Ensure headers are maintained when converting manifests

Signed-off-by: Ryan Bottriell <ryan@bottriell.ca>

crates/spfs/src/graph/manifest.rs

@@ -112,7 +112,11 @@ impl Manifest {
         }
 
         iter_tree(self, self.root(), &mut root);
-        tracking::Manifest::new(root)
+        let mut manifest = tracking::Manifest::new(root);
+        // ensure that the manifest will round-trip in the case of it
+        // being converted back into this type
+        manifest.set_header(self.header().to_owned());
+        manifest
     }
 
     pub(super) fn legacy_encode(&self, mut writer: &mut impl std::io::Write) -> Result<()> {

crates/spfs/src/graph/object.rs

@@ -539,6 +539,16 @@ impl std::fmt::Debug for Header {
     }
 }
 
+impl std::borrow::ToOwned for Header {
+    type Owned = HeaderBuf;
+
+    fn to_owned(&self) -> Self::Owned {
+        let mut buf = HeaderBuf(Default::default());
+        buf.0[..].clone_from_slice(&self.0);
+        buf
+    }
+}
+
 impl std::ops::Deref for Header {
     type Target = [u8];
 
@@ -638,6 +648,12 @@ impl std::ops::Deref for HeaderBuf {
     }
 }
 
+impl std::borrow::Borrow<Header> for HeaderBuf {
+    fn borrow(&self) -> &Header {
+        self
+    }
+}
+
 impl AsRef<Header> for HeaderBuf {
     #[inline]
     fn as_ref(&self) -> &Header {

crates/spfs/src/tracking/manifest.rs

@@ -90,8 +90,12 @@ impl<T> Manifest<T> {
         }
     }
 
+    pub fn header(&self) -> &graph::object::Header {
+        &self.header
+    }
+
     pub fn set_header(&mut self, mut header: graph::object::HeaderBuf) {
-        // an different object kind would cause bugs and should never be allowed
+        // a different object kind would cause bugs and should never be allowed
         header.set_object_kind(graph::ObjectKind::Manifest);
         self.header = header;
     }

crates/spk-build/src/build/binary.rs

@@ -886,6 +886,9 @@ fn split_manifest_by_component(
     let mut manifests = HashMap::with_capacity(components.len());
     for component in components.iter() {
         let mut component_manifest = spfs::tracking::Manifest::default();
+        // ensure we are storing things with the same settings as the
+        // original manifest that was generated by the build
+        component_manifest.set_header(manifest.header().to_owned());
 
         // identify all the file paths that we will replicate
         // first so that we can also identify necessary