Leave query un-encoded in MockMvc request builder

Issue: SPR-12880

spring-test/src/main/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilder.java

@@ -581,8 +581,7 @@ public class MockHttpServletRequestBuilder
 
 		try {
 			if (this.uriComponents.getQuery() != null) {
-				String query = UriUtils.decode(this.uriComponents.getQuery(), "UTF-8");
-				request.setQueryString(query);
+				request.setQueryString(this.uriComponents.getQuery());
 			}
 
 			for (Entry<String, List<String>> entry : this.uriComponents.getQueryParams().entrySet()) {

spring-test/src/test/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilderTests.java

@@ -210,7 +210,7 @@ public class MockHttpServletRequestBuilderTests {
 
 		MockHttpServletRequest request = this.builder.buildRequest(this.servletContext);
 
-		assertEquals("foo[0]=bar&foo[1]=baz", request.getQueryString());
+		assertEquals("foo%5B0%5D=bar&foo%5B1%5D=baz", request.getQueryString());
 		assertEquals("bar", request.getParameter("foo[0]"));
 		assertEquals("baz", request.getParameter("foo[1]"));
 	}
@@ -221,7 +221,7 @@ public class MockHttpServletRequestBuilderTests {
 
 		MockHttpServletRequest request = this.builder.buildRequest(this.servletContext);
 
-		assertEquals("foo=bar=baz", request.getQueryString());
+		assertEquals("foo=bar%3Dbaz", request.getQueryString());
 		assertEquals("bar=baz", request.getParameter("foo"));
 	}