bug#8657: 24.0.50; Emacs code that seems to use `*-single-char-property-change' incorrectly

[Chong Yidong]

Katsumi Yamaoka <yamaoka@jpl.org> writes:

> But in XEmacs next-single-char-property-change will return nil
> if no property change is found.

Ah OK, thanks for checking.

> So I've modified the gnus-sum.el code into:
>
>   (if (featurep 'xemacs)
>       (or (next-single-char-property-change end 'invisible)
>           (point-max))
>     (next-single-char-property-change end 'invisible))

I suggest just restoring the old code, and adding a comment about why
the `or' is there.