From d712748304f4201e1fa0d6258e23d927796bedcd Mon Sep 17 00:00:00 2001
From: Maksim Kita <maksim-kita@yandex-team.ru>
Date: Fri, 22 Jan 2021 16:24:51 +0300
Subject: [PATCH] Function accurateCastOrNull fixed unitialized values for
 numeric cast

---
 src/Functions/FunctionsConversion.h               |  8 ++++++++
 tests/performance/casts.xml                       | 15 +++++++++++++++
 .../01556_accurate_cast_or_null.reference         |  2 ++
 .../0_stateless/01556_accurate_cast_or_null.sql   |  2 ++
 4 files changed, 27 insertions(+)
 create mode 100644 tests/performance/casts.xml

diff --git a/src/Functions/FunctionsConversion.h b/src/Functions/FunctionsConversion.h
index 978fa0a79d8..0e162fc2469 100644
--- a/src/Functions/FunctionsConversion.h
+++ b/src/Functions/FunctionsConversion.h
@@ -188,7 +188,10 @@ struct ConvertImpl
                     (std::is_same_v<FromFieldType, UInt128> || std::is_same_v<ToFieldType, UInt128>))
                 {
                     if constexpr (std::is_same_v<Additions, AccurateOrNullConvertStrategyAdditions>)
+                    {
+                        vec_to[i] = 0;
                         (*vec_null_map_to)[i] = true;
+                    }
                     else
                         throw Exception("Unexpected UInt128 to big int conversion", ErrorCodes::NOT_IMPLEMENTED);
                 }
@@ -215,7 +218,10 @@ struct ConvertImpl
                             if (convert_result)
                                 vec_to[i] = result;
                             else
+                            {
+                                vec_to[i] = static_cast<ToFieldType>(0);
                                 (*vec_null_map_to)[i] = true;
+                            }
                         }
                         else
                         {
@@ -238,6 +244,7 @@ struct ConvertImpl
                             {
                                 if constexpr (std::is_same_v<Additions, AccurateOrNullConvertStrategyAdditions>)
                                 {
+                                    vec_to[i] = 0;
                                     (*vec_null_map_to)[i] = true;
                                     continue;
                                 }
@@ -255,6 +262,7 @@ struct ConvertImpl
                             {
                                 if (std::is_same_v<Additions, AccurateOrNullConvertStrategyAdditions>)
                                 {
+                                    vec_to[i] = 0;
                                     (*vec_null_map_to)[i] = true;
                                 }
                                 else
diff --git a/tests/performance/casts.xml b/tests/performance/casts.xml
new file mode 100644
index 00000000000..17a1c774353
--- /dev/null
+++ b/tests/performance/casts.xml
@@ -0,0 +1,15 @@
+<test max_ignored_relative_change="0.2">
+    <settings>
+        <max_memory_usage>15G</max_memory_usage>
+    </settings>
+
+    <create_query>CREATE TABLE t (x UInt64) ENGINE = Memory</create_query>
+    <!-- use less threads to save memory -->
+    <fill_query>INSERT INTO t SELECT number AS x FROM numbers_mt(200000000) SETTINGS max_threads = 8</fill_query>
+    <drop_query>DROP TABLE IF EXISTS t</drop_query>
+
+    <query>SELECT cast(x, 'Int64'), cast(x, 'Int128'), cast(x, 'Int256'), cast(x, 'String'), cast(x, 'Decimal64(8)') FROM t FORMAT Null</query>
+    <query>SELECT accurateCast(x, 'Int64'), accurateCast(x, 'Int128'), accurateCast(x, 'Int256'), accurateCast(x, 'String'), accurateCast(x, 'Decimal64(8)') FROM t FORMAT Null</query>
+    <query>SELECT accurateCastOrNull(x, 'Int64'), accurateCastOrNull(x, 'Int128'), accurateCastOrNull(x, 'Int256'), accurateCastOrNull(x, 'String'), accurateCastOrNull(x, 'Decimal64(8)') FROM t FORMAT Null</query>
+
+</test>
diff --git a/tests/queries/0_stateless/01556_accurate_cast_or_null.reference b/tests/queries/0_stateless/01556_accurate_cast_or_null.reference
index 4287c755c3f..3b27dd2e2e1 100644
--- a/tests/queries/0_stateless/01556_accurate_cast_or_null.reference
+++ b/tests/queries/0_stateless/01556_accurate_cast_or_null.reference
@@ -28,3 +28,5 @@
 \N
 \N
 \N
+127
+\N
diff --git a/tests/queries/0_stateless/01556_accurate_cast_or_null.sql b/tests/queries/0_stateless/01556_accurate_cast_or_null.sql
index b11ed5939fa..b45bbe35662 100644
--- a/tests/queries/0_stateless/01556_accurate_cast_or_null.sql
+++ b/tests/queries/0_stateless/01556_accurate_cast_or_null.sql
@@ -33,3 +33,5 @@ SELECT accurateCastOrNull(inf, 'UInt64');
 SELECT accurateCastOrNull(inf, 'UInt256');
 SELECT accurateCastOrNull(nan, 'UInt64');
 SELECT accurateCastOrNull(nan, 'UInt256');
+
+SELECT accurateCastOrNull(number + 127, 'Int8') AS x FROM numbers (2) ORDER BY x;