DATAREST-674 - Defensively handle potential double slashes in lookup

path.

We now defensively replace all double slashes contained in the lookup
path as Spring 4.2 might return such paths due to a regression in
UrlPathHelper. This might occur if the original URL contains
intermediate matrix parameters (e.g. /books/;test/1) whose removal now
results in double slashes and thus the downstream repository metadata
lookup to fail.

Related tickets: SPR-13455.

spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/BaseUri.java

@@ -111,6 +111,9 @@ public class BaseUri {
 
 		Assert.notNull(lookupPath, "Lookup path must not be null!");
 
+		// Temporary fix for SPR-13455
+		lookupPath = lookupPath.replaceAll("//", "/");
+		
 		lookupPath = trimTrailingCharacter(lookupPath, '/');
 
 		if (!baseUri.isAbsolute()) {

spring-data-rest-webmvc/src/test/java/org/springframework/data/rest/webmvc/BaseUriUnitTests.java

@@ -87,4 +87,13 @@ public class BaseUriUnitTests {
 		assertThat(uri.getRepositoryLookupPath("/foo/people"), is("/people"));
 		assertThat(uri.getRepositoryLookupPath("/foo/people/"), is("/people"));
 	}
+
+	/**
+	 * @see DATAREST-674
+	 * @see SPR-13455
+	 */
+	@Test
+	public void repositoryLookupPathHandlesDoubleSlashes() {
+		assertThat(BaseUri.NONE.getRepositoryLookupPath("/books//1"), is("/books/1"));
+	}
 }