fix(router): reset URL to the stable state when a navigation gets canceled

Closes #10321

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

@@ -702,7 +702,7 @@ export class Router {
             this.currentRouterState = state;
 
             if (!shouldPreventPushState) {
-              let path = this.urlSerializer.serialize(this.rawUrlTree);
+              const path = this.urlSerializer.serialize(this.rawUrlTree);
               if (this.location.isCurrentPathEqualTo(path) || shouldReplaceUrl) {
                 this.location.replaceState(path);
               } else {
@@ -722,12 +722,14 @@ export class Router {
                       new NavigationEnd(id, this.serializeUrl(url), this.serializeUrl(appliedUrl)));
                   resolvePromise(true);
                 } else {
+                  this.resetUrlToCurrentUrlTree();
                   this.routerEvents.next(new NavigationCancel(id, this.serializeUrl(url), ''));
                   resolvePromise(false);
                 }
               },
               (e: any) => {
                 if (e instanceof NavigationCancelingError) {
+                  this.resetUrlToCurrentUrlTree();
                   this.navigated = true;
                   this.routerEvents.next(
                       new NavigationCancel(id, this.serializeUrl(url), e.message));
@@ -741,14 +743,17 @@ export class Router {
                   }
                 }
 
-                if (id === this.navigationId) {
                 this.currentRouterState = storedState;
                 this.currentUrlTree = storedUrl;
                 this.rawUrlTree = this.urlHandlingStrategy.merge(this.currentUrlTree, rawUrl);
                 this.location.replaceState(this.serializeUrl(this.rawUrlTree));
+              });
+    });
   }
-              });
+
-    });
+  private resetUrlToCurrentUrlTree(): void {
+    const path = this.urlSerializer.serialize(this.rawUrlTree);
+    this.location.replaceState(path);
   }
 }
 

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

@@ -1213,6 +1213,35 @@ describe('Integration', () => {
              expect(location.path()).toEqual('/team/22');
            })));
       });
+
+      describe('should reset the location when cancleling a navigation', () => {
+        beforeEach(() => {
+          TestBed.configureTestingModule({
+            providers: [{
+              provide: 'alwaysFalse',
+              useValue: (a: ActivatedRouteSnapshot, b: RouterStateSnapshot) => { return false; }
+            }]
+          });
+        });
+
+        it('works', fakeAsync(inject([Router, Location], (router: Router, location: Location) => {
+             const fixture = createRoot(router, RootCmp);
+
+             router.resetConfig([
+               {path: 'one', component: SimpleCmp},
+               {path: 'two', component: SimpleCmp, canActivate: ['alwaysFalse']}
+             ]);
+
+             router.navigateByUrl('/one');
+             advance(fixture);
+             expect(location.path()).toEqual('/one');
+
+             location.go('/two');
+             advance(fixture);
+             expect(location.path()).toEqual('/one');
+
+           })));
+      });
     });
 
     describe('CanDeactivate', () => {

tools/public_api_guard/router/index.d.ts

@@ -228,7 +228,7 @@ export declare class RouterLink {
     routerLink: any[] | string;
     urlTree: UrlTree;
     constructor(router: Router, route: ActivatedRoute, locationStrategy: LocationStrategy);
-    onClick(button: number, ctrlKey: boolean, metaKey: boolean): boolean;
+    onClick(): boolean;
 }
 
 /** @stable */