core: utils: _copy_using: Put the dest dir name into the ignore pattern

Our default copy destination for the working copies of input
repositories is '.' which means that even the destination directory
(a temporary one) is copied recursively - luckily, the copy backend
seems to be smart enough not to get stuck in an infinite recursion.

Nevertheless, fix the issue by putting the destination dir name into
the ignore pattern of 'shutil.copytree'. This is fine because the
destination name is always going to be unique in our case and hence
there is close to 0% chance of a name collision preventing copying of
some relevant data (in case we don't copy to '.' by default anymore).

Fixes: 2937416

Signed-off-by: Erik Skultety <[email protected]>

cachi2/core/utils.py

@@ -91,7 +91,12 @@ def copy_directory(origin: Path, destination: Path) -> Path:
 
     def _copy_using(copy_function: Callable) -> None:
         shutil.copytree(
-            origin, destination, copy_function=copy_function, dirs_exist_ok=True, symlinks=True
+            origin,
+            destination,
+            copy_function=copy_function,
+            dirs_exist_ok=True,
+            symlinks=True,
+            ignore=shutil.ignore_patterns(destination.name),
         )
 
     if reflink.supported_at(origin):

tests/unit/test_utils.py

@@ -105,9 +105,7 @@ def test_copy_directory(
     else:
         copy_function = shutil.copy2
 
-    mock_shutil_copytree.assert_called_with(
-        origin, destination, copy_function=copy_function, dirs_exist_ok=True, symlinks=True
-    )
+    assert mock_shutil_copytree.call_args.kwargs["copy_function"] == copy_function
 
 
 @mock.patch("shutil.copy2")