[Cbc] Wrong objective value of small IP

[John Forrest]

Alpar,

Fixed in trunk.  If you remind me in a week I can put fix in stable 2.6,
or you can just replace CbcModel:AddIntegers in stable by one in trunk.
I would prefer to be cautious in stable as it is a small change but if I
have got it wrong it could be disastrous.  It all looks OK on my checks.

The code for turning continuous variables into integer ones was broken
and

2*x1 + x2 <= 2

where x2 is integer

had a stupid mistake where it forgot that the coefficient of x2 was 1
and treated constraint as if all entries were 2 - so thought x1 would be
integer valued.

John Forrest

On Fri, 2011-04-15 at 11:36 +0200, Alpár Jüttner wrote:
> Hi,
> 
> COIN-OR::LEMON provides interface to several LP/MIP solvers including
> CLP and CBC. Being perhaps the best open source solvers around, their
> support is of high priority for us. Unfortunately our standard unit test
> fails on CBC both using version 2.6.4 and the latest svn trunk (-r1638).
> 
> We submitted a bug report (https://projects.coin-or.org/Cbc/ticket/83 )
> about it 19 months ago, but it still seems untouched. Is it possible to
> know anything about the status of this problem?
> 
> Regards,
> Alpar
> 
> 
> 
> 
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