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MDEV-10306 Wrong results with combination of CONCAT, SUBSTR and CONVERT in subquery

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The bug happens because of a combination of unfortunate circumstances:

1. Arguments args[0] and args[2] of Item_func_concat point recursively
(through Item_direct_view_ref's) to the same Item_func_conv_charset.
Both args[0]->args[0]->ref[0] and args[2]->args[0]->ref[0] refer to
this Item_func_conv_charset.

2. When Item_func_concat::args[0]->val_str() is called,
Item_func_conv_charset::val_str() writes its result to
Item_func_conc_charset::tmp_value.

3. Then, for optimization purposes (to avoid copying),
Item_func_substr::val_str() initializes Item_func_substr::tmp_value
to point to the buffer fragment owned by Item_func_conv_charset::tmp_value
Item_func_substr::tmp_value is returned as a result of
Item_func_concat::args[0]->val_str().

4. Due to optimization to avoid memory reallocs,
Item_func_concat::val_str() remembers the result of args[0]->val_str()
in "res" and further uses "res" to collect the return value.

5. When Item_func_concat::args[2]->val_str() is called,
Item_func_conv_charset::tmp_value gets overwritten (see #1),
which effectively overwrites args[0]'s Item_func_substr::tmp_value (see #3),
which effectively overwrites "res" (see #4).

This patch does the following:

a. Changes Item_func_conv_charset::val_str(String *str) to use
   tmp_value and str the other way around. After this change tmp_value
   is used to store a temporary result, while str is used to return the value.
   The fixes the second problem (without SUBSTR):
     SELECT CONCAT(t2,'-',t2) c2
       FROM (SELECT CONVERT(t USING latin1) t2 FROM t1) sub;
   As Item_func_concat::val_str() supplies two different buffers when calling
   args[0]->val_str() and args[2]->val_str(), in the new reduction the result
   created during args[0]->val_str() does not get overwritten by
   args[2]->val_str().

b. Fixing the same problem in val_str() for similar classes

   Item_func_to_base64
   Item_func_from_base64
   Item_func_weight_string
   Item_func_hex
   Item_func_unhex
   Item_func_quote
   Item_func_compress
   Item_func_uncompress
   Item_func_des_encrypt
   Item_func_des_decrypt
   Item_func_conv_charset
   Item_func_reverse
   Item_func_soundex
   Item_func_aes_encrypt
   Item_func_aes_decrypt
   Item_func_buffer

c. Fixing Item_func::val_str_from_val_str_ascii() the same way.
   Now Item_str_ascii_func::ascii_buff is used for temporary value,
   while the parameter passed to val_str() is used to return the result.
   This fixes the same problem when conversion (from ASCII to e.g. UCS2)
   takes place. See the ctype_ucs.test for example queries that returned
   wrong results before the fix.

d. Some Item_func descendand classes had temporary String buffers
   (tmp_value and tmp_str), but did not really use them.
   Removing these temporary buffers from:

   Item_func_decode_histogram
   Item_func_format
   Item_func_binlog_gtid_pos
   Item_func_spatial_collection:

e. Removing Item_func_buffer::tmp_value, because it's not used any more.

f. Renaming Item_func_[un]compress::buffer to "tmp_value",
   for consistency with other classes.

Note, this patch does not fix the following classes
(although they have a similar problem):

   Item_str_conv
   Item_func_make_set
   Item_char_typecast

They have a complex implementations and simple swapping between "tmp_value"
and "str" won't work. These classes will be fixed separately.
This commit is contained in:
Alexander Barkov 2017-06-19 12:45:32 +04:00
parent f0ad93403f
commit 3a37afec29
13 changed files with 438 additions and 130 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
mysql-test/r/ctype_ucs.result
View File

@ -5552,5 +5552,22 @@ SELECT 'a','aa';
a aa a aa
a aa a aa
# #
# MDEV-10306 Wrong results with combination of CONCAT, SUBSTR and CONVERT in subquery
#
SET NAMES utf8, character_set_connection=ucs2;
SET @save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch=_utf8'derived_merge=on';
CREATE TABLE t1 (t VARCHAR(10) CHARSET latin1);
INSERT INTO t1 VALUES('abcdefghi');
SET NAMES utf8, character_set_connection=ucs2;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT HEX(t) t2 FROM t1) sub;
c2
616263646566676869-616263646566676869
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT TO_BASE64(t) t2 FROM t1) sub;
c2
YWJjZGVmZ2hp-YWJjZGVmZ2hp
DROP TABLE t1;
SET optimizer_switch=@save_optimizer_switch;
#
# End of 10.0 tests # End of 10.0 tests
# #

113
mysql-test/r/func_concat.result
View File

@ -149,3 +149,116 @@ CALL p1();
########################################40100.000 ########################################40100.000
DROP PROCEDURE p1; DROP PROCEDURE p1;
# End of 5.1 tests # End of 5.1 tests
#
# Start of 10.0 tests
#
#
# MDEV-10306 Wrong results with combination of CONCAT, SUBSTR and CONVERT in subquery
#
SET @save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch='derived_merge=on';
CREATE TABLE t1 (t VARCHAR(10) CHARSET latin1);
INSERT INTO t1 VALUES('1234567');
SELECT CONCAT(SUBSTR(t2, 1, 3), SUBSTR(t2, 5)) c1,
CONCAT(SUBSTR(t2,1,3),'---',SUBSTR(t2,5)) c2
FROM (SELECT CONVERT(t USING latin1) t2 FROM t1) sub;
c1 c2
123567 123---567
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT CONVERT(t USING latin1) t2 FROM t1) sub;
c2
1234567-1234567
DROP TABLE t1;
CREATE TABLE t1 (t VARCHAR(10) CHARSET latin1);
INSERT INTO t1 VALUES('1234567');
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT CONVERT(t USING latin1) t2 FROM t1) sub;
c2
1234567-1234567
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT REVERSE(t) t2 FROM t1) sub;
c2
7654321-7654321
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT SOUNDEX(t) t2 FROM t1) sub;
c2
-
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT TO_BASE64(t) t2 FROM t1) sub;
c2
MTIzNDU2Nw==-MTIzNDU2Nw==
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT WEIGHT_STRING(t) t2 FROM t1) sub;
c2
1234567-1234567
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT HEX(t) t2 FROM t1) sub;
c2
31323334353637-31323334353637
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT QUOTE(t) t2 FROM t1) sub;
c2
'1234567'-'1234567'
DROP TABLE t1;
CREATE TABLE t1 (t VARCHAR(32) CHARSET latin1);
INSERT INTO t1 VALUES(TO_BASE64('abcdefghi'));
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT FROM_BASE64(t) t2 FROM t1) sub;
c2
abcdefghi-abcdefghi
DROP TABLE t1;
CREATE TABLE t1 (t VARCHAR(32) CHARSET latin1);
INSERT INTO t1 VALUES(HEX('abcdefghi'));
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT UNHEX(t) t2 FROM t1) sub;
c2
abcdefghi-abcdefghi
DROP TABLE t1;
CREATE TABLE t1 (t VARCHAR(30) CHARSET latin1);
INSERT INTO t1 VALUES('test');
SELECT LENGTH(CONCAT(t2)) c2 FROM (SELECT AES_ENCRYPT(t,'x') t2 FROM t1) sub;
c2
16
SELECT LENGTH(CONCAT(t2,'-',t2)) c2 FROM (SELECT AES_ENCRYPT(t,'x') t2 FROM t1) sub;
c2
33
SELECT LENGTH(CONCAT(t2,'--',t2)) c2 FROM (SELECT AES_ENCRYPT(t,'x') t2 FROM t1) sub;
c2
34
SELECT LENGTH(CONCAT(t2)) c2 FROM (SELECT AES_DECRYPT(AES_ENCRYPT(t,'x'),'x') t2 FROM t1) sub;
c2
4
SELECT LENGTH(CONCAT(t2,'-',t2)) c2 FROM (SELECT AES_DECRYPT(AES_ENCRYPT(t,'x'),'x') t2 FROM t1) sub;
c2
9
SELECT LENGTH(CONCAT(t2,'--',t2)) c2 FROM (SELECT AES_DECRYPT(AES_ENCRYPT(t,'x'),'x') t2 FROM t1) sub;
c2
10
DROP TABLE t1;
CREATE TABLE t1 (t VARCHAR(64) CHARSET latin1);
INSERT INTO t1 VALUES('123456789');
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT MD5(t) t2 FROM t1) sub;
c2
25f9e794323b453885f5181f1b624d0b-25f9e794323b453885f5181f1b624d0b
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT FORMAT(t,2) t2 FROM t1) sub;
c2
123,456,789.00-123,456,789.00
DROP TABLE t1;
CREATE TABLE t1 (t VARCHAR(32) CHARSET latin1);
INSERT INTO t1 VALUES('abcdefghi');
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT INSERT(t,3,4,'xxx') t2 FROM t1) sub;
c2
abxxxghi-abxxxghi
DROP TABLE t1;
CREATE TABLE t1 (t VARCHAR(10) CHARSET latin1);
INSERT INTO t1 VALUES('abcdefghi');
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT LEFT(t,10) t2 FROM t1) sub;
c2
abcdefghi-abcdefghi
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT RIGHT(t,10) t2 FROM t1) sub;
c2
abcdefghi-abcdefghi
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT SUBSTR(t,1,10) t2 FROM t1) sub;
c2
abcdefghi-abcdefghi
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT LTRIM(t) t2 FROM t1) sub;
c2
abcdefghi-abcdefghi
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT RTRIM(t) t2 FROM t1) sub;
c2
abcdefghi-abcdefghi
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT TRIM(t) t2 FROM t1) sub;
c2
abcdefghi-abcdefghi
DROP TABLE t1;
SET optimizer_switch=@save_optimizer_switch;

18
mysql-test/r/func_crypt.result
View File

@ -106,3 +106,21 @@ OLD_PASSWORD(c1) PASSWORD(c1)
77023ffe214c04ff *82E58A2C08AAFE72C8EB523069CD8ADB33F78F58 77023ffe214c04ff *82E58A2C08AAFE72C8EB523069CD8ADB33F78F58
DROP TABLE t1; DROP TABLE t1;
End of 5.0 tests End of 5.0 tests
#
# Start of 10.0 tests
#
#
# MDEV-10306 Wrong results with combination of CONCAT, SUBSTR and CONVERT in subquery
#
SET @save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch='derived_merge=on';
CREATE TABLE t1 (t VARCHAR(32) CHARSET latin1);
INSERT INTO t1 VALUES('abcdefghi');
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT ENCRYPT(t,'aa') t2 FROM t1) sub;
c2
aaHHlPHAM4sjs-aaHHlPHAM4sjs
DROP TABLE t1;
SET optimizer_switch=@save_optimizer_switch;
#
# End of 10.0 tests
#

18
mysql-test/r/gis.result
View File

@ -1641,5 +1641,23 @@ AsText(g)
NULL NULL
POINT(1 1) POINT(1 1)
# #
# MDEV-10306 Wrong results with combination of CONCAT, SUBSTR and CONVERT in subquery
#
SET @save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch='derived_merge=on';
CREATE TABLE t1 (x INT, y INT);
INSERT INTO t1 VALUES(0,0);
SELECT LENGTH(t2) c2 FROM (SELECT ST_BUFFER(POINT(x,y), 0) t2 FROM t1) sub;
c2
25
SELECT LENGTH(CONCAT(t2,'-',t2)) c2 FROM (SELECT ST_BUFFER(POINT(x,y), 0) t2 FROM t1) sub;
c2
51
SELECT LENGTH(CONCAT(t2,'--',t2)) c2 FROM (SELECT ST_BUFFER(POINT(x,y), 0) t2 FROM t1) sub;
c2
52
DROP TABLE t1;
SET optimizer_switch=@save_optimizer_switch;
#
# End 10.0 tests # End 10.0 tests
# #

16
mysql-test/t/ctype_ucs.test
View File

@ -923,6 +923,22 @@ SET NAMES utf8, character_set_connection=ucs2;
SELECT 'a','aa'; SELECT 'a','aa';
--echo #
--echo # MDEV-10306 Wrong results with combination of CONCAT, SUBSTR and CONVERT in subquery
--echo #
SET NAMES utf8, character_set_connection=ucs2;
SET @save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch=_utf8'derived_merge=on';
CREATE TABLE t1 (t VARCHAR(10) CHARSET latin1);
INSERT INTO t1 VALUES('abcdefghi');
SET NAMES utf8, character_set_connection=ucs2;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT HEX(t) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT TO_BASE64(t) t2 FROM t1) sub;
DROP TABLE t1;
SET optimizer_switch=@save_optimizer_switch;
--echo # --echo #
--echo # End of 10.0 tests --echo # End of 10.0 tests
--echo # --echo #

91
mysql-test/t/func_concat.test
View File

@ -145,3 +145,94 @@ CALL p1();
DROP PROCEDURE p1; DROP PROCEDURE p1;
--echo # End of 5.1 tests --echo # End of 5.1 tests
--echo #
--echo # Start of 10.0 tests
--echo #
--echo #
--echo # MDEV-10306 Wrong results with combination of CONCAT, SUBSTR and CONVERT in subquery
--echo #
SET @save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch='derived_merge=on';
CREATE TABLE t1 (t VARCHAR(10) CHARSET latin1);
INSERT INTO t1 VALUES('1234567');
SELECT CONCAT(SUBSTR(t2, 1, 3), SUBSTR(t2, 5)) c1,
CONCAT(SUBSTR(t2,1,3),'---',SUBSTR(t2,5)) c2
FROM (SELECT CONVERT(t USING latin1) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT CONVERT(t USING latin1) t2 FROM t1) sub;
DROP TABLE t1;
# Other functions affected by MDEV-10306
CREATE TABLE t1 (t VARCHAR(10) CHARSET latin1);
INSERT INTO t1 VALUES('1234567');
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT CONVERT(t USING latin1) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT REVERSE(t) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT SOUNDEX(t) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT TO_BASE64(t) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT WEIGHT_STRING(t) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT HEX(t) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT QUOTE(t) t2 FROM t1) sub;
DROP TABLE t1;
CREATE TABLE t1 (t VARCHAR(32) CHARSET latin1);
INSERT INTO t1 VALUES(TO_BASE64('abcdefghi'));
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT FROM_BASE64(t) t2 FROM t1) sub;
DROP TABLE t1;
CREATE TABLE t1 (t VARCHAR(32) CHARSET latin1);
INSERT INTO t1 VALUES(HEX('abcdefghi'));
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT UNHEX(t) t2 FROM t1) sub;
DROP TABLE t1;
CREATE TABLE t1 (t VARCHAR(30) CHARSET latin1);
INSERT INTO t1 VALUES('test');
SELECT LENGTH(CONCAT(t2)) c2 FROM (SELECT AES_ENCRYPT(t,'x') t2 FROM t1) sub;
SELECT LENGTH(CONCAT(t2,'-',t2)) c2 FROM (SELECT AES_ENCRYPT(t,'x') t2 FROM t1) sub;
SELECT LENGTH(CONCAT(t2,'--',t2)) c2 FROM (SELECT AES_ENCRYPT(t,'x') t2 FROM t1) sub;
SELECT LENGTH(CONCAT(t2)) c2 FROM (SELECT AES_DECRYPT(AES_ENCRYPT(t,'x'),'x') t2 FROM t1) sub;
SELECT LENGTH(CONCAT(t2,'-',t2)) c2 FROM (SELECT AES_DECRYPT(AES_ENCRYPT(t,'x'),'x') t2 FROM t1) sub;
SELECT LENGTH(CONCAT(t2,'--',t2)) c2 FROM (SELECT AES_DECRYPT(AES_ENCRYPT(t,'x'),'x') t2 FROM t1) sub;
DROP TABLE t1;
# Functions not affected by MDEV-10306
# They only had an unused tmp_value, which was removed.
CREATE TABLE t1 (t VARCHAR(64) CHARSET latin1);
INSERT INTO t1 VALUES('123456789');
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT MD5(t) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT FORMAT(t,2) t2 FROM t1) sub;
DROP TABLE t1;
# Functions not affected by MDEV-10306
# They already use tmp_value only for internal purposes and
# return the result in the String passed to val_str()
CREATE TABLE t1 (t VARCHAR(32) CHARSET latin1);
INSERT INTO t1 VALUES('abcdefghi');
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT INSERT(t,3,4,'xxx') t2 FROM t1) sub;
DROP TABLE t1;
# Functions not affected by MDEV-10306
# They use this code style:
# String *res= args[0]->val_str(str);
# tmp_value.set(*res, start, end);
# return &tmp_value;
CREATE TABLE t1 (t VARCHAR(10) CHARSET latin1);
INSERT INTO t1 VALUES('abcdefghi');
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT LEFT(t,10) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT RIGHT(t,10) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT SUBSTR(t,1,10) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT LTRIM(t) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT RTRIM(t) t2 FROM t1) sub;
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT TRIM(t) t2 FROM t1) sub;
DROP TABLE t1;
SET optimizer_switch=@save_optimizer_switch;

24
mysql-test/t/func_crypt.test
View File

@ -70,3 +70,27 @@ SELECT OLD_PASSWORD(c1), PASSWORD(c1) FROM t1;
DROP TABLE t1; DROP TABLE t1;
--echo End of 5.0 tests --echo End of 5.0 tests
--echo #
--echo # Start of 10.0 tests
--echo #
--echo #
--echo # MDEV-10306 Wrong results with combination of CONCAT, SUBSTR and CONVERT in subquery
--echo #
SET @save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch='derived_merge=on';
# ENCRYPT() is not affected by MDEV-10306
# It already uses tmp_value only for internal purposes and
# returns the result in the String passed to val_str()
CREATE TABLE t1 (t VARCHAR(32) CHARSET latin1);
INSERT INTO t1 VALUES('abcdefghi');
SELECT CONCAT(t2,'-',t2) c2 FROM (SELECT ENCRYPT(t,'aa') t2 FROM t1) sub;
DROP TABLE t1;
SET optimizer_switch=@save_optimizer_switch;
--echo #
--echo # End of 10.0 tests
--echo #

15
mysql-test/t/gis.test
View File

@ -1502,6 +1502,21 @@ DROP VIEW v1;
--echo # --echo #
SELECT AsText(g) FROM (SELECT NULL AS g UNION SELECT Point(1,1)) AS t1; SELECT AsText(g) FROM (SELECT NULL AS g UNION SELECT Point(1,1)) AS t1;
--echo #
--echo # MDEV-10306 Wrong results with combination of CONCAT, SUBSTR and CONVERT in subquery
--echo #
SET @save_optimizer_switch=@@optimizer_switch;
SET optimizer_switch='derived_merge=on';
CREATE TABLE t1 (x INT, y INT);
INSERT INTO t1 VALUES(0,0);
SELECT LENGTH(t2) c2 FROM (SELECT ST_BUFFER(POINT(x,y), 0) t2 FROM t1) sub;
SELECT LENGTH(CONCAT(t2,'-',t2)) c2 FROM (SELECT ST_BUFFER(POINT(x,y), 0) t2 FROM t1) sub;
SELECT LENGTH(CONCAT(t2,'--',t2)) c2 FROM (SELECT ST_BUFFER(POINT(x,y), 0) t2 FROM t1) sub;
DROP TABLE t1;
SET optimizer_switch=@save_optimizer_switch;
--echo # --echo #
--echo # End 10.0 tests --echo # End 10.0 tests
--echo # --echo #

33
sql/item.h
View File

@ -830,25 +830,20 @@ public:
store return value of this method. store return value of this method.
NOTE NOTE
Buffer passed via argument should only be used if the item itself The caller can modify the returned String, if it's not marked
doesn't have an own String buffer. In case when the item maintains "const" (with the String::mark_as_const() method). That means that
it's own string buffer, it's preferable to return it instead to if the item returns its own internal buffer (e.g. tmp_value), it
minimize number of mallocs/memcpys. *must* be marked "const" [1]. So normally it's preferrable to
The caller of this method can modify returned string, but only in case return the result value in the String, that was passed as an
when it was allocated on heap, (is_alloced() is true). This allows argument. But, for example, SUBSTR() returns a String that simply
the caller to efficiently use a buffer allocated by a child without points into the buffer of SUBSTR()'s args[0]->val_str(). Such a
having to allocate a buffer of it's own. The buffer, given to String is always "const", so it's ok to use tmp_value for that and
val_str() as argument, belongs to the caller and is later used by the avoid reallocating/copying of the argument String.
caller at it's own choosing.
A few implications from the above: [1] consider SELECT CONCAT(f, ":", f) FROM (SELECT func() AS f);
- unless you return a string object which only points to your buffer here the return value of f() is used twice in the top-level
but doesn't manages it you should be ready that it will be select, and if they share the same tmp_value buffer, modifying the
modified. first one will implicitly modify the second too.
- even for not allocated strings (is_alloced() == false) the caller
can change charset (see Item_func_{typecast/binary}. XXX: is this
a bug?
- still you should try to minimize data copying and return internal
object whenever possible.
RETURN RETURN
In case of NULL value return 0 (NULL pointer) and set null_value flag In case of NULL value return 0 (NULL pointer) and set null_value flag

2
sql/item_geofunc.cc
View File

@ -1268,7 +1268,7 @@ String *Item_func_buffer::val_str(String *str_value)
{ {
DBUG_ENTER("Item_func_buffer::val_str"); DBUG_ENTER("Item_func_buffer::val_str");
DBUG_ASSERT(fixed == 1); DBUG_ASSERT(fixed == 1);
String *obj= args[0]->val_str(&tmp_value); String *obj= args[0]->val_str(str_value);
double dist= args[1]->val_real(); double dist= args[1]->val_real();
Geometry_buffer buffer; Geometry_buffer buffer;
Geometry *g; Geometry *g;

2
sql/item_geofunc.h
View File

@ -171,7 +171,6 @@ public:
class Item_func_spatial_collection: public Item_geometry_func class Item_func_spatial_collection: public Item_geometry_func
{ {
String tmp_value;
enum Geometry::wkbType coll_type; enum Geometry::wkbType coll_type;
enum Geometry::wkbType item_type; enum Geometry::wkbType item_type;
public: public:
@ -325,7 +324,6 @@ protected:
Gcalc_result_receiver res_receiver; Gcalc_result_receiver res_receiver;
Gcalc_operation_reducer operation; Gcalc_operation_reducer operation;
String tmp_value;
public: public:
Item_func_buffer(Item *obj, Item *distance): Item_func_buffer(Item *obj, Item *distance):

211
sql/item_strfunc.cc
View File

@ -73,8 +73,14 @@ size_t username_char_length= 80;
Conversion happens only in case of "tricky" Item character set (e.g. UCS2). Conversion happens only in case of "tricky" Item character set (e.g. UCS2).
Normally conversion does not happen, and val_str_ascii() is immediately Normally conversion does not happen, and val_str_ascii() is immediately
returned instead. returned instead.
No matter if conversion is needed or not needed,
the result is always returned in "str" (see MDEV-10306 why).
@param [OUT] str - Store the result here
@param [IN] ascii_buffer - Use this temporary buffer to call val_str_ascii()
*/ */
String *Item_func::val_str_from_val_str_ascii(String *str, String *str2) String *Item_func::val_str_from_val_str_ascii(String *str, String *ascii_buffer)
{ {
DBUG_ASSERT(fixed == 1); DBUG_ASSERT(fixed == 1);
@ -86,19 +92,19 @@ String *Item_func::val_str_from_val_str_ascii(String *str, String *str2)
return res; return res;
} }
DBUG_ASSERT(str != str2); DBUG_ASSERT(str != ascii_buffer);
uint errors; uint errors;
String *res= val_str_ascii(str); String *res= val_str_ascii(ascii_buffer);
if (!res) if (!res)
return 0; return 0;
if ((null_value= str2->copy(res->ptr(), res->length(), if ((null_value= str->copy(res->ptr(), res->length(),
&my_charset_latin1, collation.collation, &my_charset_latin1, collation.collation,
&errors))) &errors)))
return 0; return 0;
return str2; return str;
} }
@ -368,12 +374,12 @@ void Item_func_sha2::fix_length_and_dec()
/* Implementation of AES encryption routines */ /* Implementation of AES encryption routines */
String *Item_func_aes_encrypt::val_str(String *str) String *Item_func_aes_encrypt::val_str(String *str2)
{ {
DBUG_ASSERT(fixed == 1); DBUG_ASSERT(fixed == 1);
char key_buff[80]; char key_buff[80];
String tmp_key_value(key_buff, sizeof(key_buff), system_charset_info); String tmp_key_value(key_buff, sizeof(key_buff), system_charset_info);
String *sptr= args[0]->val_str(str); // String to encrypt String *sptr= args[0]->val_str(&str_value); // String to encrypt
String *key= args[1]->val_str(&tmp_key_value); // key String *key= args[1]->val_str(&tmp_key_value); // key
int aes_length; int aes_length;
if (sptr && key) // we need both arguments to be not NULL if (sptr && key) // we need both arguments to be not NULL
@ -381,15 +387,15 @@ String *Item_func_aes_encrypt::val_str(String *str)
null_value=0; null_value=0;
aes_length=my_aes_get_size(sptr->length()); // Calculate result length aes_length=my_aes_get_size(sptr->length()); // Calculate result length
if (!str_value.alloc(aes_length)) // Ensure that memory is free if (!str2->alloc(aes_length)) // Ensure that memory is free
{ {
// finally encrypt directly to allocated buffer. // finally encrypt directly to allocated buffer.
if (my_aes_encrypt(sptr->ptr(),sptr->length(), (char*) str_value.ptr(), if (my_aes_encrypt(sptr->ptr(),sptr->length(), (char*) str2->ptr(),
key->ptr(), key->length()) == aes_length) key->ptr(), key->length()) == aes_length)
{ {
// We got the expected result length // We got the expected result length
str_value.length((uint) aes_length); str2->length((uint) aes_length);
return &str_value; return str2;
} }
} }
} }
@ -412,22 +418,22 @@ String *Item_func_aes_decrypt::val_str(String *str)
String *sptr, *key; String *sptr, *key;
DBUG_ENTER("Item_func_aes_decrypt::val_str"); DBUG_ENTER("Item_func_aes_decrypt::val_str");
sptr= args[0]->val_str(str); // String to decrypt sptr= args[0]->val_str(&str_value); // String to decrypt
key= args[1]->val_str(&tmp_key_value); // Key key= args[1]->val_str(&tmp_key_value); // Key
if (sptr && key) // Need to have both arguments not NULL if (sptr && key) // Need to have both arguments not NULL
{ {
null_value=0; null_value=0;
if (!str_value.alloc(sptr->length())) // Ensure that memory is free if (!str->alloc(sptr->length())) // Ensure that memory is free
{ {
// finally decrypt directly to allocated buffer. // finally decrypt directly to allocated buffer.
int length; int length;
length=my_aes_decrypt(sptr->ptr(), sptr->length(), length=my_aes_decrypt(sptr->ptr(), sptr->length(),
(char*) str_value.ptr(), (char*) str->ptr(),
key->ptr(), key->length()); key->ptr(), key->length());
if (length >= 0) // if we got correct data data if (length >= 0) // if we got correct data data
{ {
str_value.length((uint) length); str->length((uint) length);
DBUG_RETURN(&str_value); DBUG_RETURN(str);
} }
} }
} }
@ -464,7 +470,7 @@ void Item_func_to_base64::fix_length_and_dec()
String *Item_func_to_base64::val_str_ascii(String *str) String *Item_func_to_base64::val_str_ascii(String *str)
{ {
String *res= args[0]->val_str(str); String *res= args[0]->val_str(&tmp_value);
bool too_long= false; bool too_long= false;
int length; int length;
if (!res || if (!res ||
@ -472,7 +478,7 @@ String *Item_func_to_base64::val_str_ascii(String *str)
(too_long= (too_long=
((uint) (length= base64_needed_encoded_length((int) res->length())) > ((uint) (length= base64_needed_encoded_length((int) res->length())) >
current_thd->variables.max_allowed_packet)) || current_thd->variables.max_allowed_packet)) ||
tmp_value.alloc((uint) length)) str->alloc((uint) length))
{ {
null_value= 1; // NULL input, too long input, or OOM. null_value= 1; // NULL input, too long input, or OOM.
if (too_long) if (too_long)
@ -484,11 +490,11 @@ String *Item_func_to_base64::val_str_ascii(String *str)
} }
return 0; return 0;
} }
base64_encode(res->ptr(), (int) res->length(), (char*) tmp_value.ptr()); base64_encode(res->ptr(), (int) res->length(), (char*) str->ptr());
DBUG_ASSERT(length > 0); DBUG_ASSERT(length > 0);
tmp_value.length((uint) length - 1); // Without trailing '\0' str->length((uint) length - 1); // Without trailing '\0'
null_value= 0; null_value= 0;
return &tmp_value; return str;
} }
@ -509,7 +515,7 @@ void Item_func_from_base64::fix_length_and_dec()
String *Item_func_from_base64::val_str(String *str) String *Item_func_from_base64::val_str(String *str)
{ {
String *res= args[0]->val_str_ascii(str); String *res= args[0]->val_str_ascii(&tmp_value);
int length; int length;
const char *end_ptr; const char *end_ptr;
@ -527,11 +533,11 @@ String *Item_func_from_base64::val_str(String *str)
goto err; goto err;
} }
if (tmp_value.alloc((uint) length)) if (str->alloc((uint) length))
goto err; goto err;
if ((length= base64_decode(res->ptr(), (int) res->length(), if ((length= base64_decode(res->ptr(), (int) res->length(),
(char *) tmp_value.ptr(), &end_ptr, 0)) < 0 || (char *) str->ptr(), &end_ptr, 0)) < 0 ||
end_ptr < res->ptr() + res->length()) end_ptr < res->ptr() + res->length())
{ {
push_warning_printf(current_thd, Sql_condition::WARN_LEVEL_WARN, push_warning_printf(current_thd, Sql_condition::WARN_LEVEL_WARN,
@ -540,9 +546,9 @@ String *Item_func_from_base64::val_str(String *str)
goto err; goto err;
} }
tmp_value.length((uint) length); str->length((uint) length);
null_value= 0; null_value= 0;
return &tmp_value; return str;
err: err:
null_value= 1; // NULL input, too long input, OOM, or badly formed input null_value= 1; // NULL input, too long input, OOM, or badly formed input
return 0; return 0;
@ -797,7 +803,7 @@ String *Item_func_des_encrypt::val_str(String *str)
struct st_des_keyschedule keyschedule; struct st_des_keyschedule keyschedule;
const char *append_str="********"; const char *append_str="********";
uint key_number, res_length, tail; uint key_number, res_length, tail;
String *res= args[0]->val_str(str); String *res= args[0]->val_str(&tmp_value);
if ((null_value= args[0]->null_value)) if ((null_value= args[0]->null_value))
return 0; // ENCRYPT(NULL) == NULL return 0; // ENCRYPT(NULL) == NULL
@ -821,7 +827,7 @@ String *Item_func_des_encrypt::val_str(String *str)
} }
else else
{ {
String *keystr=args[1]->val_str(&tmp_value); String *keystr= args[1]->val_str(str);
if (!keystr) if (!keystr)
goto error; goto error;
key_number=127; // User key string key_number=127; // User key string
@ -853,23 +859,23 @@ String *Item_func_des_encrypt::val_str(String *str)
tmp_arg.length(0); tmp_arg.length(0);
tmp_arg.append(res->ptr(), res->length()); tmp_arg.append(res->ptr(), res->length());
code= ER_OUT_OF_RESOURCES; code= ER_OUT_OF_RESOURCES;
if (tmp_arg.append(append_str, tail) || tmp_value.alloc(res_length+1)) if (tmp_arg.append(append_str, tail) || str->alloc(res_length+1))
goto error; goto error;
tmp_arg[res_length-1]=tail; // save extra length tmp_arg[res_length-1]=tail; // save extra length
tmp_value.realloc(res_length+1); str->realloc(res_length+1);
tmp_value.length(res_length+1); str->length(res_length+1);
tmp_value.set_charset(&my_charset_bin); str->set_charset(&my_charset_bin);
tmp_value[0]=(char) (128 | key_number); (*str)[0]=(char) (128 | key_number);
// Real encryption // Real encryption
bzero((char*) &ivec,sizeof(ivec)); bzero((char*) &ivec,sizeof(ivec));
DES_ede3_cbc_encrypt((const uchar*) (tmp_arg.ptr()), DES_ede3_cbc_encrypt((const uchar*) (tmp_arg.ptr()),
(uchar*) (tmp_value.ptr()+1), (uchar*) (str->ptr()+1),
res_length, res_length,
&keyschedule.ks1, &keyschedule.ks1,
&keyschedule.ks2, &keyschedule.ks2,
&keyschedule.ks3, &keyschedule.ks3,
&ivec, TRUE); &ivec, TRUE);
return &tmp_value; return str;
error: error:
push_warning_printf(current_thd,Sql_condition::WARN_LEVEL_WARN, push_warning_printf(current_thd,Sql_condition::WARN_LEVEL_WARN,
@ -893,7 +899,7 @@ String *Item_func_des_decrypt::val_str(String *str)
DES_cblock ivec; DES_cblock ivec;
struct st_des_keyblock keyblock; struct st_des_keyblock keyblock;
struct st_des_keyschedule keyschedule; struct st_des_keyschedule keyschedule;
String *res= args[0]->val_str(str); String *res= args[0]->val_str(&tmp_value);
uint length,tail; uint length,tail;
if ((null_value= args[0]->null_value)) if ((null_value= args[0]->null_value))
@ -917,7 +923,7 @@ String *Item_func_des_decrypt::val_str(String *str)
else else
{ {
// We make good 24-byte (168 bit) key from given plaintext key with MD5 // We make good 24-byte (168 bit) key from given plaintext key with MD5
String *keystr=args[1]->val_str(&tmp_value); String *keystr= args[1]->val_str(str);
if (!keystr) if (!keystr)
goto error; goto error;
@ -932,23 +938,23 @@ String *Item_func_des_decrypt::val_str(String *str)
DES_set_key_unchecked(&keyblock.key3,&keyschedule.ks3); DES_set_key_unchecked(&keyblock.key3,&keyschedule.ks3);
} }
code= ER_OUT_OF_RESOURCES; code= ER_OUT_OF_RESOURCES;
if (tmp_value.alloc(length-1)) if (str->alloc(length-1))
goto error; goto error;
bzero((char*) &ivec,sizeof(ivec)); bzero((char*) &ivec,sizeof(ivec));
DES_ede3_cbc_encrypt((const uchar*) res->ptr()+1, DES_ede3_cbc_encrypt((const uchar*) res->ptr()+1,
(uchar*) (tmp_value.ptr()), (uchar*) (str->ptr()),
length-1, length-1,
&keyschedule.ks1, &keyschedule.ks1,
&keyschedule.ks2, &keyschedule.ks2,
&keyschedule.ks3, &keyschedule.ks3,
&ivec, FALSE); &ivec, FALSE);
/* Restore old length of key */ /* Restore old length of key */
if ((tail=(uint) (uchar) tmp_value[length-2]) > 8) if ((tail=(uint) (uchar) (*str)[length-2]) > 8)
goto wrong_key; // Wrong key goto wrong_key; // Wrong key
tmp_value.length(length-1-tail); str->length(length-1-tail);
tmp_value.set_charset(&my_charset_bin); str->set_charset(&my_charset_bin);
return &tmp_value; return str;
error: error:
push_warning_printf(current_thd,Sql_condition::WARN_LEVEL_WARN, push_warning_printf(current_thd,Sql_condition::WARN_LEVEL_WARN,
@ -1136,25 +1142,26 @@ void Item_func_concat_ws::fix_length_and_dec()
String *Item_func_reverse::val_str(String *str) String *Item_func_reverse::val_str(String *str)
{ {
DBUG_ASSERT(fixed == 1); DBUG_ASSERT(fixed == 1);
String *res = args[0]->val_str(str); String *res= args[0]->val_str(&tmp_value);
char *ptr, *end, *tmp; const char *ptr, *end;
char *tmp;
if ((null_value=args[0]->null_value)) if ((null_value=args[0]->null_value))
return 0; return 0;
/* An empty string is a special case as the string pointer may be null */ /* An empty string is a special case as the string pointer may be null */
if (!res->length()) if (!res->length())
return make_empty_result(); return make_empty_result();
if (tmp_value.alloced_length() < res->length() && if (str->alloced_length() < res->length() &&
tmp_value.realloc(res->length())) str->realloc(res->length()))
{ {
null_value= 1; null_value= 1;
return 0; return 0;
} }
tmp_value.length(res->length()); str->length(res->length());
tmp_value.set_charset(res->charset()); str->set_charset(res->charset());
ptr= (char *) res->ptr(); ptr= res->ptr();
end= ptr + res->length(); end= res->end();
tmp= (char *) tmp_value.ptr() + tmp_value.length(); tmp= (char *) str->end();
#ifdef USE_MB #ifdef USE_MB
if (use_mb(res->charset())) if (use_mb(res->charset()))
{ {
@ -1178,7 +1185,7 @@ String *Item_func_reverse::val_str(String *str)
while (ptr < end) while (ptr < end)
*--tmp= *ptr++; *--tmp= *ptr++;
} }
return &tmp_value; return str;
} }
@ -2446,7 +2453,6 @@ void Item_func_soundex::fix_length_and_dec()
DBUG_ASSERT(collation.collation != NULL); DBUG_ASSERT(collation.collation != NULL);
set_if_bigger(char_length, 4); set_if_bigger(char_length, 4);
fix_char_length(char_length); fix_char_length(char_length);
tmp_value.set_charset(collation.collation);
} }
@ -2491,7 +2497,7 @@ static bool my_uni_isalpha(int wc)
String *Item_func_soundex::val_str(String *str) String *Item_func_soundex::val_str(String *str)
{ {
DBUG_ASSERT(fixed == 1); DBUG_ASSERT(fixed == 1);
String *res =args[0]->val_str(str); String *res= args[0]->val_str(&tmp_value);
char last_ch,ch; char last_ch,ch;
CHARSET_INFO *cs= collation.collation; CHARSET_INFO *cs= collation.collation;
my_wc_t wc; my_wc_t wc;
@ -2501,10 +2507,11 @@ String *Item_func_soundex::val_str(String *str)
if ((null_value= args[0]->null_value)) if ((null_value= args[0]->null_value))
return 0; /* purecov: inspected */ return 0; /* purecov: inspected */
if (tmp_value.alloc(MY_MAX(res->length(), 4 * cs->mbminlen))) if (str->alloc(MY_MAX(res->length(), 4 * cs->mbminlen)))
return str; /* purecov: inspected */ return &tmp_value; /* purecov: inspected */
char *to= (char *) tmp_value.ptr(); str->set_charset(collation.collation);
char *to_end= to + tmp_value.alloced_length(); char *to= (char *) str->ptr();
char *to_end= to + str->alloced_length();
char *from= (char *) res->ptr(), *end= from + res->length(); char *from= (char *) res->ptr(), *end= from + res->length();
for ( ; ; ) /* Skip pre-space */ for ( ; ; ) /* Skip pre-space */
@ -2589,8 +2596,8 @@ String *Item_func_soundex::val_str(String *str)
to+= nbytes; to+= nbytes;
} }
tmp_value.length((uint) (to-tmp_value.ptr())); str->length((uint) (to - str->ptr()));
return &tmp_value; return str;
} }
@ -3399,16 +3406,16 @@ String *Item_func_conv_charset::val_str(String *str)
DBUG_ASSERT(fixed == 1); DBUG_ASSERT(fixed == 1);
if (use_cached_value) if (use_cached_value)
return null_value ? 0 : &str_value; return null_value ? 0 : &str_value;
String *arg= args[0]->val_str(str); String *arg= args[0]->val_str(&tmp_value);
uint dummy_errors; uint dummy_errors;
if (args[0]->null_value) if (args[0]->null_value)
{ {
null_value=1; null_value=1;
return 0; return 0;
} }
null_value= tmp_value.copy(arg->ptr(), arg->length(), arg->charset(), null_value= str->copy(arg->ptr(), arg->length(), arg->charset(),
conv_charset, &dummy_errors); conv_charset, &dummy_errors);
return null_value ? 0 : check_well_formed_result(&tmp_value); return null_value ? 0 : check_well_formed_result(str);
} }
void Item_func_conv_charset::fix_length_and_dec() void Item_func_conv_charset::fix_length_and_dec()
@ -3551,7 +3558,7 @@ String *Item_func_weight_string::val_str(String *str)
DBUG_ASSERT(fixed == 1); DBUG_ASSERT(fixed == 1);
if (args[0]->result_type() != STRING_RESULT || if (args[0]->result_type() != STRING_RESULT ||
!(res= args[0]->val_str(str))) !(res= args[0]->val_str(&tmp_value)))
goto nl; goto nl;
/* /*
@ -3598,19 +3605,19 @@ String *Item_func_weight_string::val_str(String *str)
goto nl; goto nl;
} }
if (tmp_value.alloc(tmp_length)) if (str->alloc(tmp_length))
goto nl; goto nl;
frm_length= cs->coll->strnxfrm(cs, frm_length= cs->coll->strnxfrm(cs,
(uchar *) tmp_value.ptr(), tmp_length, (uchar *) str->ptr(), tmp_length,
nweights ? nweights : tmp_length, nweights ? nweights : tmp_length,
(const uchar *) res->ptr(), res->length(), (const uchar *) res->ptr(), res->length(),
flags); flags);
DBUG_ASSERT(frm_length <= tmp_length); DBUG_ASSERT(frm_length <= tmp_length);
tmp_value.length(frm_length); str->length(frm_length);
null_value= 0; null_value= 0;
return &tmp_value; return str;
nl: nl:
null_value= 1; null_value= 1;
@ -3651,18 +3658,18 @@ String *Item_func_hex::val_str_ascii(String *str)
} }
/* Convert given string to a hex string, character by character */ /* Convert given string to a hex string, character by character */
res= args[0]->val_str(str); res= args[0]->val_str(&tmp_value);
if (!res || tmp_value.alloc(res->length()*2+1)) if (!res || str->alloc(res->length()*2+1))
{ {
null_value=1; null_value=1;
return 0; return 0;
} }
null_value=0; null_value=0;
tmp_value.length(res->length()*2); str->length(res->length()*2);
tmp_value.set_charset(&my_charset_latin1); str->set_charset(&my_charset_latin1);
octet2hex((char*) tmp_value.ptr(), res->ptr(), res->length()); octet2hex((char*) str->ptr(), res->ptr(), res->length());
return &tmp_value; return str;
} }
/** Convert given hex string to a binary string. */ /** Convert given hex string to a binary string. */
@ -3675,8 +3682,8 @@ String *Item_func_unhex::val_str(String *str)
uint length; uint length;
DBUG_ASSERT(fixed == 1); DBUG_ASSERT(fixed == 1);
res= args[0]->val_str(str); res= args[0]->val_str(&tmp_value);
if (!res || tmp_value.alloc(length= (1+res->length())/2)) if (!res || str->alloc(length= (1+res->length())/2))
{ {
null_value=1; null_value=1;
return 0; return 0;
@ -3684,8 +3691,8 @@ String *Item_func_unhex::val_str(String *str)
from= res->ptr(); from= res->ptr();
null_value= 0; null_value= 0;
tmp_value.length(length); str->length(length);
to= (char*) tmp_value.ptr(); to= (char*) str->ptr();
if (res->length() % 2) if (res->length() % 2)
{ {
int hex_char; int hex_char;
@ -3703,7 +3710,7 @@ String *Item_func_unhex::val_str(String *str)
if ((null_value= (hex_char == -1))) if ((null_value= (hex_char == -1)))
return 0; return 0;
} }
return &tmp_value; return str;
} }
@ -3949,7 +3956,7 @@ String *Item_func_quote::val_str(String *str)
ulong max_allowed_packet= current_thd->variables.max_allowed_packet; ulong max_allowed_packet= current_thd->variables.max_allowed_packet;
char *from, *to, *end, *start; char *from, *to, *end, *start;
String *arg= args[0]->val_str(str); String *arg= args[0]->val_str(&tmp_value);
uint arg_length, new_length; uint arg_length, new_length;
if (!arg) // Null argument if (!arg) // Null argument
{ {
@ -3976,7 +3983,7 @@ String *Item_func_quote::val_str(String *str)
set_if_smaller(new_length, max_allowed_packet); set_if_smaller(new_length, max_allowed_packet);
} }
if (tmp_value.alloc(new_length)) if (str->alloc(new_length))
goto null; goto null;
if (collation.collation->mbmaxlen > 1) if (collation.collation->mbmaxlen > 1)
@ -3984,7 +3991,7 @@ String *Item_func_quote::val_str(String *str)
CHARSET_INFO *cs= collation.collation; CHARSET_INFO *cs= collation.collation;
int mblen; int mblen;
uchar *to_end; uchar *to_end;
to= (char*) tmp_value.ptr(); to= (char*) str->ptr();
to_end= (uchar*) to + new_length; to_end= (uchar*) to + new_length;
/* Put leading quote */ /* Put leading quote */
@ -4021,14 +4028,14 @@ String *Item_func_quote::val_str(String *str)
if ((mblen= cs->cset->wc_mb(cs, '\'', (uchar *) to, to_end)) <= 0) if ((mblen= cs->cset->wc_mb(cs, '\'', (uchar *) to, to_end)) <= 0)
goto toolong; goto toolong;
to+= mblen; to+= mblen;
new_length= to - tmp_value.ptr(); new_length= to - str->ptr();
goto ret; goto ret;
} }
/* /*
We replace characters from the end to the beginning We replace characters from the end to the beginning
*/ */
to= (char*) tmp_value.ptr() + new_length - 1; to= (char*) str->ptr() + new_length - 1;
*to--= '\''; *to--= '\'';
for (start= (char*) arg->ptr(),end= start + arg_length; end-- != start; to--) for (start= (char*) arg->ptr(),end= start + arg_length; end-- != start; to--)
{ {
@ -4058,10 +4065,10 @@ String *Item_func_quote::val_str(String *str)
*to= '\''; *to= '\'';
ret: ret:
tmp_value.length(new_length); str->length(new_length);
tmp_value.set_charset(collation.collation); str->set_charset(collation.collation);
null_value= 0; null_value= 0;
return &tmp_value; return str;
toolong: toolong:
push_warning_printf(current_thd, Sql_condition::WARN_LEVEL_WARN, push_warning_printf(current_thd, Sql_condition::WARN_LEVEL_WARN,
@ -4134,7 +4141,7 @@ String *Item_func_compress::val_str(String *str)
char *tmp, *last_char; char *tmp, *last_char;
DBUG_ASSERT(fixed == 1); DBUG_ASSERT(fixed == 1);
if (!(res= args[0]->val_str(str))) if (!(res= args[0]->val_str(&tmp_value)))
{ {
null_value= 1; null_value= 1;
return 0; return 0;
@ -4155,13 +4162,13 @@ String *Item_func_compress::val_str(String *str)
// Check new_size overflow: new_size <= res->length() // Check new_size overflow: new_size <= res->length()
if (((uint32) (new_size+5) <= res->length()) || if (((uint32) (new_size+5) <= res->length()) ||
buffer.realloc((uint32) new_size + 4 + 1)) str->realloc((uint32) new_size + 4 + 1))
{ {
null_value= 1; null_value= 1;
return 0; return 0;
} }
body= ((Byte*)buffer.ptr()) + 4; body= ((Byte*)str->ptr()) + 4;
// As far as we have checked res->is_empty() we can use ptr() // As far as we have checked res->is_empty() we can use ptr()
if ((err= my_compress_buffer(body, &new_size, (const uchar *)res->ptr(), if ((err= my_compress_buffer(body, &new_size, (const uchar *)res->ptr(),
@ -4173,7 +4180,7 @@ String *Item_func_compress::val_str(String *str)
return 0; return 0;
} }
tmp= (char*)buffer.ptr(); // int4store is a macro; avoid side effects tmp= (char*) str->ptr(); // int4store is a macro; avoid side effects
int4store(tmp, res->length() & 0x3FFFFFFF); int4store(tmp, res->length() & 0x3FFFFFFF);
/* This is to ensure that things works for CHAR fields, which trim ' ': */ /* This is to ensure that things works for CHAR fields, which trim ' ': */
@ -4184,15 +4191,15 @@ String *Item_func_compress::val_str(String *str)
new_size++; new_size++;
} }
buffer.length((uint32)new_size + 4); str->length((uint32)new_size + 4);
return &buffer; return str;
} }
String *Item_func_uncompress::val_str(String *str) String *Item_func_uncompress::val_str(String *str)
{ {
DBUG_ASSERT(fixed == 1); DBUG_ASSERT(fixed == 1);
String *res= args[0]->val_str(str); String *res= args[0]->val_str(&tmp_value);
ulong new_size; ulong new_size;
int err; int err;
uint code; uint code;
@ -4223,14 +4230,14 @@ String *Item_func_uncompress::val_str(String *str)
max_allowed_packet)); max_allowed_packet));
goto err; goto err;
} }
if (buffer.realloc((uint32)new_size)) if (str->realloc((uint32)new_size))
goto err; goto err;
if ((err= uncompress((Byte*)buffer.ptr(), &new_size, if ((err= uncompress((Byte*)str->ptr(), &new_size,
((const Bytef*)res->ptr())+4,res->length()-4)) == Z_OK) ((const Bytef*)res->ptr())+4,res->length()-4)) == Z_OK)
{ {
buffer.length((uint32) new_size); str->length((uint32) new_size);
return &buffer; return str;
} }
code= ((err == Z_BUF_ERROR) ? ER_ZLIB_Z_BUF_ERROR : code= ((err == Z_BUF_ERROR) ? ER_ZLIB_Z_BUF_ERROR :

8
sql/item_strfunc.h
View File

@ -87,7 +87,6 @@ public:
class Item_func_md5 :public Item_str_ascii_func class Item_func_md5 :public Item_str_ascii_func
{ {
String tmp_value;
public: public:
Item_func_md5(Item *a) :Item_str_ascii_func(a) {} Item_func_md5(Item *a) :Item_str_ascii_func(a) {}
String *val_str_ascii(String *); String *val_str_ascii(String *);
@ -167,7 +166,6 @@ public:
class Item_func_decode_histogram :public Item_str_func class Item_func_decode_histogram :public Item_str_func
{ {
String tmp_value;
public: public:
Item_func_decode_histogram(Item *a, Item *b) Item_func_decode_histogram(Item *a, Item *b)
:Item_str_func(a, b) {} :Item_str_func(a, b) {}
@ -675,7 +673,6 @@ public:
class Item_func_format :public Item_str_ascii_func class Item_func_format :public Item_str_ascii_func
{ {
String tmp_str;
MY_LOCALE *locale; MY_LOCALE *locale;
public: public:
Item_func_format(Item *org, Item *dec): Item_str_ascii_func(org, dec) {} Item_func_format(Item *org, Item *dec): Item_str_ascii_func(org, dec) {}
@ -729,7 +726,6 @@ public:
class Item_func_binlog_gtid_pos :public Item_str_func class Item_func_binlog_gtid_pos :public Item_str_func
{ {
String tmp_value;
public: public:
Item_func_binlog_gtid_pos(Item *arg1,Item *arg2) :Item_str_func(arg1,arg2) {} Item_func_binlog_gtid_pos(Item *arg1,Item *arg2) :Item_str_func(arg1,arg2) {}
String *val_str(String *); String *val_str(String *);
@ -1106,7 +1102,7 @@ public:
class Item_func_compress: public Item_str_func class Item_func_compress: public Item_str_func
{ {
String buffer; String tmp_value;
public: public:
Item_func_compress(Item *a):Item_str_func(a){} Item_func_compress(Item *a):Item_str_func(a){}
void fix_length_and_dec(){max_length= (args[0]->max_length*120)/100+12;} void fix_length_and_dec(){max_length= (args[0]->max_length*120)/100+12;}
@ -1116,7 +1112,7 @@ public:
class Item_func_uncompress: public Item_str_func class Item_func_uncompress: public Item_str_func
{ {
String buffer; String tmp_value;
public: public:
Item_func_uncompress(Item *a): Item_str_func(a){} Item_func_uncompress(Item *a): Item_str_func(a){}
void fix_length_and_dec(){ maybe_null= 1; max_length= MAX_BLOB_WIDTH; } void fix_length_and_dec(){ maybe_null= 1; max_length= MAX_BLOB_WIDTH; }