Automatically handle deprecated trxn_id on civicrm_contribution_recur

mjwshared.php

@@ -28,6 +28,9 @@ function mjwshared_civicrm_config(&$config) {
   Civi::dispatcher()->addListener('hook_civicrm_buildAsset', 'mjwshared_symfony_civicrm_buildAsset', -990);
   // This should run before (almost) anything else as we're loading shared libraries
   Civi::dispatcher()->addListener('hook_civicrm_coreResourceList', 'mjwshared_symfony_civicrm_coreResourceList', 1000);
+
+  \Civi::dispatcher()->addListener('civi.dao.preUpdate', 'mjwshared_symfony_preUpdateInsert');
+  \Civi::dispatcher()->addListener('civi.dao.preInsert', 'mjwshared_symfony_preUpdateInsert');
 }
 
 /**
@@ -264,3 +267,24 @@ function mjwshared_civicrm_buildForm($formName, &$form) {
 
   \Civi::resources()->addVars('payment', $jsVars);
 }
+
+/**
+ * @param \Civi\Core\DAO\Event\PreUpdate $event
+ */
+function mjwshared_symfony_preUpdateInsert(\Civi\Core\DAO\Event\PreUpdate $event) {
+  if ($event->object instanceof CRM_Contribute_BAO_ContributionRecur) {
+    // Handle deprecated civicrm_contribution_recur.trxn_id and set it to match processor_id if empty
+    if (!empty($event->object->processor_id) && empty($event->object->trxn_id)) {
+      // We set trxn_id to match processor_id as it is still used in some places
+      $event->object->trxn_id = $event->object->processor_id;
+    }
+    elseif (!empty($event->object->trxn_id) && empty($event->object->processor_id)) {
+      // warn old set
+      CRM_Core_Error::deprecatedFunctionWarning('civicrm_contribution_recur.processor_id', 'civicrm_contribution_recur.trxn_id');
+    }
+    if (!empty($event->object->trxn_id) && !empty($event->object->processor_id) && ($event->object->trxn_id !== $event->object->processor_id)) {
+      // Warn set to different values
+      CRM_Core_Error::deprecatedWarning("Recur ID: {$event->object->id}; civicrm_contribution_recur processor_id is different to trxn_id. trxn_id is deprecated and should be empty or match processor_id");
+    }
+  }
+}