Normalize gitdir include patterns on Windows

Author: codex

git/config.py

@@ -576,9 +576,11 @@ def _all_items(section: str) -> List[Tuple[str, str]]:
             value = match.group(2).strip()
 
             if keyword in ["gitdir", "gitdir/i"]:
-                value = osp.expanduser(value)
+                value = osp.expanduser(value).replace("\\", "/")
+                git_dir = os.fspath(self._repo.git_dir).replace("\\", "/") if self._repo.git_dir else None
 
-                if not any(value.startswith(s) for s in ["./", "/"]):
+                drive, _tail = osp.splitdrive(value)
+                if not drive and not any(value.startswith(s) for s in ["./", "/"]):
                     value = "**/" + value
                 if value.endswith("/"):
                     value += "**"
@@ -590,9 +592,8 @@ def _all_items(section: str) -> List[Tuple[str, str]]:
                         lambda m: f"[{m.group().lower()!r}{m.group().upper()!r}]",
                         value,
                     )
-                if self._repo.git_dir:
-                    if fnmatch.fnmatchcase(os.fspath(self._repo.git_dir), value):
-                        paths += _all_items(section)
+                if git_dir and fnmatch.fnmatchcase(git_dir, value):
+                    paths += _all_items(section)
 
             elif keyword == "onbranch":
                 try:

test/test_config.py

@@ -7,7 +7,6 @@
 import io
 import os
 import os.path as osp
-import sys
 from unittest import mock
 
 import pytest
@@ -411,11 +410,6 @@ def test_multiple_include_paths_with_same_key(self, rw_dir):
             assert cr.get_value("user", "name") == "from-inc1"
             assert cr.get_value("core", "bar") == "from-inc2"
 
-    @pytest.mark.xfail(
-        sys.platform == "win32",
-        reason='Second config._has_includes() assertion fails (for "config is included if path is matching git_dir")',
-        raises=AssertionError,
-    )
     @with_rw_directory
     def test_conditional_includes_from_git_dir(self, rw_dir):
         # Initiate repository path.
@@ -443,6 +437,14 @@ def test_conditional_includes_from_git_dir(self, rw_dir):
             assert config._has_includes()
             assert config._included_paths() == [("path", path2)]
 
+        # Ensure that Git's forward-slash syntax matches native Windows paths.
+        with open(path1, "w") as stream:
+            stream.write(template.format("gitdir", git_dir.replace("\\", "/"), path2))
+
+        with GitConfigParser(path1, repo=repo) as config:
+            assert config._has_includes()
+            assert config._included_paths() == [("path", path2)]
+
         # Ensure that config is ignored if case is incorrect.
         with open(path1, "w") as stream:
             stream.write(template.format("gitdir", git_dir.upper(), path2))