From ff0d256e9779efa1aef15cfe24aeab0c88fd4337 Mon Sep 17 00:00:00 2001
From: Roland Conybeare <rconybeare@gmail.com>
Date: Wed, 13 May 2026 08:14:58 -0400
Subject: [PATCH] xo-gc: address some coverage loose ends

---
 xo-gc/utest/GCObjectStore.test.cpp | 15 +++++++++++++++
 xo-object2/src/object2/DList.cpp   |  2 +-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/xo-gc/utest/GCObjectStore.test.cpp b/xo-gc/utest/GCObjectStore.test.cpp
index 6c7ed42b..3c82f922 100644
--- a/xo-gc/utest/GCObjectStore.test.cpp
+++ b/xo-gc/utest/GCObjectStore.test.cpp
@@ -5,6 +5,7 @@
 
 #include "GcosTestutil.hpp"
 #include <xo/gc/GCObjectStore.hpp>
+#include <xo/gc/GCObjectStoreVisitor.hpp>
 #include <xo/gc/X1VerifyStats.hpp>
 #include <xo/object2/ListOps.hpp>
 #include <xo/object2/List.hpp>
@@ -32,6 +33,8 @@ namespace ut {
     using xo::mm::X1VerifyStats;
     using xo::mm::AGCObject;
     using xo::mm::AGCObjectVisitor;
+    using xo::mm::AGCObjectVisitor;
+    using xo::mm::DGCObjectStoreVisitor;
     using xo::mm::Generation;
     using xo::mm::Role;
     using xo::mm::object_age;
@@ -381,6 +384,18 @@ namespace ut {
                     report_gco.reset();
                     fixture.report_mm()->clear();
                 }
+
+                // operate visitor (loose ends revealed by coverage).
+                // mostly tested by moving objects
+                {
+                    DGCObjectStoreVisitor visitor(&gcos, Generation::g0());
+                    auto visitor_fop = obj<AGCObjectVisitor,DGCObjectStoreVisitor>(&visitor);
+
+                    REQUIRE(!visitor_fop.iface()->_has_null_vptr());
+                    REQUIRE(visitor_fop._typeseq() == typeseq::id<DGCObjectStoreVisitor>());
+
+                    visitor_fop._drop();
+                }
             }
         } /* loop over test cases */
     } /* TEST_CASE(GCObjectStore-1) */
diff --git a/xo-object2/src/object2/DList.cpp b/xo-object2/src/object2/DList.cpp
index 98c82a09..54315823 100644
--- a/xo-object2/src/object2/DList.cpp
+++ b/xo-object2/src/object2/DList.cpp
@@ -143,7 +143,7 @@ namespace xo {
         {
             scope log(XO_DEBUG(true), xtag("gc.data", gc.data_));
 
-            xo::mm::mm_do_assign(gc, this, &head_, rhs);
+            gc.assign_member(this, &head_, rhs);
         }
 
         void