contributions deleted when modifying overdue pledge

Steps to reproduce

Create a pledge & enter a payment against it

Edit the pledge & make the start date earlier such that it is overdue - payment disappears.

This (in Pledge BAO)

is being triggered

// skip payment stuff inedit mode
if ( !isset( $params['id'] ) ||
CRM_Utils_Array::value('is_pledge_pending', $params ) ) {

require_once 'CRM/Pledge/BAO/Payment.php';

//if pledge is pending delete all payments and recreate.
if ( CRM_Utils_Array::value('is_pledge_pending', $params ) )

{ CRM_Pledge_BAO_Payment::deletePayments( $pledge->id ); }

Even though a contribution exists