Fix activity recreation crashes with tabs and complex view hierarchies

edusperoni · edusperoni · commit a6ca6bee6ed2 · 2026-05-19T23:32:18.000-03:00
When "Don't keep activities" is enabled (or the system destroys the activity
to reclaim memory), NativeScript apps using ViewPager2-based tabs (e.g.
@nativescript-community/ui-material-tabs) crash on foregrounding.

Two root causes are addressed:

1. ActionBar's disposeNativeView() nulled _actionItems, causing
   "Cannot read properties of null (reading 'addItem')" when the action bar
   was recreated during _setupUI after activity destruction.

2. Android's FragmentManager restores all fragments from savedInstanceState
   during super.onCreate(), including third-party fragments (ViewPager2's
   f0, f1, etc.). NativeScript's _tearDownUI/_setupUI cycle rebuilds the
   entire view tree from scratch, leaving these restored fragments orphaned
   — they reference container views that no longer exist, causing "Fragment
   does not have a view" errors. We now remove non-NativeScript fragments
   immediately after super.onCreate() while preserving core's own fragments
   (tagged fragment{id}[{depth}]) which have a proper restoration path via
   _processNextNavigationEntry and FragmentCallbacksImplementation.onCreateView.
diff --git a/packages/core/ui/action-bar/action-bar-common.ts b/packages/core/ui/action-bar/action-bar-common.ts
@@ -29,7 +29,6 @@ export class ActionBarBase extends View implements ActionBarDefinition {
 	public effectiveContentInsetRight: number;
 
 	disposeNativeView() {
-		this._actionItems = null;
 		super.disposeNativeView();
 	}
 
diff --git a/packages/core/ui/frame/index.android.ts b/packages/core/ui/frame/index.android.ts
@@ -861,6 +861,33 @@ export class ActivityCallbacksImplementation implements AndroidActivityCallbacks
 		const isRestart = !!savedInstanceState && moduleLoaded;
 		superFunc.call(activity, isRestart ? savedInstanceState : null);
 
+		if (isRestart && activity.getSupportFragmentManager) {
+			// Remove restored fragments that NativeScript will recreate via _setupUI/createNativeView.
+			// NativeScript tears down and rebuilds the entire view tree on activity recreation,
+			// so restored fragments (especially from ViewPager2/tabs) become orphaned without views.
+			// NativeScript core's own fragments use tags like "fragment{id}[{depth}]" and are
+			// handled by _processNextNavigationEntry. We remove all non-NativeScript fragments.
+			const fm = activity.getSupportFragmentManager();
+			const fragments = fm.getFragments();
+			if (fragments && fragments.size() > 0) {
+				const ft = fm.beginTransaction();
+				let removed = false;
+				for (let i = fragments.size() - 1; i >= 0; i--) {
+					const f = fragments.get(i);
+					if (!f) continue;
+					const tag = f.getTag();
+					if (tag && tag.startsWith('fragment')) {
+						continue;
+					}
+					ft.remove(f);
+					removed = true;
+				}
+				if (removed) {
+					ft.commitNowAllowingStateLoss();
+				}
+			}
+		}
+
 		// Try to get the rootViewId form the saved state in case the activity
 		// was destroyed and we are now recreating it.
 		if (savedInstanceState) {

Original file line number	Diff line number	Diff line change
`@@ -29,7 +29,6 @@ export class ActionBarBase extends View implements ActionBarDefinition {`
`29`	`29`	`public effectiveContentInsetRight: number;`
`30`	`30`
`31`	`31`	`disposeNativeView() {`
`32`		`- this._actionItems = null;`
`33`	`32`	`super.disposeNativeView();`
`34`	`33`	`}`
`35`	`34`