Revert "Expand to long paths when resolving collection arguments"

This reverts commit 2e8f957.

Author: nicoddemus

src/_pytest/compat.py

@@ -1,5 +1,5 @@
 # mypy: allow-untyped-defs
-"""Python version and platform compatibility code."""
+"""Python version compatibility code."""
 from __future__ import annotations
 
 import dataclasses
@@ -301,39 +301,6 @@ def get_user_id() -> int | None:
         return uid if uid != ERROR else None
 
 
-if sys.platform == "win32":
-    from ctypes import create_unicode_buffer
-    from ctypes import windll
-
-    def ensure_long_path(p: Path) -> Path:
-        """
-        Returns the given path in its long form in Windows.
-
-        Short-paths follow the DOS restriction of 8 characters + 3 chars for file extension,
-        and are still supported by Windows.
-        """
-        # If the path does not exist, we cannot discover its long path.
-        if not p.exists():
-            return p
-        short_path = os.fspath(p)
-        # Use a buffer twice the size of the original path size to (reasonably) ensure we will be able
-        # to hold the long path.
-        buffer_size = len(short_path) * 2
-        buffer = create_unicode_buffer(buffer_size)
-        windll.kernel32.GetLongPathNameW(short_path, buffer, buffer_size)
-        long_path_str = buffer.value
-        # If we could not convert it, probably better to hard-crash this now rather
-        # than later.
-        assert long_path_str, f"Failed to convert short path to long path form:\n(size: {len(short_path)}):{short_path}"
-        return Path(buffer.value)
-
-else:
-
-    def ensure_long_path(p: Path) -> Path:
-        """No-op in other platforms."""
-        return p
-
-
 # Perform exhaustiveness checking.
 #
 # Consider this example:

src/_pytest/main.py

@@ -28,7 +28,6 @@
 
 from _pytest import nodes
 import _pytest._code
-from _pytest.compat import ensure_long_path
 from _pytest.config import Config
 from _pytest.config import directory_arg
 from _pytest.config import ExitCode
@@ -902,6 +901,10 @@ def collect(self) -> Iterator[Union[nodes.Item, nodes.Collector]]:
                     # Path part e.g. `/a/b/` in `/a/b/test_file.py::TestIt::test_it`.
                     if isinstance(matchparts[0], Path):
                         is_match = node.path == matchparts[0]
+                        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])
                     # Name part e.g. `TestIt` in `/a/b/test_file.py::TestIt::test_it`.
                     else:
                         # TODO: Remove parametrized workaround once collection structure contains
@@ -1009,6 +1012,4 @@ def resolve_collection_argument(
             else "directory argument cannot contain :: selection parts: {arg}"
         )
         raise UsageError(msg.format(arg=arg))
-    # Ensure we expand short paths to long paths on Windows (#11895).
-    fspath = ensure_long_path(fspath)
     return fspath, parts

testing/test_collection.py

@@ -9,7 +9,6 @@
 from typing import List
 
 from _pytest.assertion.util import running_on_ci
-from _pytest.compat import ensure_long_path
 from _pytest.config import ExitCode
 from _pytest.fixtures import FixtureRequest
 from _pytest.main import _in_venv
@@ -1764,43 +1763,27 @@ def test_foo(): assert True
     assert result.parseoutcomes() == {"passed": 1}
 
 
-class TestCollectionShortPaths:
-    @pytest.fixture
-    def short_path(self) -> Path:
-        short_path = tempfile.mkdtemp()
-        if "~" not in short_path:  # pragma: no cover
-            if running_on_ci():
-                # On CI, we are expecting that under the current GitHub actions configuration,
-                # tempfile.mkdtemp() is producing short paths, so we want to fail to prevent
-                # this from silently changing without us noticing.
-                pytest.fail(
-                    f"tempfile.mkdtemp() failed to produce a short path on CI: {short_path}"
-                )
-            else:
-                # We want to skip failing this test locally in this situation because
-                # depending on the local configuration tempfile.mkdtemp() might not produce a short path:
-                # For example, user might have configured %TEMP% exactly to avoid generating short paths.
-                pytest.skip(
-                    f"tempfile.mkdtemp() failed to produce a short path: {short_path}, skipping"
-                )
-        return Path(short_path)
-
-    @pytest.mark.skipif(not sys.platform.startswith("win"), reason="Windows only")
-    def test_ensure_long_path_win(self, short_path: Path) -> None:
-        long_path = ensure_long_path(short_path)
-        assert len(os.fspath(long_path)) > len(os.fspath(short_path))
-
-    @pytest.mark.skipif(not sys.platform.startswith("win"), reason="Windows only")
-    def test_collect_short_file_windows(
-        self, pytester: Pytester, short_path: Path
-    ) -> None:
-        """Reproducer for #11895: short paths not collected on Windows."""
-        test_file = short_path.joinpath("test_collect_short_file_windows.py")
-        test_file.write_text("def test(): pass", encoding="UTF-8")
-        result = pytester.runpytest(short_path)
-        assert result.parseoutcomes() == {"passed": 1}
-
-    def test_ensure_long_path_general(self, tmp_path: Path) -> None:
-        """Sanity check: a normal path to ensure_long_path works on all platforms."""
-        assert ensure_long_path(tmp_path) == tmp_path
-        assert ensure_long_path(tmp_path / "non-existent") == tmp_path / "non-existent"
+@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."""
+    short_path = tempfile.mkdtemp()
+    if "~" not in short_path:  # pragma: no cover
+        if running_on_ci():
+            # On CI, we are expecting that under the current GitHub actions configuration,
+            # tempfile.mkdtemp() is producing short paths, so we want to fail to prevent
+            # this from silently changing without us noticing.
+            pytest.fail(
+                f"tempfile.mkdtemp() failed to produce a short path on CI: {short_path}"
+            )
+        else:
+            # We want to skip failing this test locally in this situation because
+            # depending on the local configuration tempfile.mkdtemp() might not produce a short path:
+            # For example, user might have configured %TEMP% exactly to avoid generating short paths.
+            pytest.skip(
+                f"tempfile.mkdtemp() failed to produce a short path: {short_path}, skipping"
+            )
+
+    test_file = Path(short_path).joinpath("test_collect_short_file_windows.py")
+    test_file.write_text("def test(): pass", encoding="UTF-8")
+    result = pytester.runpytest(short_path)
+    assert result.parseoutcomes() == {"passed": 1}