Online Pay Now error when used from dashboard checksum link
In 5.3.0 a checksum link to the user dashboard was introduced (https://github.com/civicrm/civicrm-core/pull/12254)
In 5.4.0 a solution for anonymous Online Pay Now link usage was shipped (https://github.com/civicrm/civicrm-core/pull/11578/files)
Unfortunately I believe these two do not work together nicely.
- We send our users a checksum link to their civicrm dashboard (yeah!)
- A user visits his dashboard and clicks Pay Now for a pending contribution
- The users gets the newly introduced error: "Returning since there is no contact attached to this contribution id".
The 5.4.0 fix was discussed in https://issues.civicrm.org/jira/browse/CRM-20697 and it's PR https://github.com/civicrm/civicrm-core/pull/11578 before.