Ticket #14195: trac_14195.patch

sage/numerical/backends/cplex_backend.pxd

@@ -206 +206 @@
      int CPX_PARAM_SOLNPOOLINTENSITY = 2107
      int CPX_MAX = -1
      int CPX_MIN = 1
+
+cdef extern from "../../local/include/cpxconst.h":
+
+     # Solution quality
+     #
+     # The problem either has a simplex basis
+     int CPX_BASIC_SOLN
+
+     # The problem has a primal and dual solution but no basis
+     int CPX_NONBASIC_SOLN
+
+     # The problem has a primal solution but no corresponding dual solution
+     int CPX_PRIMAL_SOLN
+
+     # The problem has no solution
+     int CPX_NO_SOLN
+
+
+
+

sage/numerical/backends/cplex_backend.pyx

@@ -810 +810 @@
         cdef double * c_coeff = <double *> sage_malloc(n * sizeof(double))
         cdef int * c_indices = <int *> sage_malloc(n * sizeof(int))
         cdef int * c_col = <int *> sage_malloc(n * sizeof(int))
-        
+
         for 0<= i < n:
             c_coeff[i] = coeffs[i]
             c_indices[i] = indices[i]
@@ -849 +849 @@
             ...
             MIPSolverException: ...
         """
-    
         cdef int status
         cdef int ptype
-        cdef int solnmethod_p, solntype_p, pfeasind_p, dfeasind_p 
+        cdef int solnmethod_p, solntype_p, pfeasind_p, dfeasind_p
 
         ptype = CPXgetprobtype(self.env, self.lp)
 
@@ -868 +867 @@
         status = CPXsolninfo(self.env, self.lp, &solnmethod_p, &solntype_p, &pfeasind_p, &dfeasind_p)
         check(status)
 
-        if not pfeasind_p:
-            raise MIPSolverException("CPLEX: The primal has no feasible solution")
-        if not dfeasind_p:
-            raise MIPSolverException("CPLEX: The problem is unbounded")
-
+        if solntype_p == CPX_NO_SOLN:
+            if not pfeasind_p:
+                raise MIPSolverException("CPLEX: The primal has no feasible solution")
+            elif not dfeasind_p:
+                raise MIPSolverException("CPLEX: The problem is unbounded")
+            else:
+                raise MIPSolverException("CPLEX: No solution has been found, but no idea why")
 
         return 0
 
-
     cpdef get_objective_value(self):
         r"""
         Returns the value of the objective function.