From fe8c4d64e434cacd4ceef34faa9005129f2190a5 Mon Sep 17 00:00:00 2001
From: Alexey Milovidov <milovidov@yandex-team.ru>
Date: Thu, 19 Jul 2018 23:51:03 +0300
Subject: [PATCH] Better fix #2660

---
 dbms/src/Parsers/ExpressionElementParsers.cpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/dbms/src/Parsers/ExpressionElementParsers.cpp b/dbms/src/Parsers/ExpressionElementParsers.cpp
index 9a199a6839ef..7595d3044c9e 100644
--- a/dbms/src/Parsers/ExpressionElementParsers.cpp
+++ b/dbms/src/Parsers/ExpressionElementParsers.cpp
@@ -1,6 +1,8 @@
 #include <errno.h>
 #include <cstdlib>
 
+#include <Poco/String.h>
+
 #include <IO/ReadHelpers.h>
 #include <IO/ReadBufferFromMemory.h>
 
@@ -236,6 +238,17 @@ bool ParserFunction::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
             , ErrorCodes::SYNTAX_ERROR);
     }
 
+    /// Temporary compatibility fix for Yandex.Metrika.
+    /// When we have a query with
+    ///  cast(x, 'Type')
+    /// when cast is not in uppercase and when expression is written as a function, not as operator like cast(x AS Type)
+    /// and newer ClickHouse server (1.1.54388) interacts with older ClickHouse server (1.1.54381) in distributed query,
+    /// then exception was thrown.
+
+    auto & identifier_concrete = typeid_cast<ASTIdentifier &>(*identifier);
+    if (Poco::toLower(identifier_concrete.name) == "cast")
+        identifier_concrete.name = "CAST";
+
     /// The parametric aggregate function has two lists (parameters and arguments) in parentheses. Example: quantile(0.9)(x).
     if (pos->type == TokenType::OpeningRoundBracket)
     {