Keep current block randomness in state

frame/babe/src/lib.rs

@@ -256,9 +256,10 @@ pub mod pallet {
 	#[pallet::getter(fn initialized)]
 	pub(super) type Initialized<T> = StorageValue<_, MaybeRandomness>;
 
-	/// Temporary value (cleared at block finalization) that includes the VRF output generated
-	/// at this block. This field should always be populated during block processing unless
+	/// This field should always be populated during block processing unless
 	/// secondary plain slots are enabled (which don't contain a VRF output).
+	///
+	/// It is set in `on_initialize`, before it will contain the value from the last block.
 	#[pallet::storage]
 	#[pallet::getter(fn author_vrf_randomness)]
 	pub(super) type AuthorVrfRandomness<T> = StorageValue<_, MaybeRandomness, ValueQuery>;
@@ -337,9 +338,6 @@ pub mod pallet {
 				Self::deposit_randomness(&randomness);
 			}
 
-			// The stored author generated VRF output is ephemeral.
-			AuthorVrfRandomness::<T>::kill();
-
 			// remove temporary "environment" entry from storage
 			Lateness::<T>::kill();
 		}

frame/babe/src/tests.rs

@@ -95,7 +95,7 @@ fn first_block_epoch_zero_start() {
 		assert_eq!(SegmentIndex::<Test>::get(), 0);
 		assert_eq!(UnderConstruction::<Test>::get(0), vec![vrf_randomness]);
 		assert_eq!(Babe::randomness(), [0; 32]);
-		assert_eq!(Babe::author_vrf_randomness(), None);
+		assert_eq!(Babe::author_vrf_randomness(), Some(vrf_randomness));
 		assert_eq!(NextRandomness::<Test>::get(), [0; 32]);
 
 		assert_eq!(header.digest.logs.len(), 2);
@@ -130,14 +130,13 @@ fn author_vrf_output_for_primary() {
 			&primary_pre_digest,
 			Default::default(),
 		);
-		assert_eq!(Babe::author_vrf_randomness(), None);
 
 		Babe::do_initialize(1);
 		assert_eq!(Babe::author_vrf_randomness(), Some(vrf_randomness));
 
 		Babe::on_finalize(1);
 		System::finalize();
-		assert_eq!(Babe::author_vrf_randomness(), None);
+		assert_eq!(Babe::author_vrf_randomness(), Some(vrf_randomness));
 	})
 }
 
@@ -156,14 +155,13 @@ fn author_vrf_output_for_secondary_vrf() {
 			&secondary_vrf_pre_digest,
 			Default::default(),
 		);
-		assert_eq!(Babe::author_vrf_randomness(), None);
 
 		Babe::do_initialize(1);
 		assert_eq!(Babe::author_vrf_randomness(), Some(vrf_randomness));
 
 		Babe::on_finalize(1);
 		System::finalize();
-		assert_eq!(Babe::author_vrf_randomness(), None);
+		assert_eq!(Babe::author_vrf_randomness(), Some(vrf_randomness));
 	})
 }