flush tables;
drop table if exists `m1`,`t1`;
create table `t1`(`c1` int)engine=myisam;
create table `m1`(`c1` int)engine=merge union=(`t1`);
alter table `m1` add index `idx_c1`(`c1`);
alter table `m1`union=(`t1`);
alter table `t1` add index `idx_c1`(`c1`);
alter table `m1` add index `idx_c1`(`c1`);


090611  4:55:21 [Note] ./bin/mysqld: ready for connections.
Version: '5.1.37-debug'  socket: '/tmp/mysql.sock'  port: 3306  yes
==28038== Thread 3:
==28038== Invalid write of size 1
==28038==    at 0x4006594: memset (mc_replace_strmem.c:479)
==28038==    by 0x84E5B0B: myrg_attach_children (myrg_open.c:433)
==28038==    by 0x84E4E64: ha_myisammrg::attach_children() (ha_myisammrg.cc:546)
==28038==    by 0x84E5234: ha_myisammrg::extra(ha_extra_function) (ha_myisammrg.cc:944)
==28038==    by 0x8247766: attach_merge_children(TABLE_LIST*) (sql_base.cc:4147)
==28038==    by 0x8253C62: open_tables(THD*, TABLE_LIST**, unsigned*, unsigned) (sql_base.cc:4709)
==28038==    by 0x8253FAC: open_and_lock_tables_derived(THD*, TABLE_LIST*, bool) (sql_base.cc:4977)
==28038==    by 0x8254192: open_n_lock_single_table(THD*, TABLE_LIST*, thr_lock_type) (mysql_priv.h:1550)
==28038==    by 0x8320361: mysql_alter_table(THD*, char*, char*, st_ha_create_information*, TABLE_LIST*, Alter_info*, unsigned, st_order*, bool) (sql_table.cc:6428)
==28038==    by 0x82109F2: mysql_execute_command(THD*) (sql_parse.cc:2860)
==28038==    by 0x82115DC: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5933)
==28038==    by 0x82128FB: dispatch_command(enum_server_command, THD*, char*, unsigned) (sql_parse.cc:1213)
==28038==  Address 0x4108961 is 0 bytes after a block of size 1 alloc'd
==28038==    at 0x4005400: malloc (vg_replace_malloc.c:149)
==28038==    by 0x84F6587: my_malloc (my_malloc.c:34)
==28038==    by 0x84E5ADC: myrg_attach_children (myrg_open.c:428)
==28038==    by 0x84E4E64: ha_myisammrg::attach_children() (ha_myisammrg.cc:546)
==28038==    by 0x84E5234: ha_myisammrg::extra(ha_extra_function) (ha_myisammrg.cc:944)
==28038==    by 0x8247766: attach_merge_children(TABLE_LIST*) (sql_base.cc:4147)
==28038==    by 0x8253C62: open_tables(THD*, TABLE_LIST**, unsigned*, unsigned) (sql_base.cc:4709)
==28038==    by 0x8253FAC: open_and_lock_tables_derived(THD*, TABLE_LIST*, bool) (sql_base.cc:4977)
==28038==    by 0x8254192: open_n_lock_single_table(THD*, TABLE_LIST*, thr_lock_type) (mysql_priv.h:1550)
==28038==    by 0x8320361: mysql_alter_table(THD*, char*, char*, st_ha_create_information*, TABLE_LIST*, Alter_info*, unsigned, st_order*, bool) (sql_table.cc:6428)
==28038==    by 0x82109F2: mysql_execute_command(THD*) (sql_parse.cc:2860)
==28038==    by 0x82115DC: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5933)
==28038== 
==28038== ---- Attach to debugger ? --- [Return/N/n/Y/y/C/c] ---- c
==28038== 
==28038== Invalid write of size 1
==28038==    at 0x400659C: memset (mc_replace_strmem.c:479)
==28038==    by 0x84E5B0B: myrg_attach_children (myrg_open.c:433)
==28038==    by 0x84E4E64: ha_myisammrg::attach_children() (ha_myisammrg.cc:546)
==28038==    by 0x84E5234: ha_myisammrg::extra(ha_extra_function) (ha_myisammrg.cc:944)
==28038==    by 0x8247766: attach_merge_children(TABLE_LIST*) (sql_base.cc:4147)
==28038==    by 0x8253C62: open_tables(THD*, TABLE_LIST**, unsigned*, unsigned) (sql_base.cc:4709)
==28038==    by 0x8253FAC: open_and_lock_tables_derived(THD*, TABLE_LIST*, bool) (sql_base.cc:4977)
==28038==    by 0x8254192: open_n_lock_single_table(THD*, TABLE_LIST*, thr_lock_type) (mysql_priv.h:1550)
==28038==    by 0x8320361: mysql_alter_table(THD*, char*, char*, st_ha_create_information*, TABLE_LIST*, Alter_info*, unsigned, st_order*, bool) (sql_table.cc:6428)
==28038==    by 0x82109F2: mysql_execute_command(THD*) (sql_parse.cc:2860)
==28038==    by 0x82115DC: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5933)
==28038==    by 0x82128FB: dispatch_command(enum_server_command, THD*, char*, unsigned) (sql_parse.cc:1213)
==28038==  Address 0x4108962 is 1 bytes after a block of size 1 alloc'd
==28038==    at 0x4005400: malloc (vg_replace_malloc.c:149)
==28038==    by 0x84F6587: my_malloc (my_malloc.c:34)
==28038==    by 0x84E5ADC: myrg_attach_children (myrg_open.c:428)
==28038==    by 0x84E4E64: ha_myisammrg::attach_children() (ha_myisammrg.cc:546)
==28038==    by 0x84E5234: ha_myisammrg::extra(ha_extra_function) (ha_myisammrg.cc:944)
==28038==    by 0x8247766: attach_merge_children(TABLE_LIST*) (sql_base.cc:4147)
==28038==    by 0x8253C62: open_tables(THD*, TABLE_LIST**, unsigned*, unsigned) (sql_base.cc:4709)
==28038==    by 0x8253FAC: open_and_lock_tables_derived(THD*, TABLE_LIST*, bool) (sql_base.cc:4977)
==28038==    by 0x8254192: open_n_lock_single_table(THD*, TABLE_LIST*, thr_lock_type) (mysql_priv.h:1550)
==28038==    by 0x8320361: mysql_alter_table(THD*, char*, char*, st_ha_create_information*, TABLE_LIST*, Alter_info*, unsigned, st_order*, bool) (sql_table.cc:6428)
==28038==    by 0x82109F2: mysql_execute_command(THD*) (sql_parse.cc:2860)
==28038==    by 0x82115DC: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5933)
==28038== 
==28038== Invalid read of size 4
==28038==    at 0x84E5C00: myrg_attach_children (myrg_open.c:463)
==28038==    by 0x84E4E64: ha_myisammrg::attach_children() (ha_myisammrg.cc:546)
==28038==    by 0x84E5234: ha_myisammrg::extra(ha_extra_function) (ha_myisammrg.cc:944)
==28038==    by 0x8247766: attach_merge_children(TABLE_LIST*) (sql_base.cc:4147)
==28038==    by 0x8253C62: open_tables(THD*, TABLE_LIST**, unsigned*, unsigned) (sql_base.cc:4709)
==28038==    by 0x8253FAC: open_and_lock_tables_derived(THD*, TABLE_LIST*, bool) (sql_base.cc:4977)
==28038==    by 0x8254192: open_n_lock_single_table(THD*, TABLE_LIST*, thr_lock_type) (mysql_priv.h:1550)
==28038==    by 0x8320361: mysql_alter_table(THD*, char*, char*, st_ha_create_information*, TABLE_LIST*, Alter_info*, unsigned, st_order*, bool) (sql_table.cc:6428)
==28038==    by 0x82109F2: mysql_execute_command(THD*) (sql_parse.cc:2860)
==28038==    by 0x82115DC: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5933)
==28038==    by 0x82128FB: dispatch_command(enum_server_command, THD*, char*, unsigned) (sql_parse.cc:1213)
==28038==    by 0x82139C8: do_command(THD*) (sql_parse.cc:854)
==28038==  Address 0x4108960 is 0 bytes inside a block of size 1 alloc'd
==28038==    at 0x4005400: malloc (vg_replace_malloc.c:149)
==28038==    by 0x84F6587: my_malloc (my_malloc.c:34)
==28038==    by 0x84E5ADC: myrg_attach_children (myrg_open.c:428)
==28038==    by 0x84E4E64: ha_myisammrg::attach_children() (ha_myisammrg.cc:546)
==28038==    by 0x84E5234: ha_myisammrg::extra(ha_extra_function) (ha_myisammrg.cc:944)
==28038==    by 0x8247766: attach_merge_children(TABLE_LIST*) (sql_base.cc:4147)
==28038==    by 0x8253C62: open_tables(THD*, TABLE_LIST**, unsigned*, unsigned) (sql_base.cc:4709)
==28038==    by 0x8253FAC: open_and_lock_tables_derived(THD*, TABLE_LIST*, bool) (sql_base.cc:4977)
==28038==    by 0x8254192: open_n_lock_single_table(THD*, TABLE_LIST*, thr_lock_type) (mysql_priv.h:1550)
==28038==    by 0x8320361: mysql_alter_table(THD*, char*, char*, st_ha_create_information*, TABLE_LIST*, Alter_info*, unsigned, st_order*, bool) (sql_table.cc:6428)
==28038==    by 0x82109F2: mysql_execute_command(THD*) (sql_parse.cc:2860)
==28038==    by 0x82115DC: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5933)
==28038== 
==28038== Invalid read of size 1
==28038==    at 0x4006D8D: memcpy (mc_replace_strmem.c:406)
==28038==    by 0x84E3538: ha_myisammrg::info(unsigned) (ha_myisammrg.cc:933)
==28038==    by 0x84E4F39: ha_myisammrg::attach_children() (ha_myisammrg.cc:558)
==28038==    by 0x84E5234: ha_myisammrg::extra(ha_extra_function) (ha_myisammrg.cc:944)
==28038==    by 0x8247766: attach_merge_children(TABLE_LIST*) (sql_base.cc:4147)
==28038==    by 0x8253C62: open_tables(THD*, TABLE_LIST**, unsigned*, unsigned) (sql_base.cc:4709)
==28038==    by 0x8253FAC: open_and_lock_tables_derived(THD*, TABLE_LIST*, bool) (sql_base.cc:4977)
==28038==    by 0x8254192: open_n_lock_single_table(THD*, TABLE_LIST*, thr_lock_type) (mysql_priv.h:1550)
==28038==    by 0x8320361: mysql_alter_table(THD*, char*, char*, st_ha_create_information*, TABLE_LIST*, Alter_info*, unsigned, st_order*, bool) (sql_table.cc:6428)
==28038==    by 0x82109F2: mysql_execute_command(THD*) (sql_parse.cc:2860)
==28038==    by 0x82115DC: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5933)
==28038==    by 0x82128FB: dispatch_command(enum_server_command, THD*, char*, unsigned) (sql_parse.cc:1213)
==28038==  Address 0x4108961 is 0 bytes after a block of size 1 alloc'd
==28038==    at 0x4005400: malloc (vg_replace_malloc.c:149)
==28038==    by 0x84F6587: my_malloc (my_malloc.c:34)
==28038==    by 0x84E5ADC: myrg_attach_children (myrg_open.c:428)
==28038==    by 0x84E4E64: ha_myisammrg::attach_children() (ha_myisammrg.cc:546)
==28038==    by 0x84E5234: ha_myisammrg::extra(ha_extra_function) (ha_myisammrg.cc:944)
==28038==    by 0x8247766: attach_merge_children(TABLE_LIST*) (sql_base.cc:4147)
==28038==    by 0x8253C62: open_tables(THD*, TABLE_LIST**, unsigned*, unsigned) (sql_base.cc:4709)
==28038==    by 0x8253FAC: open_and_lock_tables_derived(THD*, TABLE_LIST*, bool) (sql_base.cc:4977)
==28038==    by 0x8254192: open_n_lock_single_table(THD*, TABLE_LIST*, thr_lock_type) (mysql_priv.h:1550)
==28038==    by 0x8320361: mysql_alter_table(THD*, char*, char*, st_ha_create_information*, TABLE_LIST*, Alter_info*, unsigned, st_order*, bool) (sql_table.cc:6428)
==28038==    by 0x82109F2: mysql_execute_command(THD*) (sql_parse.cc:2860)
==28038==    by 0x82115DC: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5933)
==28038== 
==28038== Invalid read of size 1
==28038==    at 0x4006D96: memcpy (mc_replace_strmem.c:406)
==28038==    by 0x84E3538: ha_myisammrg::info(unsigned) (ha_myisammrg.cc:933)
==28038==    by 0x84E4F39: ha_myisammrg::attach_children() (ha_myisammrg.cc:558)
==28038==    by 0x84E5234: ha_myisammrg::extra(ha_extra_function) (ha_myisammrg.cc:944)
==28038==    by 0x8247766: attach_merge_children(TABLE_LIST*) (sql_base.cc:4147)
==28038==    by 0x8253C62: open_tables(THD*, TABLE_LIST**, unsigned*, unsigned) (sql_base.cc:4709)
==28038==    by 0x8253FAC: open_and_lock_tables_derived(THD*, TABLE_LIST*, bool) (sql_base.cc:4977)
==28038==    by 0x8254192: open_n_lock_single_table(THD*, TABLE_LIST*, thr_lock_type) (mysql_priv.h:1550)
==28038==    by 0x8320361: mysql_alter_table(THD*, char*, char*, st_ha_create_information*, TABLE_LIST*, Alter_info*, unsigned, st_order*, bool) (sql_table.cc:6428)
==28038==    by 0x82109F2: mysql_execute_command(THD*) (sql_parse.cc:2860)
==28038==    by 0x82115DC: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5933)
==28038==    by 0x82128FB: dispatch_command(enum_server_command, THD*, char*, unsigned) (sql_parse.cc:1213)
==28038==  Address 0x4108962 is 1 bytes after a block of size 1 alloc'd
==28038==    at 0x4005400: malloc (vg_replace_malloc.c:149)
==28038==    by 0x84F6587: my_malloc (my_malloc.c:34)
==28038==    by 0x84E5ADC: myrg_attach_children (myrg_open.c:428)
==28038==    by 0x84E4E64: ha_myisammrg::attach_children() (ha_myisammrg.cc:546)
==28038==    by 0x84E5234: ha_myisammrg::extra(ha_extra_function) (ha_myisammrg.cc:944)
==28038==    by 0x8247766: attach_merge_children(TABLE_LIST*) (sql_base.cc:4147)
==28038==    by 0x8253C62: open_tables(THD*, TABLE_LIST**, unsigned*, unsigned) (sql_base.cc:4709)
==28038==    by 0x8253FAC: open_and_lock_tables_derived(THD*, TABLE_LIST*, bool) (sql_base.cc:4977)
==28038==    by 0x8254192: open_n_lock_single_table(THD*, TABLE_LIST*, thr_lock_type) (mysql_priv.h:1550)
==28038==    by 0x8320361: mysql_alter_table(THD*, char*, char*, st_ha_create_information*, TABLE_LIST*, Alter_info*, unsigned, st_order*, bool) (sql_table.cc:6428)
==28038==    by 0x82109F2: mysql_execute_command(THD*) (sql_parse.cc:2860)
==28038==    by 0x82115DC: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5933)
==28038== 
==28038== Invalid read of size 1
==28038==    at 0x4006D9F: memcpy (mc_replace_strmem.c:406)
==28038==    by 0x84E3538: ha_myisammrg::info(unsigned) (ha_myisammrg.cc:933)
==28038==    by 0x84E4F39: ha_myisammrg::attach_children() (ha_myisammrg.cc:558)
==28038==    by 0x84E5234: ha_myisammrg::extra(ha_extra_function) (ha_myisammrg.cc:944)
==28038==    by 0x8247766: attach_merge_children(TABLE_LIST*) (sql_base.cc:4147)
==28038==    by 0x8253C62: open_tables(THD*, TABLE_LIST**, unsigned*, unsigned) (sql_base.cc:4709)
==28038==    by 0x8253FAC: open_and_lock_tables_derived(THD*, TABLE_LIST*, bool) (sql_base.cc:4977)
==28038==    by 0x8254192: open_n_lock_single_table(THD*, TABLE_LIST*, thr_lock_type) (mysql_priv.h:1550)
==28038==    by 0x8320361: mysql_alter_table(THD*, char*, char*, st_ha_create_information*, TABLE_LIST*, Alter_info*, unsigned, st_order*, bool) (sql_table.cc:6428)
==28038==    by 0x82109F2: mysql_execute_command(THD*) (sql_parse.cc:2860)
==28038==    by 0x82115DC: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5933)
==28038==    by 0x82128FB: dispatch_command(enum_server_command, THD*, char*, unsigned) (sql_parse.cc:1213)
==28038==  Address 0x4108963 is 2 bytes after a block of size 1 alloc'd
==28038==    at 0x4005400: malloc (vg_replace_malloc.c:149)
==28038==    by 0x84F6587: my_malloc (my_malloc.c:34)
==28038==    by 0x84E5ADC: myrg_attach_children (myrg_open.c:428)
==28038==    by 0x84E4E64: ha_myisammrg::attach_children() (ha_myisammrg.cc:546)
==28038==    by 0x84E5234: ha_myisammrg::extra(ha_extra_function) (ha_myisammrg.cc:944)
==28038==    by 0x8247766: attach_merge_children(TABLE_LIST*) (sql_base.cc:4147)
==28038==    by 0x8253C62: open_tables(THD*, TABLE_LIST**, unsigned*, unsigned) (sql_base.cc:4709)
==28038==    by 0x8253FAC: open_and_lock_tables_derived(THD*, TABLE_LIST*, bool) (sql_base.cc:4977)
==28038==    by 0x8254192: open_n_lock_single_table(THD*, TABLE_LIST*, thr_lock_type) (mysql_priv.h:1550)
==28038==    by 0x8320361: mysql_alter_table(THD*, char*, char*, st_ha_create_information*, TABLE_LIST*, Alter_info*, unsigned, st_order*, bool) (sql_table.cc:6428)
==28038==    by 0x82109F2: mysql_execute_command(THD*) (sql_parse.cc:2860)
==28038==    by 0x82115DC: mysql_parse(THD*, char const*, unsigned, char const**) (sql_parse.cc:5933)