Use of INNODB_SYS_TABLES crashes after ALTER TABLE

On 5.1.47-rel11.3-53, I ran the following,

15147> create database test;
15147> use test;
15147> create table t(a int) engine=innodb;
15147> alter table t add key(a);
15147> alter table t add key(a), engine=innodb;

Then in another connection, (I am not sure exactly when the server crashed -- did it crash on the ALTER above, or on the SELECT...?), I ran

15147> select * from INNODB_SYS_TABLES limit 5;

The result is:

100830 22:14:00 - 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=8384512
read_buffer_size=131072
max_used_connections=2
max_threads=151
threads_connected=2
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 337787 K
bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

thd: 0x9acef60
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 = 0xb6e32388 thread_stack 0x30000
./libexec/mysqld(my_print_stacktrace+0x21)[0x84ff711]
./libexec/mysqld(handle_segfault+0x37f)[0x81f259f]
[0x32d400]
./libexec/mysqld(_Z24get_schema_tables_resultP4JOIN23enum_schema_table_state+0x1bb)[0x8318e3b]
./libexec/mysqld(_ZN4JOIN4execEv+0x47e)[0x827b27e]
./libexec/mysqld(_Z12mysql_selectP3THDPPP4ItemP10TABLE_LISTjR4ListIS1_ES2_jP8st_orderSB_S2_SB_yP13select_resultP18st_select_lex_unitP13st_select_lex+0x158)[0x827d958]
./libexec/mysqld(_Z13handle_selectP3THDP6st_lexP13select_resultm+0x146)[0x827e246]
./libexec/mysqld[0x81fed2e]
./libexec/mysqld(_Z21mysql_execute_commandP3THD+0x1082)[0x8203ae2]
./libexec/mysqld(_Z11mysql_parseP3THDPKcjPS2_+0x37f)[0x820cebf]
./libexec/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x459)[0x820d329]
./libexec/mysqld(_Z10do_commandP3THD+0x13f)[0x820e64f]
./libexec/mysqld(handle_one_connection+0x6b6)[0x81fc106]
/lib/libpthread.so.0[0x5e6ab5]
/lib/libc.so.6(clone+0x5e)[0x519d8e]
Trying to get some variables.
Some pointers may be invalid and cause the dump to abort...
thd->query at 0xa7c045a0 is an invalid pointer
thd->thread_id=2
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.

After restarting, any query to INNODB_SYS_TABLES is crashing the server with a stack trace like the following:

100830 22:17:03 - 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=8384512
read_buffer_size=131072
max_used_connections=2
max_threads=151
threads_connected=2
It is possible that mysqld could use up to
key_buffer_size + (read_buffer_size + sort_buffer_size)*max_threads = 337787 K
bytes of memory
Hope that's ok; if not, decrease some variables in the equation.

thd: 0x96f8df0
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 = 0xa7bce388 thread_stack 0x30000
./libexec/mysqld(my_print_stacktrace+0x21)[0x84ff711]
./libexec/mysqld(handle_segfault+0x37f)[0x81f259f]
[0x37a400]
./libexec/mysqld(_Z24get_schema_tables_resultP4JOIN23enum_schema_table_state+0x1bb)[0x8318e3b]
./libexec/mysqld(_ZN4JOIN4execEv+0x47e)[0x827b27e]
./libexec/mysqld(_Z12mysql_selectP3THDPPP4ItemP10TABLE_LISTjR4ListIS1_ES2_jP8st_orderSB_S2_SB_yP13select_resultP18st_select_lex_unitP13st_select_lex+0x158)[0x827d958]
./libexec/mysqld(_Z13handle_selectP3THDP6st_lexP13select_resultm+0x146)[0x827e246]
./libexec/mysqld[0x81fed2e]
./libexec/mysqld(_Z21mysql_execute_commandP3THD+0x1082)[0x8203ae2]
./libexec/mysqld(_Z11mysql_parseP3THDPKcjPS2_+0x37f)[0x820cebf]
./libexec/mysqld(_Z16dispatch_command19enum_server_commandP3THDPcj+0x459)[0x820d329]
./libexec/mysqld(_Z10do_commandP3THD+0x13f)[0x820e64f]
./libexec/mysqld(handle_one_connection+0x6b6)[0x81fc106]
/lib/libpthread.so.0[0x5e6ab5]
/lib/libc.so.6(clone+0x5e)[0x519d8e]
Trying to get some variables.
Some pointers may be invalid and cause the dump to abort...
thd->query at 0x974d978 = select * from INNODB_SYS_TABLES limit 5
thd->thread_id=2
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.