From 3c6fda8e0be63bd7b63adcd78007706d95fe69f9 Mon Sep 17 00:00:00 2001
From: Henry de Valence <hdevalence@hdevalence.ca>
Date: Fri, 7 Feb 2020 09:21:23 -0800
Subject: [PATCH] Make the BlockHeaderHash conversions work on borrows.

---
 zebra-chain/src/block.rs       | 10 ++++++++--
 zebra-chain/src/block/tests.rs |  2 +-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/zebra-chain/src/block.rs b/zebra-chain/src/block.rs
index 906a69d2..dfe7bba7 100644
--- a/zebra-chain/src/block.rs
+++ b/zebra-chain/src/block.rs
@@ -43,8 +43,8 @@ impl fmt::Debug for BlockHeaderHash {
     }
 }
 
-impl From<BlockHeader> for BlockHeaderHash {
-    fn from(block_header: BlockHeader) -> Self {
+impl<'a> From<&'a BlockHeader> for BlockHeaderHash {
+    fn from(block_header: &'a BlockHeader) -> Self {
         let mut hash_writer = Sha256dWriter::default();
         block_header
             .zcash_serialize(&mut hash_writer)
@@ -169,6 +169,12 @@ pub struct Block {
     pub transactions: Vec<Transaction>,
 }
 
+impl<'a> From<&'a Block> for BlockHeaderHash {
+    fn from(block: &'a Block) -> BlockHeaderHash {
+        (&block.header).into()
+    }
+}
+
 impl ZcashSerialize for Block {
     fn zcash_serialize<W: io::Write>(&self, mut writer: W) -> Result<(), io::Error> {
         self.header.zcash_serialize(&mut writer)?;
diff --git a/zebra-chain/src/block/tests.rs b/zebra-chain/src/block/tests.rs
index d6efbe27..24476f2e 100644
--- a/zebra-chain/src/block/tests.rs
+++ b/zebra-chain/src/block/tests.rs
@@ -77,7 +77,7 @@ fn blockheaderhash_from_blockheader() {
         solution: EquihashSolution([0; 1344]),
     };
 
-    let hash = BlockHeaderHash::from(blockheader);
+    let hash = BlockHeaderHash::from(&blockheader);
 
     assert_eq!(
         format!("{:?}", hash),