Re: text_property_stickiness

[Richard Stallman <rms@gnu.org>]

    *** emacs/src/textprop.c.~1.147.~	2006-05-17 13:33:46.000000000 -0400
    --- emacs/src/textprop.c	2006-06-24 16:24:46.000000000 -0400
    ***************
    *** 1787,1792 ****
    --- 1787,1794 ----
	    /* PROP is rear-non-sticky.  */
	    is_rear_sticky = 0;
	  }
    +   else
    +     return 0;

This would make text_property_stickiness return 0 when POS is before
BEGV.  Does that give correct results in calls from find_field?  I
doubt it.

Meanwhile, if POS is after ZV, Fget_text_property will get an error
in the following code, right?

	/* Consider following character.  */
	front_sticky = Fget_text_property (pos, Qfront_sticky, buffer);

This problem really is tricky, for the reasons I explained.
It could be that we need to make sure find_field is never called
for positions outside BEGV..ZV.  That may require changes in callers
at higher level, and changes in the specs of the field functions.