[fix](delete) normalize DeleteSubPredicatePB operator on read path

be/src/storage/delete/delete_handler.cpp

@@ -225,7 +225,7 @@ std::string construct_sub_predicate(const TCondition& condition) {
 }
 
 // make operators from FE adaptive to BE
-std::string trans_op(const std::string& opt) {
+std::string trans_op(const std::string& opt, const std::string& condition_value = "") {
     std::string op = string(opt);
     if (op == "<") {
         op += "<";
@@ -237,6 +237,8 @@ std::string trans_op(const std::string& opt) {
             op = "=";
         } else if (op == "!*=") {
             op = "!=";
+        } else if (op == "<=>") {
+            op = iequal(condition_value, "NULL") ? "IS" : "=";
         }
     }
     return op;
@@ -487,7 +489,8 @@ DeleteHandler::ConditionParseResult DeleteHandler::parse_condition(
     }
     res.column_name = sub_cond.column_name();
     res.value_str.push_back(sub_cond.cond_value());
-    res.condition_op = parse_condition_op(sub_cond.op(), res.value_str);
+    auto norm_op = trans_op(sub_cond.op(), sub_cond.cond_value());
+    res.condition_op = parse_condition_op(norm_op, res.value_str);
     return res;
 }
 

regression-test/data/delete_p0/test_delete_nullsafe_eq.out

@@ -0,0 +1,3 @@
+-- This file is automatically generated. You should know what you did if you want to edit this
+-- !after_delete --
+2	20

regression-test/suites/delete_p0/test_delete_nullsafe_eq.groovy

@@ -0,0 +1,45 @@
+// 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_delete_nullsafe_eq", "delete_p0") {
+    sql "DROP TABLE IF EXISTS test_delete_nullsafe_eq"
+
+    sql """
+        CREATE TABLE test_delete_nullsafe_eq (
+            k1 INT,
+            v1 INT
+        )
+        DUPLICATE KEY(k1)
+        DISTRIBUTED BY HASH(k1) BUCKETS 1
+        PROPERTIES(
+            "replication_num" = "1",
+            "disable_auto_compaction" = "true"
+        )
+    """
+
+    sql """INSERT INTO test_delete_nullsafe_eq VALUES (1, 10), (2, 20)"""
+
+    try {
+        sql """SET delete_without_partition = true"""
+        sql """DELETE FROM test_delete_nullsafe_eq WHERE k1 <=> 1"""
+        sql """SYNC"""
+
+        order_qt_after_delete """SELECT * FROM test_delete_nullsafe_eq ORDER BY k1"""
+    } finally {
+        sql """SET delete_without_partition = false"""
+    }
+}