Fix SymbolicReference reference typing

Author: Yobmod

git/refs/head.py

@@ -142,7 +142,7 @@ def delete(cls, repo: 'Repo', *heads: 'Head', **kwargs: Any):
             flag = "-D"
         repo.git.branch(flag, *heads)
 
-    def set_tracking_branch(self, remote_reference: 'RemoteReference') -> 'Head':
+    def set_tracking_branch(self, remote_reference: Union['RemoteReference', None]) -> 'Head':
         """
         Configure this branch to track the given remote reference. This will alter
             this branch's configuration accordingly.

git/refs/symbolic.py

@@ -28,6 +28,7 @@
 
 if TYPE_CHECKING:
     from git.repo import Repo
+    from git.refs import Reference
 
 T_References = TypeVar('T_References', bound='SymbolicReference')
 
@@ -356,8 +357,9 @@ def set_reference(self, ref, logmsg=None):
         return self
 
     # aliased reference
-    reference = property(_get_reference, set_reference, doc="Returns the Reference we point to")
-    ref: Union[Commit_ish] = reference     # type: ignore  # Union[str, Commit_ish, SymbolicReference]
+    reference: Union[Commit_ish, 'Reference'] = property(                 # type: ignore
+        _get_reference, set_reference, doc="Returns the Reference we point to")
+    ref = reference
 
     def is_valid(self):
         """

git/repo/base.py

@@ -422,7 +422,7 @@ def _to_full_tag_path(path):
 
     def create_head(self, path: PathLike, commit: str = 'HEAD',
                     force: bool = False, logmsg: Optional[str] = None
-                    ) -> 'SymbolicReference':
+                    ) -> 'Head':
         """Create a new head within the repository.
         For more documentation, please see the Head.create method.
 
@@ -788,9 +788,8 @@ def ignored(self, *paths: PathLike) -> List[PathLike]:
         return proc.replace("\\\\", "\\").replace('"', "").split("\n")
 
     @property
-    def active_branch(self) -> 'SymbolicReference':
+    def active_branch(self) -> 'HEAD':
         """The name of the currently active branch.
-
         :return: Head to the active branch"""
         return self.head.reference
 

test/test_refs.py

@@ -4,6 +4,7 @@
 # This module is part of GitPython and is released under
 # the BSD License: http://www.opensource.org/licenses/bsd-license.php
 
+from git.repo.base import Repo
 from itertools import chain
 
 from git import (
@@ -125,11 +126,15 @@ def test_heads(self, rwrepo):
             gp_tracking_branch = rwrepo.create_head('gp_tracking#123')
             special_name_remote_ref = rwrepo.remotes[0].refs[special_name]  # get correct type
             gp_tracking_branch.set_tracking_branch(special_name_remote_ref)
-            assert gp_tracking_branch.tracking_branch().path == special_name_remote_ref.path
+            TBranch = gp_tracking_branch.tracking_branch()
+            if TBranch is not None:
+                assert TBranch.path == special_name_remote_ref.path
 
             git_tracking_branch = rwrepo.create_head('git_tracking#123')
             rwrepo.git.branch('-u', special_name_remote_ref.name, git_tracking_branch.name)
-            assert git_tracking_branch.tracking_branch().name == special_name_remote_ref.name
+            TBranch = gp_tracking_branch.tracking_branch()
+            if TBranch is not None:
+                assert TBranch.name == special_name_remote_ref.name
         # END for each head
 
         # verify REFLOG gets altered