Identifier split into two when using ignore=W503

[mattearllongshot]

See below. Notice that abcd becomes a bcd in the modified version. It seems sensitive to various things, eg. length of the identifier, line breaks.

Python Code

~/junk/autopep8_bug.py

if (
        X or
        abcd/Y
):
    pass

Command Line and Configuration

~/junk/pycodestyle.repro

[pycodestyle]
ignore = W503

Command Line

$ autopep8 --global-config ~/junk/pycodestyle.repro --diff ~/junk/autopep8_bug.py 
--- original//home/matthew/junk/autopep8_bug.py
+++ fixed//home/matthew/junk/autopep8_bug.py
@@ -1,6 +1,5 @@
 if (
-        X or
-        abcd/Y
+        X
+        or a bcd / Y
 ):
     pass

Your Environment

• Python version: Python 3.8.1
• autopep8 version: autopep8 1.5.7 (pycodestyle: 2.7.0)
• Platform: Ubuntu 18.04.1 LTS