Process filter error in copy-file and error handling

[Lennart Borgman (gmail)]

I got an error in copy-file because a remote directory did not exist. 
Emacs then (a bit to my surprise) continued with the next statement 
after copy-file. However if I turn on debug-on-error I get a backtrace 
(as expected).

Am I supposed to do something special in my code to stop executing after 
the error? Or is it a bug?

Here is (a simplified version of) my code:

  (defun my-upload-file(filename)
    (copy-file local-file
              (html-site-current-local-to-remote filename nil)
               0)
    (message "Upload ready"))

and here is what I get in the message buffer:

  Doing CD... [12 times]
  Copying myimg.jpg to /ftp:address@hidden:/htdocs/img/... [2 times]
  error in process filter: ange-ftp-cf2: Opening output file: FTP 
Error: "550 /htdocs/img/myimg.jpg: No such file or directory", 
/ftp:address@hidden:/htdocs/img/myimg.jpg
  error in process filter: Opening output file: FTP Error: "550 
/htdocs/img/myimg.jpg: No such file or directory", 
/ftp:address@hidden:/htdocs/img/myimg.jpg
  Upload ready