Prevent TapTree from hidden parts

src/util/psbt/map/output.rs

@@ -143,6 +143,8 @@ impl TapTree {
     pub fn from_inner(inner: TaprootBuilder) -> Result<Self, IncompleteTapTree> {
         if !inner.is_finalized() {
             Err(IncompleteTapTree::NotFinalized(inner))
+        } else if inner.has_hidden_nodes() {
+            Err(IncompleteTapTree::HiddenParts(inner))
         } else {
             Ok(TapTree(inner))
         }

src/util/psbt/serialize.rs

@@ -355,7 +355,7 @@ impl Deserialize for TapTree {
             builder = builder.add_leaf_with_ver(*depth, script, leaf_version)
                 .map_err(|_| encode::Error::ParseFailed("Tree not in DFS order"))?;
         }
-        if builder.is_finalized() {
+        if builder.is_finalized() || !builder.has_hidden_nodes() {
             Ok(TapTree(builder))
         } else {
             Err(encode::Error::ParseFailed("Incomplete taproot Tree"))