Cleanup: comments, replace 'undoes' with 'undo-steps'

source/blender/blenkernel/intern/brush.c

@@ -375,7 +375,7 @@ static int brush_undo_preserve_cb(LibraryIDLinkCallbackData *cb_data)
 
 static void brush_undo_preserve(BlendLibReader *reader, ID *id_new, ID *id_old)
 {
-  /* Whole Brush is preserved across undoes. */
+  /* Whole Brush is preserved across undo-steps. */
   BKE_lib_id_swap(NULL, id_new, id_old);
 
   /* `id_new` now has content from `id_old`, we need to ensure those old ID pointers are valid.

source/blender/blenkernel/intern/paint.c

@@ -127,7 +127,7 @@ static void palette_blend_read_data(BlendDataReader *reader, ID *id)
 
 static void palette_undo_preserve(BlendLibReader *UNUSED(reader), ID *id_new, ID *id_old)
 {
-  /* Whole Palette is preserved across undoes, and it has no extra pointer, simple. */
+  /* Whole Palette is preserved across undo-steps, and it has no extra pointer, simple. */
   /* Note: We do not care about potential internal references to self here, Palette has none. */
   /* Note: We do not swap IDProperties, as dealing with potential ID pointers in those would be
    *       fairly delicate. */

source/blender/blenkernel/intern/scene.c

@@ -475,7 +475,7 @@ static void scene_foreach_rigidbodyworldSceneLooper(struct RigidBodyWorld *UNUSE
 
 /**
  * This code is shared by both the regular `foreach_id` looper, and the code trying to restore or
- * preserve ID pointers like brushes across undoes.
+ * preserve ID pointers like brushes across undo-steps.
  */
 typedef enum eSceneForeachUndoPreserveProcess {
   /* Undo when preserving tool-settings from old scene, we also want to try to preserve that ID

source/blender/blenkernel/intern/undo_system.c

@@ -287,7 +287,7 @@ void BKE_undosys_stack_clear(UndoStack *ustack)
 
 void BKE_undosys_stack_clear_active(UndoStack *ustack)
 {
-  /* Remove active and all following undoes. */
+  /* Remove active and all following undo-steps. */
   UndoStep *us = ustack->step_active;
 
   if (us) {
@@ -517,7 +517,7 @@ UndoPushReturn BKE_undosys_step_push_with_type(UndoStack *ustack,
     retval |= UNDO_PUSH_RET_OVERRIDE_CHANGED;
   }
 
-  /* Remove all undoes after (also when 'ustack->step_active == NULL'). */
+  /* Remove all undo-steps after (also when 'ustack->step_active == NULL'). */
   while (ustack->steps.last != ustack->step_active) {
     UndoStep *us_iter = ustack->steps.last;
     undosys_step_free_and_unlink(ustack, us_iter);

source/blender/editors/undo/memfile_undo.c

@@ -314,8 +314,8 @@ struct MemFile *ED_undosys_stack_memfile_get_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".
  *
- * Since non-memfile undoes cannot automatically set this flag in the previous step as done with
- * memfile ones, this has to be called manually by relevant undo code.
+ * Since non-memfile undo-steps cannot automatically set this flag in the previous step as done
+ * with memfile ones, this has to be called manually by relevant undo code.
  *
  * \note Only current known case for this is undoing a switch from Object to Sculpt mode (see
  * T82388).

source/blender/editors/util/ed_util.c

@@ -183,7 +183,7 @@ void ED_editors_exit(Main *bmain, bool do_undo_system)
     return;
   }
 
-  /* Frees all edit-mode undoes. */
+  /* Frees all edit-mode undo-steps. */
   if (do_undo_system && G_MAIN->wm.first) {
     wmWindowManager *wm = G_MAIN->wm.first;
     /* normally we don't check for NULL undo stack,