KeepAliveDuringTransfer throws FtpException after 2 NOOP commands

Question

First off, I am currently using build 3.0.3428. I am testing against a local FileZilla FTP server throttled to 10 KB/s.

Before I renew my license I'm trying to determine whether or not this issue has been resolved in the newer releases.

I am trying to use FtpOptions.KeepAliveDuringTransfer to enable periodic NOOPs on the control stream to keep a connection open. This works fine for the first NOOP command but after the second one it throws an FtpException with an error message of "OK (200)".

I believe the issue is in the Rebex.Net.FtpDownloadStream.ProcessResponse method, specifically where it's checking for a base._response.Group != 1 the first time. If I'm understanding the way this works properly, the group is in fact 2 from the OK 200 response returned by the NOOP, but this is causing the code to throw an exception where I don't think it should.

Am I doing something wrong here or is this an actual bug that has been resolved in a newer version?

Answer 1

This particular NOOP response ("200 OK") was not properly understood on Rebex FTP 3.0.3428 (it has to distinguish NOOP responses from RETR/STOR responses, which is quite tricky).

This has been resolved in version 3.0.3793 - since this build, Rebex FTP supports this NOOP response as well and the exception should no longer occur.

Comments

Based on your response I just renewed my license and got the latest version and it does indeed appear to work properly now!

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Thanks for renewing, I'm glad it works fine now!