Write-tree delete all before read

ugit/base.py

@@ -1,4 +1,5 @@
 from pathlib import Path, PurePath
+import os
 
 from . import data
 
@@ -48,7 +49,27 @@ def get_tree(oid, base_path=""):
     return result
 
 
+def _empty_current_directory():
+    for root, dirnames, filenames in os.walk(".", topdown=False):
+        for filename in filenames:
+            path = PurePath.relative_to(f"{root}/{filename}")
+            if is_ignored(path) or not Path.is_file(path):
+                continue
+            Path.unlink(path)
+        for dirname in dirnames:
+            path = PurePath.relative_to(f"{root}/{dirname}")
+            if is_ignored(path):
+                continue
+            try:
+                Path.rmdir(path)
+            except (FileNotFoundError, OSError):
+                # Deletion might fail if the directory contains ignored files,
+                # so it's OK
+                pass
+
+
 def read_tree(tree_oid):
+    _empty_current_directory()
     for path, oid in get_tree(tree_oid, base_path="./").items():
         Path.mkdir(PurePath.parent(path), exist_ok=True)
         with open(path, "wb") as f: