LP:585688 - maridb crashes in federatedx code

Version: MariaDB-server-5.1.44-75.el5.x86_64
One federated table existed.
It happened again today after the federated had been removed, but some new ones had been created.

100525 11:41:56 [Note] /usr/sbin/mysqld: ready for connections.
Version: '5.1.44-MariaDB-mariadb75-log' socket: '/var/lib/mysql/mysql.sock' port: 3306 (MariaDB - http://mariadb.com/)
100525 11:41:56 [Note] Slave I/O thread: connected to master 'replication@10.72.15.21:3306',replication started in log 'mysql-bin.000004' at position 638859063
100525 12:52:33 - mysqld got signal 11 ;
This could be because you hit a bug. It is also possible that this binary
or one of the libraries it was linked against is corrupt, improperly built,
or misconfigured. This error can also be caused by malfunctioning hardware.
We will try our best to scrape up some info that will hopefully help diagnose
the problem, but since we have already crashed, something is definitely wrong
and this may fail.

key_buffer_size=402653184
read_buffer_size=2097152
max_used_connections=23
max_threads=153
threads_connected=5
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 1021479 K
bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

thd: 0x993de40
Attempting backtrace. You can use the following information to find out
where mysqld died. If you see no messages after this, something went
terribly wrong...
stack_bottom = 0x414b5110 thread_stack 0x48000
/usr/sbin/mysqld(my_print_stacktrace+0x35)[0x955135]
/usr/sbin/mysqld(handle_segfault+0x32f)[0x5df10f]
/lib64/libpthread.so.0[0x323d80e930]
/lib64/libpthread.so.0(pthread_mutex_lock+0x0)[0x323d808ac0]
/usr/sbin/mysqld(_ZN14federatedx_txn12release_scanEv+0x67)[0x794247]
/usr/sbin/mysqld(_ZN13ha_federatedx4infoEj+0x83)[0x78f2c3]
/usr/sbin/mysqld[0x6e818c]
/usr/sbin/mysqld(_Z14get_all_tablesP3THDP10TABLE_LISTP4Item+0x8a1)[0x6eb911]
/usr/sbin/mysqld(_Z24get_schema_tables_resultP4JOIN23enum_schema_table_state+0x1d1)[0x6e41b1]
/usr/sbin/mysqld(_ZN4JOIN4execEv+0x400)[0x65ba10]
/usr/sbin/mysqld(_Z12mysql_selectP3THDPPP4ItemP10TABLE_LISTjR4ListIS1_ES2_jP8st_orderSB_S2_SB_yP13select_resultP18st_select_lex_unitP13st_select_lex+0x14e)[0x65da6e]
/usr/sbin/mysqld(_Z13handle_selectP3THDP6st_lexP13select_resultm+0x167)[0x65e367]
/usr/sbin/mysqld[0x5eb5c0]
/usr/sbin/mysqld(_Z21mysql_execute_commandP3THD+0x739)[0x5ee999]
/usr/sbin/mysqld(Z11mysql_parseP3THDPKcjPS2+0x1e5)[0x5f3f85]
/usr/sbin/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x9e6)[0x5f4986]
/usr/sbin/mysqld(_Z10do_commandP3THD+0xe6)[0x5f5576]
/usr/sbin/mysqld(handle_one_connection+0x9e)[0x5e7bce]
/lib64/libpthread.so.0[0x323d806617]
/lib64/libc.so.6(clone+0x6d)[0x3f990d3c2d]
Trying to get some variables.
Some pointers may be invalid and cause the dump to abort...
thd->query at 0x2aaacd14a078 is an invalid pointer
thd->thread_id=9251
thd->killed=NOT_KILLED
The manual page at http://dev.mysql.com/doc/mysql/en/crashing.html contains
information that should help you find out what is causing the crash.