[CALCITE-5839] EnumerableInterpretable#StaticFieldDetector can overwr…

…ite its flag and return an incorrect result

core/src/main/java/org/apache/calcite/adapter/enumerable/EnumerableInterpretable.java

@@ -185,7 +185,7 @@ static class StaticFieldDetector extends VisitorImpl<Void> {
     boolean containsStaticField = false;
 
     @Override public Void visit(final FieldDeclaration fieldDeclaration) {
-      containsStaticField = (fieldDeclaration.modifier & Modifier.STATIC) != 0;
+      containsStaticField |= (fieldDeclaration.modifier & Modifier.STATIC) != 0;
       return containsStaticField ? null : super.visit(fieldDeclaration);
     }
   }

core/src/test/java/org/apache/calcite/adapter/enumerable/StaticFieldDetectorTest.java

@@ -0,0 +1,115 @@
+/*
+ * 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.calcite.adapter.enumerable;
+
+import org.apache.calcite.linq4j.tree.ClassDeclaration;
+import org.apache.calcite.linq4j.tree.Expressions;
+import org.apache.calcite.linq4j.tree.FieldDeclaration;
+
+import com.google.common.collect.ImmutableList;
+
+import org.junit.jupiter.api.Test;
+
+import java.lang.reflect.Modifier;
+import java.util.Arrays;
+
+import static org.hamcrest.CoreMatchers.is;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+/**
+ * Tests for {@link EnumerableInterpretable.StaticFieldDetector}.
+ */
+public final class StaticFieldDetectorTest {
+
+  @Test void testClassWithoutStaticFields() {
+    ClassDeclaration classDeclaration =
+        createClassDeclaration(
+            new FieldDeclaration(
+                Modifier.PUBLIC,
+                Expressions.parameter(int.class, "x"),
+                Expressions.constant(0)));
+
+    EnumerableInterpretable.StaticFieldDetector detector =
+        new EnumerableInterpretable.StaticFieldDetector();
+    classDeclaration.accept(detector);
+    assertThat(detector.containsStaticField, is(false));
+  }
+
+  @Test void testClassWithOnlyStaticFields() {
+    ClassDeclaration classDeclaration =
+        createClassDeclaration(
+            new FieldDeclaration(
+                Modifier.PUBLIC | Modifier.STATIC,
+                Expressions.parameter(int.class, "x"),
+                Expressions.constant(0)),
+            new FieldDeclaration(
+                Modifier.STATIC,
+                Expressions.parameter(int.class, "y"),
+                Expressions.constant(0)));
+
+    EnumerableInterpretable.StaticFieldDetector detector =
+        new EnumerableInterpretable.StaticFieldDetector();
+    classDeclaration.accept(detector);
+    assertThat(detector.containsStaticField, is(true));
+  }
+
+  @Test void testClassWithStaticAndNonStaticFields() {
+    ClassDeclaration classDeclaration =
+        createClassDeclaration(
+            new FieldDeclaration(
+                Modifier.PUBLIC | Modifier.STATIC,
+                Expressions.parameter(int.class, "x"),
+                Expressions.constant(0)),
+            new FieldDeclaration(
+                Modifier.PUBLIC,
+                Expressions.parameter(int.class, "y"),
+                Expressions.constant(0)));
+
+    EnumerableInterpretable.StaticFieldDetector detector =
+        new EnumerableInterpretable.StaticFieldDetector();
+    classDeclaration.accept(detector);
+    assertThat(detector.containsStaticField, is(true));
+  }
+
+  @Test void testClassWithNonStaticAndStaticFields() {
+    ClassDeclaration classDeclaration =
+        createClassDeclaration(
+            new FieldDeclaration(
+                Modifier.PUBLIC,
+                Expressions.parameter(int.class, "x"),
+                Expressions.constant(0)),
+            new FieldDeclaration(
+                Modifier.PUBLIC | Modifier.STATIC,
+                Expressions.parameter(int.class, "y"),
+                Expressions.constant(0)));
+
+    EnumerableInterpretable.StaticFieldDetector detector =
+        new EnumerableInterpretable.StaticFieldDetector();
+    classDeclaration.accept(detector);
+    assertThat(detector.containsStaticField, is(true));
+  }
+
+  private static ClassDeclaration createClassDeclaration(FieldDeclaration... fieldDeclarations) {
+    return new ClassDeclaration(
+        Modifier.PUBLIC,
+        "MyClass",
+        null,
+        ImmutableList.of(),
+        Arrays.asList(fieldDeclarations));
+  }
+
+}