Escape & characaters in curl request URLs

Without escaping, the & will cause bash to truncate the URL and
background the curl process.

Closes gh-35

spring-restdocs/src/main/java/org/springframework/restdocs/curl/CurlDocumentation.java

@@ -186,7 +186,7 @@ public abstract class CurlDocumentation {
 
 		private String getQueryString(HttpServletRequest request) {
 			if (request.getQueryString() != null) {
-				return request.getQueryString();
+				return request.getQueryString().replace("&", "\\&");
 			}
 			if (isGetRequest(request)) {
 				return toQueryString(request.getParameterMap());
@@ -199,7 +199,7 @@ public abstract class CurlDocumentation {
 			for (Map.Entry<String, String[]> entry : map.entrySet()) {
 				for (String value : entry.getValue()) {
 					if (sb.length() > 0) {
-						sb.append("&");
+						sb.append("\\&");
 					}
 					sb.append(urlEncodeUTF8(entry.getKey())).append('=')
 							.append(urlEncodeUTF8(value));

spring-restdocs/src/test/java/org/springframework/restdocs/curl/CurlDocumentationTests.java

@@ -134,7 +134,7 @@ public class CurlDocumentationTests {
 		documentCurlRequest("request-with-multiple-parameters").handle(
 				new StubMvcResult(request, null));
 		assertThat(requestSnippetLines("request-with-multiple-parameters"),
-				hasItem("$ curl http://localhost/foo?k1=v1&k1=v1-bis&k2=v2 -i"));
+				hasItem("$ curl http://localhost/foo?k1=v1\\&k1=v1-bis\\&k2=v2 -i"));
 	}
 
 	@Test