From 32d041ec90deb4e2bffd9714cba7661d32a05328 Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Wed, 20 Oct 2021 10:48:27 -0500
Subject: [PATCH] Fix bug for when local cross_sections.xml is specified

---
 src/cross_sections.cpp | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/cross_sections.cpp b/src/cross_sections.cpp
index 9156bdc90..afb0a1f36 100644
--- a/src/cross_sections.cpp
+++ b/src/cross_sections.cpp
@@ -76,8 +76,10 @@ Library::Library(pugi::xml_node node, const std::string& directory)
     path_ = path;
   } else if (ends_with(directory, "/")) {
     path_ = directory + path;
-  } else {
+  } else if (!directory.empty()) {
     path_ = directory + "/" + path;
+  } else {
+    path_ = path;
   }
 
   if (!file_exists(path_)) {
@@ -135,6 +137,13 @@ void read_cross_sections_xml()
     }
   } else {
     settings::path_cross_sections = get_node_value(root, "cross_sections");
+
+    // If no '/' found, the file is probably in the input directory
+    auto pos = settings::path_cross_sections.rfind("/");
+    if (pos == std::string::npos && !settings::path_input.empty()) {
+      settings::path_cross_sections =
+        settings::path_input + "/" + settings::path_cross_sections;
+    }
   }
 
   // Now that the cross_sections.xml or mgxs.h5 has been located, read it in
@@ -295,10 +304,12 @@ void read_ce_cross_sections_xml()
     // 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
-      pos = filename.rfind("\\");
+      // No '\\' found, so the file must be in the same directory as
+      // materials.xml
+      directory = settings::path_input;
+    } else {
+      directory = filename.substr(0, pos);
     }
-    directory = filename.substr(0, pos);
   }
 
   for (const auto& node_library : root.children("library")) {