Fix IllegalStateException: Required value was null. (#11293)

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

patches/react-native@0.81.5.patch

@@ -60,7 +60,7 @@ index 0d231bc8aa938da296eb3b981e8ac9595a43b87f..be0a10d9c4de1892fa00bcbf8d63d739
  
    if (newConcreteProps.tintColor != oldConcreteProps.tintColor) {
 diff --git a/React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.mm b/React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.mm
-index 1494fd225aff1fa0429e917404d6b4ca5fc961c5..682e41b141c38c830bbcd9f2ce0de07b18f13977 100644
+index 1494fd225aff1fa0429e917404d6b4ca5fc961c5..d0cce700090245444f8ce51e517d5ceca09526f6 100644
 --- a/React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.mm
 +++ b/React/Fabric/Mounting/ComponentViews/ScrollView/RCTScrollViewComponentView.mm
 @@ -380,7 +380,15 @@ - (void)updateProps:(const Props::Shared &)props oldProps:(const Props::Shared &
@@ -224,6 +224,35 @@ index 8b6571698fc5dd091a0d8980a33bb40295faf305..27c97bfeb6f13907c89f1d85f2bb8b8a
        reactChoreographer.postFrameCallback(ReactChoreographer.CallbackType.IDLE_EVENT, this)
      }
    }
+diff --git a/ReactAndroid/src/main/java/com/facebook/react/views/view/ReactViewGroup.kt b/ReactAndroid/src/main/java/com/facebook/react/views/view/ReactViewGroup.kt
+index 89b666dcf0258df0702c812600b685463128294c..2b1c3971f0c31a0d7a592b90170e4cc53a8a69dd 100644
+--- a/ReactAndroid/src/main/java/com/facebook/react/views/view/ReactViewGroup.kt
++++ b/ReactAndroid/src/main/java/com/facebook/react/views/view/ReactViewGroup.kt
+@@ -431,6 +431,13 @@ public open class ReactViewGroup public constructor(context: Context?) :
+     inSubviewClippingLoop = true
+     var clippedSoFar = 0
+     for (i in 0..<allChildrenCount) {
++      // Reentrant child removal during this loop can compact allChildren and leave a null at
++      // an index below allChildrenCount. A null entry means the view is already detached, so
++      // treat it as clipped instead of crashing.
++      if (childArray[i] == null) {
++        clippedSoFar++
++        continue
++      }
+       try {
+         updateSubviewClipStatus(clippingRect, i, clippedSoFar, excludedViewsSet)
+       } catch (ex: IndexOutOfBoundsException) {
+@@ -466,7 +473,9 @@ public open class ReactViewGroup public constructor(context: Context?) :
+   ) {
+     assertOnUiThread()
+ 
+-    val child = checkNotNull(allChildren?.get(idx))
++    // allChildren can be mutated reentrantly while a clipping pass is running, so a stale
++    // index can point at a null slot. Skip it instead of crashing.
++    val child = allChildren?.get(idx) ?: return
+     val intersects = clippingRect.intersects(child.left, child.top, child.right, child.bottom)
+     var needUpdateClippingRecursive = false
+ 
 diff --git a/ReactCommon/react/renderer/textlayoutmanager/platform/ios/react/renderer/textlayoutmanager/RCTTextLayoutManager.mm b/ReactCommon/react/renderer/textlayoutmanager/platform/ios/react/renderer/textlayoutmanager/RCTTextLayoutManager.mm
 index 216bb23beb023ef6c3ae814c17e05bccbda7fc91..6ad5cc1d9ed5b8cd2df08ad77adca56c6bb58ff4 100644
 --- a/ReactCommon/react/renderer/textlayoutmanager/platform/ios/react/renderer/textlayoutmanager/RCTTextLayoutManager.mm

patches/react-native@0.81.5.patch.md

@@ -65,6 +65,33 @@ content-less area are attributed to the `UIScrollView`.
 Issue: https://github.com/facebook/react-native/issues/54123
 PR: https://github.com/react/react-native/pull/56747
 
+## ReactViewGroup.kt Patch - Fatal "Required value was null" during subview clipping on Android
+
+Fixes Sentry issue APP-T20Q: `IllegalStateException: Required value was null` thrown by
+`checkNotNull(allChildren?.get(idx))` in `updateSubviewClipStatus`, reached from
+`ReactScrollView.onScrollChanged -> updateClippingRect` during an animated smooth scroll
+(New Architecture, `removeClippedSubviews`).
+
+The clipping loop in `updateClippingToRect` captures its bound once, but clipping a view
+(`removeViewsInLayout`) can synchronously trigger reentrant child removal (layout-change
+listeners, animation-end callbacks, Fabric mounting on the UI thread), which compacts
+`allChildren` and nulls the tail mid-loop. Upstream already catches the
+`IndexOutOfBoundsException` variant of this corruption with diagnostics, but the null-child
+variant throws `IllegalStateException` and escapes as a fatal crash. A null entry means the
+view is already detached, so we skip it and count it as clipped to keep index math aligned.
+
+Not fixed upstream as of July 2026 (identical `checkNotNull` on `main`); the sibling fix
+attempt facebook/react-native#57365 for the same bookkeeping corruption (different stack)
+was abandoned. Re-check when bumping React Native.
+
+Note on build modes: production Android builds compile react-android from source
+(`buildReactNativeFromSource: IS_PRODUCTION` via expo-build-properties in app.config.js
+injects the includeBuild/dependency-substitution block at prebuild), so this hunk IS
+active in production releases. Local dev builds prebuilt in a non-production env consume
+the prebuilt AAR from Maven Central instead, where this hunk (like any ReactAndroid
+source change) has no effect - do not expect to see the fix in a local debug build unless
+you prebuild with EXPO_PUBLIC_ENV=production or add the substitution block manually.
+
 ## RCTTextLayoutManager.mm Patch - Text overflows instead of wrapping on the last line
 
 Issue: https://github.com/react/react-native/issues/53450#issuecomment-3298157830