Prevent RCTScreenSize from caching a zero screen size

Author: zoontek

packages/react-native/React/Base/RCTUtils.mm

@@ -384,13 +384,13 @@ UIDeviceOrientation RCTDeviceOrientation(void)
 CGSize RCTScreenSize(void)
 {
   static CGSize portraitSize;
-  static dispatch_once_t onceToken;
-  dispatch_once(&onceToken, ^{
+
+  if (CGSizeEqualToSize(portraitSize, CGSizeZero)) {
     RCTUnsafeExecuteOnMainQueueSync(^{
       CGSize screenSize = [UIScreen mainScreen].bounds.size;
       portraitSize = CGSizeMake(MIN(screenSize.width, screenSize.height), MAX(screenSize.width, screenSize.height));
     });
-  });
+  }
 
 #if !TARGET_OS_TV
   if (UIDeviceOrientationIsLandscape(RCTDeviceOrientation())) {

packages/react-native/ReactCommon/react/renderer/components/modal/ModalHostViewUtils.mm

@@ -13,16 +13,8 @@
 
 Size ModalHostViewScreenSize(void)
 {
-  __block CGSize viewportSize;
-
-  RCTUnsafeExecuteOnMainQueueSync(^{
-    viewportSize = RCTViewportSize();
-  });
-
-  return {
-    .width = viewportSize.width,
-    .height = viewportSize.height,
-  };
+  CGSize screenSize = RCTScreenSize();
+  return {.width = screenSize.width, .height = screenSize.height};
 }
 
 } // namespace facebook::react