BUG: gambit-enumpoly infinite loop in quiksolv.imp

[tturocy]

Tobenna Igwe reported an infinite loop in enumpoly on the game below. He's traced it to quiksolv.imp:243. It may or may not give some insight into the issue found in 2x2x2.nfg (see issue #184 ). It also may or may not be something which was introduced relatively recently (and therefore might be fixable).

NFG 1 R "" { "1" "2" "3" }

{ { "1" "2" "3" }
{ "1" "2" "3" }
{ "1" "2" "3" }
}
""

{
{ "" 0.0, 0.0, 0.0 }
{ "" 2.0, 1.0, 1.0 }
{ "" 1.2, 0.6, 0.6 }
{ "" 1.0, 2.0, 1.0 }
{ "" 1.0, 1.0, 2.0 }
{ "" 1.1, 1.5, 1.6 }
{ "" 0.6, 1.2, 0.6 }
{ "" 1.5, 1.1, 1.6 }
{ "" 0.6, 0.6, 1.2 }
{ "" 1.0, 1.0, 2.0 }
{ "" 1.0, 2.0, 1.0 }
{ "" 1.1, 1.6, 1.5 }
{ "" 2.0, 1.0, 1.0 }
{ "" 0.0, 0.0, 0.0 }
{ "" 1.0, 0.5, 0.5 }
{ "" 1.6, 1.1, 1.5 }
{ "" 0.5, 1.0, 0.5 }
{ "" 0.5, 0.5, 1.0 }
{ "" 0.6, 0.6, 1.2 }
{ "" 1.5, 1.6, 1.1 }
{ "" 0.6, 1.2, 0.6 }
{ "" 1.6, 1.5, 1.1 }
{ "" 0.5, 0.5, 1.0 }
{ "" 0.5, 1.0, 0.5 }
{ "" 1.2, 0.6, 0.6 }
{ "" 1.0, 0.5, 0.5 }
{ "" 0.0, 0.0, 0.0 }
}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 

[tturocy]

This also occurs on the full support in the game 2x2x2.nfg in the standard game library.

Unfortunately, this bug has been around so long now that it's present in the oldest version in the repository that still compiles with modern compilers. Given how old this code is, it's going to take some doing figuring out what's going on.