Bugzilla bug 136625: prevent pk11_cert_collect from storing NULL in the

certData.certs array so that pk11_searchCertsAndTrust won't deference a
NULL pointer.  r=relyea.

security/nss/lib/softoken/pkcs11.c

@@ -3642,6 +3642,10 @@ pk11_cert_collect(NSSLOWCERTCertificate *cert,void *arg)
 {
     pk11CertData *cd = (pk11CertData *)arg;
 
+    if (cert == NULL) {
+	return SECSuccess;
+    }
+
     if (cd->certs == NULL) {
 	return SECFailure;
     }