dev/core#1838 Ensure that no fatal error is triggered if you try to a…

…ccess a merged contact and the contact that it was merged into has been permanently deleted

api/v3/Contact.php

@@ -1308,11 +1308,16 @@ function _civicrm_api3_contact_getmergedto($params) {
     ],
   ])['values'];
   if (!empty($deleteActivity)) {
-    $contactID = civicrm_api3('ActivityContact', 'getvalue', [
-      'activity_id' => $deleteActivity[0]['activity_id.parent_id'],
-      'record_type_id' => 'Activity Targets',
-      'return' => 'contact_id',
-    ]);
+    try {
+      $contactID = civicrm_api3('ActivityContact', 'getvalue', [
+        'activity_id' => $deleteActivity[0]['activity_id.parent_id'],
+        'record_type_id' => 'Activity Targets',
+        'return' => 'contact_id',
+      ]);
+    }
+    catch (\CiviCRM_API3_Exception $e) {
+      Civi::log()->debug('Unable to find original kept contact record');
+    }
   }
   return $contactID;
 }

tests/phpunit/api/v3/ContactTest.php

@@ -4166,6 +4166,29 @@ public function testMergedGet() {
     $this->assertEquals($mergedContactIds, array_keys($result));
   }
 
+  /**
+   * Test retrieving merged contacts.
+   *
+   * The goal here is to start with a contact deleted by merged and find out the contact that is the current version of them.
+   *
+   * @throws \CRM_Core_Exception
+   */
+  public function testMergedGetWithPermanentlyDeletedContact() {
+    $this->contactIDs[] = $this->individualCreate();
+    $this->contactIDs[] = $this->individualCreate();
+    $this->contactIDs[] = $this->individualCreate();
+    $this->contactIDs[] = $this->individualCreate();
+
+    // First do an 'unnatural merge' - they 'like to merge into the lowest but this will mean that contact 0 merged to contact [3].
+    // When the batch merge runs.... the new lowest contact is contact[1]. All contacts will merge into that contact,
+    // including contact[3], resulting in only 3 existing at the end. For each contact the correct answer to 'who did I eventually
+    // wind up being should be [1]
+    $this->callAPISuccess('Contact', 'merge', ['to_remove_id' => $this->contactIDs[0], 'to_keep_id' => $this->contactIDs[3]]);
+    $this->callAPISuccess('Contact', 'delete', ['id' => $this->contactIDs[3], 'skip_undelete' => TRUE]);
+    $result = $this->callAPISuccess('Contact', 'getmergedto', ['sequential' => 1, 'contact_id' => $this->contactIDs[0]]);
+    $this->assertEmpty($result['values']);
+  }
+
   /**
    * Test merging 2 contacts with delete to trash off.
    *