If the upload fails, you should still have the content in the editor, so you can reupload it once you free the disk.
Using WinSCP 3.7.6 (B 306)
If the disk quota has been exhausted on the server and you go to edit a file
you'll get the following error and the original file on the server GETS DELETED.
"Copying files to remote side failed"
General failure (server should provide error description).
Error code: 4
Error message from server: Failure
Request code: 6
Does WinSCP delete the Original, then upload the newly modified file?
If so, this is flawded. It should upload the modified file with a temp name
and after a successful tranfer, delete the original and rename the temp.
Any thoughts?