Fix rmtree for readonly directories

pre_commit/util.py

@@ -158,13 +158,14 @@ def cmd_output(*cmd, **kwargs):
 
 def rmtree(path):
     """On windows, rmtree fails for readonly dirs."""
-    def handle_remove_readonly(func, path, exc):  # pragma: no cover (windows)
+    def handle_remove_readonly(func, path, exc):
         excvalue = exc[1]
         if (
                 func in (os.rmdir, os.remove, os.unlink) and
                 excvalue.errno == errno.EACCES
         ):
-            os.chmod(path, stat.S_IRWXU | stat.S_IRWXG | stat.S_IRWXO)
+            for p in (path, os.path.dirname(path)):
+                os.chmod(p, os.stat(p).st_mode | stat.S_IWUSR)
             func(path)
         else:
             raise

tests/util_test.py

@@ -1,6 +1,7 @@
 from __future__ import unicode_literals
 
 import os.path
+import stat
 
 import pytest
 
@@ -8,6 +9,7 @@ from pre_commit.util import CalledProcessError
 from pre_commit.util import clean_path_on_failure
 from pre_commit.util import cmd_output
 from pre_commit.util import parse_version
+from pre_commit.util import rmtree
 from pre_commit.util import tmpdir
 
 
@@ -90,3 +92,14 @@ def test_parse_version():
     assert parse_version('0.0') == parse_version('0.0')
     assert parse_version('0.1') > parse_version('0.0')
     assert parse_version('2.1') >= parse_version('2')
+
+
+def test_rmtree_read_only_directories(tmpdir):
+    """Simulates the go module tree.  See #1042"""
+    tmpdir.join('x/y/z').ensure_dir().join('a').ensure()
+    mode = os.stat(str(tmpdir.join('x'))).st_mode
+    mode_no_w = mode & ~(stat.S_IWUSR | stat.S_IWGRP | stat.S_IWOTH)
+    tmpdir.join('x/y/z').chmod(mode_no_w)
+    tmpdir.join('x/y/z').chmod(mode_no_w)
+    tmpdir.join('x/y/z').chmod(mode_no_w)
+    rmtree(str(tmpdir.join('x')))