fix: ensure each ref maps to a single commit

Signed-off-by: MYUU <[email protected]>

Author: zhoujiaqi30

ceres/src/api_service/mono_api_service.rs

@@ -1183,13 +1183,25 @@ impl MonoApiService {
                 );
                 let commit_id = commit.id.to_string();
                 new_commit_id = commit_id.clone();
+
+                // Construct a commit record without a parent commit
+                // For details, refer to the `head_hash` method invoked when cloning a repository.
+                let c: Commit = Commit::new(
+                    commit.author.clone(),
+                    commit.committer.clone(),
+                    update.tree_id,
+                    vec![],
+                    &commit.message,
+                );
+
                 commits.push(commit);
+                commits.push(c.clone());
 
                 let mut push_update = |ref_name: &str| {
                     updates.push(RefUpdateData {
                         path: p_ref.path.clone(),
                         ref_name: ref_name.to_string(),
-                        commit_id: commit_id.clone(),
+                        commit_id: c.id.to_string().clone(),
                         tree_hash: update.tree_id.to_string(),
                     });
                 };