Missed a thing

src/inventory/item.rs

@@ -1,5 +1,6 @@
 use crate::keypath::KeyPath;
 use crate::s3::S3Location;
+use crate::util::make_old_filename;
 use time::OffsetDateTime;
 
 /// An entry in an inventory list file
@@ -75,6 +76,14 @@ impl InventoryItem {
     pub(crate) fn is_deleted(&self) -> bool {
         self.details == ItemDetails::Deleted
     }
+
+    pub(crate) fn old_filename(&self) -> Option<String> {
+        let ItemDetails::Present { ref etag, .. } = self.details else {
+            return None;
+        };
+        (!self.is_deleted() && !self.is_latest)
+            .then(|| make_old_filename(self.key.name(), &self.version_id, etag))
+    }
 }
 
 /// Metadata about an object's content

src/keypath.rs

@@ -15,6 +15,13 @@ use thiserror::Error;
 pub(crate) struct KeyPath(String);
 
 impl KeyPath {
+    pub(crate) fn name(&self) -> &str {
+        self.0
+            .split('/')
+            .next_back()
+            .expect("path should be nonempty")
+    }
+
     /// Split the path into the directory component (if any) and filename
     pub(crate) fn split(&self) -> (Option<&str>, &str) {
         match self.0.rsplit_once('/') {

src/syncer/metadata.rs

@@ -1,4 +1,5 @@
 use super::*;
+use crate::util::make_old_filename;
 use serde::{Deserialize, Serialize};
 use std::io::ErrorKind;
 
@@ -17,7 +18,7 @@ impl Metadata {
     /// `self` as its metadata and `basename` as the filename portion of its
     /// key
     pub(super) fn old_filename(&self, basename: &str) -> String {
-        format!("{}.old.{}.{}", basename, self.version_id, self.etag)
+        make_old_filename(basename, &self.version_id, &self.etag)
     }
 }
 

src/syncer/mod.rs

@@ -147,7 +147,7 @@ impl Syncer {
                             InventoryEntry::Item(item) => {
                                 let notify = if !item.is_deleted() {
                                     let notify = Arc::new(Notify::new());
-                                    for dir in tracker.add(&item.key, notify.clone(), None)? {
+                                    for dir in tracker.add(&item.key, notify.clone(), item.old_filename())? {
                                         subnursery.spawn({
                                             this.until_cancelled_ok({
                                                 let this = this.clone();

src/util.rs

@@ -113,6 +113,10 @@ pub(crate) fn force_create_dir_all<I: IntoIterator<Item: AsRef<Path>>>(
     Ok(())
 }
 
+pub(crate) fn make_old_filename(basename: &str, version_id: &str, etag: &str) -> String {
+    format!("{basename}.old.{version_id}.{etag}")
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;