Adds current_with_activation_height() method and uses it in Commitment::from_bytes()

Author: arya2

zebra-chain/src/block/commitment.rs

@@ -109,24 +109,34 @@ impl Commitment {
         use Commitment::*;
         use CommitmentError::*;
 
-        match NetworkUpgrade::current(network, height) {
-            Genesis | BeforeOverwinter | Overwinter => Ok(PreSaplingReserved(bytes)),
-            Sapling | Blossom => match sapling::tree::Root::try_from(bytes) {
+        match NetworkUpgrade::current_with_activation_height(network, height) {
+            (Genesis | BeforeOverwinter | Overwinter, _) => Ok(PreSaplingReserved(bytes)),
+            (Sapling | Blossom, _) => match sapling::tree::Root::try_from(bytes) {
                 Ok(root) => Ok(FinalSaplingRoot(root)),
                 _ => Err(InvalidSapingRootBytes),
             },
+            (Heartwood, activation_height) if height == activation_height => {
+                if bytes == CHAIN_HISTORY_ACTIVATION_RESERVED {
+                    Ok(ChainHistoryActivationReserved)
+                } else {
+                    Err(InvalidChainHistoryActivationReserved { actual: bytes })
+                }
+            }
             // NetworkUpgrade::current() returns the latest network upgrade that's activated at the provided height, so
             // on Regtest for heights above height 0, it returns NU5, and it's possible for the current network upgrade
             // to be NU5 (or Canopy, or any network upgrade above Heartwood) at the Heartwood activation height.
-            Heartwood | Canopy | Nu5 if Some(height) == Heartwood.activation_height(network) => {
+            (Canopy | Nu5, activation_height)
+                if height == activation_height
+                    && Some(height) == Heartwood.activation_height(network) =>
+            {
                 if bytes == CHAIN_HISTORY_ACTIVATION_RESERVED {
                     Ok(ChainHistoryActivationReserved)
                 } else {
                     Err(InvalidChainHistoryActivationReserved { actual: bytes })
                 }
             }
-            Heartwood | Canopy => Ok(ChainHistoryRoot(ChainHistoryMmrRootHash(bytes))),
-            Nu5 => Ok(ChainHistoryBlockTxAuthCommitment(
+            (Heartwood | Canopy, _) => Ok(ChainHistoryRoot(ChainHistoryMmrRootHash(bytes))),
+            (Nu5, _) => Ok(ChainHistoryBlockTxAuthCommitment(
                 ChainHistoryBlockTxAuthCommitmentHash(bytes),
             )),
         }

zebra-chain/src/parameters/network_upgrade.rs

@@ -280,6 +280,19 @@ impl Network {
 }
 
 impl NetworkUpgrade {
+    /// Returns the current network upgrade and its activation height for `network` and `height`.
+    pub fn current_with_activation_height(
+        network: &Network,
+        height: block::Height,
+    ) -> (NetworkUpgrade, block::Height) {
+        network
+            .activation_list()
+            .range(..=height)
+            .map(|(&h, &nu)| (nu, h))
+            .next_back()
+            .expect("every height has a current network upgrade")
+    }
+
     /// Returns the current network upgrade for `network` and `height`.
     pub fn current(network: &Network, height: block::Height) -> NetworkUpgrade {
         network