Fix stack overflow in ifc-printer when parsing self-referential types

.gitignore

@@ -1,4 +1,5 @@
 /build/
+/build-test/
 /prefix/
 /linux-build/
 /CMakeUserPresets.json

include/ifc/dom/node.hxx

@@ -184,6 +184,8 @@ namespace ifc::util {
         std::string ref(const symbolic::Identity<NameIndex>& id);
 
         std::set<NodeKey> referenced_nodes;
+        // Track indices currently being processed to detect cycles
+        std::set<TypeIndex> processing_types;
 
     private:
         using NodeMap = std::map<NodeKey, Node>;

src/ifc-dom/types.cxx

@@ -159,9 +159,19 @@ namespace ifc::util {
 
     std::string get_string_if_possible(Loader& ctx, TypeIndex index)
     {
-        if (not null(index))
-            return ctx.reader.visit(index, TypeTranslator{ctx});
-        return "no-type";
+        if (null(index))
+            return "no-type";
+
+        // Check for cycles to prevent infinite recursion
+        if (ctx.processing_types.find(index) != ctx.processing_types.end()) {
+            return "..." + to_string(index);  // Return a reference to break the cycle
+        }
+
+        // Track this index while processing
+        ctx.processing_types.insert(index);
+        auto result = ctx.reader.visit(index, TypeTranslator{ctx});
+        ctx.processing_types.erase(index);
+        return result;
     }
 
     // Load types as full blown nodes.