Backport #90557 to 25.10: Fix logical error caused by type mismatch in equals function

robot-clickhouse · robot-clickhouse · commit e34e5726c951 · 2025-11-21T17:11:31.000Z
diff --git a/src/Functions/FunctionsComparison.h b/src/Functions/FunctionsComparison.h
@@ -1232,6 +1232,7 @@ class FunctionComparison : public IFunction
 
             bool has_nullable = false;
             bool has_null = false;
+            bool has_nothing = false;
 
             const DataTypeTuple * any_tuple = left_tuple ? left_tuple : right_tuple;
             size_t size = any_tuple->getElements().size();
@@ -1245,9 +1246,17 @@ class FunctionComparison : public IFunction
                     element_type = func->build(args)->getResultType();
                 }
                 has_nullable = has_nullable || element_type->isNullable() || isDynamic(element_type);
+
+                /// Nullable(Nothing)
                 has_null = has_null || element_type->onlyNull();
+
+                /// Nothing
+                has_nothing = has_nothing || isNothing(element_type);
             }
 
+            if (has_nothing)
+                return std::make_shared<DataTypeNothing>();
+
             /// If any element comparison is nullable, return type will also be nullable.
             /// We useDefaultImplementationForNulls, but it doesn't work for tuples.
             if (has_null)
diff --git a/tests/queries/0_stateless/03724_filter_assume_not_null_materialize.reference b/tests/queries/0_stateless/03724_filter_assume_not_null_materialize.reference
diff --git a/tests/queries/0_stateless/03724_filter_assume_not_null_materialize.sql b/tests/queries/0_stateless/03724_filter_assume_not_null_materialize.sql
@@ -0,0 +1,19 @@
+SET allow_not_comparable_types_in_comparison_functions = 0;
+
+SELECT (assumeNotNull((NULL)), 1); -- { serverError ILLEGAL_COLUMN }
+
+SELECT (assumeNotNull(materialize(NULL)), 1); -- { serverError ILLEGAL_COLUMN }
+
+SELECT 1 WHERE (assumeNotNull(NULL), 1) = (1, 1); -- { serverError ILLEGAL_COLUMN }
+
+SELECT 1 WHERE (assumeNotNull(materialize(NULL)), 1) = (1, 1); -- { serverError ILLEGAL_TYPE_OF_COLUMN_FOR_FILTER }
+
+SET allow_not_comparable_types_in_comparison_functions = 1;
+
+SELECT (assumeNotNull((NULL)), 1); -- { serverError ILLEGAL_COLUMN }
+
+SELECT (assumeNotNull(materialize(NULL)), 1); -- { serverError ILLEGAL_COLUMN }
+
+SELECT 1 WHERE (assumeNotNull(NULL), 1) = (1, 1); -- { serverError ILLEGAL_COLUMN }
+
+SELECT 1 WHERE (assumeNotNull(materialize(NULL)), 1) = (1, 1); -- { serverError ILLEGAL_TYPE_OF_COLUMN_FOR_FILTER }
diff --git a/tests/queries/0_stateless/03725_empty_tuple_some_limit_with_ties_distinct.reference b/tests/queries/0_stateless/03725_empty_tuple_some_limit_with_ties_distinct.reference
@@ -0,0 +1,5 @@
+()
+\N	1.1
+\N	2.2
+1	3.3
+2	4.4
diff --git a/tests/queries/0_stateless/03725_empty_tuple_some_limit_with_ties_distinct.sql b/tests/queries/0_stateless/03725_empty_tuple_some_limit_with_ties_distinct.sql
@@ -0,0 +1,9 @@
+SELECT () ORDER BY 1 LIMIT 1 WITH TIES;
+
+DROP TABLE IF EXISTS t0;
+
+CREATE TABLE t0 (v1 Nullable(Int8), v2 Decimal(18,4)) ENGINE = MergeTree() ORDER BY tuple();
+SELECT DISTINCT TOP 1 WITH TIES * FROM t0 ORDER BY tuple();
+
+INSERT INTO t0 VALUES (NULL, 1.1), (NULL, 2.2), (1, 3.3), (2, 4.4);
+SELECT DISTINCT TOP 1 WITH TIES * FROM t0 ORDER BY tuple();

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +()
 +\N	1.1
 +\N	2.2
 +1	3.3
 +2	4.4