Fix a potential CFRelease(NULL).

net/socket/ssl_client_socket_nss.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file includes code SSLClientSocketNSS::DoVerifyCertComplete() derived
 // from AuthCertificateCallback() in
 // mozilla/security/manager/ssl/src/nsNSSCallbacks.cpp.
 
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
@@ skipping 2365 matching lines @@
           if (!nss_cert) {
             // In the event of an NSS error we make up an OS error and reuse
             // the error handling, below.
             os_error = errSecCreateChainFailed;
             break;
           }
           CERT_AddCertToListTail(*result_certs, nss_cert);
         }
       }
       if (os_error == noErr) {
-        int cert_count = CFArrayGetCount(chain);
-        CFRelease(chain);
+        int cert_count = 0;
+        if (chain) {
+          CFArrayGetCount(chain);

[Ryan Sleevi, 2011/10/25 00:14:16]

nico: Unchecked commit box. Now, |cert_count| is no longer updated.

I'm assuming this should be cert_count = CFArrayGetCount(chain); ?

+          CFRelease(chain);
+        }
         that->net_log_.AddEvent(NetLog::TYPE_SSL_CLIENT_CERT_PROVIDED,
             make_scoped_refptr(new NetLogIntegerParameter("cert_count",
                                                           cert_count)));
         return SECSuccess;
       }
       LOG(WARNING) << "Client cert found, but could not be used: "
                    << os_error;
       if (*result_certs) {
         CERT_DestroyCertList(*result_certs);
         *result_certs = NULL;
@@ skipping 195 matching lines @@
   valid_thread_id_ = base::PlatformThread::CurrentId();
 }
 
 bool SSLClientSocketNSS::CalledOnValidThread() const {
   EnsureThreadIdAssigned();
   base::AutoLock auto_lock(lock_);
   return valid_thread_id_ == base::PlatformThread::CurrentId();
 }
 
 }  // namespace net