bug#19200: Point adjustemnt moves *into* invisible text

[Stefan Monnier]

>> So someone needs to step through the code and figure out why this
>> doesn't happen.
> I guess you expected me to be that Someone...

Actually, no, I expected Michael would be motivated to do it, since he's
the one presumably affected.

> get_char_property_and_overlay returns nil for position 3 - 1 = 2, and
> the while loop is exited with beg = 3 and end = 5.

Good so far.

> Since point is 5,
> we land here:

OK, so indeed, the problem is in

          /* Move away from the inside area.  */
          if (beg < PT && end > PT)

In our case, end==PT, but we do want to enter this `if's body to move PT
to `beg'.


        Stefan