From 5bb0cde59c4de1f89d2c7b00316c952302f32ed8 Mon Sep 17 00:00:00 2001
From: chertus <chertus@gmail.com>
Date: Wed, 7 Aug 2019 16:53:46 +0300
Subject: [PATCH] hotfix for Decimal.compareAt

---
 dbms/src/Columns/ColumnDecimal.cpp                 |  2 +-
 .../0_stateless/00880_decimal_in_key.reference     |  2 ++
 .../queries/0_stateless/00880_decimal_in_key.sql   | 14 ++++++++++++++
 3 files changed, 17 insertions(+), 1 deletion(-)
 create mode 100644 dbms/tests/queries/0_stateless/00880_decimal_in_key.reference
 create mode 100644 dbms/tests/queries/0_stateless/00880_decimal_in_key.sql

diff --git a/dbms/src/Columns/ColumnDecimal.cpp b/dbms/src/Columns/ColumnDecimal.cpp
index 55c22884144..73b0ee282d6 100644
--- a/dbms/src/Columns/ColumnDecimal.cpp
+++ b/dbms/src/Columns/ColumnDecimal.cpp
@@ -26,7 +26,7 @@ namespace ErrorCodes
 template <typename T>
 int ColumnDecimal<T>::compareAt(size_t n, size_t m, const IColumn & rhs_, int) const
 {
-    auto other = static_cast<const Self &>(rhs_);
+    auto & other = static_cast<const Self &>(rhs_);
     const T & a = data[n];
     const T & b = other.data[m];
 
diff --git a/dbms/tests/queries/0_stateless/00880_decimal_in_key.reference b/dbms/tests/queries/0_stateless/00880_decimal_in_key.reference
new file mode 100644
index 00000000000..fcd78da1283
--- /dev/null
+++ b/dbms/tests/queries/0_stateless/00880_decimal_in_key.reference
@@ -0,0 +1,2 @@
+1000000
+1000000
diff --git a/dbms/tests/queries/0_stateless/00880_decimal_in_key.sql b/dbms/tests/queries/0_stateless/00880_decimal_in_key.sql
new file mode 100644
index 00000000000..44edf725a41
--- /dev/null
+++ b/dbms/tests/queries/0_stateless/00880_decimal_in_key.sql
@@ -0,0 +1,14 @@
+DROP TABLE IF EXISTS t1;
+DROP TABLE IF EXISTS t2;
+
+CREATE TABLE t1 (str String, dec Decimal64(8)) ENGINE = MergeTree ORDER BY str;
+CREATE TABLE t2 (str String, dec Decimal64(8)) ENGINE = MergeTree ORDER BY dec;
+
+INSERT INTO t1 SELECT toString(number), toDecimal64(number, 8) FROM system.numbers LIMIT 1000000;
+SELECT count() FROM t1;
+
+INSERT INTO t2 SELECT toString(number), toDecimal64(number, 8) FROM system.numbers LIMIT 1000000;
+SELECT count() FROM t2;
+
+DROP TABLE t1;
+DROP TABLE t2;