diff --git a/aider/main.py b/aider/main.py
index a3bf80b1c..97efe8bd5 100644
--- a/aider/main.py
+++ b/aider/main.py
@@ -405,7 +405,7 @@ def main(argv=None, input=None, output=None, force_git_root=None):
         dry_run=args.dry_run,
     )
 
-    fnames = args.files
+    fnames = [str(Path(fn).resolve()) for fn in args.files]
     if len(args.files) > 1:
         good = True
         for fname in args.files:
@@ -422,11 +422,11 @@ def main(argv=None, input=None, output=None, force_git_root=None):
     if len(args.files) == 1:
         if Path(args.files[0]).is_dir():
             if args.git:
-                git_dname = args.files[0]
+                git_dname = str(Path(args.files[0]).resolve())
                 fnames = []
             else:
                 io.tool_error(f"{args.files[0]} is a directory, but --no-git selected.")
-                return -1
+                return 1
 
     # We can't know the git repo for sure until after parsing the args.
     # If we guessed wrong, reparse because that changes things like
@@ -506,7 +506,7 @@ def main(argv=None, input=None, output=None, force_git_root=None):
         )
     except ValueError as err:
         io.tool_error(str(err))
-        return
+        return 1
 
     if args.show_repo_map:
         repo_map = coder.get_repo_map()
diff --git a/tests/test_main.py b/tests/test_main.py
index 6bda03c7f..e23268c4c 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -44,6 +44,33 @@ class TestMain(TestCase):
         main(["--yes", "foo.txt"], input=DummyInput(), output=DummyOutput())
         self.assertTrue(os.path.exists("foo.txt"))
 
+    @patch("aider.repo.GitRepo.get_commit_message", return_value="mock commit message")
+    def test_main_with_empty_git_dir_new_files(self, _):
+        make_repo()
+        main(["--yes", "foo.txt", "bar.txt"], input=DummyInput(), output=DummyOutput())
+        self.assertTrue(os.path.exists("foo.txt"))
+        self.assertTrue(os.path.exists("bar.txt"))
+
+    def test_main_with_dname_and_fname(self):
+        subdir = Path("subdir")
+        subdir.mkdir()
+        make_repo(str(subdir))
+        res = main(["subdir", "foo.txt"], input=DummyInput(), output=DummyOutput())
+        self.assertNotEqual(res, None)
+
+    @patch("aider.repo.GitRepo.get_commit_message", return_value="mock commit message")
+    def test_main_with_subdir_repo_fnames(self, _):
+        subdir = Path("subdir")
+        subdir.mkdir()
+        make_repo(str(subdir))
+        main(
+            ["--yes", str(subdir / "foo.txt"), str(subdir / "bar.txt")],
+            input=DummyInput(),
+            output=DummyOutput(),
+        )
+        self.assertTrue((subdir / "foo.txt").exists())
+        self.assertTrue((subdir / "bar.txt").exists())
+
     def test_main_with_git_config_yml(self):
         make_repo()
 
diff --git a/tests/utils.py b/tests/utils.py
index 8ece2b4a4..32a2deaf5 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -42,7 +42,11 @@ class GitTemporaryDirectory(ChdirTemporaryDirectory):
         return res
 
 
-def make_repo():
-    repo = git.Repo.init()
+def make_repo(path=None):
+    if not path:
+        path = "."
+    repo = git.Repo.init(path)
     repo.config_writer().set_value("user", "name", "Test User").release()
     repo.config_writer().set_value("user", "email", "testuser@example.com").release()
+
+    return repo