fix(ivy): support inserting a `viewRef` that is already present (#34052)

When inserting a `viewRef` it is possible to not provide
an `index`, which is regarded as appending to the end of
the container.

If the `viewRef` already exists in the container, then
this results in a move. But there was a fault in the logic
that computed where to insert the `viewRef` that did not
account for the fact that the `viewRef` was already in
the container, so the insertion `index` was outside the
bounds of the array.

Fixes #33924

PR Close #34052

packages/core/src/render3/view_engine_compatibility.ts

@@ -245,14 +245,16 @@ export function createContainerRef(
         }
         this.allocateContainerIfNeeded();
         const lView = (viewRef as ViewRef<any>)._lView !;
-        const adjustedIdx = this._adjustIndex(index);
 
         if (viewAttachedToContainer(lView)) {
           // If view is already attached, fall back to move() so we clean up
           // references appropriately.
-          return this.move(viewRef, adjustedIdx);
+          // Note that we "shift" -1 because the move will involve inserting
+          // one view but also removing one view.
+          return this.move(viewRef, this._adjustIndex(index, -1));
         }
 
+        const adjustedIdx = this._adjustIndex(index);
         insertView(lView, this._lContainer, adjustedIdx);
 
         const beforeNode = getBeforeNodeForView(adjustedIdx, this._lContainer);

packages/core/test/acceptance/view_container_ref_spec.ts

@@ -204,6 +204,22 @@ describe('ViewContainerRef', () => {
         expect(fixture.nativeElement.textContent).toEqual('102');
       }
     });
+
+    it('should do nothing when a view is re-inserted / moved at the same index', () => {
+      const fixture = TestBed.createComponent(ViewContainerRefApp);
+      fixture.detectChanges();
+
+      const templates = fixture.componentInstance.vcrComp.templates.toArray();
+      const viewContainerRef = fixture.componentInstance.vcrComp.vcr;
+
+      const ref0 = viewContainerRef.createEmbeddedView(templates[0]);
+
+      expect(fixture.nativeElement.textContent).toEqual('0');
+
+      // insert again at the same place but without specifying any index
+      viewContainerRef.insert(ref0);
+      expect(fixture.nativeElement.textContent).toEqual('0');
+    });
   });
 
   describe('move', () => {