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Fix for bug #30885: MEMORY returns incorrect data if BTREE index is used for NULL lookup

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Problem: creating an rb-tree key we store length (2 bytes) before the actual data for 
varchar key parts. The fact was missed for NULL key parts, when we set NULL byte and 
skip the rest.

Fix: take into account the length of the varchar key parts for NULLs.
This commit is contained in:
ramil/ram@mysql.com/ramil.myoffice.izhnet.ru
2007-10-05 16:33:15 +05:00
parent 1ba3f4f56b
commit b4b7cf2a95
3 changed files with 23 additions and 0 deletions
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6
heap/hp_hash.c
View File

@ -808,6 +808,12 @@ uint hp_rb_pack_key(HP_KEYDEF *keydef, uchar *key, const uchar *old,
if (!(*key++= (char) 1 - *old++)) if (!(*key++= (char) 1 - *old++))
{ {
k_len-= seg->length; k_len-= seg->length;
/*
Take into account length (2 bytes) of varchar key parts
stored before the data.
*/
if (seg->flag & (HA_VAR_LENGTH_PART | HA_BLOB_PART))
k_len-= 2;
continue; continue;
} }
} }

8
mysql-test/r/heap_btree.result
View File

@ -321,4 +321,12 @@ DROP TABLE t1;
CREATE TABLE t1 (a INT, UNIQUE USING BTREE(a)) ENGINE=MEMORY; CREATE TABLE t1 (a INT, UNIQUE USING BTREE(a)) ENGINE=MEMORY;
INSERT INTO t1 VALUES(NULL),(NULL); INSERT INTO t1 VALUES(NULL),(NULL);
DROP TABLE t1; DROP TABLE t1;
create table t1(a varchar(255), b varchar(255),
key using btree (a,b)) engine=memory;
insert into t1 values (1, 1), (3, 3), (2, 2), (NULL, 1), (NULL, NULL), (0, 0);
select * from t1 where a is null;
a b
NULL NULL
NULL 1
drop table t1;
End of 5.0 tests End of 5.0 tests

9
mysql-test/t/heap_btree.test
View File

@ -235,5 +235,14 @@ CREATE TABLE t1 (a INT, UNIQUE USING BTREE(a)) ENGINE=MEMORY;
INSERT INTO t1 VALUES(NULL),(NULL); INSERT INTO t1 VALUES(NULL),(NULL);
DROP TABLE t1; DROP TABLE t1;
#
# Bug #30885: MEMORY returns incorrect data if BTREE index is used for NULL lookup
#
create table t1(a varchar(255), b varchar(255),
key using btree (a,b)) engine=memory;
insert into t1 values (1, 1), (3, 3), (2, 2), (NULL, 1), (NULL, NULL), (0, 0);
select * from t1 where a is null;
drop table t1;
--echo End of 5.0 tests --echo End of 5.0 tests