Do not collect symlinked tests under Windows

The check for short paths under Windows via os.path.samefile, introduced in #11936, also found similar tests in symlinked tests in the GH Actions CI.
This checks additionally that one of the files is not a symlink.

Fixes #12039.

AUTHORS

@@ -283,6 +283,7 @@ Mike Hoyle (hoylemd)
 Mike Lundy
 Milan Lesnek
 Miro Hrončok
+mrbean-bremen
 Nathaniel Compton
 Nathaniel Waisbrot
 Ned Batchelder

changelog/12039.bugfix.rst

@@ -0,0 +1 @@
+Fixed a regression in 8.0.2 where tests have been collected multiple times in the CI under Windows

src/_pytest/main.py

@@ -924,7 +924,14 @@ class Session(nodes.Collector):
                         if sys.platform == "win32" and not is_match:
                             # In case the file paths do not match, fallback to samefile() to
                             # account for short-paths on Windows (#11895).
-                            is_match = os.path.samefile(node.path, matchparts[0])
+                            same_file = os.path.samefile(node.path, matchparts[0])
+                            # we don't want to find links, so we at least
+                            # exclude symlinks to regular directories
+                            is_match = (
+                                    same_file and
+                                    os.path.islink(node.path) == os.path.islink(matchparts[0])
+                            )
+
                     # Name part e.g. `TestIt` in `/a/b/test_file.py::TestIt::test_it`.
                     else:
                         # TODO: Remove parametrized workaround once collection structure contains

testing/test_collection.py

@@ -1765,7 +1765,7 @@ def test_does_not_crash_on_recursive_symlink(pytester: Pytester) -> None:
 
 @pytest.mark.skipif(not sys.platform.startswith("win"), reason="Windows only")
 def test_collect_short_file_windows(pytester: Pytester) -> None:
-    """Reproducer for #11895: short paths not colleced on Windows."""
+    """Reproducer for #11895: short paths not collected on Windows."""
     short_path = tempfile.mkdtemp()
     if "~" not in short_path:  # pragma: no cover
         if running_on_ci():
@@ -1832,3 +1832,12 @@ def test_pyargs_collection_tree(pytester: Pytester, monkeypatch: MonkeyPatch) ->
         ],
         consecutive=True,
     )
+
+
+def test_collect_symlinks(pytester: Pytester, tmpdir) -> None:
+    """Regression test for #12039: Tests collected multiple times under Windows."""
+    test_file = Path(tmpdir) / "symlink_collection_test.py"
+    test_file.write_text("def test(): pass", encoding="UTF-8")
+    result = pytester.runpytest(tmpdir)
+    # this failed in CI only (GitHub actions)
+    assert result.parseoutcomes() == {"passed": 1}