From f7453bcd7ea34fff096ce1441ecd0b18ac2e8746 Mon Sep 17 00:00:00 2001
From: Miles Lubin <miles.lubin@gmail.com>
Date: Sun, 19 Feb 2017 21:31:43 -0500
Subject: [PATCH] hack to correct getobjbound

---
 src/GLPKInterfaceMIP.jl | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/GLPKInterfaceMIP.jl b/src/GLPKInterfaceMIP.jl
index f2f80bc..627f2ba 100644
--- a/src/GLPKInterfaceMIP.jl
+++ b/src/GLPKInterfaceMIP.jl
@@ -509,7 +509,17 @@ end
 
 getobjval(lpm::GLPKMathProgModelMIP) = GLPK.mip_obj_val(lpm.inner)
 
-getobjbound(lpm::GLPKMathProgModelMIP) = lpm.objbound
+function getobjbound(lpm::GLPKMathProgModelMIP)
+    # This is a hack. We observed some cases where mip_status == OPT
+    # and objval and objbound didn't match.
+    # We can fix this case, but objbound may still be incorrect in
+    # cases where the solver terminates early.
+    if GLPK.mip_status(lpm.inner) == GLPK.OPT
+        return GLPK.mip_obj_val(lpm.inner)
+    else
+        return lpm.objbound
+    end
+end
 
 function getsolution(lpm::GLPKMathProgModelMIP)
     lp = lpm.inner