修复插入行/列报错

src/global/formula.js

@@ -2113,6 +2113,9 @@ const luckysheetformula = {
     },
     functionStrChange: function (txt, type, rc, orient, stindex, step) {
         let _this = this;
+        if (typeof txt !== "string") {
+            return txt; // 保持原内容，不做处理
+        }
 
         if (_this.operatorjson == null) {
             let arr = _this.operator.split("|"),