Fix T66913: undo after frame-change doesn't refresh properly

Use the ID.recalc flag to detect when updates after frame-change is
needed. Since comparing the last calculated frame doesn't take undo into
account (see code-comment for details).

`ID_RECALC_AUDIO_SEEK` has been renamed to `ID_RECALC_FRAME_CHANGE`
since this is not only related to audio however internally this flag is
still categorized in `NodeType::AUDIO`.

Reviewed By: sergey

Ref D13942

2 files changed, 11 insertions, 3 deletions

diff --git a/source/blender/depsgraph/intern/depsgraph_eval.cc b/source/blender/depsgraph/intern/depsgraph_eval.cc
index 7952f27507f..ae94fbcfdb8 100644
--- a/source/blender/depsgraph/intern/depsgraph_eval.cc
+++ b/source/blender/depsgraph/intern/depsgraph_eval.cc
@@ -72,6 +72,14 @@ void DEG_evaluate_on_refresh(Depsgraph *graph)
     deg_graph->frame = frame;
     deg_graph->ctime = ctime;
   }
+  else if (scene->id.recalc & ID_RECALC_FRAME_CHANGE) {
+    /* Comparing depsgraph & scene frame fails in the case of undo,
+     * since the undo state is stored before updates from the frame change have been applied.
+     * In this case reading back the undo state will behave as if no updates on frame change
+     * is needed as the #Depsgraph.ctime & frame will match the values in the input scene.
+     * Use #ID_RECALC_FRAME_CHANGE to detect that recalculation is necessary. see: T66913. */
+    deg_graph->tag_time_source();
+  }
 
   deg_flush_updates_and_refresh(deg_graph);
 }
diff --git a/source/blender/depsgraph/intern/depsgraph_tag.cc b/source/blender/depsgraph/intern/depsgraph_tag.cc
index 6614509f860..11074b5bf72 100644
--- a/source/blender/depsgraph/intern/depsgraph_tag.cc
+++ b/source/blender/depsgraph/intern/depsgraph_tag.cc
@@ -211,7 +211,7 @@ void depsgraph_tag_to_component_opcode(const ID *id,
     case ID_RECALC_SEQUENCER_STRIPS:
       *component_type = NodeType::SEQUENCER;
       break;
-    case ID_RECALC_AUDIO_SEEK:
+    case ID_RECALC_FRAME_CHANGE:
     case ID_RECALC_AUDIO_FPS:
     case ID_RECALC_AUDIO_VOLUME:
     case ID_RECALC_AUDIO_MUTE:
@@ -737,8 +737,8 @@ const char *DEG_update_tag_as_string(IDRecalcFlag flag)
       return "EDITORS";
     case ID_RECALC_SEQUENCER_STRIPS:
       return "SEQUENCER_STRIPS";
-    case ID_RECALC_AUDIO_SEEK:
-      return "AUDIO_SEEK";
+    case ID_RECALC_FRAME_CHANGE:
+      return "FRAME_CHANGE";
     case ID_RECALC_AUDIO_FPS:
       return "AUDIO_FPS";
     case ID_RECALC_AUDIO_VOLUME: