Fix: Replaced accidental `continue` by `break` in boundaries/createindexlist.py

There was a continue instead of a break statement in the python code for index list creation, causing the single_link flag to be ignored. The test cases for this are updated in lbmpy!41 (merged).

pystencils_tests/test_boundary_indexlist_creation.py

+import numpy as np
+from itertools import product
+import pystencils.boundaries.createindexlist as cil
+
+import pytest
+
+@pytest.mark.parametrize('single_link', [False, True])
+@pytest.mark.skipif(not cil.cython_funcs_available, reason='Cython functions are not available')
+def test_equivalence_cython_python_version(single_link):
+    #   D2Q9
+    stencil_2d = tuple((x,y) for x,y in product([-1, 0, 1], [-1, 0, 1]))
+    #   D3Q19
+    stencil_3d = tuple((x,y,z) for x,y,z in product([-1, 0, 1], [-1, 0, 1], [-1, 0, 1]) if abs(x) + abs(y) + abs(z) < 3)
+
+    for dtype in [int, np.int16, np.uint32]:
+        fluid_mask = dtype(1)
+        mask = dtype(2)
+        flag_field_2d = np.ones([15, 16], dtype=dtype) * fluid_mask
+        flag_field_3d = np.ones([15, 16, 17], dtype=dtype) * fluid_mask
+
+        flag_field_2d[0, :] = mask
+        flag_field_2d[-1, :] = mask
+        flag_field_2d[7, 7] = mask
+
+        flag_field_3d[0, :, :] = mask
+        flag_field_3d[-1, :, :] = mask
+        flag_field_3d[7, 7, 7] = mask
+
+        result_python_2d = cil._create_boundary_neighbor_index_list_python(flag_field_2d, 1, mask, fluid_mask,
+                                                                           stencil_2d, single_link)
+
+        result_python_3d = cil._create_boundary_neighbor_index_list_python(flag_field_3d, 1, mask, fluid_mask,
+                                                                           stencil_3d, single_link)
+
+        result_cython_2d = cil.create_boundary_index_list(flag_field_2d, stencil_2d, mask,
+                                                          fluid_mask, 1, True, single_link)
+        result_cython_3d = cil.create_boundary_index_list(flag_field_3d, stencil_3d, mask,
+                                                          fluid_mask, 1, True, single_link)
+
+        np.testing.assert_equal(result_python_2d, result_cython_2d)
+        np.testing.assert_equal(result_python_3d, result_cython_3d)
+
+@pytest.mark.parametrize('single_link', [False, True])
+@pytest.mark.skipif(not cil.cython_funcs_available, reason='Cython functions are not available')
+def test_equivalence_cell_idx_list_cython_python_version(single_link):
+    #   D2Q9
+    stencil_2d = tuple((x,y) for x,y in product([-1, 0, 1], [-1, 0, 1]))
+    #   D3Q19
+    stencil_3d = tuple((x,y,z) for x,y,z in product([-1, 0, 1], [-1, 0, 1], [-1, 0, 1]) if abs(x) + abs(y) + abs(z) < 3)
+
+    for dtype in [int, np.int16, np.uint32]:
+        fluid_mask = dtype(1)
+        mask = dtype(2)
+        flag_field_2d = np.ones([15, 16], dtype=dtype) * fluid_mask
+        flag_field_3d = np.ones([15, 16, 17], dtype=dtype) * fluid_mask
+
+        flag_field_2d[0, :] = mask
+        flag_field_2d[-1, :] = mask
+        flag_field_2d[7, 7] = mask
+
+        flag_field_3d[0, :, :] = mask
+        flag_field_3d[-1, :, :] = mask
+        flag_field_3d[7, 7, 7] = mask
+
+        result_python_2d = cil._create_boundary_cell_index_list_python(flag_field_2d, mask, fluid_mask,
+                                                                       stencil_2d, single_link)
+
+        result_python_3d = cil._create_boundary_cell_index_list_python(flag_field_3d, mask, fluid_mask,
+                                                                       stencil_3d, single_link)
+
+        result_cython_2d = cil.create_boundary_index_list(flag_field_2d, stencil_2d, mask, fluid_mask, None,
+                                                          False, single_link)
+        result_cython_3d = cil.create_boundary_index_list(flag_field_3d, stencil_3d, mask, fluid_mask, None,
+                                                          False, single_link)
+
+        np.testing.assert_equal(result_python_2d, result_cython_2d)
+        np.testing.assert_equal(result_python_3d, result_cython_3d)