[CP] fix group_concat, wm_concat bugs

src/sql/engine/aggregate/ob_aggregate_function.cpp

@@ -333,15 +333,13 @@ int ObAggregateFunction::init(const int64_t input_column_count, const ObAggrExpr
     ret = OB_INVALID_ARGUMENT;
     LOG_WARN("expr_ctx is valid", K_(expr_ctx.phy_plan_ctx), K_(expr_ctx.my_session), K_(expr_ctx.calc_buf));
   } else {
+    expr_ctx_ = expr_ctx;
     if (share::is_oracle_mode()) {
       group_concat_max_len_ = OB_DEFAULT_GROUP_CONCAT_MAX_LEN_FOR_ORACLE;
-    } else {
-      group_concat_max_len_ = OB_DEFAULT_GROUP_CONCAT_MAX_LEN;
-    }
-    if (OB_FAIL(expr_ctx.my_session_->get_group_concat_max_len(group_concat_max_len_))) {
+    } else if (OB_FAIL(expr_ctx.my_session_->get_group_concat_max_len(group_concat_max_len_))) {
       LOG_WARN("fail to get group concat max len", K(ret));
-    } else {
-      expr_ctx_ = expr_ctx;
+    } else if (group_concat_max_len_ >= CONCAT_STR_BUF_LEN - 1) {
+      group_concat_max_len_ = CONCAT_STR_BUF_LEN - 2;
     }
   }
   // add aggr columns

src/sql/resolver/expr/ob_raw_expr_deduce_type.cpp

@@ -1064,6 +1064,7 @@ int ObRawExprDeduceType::visit(ObAggFunRawExpr& expr)
           ret = OB_ERR_UNEXPECTED;
           LOG_WARN("get unexpected NULL", K(param_expr), K(my_session_), K(ret));
         } else {
+          result_type.set_accuracy(ObAccuracy::MAX_ACCURACY2[lib::is_oracle_mode()][ObLobType]);
           result_type.set_collation_type(my_session_->get_nls_collation());
           result_type.set_calc_collation_type(my_session_->get_nls_collation());
           result_type.set_collation_level(CS_LEVEL_IMPLICIT);