[Bf-blender-cvs] [d8841d0aa34] master: Fix T100394: Regression: Duplicating a modifier causes a crash

[Sergey Sharybin]

Commit: d8841d0aa341e05c8cb9559b116b7e2a9ec11882
Author: Sergey Sharybin
Date:   Mon Aug 15 11:54:21 2022 +0200
Branches: master
https://developer.blender.org/rBd8841d0aa341e05c8cb9559b116b7e2a9ec11882

Fix T100394: Regression: Duplicating a modifier causes a crash

Need to update relations when modifiers are added or removed
since those create nodes in the dependency graph.

Added an assert statement to point at possible culprit so
that issues can be fixed more quickly.

===================================================================

M	source/blender/depsgraph/intern/eval/deg_eval_visibility.cc
M	source/blender/editors/object/object_modifier.cc

===================================================================

diff --git a/source/blender/depsgraph/intern/eval/deg_eval_visibility.cc b/source/blender/depsgraph/intern/eval/deg_eval_visibility.cc
index 7b6aec0a73c..a056ba1dfa7 100644
--- a/source/blender/depsgraph/intern/eval/deg_eval_visibility.cc
+++ b/source/blender/depsgraph/intern/eval/deg_eval_visibility.cc
@@ -69,6 +69,10 @@ void deg_evaluate_object_modifiers_mode_node_visibility(::Depsgraph *depsgraph,
     OperationNode *modifier_node = geometry_component->find_operation(OperationCode::MODIFIER,
                                                                       modifier->name);
 
+    BLI_assert_msg(modifier_node != nullptr,
+                   "Modifier node in depsgraph is not found. Likely due to missing "
+                   "DEG_relations_tag_update().");
+
     const bool modifier_enabled = modifier->mode & modifier_mode;
     const int mute_flag = modifier_enabled ? 0 : DEPSOP_FLAG_MUTE;
     if ((modifier_node->flag & DEPSOP_FLAG_MUTE) != mute_flag) {
diff --git a/source/blender/editors/object/object_modifier.cc b/source/blender/editors/object/object_modifier.cc
index e7cfcf48fd3..010a01f9d30 100644
--- a/source/blender/editors/object/object_modifier.cc
+++ b/source/blender/editors/object/object_modifier.cc
@@ -486,6 +486,9 @@ bool ED_object_modifier_move_to_index(ReportList *reports,
     }
   }
 
+  /* NOTE: Dependency graph only uses modifier nodes for visibility updates, and exact order of
+   * modifier nodes in the graph does not matter. */
+
   DEG_id_tag_update(&ob->id, ID_RECALC_GEOMETRY);
   WM_main_add_notifier(NC_OBJECT | ND_MODIFIER, ob);
 
@@ -1668,6 +1671,7 @@ static int modifier_copy_exec(bContext *C, wmOperator *op)
   }
 
   DEG_id_tag_update(&ob->id, ID_RECALC_GEOMETRY);
+  DEG_relations_tag_update(bmain);
   WM_event_add_notifier(C, NC_OBJECT | ND_MODIFIER, ob);
 
   return OPERATOR_FINISHED;