On Mon, Aug 4, 2008 at 7:34 PM, Henning Garus <henning.garus@googlemail.com> wrote:
If my understanding of the libdownload code is correct "Command okay" occurs, because the server sends a 200 when libdownload expects something different. But I can't say where.
I've been spending some time trying to reproduce this error, but syncing to a local ftp just works, with and without trailing slash.
I am a bit confused though now, it looks like the code already handles multiple slashes. But well, I will need to investigate it more.
C is not my strong point, but I think the following lines in _ftp_cwd() should take care of multiple slashes:
while (*beg == '/') ++beg, ++i;
Note that you need to download at least 2 files in a row for this to happen. Doing pacman -Sy <package> is enough because a first connection is made for the -Sy, then a second for downloading the package and it breaks there. If you prefer, I have a simpler test case. I just took libdownload source code (for helping debugging, I set debug=true in the Makefile and then installed that), then I extended the samples/dl.c program to reproduce the issue. I attach it here. Then you just need to run it on one ftp server with two files : ./dl ftp://ftp.archlinux.org/core/os/i686/lastsync ftp://ftp.archlinux.org/core/os/i686//packages.txt But it is probably better to run your own ftp server for debugging / playing purpose. ./dl ftp://localhost/foo ftp://localhost//bar The relevant part of the code is indeed the one you showed, but you have to look around it too: for (beg = file + i; beg < end; beg = file + i + 1) { while (*beg == '/') ++beg, ++i; for (++i; file + i < end && file[i] != '/'; ++i) /* nothing */; if(beg < end) e = _ftp_cmd(conn, "CWD %.*s", file + i - beg, beg); if (e != FTP_FILE_ACTION_OK) { _ftp_seterr(e); return (-1); } } In non trailing case, we have : file : /core/os/i686/packages.txt pwd : /core/os/i686 "end" points to the last / in file "beg" points to the first character which differs between file and pwd, which turns out to be exactly the same / as "end". So here we don't have beg < end (we have beg == end) so the whole code above is skipped and everything works fine. In trailing case : file : /core/os/i686//packages.txt pwd : /core/os/i686 end points to the last / in file, and beg to the first different char, which is the slash just before. So here we have beg < end (beg == end - 1 ), so the above code is run, the beg pointer skips the successive /, so eventually points to the "p" of packages So then we don't have beg < end anymore (beg == end + 1), so the ftp_cmd command is not run. But the final check is still run, and here is where our error appears : if (e != FTP_FILE_ACTION_OK) { _ftp_seterr(e); return (-1); } So as you said, at this point e was set to 200 (FTP_OK), but from a previous part of the code. It looks very weird to check for the e error here, while on the previous line, e was only set conditionally (only if beg < end). And about finding where e was last set (to 200), I am not sure, maybe at the beggining of _ftp_cwd : if ((e = _ftp_cmd(conn, "PWD")) != FTP_WORKING_DIRECTORY || Anyway, this was a very long explanation for a small thing in the end :P Maybe it is easier to just run libdownload in debug mode, and play with dl.c and gdb to get sense of it. I still didn't figure out the whole thing yet, and I have still no idea if there is something to fix and how.