Re: pkg/43013: Clarification of URL handling for pkg_add/pkgin

[brook%biology.nmsu.edu@localhost (Brook Milligan)]

The following reply was made to PR pkg/43013; it has been noted by GNATS.

From: brook%biology.nmsu.edu@localhost (Brook Milligan)
To: gnats-bugs%NetBSD.org@localhost
Cc: joerg%NetBSD.org@localhost, gnats-admin%netbsd.org@localhost, 
pkgsrc-bugs%netbsd.org@localhost,
        brook%nmsu.edu@localhost
Subject: Re: pkg/43013: Clarification of URL handling for pkg_add/pkgin
Date: Fri, 19 Mar 2010 22:14:30 -0600

 Joerg,
 
 I applied your patch, but the same problem remains.  As a result, I've
 been looking over the code some more and have a few points to note.
 
 I think I have narrowed down the problem that I am seeing.  Here is
 one section of the calling sequence as indicated by some printf()
 statements I added (note that the URL I gave to pkg_add was
 ftp://localhost/All/emacs and that the file All/emacs-23.1nb2.tgz
 exists in the ftp login directory):
 
      fetchList(): pattern=emacs*, flags=c
      fetchListFTP(): NLST
      ftp_request(): op=NLST, op_arg=emacs*, flags=c
      ftp_request(): path=/All
      ftp_cwd(): path=/All, subdir=1
      ftp_cwd(): path=All
      ftp_cwd(): conn->ftp_home=(null)
      ftp_cwd(): strchr(path, '/')=(null)
 
 I think the key point here is the subdir argument to ftp_cwd, which is
 initialized by the expression 'op_arg != NULL' in ftp_request().
 Since I am requesting /All/emacs* that value seems correct to indicate
 that the path requested for cwd (i.e., /All) is a subdirectory not a
 file.  However, here is the code that is executed within ftp_cwd
 immediately after the printf() above:
 
        /* Simple case: still in the home directory and no directory change. */
        if (conn->ftp_home == NULL && strchr(path, '/') == NULL)
                return 0;
 
 Clearly, this condition holds and ftp_cwd immediately exits.
 
 My analysis of this suggests, however, that only if subdir=0 should
 this exit immediately.  When there is not a '/' in the path, there are
 two cases: (i) the path points to a file (i.e., subdir=0) or (ii) the
 path points to the directory in which the file resides (i.e.,
 subdir=1).  In the example I have above, the second case holds and one
 CWD command, not zero, should be emitted.
 
 If all this logic is correct, I would expect something like the
 following instead:
 
 --- ftp.c
 +++ ftp.c.orig
 @@ -304,7 +304,7 @@
        ++path;
  
        /* Simple case: still in the home directory and no directory change. */
 -      if (conn->ftp_home == NULL && strchr(path, '/') == NULL)
 +      if (conn->ftp_home == NULL && strchr(path, '/') == NULL && !subdir)
                return 0;
  
        if ((e = ftp_cmd(conn, "PWD\r\n")) != FTP_WORKING_DIRECTORY ||
 
 Indeed, that change makes this example complete correctly.
 
 Since you are much more familiar with all of this code than I, please
 verify that my logic is correct and that there are not other
 implications of the change I suggest.
 
 Thanks alot for taking a look at this.
 
 Cheers,
 Brook