Identify limbo-only document updates (#1167)

* Filter out document updates from target association changes

* Move remote-event-modifying methods onto remote event

* Style

* keep limbo docs in remote event

* Implement identification of limbo document updates

* Refactor a bit to handle removes as well

* Drop newline

* Handle synthesized limbo deletes

* Response to feedback

* Appease the style gods

1 files changed, 5 insertions, 1 deletions

diff --git a/Firestore/Source/Core/FSTSyncEngine.mm b/Firestore/Source/Core/FSTSyncEngine.mm
index 8c2aeb2..ca15e64 100644
--- a/Firestore/Source/Core/FSTSyncEngine.mm
+++ b/Firestore/Source/Core/FSTSyncEngine.mm
@@ -349,9 +349,13 @@ static const FSTListenSequenceNumber kIrrelevantSequenceNumber = -1;
         [NSMutableDictionary dictionary];
     FSTDeletedDocument *doc =
         [FSTDeletedDocument documentWithKey:limboKey version:[FSTSnapshotVersion noVersion]];
+    FSTDocumentKeySet *limboDocuments = [[FSTDocumentKeySet keySet] setByAddingObject:doc.key];
     FSTRemoteEvent *event = [[FSTRemoteEvent alloc] initWithSnapshotVersion:SnapshotVersion::None()
                                                               targetChanges:targetChanges
-                                                            documentUpdates:{{limboKey, doc}}];
+                                                            documentUpdates:{
+                                                              { limboKey, doc }
+                                                            }
+                                                             limboDocuments:limboDocuments];
     [self applyRemoteEvent:event];
   } else {
     FSTQueryView *queryView = self.queryViewsByTarget[@(targetID)];