Set parent to HEAD

ugit/base.py

@@ -78,6 +78,11 @@ def read_tree(tree_oid):
 
 def commit(message):
     commit = f"tree {write_tree()}\n"
+
+    HEAD = data.get_HEAD()
+    if HEAD:
+        commit += f"parent {HEAD}\n"
+
     commit += "\n"
     commit += f"{message}\n"
 

ugit/data.py

@@ -15,6 +15,12 @@ def set_HEAD(oid):
         f.write(oid)
 
 
+def get_HEAD():
+    if Path.is_file(f"{GIT_DIR}/HEAD"):
+        with open(f"{GIT_DIR}/HEAD") as f:
+            return f.read().strip()
+
+
 def hash_object(data, type_="blob"):
     obj = type_.encode() + b"\x00" + data
     oid = hashlib.sha1(obj).hexdigest()