4 files changed, 45 insertions, 2 deletions

diff --git a/source/blender/depsgraph/DEG_depsgraph.h b/source/blender/depsgraph/DEG_depsgraph.h
index d5a93d21b99..c94a8876ab0 100644
--- a/source/blender/depsgraph/DEG_depsgraph.h
+++ b/source/blender/depsgraph/DEG_depsgraph.h
@@ -92,6 +92,11 @@ Depsgraph *DEG_graph_new(struct Main *bmain,
                          struct ViewLayer *view_layer,
                          eEvaluationMode mode);
 
+void DEG_graph_replace_owners(struct Depsgraph *depsgraph,
+                              struct Main *bmain,
+                              struct Scene *scene,
+                              struct ViewLayer *view_layer);
+
 /* Free Depsgraph itself and all its data */
 void DEG_graph_free(Depsgraph *graph);
 
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
index 6791125d1e9..27d6db6a58f 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
@@ -2127,9 +2127,20 @@ void DepsgraphRelationBuilder::build_object_data_geometry_datablock(ID *obdata)
       /* Layer parenting need react to the parent object transformation. */
       LISTBASE_FOREACH (bGPDlayer *, gpl, &gpd->layers) {
         if (gpl->parent != NULL) {
-          ComponentKey transform_key(&gpl->parent->id, NodeType::TRANSFORM);
           ComponentKey gpd_geom_key(&gpd->id, NodeType::GEOMETRY);
-          add_relation(transform_key, gpd_geom_key, "GPencil Parent Layer");
+
+          if (gpl->partype == PARBONE) {
+            ComponentKey bone_key(&gpl->parent->id, NodeType::BONE, gpl->parsubstr);
+            OperationKey armature_key(
+                &gpl->parent->id, NodeType::TRANSFORM, OperationCode::TRANSFORM_FINAL);
+
+            add_relation(bone_key, gpd_geom_key, "Bone Parent");
+            add_relation(armature_key, gpd_geom_key, "Armature Parent");
+          }
+          else {
+            ComponentKey transform_key(&gpl->parent->id, NodeType::TRANSFORM);
+            add_relation(transform_key, gpd_geom_key, "GPencil Parent Layer");
+          }
         }
       }
       break;
diff --git a/source/blender/depsgraph/intern/depsgraph.cc b/source/blender/depsgraph/intern/depsgraph.cc
index ce6797939b5..a19a2958f28 100644
--- a/source/blender/depsgraph/intern/depsgraph.cc
+++ b/source/blender/depsgraph/intern/depsgraph.cc
@@ -285,6 +285,29 @@ Depsgraph *DEG_graph_new(Main *bmain, Scene *scene, ViewLayer *view_layer, eEval
   return reinterpret_cast<Depsgraph *>(deg_depsgraph);
 }
 
+/* Replace the "owner" pointers (currently Main/Scene/ViewLayer) of this depsgraph.
+ * Used during undo steps when we do want to re-use the old depsgraph data as much as possible. */
+void DEG_graph_replace_owners(struct Depsgraph *depsgraph,
+                              Main *bmain,
+                              Scene *scene,
+                              ViewLayer *view_layer)
+{
+  DEG::Depsgraph *deg_graph = reinterpret_cast<DEG::Depsgraph *>(depsgraph);
+
+  const bool do_update_register = deg_graph->bmain != bmain;
+  if (do_update_register && deg_graph->bmain != NULL) {
+    DEG::unregister_graph(deg_graph);
+  }
+
+  deg_graph->bmain = bmain;
+  deg_graph->scene = scene;
+  deg_graph->view_layer = view_layer;
+
+  if (do_update_register) {
+    DEG::register_graph(deg_graph);
+  }
+}
+
 /* Free graph's contents and graph itself */
 void DEG_graph_free(Depsgraph *graph)
 {
diff --git a/source/blender/depsgraph/intern/depsgraph_tag.cc b/source/blender/depsgraph/intern/depsgraph_tag.cc
index b019c079dab..8decb9f6b87 100644
--- a/source/blender/depsgraph/intern/depsgraph_tag.cc
+++ b/source/blender/depsgraph/intern/depsgraph_tag.cc
@@ -814,12 +814,16 @@ void DEG_ids_check_recalc(
 
 static void deg_graph_clear_id_recalc_flags(ID *id)
 {
+  /* Keep incremental track of used recalc flags, to get proper update when undoing. */
+  id->recalc_undo_accumulated |= id->recalc;
   id->recalc &= ~ID_RECALC_ALL;
   bNodeTree *ntree = ntreeFromID(id);
   /* Clear embedded node trees too. */
   if (ntree) {
+    ntree->id.recalc_undo_accumulated |= ntree->id.recalc;
     ntree->id.recalc &= ~ID_RECALC_ALL;
   }
+  /* XXX And what about scene's master collection here? */
 }
 
 void DEG_ids_clear_recalc(Main *UNUSED(bmain), Depsgraph *depsgraph)