Re-using the cURL handle breaks all but the first request

[xrstf]

I am using SabreDAV 2.0.5 with Sabre HTTP 2.0.4 on PHP 5.6 (Win x64). This is my test code, which should just check if a file exists (expected to 404) and then create it:

require 'vendor/autoload.php';

$client = new Sabre\DAV\Client(array(
    'baseUri' => 'http://my.webdav.host/',
    'proxy'   => 'http://127.0.0.1:8888/'   // for debugging with Fiddler
));

$client->request('HEAD', '/foo.txt'); // throws NotFound exception, as expected
$client->request('PUT', '/foo.txt', 'my content');

We are -- for testing -- tunneling WebDAV through nginx. Unexpectedly, we get an HTTP 500 for the PUT request, because it looks like this in Fiddler

PUT http://my.webdav.host/foo.txt HTTP/1.1
Host: my.webdav.host
Accept: */*
Connection: Keep-Alive

There is no content and no Content-Length header, making the nginx barf.

I traced the problem down to the Sabre\HTTP\Client class and its recycling of the cURL handle.

protected function doRequest(RequestInterface $request) {

    $settings = $this->createCurlSettingsArray($request);

    if (!$this->curlHandle) {
        $this->curlHandle = curl_init();
    }

    // ...snip...
}

If I disable the if and always recreate a new cURL handle, everything works as expected.

Since the curlHandle is private, I have very little chance to work around this except creating a new SabreDAV client for every single request.

[evert]

Weird!

[Hywan]

@xrstf What is your version of cURL please?

[xrstf]

I'm using PHP 5.6.1:

cURL support     => enabled
cURL Information => 7.38.0
Age              => 3
AsynchDNS        => Yes
CharConv         => No
Debug            => No
GSS-Negotiate    => No
IDN              => Yes
IPv6             => Yes
krb4             => No
Largefile        => Yes
libz             => Yes
NTLM             => Yes
NTLMWB           => No
SPNEGO           => Yes
SSL              => Yes
SSPI             => Yes
TLS-SRP          => No
Protocols        => dict, file, ftp, ftps, gopher, http, https, imap, imaps, ldap, pop3, pop3s, rtsp, scp, sftp, smtp, smtps, telnet, tftp
Host             => i386-pc-win32
SSL Version      => OpenSSL/1.0.1i
ZLib Version     => 1.2.7.3
libSSH Version   => libssh2/1.4.3

[Hywan]

@xrstf If you add the CURLOPT_FORBID_REUSE or CURLOPT_FRESH_CONNECT constants, does it solve your issue?

[evert]

@Hywan even if that solved his issue, I think the most important thing is that we attempt to reproduce this and figure out why it's happening in the first place. On my machine, this is definitely not a problem...

[Hywan]

@evert I am not able to reproduce the bug neither, that's why I was asking @xrstf to see if these options should solve the problem at first. If no, I will dig deeper.

[andreaswolf]

I can reproduce this with 4.0.0-alpha1. It is fixed on most recent master, but sabre/dav still uses 4.0.0-alpha1. Adding the following to composer.json updates sabre/http to master instead:

"require": {
  "sabre/http": "dev-master as 4.0.0-alpha1"
}

I’m using PHP 5.5.24 on Fedora 20 (cURL 7.32.0). As some people reported not being able to reproduce this: If you have anything I can do to help testing this, just contact me (here or via mail).

[evert]

Hi Andreas,

I'm releasing 4.0.0-alpha2 right now to solve this.

[evert]

Oh my I never realized this was the same ticket as #47 :(

On the bright side, the unittests are now changed to catch issues similar to this. I'm very sorry you had to wait this long.

[evert]

Just released the second alpha