Re: NEWS and invisible text

[Richard Stallman <rms@gnu.org>]

    >    ** Only one of the beginning or end of an invisible, intangible region is
    >    considered an acceptable value for point; which one is determined by
    >    examining how the invisible/intangible properties are inherited when new
    >    text is inserted adjacent to them. 


    Is that determined by examining the front-sticky and rear-sticky properties?

Yes.

    >    If text inserted at the beginning would
    >    inherit the invisible/intangible properties, then that position is
    >    considered unacceptable, and point is forced to the position following the
    >    invisible/intangible text.  If text inserted at the end would inherit the
    >    properties, then the opposite happens.

    What happens when both conditions are true?

I think you can't put point at either end, in that case.
But I didn't test it, I just read the code.  Want to test it?
Here's a rewrite that says what I think the code does.


** Only one of the beginning or end of an invisible, intangible region is
considered an acceptable value for point; which one is determined by
examining how the invisible/intangible properties are inherited when new
text is inserted adjacent to them.  (The `front-sticky' and `rear-sticky'
properties control this.)

If text inserted at the beginning would inherit the
invisible/intangible properties, then that position is considered
unacceptable, and point is forced to continue (if moving forwards, to
the position following the invisible/intangible text; if moving
backwards, to one position before).  If text inserted at the end would
inherit the properties, then that position is considered unacceptable,
and point is forced to keep moving (if moving backwards, to the
position preceding the invisible/intangible text; if moving forwards,
to one position later).