From 86053c754f9354cdf1469cec8441c285ed14ba0a Mon Sep 17 00:00:00 2001
From: Alexey Milovidov <milovidov@yandex-team.ru>
Date: Thu, 14 Jun 2018 22:54:11 +0300
Subject: [PATCH] Fixed warning on platforms where char is unsigned
 [#CLICKHOUSE-2]

---
 dbms/src/Common/StringUtils/StringUtils.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dbms/src/Common/StringUtils/StringUtils.h b/dbms/src/Common/StringUtils/StringUtils.h
index 8043b88a89e..db7e8cc89f7 100644
--- a/dbms/src/Common/StringUtils/StringUtils.h
+++ b/dbms/src/Common/StringUtils/StringUtils.h
@@ -109,7 +109,7 @@ inline bool isWhitespaceASCII(char c)
 
 inline bool isControlASCII(char c)
 {
-    return c >= 0 && c <= 31;
+    return static_cast<unsigned char>(c) <= 31;
 }
 
 /// Works assuming isAlphaASCII.