Create RefValue container

ugit/base.py

@@ -84,7 +84,7 @@ def read_tree(tree_oid):
 def commit(message):
     commit = f"tree {write_tree()}\n"
 
-    HEAD = data.get_ref("HEAD")
+    HEAD = data.get_ref("HEAD").value
     if HEAD:
         commit += f"parent {HEAD}\n"
 
@@ -93,23 +93,23 @@ def commit(message):
 
     oid = data.hash_object(commit.encode(), "commit")
 
-    data.update_ref("HEAD", oid)
+    data.update_ref("HEAD", data.RefValue(symbolic=False, value=oid))
 
     return oid
 
 
 def create_tag(name, oid):
-    data.update_ref(f"refs/tags/{name}", oid)
+    data.update_ref(f"refs/tags/{name}", data.RefValue(symbolic=False, value=oid))
 
 
 def checkout(oid):
     commit = get_commit(oid)
     read_tree(commit.tree)
-    data.update_ref("HEAD", oid)
+    data.update_ref("HEAD", data.RefValue(symbolic=False, value=oid))
 
 
 def create_branch(name, oid):
-    data.update_ref(f"refs/heads/{name}", oid)
+    data.update_ref(f"refs/heads/{name}", data.RefValue(symbolic=False, value=oid))
 
 
 Commit = namedtuple("Commit", ["tree", "parent", "message"])
@@ -161,8 +161,8 @@ def get_oid(name):
         f"refs/heads/{name}",
     ]
     for ref in refs_to_try:
-        if data.get_ref(ref):
-            return data.get_ref(ref)
+        if data.get_ref(ref).value:
+            return data.get_ref(ref).value
 
     # Name is SHA1
     is_hex = all(c in string.hexdigits for c in name)