https://bugzilla.redhat.com/show_bug.cgi?id=2177855
--- Comment #12 from Petr Pisar ppisar@redhat.com --- I see. The server sends a preferred file name with "Content-Disposition: attachment; filename="libXISF-v0.2.0.tar.gz"; filename*=UTF-8''libXISF-v0.2.0.tar.gz" HTTP header. It's up to an HTTP client whether it will do the rename or not. E.g. wget, I used for examining the URL, does not do that (by default). "spectool -g libXISF.spec", a tool native to RPM, also does not do that. rpmbuild does not download any sources. I cannot see a problem. However, if you use an HTTP client which does the rename, you can instruct rpmbuild and spectool to rename with:
Source0: %{url}/archive/v%{version}.tar.gz#/%{name}-v%{version}.tar.gz
That should align rpmbuild with a downloader of your choice.