Use weak pointer for MirrorModifierData mirror_ob to avoid memory leak

code/AssetLib/Blender/BlenderModifier.cpp

@@ -153,6 +153,7 @@ void BlenderModifier_Mirror ::DoIt(aiNode &out, ConversionData &conv_data, const
     // hijacking the ABI, see the big note in BlenderModifierShowcase::ApplyModifiers()
     const MirrorModifierData &mir = static_cast<const MirrorModifierData &>(orig_modifier);
     ai_assert(mir.modifier.type == ModifierData::eModifierType_Mirror);
+    std::shared_ptr<Object> mirror_ob = mir.mirror_ob.lock();
 
     conv_data.meshes->reserve(conv_data.meshes->size() + out.mNumMeshes);
 
@@ -167,8 +168,8 @@ void BlenderModifier_Mirror ::DoIt(aiNode &out, ConversionData &conv_data, const
         const float ys = mir.flag & MirrorModifierData::Flags_AXIS_Y ? -1.f : 1.f;
         const float zs = mir.flag & MirrorModifierData::Flags_AXIS_Z ? -1.f : 1.f;
 
-        if (mir.mirror_ob) {
-            const aiVector3D center(mir.mirror_ob->obmat[3][0], mir.mirror_ob->obmat[3][1], mir.mirror_ob->obmat[3][2]);
+        if (mirror_ob) {
+            const aiVector3D center(mirror_ob->obmat[3][0], mirror_ob->obmat[3][1], mirror_ob->obmat[3][2]);
             for (unsigned int j = 0; j < mesh->mNumVertices; ++j) {
                 aiVector3D &v = mesh->mVertices[j];
 

code/AssetLib/Blender/BlenderScene.cpp

@@ -772,7 +772,9 @@ void Structure ::Convert<MirrorModifierData>(
     ReadField<ErrorPolicy_Igno>(dest.axis, "axis", db);
     ReadField<ErrorPolicy_Igno>(dest.flag, "flag", db);
     ReadField<ErrorPolicy_Igno>(dest.tolerance, "tolerance", db);
-    ReadFieldPtr<ErrorPolicy_Igno>(dest.mirror_ob, "*mirror_ob", db);
+    std::shared_ptr<Object> mirror_ob;
+    ReadFieldPtr<ErrorPolicy_Igno>(mirror_ob, "*mirror_ob", db);
+    dest.mirror_ob = mirror_ob;
 
     db.reader->IncPtr(size);
 }

code/AssetLib/Blender/BlenderScene.h

@@ -690,7 +690,7 @@ struct MirrorModifierData : SharedModifierData {
 
     short axis, flag;
     float tolerance;
-    std::shared_ptr<Object> mirror_ob;
+    std::weak_ptr<Object> mirror_ob;
 };
 
 // -------------------------------------------------------------------------------