[FLINK-38537][runtime] Fix the bug that can't compare correctly Double.NaN related attributes in StatsSummaryDto#equals method

Author: RocMarshal

flink-runtime/src/main/java/org/apache/flink/runtime/rest/messages/util/stats/StatsSummaryDto.java

@@ -149,11 +149,11 @@ public boolean equals(Object o) {
         return minimum == that.minimum
                 && maximum == that.maximum
                 && average == that.average
-                && p50 == that.p50
-                && p90 == that.p90
-                && p95 == that.p95
-                && p99 == that.p99
-                && p999 == that.p999;
+                && Double.compare(p50, that.p50) == 0
+                && Double.compare(p90, that.p90) == 0
+                && Double.compare(p95, that.p95) == 0
+                && Double.compare(p99, that.p99) == 0
+                && Double.compare(p999, that.p999) == 0;
     }
 
     @Override

flink-runtime/src/test/java/org/apache/flink/runtime/rest/messages/util/stats/StatsSummaryDtoTest.java

@@ -0,0 +1,59 @@
+/*
+ * 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.
+ */
+
+package org.apache.flink.runtime.rest.messages.util.stats;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/** Test for {@link org.apache.flink.runtime.rest.messages.util.stats.StatsSummaryDto}. */
+class StatsSummaryDtoTest {
+    @Test
+    void testEquals() {
+        StatsSummaryDto dtoWithoutNaNDoubleValue =
+                new StatsSummaryDto(1L, 1L, 1L, 0d, 0d, 0d, 0d, 0d);
+        StatsSummaryDto dtoWithANaNDoubleValue =
+                new StatsSummaryDto(1L, 1L, 1L, 0d, 0d, 0d, 0d, Double.NaN);
+        assertThat(dtoWithoutNaNDoubleValue).isNotEqualTo(dtoWithANaNDoubleValue);
+        assertThat(dtoWithANaNDoubleValue).isNotEqualTo(dtoWithoutNaNDoubleValue);
+
+        StatsSummaryDto dtoWithAllNaNDouble1 =
+                new StatsSummaryDto(
+                        1L, 1L, 1L, Double.NaN, Double.NaN, Double.NaN, Double.NaN, Double.NaN);
+        StatsSummaryDto dtoWithAllNaNDouble2 =
+                new StatsSummaryDto(
+                        1L, 1L, 1L, Double.NaN, Double.NaN, Double.NaN, Double.NaN, Double.NaN);
+        assertThat(dtoWithAllNaNDouble1).isEqualTo(dtoWithAllNaNDouble2);
+        assertThat(dtoWithAllNaNDouble2).isEqualTo(dtoWithAllNaNDouble1);
+
+        StatsSummaryDto dtoWithoutNaNDoubleValue1 =
+                new StatsSummaryDto(1L, 1L, 1L, 0d, 0d, 0d, 0d, 0d);
+        StatsSummaryDto dtoWithoutNaNDoubleValue2 =
+                new StatsSummaryDto(1L, 1L, 1L, 0d, 0d, 0d, 0d, 0d);
+        assertThat(dtoWithoutNaNDoubleValue1).isEqualTo(dtoWithoutNaNDoubleValue2);
+        assertThat(dtoWithoutNaNDoubleValue2).isEqualTo(dtoWithoutNaNDoubleValue1);
+
+        StatsSummaryDto dtoWithoutNaNDoubleValue3 =
+                new StatsSummaryDto(1L, 1L, 1L, 0d, 1d, 0d, 0d, 0d);
+        StatsSummaryDto dtoWithoutNaNDoubleValue4 =
+                new StatsSummaryDto(1L, 1L, 1L, 0d, 0d, 0d, 0d, 0d);
+        assertThat(dtoWithoutNaNDoubleValue3).isNotEqualTo(dtoWithoutNaNDoubleValue4);
+        assertThat(dtoWithoutNaNDoubleValue4).isNotEqualTo(dtoWithoutNaNDoubleValue3);
+    }
+}