Interoperability with backslash (\) in key name

[cyberduck]

1527de5 created the issue

S3 keys that contain a backslash () are not displayed in the bucket at all.
Other files in the same bucket, which don't have a backslash in their key, are displayed correctly.

It's worth noting that Windows files are not allowed to have backslashes in their names - could this be the cause of the issue?

In comparison, CloudBerry Explorer for Amazon S3 lists such files, but fails to download them (I opened a ticket over there too).