SFTP: approving server's public key fails

[pmattern]

PCManFM fails to approve public host keys of SSH servers that haven't been contacted before.

When connection attempts are made, there's first a dialogue box "pcmanfm-qt" which explains that the remote server isn't known and presents the public key's fingerprint. After clicking "Log In Anyway" there's a second box "Error" explaining that login failed.
Same findings if ~/.ssh/known_hosts lacks or if it exists but lacks the server in question's public key.
Once the key was accepted, e. g. by running an SSH session from the shell, SFTP connections work within PCManFM, too.

FWIW problem can't be seen with Thunar on the very same system.

Seen on Arch Linux x86_64 running latest git version of all LXQt components compiled against Qt5.

[pmattern]

A part of a feature isn't working which impairs the feature as a whole.
This is a bug.
I'm not saying it's high drama or something. And personally I don't even care too much as I know how to work around. Yet it's a bug.

[jylenhof-auchan]

Confirming this bug

[tsujan]

Please don't change the label again! Controlling SFTP, SMB, etc. could be a feature; its lack isn't a bug.

PRs will be accepted.

[fulalas]

In pcmanfm-qt 0.12.0 this works (I've just confirmed). So it's a regression, not a new feature.

pcmanfm-qt.mp4

Hope this can help :)