Fix MockMvc + HttpPutFormContentFilter issue

Issue: SPR-15753

spring-test/src/test/java/org/springframework/test/web/servlet/samples/spr/FormContentTests.java

@@ -0,0 +1,83 @@
+/*
+ * 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://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.test.web.servlet.samples.spr;
+
+import org.junit.Test;
+
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.filter.HttpPutFormContentFilter;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
+
+/**
+ * Test for issues related to form content.
+ * @author Rossen Stoyanchev
+ */
+public class FormContentTests {
+
+	@Test // SPR-15753
+	public void formContentIsNotDuplicated() throws Exception {
+
+		MockMvc mockMvc = MockMvcBuilders.standaloneSetup(new Spr15753Controller())
+				.addFilter(new HttpPutFormContentFilter())
+				.build();
+
+		mockMvc.perform(put("/").content("d1=a&d2=s").contentType(MediaType.APPLICATION_FORM_URLENCODED))
+				.andExpect(content().string("d1:a, d2:s."));
+
+	}
+
+
+	@RestController
+	public class Spr15753Controller {
+
+		@PutMapping
+		public String test(Data d) {
+			return String.format("d1:%s, d2:%s.", d.getD1(), d.getD2());
+		}
+	}
+
+	public class Data {
+
+		private String d1;
+
+		private String d2;
+
+		public Data() {
+		}
+
+		public String getD1() {
+			return d1;
+		}
+
+		public void setD1(String d1) {
+			this.d1 = d1;
+		}
+
+		public String getD2() {
+			return d2;
+		}
+
+		public void setD2(String d2) {
+			this.d2 = d2;
+		}
+	}
+}