fix some remaining issues with 1d meshes

meshmode/discretization/connection/opposite_face.py

@@ -43,7 +43,7 @@ def _make_cross_face_batches(queue,
         return cl.array.to_device(queue, ary, array_queue=None)
 
     from meshmode.discretization.connection.direct import InterpolationBatch
-    if tgt_bdry_discr.ambient_dim == 1:
+    if tgt_bdry_discr.dim == 0:
         yield InterpolationBatch(
             from_group_index=i_src_grp,
             from_element_indices=to_dev(src_bdry_element_indices),

meshmode/discretization/poly_element.py

@@ -177,7 +177,9 @@ class QuadratureSimplexElementGroup(SimplexElementGroupBase):
     @memoize_method
     def _quadrature_rule(self):
         dims = self.mesh_el_group.dim
-        if dims == 1:
+        if dims == 0:
+            return mp.Quadrature(np.empty((0, 1)), np.empty((0, 1)))
+        elif dims == 1:
             return mp.LegendreGaussQuadrature(self.order)
         else:
             return mp.XiaoGimbutasSimplexQuadrature(self.order, dims)