percent-encoded characters in URLs are double-encoded

Problem/Motivation

• Create a redirect from: foo to: sites/default/files/foo%20bar.pdf.
• When the redirect is followed, it will be double-encoded as sites/default/files/foo%2520bar.pdf, leading to a 404 error.
• Entering a literal space produces the error "The redirect path sites/default/files/foo bar.pdf is not valid.".

There is a workaround for the To URL: by entering a full http:// URL, and substituting some uppercase letters in the domain name, you can trick the module into thinking it's an external URL, and it will not double-encode the percent characters.

The workaround for the From URL appears to be replace each %20 with a space.