Do not collect symlinked tests under Windows

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 created using :fixture:`tmp_path` have been collected multiple times in CI under Windows.

src/_pytest/main.py

@@ -924,7 +924,13 @@
                         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_foo(): assert True
 
 @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():
@@ -1789,6 +1789,26 @@ def test_collect_short_file_windows(pytester: Pytester) -> None:
     assert result.parseoutcomes() == {"passed": 1}
 
 
+def test_not_collect_symlink_syblings(
+    pytester: Pytester, tmp_path: Path, request: pytest.FixtureRequest
+) -> None:
+    """
+    Do not collect from directories that are symlinks to other directories in the same path.
+
+    The check for short paths under Windows via os.path.samefile, introduced in #11936, also finds the symlinked
+    directory created by tmp_path/tmpdir.
+
+    #12039
+    """
+    # Use tmp_path because it creates a symlink with the name "current" next to the directory it creates.
+    assert tmp_path.parent.joinpath(f"{request.node.name}current").is_symlink() is True
+
+    tmp_path.joinpath("test_foo.py").write_text("def test(): pass", encoding="UTF-8")
+
+    result = pytester.runpytest_subprocess(tmp_path, "-sv")
+    result.assert_outcomes(passed=1)
+
+
 def test_pyargs_collection_tree(pytester: Pytester, monkeypatch: MonkeyPatch) -> None:
     """When using `--pyargs`, the collection tree of a pyargs collection
     argument should only include parents in the import path, not up to confcutdir.
@@ -1832,3 +1852,12 @@ 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}