data.source_columns.count(identifier.shortName()))
             IdentifierSemantic::setNeedLongName(identifier, true);
-        IdentifierSemantic::setColumnNormalName(identifier, data.tables[best_table_pos].first);
+        if (!data.tables.empty())
+            IdentifierSemantic::setColumnNormalName(identifier, data.tables[best_table_pos].first);
     }
 
     return {};