Do not set winerror or filenames if they are None.

Author: ionelmc

.pre-commit-config.yaml

@@ -22,5 +22,5 @@ repos:
       - id: trailing-whitespace
       - id: end-of-file-fixer
       - id: mixed-line-ending
-        args: [--fix=lf]
+        args: [--fix]
       - id: debug-statements

src/tblib/pickling_support.py

@@ -65,13 +65,13 @@ def pickle_exception(
             'args': obj.args,
         }
         if isinstance(obj, OSError):
-            attrs.update(
-                errno=obj.errno,
-                strerror=obj.strerror,
-                winerror=getattr(obj, 'winerror', None),
-                filename=obj.filename,
-                filename2=obj.filename2,
-            )
+            attrs.update(errno=obj.errno, strerror=obj.strerror)
+            if (winerror := getattr(obj, 'winerror', None)) is not None:
+                attrs['winerror'] = winerror
+            if obj.filename is not None:
+                attrs['filename'] = obj.filename
+            if obj.filename2 is not None:
+                attrs['filename2'] = obj.filename2
 
         return (
             unpickle_exception_with_attrs,

tests/test_pickle_exception.py

@@ -1,3 +1,4 @@
+import traceback
 from traceback import format_exception
 
 try:
@@ -230,6 +231,35 @@ def test_oserror():
     assert exc.__traceback__ is not None
 
 
+class OpenError(Exception):
+    pass
+
+
+def bad_open():
+    try:
+        raise PermissionError(13, 'Booboo', 'filename', None, None)
+    except Exception as e:
+        raise OpenError(e) from e
+
+
+def test_permissionerror():
+    try:
+        bad_open()
+    except Exception as e:
+        exc = e
+
+    tblib.pickling_support.install(exc)
+    exc = pickle.loads(pickle.dumps(exc))
+    print(''.join(traceback.format_exception(exc)))
+    assert isinstance(exc, OpenError)
+    assert exc.__traceback__ is not None
+    assert repr(exc) == "OpenError(PermissionError(13, 'Booboo'))"
+    assert str(exc) == "[Errno 13] Booboo: 'filename'"
+    assert exc.errno == 13
+    assert exc.strerror == 'Permission denied'
+    assert exc.filename == 'filename'
+
+
 class BadError(Exception):
     def __init__(self):
         super().__init__('Bad Bad Bad!')