do not split deltas in multiselct action

node_modules/ace/lib/ace/editor.js

@@ -966,8 +966,11 @@ var Editor = function(renderer, session) {
             var transform = mode.transformAction(session.getState(cursor.row), 'insertion', this, session, text);
             if (transform) {
                 if (text !== transform.text) {
-                    this.session.mergeUndoDeltas = false;
-                    this.$mergeNextCommand = false;
+                    // keep automatic insertion in a separate delta, unless it is in multiselect mode
+                    if (!this.inVirtualSelectionMode) {
+                        this.session.mergeUndoDeltas = false;
+                        this.mergeNextCommand = false;
+                    }
                 }
                 text = transform.text;