diff --git a/src/command/maintenance.rs b/src/command/maintenance.rs
index 29e63b33b..00fa97d15 100644
--- a/src/command/maintenance.rs
+++ b/src/command/maintenance.rs
@@ -59,6 +59,12 @@ const MAINTENANCE_LAST_RUN_KEY: &str = "maintenance.last-run";
 const DEFAULT_LOOSE_OBJECT_THRESHOLD: usize = 100;
 const DEFAULT_PACK_COUNT_THRESHOLD: usize = 5;
 const LOOSE_OBJECT_AGE_SECONDS: u64 = 14 * 24 * 60 * 60; // 2 weeks
+/// Grace period before an unreachable loose object may be deleted by `gc`.
+///
+/// This protects concurrent commands (add/commit/fetch/hash-object) that have
+/// just written objects but not yet updated refs/reflogs/index. Objects newer
+/// than this grace period are left in place even when unreachable.
+const GC_PRUNE_GRACE_SECONDS: u64 = 60 * 60; // 1 hour
 
 /// `--help` examples shown in `libra maintenance --help` output.
 pub const MAINTENANCE_EXAMPLES: &str = "\
diff --git a/src/command/stash.rs b/src/command/stash.rs
index c7ceb5469..95ecbc8e4 100644
--- a/src/command/stash.rs
+++ b/src/command/stash.rs
@@ -340,7 +340,11 @@ async fn run_push(options: StashPushOptions) -> Result<StashOutput, StashError>
 
     let index_tree =
         tree::create_tree_from_index(&index).map_err(|e| StashError::WriteObject(e.to_string()))?;
-    let index_tree_hash = index_tree.id;
+    let index_tree_data = index_tree
+        .to_data()
+        .map_err(|e| StashError::WriteObject(e.to_string()))?;
+    let index_tree_hash = object::write_git_object(&git_dir, "tree", &index_tree_data)
+        .map_err(|e| StashError::WriteObject(e.to_string()))?;
 
     let (author, committer) = util::create_signatures().await;
     let (current_branch_name, head_commit_summary) = match Head::current().await {