From 021bb280c9b4cad713ecdd516c9ef8b9ee97bd2c Mon Sep 17 00:00:00 2001
From: Patrick Shriwise <pshriwise@gmail.com>
Date: Fri, 4 Nov 2022 22:45:37 -0500
Subject: [PATCH] Adding initial test for exporting model.xmls. Correcting
 material maps

---
 openmc/model/model.py          |  3 ++-
 tests/unit_tests/test_model.py | 21 +++++++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/openmc/model/model.py b/openmc/model/model.py
index bc8f0b531..6950642e0 100644
--- a/openmc/model/model.py
+++ b/openmc/model/model.py
@@ -230,8 +230,9 @@ class Model:
 
         model.settings = openmc.Settings.from_xml_element(root.find('settings'))
         model.materials = openmc.Materials.from_xml_element(root.find('materials'))
+        materials = {str(m.id): m for m in model.materials}
         model.geometry = \
-        openmc.Geometry.from_xml_element(root.find('geometry'), model.materials)
+        openmc.Geometry.from_xml_element(root.find('geometry'), materials)
 
         if root.find('tallies'):
             model.tallies = openmc.Tallies.from_xml_element(root.find('tallies'))
diff --git a/tests/unit_tests/test_model.py b/tests/unit_tests/test_model.py
index 9b05ed2a5..ce81b00ee 100644
--- a/tests/unit_tests/test_model.py
+++ b/tests/unit_tests/test_model.py
@@ -7,6 +7,8 @@ import pytest
 import openmc
 import openmc.lib
 
+from .. import cdtemp
+
 
 @pytest.fixture(scope='function')
 def pin_model_attributes():
@@ -529,3 +531,22 @@ def test_calc_volumes(run_in_tmpdir, pin_model_attributes, mpi_intracomm):
     assert openmc.lib.materials[3].volume == mats[2].volume
 
     test_model.finalize_lib()
+
+def test_model_xml():
+
+    with cdtemp():
+        # load a model from examples
+        pwr_model = openmc.examples.pwr_core()
+
+        # export to separate XMLs manually
+        pwr_model.settings.export_to_xml('settings_ref.xml')
+        pwr_model.materials.export_to_xml('materials_ref.xml')
+        pwr_model.geometry.export_to_xml('geometry_ref.xml')
+
+        # now write and read a model.xml file
+        pwr_model.export_to_xml(separate_xmls=False)
+        new_model = openmc.Model.from_xml(separate_xmls=False)
+
+        # make sure we can also export this again to separate
+        # XML files
+        new_model.export_to_xml(separate_xmls=True)
\ No newline at end of file