fix(router): process empty path segment when preceding a named outlet (#26243)

PR Close #10726

PR Close #26243

packages/router/src/recognize.ts

@@ -70,6 +70,14 @@ class Recognizer {
   processSegmentGroup(config: Route[], segmentGroup: UrlSegmentGroup, outlet: string):
       TreeNode<ActivatedRouteSnapshot>[] {
     if (segmentGroup.segments.length === 0 && segmentGroup.hasChildren()) {
+      const empties = config.filter(r => emptyPathMatch(segmentGroup, segmentGroup.segments, r));
+      if (empties.length !== 0) {
+        try {
+          return this.processSegment(empties, segmentGroup, segmentGroup.segments, outlet);
+        } catch (e) {
+          if (!(e instanceof NoMatch)) throw e;
+        }
+      }
       return this.processChildren(config, segmentGroup);
     }
 

packages/router/test/recognize.spec.ts

@@ -263,6 +263,20 @@ describe('recognize', () => {
         });
       });
 
+      it('should work with children outlets', () => {
+        checkRecognize(
+            [{
+              path: '',
+              component: ComponentA,
+              children: [{path: 'b', outlet: 'b', component: ComponentB}]
+            }],
+            '(b:b)', (s: RouterStateSnapshot) => {
+              checkActivatedRoute((s as any).firstChild(s.root) !, '', {}, ComponentA);
+              checkActivatedRoute(
+                  (s as any).firstChild((s as any).firstChild(s.root)) !, 'b', {}, ComponentB, 'b');
+            });
+      });
+
       it('should match when terminal', () => {
         checkRecognize(
             [{path: '', pathMatch: 'full', component: ComponentA}], '',