Enable new undo code by default.

Note that given how experimental is working currently, I had to rename
and inverse the effect of the experimental undo flag, which will now
instead activate legacy code when set.

4 files changed, 7 insertions, 7 deletions

diff --git a/release/scripts/startup/bl_ui/space_userpref.py b/release/scripts/startup/bl_ui/space_userpref.py
index 414444a6ee5..179b3612a62 100644
--- a/release/scripts/startup/bl_ui/space_userpref.py
+++ b/release/scripts/startup/bl_ui/space_userpref.py
@@ -2167,7 +2167,7 @@ class USERPREF_PT_experimental_system(ExperimentalPanel, Panel):
     def draw(self, context):
         self._draw_items(
             context, (
-                ({"property": "use_undo_speedup"}, "T60695"),
+                ({"property": "use_undo_legacy"}, "T60695"),
             ),
         )
 
diff --git a/source/blender/editors/undo/memfile_undo.c b/source/blender/editors/undo/memfile_undo.c
index 9954cf85157..f22e18de7a1 100644
--- a/source/blender/editors/undo/memfile_undo.c
+++ b/source/blender/editors/undo/memfile_undo.c
@@ -147,7 +147,7 @@ static void memfile_undosys_step_decode(struct bContext *C,
 
   bool use_old_bmain_data = true;
 
-  if (!U.experimental.use_undo_speedup) {
+  if (USER_EXPERIMENTAL_TEST(&U, use_undo_legacy)) {
     use_old_bmain_data = false;
   }
   else if (undo_direction > 0) {
diff --git a/source/blender/makesdna/DNA_userdef_types.h b/source/blender/makesdna/DNA_userdef_types.h
index e8f4cae573a..7a09059e344 100644
--- a/source/blender/makesdna/DNA_userdef_types.h
+++ b/source/blender/makesdna/DNA_userdef_types.h
@@ -618,7 +618,7 @@ typedef struct UserDef_FileSpaceData {
 } UserDef_FileSpaceData;
 
 typedef struct UserDef_Experimental {
-  char use_undo_speedup;
+  char use_undo_legacy;
   char use_menu_search;
   /** `makesdna` does not allow empty structs. */
   char _pad0[6];
diff --git a/source/blender/makesrna/intern/rna_userdef.c b/source/blender/makesrna/intern/rna_userdef.c
index 514d7428ff8..c08a95d7e16 100644
--- a/source/blender/makesrna/intern/rna_userdef.c
+++ b/source/blender/makesrna/intern/rna_userdef.c
@@ -6057,12 +6057,12 @@ static void rna_def_userdef_experimental(BlenderRNA *brna)
   RNA_def_struct_clear_flag(srna, STRUCT_UNDO);
   RNA_def_struct_ui_text(srna, "Experimental", "Experimental features");
 
-  prop = RNA_def_property(srna, "use_undo_speedup", PROP_BOOLEAN, PROP_NONE);
-  RNA_def_property_boolean_sdna(prop, NULL, "use_undo_speedup", 1);
+  prop = RNA_def_property(srna, "use_undo_legacy", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "use_undo_legacy", 1);
   RNA_def_property_ui_text(
       prop,
-      "Undo Speedup",
-      "Use new undo speedup (WARNING: can lead to crashes and serious .blend file corruption)");
+      "Undo Legacy",
+      "Use legacy undo (slower than the new default one, but may be more stable in some cases)");
 
   prop = RNA_def_property(srna, "use_menu_search", PROP_BOOLEAN, PROP_NONE);
   RNA_def_property_boolean_sdna(prop, NULL, "use_menu_search", 1);