[VM] yet another coding system bug: external MIME bodies

[Julian Bradfield]

vm-mime-retrieve-external-body may corrupt files when it retrieves
them from the external file. This seems to be rarely triggered, but it
bit me when I got some PDF files with Mac line-endings, which VM read
and converted to Unix line endings, thereby breaking all the offsets
in the PDF.

Here is the patch, which I think should apply to trunk as well:

*** vm-mime.el  2011/03/01 22:03:50     1.6
--- vm-mime.el  2011/04/15 20:28:29     1.7
***************
*** 2749,2755 ****
             (if (not (file-exists-p name))
                 (vm-mime-error "file %s does not exist" name))
             (condition-case data
!                (insert-file-contents name)
               (error (signal 'vm-mime-error (cdr data))))))
          ((and (string= access-method "url")
                vm-url-retrieval-methods)
--- 2749,2755 ----
             (if (not (file-exists-p name))
                 (vm-mime-error "file %s does not exist" name))
             (condition-case data
!                (insert-file-contents-literally name)
               (error (signal 'vm-mime-error (cdr data))))))
          ((and (string= access-method "url")
                vm-url-retrieval-methods)
***************
*** 2811,2817 ****
                      (setq name (concat "/" user "@" site ":"
                                         name))))
               (condition-case data
!                  (insert-file-contents name)
                 (error (signal 'vm-mime-error
                                (format "%s" (cdr data)))))))))))
  
--- 2811,2817 ----
                      (setq name (concat "/" user "@" site ":"
                                         name))))
               (condition-case data
!                    (insert-file-contents-literally name)
                 (error (signal 'vm-mime-error
                                (format "%s" (cdr data)))))))))))