bash hangs infinitely; related to replace_history_data

Binary package hint: bash

I had it happen several times on my server that bash hung, when exiting from e.g. a "less" statement, before displaying the prompt again.

I've attached gdb then and it revealed the following backtrace. This was with bash from Feisty (3.2-0ubuntu7).

# gdb -p 10345
GNU gdb 6.6-debian
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GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
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This GDB was configured as "i486-linux-gnu".
Attaching to process 10345
Reading symbols from /bin/bash...Reading symbols from /usr/lib/debug/bin/bash...done.
Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
done.
termsig_sighandler (sig=11) at ../bash/sig.c:429
429 ../bash/sig.c: No such file or directory.
        in ../bash/sig.c
(gdb) bt
#0 termsig_sighandler (sig=11) at ../bash/sig.c:429
#1 <signal handler called>
#2 0x080ced45 in replace_history_data (which=-1, old=0x0, new=0x0) at ../../../bash/lib/readline/history.c:420
#3 0x080ca3d5 in rl_free_undo_list () at ../../../bash/lib/readline/undo.c:122
#4 0x080c898b in rl_free_line_state () at ../../../bash/lib/readline/signals.c:455
#5 0x080c8fb9 in rl_signal_handler (sig=2) at ../../../bash/lib/readline/signals.c:145
#6 <signal handler called>
#7 _rl_dispatch_subseq (key=13, map=0x14, got_subseq=0) at ../../../bash/lib/readline/readline.c:723
#8 0x080ba105 in _rl_dispatch (key=13, map=0x14) at ../../../bash/lib/readline/readline.c:687
#9 0x080ba41c in readline_internal_char () at ../../../bash/lib/readline/readline.c:519
#10 0x080ba7a5 in readline (
    prompt=0x8296708 "\001\033[1;31m\002root\001\033[1;31m\002@\001\033[0;32m\002h170368 \001\001\033[0;31m\002[es:1] \002\001\0
33[0;33m\002[scr:1] \001\033[1;31m\002{ \001\033[0;32m\002/etc/monit\001\033[1;31m\002 }\r\n#\001\033[0m\002 ") at ../../../bash
/lib/readline/readline.c:545
#11 0x080683d1 in yy_readline_get () at ../bash/parse.y:1213
#12 0x08064098 in shell_getc (remove_quoted_newline=1) at ../bash/parse.y:1942
#13 0x0806538a in read_token (command=<value optimized out>) at ../bash/parse.y:2562
#14 0x0806898d in yyparse () at ../bash/parse.y:2208
#15 0x080ee0a4 in _DYNAMIC ()
#16 0x080ee084 in _DYNAMIC ()
#17 0x080ee06c in _DYNAMIC ()
#18 0x00000000 in ?? ()
(gdb)