Fix rmtree to remove directories with read-only files

Fix pytest-dev#5524

changelog/5524.bugfix.rst

@@ -0,0 +1,2 @@
+Fix issue where ``tmp_path`` and ``tmpdir`` would not remove directories containing files marked as read-only,
+which could lead to pytest crashing when executed a second time with the ``--basetemp`` option.

src/_pytest/pathlib.py

@@ -38,13 +38,47 @@ def ensure_reset_dir(path):
 
 def rmtree(path, force=False):
     if force:
-        # NOTE: ignore_errors might leave dead folders around.
-        #       Python needs a rm -rf as a followup.
-        shutil.rmtree(str(path), ignore_errors=True)
+        rm_rf(path)
     else:
         shutil.rmtree(str(path))
 
 
+def rm_rf(path):
+    """Remove the path contents recursively, even if some elements
+    are read-only.
+    """
+
+    def chmod_w(p):
+        import stat
+
+        mode = os.stat(str(p)).st_mode
+        os.chmod(str(p), mode | stat.S_IWRITE)
+
+    def force_writable_and_retry(function, p, excinfo):
+        p = Path(p)
+
+        # for files, we need to recursively go upwards
+        # in the directories to ensure they all are also
+        # writable
+        if p.is_file():
+            for parent in p.parents:
+                chmod_w(parent)
+                # stop when we reach the original path passed to rm_rf
+                if parent == path:
+                    break
+
+        chmod_w(p)
+        try:
+            # retry the function that failed
+            function(p)
+        except Exception:
+            # need to silently ignore this error to preserve the 
+            # previous behavior of rmtree(..., force=True)
+            pass
+
+    shutil.rmtree(str(path), onerror=force_writable_and_retry)
+
+
 def find_prefixed(root, prefix):
     """finds all elements in root that begin with the prefix, case insensitive"""
     l_prefix = prefix.lower()

testing/test_tmpdir.py

@@ -1,3 +1,5 @@
+import os
+import stat
 import sys
 
 import attr
@@ -326,6 +328,37 @@ def test_rmtree(self, tmp_path):
         rmtree(adir, force=True)
         assert not adir.exists()
 
+    def test_rmtree_with_read_only_file(self, tmp_path):
+        """Ensure rmtree can remove directories with read-only files in them (#5524)"""
+        from _pytest.pathlib import rmtree
+
+        fn = tmp_path / "dir/foo.txt"
+        fn.parent.mkdir()
+
+        fn.touch()
+
+        mode = os.stat(str(fn)).st_mode
+        os.chmod(str(fn), mode & ~stat.S_IWRITE)
+
+        rmtree(fn.parent, force=True)
+
+        assert not fn.parent.is_dir()
+
+    def test_rmtree_with_read_only_directory(self, tmp_path):
+        """Ensure rmtree can remove read-only directories (#5524)"""
+        from _pytest.pathlib import rmtree
+
+        adir = tmp_path / "dir"
+        adir.mkdir()
+
+        (adir / "foo.txt").touch()
+        mode = os.stat(str(adir)).st_mode
+        os.chmod(str(adir), mode & ~stat.S_IWRITE)
+
+        rmtree(adir, force=True)
+
+        assert not adir.is_dir()
+
     def test_cleanup_ignores_symlink(self, tmp_path):
         the_symlink = tmp_path / (self.PREFIX + "current")
         attempt_symlink_to(the_symlink, tmp_path / (self.PREFIX + "5"))
@@ -349,3 +382,24 @@ def attempt_symlink_to(path, to_path):
 
 def test_tmpdir_equals_tmp_path(tmpdir, tmp_path):
     assert Path(tmpdir) == tmp_path
+
+
+def test_basetemp_with_read_only_files(testdir):
+    """Integration test for #5524"""
+    testdir.makepyfile(
+        """
+        import os
+        import stat
+
+        def test(tmp_path):
+            fn = tmp_path / 'foo.txt'
+            fn.write_text('hello')
+            mode = os.stat(str(fn)).st_mode
+            os.chmod(str(fn), mode & ~stat.S_IREAD)
+    """
+    )
+    result = testdir.runpytest("--basetemp=tmp")
+    assert result.ret == 0
+    # running a second time and ensure we don't crash
+    result = testdir.runpytest("--basetemp=tmp")
+    assert result.ret == 0