From 07dbfbef591d39029afef1ae84b52dab116fd0c3 Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Mon, 3 Jun 2019 11:14:01 +0100
Subject: [PATCH] Address Eirik's review comments

---
 zcash_primitives/src/merkle_tree.rs | 8 ++++----
 zcash_primitives/src/serialize.rs   | 1 +
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/zcash_primitives/src/merkle_tree.rs b/zcash_primitives/src/merkle_tree.rs
index 2dcc5cc..e48f8ee 100644
--- a/zcash_primitives/src/merkle_tree.rs
+++ b/zcash_primitives/src/merkle_tree.rs
@@ -90,10 +90,10 @@ impl<Node: Hashable> CommitmentTree<Node> {
     /// Returns the number of notes in the tree.
     pub fn size(&self) -> usize {
         self.parents.iter().enumerate().fold(
-            match (self.left.is_some(), self.right.is_some()) {
-                (false, false) => 0,
-                (true, false) | (false, true) => 1,
-                (true, true) => 2,
+            match (self.left, self.right) {
+                (None, None) => 0,
+                (Some(_), None) | (None, Some(_)) => 1,
+                (Some(_), Some(_)) => 2,
             },
             |acc, (i, p)| {
                 // Treat occupation of parents array as a binary number
diff --git a/zcash_primitives/src/serialize.rs b/zcash_primitives/src/serialize.rs
index 8312312..41778dc 100644
--- a/zcash_primitives/src/serialize.rs
+++ b/zcash_primitives/src/serialize.rs
@@ -221,6 +221,7 @@ mod tests {
         eval_u8!(Some(1), [1, 1]);
         eval_u8!(Some(5), [1, 5]);
 
+        eval_vec!(None as Option<Vec<_>>, [0]);
         eval_vec!(Some(vec![]), [1, 0]);
         eval_vec!(Some(vec![0]), [1, 1, 0]);
         eval_vec!(Some(vec![1]), [1, 1, 1]);