Prevent short swipes if starting a gesture on an internally scrolling…

… element, mitigating accidental navigation while still allowing for intentional navigation gestures. (#3919)

mobile/cmp/navigator/NavigatorModel.ts

@@ -149,6 +149,7 @@ export class NavigatorModel extends HoistModel {
         // to propagate to scrollable elements within the page.
         swiper.on('touchStart', (s, event: PointerEvent) => {
             swiper.allowTouchMove = false;
+            swiper.params.shortSwipes = true;
             this._touchStartX = event.pageX;
         });
 
@@ -175,6 +176,12 @@ export class NavigatorModel extends HoistModel {
                     swiper.allowTouchMove =
                         swiper.progress < 1 || !isDraggableEl(scrollableParent, 'right');
 
+                    // Disable short swipes to prevent accidental navigation when reaching the
+                    // end of the scrollable parent.
+                    if (!swiper.allowTouchMove) {
+                        swiper.params.shortSwipes = false;
+                    }
+
                     // During the swiper transition, undo the scrollable parent's internal scroll
                     // to keep it static.
                     if (swiper.progress < 1) {