[dovecot/core] 489af4: virtual: Wrap mail.get_binary_stream() to fix it

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dovecot/core
  Commit: 489af46c6c1ee32fe6a6ff96a8281f2ef5870c8d
      https://github.com/dovecot/core/commit/489af46c6c1ee32fe6a6ff96a8281f2ef5870c8d
  Author: Timo Sirainen <timo.sirainen at dovecot.fi>
  Date:   2017-11-17 (Fri, 17 Nov 2017)

  Changed paths:
    M src/plugins/virtual/virtual-mail.c

  Log Message:
  -----------
  virtual: Wrap mail.get_binary_stream() to fix it

Fixes using FETCH BINARY[..] with virtual mailboxes crashing with:

Panic: file index-mail-binary.c: line 585 (index_mail_get_binary_stream): assertion failed: (mail->data.stream != NULL)