add tests for disjunction constraint, fix constraint free placement

Author: ctdunc

src/pyscipopt/scip.pxd

@@ -1507,6 +1507,7 @@ cdef extern from "scip/cons_disjunction.h":
                                             SCIP_Bool local,
                                             SCIP_Bool modifiable,
                                             SCIP_Bool dynamic)
+
     SCIP_RETCODE SCIPaddConsElemDisjunction(SCIP *scip,
                                             SCIP_CONS *cons,
                                             SCIP_CONS *addcons)

src/pyscipopt/scip.pxi

@@ -2372,19 +2372,27 @@ cdef class Model:
         """
         assert isinstance(cons, ExprCons), "given constraint is not ExprCons but %s" % cons.__class__.__name__
 
+        cdef SCIP_CONS* scip_cons
+
         kwargs = dict(name=name, initial=initial, separate=separate,
                       enforce=enforce, check=check,
                       propagate=propagate, local=local,
                       modifiable=modifiable, dynamic=dynamic,
                       removable=removable,
                       stickingatnode=stickingatnode)
-        # replace empty name with generic one
-        pycons = self.createExprCons(cons, **kwargs)
-        PY_SCIP_CALL(SCIPaddCons(self._scip, (<Constraint>pycons).scip_cons))
-        PY_SCIP_CALL(SCIPreleaseCons(self._scip, &((<Constraint>pycons).scip_cons)))
+        #  we have to pass this back to a SCIP_CONS*
+        # object to create a new python constraint & handle constraint release
+        # correctly. Otherwise, segfaults when trying to query information
+        # about the created constraint later.
+        pycons_initial = self.createExprCons(cons, **kwargs)
+        scip_cons = (<Constraint>pycons_initial).scip_cons
+
+        PY_SCIP_CALL(SCIPaddCons(self._scip, scip_cons))
+        pycons = Constraint.create(scip_cons)
+        PY_SCIP_CALL(SCIPreleaseCons(self._scip, &scip_cons))
+
         return pycons
 
-    
     def addConss(self, conss, name='', initial=True, separate=True,
                  enforce=True, check=True, propagate=True, local=False,
                  modifiable=False, dynamic=False, removable=False,
@@ -2638,7 +2646,6 @@ cdef class Model:
 
         PY_SCIP_CALL(SCIPaddCons(self._scip, scip_cons))
         return Constraint.create(scip_cons)
-
     def addConsSOS2(self, vars, weights=None, name="SOS2cons",
                 initial=True, separate=True, enforce=True, check=True,
                 propagate=True, local=False, dynamic=False,
@@ -3458,6 +3465,7 @@ cdef class Model:
             self.optimize()
         else:
             PY_SCIP_CALL(SCIPsolveConcurrent(self._scip))
+            print("solveconcurrent")
             self._bestSol = Solution.create(self._scip, SCIPgetBestSol(self._scip))
 
     def presolve(self):

tests/test_cons.py

@@ -11,6 +11,7 @@ def test_getConsNVars():
         x[i] = m.addVar("%i" % i)
 
     c = m.addCons(quicksum(x[i] for i in x) <= 10)
+    print(c.__hash__())
     assert m.getConsNVars(c) == n_vars
 
     m.optimize()
@@ -117,7 +118,9 @@ def test_cons_indicator():
     assert c.getConshdlrName() == "indicator"
 
 
-@pytest.mark.xfail(reason="addConsIndicator doesn't behave as expected when binary variable is False. See Issue #717.")
+@pytest.mark.xfail(
+    reason="addConsIndicator doesn't behave as expected when binary variable is False. See Issue #717."
+)
 def test_cons_indicator_fail():
     m = Model()
     binvar = m.addVar(vtype="B")
@@ -131,23 +134,6 @@ def test_cons_indicator_fail():
     m.setSolVal(sol, binvar, 0)
     assert m.checkSol(sol)  # solution should be feasible
 
-def test_addConsDisjunction():
-    m = Model()
-
-    x1 = m.addVar(vtype="C", lb=-1, ub=1)
-    x2 = m.addVar(vtype="C", lb=-3, ub=3)
-    o = m.addVar(vtype="C")
-
-    c = m.addConsDisjunction([x1 <= 0, x2 <= 0])
-    m.addCons(o <= x1 + x2)
-
-    m.setObjective(o, "maximize")
-    m.optimize()
-
-    assert m.isEQ(m.getVal(x1), 0.0)
-    assert m.isEQ(m.getVal(x2), 3.0)
-    assert m.isEQ(m.getVal(o), 3.0)
-    #assert c.getConshdlrName() == "disjunction"
 
 def test_addConsCardinality():
     m = Model()
@@ -170,6 +156,42 @@ def test_printCons():
     m.printCons(c)
 
 
+def test_addConsElemDisjunction():
+    m = Model()
+    x = m.addVar(vtype="c", lb=-10, ub=2)
+    y = m.addVar(vtype="c", lb=-10, ub=5)
+    o = m.addVar(vtype="c")
+
+    m.addCons(o <= (x + y))
+    disj_cons = m.addConsDisjunction([])
+    c1 = m.createExprCons(x <= 1)
+    c2 = m.createExprCons(x <= 0)
+    c3 = m.createExprCons(y <= 0)
+    m.addConsElemDisjunction(disj_cons, c1)
+    disj_cons = m.addConsElemDisjunction(disj_cons, c2)
+    disj_cons = m.addConsElemDisjunction(disj_cons, c3)
+    m.setObjective(o, "maximize")
+    m.optimize()
+    assert m.isEQ(m.getVal(x), 1)
+    assert m.isEQ(m.getVal(y), 5)
+    assert m.isEQ(m.getVal(o), 6)
+
+
+def test_addConsDisjunction_expr_init():
+    m = Model()
+    x = m.addVar(vtype="c", lb=-10, ub=2)
+    y = m.addVar(vtype="c", lb=-10, ub=5)
+    o = m.addVar(vtype="c")
+
+    m.addCons(o <= (x + y))
+    m.addConsDisjunction([x <= 1, x <= 0, y <= 0])
+    m.setObjective(o, "maximize")
+    m.optimize()
+    assert m.isEQ(m.getVal(x), 1)
+    assert m.isEQ(m.getVal(y), 5)
+    assert m.isEQ(m.getVal(o), 6)
+
+
 @pytest.mark.skip(reason="TODO: test getValsLinear()")
 def test_getValsLinear():
     assert True
@@ -178,3 +200,7 @@ def test_getValsLinear():
 @pytest.mark.skip(reason="TODO: test getRowLinear()")
 def test_getRowLinear():
     assert True
+
+
+if __name__ == "__main__":
+    test_getConsNVars()