Stop navigating at end of timeline

src/site/html/static/js/post_overlay.js

@@ -175,11 +175,15 @@ function loadPostOverlay(shortcode, stateChangeType) {
 							canInteractWithNavigation = false
 							var futureShortcode = entry.getPreviousShortcode()
 						}
+						if (futureShortcode) {
 							await loadPostOverlay(futureShortcode, "replace")
 							const newOverlay = postOverlays.slice(-1)[0]
 							if (newOverlay === overlay) { // was cancelled
 								canInteractWithNavigation = true
 							}
+						} else {
+							canInteractWithNavigation = true
+						}
 					}
 				}
 			}