From 977ea5b602fe7b433b5ecf8b1fc02f7223d50e54 Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Thu, 23 Apr 2020 09:23:34 -0500
Subject: [PATCH] Changes in filter_mesh.cpp from PullRequest Inc. review

---
 src/cross_sections.cpp      | 3 +++
 src/tallies/filter_mesh.cpp | 8 +++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/cross_sections.cpp b/src/cross_sections.cpp
index 737d2a4aab..1d36b5cff4 100644
--- a/src/cross_sections.cpp
+++ b/src/cross_sections.cpp
@@ -282,6 +282,7 @@ read_ce_cross_sections(const std::vector<std::vector<double>>& nuc_temps,
     }
   }
 
+  // Perform final tasks -- reading S(a,b) tables, normalizing densities
   for (auto& mat : model::materials) {
     for (const auto& table : mat->thermal_tables_) {
       // Get name of S(a,b) table
@@ -408,6 +409,8 @@ void read_ce_cross_sections_xml()
   } else {
     // If no directory is listed in cross_sections.xml, by default select the
     // directory in which the cross_sections.xml file resides
+
+    // TODO: Use std::filesystem functionality when C++17 is adopted
     auto pos = filename.rfind("/");
     if (pos == std::string::npos) {
       // no '/' found, probably a Windows directory
diff --git a/src/tallies/filter_mesh.cpp b/src/tallies/filter_mesh.cpp
index d2a240bcf1..60ab318cc1 100644
--- a/src/tallies/filter_mesh.cpp
+++ b/src/tallies/filter_mesh.cpp
@@ -1,6 +1,7 @@
 #include "openmc/tallies/filter_mesh.h"
 
 #include <fmt/core.h>
+#include <gsl/gsl>
 
 #include "openmc/capi.h"
 #include "openmc/constants.h"
@@ -54,7 +55,7 @@ MeshFilter::to_statepoint(hid_t filter_group) const
 std::string
 MeshFilter::text_label(int bin) const
 {
-  auto& mesh = *model::meshes[mesh_];
+  auto& mesh = *model::meshes.at(mesh_);
   return mesh.bin_label(bin);
 }
 
@@ -72,6 +73,11 @@ MeshFilter::set_mesh(int32_t mesh)
 extern "C" int
 openmc_mesh_filter_get_mesh(int32_t index, int32_t* index_mesh)
 {
+  if (!index_mesh) {
+    set_errmsg("Mesh index argument is a null pointer.");
+    return OPENMC_E_INVALID_ARGUMENT;
+  }
+
   // Make sure this is a valid index to an allocated filter.
   if (int err = verify_filter(index)) return err;