[Dovecot] Crash (segfault) while reading folder headers

[Steve Meyers]

Occasionally, while reading the headers of a folder, Dovecot crashes. 
The visible effect in my mail client is that it will tell me a folder
has a new message, but when I click on it, it will take forever to
load, and there will be no new messages.  When another message comes
in to that folder, the folder begins to work again.

I generated a core from the latest crash, and the gdb dump is included
below.  After generating the core file, I removed the .imap.index*
files from that folder, and it started working again.

I am using Fedora Core 1, with dovecot as an RPM (version
dovecot-0.99.10.5-0.FC1).  It's a Pentium 4 CPU.  Let me know if there
is any more information that would help you resolve this.

==============================================================

Core was generated by `imap'.
Program terminated with signal 11, Segmentation fault.
Reading symbols from /lib/libdl.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib/libdl.so.2
Reading symbols from /lib/tls/libc.so.6...(no debugging symbols found)...done.
Loaded symbols for /lib/tls/libc.so.6
Reading symbols from /lib/ld-linux.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib/ld-linux.so.2
#0  0x08088225 in hash_lookup ()
(gdb) bt full
#0  0x08088225 in hash_lookup ()
No symbol table info available.
#1  0x08060784 in maildir_index_sync_readonly ()
No symbol table info available.
#2  0x0805e586 in maildir_open_mail ()
No symbol table info available.
#3  0x0806bf8a in index_mail_next ()
No symbol table info available.
#4  0x0806aa33 in index_storage_fetch_next ()
No symbol table info available.
#5  0x08055f0c in imap_fetch ()
No symbol table info available.
#6  0x0805254a in cmd_fetch ()
No symbol table info available.
#7  0x08054260 in cmd_uid ()
No symbol table info available.
#8  0x08054a49 in _client_reset_command ()
No symbol table info available.
#9  0x08054ad8 in _client_input ()
No symbol table info available.
#10 0x0808b128 in io_loop_handler_run ()
No symbol table info available.
#11 0x00000001 in ?? ()
No symbol table info available.
#12 0x000025c7 in ?? ()
No symbol table info available.
#13 0x080933f2 in imap_ext_commands ()
No symbol table info available.
#14 0x09c03b30 in ?? ()
---Type <return> to continue, or q <return> to quit---
No symbol table info available.
#15 0x09c03a78 in ?? ()
No symbol table info available.
#16 0xbfefc278 in ?? ()
No symbol table info available.
#17 0x0808d918 in o_stream_flush ()
No symbol table info available.
Previous frame inner to this frame (corrupt stack?)