From 6518f8f7fd2a3be8dbb47560ca91c8b266b6b0fa Mon Sep 17 00:00:00 2001
From: Wanderlei Souza <wandi.darko@gmail.com>
Date: Sun, 22 Nov 2020 18:49:44 -0300
Subject: [PATCH] Allow to exclude an empty set of ErrorAttributes

See gh-24230
---
 .../boot/web/error/ErrorAttributeOptions.java |  4 +-
 .../error/ErrorAttributesOptionsTests.java    | 51 +++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/error/ErrorAttributesOptionsTests.java

diff --git a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/error/ErrorAttributeOptions.java b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/error/ErrorAttributeOptions.java
index b930aa346f..53e1e75b39 100644
--- a/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/error/ErrorAttributeOptions.java
+++ b/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/error/ErrorAttributeOptions.java
@@ -27,6 +27,7 @@ import java.util.Set;
  *
  * @author Scott Frederick
  * @author Phillip Webb
+ * @author Wanderlei Souza
  * @since 2.3.0
  */
 public final class ErrorAttributeOptions {
@@ -76,7 +77,8 @@ public final class ErrorAttributeOptions {
 	 * @return an {@code ErrorAttributeOptions}
 	 */
 	public ErrorAttributeOptions excluding(Include... excludes) {
-		EnumSet<Include> updated = EnumSet.copyOf(this.includes);
+		EnumSet<Include> updated = (this.includes.isEmpty()) ? EnumSet.noneOf(Include.class)
+				: EnumSet.copyOf(this.includes);
 		updated.removeAll(Arrays.asList(excludes));
 		return new ErrorAttributeOptions(Collections.unmodifiableSet(updated));
 	}
diff --git a/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/error/ErrorAttributesOptionsTests.java b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/error/ErrorAttributesOptionsTests.java
new file mode 100644
index 0000000000..0a77793329
--- /dev/null
+++ b/spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/servlet/error/ErrorAttributesOptionsTests.java
@@ -0,0 +1,51 @@
+/*
+ * Copyright 2012-2020 the original author or authors.
+ *
+ * Licensed 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
+ *
+ *      https://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.springframework.boot.web.servlet.error;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.EnumSet;
+import java.util.Set;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.web.error.ErrorAttributeOptions;
+import org.springframework.boot.web.error.ErrorAttributeOptions.Include;
+
+/**
+ * Tests for {@link ErrorAttributesOptions}.
+ *
+ * @author Wanderlei Souza
+ */
+class ErrorAttributesOptionsTests {
+
+	@Test
+	void excludingFromEmptySetWithoutErrors() {
+		Set<Include> includes = EnumSet.noneOf(Include.class);
+		ErrorAttributeOptions errorAttributeOptions = ErrorAttributeOptions.of(includes);
+		errorAttributeOptions = errorAttributeOptions.excluding(Include.EXCEPTION);
+		assertThat(errorAttributeOptions.getIncludes().isEmpty());
+	}
+	
+	@Test
+	void includingInEmptySetWithoutErrors() {
+		Set<Include> includes = EnumSet.noneOf(Include.class);
+		ErrorAttributeOptions errorAttributeOptions = ErrorAttributeOptions.of(includes);
+		errorAttributeOptions = errorAttributeOptions.including(Include.EXCEPTION);
+		assertThat(errorAttributeOptions.getIncludes().isEmpty());
+	}
+
+}