bugfix: get dump folder contents in respective output folder (#4034)

The relative path for external git directory was computed relative to
the root of the repo itself, which created a relative path which is
current working directory. So, all of the contents of the erepo to download
was dumped in the pwd rather than inside of it's own directory.

Fix #4033

dvc/repo/tree.py

@@ -404,10 +404,8 @@ class RepoTree(BaseTree):
 
         for root, _, files in self.walk(top):
             root = PathInfo(root)
-            dest_dir = root.relative_to(top)
-            makedirs(dest_dir, exist_ok=True)
+            makedirs(dest, exist_ok=True)
             for fname in files:
                 src = root / fname
-                dest = dest_dir / fname
                 with self.open(src, mode="rb") as fobj:
-                    copy_fobj_to_file(fobj, dest)
+                    copy_fobj_to_file(fobj, dest / fname)

tests/func/test_get.py

@@ -33,7 +33,9 @@ def test_get_repo_dir(tmp_dir, erepo_dir):
     trees_equal(erepo_dir / "dir", "dir_imported")
 
 
-def test_get_git_file(tmp_dir, erepo_dir):
+@pytest.mark.parametrize("repo_type", ["git_dir", "erepo_dir"])
+def test_get_git_file(request, tmp_dir, repo_type):
+    erepo_dir = request.getfixturevalue(repo_type)
     src = "some_file"
     dst = "some_file_imported"
 
@@ -45,7 +47,9 @@ def test_get_git_file(tmp_dir, erepo_dir):
     assert (tmp_dir / dst).read_text() == "hello"
 
 
-def test_get_git_dir(tmp_dir, erepo_dir):
+@pytest.mark.parametrize("repo_type", ["git_dir", "erepo_dir"])
+def test_get_git_dir(request, tmp_dir, repo_type):
+    erepo_dir = request.getfixturevalue(repo_type)
     src = "some_directory"
     dst = "some_directory_imported"