preliminary undo-redo fixes

src/Util/UndoManager.js

@@ -4,11 +4,12 @@ class ReverseOperation {
   constructor (y, transaction) {
     this.created = new Date()
     const beforeState = transaction.beforeState
-    this.toState = new ID(y.userID, y.ss.getState(y.userID) - 1)
     if (beforeState.has(y.userID)) {
+      this.toState = new ID(y.userID, y.ss.getState(y.userID) - 1)
       this.fromState = new ID(y.userID, beforeState.get(y.userID))
     } else {
-      this.fromState = this.toState
+      this.toState = null
+      this.fromState = null
     }
     this.deletedStructs = transaction.deletedStructs
   }
@@ -30,28 +31,28 @@ function applyReverseOperation (y, scope, reverseBuffer) {
     while (!performedUndo && reverseBuffer.length > 0) {
       let undoOp = reverseBuffer.pop()
       // make sure that it is possible to iterate {from}-{to}
-      y.os.getItemCleanStart(undoOp.fromState)
-      y.os.getItemCleanEnd(undoOp.toState)
-      y.os.iterate(undoOp.fromState, undoOp.toState, op => {
-        if (!op._deleted && isStructInScope(y, op, scope)) {
-          performedUndo = true
-          op._delete(y)
-        }
-      })
+      if (undoOp.fromState !== null) {
+        let start = y.os.getItemCleanStart(undoOp.fromState)
+        y.os.getItemCleanEnd(undoOp.toState)
+        console.log(start)
+        y.os.iterate(undoOp.fromState, undoOp.toState, op => {
+          debugger
+          if (op._deleted && op._redone !== null) {
+            op = op._redone
+          }
+          if (op._deleted === false && isStructInScope(y, op, scope)) {
+            performedUndo = true
+            op._delete(y)
+          }
+        })
+      }
       for (let op of undoOp.deletedStructs) {
         if (
           isStructInScope(y, op, scope) &&
-          op._parent !== y &&
-          !op._parent._deleted &&
-          (
-            op._parent._id.user !== y.userID ||
-            op._parent._id.clock < undoOp.fromState.clock ||
-            op._parent._id.clock > undoOp.fromState.clock
-          )
+          op._parent !== y
         ) {
           performedUndo = true
-          op = op._copy(undoOp.deletedStructs, true)
-          op._integrate(y)
+          op._redo(y)
         }
       }
     }