(If Krusader is installed, change krarc to sevenz in the URL bar if necessary.)
Test using Dolphin:
Enable "Open archives as folder" in Dolphin, then open and browse a 7z archive using the sevenz protocol.
Test using Gwenview:
View a 7z archive containing photos. Browse and view images inside the archive.
There is a weird bug if I name the protocol as "7z" or "7zip":
- If I double click on the 7z file, Dolphin gives the "invalid protocol" error.
- If I try to manually enter the URL in Dolphin, i.e. 7z:/tmp/bar.7z or 7zip:/tmp/bar.7z, it does not work too - it is somehow being treated as a host (hostname) instead of a protocol.
I suspect that a KIO protocol should not have a name that starts with a number, otherwise there will be bugs.