Fixes potentially outdated value of getVal

src/pyscipopt/scip.pxi

@@ -301,7 +301,7 @@
         raise Exception('SCIP: unspecified error!')
     elif rc == SCIP_NOMEMORY:
         raise MemoryError('SCIP: insufficient memory error!')
     elif rc == SCIP_READERROR:
         raise IOError('SCIP: read error!')
     elif rc == SCIP_WRITEERROR:
         raise IOError('SCIP: write error!')
@@ -1000,8 +1000,8 @@
     """Base class holding a pointer to corresponding SCIP_SOL."""
 
     # We are raising an error here to avoid creating a solution without an associated model. See Issue #625
-    def __init__(self, raise_error = False):
-        if not raise_error:
+    def __init__(self, raise_error = True):
+        if raise_error:
             raise ValueError("To create a solution you should use the createSol method of the Model class.")
 
     @staticmethod
@@ -1025,7 +1025,7 @@
         """
         if scip == NULL:
             raise Warning("cannot create Solution with SCIP* == NULL")
-        sol = Solution(True)
+        sol = Solution(raise_error=False)
         sol.sol = scip_sol
         sol.scip = scip
         return sol
@@ -9628,6 +9628,9 @@
         if not stage_check or self._bestSol.sol == NULL and SCIPgetStage(self._scip) != SCIP_STAGE_SOLVING:
             raise Warning("Method cannot be called in stage ", self.getStage())
 
+        # update best sol
+        self.getBestSol()
+
         if isinstance(expr, MatrixExpr):
             result = np.empty(expr.shape, dtype=float)
             for idx in np.ndindex(result.shape):