CRM-21804 improve error handling on duplicate contribution.
authoreileen <emcnaughton@wikimedia.org>
Mon, 26 Feb 2018 02:32:35 +0000 (15:32 +1300)
committereileen <emcnaughton@wikimedia.org>
Mon, 26 Feb 2018 05:51:43 +0000 (18:51 +1300)
commit77beddbee3d88da18e367d6597f1596c1de33969
treed9e58ada9f92c5cc378bc70a14cbf60755381e8c
parentbc17b73e442ebbec13b08acb7093f03a66495b96
CRM-21804 improve error handling on duplicate contribution.

Duplicate contributions are a really not handled well anywhere in the form layer.
The CRM_Core_Error winds up using the fatal template, which has the same end
result for form users as if an exception were thrown, let's switch.

Note that this appears to be the only scenario when an error would
be returned so we can simply drop that handling
CRM/Contribute/BAO/Contribution.php
CRM/Contribute/Form/Contribution/Confirm.php
CRM/Event/Cart/Form/Checkout/Payment.php