Regression in mailcheck mailbox info initialization

[bugrep1209]

Configuration Information [Automatically generated, do not change]:
Machine: i686
OS: linux-gnu
Compiler: i686-pc-linux-gnu-gcc
Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i686' 
-DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i686-pc-linux-gnu' 
-DCONF_VENDOR='pc' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' -DSHELL 
-DHAVE_CONFIG_H   -I.  -I. -I./include -I./lib  
-DDEFAULT_PATH_VALUE='/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin'
 -DSTANDARD_UTILS_PATH='/bin:/usr/bin:/sbin:/usr/sbin' 
-DSYS_BASHRC='/etc/bash/bashrc' -DSYS_BASH_LOGOUT='/etc/bash/bash_logout' 
-DNON_INTERACTIVE_LOGIN_SHELLS -DSSH_SOURCE_BASHRC -O2 -march=prescott -pipe 
-fomit-frame-pointer -fno-ident
uname output: Linux limbic 2.6.27-gentoo-r10 #1 SMP Sat Jul 18 20:29:28 CDT 
2009 i686 Intel(R) Core(TM)2 Quad CPU Q9550 @ 2.83GHz GenuineIntel GNU/Linux
Machine Type: i686-pc-linux-gnu

Bash Version: 4.0
Patch Level: 35
Release Status: release

Description:
        There is a regression in the mail checking behavior where bash
        now unconditionally reports that there is mail in a checked
        mailbox $MAILCHECK seconds after bash is initially started.

Repeat-By:
        Start an interactive shell setting the MAIL environment variable
        to an existing, non-empty mail file in .bashrc.  For example:

                MAIL=/var/mail/foo

        After $MAILCHECK seconds (default: 60) after the shell is started,
        do any short command (a good one would be 'sleep $MAILCHECK'
        and the message:

                You have mail in /var/mail/foo

        Will appear.  While this is technically correct (there is mail
        in /var/mail/foo), I am not sure that the shell really should be
        reporting this fact shortly after startup.  This behavior also
        differs from the shell's previous behavior.

Fix:
        This appears to be a regression in mailcheck.c resulting from
        the following issue (from CHANGES):

        u.  Fixed the initialization of mailboxes to not cause maildirs to be 
read
            (and stat(2) called for every message file) at shell startup.

        While the maildirs are no longer stat(2)'d upon startup, the struct
        containing the mail file information is not valid...so as soon as
        $MAILCHECK seconds lapse, and stat *is* called for all of the mail
        files with valid file date/size information (that differs from
        the valid information that was just read), the shell interprets
        this as a change in the mail file, and the mail status message
        is displayed.

        I believe that the flag MBOX_INITIALIZED was intended to be used
        to detect this situation, and therefore the fix (patch below) uses
        that flag as I understand its definition.  While the flag was
        set, there is nothing checking it.  The patch below simply adds
        this check, and calls the update_mail_file() function (that
        does the stat, initializes the struct, and sets MBOX_INITIALIZED).

--- mailcheck.c.ORIG    2009-01-04 13:32:37.000000000 -0600
+++ mailcheck.c 2009-12-22 16:48:08.000000000 -0600
@@ -429,6 +429,11 @@
        {
          int file_is_bigger;
 
+         if (!(mailfiles[i]->flags & MBOX_INITIALIZED)) {
+           update_mail_file (i);
+           continue;
+         }
+
          use_user_notification = mailfiles[i]->msg != (char *)NULL;
          message = mailfiles[i]->msg ? mailfiles[i]->msg : _("You have mail in 
$_");