From 551980ccd4c2735cd7b1e00caa1fd53528ae7d7e Mon Sep 17 00:00:00 2001
From: robot-clickhouse <robot-clickhouse@users.noreply.github.com>
Date: Fri, 2 Jun 2023 18:06:03 +0000
Subject: [PATCH] Backport #50177 to 23.4: Fix broken index analysis when
 binary operator contains a null constant argument

---
 src/Storages/MergeTree/KeyCondition.cpp              |  4 ++++
 ...ndex_analysis_binary_operator_with_null.reference |  0
 ...2746_index_analysis_binary_operator_with_null.sql | 12 ++++++++++++
 3 files changed, 16 insertions(+)
 create mode 100644 tests/queries/0_stateless/02746_index_analysis_binary_operator_with_null.reference
 create mode 100644 tests/queries/0_stateless/02746_index_analysis_binary_operator_with_null.sql

diff --git a/src/Storages/MergeTree/KeyCondition.cpp b/src/Storages/MergeTree/KeyCondition.cpp
index 5d961425469a..dd6b83b13f71 100644
--- a/src/Storages/MergeTree/KeyCondition.cpp
+++ b/src/Storages/MergeTree/KeyCondition.cpp
@@ -1334,6 +1334,10 @@ bool KeyCondition::isKeyPossiblyWrappedByMonotonicFunctions(
                 arguments.push_back(const_arg);
                 kind = FunctionWithOptionalConstArg::Kind::RIGHT_CONST;
             }
+
+            /// If constant arg of binary operator is NULL, there will be no monotonicity.
+            if (const_arg.column->isNullAt(0))
+                return false;
         }
         else
             arguments.push_back({ nullptr, key_column_type, "" });
diff --git a/tests/queries/0_stateless/02746_index_analysis_binary_operator_with_null.reference b/tests/queries/0_stateless/02746_index_analysis_binary_operator_with_null.reference
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/tests/queries/0_stateless/02746_index_analysis_binary_operator_with_null.sql b/tests/queries/0_stateless/02746_index_analysis_binary_operator_with_null.sql
new file mode 100644
index 000000000000..f9613735bbf8
--- /dev/null
+++ b/tests/queries/0_stateless/02746_index_analysis_binary_operator_with_null.sql
@@ -0,0 +1,12 @@
+drop table if exists tab;
+
+create table tab (x DateTime) engine MergeTree order by x;
+
+SELECT toDateTime(65537, toDateTime(NULL), NULL)
+FROM tab
+WHERE ((x + CAST('1', 'Nullable(UInt8)')) <= 2) AND ((x + CAST('', 'Nullable(UInt8)')) <= 256)
+ORDER BY
+    toDateTime(toDateTime(-2, NULL, NULL) + 100.0001, NULL, -2, NULL) DESC NULLS LAST,
+    x ASC NULLS LAST;
+
+drop table tab;