UriComponentsBuilder copies query params through MultiValueMap.addAll

Issue: SPR-17256

spring-core/src/main/java/org/springframework/util/LinkedMultiValueMap.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -117,7 +117,6 @@ public class LinkedMultiValueMap<K, V> implements MultiValueMap<K, V>, Serializa
 	public Map<K, V> toSingleValueMap() {
 		LinkedHashMap<K, V> singleValueMap = new LinkedHashMap<>(this.targetMap.size());
 		this.targetMap.forEach((key, value) -> singleValueMap.put(key, value.get(0)));
-		
 		return singleValueMap;
 	}
 
@@ -191,7 +190,10 @@ public class LinkedMultiValueMap<K, V> implements MultiValueMap<K, V>, Serializa
 	/**
 	 * Create a deep copy of this Map.
 	 * @return a copy of this Map, including a copy of each value-holding List entry
+	 * (consistently using an independent modifiable {@link LinkedList} for each entry)
+	 * along the lines of {@code MultiValueMap.addAll} semantics
 	 * @since 4.2
+	 * @see #addAll(MultiValueMap)
 	 * @see #clone()
 	 */
 	public LinkedMultiValueMap<K, V> deepCopy() {
@@ -203,7 +205,11 @@ public class LinkedMultiValueMap<K, V> implements MultiValueMap<K, V>, Serializa
 	/**
 	 * Create a regular copy of this Map.
 	 * @return a shallow copy of this Map, reusing this Map's value-holding List entries
+	 * (even if some entries are shared or unmodifiable) along the lines of standard
+	 * {@code Map.put} semantics
 	 * @since 4.2
+	 * @see #put(Object, List)
+	 * @see #putAll(Map)
 	 * @see LinkedMultiValueMap#LinkedMultiValueMap(Map)
 	 * @see #deepCopy()
 	 */

spring-web/src/main/java/org/springframework/web/util/UriComponentsBuilder.java

@@ -705,7 +705,7 @@ public class UriComponentsBuilder implements UriBuilder, Cloneable {
 	@Override
 	public UriComponentsBuilder queryParams(@Nullable MultiValueMap<String, String> params) {
 		if (params != null) {
-			this.queryParams.putAll(params);
+			this.queryParams.addAll(params);
 		}
 		return this;
 	}

spring-web/src/test/java/org/springframework/web/util/UriComponentsBuilderTests.java

@@ -36,13 +36,15 @@ import static org.hamcrest.Matchers.*;
 import static org.junit.Assert.*;
 
 /**
- * Unit tests for {@link org.springframework.web.util.UriComponentsBuilder}.
+ * Unit tests for {@link UriComponentsBuilder}.
  *
  * @author Arjen Poutsma
+ * @author Rossen Stoyanchev
  * @author Phillip Webb
  * @author Oliver Gierke
- * @author David Eckel
+ * @author Juergen Hoeller
  * @author Sam Brannen
+ * @author David Eckel
  */
 public class UriComponentsBuilderTests {
 
@@ -902,9 +904,19 @@ public class UriComponentsBuilderTests {
 	public void uriComponentsNotEqualAfterNormalization() {
 		UriComponents uri1 = UriComponentsBuilder.fromUriString("http://test.com").build().normalize();
 		UriComponents uri2 = UriComponentsBuilder.fromUriString("http://test.com/").build();
+
 		assertTrue(uri1.getPathSegments().isEmpty());
 		assertTrue(uri2.getPathSegments().isEmpty());
 		assertNotEquals(uri1, uri2);
 	}
 
+	@Test  // SPR-17256
+	public void uriComponentsWithMergedQueryParams() {
+		String uri = UriComponentsBuilder.fromUriString("http://localhost:8081")
+				.uriComponents(UriComponentsBuilder.fromUriString("/{path}?sort={sort}").build())
+				.queryParam("sort", "another_value").build().toString();
+
+		assertEquals("http://localhost:8081/{path}?sort={sort}&sort=another_value", uri);
+	}
+
 }