[Clp-tickets] [COIN-OR Linear Programming Solver] #82: Unbounded ray not found when there are no constraint

[COIN-OR Linear Programming Solver]

#82: Unbounded ray not found when there are no constraint
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 Reporter:  blegat      |      Owner:  somebody
     Type:  defect      |     Status:  new
 Priority:  major       |  Milestone:
Component:  component1  |    Version:
 Keywords:              |
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 Dear Clp maintainers,

 For the trivial problem (see attachment for an mps):

 Minimize x0 + x1 Subject To

 Bounds

 x1 >= 0
 x1 free

 End

 Clp correctly detects it to be unbounded but returns NULL when asked for
 the Unbounded ray (see [https://github.com/JuliaOpt/Clp.jl/pull/20 here]).

 While it may look silly to ask Clp to solve such a trivial problem, this
 actually happens as part of a larger algorithms (see
 [https://github.com/blegat/StochasticDualDynamicProgramming.jl here]) so
 it wasn't generated by hand and the fact that Clp fails on such simple
 problems makes it unusable for the whole algorithm :(

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Ticket URL: <https://projects.coin-or.org/Clp/ticket/82>
COIN-OR Linear Programming Solver <http://projects.coin-or.org/Clp>
A linear programming solver.