[bugfix beta] Fetch cancels unload

addon/-private/system/store.js

@@ -855,6 +855,18 @@ Store = Service.extend({
       seeking[internalModel.id] = pendingItem;
     }
 
+    for (let i = 0; i < totalItems; i++) {
+      let internalModel = internalModels[i];
+      // We may have unloaded the record after scheduling this fetch, in which
+      // case we must cancel the destory.  This is because we require a record
+      // to build a snapshot.  This is not fundamental: this cancelation code
+      // can be removed when snapshots can be created for internal models that
+      // have no records.
+      if (internalModel.hasScheduledDestroy()) {
+        internalModels[i].cancelDestroy();
+      }
+    }
+
     function _fetchRecord(recordResolverPair) {
       let recordFetch = store._fetchRecord(
         recordResolverPair.internalModel,

tests/integration/records/unload-test.js

@@ -2089,3 +2089,31 @@ test('unload invalidates link promises', function(assert) {
     })
   );
 });
+
+test('fetching records cancels unloading', function(assert) {
+  env.adapter.findRecord = (store, type, id) => {
+    assert.equal(type, Person, 'findRecord(_, type) is correct');
+    assert.deepEqual(id, '1', 'findRecord(_, _, id) is correct');
+
+    return  {
+      data: {
+        id: 1,
+        type: 'person'
+      }
+    }
+  };
+
+  run(() =>
+    env.store.push({
+      data: {
+        id: 1,
+        type: 'person'
+      }
+    })
+  );
+
+  return run(() =>
+    env.store.findRecord('person', 1, { backgroundReload: true })
+      .then(person => person.unloadRecord())
+  );
+});