From 030d976c23288e782feb72e9a4a773530fc342a4 Mon Sep 17 00:00:00 2001
From: Sebastian Heger <heger@m2p.net>
Date: Wed, 26 Jan 2022 22:14:42 +0100
Subject: [PATCH] Fix gap setting after optimize

Fixed rare case when gurobi returns unbounded model with a worthless solution
---
 mip/model.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/mip/model.py b/mip/model.py
index a9b6a915..7c38b2b7 100644
--- a/mip/model.py
+++ b/mip/model.py
@@ -616,8 +616,11 @@ def optimize(
         )
 
         self._status = self.solver.optimize(relax)
-        # has a solution and is a MIP
-        if self.num_solutions and self.num_int > 0:
+        # has a solution
+        if self._status in (
+            mip.OptimizationStatus.OPTIMAL,
+            mip.OptimizationStatus.FEASIBLE,
+        ) and self.num_int > 0:
             best = self.objective_value
             lb = self.objective_bound
             if abs(best) <= 1e-10: