fix error for in Null

src/Analyzer/Passes/ConvertInToEqualPass.cpp

@@ -32,9 +32,12 @@ class ConvertInToEqualPassVisitor : public InDepthQueryTreeVisitorWithContext<Co
         auto * constant_node = args[1]->as<ConstantNode>();
         if (!column_node || !constant_node)
             return ;
+        // IN multiple values is not supported
         if (constant_node->getValue().getType() == Field::Types::Which::Tuple)
-            return;
-
+            return ;
+        // x IN null not equivalent to x = null
+        if (constant_node->hasSourceExpression() || constant_node->getValue().isNull())
+            return ;
         auto equal_resolver = createInternalFunctionEqualOverloadResolver();
         auto equal = std::make_shared<FunctionNode>("equals");
         QueryTreeNodes arguments{column_node->clone(), constant_node->clone()};

tests/queries/0_stateless/03013_optimize_in_to_equal.reference

@@ -1,5 +1,11 @@
 a	1
 -------------------
+0
+0
+0
+0
+0
+-------------------
 QUERY id: 0
   PROJECTION COLUMNS
     x String

tests/queries/0_stateless/03013_optimize_in_to_equal.sql

@@ -5,6 +5,8 @@ INSERT INTO test VALUES ('a', 1), ('b', 2), ('c', 3), ('d', 4), ('e', 5);
 
 select * from test where x in ('a') SETTINGS allow_experimental_analyzer = 1;
 select '-------------------';
+select x in Null from test;
+select '-------------------';
 explain query tree select * from test where x in ('a') SETTINGS allow_experimental_analyzer = 1;
 select '-------------------';
-explain query tree select * from test where x in ('a','b') SETTINGS allow_experimental_analyzer = 1;
+explain query tree select * from test where x in ('a','b') SETTINGS allow_experimental_analyzer = 1;