gEDA-dev: yet another dicer bug

[DJ Delorie]

> Why do you think that's a dicer bug?  The dicer is just the part
> that turns a polygon (collection of regions and holes) into a bunch
> of regions with no holes by "dicing" it (cutting through the holes).

Perhaps my nomenclature is off, then.  It's not doing the PolygonPlows
for those lines and pads.

> This bug is probably a polygon intersecting bug of some kind.  The
> last one posted to the list was triggered by having one diagonal
> line made up of two segments (that could have been one but was not
> for some reason).

I checked for that.

> > If I delete the polygon and redraw it, I get the same symptoms.
> 
> The way to isolate this is to draw a polygon over a smaller part of the
> affected area and see if it clears right.  If so, undo and pick another
> area.  If not, try to reduce the size until you see which element is
> causing a problem.

If I delete the big chip, I can add a poly and it clears properly.
However, if I start with the poly there and then delete the chip, the
polygon gets even more messed up.

I noticed in a different board today that using the insert tool to
insert a corner can mess up the polygon plows too.