Commit fef1be05 authored by bar@mysql.com/bar.myoffice.izhnet.ru's avatar bar@mysql.com/bar.myoffice.izhnet.ru
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Bug#26711 "Binary content 0x00 sometimes becomes 0x5C 0x00 after dump/load" 

Problem: "SELECT INTO OUTFILE" created incorrect dumps for BLOBs,
so "LOAD DATA" later incorrectly interpreted 0x5C as the second
byte of a multi-byte sequence, instead of escape character.
Fix: adding escaping of multi-byte heads.
parent c762ec3a

mysql-test/r/ctype_big5.result

+13 −0
Original line number Diff line number Diff line
@@ -192,3 +192,16 @@ drop table t1; 
select hex(convert(_big5 0xC84041 using ucs2));

hex(convert(_big5 0xC84041 using ucs2))

003F0041

End of 4.1 tests

create table t1 (a blob);

insert into t1 values (0xEE00);

delete from t1;

select hex(load_file('test/t1.txt'));

hex(load_file('test/t1.txt'))

5CEE5C300A

load data infile 't1.txt' into table t1;

select hex(a) from t1;

hex(a)

EE00

drop table t1;

End of 5.0 tests

mysql-test/t/ctype_big5.test

+17 −1
Original line number Diff line number Diff line
@@ -63,4 +63,20 @@ drop table t1; 
#

select hex(convert(_big5 0xC84041 using ucs2));



# End of 4.1 tests
 
--echo End of 4.1 tests



#

# Bug#26711 "binary content 0x00 sometimes becomes 0x5C 0x00 after dump/load"

#

create table t1 (a blob);

insert into t1 values (0xEE00);

--exec $MYSQL_DUMP --default-character-set=big5 -T $MYSQLTEST_VARDIR/master-data/test test t1

delete from t1;

select hex(load_file('test/t1.txt'));

load data infile 't1.txt' into table t1;

select hex(a) from t1;

--exec rm $MYSQLTEST_VARDIR/master-data/test/t1.txt

--exec rm $MYSQLTEST_VARDIR/master-data/test/t1.sql

drop table t1;



--echo End of 5.0 tests

sql/sql_class.cc

+53 −6
Original line number Diff line number Diff line
@@ -1221,6 +1221,11 @@ select_export::prepare(List<Item> &list, SELECT_LEX_UNIT *u) 
}





#define NEED_ESCAPING(x) ((int) (uchar) (x) == escape_char    || \

                          (int) (uchar) (x) == field_sep_char || \

                          (int) (uchar) (x) == line_sep_char  || \

                          !(x))



bool select_export::send_data(List<Item> &items)

{
@@ -1281,13 +1286,19 @@ bool select_export::send_data(List<Item> &items) 
      if (result_type == STRING_RESULT && escape_char != -1)

      {

        char *pos, *start, *end;



        CHARSET_INFO *res_charset= res->charset();

        CHARSET_INFO *character_set_client= thd->variables.

                                            character_set_client;

        bool check_second_byte= (res_charset == &my_charset_bin) &&

                                 character_set_client->

                                 escape_with_backslash_is_dangerous;

        DBUG_ASSERT(character_set_client->mbmaxlen == 2 ||

                    !character_set_client->escape_with_backslash_is_dangerous);

	for (start=pos=(char*) res->ptr(),end=pos+used_length ;

	     pos != end ;

	     pos++)

	{

#ifdef USE_MB

          CHARSET_INFO *res_charset=res->charset();

	  if (use_mb(res_charset))

	  {

	    int l;
@@ -1298,8 +1309,44 @@ bool select_export::send_data(List<Item> &items) 
	    }

	  }

#endif

	  if ((int) *pos == escape_char || (int) *pos == field_sep_char ||

	      (int) *pos == line_sep_char || !*pos)



          /*

            Special case when dumping BINARY/VARBINARY/BLOB values

            for the clients with character sets big5, cp932, gbk and sjis,

            which can have the escape character (0x5C "\" by default)

            as the second byte of a multi-byte sequence.

            

            If

            - pos[0] is a valid multi-byte head (e.g 0xEE) and

            - pos[1] is 0x00, which will be escaped as "\0",

            

            then we'll get "0xEE + 0x5C + 0x30" in the output file.

            

            If this file is later loaded using this sequence of commands:

            

            mysql> create table t1 (a varchar(128)) character set big5;

            mysql> LOAD DATA INFILE 'dump.txt' INTO TABLE t1;

            

            then 0x5C will be misinterpreted as the second byte

            of a multi-byte character "0xEE + 0x5C", instead of

            escape character for 0x00.

            

            To avoid this confusion, we'll escape the multi-byte

            head character too, so the sequence "0xEE + 0x00" will be

            dumped as "0x5C + 0xEE + 0x5C + 0x30".

            

            Note, in the condition below we only check if

            mbcharlen is equal to 2, because there are no

            character sets with mbmaxlen longer than 2

            and with escape_with_backslash_is_dangerous set.

            DBUG_ASSERT before the loop makes that sure.

          */



          if (NEED_ESCAPING(*pos) ||

              (check_second_byte &&

               my_mbcharlen(character_set_client, (uchar) *pos) == 2 &&

               pos + 1 < end &&

               NEED_ESCAPING(pos[1])))

          {

	    char tmp_buff[2];

	    tmp_buff[0]= escape_char;

strings/ctype-big5.c

+2 −2
Original line number Diff line number Diff line
@@ -6400,7 +6400,7 @@ CHARSET_INFO my_charset_big5_chinese_ci= 
    0,			/* min_sort_char */

    255,		/* max_sort_char */

    ' ',                /* pad char      */

    0,                  /* escape_with_backslash_is_dangerous */

    1,                  /* escape_with_backslash_is_dangerous */

    &my_charset_big5_handler,

    &my_collation_big5_chinese_ci_handler

};
@@ -6433,7 +6433,7 @@ CHARSET_INFO my_charset_big5_bin= 
    0,			/* min_sort_char */

    255,		/* max_sort_char */

    ' ',                /* pad char      */

    0,                  /* escape_with_backslash_is_dangerous */

    1,                  /* escape_with_backslash_is_dangerous */

    &my_charset_big5_handler,

    &my_collation_mb_bin_handler

};

strings/ctype-gbk.c

+2 −2
Original line number Diff line number Diff line
@@ -10046,7 +10046,7 @@ CHARSET_INFO my_charset_gbk_chinese_ci= 
    0,			/* min_sort_char */

    255,		/* max_sort_char */

    ' ',                /* pad char      */

    0,                  /* escape_with_backslash_is_dangerous */

    1,                  /* escape_with_backslash_is_dangerous */

    &my_charset_handler,

    &my_collation_ci_handler

};
@@ -10078,7 +10078,7 @@ CHARSET_INFO my_charset_gbk_bin= 
    0,			/* min_sort_char */

    255,		/* max_sort_char */

    ' ',                /* pad char      */

    0,                  /* escape_with_backslash_is_dangerous */

    1,                  /* escape_with_backslash_is_dangerous */

    &my_charset_handler,

    &my_collation_mb_bin_handler

};