[bugfix](dict) fix coredump of dict colum range predicate when there is null value (#11967)

be/src/vec/columns/column_dictionary.h

@@ -296,7 +296,7 @@ public:
             return -2; // -1 is null code
         }
 
-        T get_null_code() { return -1; }
+        T get_null_code() const { return -1; }
 
         inline StringValue& get_value(T code) {
             return code >= _dict_data.size() ? _null_value : _dict_data[code];
@@ -391,7 +391,12 @@ public:
             }
         }
 
-        T convert_code(const T& code) const { return _code_convert_table[code]; }
+        T convert_code(const T& code) const {
+            if (get_null_code() == code) {
+                return code;
+            }
+            return _code_convert_table[code];
+        }
 
         size_t byte_size() { return _dict_data.size() * sizeof(_dict_data[0]); }
 

regression-test/data/correctness_p0/test_dict_range_predicate.out

@@ -0,0 +1,7 @@
+-- This file is automatically generated. You should know what you did if you want to edit this
+-- !select_default --
+4	d
+
+-- !select_default --
+1	a
+3	c

regression-test/suites/correctness_p0/test_dict_range_predicate.groovy

@@ -0,0 +1,47 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+ // or more contributor license agreements.  See the NOTICE file
+ // distributed with this work for additional information
+ // regarding copyright ownership.  The ASF licenses this file
+ // to you under the Apache License, Version 2.0 (the
+ // "License"); you may not use this file except in compliance
+ // with the License.  You may obtain a copy of the License at
+ //
+ //   http://www.apache.org/licenses/LICENSE-2.0
+ //
+ // Unless required by applicable law or agreed to in writing,
+ // software distributed under the License is distributed on an
+ // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ // KIND, either express or implied.  See the License for the
+ // specific language governing permissions and limitations
+ // under the License.
+
+ suite("test_dict_range_predicate") {
+     def tableName = "test_dict_range_predicate"
+
+     sql """ DROP TABLE IF EXISTS ${tableName} """
+     sql """
+        CREATE TABLE ${tableName}  (
+        `a` int,
+        `b` char(10)
+        ) ENGINE=OLAP
+        DUPLICATE KEY(`a`)
+        DISTRIBUTED BY HASH(`a`) BUCKETS 4
+        PROPERTIES (
+        "replication_allocation" = "tag.location.default: 1",
+        "in_memory" = "false",
+        "storage_format" = "V2"
+        );
+     """
+
+     sql "insert into ${tableName} values (1, 'a'), (2, null), (3, 'c'), (4, 'd');"
+
+     qt_select_default """ 
+      select *
+        from ${tableName} WHERE b > 'c' order by a
+    """
+
+     qt_select_default """ 
+      select *
+        from ${tableName} WHERE b <= 'c' order by a
+    """
+ }