!4755 【测试类型：SQL功能】【测试版本：5.1.1】【后台及工具支持切换运行日志为中文日志】 enable_nls参数控制不完全，语法类报错无法关闭翻译功能

Merge pull request !4755 from Netsah/bug_I8RCI9

src/common/backend/parser/scan.l

@@ -74,6 +74,9 @@ const uint16 ScanKeywordTokens[] = {
                (YYSTYPE * yylval_param, YYLTYPE * yylloc_param , yyscan_t yyscanner)
 #endif
 
+#undef _
+#define _(str) ((!u_sess->attr.attr_common.enable_nls) || in_error_recursion_trouble())?str:gettext(str)
+
 /*
  * Set the type of yyextra.  All state variables used by the scanner should
  * be in yyextra, *not* statically allocated.