Explicitly exclude form-body params that appear in query string

Fixes gh-1080

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/zuul/filters/pre/FormBodyWrapperFilter.java

@@ -20,12 +20,15 @@ import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.lang.reflect.Field;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map.Entry;
+import java.util.Set;
 
 import javax.servlet.ServletInputStream;
 import javax.servlet.http.HttpServletRequest;
 
+import org.apache.commons.lang3.StringUtils;
 import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpOutputMessage;
@@ -165,10 +168,13 @@ public class FormBodyWrapperFilter extends ZuulFilter {
 		private synchronized void buildContentData() {
 			try {
 				MultiValueMap<String, Object> builder = new LinkedMultiValueMap<String, Object>();
+				Set<String> queryParams = findQueryParams();
 				for (Entry<String, String[]> entry : this.request.getParameterMap()
 						.entrySet()) {
-					for (String value : entry.getValue()) {
-						builder.add(entry.getKey(), value);
+					if (!queryParams.contains(entry.getKey())) {
+						for (String value : entry.getValue()) {
+							builder.add(entry.getKey(), value);
+						}
 					}
 				}
 				if (this.request instanceof MultipartRequest) {
@@ -202,6 +208,20 @@ public class FormBodyWrapperFilter extends ZuulFilter {
 			}
 		}
 
+		private Set<String> findQueryParams() {
+			Set<String> result = new HashSet<>();
+			String query = this.request.getQueryString();
+			if (query != null) {
+				for (String value : StringUtils.split(query, "&")) {
+					if (value.contains("=")) {
+						value = value.substring(0, value.indexOf("="));
+					}
+					result.add(value);
+				}
+			}
+			return result;
+		}
+
 		private class FormHttpOutputMessage implements HttpOutputMessage {
 
 			private HttpHeaders headers = new HttpHeaders();

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/zuul/FormZuulProxyApplicationTests.java

@@ -137,6 +137,32 @@ public class FormZuulProxyApplicationTests {
 		assertEquals(HttpStatus.OK, result.getStatusCode());
 		assertEquals("Posted! {foo=[bar]}", result.getBody());
 	}
+
+	@Test
+	public void postWithUrlParams() throws Exception {
+		MultiValueMap<String, String> form = new LinkedMultiValueMap<String, String>();
+		form.set("foo", "bar");
+		HttpHeaders headers = new HttpHeaders();
+		headers.setContentType(MediaType.valueOf(
+				MediaType.APPLICATION_FORM_URLENCODED_VALUE + "; charset=UTF-8"));
+		ResponseEntity<String> result = new TestRestTemplate().exchange(
+				"http://localhost:" + this.port + "/simple/form?uriParam=uriValue",
+				HttpMethod.POST,
+				new HttpEntity<MultiValueMap<String, String>>(form, headers),
+				String.class);
+		assertEquals(HttpStatus.OK, result.getStatusCode());
+		assertEquals("Posted! {uriParam=[uriValue], foo=[bar]}", result.getBody());
+	}
+
+	@Test
+	public void getWithUrlParams() throws Exception {
+		ResponseEntity<String> result = new TestRestTemplate().exchange(
+				"http://localhost:" + this.port + "/simple/form?uriParam=uriValue",
+				HttpMethod.GET, null, String.class);
+		assertEquals(HttpStatus.OK, result.getStatusCode());
+		assertEquals("Posted! {uriParam=[uriValue]}", result.getBody());
+	}
+
 }
 
 // Don't use @SpringBootApplication because we don't want to component scan
@@ -156,6 +182,12 @@ class FormZuulProxyApplication {
 		return "Posted! " + form;
 	}
 
+	@RequestMapping(value = "/form", method = RequestMethod.GET)
+	public String get(@RequestParam MultiValueMap<String, String> form)
+			throws IOException {
+		return "Posted! " + form;
+	}
+
 	// TODO: Why does this not work if you add @RequestParam as above?
 	@RequestMapping(value = "/file", method = RequestMethod.POST)
 	public String file(@RequestParam(required = false) MultipartFile file)