fix(router): fix matrix params check to handle 'special' objects

modules/@angular/router/src/create_url_tree.ts

@@ -35,11 +35,16 @@ export function createUrlTree(
 }
 
 function validateCommands(n: NormalizedNavigationCommands): void {
-  if (n.isAbsolute && n.commands.length > 0 && (typeof n.commands[0] === 'object')) {
+  if (n.isAbsolute && n.commands.length > 0 && isMatrixParams(n.commands[0])) {
     throw new Error('Root segment cannot have matrix parameters');
   }
 }
 
+function isMatrixParams(command: any): boolean {
+  return typeof command === 'object' && command.outlets === undefined &&
+      command.segmentPath === undefined;
+}
+
 function tree(
     oldSegmentGroup: UrlSegmentGroup, newSegmentGroup: UrlSegmentGroup, urlTree: UrlTree,
     queryParams: Params, fragment: string): UrlTree {

modules/@angular/router/test/create_url_tree.spec.ts

@@ -54,6 +54,12 @@ describe('createUrlTree', () => {
     expect(serializer.serialize(t)).toEqual('/a/11/d(right:c)');
   });
 
+  it('should support updating secondary segments (absolute)', () => {
+    const p = serializer.parse('/a(right:b)');
+    const t = createRoot(p, ['/', {outlets: {right: ['c']}}]);
+    expect(serializer.serialize(t)).toEqual('/a(right:c)');
+  });
+
   it('should support updating secondary segments', () => {
     const p = serializer.parse('/a(right:b)');
     const t = createRoot(p, [{outlets: {right: ['c', 11, 'd']}}]);