Leave a view untransformed on iOS when its transform is not finite

packages/react-native/React/Fabric/RCTConversions.h

@@ -5,6 +5,8 @@
  * LICENSE file in the root directory of this source tree.
  */
 
+#import <cmath>
+
 #import <UIKit/UIKit.h>
 
 #import <React/Graphics.h>
@@ -152,6 +154,12 @@ inline UIAccessibilityTraits RCTUIAccessibilityTraitsFromAccessibilityTraits(
 
 inline CATransform3D RCTCATransform3DFromTransformMatrix(const facebook::react::Transform &transformMatrix)
 {
+  // Core Animation needs a finite transform: a NaN in one hides the layer and can hide its siblings.
+  for (const auto value : transformMatrix.matrix) {
+    if (!std::isfinite(value)) {
+      return CATransform3DIdentity;
+    }
+  }
   return {
       (CGFloat)transformMatrix.matrix[0],
       (CGFloat)transformMatrix.matrix[1],

packages/react-native/React/Tests/Mounting/RCTViewComponentViewTests.mm

@@ -204,6 +204,39 @@ - (void)testHitTestAfterScaleTransitionedToZeroReturnsNil
   XCTAssertNil([view hitTest:CGPointMake(50, 50) withEvent:nil]);
 }
 
+#pragma mark - non-finite transforms
+
+static RCTViewComponentView *makeViewWithTransform(const Transform &transform)
+{
+  RCTViewComponentView *view = [RCTViewComponentView new];
+  auto props = std::make_shared<ViewProps>();
+  props->transform = transform;
+  [view updateProps:props oldProps:ViewShadowNode::defaultSharedProps()];
+  return view;
+}
+
+- (void)testFiniteTransformIsApplied
+{
+  RCTViewComponentView *view = makeViewWithTransform(Transform::Translate(5, 10, 0));
+
+  XCTAssertEqual(view.layer.transform.m41, 5.0);
+  XCTAssertEqual(view.layer.transform.m42, 10.0);
+}
+
+- (void)testTransformWithNaNIsNotApplied
+{
+  RCTViewComponentView *view = makeViewWithTransform(Transform::Translate(NAN, 10, 0));
+
+  XCTAssertTrue(CATransform3DIsIdentity(view.layer.transform));
+}
+
+- (void)testTransformWithInfinityIsNotApplied
+{
+  RCTViewComponentView *view = makeViewWithTransform(Transform::Scale(INFINITY, 1, 1));
+
+  XCTAssertTrue(CATransform3DIsIdentity(view.layer.transform));
+}
+
 #pragma mark - Full Keyboard Access focusability
 
 static RCTViewComponentView *makeViewWithRole(bool accessible, const std::string &accessibilityRole)