fix: merge fix from N Core

NativeScript/NativeScript@b3f9c0d

Author: farfromrefug

src/tabs/tabs.ios.ts

@@ -1106,16 +1106,31 @@ export class Tabs extends TabsBase {
             // do not make layout changes while the animation is in progress https://stackoverflow.com/a/47031524/613113
             this.visitFrames(item, (frame) => (frame._animationInProgress = true));
 
+            const doneAnimating = () => {
+                this.visitFrames(item, (frame) => (frame._animationInProgress = false));
+
+                this._canSelectItem = true;
+                this._setCanBeLoaded(value);
+                this._loadUnloadTabItems(value);
+            };
+
             invokeOnRunLoop(() =>
                 this.viewController.setViewControllersDirectionAnimatedCompletion(controllers, navigationDirection, this.animationEnabled, (finished: boolean) => {
-                    this.visitFrames(item, (frame) => (frame._animationInProgress = false));
                     if (finished) {
-                        // HACK: UIPageViewController fix; see https://stackoverflow.com/a/17330606
-                        invokeOnRunLoop(() => this.viewController.setViewControllersDirectionAnimatedCompletion(controllers, navigationDirection, false, null));
-
-                        this._canSelectItem = true;
-                        this._setCanBeLoaded(value);
-                        this._loadUnloadTabItems(value);
+                        if (this.animationEnabled) {
+                            // HACK: UIPageViewController fix; see https://stackoverflow.com/a/17330606
+                            // Prior Hack fails on iOS 10.3 during tests with v8 engine...
+                            // Leaving the above link in case we need to special case this for only iOS > 10.3?
+
+                            // HACK: UIPageViewController fix; see https://stackoverflow.com/questions/15325891
+                            invokeOnRunLoop(() => {
+                                this.viewController.dataSource = null;
+                                (this.viewController as any).dataSource = this.viewController;
+                                doneAnimating();
+                            });
+                        } else {
+                            doneAnimating();
+                        }
                     }
                 })
             );