Polish contribution

See gh-31320

spring-webflux/src/main/java/org/springframework/web/reactive/result/condition/ParamsRequestCondition.java

@@ -86,10 +86,7 @@ public final class ParamsRequestCondition extends AbstractRequestCondition<Param
 	 */
 	@Override
 	public ParamsRequestCondition combine(ParamsRequestCondition other) {
-		if (isEmpty() && other.isEmpty()) {
-			return this;
-		}
-		else if (other.isEmpty()) {
+		if (other.isEmpty()) {
 			return this;
 		}
 		else if (isEmpty()) {

spring-webflux/src/test/java/org/springframework/web/reactive/result/condition/ParamsRequestConditionTests.java

@@ -28,7 +28,9 @@ import static org.springframework.web.testfixture.http.server.reactive.MockServe
 
 /**
  * Unit tests for {@link ParamsRequestCondition}.
+ *
  * @author Rossen Stoyanchev
+ * @author Stephane Nicoll
  */
 public class ParamsRequestConditionTests {
 
@@ -42,43 +44,43 @@ public class ParamsRequestConditionTests {
 	}
 
 	@Test
-	public void paramPresent() throws Exception {
+	public void paramPresent() {
 		ParamsRequestCondition condition = new ParamsRequestCondition("foo");
 		assertThat(condition.getMatchingCondition(MockServerWebExchange.from(get("/path?foo=")))).isNotNull();
 	}
 
 	@Test // SPR-15831
-	public void paramPresentNullValue() throws Exception {
+	public void paramPresentNullValue() {
 		ParamsRequestCondition condition = new ParamsRequestCondition("foo");
 		assertThat(condition.getMatchingCondition(MockServerWebExchange.from(get("/path?foo")))).isNotNull();
 	}
 
 	@Test
-	public void paramPresentNoMatch() throws Exception {
+	public void paramPresentNoMatch() {
 		ParamsRequestCondition condition = new ParamsRequestCondition("foo");
 		assertThat(condition.getMatchingCondition(MockServerWebExchange.from(get("/path?bar=")))).isNull();
 	}
 
 	@Test
-	public void paramNotPresent() throws Exception {
+	public void paramNotPresent() {
 		MockServerWebExchange exchange = MockServerWebExchange.from(get("/"));
 		assertThat(new ParamsRequestCondition("!foo").getMatchingCondition(exchange)).isNotNull();
 	}
 
 	@Test
-	public void paramValueMatch() throws Exception {
+	public void paramValueMatch() {
 		ParamsRequestCondition condition = new ParamsRequestCondition("foo=bar");
 		assertThat(condition.getMatchingCondition(MockServerWebExchange.from(get("/path?foo=bar")))).isNotNull();
 	}
 
 	@Test
-	public void paramValueNoMatch() throws Exception {
+	public void paramValueNoMatch() {
 		ParamsRequestCondition condition = new ParamsRequestCondition("foo=bar");
 		assertThat(condition.getMatchingCondition(MockServerWebExchange.from(get("/path?foo=bazz")))).isNull();
 	}
 
 	@Test
-	public void compareTo() throws Exception {
+	public void compareTo() {
 		ServerWebExchange exchange = MockServerWebExchange.from(get("/"));
 
 		ParamsRequestCondition condition1 = new ParamsRequestCondition("foo", "bar", "baz");
@@ -112,6 +114,24 @@ public class ParamsRequestConditionTests {
 		assertThat(condition1.compareTo(condition2, exchange)).as("Negated match should not count as more specific").isEqualTo(0);
 	}
 
+	@Test
+	public void combineWitOtherEmpty() {
+		ParamsRequestCondition condition1 = new ParamsRequestCondition("foo=bar");
+		ParamsRequestCondition condition2 = new ParamsRequestCondition();
+
+		ParamsRequestCondition result = condition1.combine(condition2);
+		assertThat(result).isEqualTo(condition1);
+	}
+
+	@Test
+	public void combineWitThisEmpty() {
+		ParamsRequestCondition condition1 = new ParamsRequestCondition();
+		ParamsRequestCondition condition2 = new ParamsRequestCondition("foo=bar");
+
+		ParamsRequestCondition result = condition1.combine(condition2);
+		assertThat(result).isEqualTo(condition2);
+	}
+
 	@Test
 	public void combine() {
 		ParamsRequestCondition condition1 = new ParamsRequestCondition("foo=bar");

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/condition/ParamsRequestCondition.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -93,7 +93,7 @@ public final class ParamsRequestCondition extends AbstractRequestCondition<Param
 		if (other.isEmpty()) {
 			return this;
 		}
-		if (isEmpty()) {
+		else if (isEmpty()) {
 			return other;
 		}
 		Set<ParamExpression> set = new LinkedHashSet<>(this.expressions);

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/condition/ParamsRequestConditionTests.java

@@ -27,7 +27,9 @@ import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * Unit tests for {@link ParamsRequestCondition}.
+ *
  * @author Arjen Poutsma
+ * @author Stephane Nicoll
  */
 public class ParamsRequestConditionTests {
 
@@ -123,6 +125,24 @@ public class ParamsRequestConditionTests {
 		assertThat(condition1.compareTo(condition2, request)).as("Negated match should not count as more specific").isEqualTo(0);
 	}
 
+	@Test
+	public void combineWithOtherEmpty() {
+		ParamsRequestCondition condition1 = new ParamsRequestCondition("foo=bar");
+		ParamsRequestCondition condition2 = new ParamsRequestCondition();
+
+		ParamsRequestCondition result = condition1.combine(condition2);
+		assertThat(result).isEqualTo(condition1);
+	}
+
+	@Test
+	public void combineWithThisEmpty() {
+		ParamsRequestCondition condition1 = new ParamsRequestCondition();
+		ParamsRequestCondition condition2 = new ParamsRequestCondition("foo=bar");
+
+		ParamsRequestCondition result = condition1.combine(condition2);
+		assertThat(result).isEqualTo(condition2);
+	}
+
 	@Test
 	public void combine() {
 		ParamsRequestCondition condition1 = new ParamsRequestCondition("foo=bar");