bash/readline coredumps

Hi.
Lately I am getting core dumps from bash (bash-2.05b.007_2 from ports).
To reproduce: type a command that spans multiple lines, like

echo '
'

Then bring up the last line with cursor-up or ^P and press enter.

Some gdb output:

(gdb) bt
#0  rl_do_undo () at /usr/src/gnu/lib/libreadline/readline/../../../../contrib/libreadline/undo.c:124
#1  0x280ee279 in rl_revert_line (count=1, key=0)
    at /usr/src/gnu/lib/libreadline/readline/../../../../contrib/libreadline/undo.c:239
#2  0x28102e4d in readline_internal_teardown (eof=0)
    at /usr/src/gnu/lib/libreadline/readline/../../../../contrib/libreadline/readline.c:372
#3  0x281039fc in readline (prompt=0x80c4180 "mboland_at_leefnet:~$ ")
    at /usr/src/gnu/lib/libreadline/readline/../../../../contrib/libreadline/readline.c:504
#4  0x08058623 in yy_input_name ()
#5  0x080c4180 in ?? ()
#6  0x0807c5e8 in termination_unwind_protect ()
#7  0x08059fa1 in yyerror ()
#8  0x0805ae83 in yyerror ()
#9  0x0805d529 in yyparse ()
#10 0x08058133 in parse_command ()
#11 0x080581dd in read_command ()
#12 0x0805831c in reader_loop ()
#13 0x08057441 in main ()
(gdb) print rl_undo_list
$2 = (UNDO_LIST *) 0x30313100

This is -CURRENT from last Friday, but the problem has been around longer.

Anyone any ideas?

Cheers
Michiel