Comment 0 for bug 567232

Doing vm-imap-synchronize in a summary buffer produced an assertion failure:

Debugger entered--Lisp error: (error "assertion failed: (eq (car vm-buffer-types) type)")
  signal(error ("assertion failed: (eq (car vm-buffer-types) type)"))
  error("assertion failed: %S" (eq (car vm-buffer-types) type))
  vm-imap-retrieve-uid-and-flags-data()
  vm-imap-synchronize(nil)
  call-interactively(vm-imap-synchronize)
  execute-extended-command(nil)
  call-interactively(execute-extended-command)