source/blender/editors/include/ED_undo.hh

@@ -129,6 +129,7 @@ void ED_undosys_type_free();
 
 /* `memfile_undo.cc` */
 
+MemFile *ED_undosys_stack_memfile_get_if_active(UndoStack *ustack);
 /**
  * If the last undo step is a memfile one, find the first #MemFileChunk matching given ID
  * (using its session UUID), and tag it as "changed in the future".

source/blender/editors/undo/memfile_undo.cc

@@ -345,6 +345,27 @@ void ED_memfile_undosys_type(UndoType *ut)
 /** \name Utilities
  * \{ */
 
+/**
+ * Ideally we wouldn't need to export global undo internals,
+ * there are some cases where it's needed though.
+ */
+static MemFile *ed_undosys_step_get_memfile(UndoStep *us_p)
+{
+  MemFileUndoStep *us = (MemFileUndoStep *)us_p;
+  return &us->data->memfile;
+}
+
+MemFile *ED_undosys_stack_memfile_get_if_active(UndoStack *ustack)
+{
+  if (!ustack->step_active) {
+    return nullptr;
+  }
+  if (ustack->step_active->type != BKE_UNDOSYS_TYPE_MEMFILE) {
+    return nullptr;
+  }
+  return ed_undosys_step_get_memfile(ustack->step_active);
+}
+
 void ED_undosys_stack_memfile_id_changed_tag(UndoStack *ustack, ID *id)
 {
   UndoStep *us = ustack->step_active;

source/blender/windowmanager/intern/wm_files.cc

@@ -2115,9 +2115,12 @@ static bool wm_autosave_write_try(Main *bmain, wmWindowManager *wm)
 
   wm_autosave_location(filepath);
 
-  if (MemFile *memfile = ED_undosys_stack_memfile_get_if_active(wm->undo_stack)) {
-    /* Fast save of last undo-buffer, now with UI. */
-    BLO_memfile_write_file(memfile, filepath);
+  /* Technically, we could always just save here, but that would cause performance regressions
+   * compared to when the #MemFile undo step was used for saving undo-steps. So for now just skip
+   * auto-save when we are in a mode where auto-save wouldn't have worked previously anyway. This
+   * check can be removed once the performance regressions have been solved. */
+  if (ED_undosys_stack_memfile_get_if_active(wm->undo_stack) != nullptr) {
+    WM_autosave_write(wm, bmain);
     return true;
   }
   if ((U.uiflag & USER_GLOBALUNDO) == 0) {
@@ -2184,17 +2187,14 @@ void wm_autosave_timer(Main *bmain, wmWindowManager *wm, wmTimer * /*wt*/)
 {
   wm_autosave_timer_end(wm);
 
-  /* Time to wait until the next attempt to autosave if it is disabled right now. */
-  const double try_again_time_step = 0.01;
-
   /* If a modal operator is running, don't autosave because we might not be in
-   * a valid state to save. */
+   * a valid state to save. But try again in 10ms. */
   LISTBASE_FOREACH (wmWindow *, win, &wm->windows) {
     LISTBASE_FOREACH (wmEventHandler *, handler_base, &win->modalhandlers) {
       if (handler_base->type == WM_HANDLER_TYPE_OP) {
         wmEventHandler_Op *handler = (wmEventHandler_Op *)handler_base;
         if (handler->op) {
-          wm_autosave_timer_begin_ex(wm, try_again_time_step);
+          wm_autosave_timer_begin_ex(wm, 0.01);
           return;
         }
       }

source/blender/windowmanager/intern/wm_init_exit.cc

@@ -471,26 +471,19 @@ void WM_exit_ex(bContext *C, const bool do_python_exit, const bool do_user_exit_
   /* NOTE: same code copied in `wm_files.cc`. */
   if (C && wm) {
     if (do_user_exit_actions) {
-      /* save the undo state as quit.blend */
+      /* Save quit.blend. */
       Main *bmain = CTX_data_main(C);
       char filepath[FILE_MAX];
-      BLI_path_join(filepath, sizeof(filepath), BKE_tempdir_base(), BLENDER_QUIT_FILE);
-      MemFile *undo_memfile = wm->undo_stack ?
-                                  ED_undosys_stack_memfile_get_if_active(wm->undo_stack) :
-                                  nullptr;
-      /* When true, the `undo_memfile` doesn't contain all information necessary
-       * for writing and up to date blend file. */
-      const bool is_memfile_outdated = ED_editors_flush_edits(bmain);
+      const int fileflags = G.fileflags & ~G_FILE_COMPRESS;
 
-      if (undo_memfile && !is_memfile_outdated) {
-        BLO_memfile_write_file(undo_memfile, filepath);
+      BLI_path_join(filepath, sizeof(filepath), BKE_tempdir_base(), BLENDER_QUIT_FILE);
+
+      ED_editors_flush_edits(bmain);
+
+      BlendFileWriteParams blend_file_write_params{};
+      if (BLO_write_file(bmain, filepath, fileflags, &blend_file_write_params, nullptr)) {
+        printf("Saved session recovery to \"%s\"\n", filepath);
       }
-      else {
-        const int fileflags = G.fileflags & ~G_FILE_COMPRESS;
-        BlendFileWriteParams blend_file_write_params{};
-        BLO_write_file(bmain, filepath, fileflags, &blend_file_write_params, nullptr);
-      }
-      printf("Saved session recovery to \"%s\"\n", filepath);
     }
 
     WM_jobs_kill_all(wm);