checkHost returns FAILURE instead of MISMATCH, MATCH or NOTFOUND

[dmp1ce]

I noticed that withSSH2User doesn't error when known_hosts doesn't have the hosts key. I tested in GHCi and checkHost returned FAILURE instead of NOTFOUND or MATCH. I tested with a host which is in known_hosts and a host which was not in known_hosts. I would expect checkHost to return NOTFOUND and MATCH instead of FAILURE for the two cases.

I am running Arch Linux and version 1.8.2 of libssh2 and version 0.2.0.7 of libssh2-hs library.

Is the intention for withSSH2User to only fail if MISMATCH is found? I would also expect NOTFOUND to cause an error too.

[portnov]

As far as I see, there are actually two questions.

1. Why does checkKnownHost return FAILURE and not NOTFOUND in this case? This I do not know; checkKnownHost is a trivial wrapper around libssh2's function; I assume this is expected behaivour of that function. You can consult libssh2 documentation.
2. Why does withSSH2User (and other withSSH2* functions) check for MISMATCH only and not for other types of errors? It seems that I've seen only this type of errors while testing bindings, so I've checked only for it. I can add check for NOTFOUND and FAILURE easily. I hope noone will say this is unexpected behaivour...

[dmp1ce]

I don't think FAILURE is the expected behavior. I think FAILURE is returned when something has gone wrong. I've looked at the documentation but I'll need to do more testing to determine how to get the other results. https://www.libssh2.org/libssh2_knownhost_check.html