Merge branch 'master' into UI_Update_Eric_Ma

1 files changed, 7 insertions, 1 deletions

diff --git a/src/fields/List.ts b/src/fields/List.ts
index e33627be5..dfd24cf7a 100644
--- a/src/fields/List.ts
+++ b/src/fields/List.ts
@@ -77,10 +77,16 @@ const listHandlers: any = {
                 item[OnUpdate] = updateFunction(list, i + start, item, this);
             }
         }
+        let hintArray: {val : any, index : number}[] = [];
+        for(let i = start; i < start + deleteCount; i++) {
+            hintArray.push({val : list.__fields[i], index : i});
+        }
         const res = list.__fields.splice(start, deleteCount, ...items);
+        // the hint object sends the starting index of the slice and the number
+        // of elements to delete. 
         this[Update](
             items.length === 0 && deleteCount
-                ? { op: '$remFromSet', items: removed, length: list.__fields.length }
+                ? { op: '$remFromSet', items: removed, hint : { start : start, deleteCount : deleteCount }, length: list.__fields.length }
                 : items.length && !deleteCount && start === list.__fields.length
                 ? { op: '$addToSet', items, length: list.__fields.length }
                 : undefined