These are problems known to exist at the time of this release. Feel free to
join in and help us correct one or more of these! Also be sure to check the
changelog of the current development status, as one or more of these problems
may have been fixed since this was written!
44. --ftp-method nocwd does not handle URLs ending with a slash properly (it
should list the contents of that directory). See test case 351.
43. There seems to be a problem when connecting to the Microsoft telnet server.
http://curl.haxx.se/bug/view.cgi?id=1720605
41. When doing an operation over FTP that requires the ACCT command (but not
when logging in), the operation will fail since libcurl doesn't detect this
and thus fails to issue the correct command:
http://curl.haxx.se/bug/view.cgi?id=1693337
39. Steffen Rumler's Race Condition in Curl_proxyCONNECT:
http://curl.haxx.se/mail/lib-2007-01/0045.html
38. Kumar Swamy Bhatt's problem in ftp/ssl "LIST" operation:
http://curl.haxx.se/mail/lib-2007-01/0103.html
37. Having more than one connection to the same host when doing NTLM
authentication (with performs multiple "passes" and authenticates a
connection rather than a HTTP request), and particularly when using the
multi interface, there's a risk that libcurl will re-use a wrong connection
when doing the different passes in the NTLM negotiation and thus fail to
negotiate (in seemingly mysterious ways).
35. Both SOCKS5 and SOCKS4 proxy connections are done blocking, which is very
bad when used with the multi interface.
34. The SOCKS4 connection codes don't properly acknowledge (connect) timeouts.
Also see #12. According to bug #1556528, even the SOCKS5 connect code does
not do it right: http://curl.haxx.se/bug/view.cgi?id=1556528,
33. Doing multi-pass HTTP authentication on a non-default port does not work.
This happens because the multi-pass code abuses the redirect following code
for doing multiple requests, and when we following redirects to an absolute
URL we must use the newly specified port and not the one specified in the
original URL. A proper fix to this would need to separate the negotiation
"redirect" from an actual redirect.
32. (At least on Windows) If libcurl is built with c-ares and there's no DNS
server configured in the system, the ares_init() call fails and thus
curl_easy_init() fails as well. This causes weird effects for people who use
numerical IP addresses only.
31. "curl-config --libs" will include details set in LDFLAGS when configure is
run that might be needed only for building libcurl. Similarly, it might
include options that perhaps aren't suitable both for static and dynamic
linking. Further, curl-config --cflags suffers from the same effects with
CFLAGS/CPPFLAGS.
30. You need to use -g to the command line tool in order to use RFC2732-style
IPv6 numerical addresses in URLs.
29. IPv6 URLs with zone ID is not supported.
http://www.ietf.org/internet-drafts/draft-fenner-literal-zone-02.txt
specifies the use of a plus sign instead of a percent when specifying zone
IDs in URLs to get around the problem of percent signs being
special. According to the reporter, Firefox deals with the URL _with_ a
percent letter (which seems like a blatant URL spec violation).
See http://curl.haxx.se/bug/view.cgi?id=1371118
26. NTLM authentication using SSPI (on Windows) when (lib)curl is running in
"system context" will make it use wrong(?) user name - at least when compared
to what winhttp does. See http://curl.haxx.se/bug/view.cgi?id=1281867
23. SOCKS-related problems:
A) libcurl doesn't support SOCKS for IPv6.
B) libcurl doesn't support FTPS over a SOCKS proxy.
C) We don't have any test cases for SOCKS proxy.
E) libcurl doesn't support active FTP over a SOCKS proxy
We probably have even more bugs and lack of features when a SOCKS proxy is
used.
22. Sending files to a FTP server using curl on VMS, might lead to curl
complaining on "unaligned file size" on completion. The problem is related
to VMS file structures and the perceived file sizes stat() returns. A
possible fix would involve sending a "STRU VMS" command.
http://curl.haxx.se/bug/view.cgi?id=1156287
21. FTP ASCII transfers do not follow RFC959. They don't convert the data
accordingly (not for sending nor for receiving). RFC 959 section 3.1.1.1
clearly describes how this should be done:
The sender converts the data from an internal character representation to
the standard 8-bit NVT-ASCII representation (see the Telnet
specification). The receiver will convert the data from the standard
form to his own internal form.
Since 7.15.4 at least line endings are converted.
16. FTP URLs passed to curl may contain NUL (0x00) in the RFC 1738 <user>,
<password>, and <fpath> components, encoded as "%00". The problem is that
curl_unescape does not detect this, but instead returns a shortened C
string. From a strict FTP protocol standpoint, NUL is a valid character
within RFC 959 <string>, so the way to handle this correctly in curl would
be to use a data structure other than a plain C string, one that can handle
embedded NUL characters. From a practical standpoint, most FTP servers
would not meaningfully support NUL characters within RFC 959 <string>,
anyway (e.g., UNIX pathnames may not contain NUL).
14. Test case 165 might fail on system which has libidn present, but with an
old iconv version (2.1.3 is a known bad version), since it doesn't recognize
the charset when named ISO8859-1. Changing the name to ISO-8859-1 makes the
test pass, but instead makes it fail on Solaris hosts that use its native
iconv.
13. curl version 7.12.2 fails on AIX if compiled with --enable-ares.
The workaround is to combine --enable-ares with --disable-shared
12. When connecting to a SOCKS proxy, the (connect) timeout is not properly
acknowledged after the actual TCP connect (during the SOCKS "negotiate"
phase).
10. To get HTTP Negotiate authentication to work fine, you need to provide a
(fake) user name (this concerns both curl and the lib) because the code
wrongly only considers authentication if there's a user name provided.
http://curl.haxx.se/bug/view.cgi?id=1004841. How?
http://curl.haxx.se/mail/lib-2004-08/0182.html
8. Doing resumed upload over HTTP does not work with '-C -', because curl
doesn't do a HEAD first to get the initial size. This needs to be done
manually for HTTP PUT resume to work, and then '-C [index]'.
7. CURLOPT_USERPWD and CURLOPT_PROXYUSERPWD have no way of providing user names
that contain a colon. This can't be fixed easily in a backwards compatible
way without adding new options (and then, they should most probably allow
setting user name and password separately).
6. libcurl ignores empty path parts in FTP URLs, whereas RFC1738 states that
such parts should be sent to the server as 'CWD ' (without an argument).
The only exception to this rule, is that we knowingly break this if the
empty part is first in the path, as then we use the double slashes to
indicate that the user wants to reach the root dir (this exception SHALL
remain even when this bug is fixed).
5. libcurl doesn't treat the content-length of compressed data properly, as
it seems HTTP servers send the *uncompressed* length in that header and
libcurl thinks of it as the *compressed* length. Some explanations are here:
http://curl.haxx.se/mail/lib-2003-06/0146.html
2. If a HTTP server responds to a HEAD request and includes a body (thus
violating the RFC2616), curl won't wait to read the response but just stop
reading and return back. If a second request (let's assume a GET) is then
immediately made to the same server again, the connection will be re-used
fine of course, and the second request will be sent off but when the
response is to get read, the previous response-body is what curl will read
and havoc is what happens.
More details on this is found in this libcurl mailing list thread:
http://curl.haxx.se/mail/lib-2002-08/0000.html