Fix size calculation when headers are provided

When headers are provided to data(), we include their size in the initial data
size calculation. However, because the headers are sent separately in that
case, we need to remove them from $size before sending the remaining data.

Fixes #27

Author: jparise

Net/SMTP.php

@@ -1034,6 +1034,9 @@ public function data($data, $headers = null)
             if (PEAR::isError($result = $this->send($headers . "\r\n\r\n"))) {
                 return $result;
             }
+
+            /* Subtract the headers size now that they've been sent. */
+            $size -= strlen($headers) + 4;
         }
 
         /* Now we can send the message body data. */

tests/basic.phpt

@@ -29,7 +29,8 @@ if (PEAR::isError($res = $smtp->rcptTo(TEST_TO))) {
         $res->getMessage() . "\n");
 }
 
-if (PEAR::isError($smtp->data('Subject: ' . TEST_SUBJECT . "\r\n\r\n" . TEST_BODY))) {
+$headers = 'Subject: ' . TEST_SUBJECT;
+if (PEAR::isError($smtp->data(TEST_BODY, $headers))) {
     die("Unable to send data\n");
 }