[Dovecot] Segfault in ACL Plugin + user shared folders

[Markus Werner]

Another one:

#0  0xb7fbf424 in __kernel_vsyscall ()
No symbol table info available.
#1  0xb7e7a640 in raise () from /lib/i686/cmov/libc.so.6
No symbol table info available.
#2  0xb7e7c018 in abort () from /lib/i686/cmov/libc.so.6
No symbol table info available.
#3  0x080ee9a5 in default_fatal_finish (type=<value optimized out>, status=0) at failures.c:161
        backtrace = 0x8282480 "imap [0x80ee991] -> imap [0x80eea12] -> imap [0x80ee399] -> imap [0x80b50eb] -> imap(shared_storage_get_namespace+0x2bf) [0x8075fff] -> imap [0x80757d7] -> imap [0x8063034] -> imap(cmd_list_full+0x514"...
#4  0x080eea12 in i_internal_fatal_handler (type=LOG_TYPE_PANIC, status=0, fmt=0x810632c "file %s: line %d (%s): assertion failed: (%s)",
    args=0xbfbda674 "\017\v\021\b\036") at failures.c:441
No locals.
#5  0x080ee399 in i_panic (format=0x810632c "file %s: line %d (%s): assertion failed: (%s)") at failures.c:208
No locals.
#6  0x080b50eb in mail_user_init (username=0x829854e "") at mail-user.c:30
        user = <value optimized out>
        pool = <value optimized out>
        __PRETTY_FUNCTION__ = "mail_user_init"
#7  0x08075fff in shared_storage_get_namespace (_storage=0x82929d0, _name=0xbfbda724, ns_r=0xbfbda728) at shared-storage.c:224
        user = (struct mail_user *) 0x828e270
        ns = (struct mail_namespace *) 0x0
        owner = <value optimized out>
        domain = 0x0
        username = 0x829854e ""
        userdomain = 0x829854e ""
        name = 0x810fc97 "INBOX"
        p = <value optimized out>
        dest = <value optimized out>
        error = <value optimized out>
        prefix = (string_t *) 0x82823b0
        location = <value optimized out>
        ret = <value optimized out>
        static_tab = {{key = 117 'u', value = 0x0, long_key = 0x8110b32 "user"}, {key = 110 'n', value = 0x0, long_key = 0x8109830 "username"}, {
    key = 100 'd', value = 0x0, long_key = 0x8109839 "domain"}, {key = 104 'h', value = 0x0, long_key = 0x8109807 "home"}, {key = 0 '\0', value = 0x0,
    long_key = 0x0}}
        __PRETTY_FUNCTION__ = "shared_storage_get_namespace"
#8  0x080757d7 in shared_list_join_refpattern (list=0x8292dd8, ref=0x8298548 "#User/", pattern=0x8298550 "*") at shared-list.c:148
        ns = <value optimized out>
        ns_ref = 0x829854e ""
        prefix = 0x8292998 "#User/"
#9  0x08063034 in cmd_list_continue (cmd=0x8293448) at cmd-list.c:672
        _data_stack_cur_id = 4
        ctx = (struct cmd_list_context *) 0x82934e0
#10 0x08063a04 in cmd_list_full (cmd=0x8293448, lsub=false) at cmd-list.c:903
        client = (struct client *) 0x82931b8
        args = (const struct imap_arg *) 0x82984e8
        arg = <value optimized out>
        ctx = (struct cmd_list_context *) 0x82934e0
        patterns = {arr = {buffer = 0x8293508, element_size = 4}, v = 0x8293508, v_modifiable = 0x8293508}
        pattern = 0x8298550 "*"
#11 0x08063d09 in cmd_list (cmd=0x8293448) at cmd-list.c:918
No locals.
#12 0x0806700c in client_command_input (cmd=0x8293448) at client.c:603
        client = (struct client *) 0x82931b8
        command = <value optimized out>
        __PRETTY_FUNCTION__ = "client_command_input"
#13 0x080670a9 in client_command_input (cmd=0x8293448) at client.c:652
        client = (struct client *) 0x82931b8
        command = <value optimized out>
        __PRETTY_FUNCTION__ = "client_command_input"
#14 0x080676ed in client_handle_input (client=0x82931b8) at client.c:693
        _data_stack_cur_id = 3
        ret = <value optimized out>
        remove_io = <value optimized out>
        handled_commands = false
#15 0x08067ba3 in client_input (client=0x82931b8) at client.c:748
        cmd = <value optimized out>
        output = (struct ostream *) 0x829336c
        bytes = <value optimized out>
        __PRETTY_FUNCTION__ = "client_input"
#16 0x080f73a0 in io_loop_handler_run (ioloop=0x828aae0) at ioloop-epoll.c:208
        ctx = (struct ioloop_handler_context *) 0x828abe8
        event = (const struct epoll_event *) 0x828ac28
        list = (struct io_list *) 0x82933f0
        io = (struct io_file *) 0x82933c8
        tv = {tv_sec = 1799, tv_usec = 999778}
        t_id = 2
        msecs = <value optimized out>
        ret = 1
        i = 0
        j = 0
        call = <value optimized out>
#17 0x080f6830 in io_loop_run (ioloop=0x828aae0) at ioloop.c:338
No locals.
#18 0x080704c5 in main (argc=Cannot access memory at address 0x4c2f
) at main.c:320