FTP unnecessary upload retries

[Sob]

When trying to upload file (by mistake) to directory where uploads are not permitted, TC tries it three times before failing even though server returns permanent failure reply (550 or 553 depending on server software). The retries (although useless) would not be a problem by themselves, it's those three seconds pauses between them. Even Cancel button does not work and TC is completely unusable for whole six seconds.

[ghisler(Author)]

TC does these retries because of the many complaints of aborted uploads - better one retry too much than one more aborted transfer. For example, there could be a target file which is currently locked which causes the error.

[Sob]

I'd expect temporary error to be returned (code 450) for locked files that would be otherwise writable. But it seems I'm wrong, because quick try with two different servers and locked files returned permanent 550 in both cases. It makes permanent and temporary errors indistinguishable. :(

I understand the reason for retries. I could argue against them, e.g. about likelihood of file becoming unlocked in six seconds and if it's really worth the waiting. But ok, there is some chance and if it sometimes saves the transfer of multiple files in queue, so be it.

But it's really annoying to wait whole six seconds to realize that I just tried to upload file somewhere without write permission and it never had any chance to succeed. What about compromise, skip retries for the first file?