From 0336a92981689d0764d7b6468f2cf35d8dcc3452 Mon Sep 17 00:00:00 2001
From: Monk-Liu <1152761042@qq.com>
Date: Wed, 7 Sep 2022 04:33:16 +0000
Subject: [PATCH] [CP] [bugfix]: avoid select xxx(a''); raise core.

---
 src/sql/parser/sql_parser_mysql_mode.y | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/sql/parser/sql_parser_mysql_mode.y b/src/sql/parser/sql_parser_mysql_mode.y
index d4024bcbd..2b0b54eac 100644
--- a/src/sql/parser/sql_parser_mysql_mode.y
+++ b/src/sql/parser/sql_parser_mysql_mode.y
@@ -620,12 +620,22 @@ expr opt_as column_label
     ParseNode *alias_node = NULL;
     ParseNode *alias_name_node = NULL;
     malloc_terminal_node(alias_name_node, result->malloc_pool_, T_IDENT);
-    dup_node_string($3, alias_name_node, result->malloc_pool_);
+    if (0 == $3->str_len_) {
+      alias_name_node->str_value_ = NULL;
+      alias_name_node->str_len_ = 0;
+    } else {
+      dup_node_string($3, alias_name_node, result->malloc_pool_);
+    }
 
     malloc_non_terminal_node(alias_node, result->malloc_pool_, T_ALIAS, 2, $1, alias_name_node);
     malloc_non_terminal_node($$, result->malloc_pool_, T_EXPR_WITH_ALIAS, 1, alias_node);
     dup_expr_string($$, result, @3.first_column, @3.last_column);
-    dup_node_string($3, alias_node, result->malloc_pool_);
+    if (0 == $3->str_len_) {
+      alias_node->str_value_ = NULL;
+      alias_node->str_len_ = 0;
+    } else {
+      dup_node_string($3, alias_node, result->malloc_pool_);
+    }
     alias_node->param_num_ = 1;
   }
 }