[boost] Re: [BGL] Bug in transitive_closure algorithm?

From: Jeremy Siek (jsiek_at_[hidden])
Date: 2003-10-29 16:13:26

Hi Guys,

On Wednesday, October 29, 2003, at 05:29 AM, Vladimir Prus wrote:
> Luckily, I can claim that I'm completely innocent of this bug. It 
> turns out
> that libs/graph/test/transitive_closure_test.cpp was seroiusly changed 
> in
> revision 1.3. It now tests all edges in transitive closure are valid, 
> but it
> does not test that transitive closure has all edges.
>

I've added the test for all edges.
>

> Oh.. my! There are two serious bugs which the buggy testcase did not 
> catch.
> First is the one you've found. Second is that if original graph has a
> loopback, then transitive closure will not have it. Could you grab the 
> fixed
> version from
>
>      
> http://zigzag.cs.msu.su:7813/boost/boost/graph/transitive_closure.hpp
>
> and try it. It passes all tests for me. I also attach the diff for 
> reference.
>

I've checked in your fixes.

> Jeremy, something should be done about it? I think we need to restore 
> the 1.2
> version of the testcase. I'm not sure about code. Could you tell how to
> process transitive_closure.w? I get error from nuweb.

It may need my special version of nuweb. I'll look into this later.

Ciao,
Jeremy