Add class Sql_mode_save_for_frm_handling

/*

  Save the current sql_mode. Switch off sql_mode flags which can prevent

  normal parsing of VIEWs, expressions in generated columns.

  Restore the old sql_mode on destructor.

*/

class Sql_mode_save_for_frm_handling: public Sql_mode_save

{

public:

  Sql_mode_save_for_frm_handling(THD *thd)

   :Sql_mode_save(thd)

  {

    /*

      - MODE_REAL_AS_FLOAT            affect only CREATE TABLE parsing

      + MODE_PIPES_AS_CONCAT          affect expression parsing

      + MODE_ANSI_QUOTES              affect expression parsing

      + MODE_IGNORE_SPACE             affect expression parsing

      - MODE_IGNORE_BAD_TABLE_OPTIONS affect only CREATE/ALTER TABLE parsing

      * MODE_ONLY_FULL_GROUP_BY       affect execution

      * MODE_NO_UNSIGNED_SUBTRACTION  affect execution

      - MODE_NO_DIR_IN_CREATE         affect table creation only

      - MODE_POSTGRESQL               compounded from other modes

      + MODE_ORACLE                   affects Item creation (e.g for CONCAT)

      - MODE_MSSQL                    compounded from other modes

      - MODE_DB2                      compounded from other modes

      - MODE_MAXDB                    affect only CREATE TABLE parsing

      - MODE_NO_KEY_OPTIONS           affect only SHOW

      - MODE_NO_TABLE_OPTIONS         affect only SHOW

      - MODE_NO_FIELD_OPTIONS         affect only SHOW

      - MODE_MYSQL323                 affect only SHOW

      - MODE_MYSQL40                  affect only SHOW

      - MODE_ANSI                     compounded from other modes

                                      (+ transaction mode)

      ? MODE_NO_AUTO_VALUE_ON_ZERO    affect UPDATEs

      + MODE_NO_BACKSLASH_ESCAPES     affect expression parsing

      + MODE_EMPTY_STRING_IS_NULL     affect expression parsing

    */

    thd->variables.sql_mode&= ~(MODE_PIPES_AS_CONCAT | MODE_ANSI_QUOTES |

                                MODE_IGNORE_SPACE | MODE_NO_BACKSLASH_ESCAPES |

                                MODE_ORACLE | MODE_EMPTY_STRING_IS_NULL);

  };

};

generate_partition_syntax_for_frm:

  sql_mode_t old_mode= thd->variables.sql_mode;

  thd->variables.sql_mode &= ~MODE_ANSI_QUOTES;

mysql_register_view:

    sql_mode_t sql_mode= thd->variables.sql_mode & MODE_ANSI_QUOTES;

    thd->variables.sql_mode&= ~MODE_ANSI_QUOTES;

mysql_make_view:

    thd->variables.sql_mode&= ~(MODE_PIPES_AS_CONCAT | MODE_ANSI_QUOTES |

                                MODE_IGNORE_SPACE | MODE_NO_BACKSLASH_ESCAPES |

                                MODE_ORACLE);

parse_vcol_defs:

  thd->variables.sql_mode &= ~(MODE_NO_BACKSLASH_ESCAPES | MODE_EMPTY_STRING_IS_NULL);

build_frm_image:

  sql_mode_t save_sql_mode= thd->variables.sql_mode;

  thd->variables.sql_mode &= ~MODE_ANSI_QUOTES;