If we have lower_case_table_names == 2 (usually on case insensitive file
systems) we sometimes make 'homedir' part of the path sent to the
handler into lowercase. So in this case HEAP engine couldn't properly
find and remove HP_SHARE, what caused the bug.
While executing ALTER TABLE ... PARTITION the server uses
a temporary "shadow" table to create the updated table.
This shadow table then gets renamed as the original table.
The shadow table was not prefixed with the special prefix that
marks temporary tables so it was picked up by SHOW TABLE STATUS.
Fixed by isolating the code to create the shadow table name in a
separate function and prefixing the shadow table name with the
special prefix to exclude it from the list of user tables.
See bug 18775 and WL1324 for details.
The value of "low-priority-updates" option and the LOW PRIORITY
prefix was taken into account at parse time.
This caused triggers (among others) to ignore this flag (if
supplied for the DML statement).
Moved reading of the LOW_PRIORITY flag at run time.
Fixed an incosistency when handling
SET GLOBAL LOW_PRIORITY_UPDATES : now it is in effect for
delayed INSERTs.
Tested by checking the effect of LOW_PRIORITY flag via a
trigger.
This is an additional fix.
Item::val_xxx methods are supposed to use original data source and
Item::val_xxx_result methods to use the item's result field. But for the
Item_func_set_user_var class val_xxx_result methods were mapped to val_xxx
methods. This leads, in particular, to producing bad sort keys and thus
wrong order of the result set of queries with group by/order by clauses.
The set of val_xxx_result methods is added to the Item_func_set_user_var
class. It's the same as the val_xxx set of method but uses the result_field
to return a value.
using a derived table over a grouping subselect.
This crash happens only when materialization of the derived tables
requires creation of auxiliary temporary table, for example when
a grouping operation is carried out with usage of a temporary table.
The crash happened because EXPLAIN EXTENDED when printing the query
expression made an attempt to use the objects created in the mem_root
of the temporary table which has been already freed by the moment
when printing is called.
This bug appeared after the method Item_field::print() had been
introduced.
To avoid unnecessary work the mysql_alter_table function takes the
list of table fields and applies all changes to it (drops/moves/renames/etc).
Then this function compares the new list and the old one. If the changes
require only .frm to be modified then the actual data isn't copied. To detect
changes all columns attributes but names are compared. When a column has been
moved and has replaced another column with the same attributes except name
the mysql_alter_table function wrongly decides that two fields has been just
renamed. As a result the data from the moved column and from all columns
after it is not copied.
Now the mysql_alter_table function forces table data copying by setting
the need_copy_table flag when it finds a moved column. The flag is set at
the stage when the modified fields are created.
The bug was repeated on MyISAM tables, so isn't InnoDB specific.
Reason of the bug is that partition-related members of TABLE_SHARE
wasn't properly updated after ALTER command. So if other thread doesn't
reread frm file, and just uses cached SHARE, it uses wrong data
