bug#7746: SERIOUS BUG: mail-strip-quoted-names bug causing unrmail to lose mail

[Mark Lillibridge]

mail-strip-quoted-names in mail/mail-utils.el (at least version 23.1
onwards) contains the following code:

mail-utils.el:187:
           (with-current-buffer (get-buffer-create " *temp*")
             (erase-buffer)
             ...
             (erase-buffer))

This code erases the buffer " *temp*" even if it is being used by
another piece of code!  This is particularly bad because this is the
first buffer used by with-temp-buffer.

A simple fix is to switch to using with-temp-buffer, which always
creates and destroys a new buffer (patch at end):

           (with-temp-buffer
              ...
              )


    This bug breaks unrmail badly, causing it to discard all messages
after one containing a from line that causes that block of code to be
executed (roughly, from lines that contain nested comments).  This is
because unrmail loads the file to be converted into a buffer created
with with-temp-buffer, which is in turn erased prematurely by
mail-strip-quoted-names.  [There is a longer discussion about this on
the developers mailing list.]

    As this bug causes the permanent loss of e-mail, it should probably
be fixed posthaste, including in version 23.

- Mark

ts-rhel5 [158]% diff mail-utils.el new-mail-utils.el
187,188c187
<          (with-current-buffer (get-buffer-create " *temp*")
<            (erase-buffer)
---
>          (with-temp-buffer
201,202c200
<            (setq address (buffer-string))
<            (erase-buffer))
---
>            (setq address (buffer-string)))