Add test_checkout_pygit2_with_home_env_unset unit test

tests/pytests/unit/utils/test_gitfs.py

@@ -7,6 +7,7 @@
 import salt.fileserver.gitfs
 import salt.utils.gitfs
 from salt.exceptions import FileserverConfigError
+from tests.support.helpers import patched_environ
 from tests.support.mock import MagicMock, patch
 
 try:
@@ -239,6 +240,20 @@ def test_checkout_pygit2(_prepare_provider):
     assert provider.checkout() is None
 
 
+@pytest.mark.skipif(not HAS_PYGIT2, reason="This host lacks proper pygit2 support")
+@pytest.mark.skip_on_windows(
+    reason="Skip Pygit2 on windows, due to pygit2 access error on windows"
+)
+def test_checkout_pygit2_with_home_env_unset(_prepare_provider):
+    provider = _prepare_provider
+    provider.remotecallbacks = None
+    provider.credentials = None
+    with patched_environ(__cleanup__=["HOME"]):
+        assert "HOME" not in os.environ
+        provider.init_remote()
+        assert "HOME" in os.environ
+
+
 @pytest.mark.skipif(not HAS_PYGIT2, reason="This host lacks proper pygit2 support")
 @pytest.mark.skip_on_windows(
     reason="Skip Pygit2 on windows, due to pygit2 access error on windows"