Looks good to me - I've seen this issue particularly with "Any Hostname" or the multisite "Domain Mapping" plugins. I think this will help resolve it - I will merge now. Thanks!

You could enforce safely the presence of a slash in self::upload_dir by using the trailingslashit function.

Just for the sake of avoiding a possible double slash issue (if self::upload_dir ends with a slash).

👍 otherwise, and thanks @fabrizim for dealing with it :-)

This lead to #71 where it seems to break things.

What is the initial reason of this PR?

Thanks.

I think I was mistaken when I committed this PR. The issue I thought it was resolving is related to this piece of code, but it is actually a problem with the Domain Mapping plugin for multisite installations, and this code would not fix that regardless.

Apologies for not being more careful when committing. I think we should revert this change unless we hear from @villeristi explaining the initial reason for the PR.

@fabrizim no worries. I honestly would not have thought it would be an issue just by looking at the code.