Re: 23.0.50; savehist save invalid syntax

[Richard Stallman]

    I looked a bit closer at the rest as well, and I think that
    `savehist-prin1-readable' needs to actually read what it prints (like it did
    before Davis's patch). It should raise an error (hence remove the written
    entry and return nil) if either the write or the read fails.

Why is this necessary, if `prin1' signals an error when printing anything
unreadable?