[TC all versions] Background FTP download fails under certain circumstances.

[petermad]

Steps to reproduce:

1. In "Configuration" -> "Options..." -> "FTP" disable "Use passive mode by default".
2. In the "Connect to ftp server" dialog (Ctrl+F) configure a connection enabeling both "SSL/TLS" and "Use passive mode for transfers (like a WWW browser)".
3. Open the Connection and select a file
4. Open the Background Transfer Manager ("Commands" -> "Background Transfer Manager")
5. Click the [+] button in the BTM and choose "Add selected items for downloading".
6. Accept the suggested path an press OK
The BTM stalls - and it takes several clicks on the red x in the upper right corner to close the dialog. The has made a zero-byte copy of the file locally.

7. Close the FTP connection:
8. In "Configuration" -> "Options..." -> "FTP" enable "Use passive mode by default".
9. Perform step 3 - 6 again - the file is now downloaded without any problems.

10. Close the FTP connection:
11. Disable "Configuration" -> "Options..." -> "FTP" -> "Use passive mode by default" again.
12. In the "Connect to ftp server" dialog (Ctrl+F) disable "SSL/TLS" for the connection.
13. Perform step 3 - 6 again - the file is downloaded without any problems.

14. Close the FTP connection:
15. In the "Connect to ftp server" dialog (Ctrl+F) disable "Use passive mode for transfers (like a WWW browser)" for the connection..
16. Perform step 3 - 6 again - the file is downloaded without any problems.

So the problem only exists when "Configuration" -> "Options..." -> "FTP" .> "Use passive mode by default" is disabled - AND "SSL/TLS" and "Use passive mode for transfers (like a WWW browser)" are both enabled for the connection.

The problem occurs in both 32bit and 64bit TC.

It goes at least back to TC 9.22, but in the older versions of TC it is easier to close the stalled BTM dialog, than it is in the newer versions of TC where the option of "Finish copying the current file" when aborting the operation was introduced.

[ghisler(Author)]

When you add the files via + button, they aren't added as a part of the connection. Instead, they are added in the form
ftps://user@host/path/filename.ext
You can see this by clicking pause before adding them. This is the same as when using ftp download from list.
In this case, the default option for passive mode will be used, which would be active mode in your case.

If you want to use the options of the current connection, use F5 and then check the background option. However, this will open a new background transfer manager, because it has to open the connection at the start to pass the ftp options to it.

Currently I don't see any solution for this problem.

[petermad]

I see - the Background Transfer Manager use ftps: if that is chosen for the connection, and since my server can not use ftps: without also using passive mode the Background Transfer Manager fails.

I can use ftp: both with and without using passive mode though.

Maybe it should be added to the Help for "Use passive mode by default" that it might be necessary for SSL/TLS connections when using the Background Transfer Manager.

[petermad]

Note that this setting is used in the background transfer manager when adding ftps URLs, e.g. when using the "+" button during an active connection

.
The above is added to the Help for TC 11.02rc2

Moderator message from: petermad » 2023-10-11, 22:44 UTC

Moved to "TC fixed bugs" from "TC11.x bug reports (English)"