Import contribution choking on certain errors, with suggested fix

When Contribution Import receives certain errors it isn't handling them but just proceeding forward, leading to a crash and un-helpful PEAR error message.

The problem is around line 81 of /civicrm/api/v3/Contribution.php in function civicrm_api3_contribution_create, and adding error handling code similar to this will fix the problem:

$contribution = CRM_Contribute_BAO_Contribution::create($values, $ids);

++ //Needs to check whether $contribution returned an error
++ if (isset($contribution->_errors)) return civicrm_api3_create_error($contribution->_errors[0]['message']);

if(!empty($params['use_default_price_set']) && empty($params['id'] )){
_civicrm_api3_contribution_createdefaultlineitem($params, $contribution);

Maybe that should just be something like if (isset($contribution->_errors)) return $contribution; but you guys can sort out that type of thing better than I.