added Relative reference in location url

Author: Nakul Sabharwal

src/main/java/com/microsoft/graph/httpcore/RedirectHandler.java

@@ -66,9 +66,15 @@ Request getRedirect(
     		final Request request,
     		final Response userResponse) throws ProtocolException {    	
         String location = userResponse.header("Location");
-        if (location == null) return null;
+        if (location == null || location.length() == 0) return null;
 
-        // TODO: If Location header is relative reference then final URL should be relative to original target URL.
+        // For relative URL in location header, the new url to redirect is relative to original request
+        if(location.startsWith("/")) {
+        	if(request.url().toString().endsWith("/")) {
+        		location = location.substring(1);
+        	}
+        	location = request.url() + location;
+        }
 
         HttpUrl requestUrl = userResponse.request().url();
 

src/test/java/com/microsoft/graph/httpcore/RedirectHandlerTest.java

@@ -21,7 +21,7 @@
 public class RedirectHandlerTest {
 
 	String testmeurl = "https://graph.microsoft.com/v1.0/me/";
-	String testurl = "https://graph.microsoft.com/v1.0/";
+	String testurl = "https://graph.microsoft.com/v1.0";
 	String differenthosturl = "https://graph.abc.com/v1.0/";
 
 	@Test
@@ -228,5 +228,39 @@ public void testGetRedirectForPostMethodWithStatusCodeSeeOther() {
 			fail("Redirect handler testGetRedirectForPostMethod1 failure");
 		}
 	}
+	
+	@Test
+	public void testGetRedirectForRelativeURL() throws ProtocolException {
+		RedirectHandler redirectHandler = new RedirectHandler();
+		Request httppost = new Request.Builder().url(testurl).build();
+		
+		Response response = new Response.Builder()
+				.protocol(Protocol.HTTP_1_1)
+				.code(HttpURLConnection.HTTP_SEE_OTHER)
+				.message("See Other")
+				.addHeader("location", "/testrelativeurl")
+				.request(httppost)
+				.build();
+		
+			Request request = redirectHandler.getRedirect(httppost, response);
+			assertTrue(request.url().toString().compareTo(testurl+"/testrelativeurl") == 0);
+	}
+	
+	@Test
+	public void testGetRedirectRelativeLocationRequestURLwithSlash() throws ProtocolException {
+		RedirectHandler redirectHandler = new RedirectHandler();
+		Request httppost = new Request.Builder().url(testmeurl).build();
+		
+		Response response = new Response.Builder()
+				.protocol(Protocol.HTTP_1_1)
+				.code(HttpURLConnection.HTTP_SEE_OTHER)
+				.message("See Other")
+				.addHeader("location", "/testrelativeurl")
+				.request(httppost)
+				.build();
+			Request request = redirectHandler.getRedirect(httppost, response);
+			String expected = "https://graph.microsoft.com/v1.0/me/testrelativeurl";
+			assertTrue(request.url().toString().compareTo(expected) == 0);
+	}
 
 }