From 02341ece264d189cbdfe17210246937d68c03d13 Mon Sep 17 00:00:00 2001
From: Kris Nuttycombe <kris@nutty.land>
Date: Mon, 27 Mar 2023 09:54:21 -0600
Subject: [PATCH] Ensure that `BridgeTree` state is checkpointed when
 constructing from a frontier.

---
 bridgetree/src/lib.rs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/bridgetree/src/lib.rs b/bridgetree/src/lib.rs
index 7cba360..151e8ce 100644
--- a/bridgetree/src/lib.rs
+++ b/bridgetree/src/lib.rs
@@ -536,8 +536,8 @@ impl<H, C, const DEPTH: u8> BridgeTree<H, C, DEPTH> {
 impl<H: Hashable + Ord + Clone, C: Clone + Ord, const DEPTH: u8> BridgeTree<H, C, DEPTH> {
     /// Construct a new BridgeTree that will start recording changes from the state of
     /// the specified frontier.
-    pub fn from_frontier(max_checkpoints: usize, frontier: NonEmptyFrontier<H>) -> Self {
-        Self {
+    pub fn from_frontier(max_checkpoints: usize, frontier: NonEmptyFrontier<H>, checkpoint_id: C) -> Self {
+        let mut bridge = Self {
             prior_bridges: vec![],
             current_bridge: Some(MerkleBridge::from_parts(
                 None,
@@ -548,7 +548,9 @@ impl<H: Hashable + Ord + Clone, C: Clone + Ord, const DEPTH: u8> BridgeTree<H, C
             saved: BTreeMap::new(),
             checkpoints: VecDeque::new(),
             max_checkpoints,
-        }
+        };
+        bridge.checkpoint(checkpoint_id);
+        bridge
     }
 
     /// Construct a new BridgeTree from its constituent parts, checking for internal