Fix #1420, deep cleans routes as opposed to just the first level.

route/route.js

@@ -646,22 +646,29 @@ steal('can/util', 'can/map', 'can/list','can/util/string/deparam', function (can
 		var hash = can.route._call("matchingPartOfURL");
 		var oldParams = curParams;
 		curParams = can.route.deparam(hash);
-
 		// if the hash data is currently changing, or
 		// the hash is what we set it to anyway, do NOT change the hash
 		if (!changingData || hash !== lastHash) {
 			can.batch.start();
-			for(var attr in oldParams){
-				if(!curParams[attr]){
-					can.route.removeAttr(attr);
-				}
-			}
+			recursiveClean(oldParams, curParams, can.route.data);
+
 			can.route.attr(curParams);
 			// trigger a url change so its possible to live-bind on url-based changes
 			can.batch.trigger(eventsObject,"__url",[hash, lastHash]);
 			can.batch.stop();
 		}
 	};
 
+	var recursiveClean = function(old, cur, data){
+		for(var attr in old){
+			if(!cur[attr]){
+				data.removeAttr(attr);
+			}
+			else if(Object.prototype.toString.call(old[attr]) === "[object Object]") {
+				recursiveClean( old[attr], cur[attr], data.attr(attr) );
+			}
+		}
+	};
+
 	return can.route;
 });

route/route_test.js

@@ -692,6 +692,40 @@ steal("can/route", "can/test", function () {
 				},1);
 			});
 		});
+
+		test("routes should deep clean", function() {
+			expect(2);
+			setupRouteTest(function (iframe, iCanRoute, loc) {
+				iCanRoute.ready();
+				var hash1 = can.route.url({
+					panelA: {
+						name: "fruit",
+						id: 15,
+						show: true
+					}
+				});
+				var hash2 = can.route.url({
+					panelA: {
+						name: "fruit",
+						id: 20,
+						read: false
+					}
+				});
+
+
+				loc.hash = hash1;
+
+				loc.hash = hash2;
+
+				setTimeout(function() {
+					equal(iCanRoute.attr("panelA.id"), 20, "id should change");
+					equal(iCanRoute.attr("panelA.show"), undefined, "show should be removed");
+
+					teardownRouteTest();
+				}, 30);
+
+			});
+		});
 	}
 
 	test("escaping periods", function () {