[bugfix] fix broken assertion.

This patch fixes the errornous commits e8d16384 1a2f4d0f

The introduced range checks were plain wring, as they neglected the nested structure of the BlockVector. We now use b.dim() to get the flat size.

This fixes flyspray/FS#1724 (closed).

dune/istl/superlu.hh

@@ -561,11 +561,11 @@ namespace Dune
void SuperLU<BCRSMatrix<FieldMatrix<T,n,m>,A> >
::apply(domain_type& x, range_type& b, InverseOperatorResult& res)
{
-    if (mat.N() != b.size())
+    if (mat.N() != b.dim())
DUNE_THROW(ISTLError, "Size of right-hand-side vector b does not match the number of matrix rows!");
-    if (mat.M() != x.size())
+    if (mat.M() != x.dim())
DUNE_THROW(ISTLError, "Size of solution vector x does not match the number of matrix columns!");
-    if(mat.M()+mat.N()==0)
+    if (mat.M()+mat.N()==0)
DUNE_THROW(ISTLError, "Matrix of SuperLU is null!");
SuperMatrix* mB = &B;
@@ -577,7 +577,7 @@ namespace Dune
SuperLUDenseMatChooser<T>::create(&X, (int)mat.N(), 1,  reinterpret_cast<T*>(&x[0]), (int)mat.N(), SLU_DN, GetSuperLUType<T>::type, SLU_GE);
first=false;
}else{
-        ((DNformat*) B.Store)->nzval=&b[0];
+        ((DNformat*)B.Store)->nzval=&b[0];
((DNformat*)X.Store)->nzval=&x[0];
}
} else {