periodic in 4.0.2

[Allan Poindexter <apoindex@xxxxxxxxxxxx>]

I have periodic set to something like this:

periodic () { source ~/.zsh.aliases }

In 4.0.2 this segfaults zsh when CR is typed following the first automatic
execution of periodic.  It works if periodic is invoked from the command line.
It works if periodic doesn't source a file.  The problem only appears when
sourcing files within periodic when periodic is being executed after the
PERIOD interval before the prompt.  (Well, at least that is the only thing I
have found to trigger it so far.)