From 5a9ed11c258170855fb17c9c2bdd8944b550f4b0 Mon Sep 17 00:00:00 2001
From: Rene Vergara <rene@vergara.network>
Date: Fri, 18 Oct 2024 12:25:30 -0500
Subject: [PATCH] fix(rust): SaplingFrontier marshalling

---
 librustzcash-wrapper/src/lib.rs | 46 ++++++++++-----------------------
 1 file changed, 14 insertions(+), 32 deletions(-)

diff --git a/librustzcash-wrapper/src/lib.rs b/librustzcash-wrapper/src/lib.rs
index 3209737..92e9319 100644
--- a/librustzcash-wrapper/src/lib.rs
+++ b/librustzcash-wrapper/src/lib.rs
@@ -1403,39 +1403,21 @@ pub extern "C" fn rust_wrapper_read_sapling_commitment_tree(
     out: *mut u8,
     out_len: &mut usize
     ){
-    let tree_in: Vec<u8> = marshall_from_haskell_var(tree, tree_len, RW);
-    let tree_reader = Cursor::new(tree_in);
-    let mut ct = read_commitment_tree::<Node, Cursor<Vec<u8>>, SAPLING_DEPTH>(tree_reader);
-    match ct {
-        Ok(mut comm_tree) => {
-            let node_in: Vec<u8> = marshall_from_haskell_var(node, node_len, RW);
-            let sap_note_comm = SaplingNoteCommitment::from_bytes(&to_array(node_in));
-            if sap_note_comm.is_some().into() {
-                let n = Node::from_cmu(&sap_note_comm.unwrap());
-                comm_tree.append(n);
-                let mut out_bytes: Vec<u8> = Vec::new();
-                let result = write_commitment_tree(&comm_tree, &mut out_bytes );
-                match result {
-                    Ok(()) => {
-                        let h = Hhex { bytes: out_bytes};
-                        marshall_to_haskell_var(&h, out, out_len, RW);
-                    },
-                    Err(_e) => {
-                        let h0 = Hhex { bytes: vec![0]};
-                        marshall_to_haskell_var(&h0, out, out_len, RW);
-                    }
-                }
-            } else {
-                let h0 = Hhex { bytes: vec![0]};
-                marshall_to_haskell_var(&h0, out, out_len, RW);
-            }
-        },
-        Err(_e) => {
-            let h0 = Hhex { bytes: vec![0]};
-            marshall_to_haskell_var(&h0, out, out_len, RW);
-        }
+    let tree_in: Hfrontier = marshall_from_haskell_var(tree, tree_len, RW);
+    let leaf = Node::from_bytes(to_array(tree_in.leaf.bytes)).unwrap();
+    let mut comm_tree = NonEmptyFrontier::from_parts(Position::from(tree_in.position), leaf, tree_in.ommers.iter().map(|x| Node::from_bytes(to_array(x.clone())).unwrap() ).collect()).unwrap();
+    let node_in: Vec<u8> = marshall_from_haskell_var(node, node_len, RW);
+    let sap_note_comm = SaplingNoteCommitment::from_bytes(&to_array(node_in));
+    if sap_note_comm.is_some().into() {
+        let n = Node::from_cmu(&sap_note_comm.unwrap());
+        comm_tree.append(n);
+        let (pos, leaf, omm) = comm_tree.into_parts();
+        let f = Hfrontier { position: <u64>::from(pos), leaf: Hhex { bytes: leaf.to_bytes().to_vec()}, ommers: omm.iter().map(|&x| x.to_bytes().to_vec()).collect()};
+        marshall_to_haskell_var(&f, out, out_len, RW);
+    } else {
+        let f0 = Hfrontier { position: 0, leaf: Hhex { bytes: vec![0]}, ommers: vec![vec![0]]};
+        marshall_to_haskell_var(&f0, out, out_len, RW);
     }
-
 }
 
 #[no_mangle]