Zingo sync retain relevant blocks

zingo-sync/src/sync.rs

@@ -239,7 +239,7 @@ where
 
 fn remove_irrelevant_data<W>(wallet: &mut W, scan_range: &ScanRange) -> Result<(), ()>
 where
-    W: SyncWallet + SyncBlocks + SyncNullifiers,
+    W: SyncWallet + SyncBlocks + SyncNullifiers + SyncTransactions,
 {
     if scan_range.priority() != ScanPriority::Historic {
         return Ok(());
@@ -254,9 +254,16 @@ where
         .block_range()
         .end;
 
-    // TODO: also retain blocks that contain transactions relevant to the wallet
+    let wallet_transaction_heights = wallet
+        .get_wallet_transactions()
+        .unwrap()
+        .values()
+        .map(|tx| tx.block_height())
+        .collect::<Vec<_>>();
     wallet.get_wallet_blocks_mut().unwrap().retain(|height, _| {
-        *height >= scan_range.block_range().end || *height >= wallet_height.saturating_sub(100)
+        *height >= scan_range.block_range().end
+            || *height >= wallet_height.saturating_sub(100)
+            || wallet_transaction_heights.contains(height)
     });
     wallet
         .get_nullifiers_mut()

zingo-sync/src/traits.rs

@@ -57,6 +57,9 @@ pub trait SyncBlocks: SyncWallet {
 
 /// Trait for interfacing [`crate::primitives::WalletTransaction`]s with wallet data
 pub trait SyncTransactions: SyncWallet {
+    /// Get reference to wallet transactions
+    fn get_wallet_transactions(&self) -> Result<&HashMap<TxId, WalletTransaction>, Self::Error>;
+
     /// Get mutable reference to wallet transactions
     fn get_wallet_transactions_mut(
         &mut self,

zingolib/src/wallet/sync.rs

@@ -68,6 +68,15 @@ impl SyncBlocks for LightWallet {
 }
 
 impl SyncTransactions for LightWallet {
+    fn get_wallet_transactions(
+        &self,
+    ) -> Result<
+        &HashMap<zcash_primitives::transaction::TxId, zingo_sync::primitives::WalletTransaction>,
+        Self::Error,
+    > {
+        Ok(self.wallet_transactions())
+    }
+
     fn get_wallet_transactions_mut(
         &mut self,
     ) -> Result<