I am trying to use proxy to download a file from an ftp server. The
proxy is a http type ISA server using basic authentication. When I
provide the correct username and password for the proxy the correct file
is downloaded. But when I provide an incorrect username and password
then the error log is read into a file with the correct name but wrong
content. Curl_easy_perform returns CURLE_OK which it should not since
the proxy authentication failed. For example I am trying to download a
test.c file which contains a few lines of code, but instead I get a xml
type error log with that filename (test.c).

I think libcurl should return an error (maybe #67 CURLE_LOGIN_DENIED)
instead of writing the error log to the file and saving it. I am
attaching a verbose log of the transfer to this email and also the
incorrect test.c file that was created in the download directory. I am
using 7.18.2.

Regards,
Sourjo