[Bf-blender-cvs] [6f9828289f3] blender-v3.1-release: Fix T95356: Crash in armature edit mode and certain condition

[Sergey Sharybin]

Commit: 6f9828289f397228c6cab6f352fb4a84a65da22a
Author: Sergey Sharybin
Date:   Mon Jan 31 17:37:07 2022 +0100
Branches: blender-v3.1-release
https://developer.blender.org/rB6f9828289f397228c6cab6f352fb4a84a65da22a

Fix T95356: Crash in armature edit mode and certain condition

Blender would have crashed when renaming bone in Edit Mode, Saving, and
than selecting/deselecting.

Caused by a mistake in the 0f89bcdbebf5: can not "short-circuit" the
CoW update if it was explicitly requested.

Safest for now solution seems to be to store whether the CoW component
has been explicitly tagged, so that the following configuration can be
supported:

    DEG_id_tag_update(id, ID_RECALC_GEOMETRY);
    DEG_id_tag_update(id, ID_RECALC_COPY_ON_WRITE);

Differential Revision: https://developer.blender.org/D13966

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

M	source/blender/depsgraph/intern/depsgraph_tag.cc
M	source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
M	source/blender/depsgraph/intern/node/deg_node_id.h

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

diff --git a/source/blender/depsgraph/intern/depsgraph_tag.cc b/source/blender/depsgraph/intern/depsgraph_tag.cc
index 4bc9e0d2d14..6614509f860 100644
--- a/source/blender/depsgraph/intern/depsgraph_tag.cc
+++ b/source/blender/depsgraph/intern/depsgraph_tag.cc
@@ -284,6 +284,7 @@ void depsgraph_tag_component(Depsgraph *graph,
    * here. */
   if (component_node == nullptr) {
     if (component_type == NodeType::ANIMATION) {
+      id_node->is_cow_explicitly_tagged = true;
       depsgraph_id_tag_copy_on_write(graph, id_node, update_source);
     }
     return;
@@ -301,6 +302,9 @@ void depsgraph_tag_component(Depsgraph *graph,
   if (component_node->need_tag_cow_before_update()) {
     depsgraph_id_tag_copy_on_write(graph, id_node, update_source);
   }
+  if (component_type == NodeType::COPY_ON_WRITE) {
+    id_node->is_cow_explicitly_tagged = true;
+  }
 }
 
 /* This is a tag compatibility with legacy code.
@@ -888,6 +892,7 @@ void DEG_ids_clear_recalc(Depsgraph *depsgraph, const bool backup)
      * correctly when there are multiple depsgraph with others still using
      * the recalc flag. */
     id_node->is_user_modified = false;
+    id_node->is_cow_explicitly_tagged = false;
     deg_graph_clear_id_recalc_flags(id_node->id_cow);
     if (deg_graph->is_active) {
       deg_graph_clear_id_recalc_flags(id_node->id_orig);
diff --git a/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc b/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
index 851d0bcf000..8a3c5c5b776 100644
--- a/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
+++ b/source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
@@ -904,7 +904,7 @@ ID *deg_update_copy_on_write_datablock(const Depsgraph *depsgraph, const IDNode
    * modifiers.
    *
    * TODO: Investigate modes besides edit-mode. */
-  if (check_datablock_expanded(id_cow)) {
+  if (check_datablock_expanded(id_cow) && !id_node->is_cow_explicitly_tagged) {
     const ID_Type id_type = GS(id_orig->name);
     if (OB_DATA_SUPPORT_EDITMODE(id_type) && BKE_object_data_is_in_editmode(id_orig)) {
       /* Make sure pointers in the edit mode data are updated in the copy.
diff --git a/source/blender/depsgraph/intern/node/deg_node_id.h b/source/blender/depsgraph/intern/node/deg_node_id.h
index 257e42b8e67..f18c44b6332 100644
--- a/source/blender/depsgraph/intern/node/deg_node_id.h
+++ b/source/blender/depsgraph/intern/node/deg_node_id.h
@@ -121,6 +121,9 @@ struct IDNode : public Node {
   /* Accumulated flag from operation. Is initialized and used during updates flush. */
   bool is_user_modified;
 
+  /* Copy-on-Write component has been explicitly tagged for update. */
+  bool is_cow_explicitly_tagged;
+
   /* Accumulate recalc flags from multiple update passes. */
   int id_cow_recalc_backup;