ftp.size lies after NLST command

[Rehan Khan]

Imported: http://tracker.labix.org/issue312

Reason for Import: patch review

further details: https://blueprints.launchpad.net/smart/+spec/bug-reporting-migration

#msg1159 (view) Author: Seweryn Walentynowicz Date: 2007-06-25.21:29:44

If we define channel, which use ftp protocol, sometimes we got an error:
  "Server reports unexpected size"
It happens when file size in repodata differs from file size reading direct
from FTP session before fetching a file. This size is reading by FTP command
SIZE <filename>. As described in RFC this command returns size in bytes
( same as size in metadata file ) if FTP mode is binary, but in ASCII ftp
mode this size is greater ( including LF appended to end of each line, and
^Z at the end of file ).
 And now in smart fetcher.py code we have:

    ftp.nlst(filename)
    ...
    try:
       total = ftp.size(filename)
       ...
    if size != total:
      raise.Error,_("Server reports unexpected size")

 calling ftp.nlst function from python ftplib set mode of FTP session to ASCII
( send command 'TYPE A' before 'NLST ...' ). After that size reading with
ftp.size was greater than real bytes size of file.
 I've patched my local copy with :
    try:
+ ftp.voidcmd('TYPE I')
       total = ftp.size(filename)
and now all works fine.