UriComponents allows "+" in a query param

Issue: SPR-14828

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

@@ -554,7 +554,7 @@ final class HierarchicalUriComponents extends UriComponents {
 		QUERY_PARAM {
 			@Override
 			public boolean isAllowed(int c) {
-				if ('=' == c || '+' == c || '&' == c) {
+				if ('=' == c || '&' == c) {
 					return false;
 				}
 				else {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -189,6 +189,14 @@ public class UriComponentsBuilderTests {
 		assertEquals("1USD=?EUR", result.getQueryParams().getFirst("q"));
 	}
 
+	@Test // SPR-14828
+	public void fromUriStringQueryParamEncodedAndContainingPlus() throws Exception {
+		String httpUrl = "http://localhost:8080/test/print?value=%EA%B0%80+%EB%82%98";
+		URI uri = UriComponentsBuilder.fromHttpUrl(httpUrl).build(true).toUri();
+
+		assertEquals(httpUrl, uri.toString());
+	}
+
 	@Test // SPR-10779
 	public void fromHttpUrlStringCaseInsesitiveScheme() {
 		assertEquals("http", UriComponentsBuilder.fromHttpUrl("HTTP://www.google.com").build().getScheme());