From de666e3291a4804fa207ee1c884ddcbb1911998d Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Tue, 6 Nov 2018 09:52:18 -0600
Subject: [PATCH] Make sure MG materials get put in libraries

---
 include/openmc/cross_sections.h |  1 +
 src/hdf5_interface.cpp          |  2 +-
 src/input_xml.F90               | 12 ------------
 src/mgxs_interface.cpp          | 15 +++++++++++++++
 4 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/include/openmc/cross_sections.h b/include/openmc/cross_sections.h
index 2b7a94f805..72e89692c4 100644
--- a/include/openmc/cross_sections.h
+++ b/include/openmc/cross_sections.h
@@ -21,6 +21,7 @@ public:
   };
 
   // Constructors
+  Library() { };
   Library(pugi::xml_node node, const std::string& directory);
 
   // Comparison operator (for using in map)
diff --git a/src/hdf5_interface.cpp b/src/hdf5_interface.cpp
index 4b0aedd0ae..865b6eb202 100644
--- a/src/hdf5_interface.cpp
+++ b/src/hdf5_interface.cpp
@@ -362,7 +362,7 @@ member_names(hid_t group_id, H5O_type_t type)
     char buffer[size];
     H5Lget_name_by_idx(group_id, ".", H5_INDEX_NAME, H5_ITER_INC, i,
                        buffer, size, H5P_DEFAULT);
-    names.emplace_back(&buffer[0], size);
+    names.emplace_back(&buffer[0]);
   }
   return names;
 }
diff --git a/src/input_xml.F90 b/src/input_xml.F90
index 06beee34e1..8dc7452037 100644
--- a/src/input_xml.F90
+++ b/src/input_xml.F90
@@ -1907,10 +1907,8 @@ contains
 
   subroutine read_mg_cross_sections_header() bind(C)
     integer :: i           ! loop index
-    integer :: n_libraries
     logical :: file_exists ! does mgxs.h5 exist?
     integer(HID_T) :: file_id
-    character(len=MAX_WORD_LEN), allocatable :: names(:)
     character(kind=C_CHAR), pointer :: string(:)
 
     interface
@@ -1984,16 +1982,6 @@ contains
     call set_particle_energy_bounds(NEUTRON, energy_min(NEUTRON), &
          energy_max(NEUTRON))
 
-    ! Get the datasets present in the library
-    call get_groups(file_id, names)
-    n_libraries = size(names)
-
-    ! Allocate libraries array
-    if (n_libraries == 0) then
-      call fatal_error("At least one MGXS data set must be present in &
-                       &mgxs library file!")
-    end if
-
     ! Close MGXS HDF5 file
     call file_close(file_id)
 
diff --git a/src/mgxs_interface.cpp b/src/mgxs_interface.cpp
index 0729e466c7..9b320c4e1c 100644
--- a/src/mgxs_interface.cpp
+++ b/src/mgxs_interface.cpp
@@ -2,6 +2,7 @@
 
 #include <string>
 
+#include "openmc/cross_sections.h"
 #include "openmc/error.h"
 #include "openmc/math_functions.h"
 
@@ -109,6 +110,20 @@ void read_mg_cross_sections_header_c(hid_t file_id)
   for (int i = 0; i < energy_bins.size() - 1; ++i) {
     energy_bin_avg.push_back(0.5*(energy_bins[i] + energy_bins[i+1]));
   }
+
+  // Add entries into libraries for MG data
+  auto names = group_names(file_id);
+  if (names.empty()) {
+    fatal_error("At least one MGXS data set must be present in mgxs "
+      "library file!");
+  }
+
+  for (auto& name : names) {
+    Library lib {};
+    lib.type_ = Library::Type::neutron;
+    lib.materials_.push_back(name);
+    libraries.push_back(lib);
+  }
 }
 
 //==============================================================================