Assertion error when operating on degenerate area

[GoogleCodeExporter]

In the shell, execute
    PYTHONPATH=.libs python -c 'import area; area.Area().Offset(1.0)'

The snippet should execute without error.  However, it encounters an assertion 
error instead:
python: kbool/src/graph.cpp:236: void Graph::AddLink(Node*, Node*, int): 
Assertion `begin && end' failed.
Aborted

Other operations such as Subtract also give similar errors when either
of their inputs are degenerate.

(I am using SVN revision 62 on 64-bit Ubuntu 10.04, but I have no reason to 
believe this is architecture-dependent)

The attached patch makes operations on degenerate Areas non-fatal, and appears 
to give expected results for the cases I've tested.

Original issue reported on code.google.com by [email protected] on 26 Sep 2010 at 6:46

Attachments:

• 0001-Don-t-error-when-an-area-is-degenerate.patch