I think the related issues were MNG-6209, MNG-6275
Stephen wrote a small integration test to show which extensions were visible to who and in which order.
It showed there are some edge cases that didn't work as expected.
However, I can't find that project anymore.
I hope Stephen still has a link.
I am really confused right now. One ticket says (MNG-4381) that Maven
2.x did not provide extensions to be visible to plugins yet MNG-2749
says the opposite. Moreover, MNG-3281 says that this is to be restored.
Looking at the provided snippet, this works as long as the extensions is
a single artifact w/o a dependency tree which is actually a hack for
backwards-compat to Maven 2.x.
So please tell me, since Wagon FTP is more than one artifact, how can
this be available to plugins?