Added some TODO remarks.

source/blender/editors/animation/anim_draw.c

@@ -522,6 +522,7 @@ static bool find_prev_next_keyframes(struct bContext *C, int *r_nextfra, int *r_
     mask_to_keylist(&ads, masklay, keylist);
   }
 
+  /* TODO(jbakker): Keylists are ordered, no need to do any searching at all. */
   /* find matching keyframe in the right direction */
   do {
     aknext = ED_keylist_find_next(keylist, cfranext);

source/blender/editors/animation/anim_motion_paths.c

@@ -234,6 +234,7 @@ static void motionpath_get_global_framerange(ListBase *targets, int *r_sfra, int
   }
 }
 
+/* TODO(jbakker): Remove complexity, keylists are ordered. */
 static int motionpath_get_prev_keyframe(MPathTarget *mpt,
                                         struct AnimKeylist *keylist,
                                         int current_frame)