Allow relative directory path when follow_symlinks=True (#2896)

* Fix for StaticFiles(follow_symlinks=True, directory="some relative path") that stopped working with commit eee4cdc

* Change test name

* Delete test parameter

---------

Co-authored-by: Bruno D. Rodrigues <bruno.rodrigues@bitsighttech.com>
Co-authored-by: Marcelo Trylesinski <marcelotryle@gmail.com>

Author: 3 people

starlette/staticfiles.py

@@ -153,6 +153,7 @@ def lookup_path(self, path: str) -> tuple[str, os.stat_result | None]:
             joined_path = os.path.join(directory, path)
             if self.follow_symlink:
                 full_path = os.path.abspath(joined_path)
+                directory = os.path.abspath(directory)
             else:
                 full_path = os.path.realpath(joined_path)
                 directory = os.path.realpath(directory)

tests/test_staticfiles.py

@@ -593,3 +593,11 @@ def test_staticfiles_self_symlinks(tmp_path: Path, test_client_factory: TestClie
     assert response.url == "http://testserver/index.html"
     assert response.status_code == 200
     assert response.text == "<h1>Hello</h1>"
+
+
+def test_staticfiles_relative_directory_symlinks(test_client_factory: TestClientFactory) -> None:
+    app = StaticFiles(directory="tests/statics", follow_symlink=True)
+    client = test_client_factory(app)
+    response = client.get("/example.txt")
+    assert response.status_code == 200
+    assert response.text == "123\n"