Disable merge_includes in config writers

git/repo/base.py

@@ -600,7 +600,7 @@ def config_writer(self, config_level: Lit_config_levels = "repository") -> GitCo
             system = system wide configuration file
             global = user level configuration file
             repository = configuration file for this repository only"""
-        return GitConfigParser(self._get_config_path(config_level), read_only=False, repo=self)
+        return GitConfigParser(self._get_config_path(config_level), read_only=False, repo=self, merge_includes=False)
 
     def commit(self, rev: Union[str, Commit_ish, None] = None) -> Commit:
         """The Commit object for the specified revision

test/test_refs.py

@@ -15,6 +15,7 @@
     SymbolicReference,
     GitCommandError,
     RefLog,
+    GitConfigParser,
 )
 from git.objects.tag import TagObject
 from test.lib import TestBase, with_rw_repo
@@ -172,6 +173,26 @@ def test_heads(self, rwrepo):
         assert log[0].oldhexsha == pcommit.NULL_HEX_SHA
         assert log[0].newhexsha == pcommit.hexsha
 
+    @with_rw_repo("HEAD", bare=False)
+    def test_set_tracking_branch_with_import(self, rwrepo):
+        # prepare included config file
+        included_config = osp.join(rwrepo.git_dir, "config.include")
+        with GitConfigParser(included_config, read_only=False) as writer:
+            writer.set_value("test", "value", "test")
+        assert osp.exists(included_config)
+
+        with rwrepo.config_writer() as writer:
+            writer.set_value("include", "path", included_config)
+
+        for head in rwrepo.heads:
+            head.set_tracking_branch(None)
+            assert head.tracking_branch() is None
+            remote_ref = rwrepo.remotes[0].refs[0]
+            assert head.set_tracking_branch(remote_ref) is head
+            assert head.tracking_branch() == remote_ref
+            head.set_tracking_branch(None)
+            assert head.tracking_branch() is None
+
     def test_refs(self):
         types_found = set()
         for ref in self.rorepo.refs: