PathPrefix is ignored

[SamMousa]

It seems this adapter fully ignores a configured path prefix.

[frankdejonge]

Correct, I saw it last week. I've got it on my list for Friday. If you need it sooner a PR is welcome (with tests).

[SamMousa]

Side note, the option is not really documented. Is path prefix supposed to be a guarantee from a security perspective?

[frankdejonge]

The path prefix is to facilitate scoping, which is not provided now but will be when implemented. Path traversal prevention is done at a different level, the path passed to the Filesystem instance is checked for this.

[SamMousa]

Alternative fix would be to have another look at my old PR for a decorator: thephpleague/flysystem#799.

The approach of a decorator is cleaner, more secure and will work for any adapter not the ones that happen to implement it.