From 12318fbfc2a52785dd16ee65c0297fbd019af470 Mon Sep 17 00:00:00 2001
From: Thomas Krijnen <t.krijnen@gmail.com>
Date: Thu, 5 Sep 2024 14:38:21 +0200
Subject: [PATCH] Handle storage of nullptr as a proper Blank type in variant
 #5308

---
 src/ifcparse/IfcParse.cpp | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/ifcparse/IfcParse.cpp b/src/ifcparse/IfcParse.cpp
index 298295e6a2..0ea64c2f78 100644
--- a/src/ifcparse/IfcParse.cpp
+++ b/src/ifcparse/IfcParse.cpp
@@ -1149,7 +1149,15 @@ void IfcUtil::IfcBaseClass::set_attribute_value(size_t i, const T& t) {
         apply_individual_instance_visitor(current_attribute, (int) i).apply(visitor);
     }
 
-    data_.storage_.set(i, t);
+    if constexpr (std::is_pointer_v<T>) {
+        if (t) {
+            data_.storage_.set(i, t);
+        } else {
+            data_.storage_.set(i, Blank{});
+        }
+    } else {
+        data_.storage_.set(i, t);
+    }
     auto new_attribute = data_.get_attribute_value(i);
 
     if (file_ != nullptr) {