[Cbc-tickets] [COIN-OR Branch-and-Cut MIP Solver] #76: cbc 2.2.2 / release: problem with Lift&Project on miplib2003/fiber.mps

[COIN-OR Branch-and-Cut MIP Solver]

#76: cbc 2.2.2 / release: problem with Lift&Project on miplib2003/fiber.mps
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 Reporter:  tfahle      |       Owner:  somebody
     Type:  defect      |      Status:  new     
 Priority:  major       |   Milestone:          
Component:  component1  |     Version:          
 Keywords:              |  
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 When running cbc 2.2.2/Release  with
 -liftandP on -import fiber.mps -branchAndC

 the code at some point tries to assign an uninitialized variable
 (bestDiretion) to some other variable.
 This can be reprtoduced unter WinXP/MS Vis Studio 2008 and Linux/gcc4.1.2

 Problem in CglLandPSimplex.cpp, fastFindCutImprovingPivotRow()
 There, bestDirection is not initialized when declared and it is possible
 that
 it later on passes all assigments. So it remains uninitialized until it
 copies its (useless) value to variable direction.

 I'm not sure about ::rescanReducedCosts() in the same file.
 I haven't seen a problem there, but the construction is similar and may
 also lead to uninitialised values in rare cases?

-- 
Ticket URL: <https://projects.coin-or.org/Cbc/ticket/76>
COIN-OR Branch-and-Cut MIP Solver <http://projects.coin-or.org/Cbc>
An LP-based branch-and-cut MIP solver.