bin/47121: mailx(1) can be fooled to join messages

[sdaoden%gmail.com@localhost]

>Number:         47121
>Category:       bin
>Synopsis:       mailx(1) can be fooled to join messages
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Oct 24 22:05:00 +0000 2012
>Originator:     Steffen
>Release:        HEAD
>Organization:
>Environment:
NetBSD nbsd6 6.0 NetBSD 6.0 (GENERIC) i386
>Description:
When "e"diting a MBOX message mail(1) will place the entire message in the 
editor, i.e., including the separating newline.
If that newline is removed the edited message will be joined with the message 
before it.
(The good news is that this can be reversed just the same way.)
>How-To-Repeat:
mail -f the following MBOX and "e"dit the first message by just stripping off 
the final newline.

From S-Postman Thu May 10 20:40:54 2012
From: <1234567890%abc.com@localhost>
To: <recei%ver.com@localhost>
Subject: Example mail
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Status: RO

I agree it has nothing to do with tz, so wouldn't it have been more conside=
rate not to send it?

From S-Postman Thu May 10 20:40:54 2012
From: <1234567890%abc.com@localhost>
To: <recei2%ver2.com@localhost>
Subject: Example mail2
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Status: O

I agree it has nothing to do with tz, so wouldn't it have been more conside=
rate not to send it?


>Fix:
I've fixed that for S-nail(1) like follows, though it is hacky yet.
This patch doesn't apply to NetBSD mail(1), which is (yet) more sophisticated 
since it differences in between header and body afais.

--- /Users/steffen/tmp/f.new    2012-10-24 23:50:48.000000000 +0200
+++ /Users/steffen/tmp/f.old    2012-10-24 23:50:34.000000000 +0200
@@ -80,14 +80,12 @@ visual(void *v)
 static int 
 edit1(int *msgvec, int type)
 {
-       int c;
-       int i;
+       int c, i, wb, lastnl;
        FILE *fp = NULL;
        struct message *mp;
        off_t size;
        char *line = NULL;
        size_t linesize;
-       int     wb;
 
        /*
         * Deal with each message to be edited . . .
@@ -114,25 +111,35 @@ edit1(int *msgvec, int type)
                did_print_dot = 1;
                touch(mp);
                sigint = safe_signal(SIGINT, SIG_IGN);
-               fp = run_editor(fp, mp->m_size, type,
+               --mp->m_size; /* XXX[edithack] strip final NL */
+               fp = run_editor(fp, -1/*mp->m_size*/, type,
                                (mb.mb_perm & MB_EDIT) == 0 || !wb,
                                NULL, mp, wb ? SEND_MBOX : SEND_TODISP_ALL,
                                sigint);
+               ++mp->m_size; /* XXX[edithack] */
                if (fp != NULL) {
                        fseek(mb.mb_otf, 0L, SEEK_END);
                        size = ftell(mb.mb_otf);
                        mp->m_block = mailx_blockof(size);
                        mp->m_offset = mailx_offsetof(size);
-                       mp->m_size = fsize(fp);
                        mp->m_lines = 0;
                        mp->m_flag |= MODIFY;
                        rewind(fp);
+                       lastnl = 0;
+                       size = 0;
                        while ((c = getc(fp)) != EOF) {
-                               if (c == '\n')
+                               if ((lastnl = c == '\n'))
                                        mp->m_lines++;
                                if (putc(c, mb.mb_otf) == EOF)
                                        break;
+                               ++size;
                        }
+                       /* MBOX finalize XXX[edithack] is this always MBOX? */
+                       if (! lastnl && putc('\n', mb.mb_otf) != EOF)
+                               ++size;
+                       if (putc('\n', mb.mb_otf) != EOF)
+                               ++size;
+                       mp->m_size = (size_t)size;/*XXX[edithack] inc.MBOX?!? */
                        if (ferror(mb.mb_otf))