fix 1631 and add test (#1641)

diff --git a/CHANGES.md b/CHANGES.md
index 7352b8570757860b7bffaac1ee566ed6c6e769a4..1c53604d4d5bd0ce234f60e13ddfb6b5fbbdb4ab 100644 (file)
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -7,6 +7,8 @@
 - `Black` now respects `--skip-string-normalization` when normalizing multiline
   docstring quotes (#1637)
 
+- fixed a crash when PWD=/ on POSIX (#1631)
+
 ### 20.8b1
 
 #### _Packaging_

diff --git a/src/black/__init__.py b/src/black/__init__.py
index 34d8145c0f7aa703b3097569d63978898b0ee6b1..048e771ce961304eefe6b4b882beb8b02830e0da 100644 (file)
--- a/src/black/__init__.py
+++ b/src/black/__init__.py
@@ -5831,7 +5831,8 @@ def normalize_path_maybe_ignore(
     `report` is where "path ignored" output goes.
     """
     try:
-        normalized_path = path.resolve().relative_to(root).as_posix()
+        abspath = path if path.is_absolute() else Path.cwd() / path
+        normalized_path = abspath.resolve().relative_to(root).as_posix()
     except OSError as e:
         report.path_ignored(path, f"cannot be read because {e}")
         return None

diff --git a/tests/test_black.py b/tests/test_black.py
index 629afc5b0ad2c86fc340f4921bd5f24b3ba112da..bc80c8fca8b20c8f67b4384d722be1a84764b762 100644 (file)
--- a/tests/test_black.py
+++ b/tests/test_black.py
@@ -9,6 +9,7 @@ import inspect
 from io import BytesIO, TextIOWrapper
 import os
 from pathlib import Path
+from platform import system
 import regex as re
 import sys
 from tempfile import TemporaryDirectory
@@ -1939,6 +1940,23 @@ class BlackTestCase(unittest.TestCase):
             self.assertEqual(black.find_project_root((src_dir,)), src_dir.resolve())
             self.assertEqual(black.find_project_root((src_python,)), src_dir.resolve())
 
+    def test_bpo_33660_workaround(self) -> None:
+        if system() == "Windows":
+            return
+
+        # https://bugs.python.org/issue33660
+
+        old_cwd = Path.cwd()
+        try:
+            root = Path("/")
+            os.chdir(str(root))
+            path = Path("workspace") / "project"
+            report = black.Report(verbose=True)
+            normalized_path = black.normalize_path_maybe_ignore(path, root, report)
+            self.assertEqual(normalized_path, "workspace/project")
+        finally:
+            os.chdir(str(old_cwd))
+
 
 class BlackDTestCase(AioHTTPTestCase):
     async def get_application(self) -> web.Application: