From 1da48061e3adac40df38e851196ae1fc75aa2367 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bruno=20Perdig=C3=A3o?= <bruno@brunopo.com>
Date: Sat, 5 Sep 2026 23:53:59 -0300
Subject: [PATCH] snap: fix stale cut geometry after file reload

---
 .../bonsai/bim/module/drawing/handler.py      |  3 +++
 src/bonsai/bonsai/tool/raycast.py             | 25 +++++++++++++++----
 2 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/src/bonsai/bonsai/bim/module/drawing/handler.py b/src/bonsai/bonsai/bim/module/drawing/handler.py
index aac48b9479..49bdfac23b 100644
--- a/src/bonsai/bonsai/bim/module/drawing/handler.py
+++ b/src/bonsai/bonsai/bim/module/drawing/handler.py
@@ -31,6 +31,9 @@ def load_post(*args):
     else:
         decoration.DecorationsHandler.uninstall()
 
+    # CutDecorator is drawing-view-only state and must not survive a new file.
+    decoration.CutDecorator.uninstall()
+
 
 @persistent
 def depsgraph_update_pre_handler(scene):
diff --git a/src/bonsai/bonsai/tool/raycast.py b/src/bonsai/bonsai/tool/raycast.py
index bf55f37c7b..892f9688ae 100644
--- a/src/bonsai/bonsai/tool/raycast.py
+++ b/src/bonsai/bonsai/tool/raycast.py
@@ -39,13 +39,15 @@ from mathutils import Matrix, Vector
 
 import bonsai.core.tool
 import bonsai.tool as tool
+from bonsai.bim.decorator_cache import get_decorator_cache_token
 from bonsai.bim.module.drawing.data import DecoratorData
 from bonsai.bim.module.drawing.decoration import CutDecorator
 
-_wireframe_batch_cache: dict[int, dict[str, tuple[GPUBatch, int, list]]] = {}
+_wireframe_batch_cache: dict[tuple[int, int], dict[str, tuple[GPUBatch, int, list]]] = {}
 _wireframe_vert_fmt: GPUVertFormat | None = None
-_triangle_batch_cache: dict[int, tuple[GPUBatch, int]] = {}
+_triangle_batch_cache: dict[tuple[int, int], tuple[GPUBatch, int]] = {}
 _triangle_vert_fmt: GPUVertFormat | None = None
+_last_decorator_cache_token: int | None = None
 _encoding_shader: gpu.types.GPUShader | None = None
 _offscreen: GPUOffScreen | None = None
 _obj_list: list[[bpy.types.Object, bool]] = []
@@ -101,6 +103,16 @@ def _create_vert_format() -> GPUVertFormat:
     return fmt
 
 
+def _discard_stale_batches_if_token_changed() -> None:
+    """Clear GPU batches when the decorator cache token is bumped on file load, undo, redo, or depsgraph changes."""
+    global _last_decorator_cache_token
+    token = get_decorator_cache_token()
+    if token != _last_decorator_cache_token:
+        _triangle_batch_cache.clear()
+        _wireframe_batch_cache.clear()
+        _last_decorator_cache_token = token
+
+
 def _find_closest_wireframe_pixel(buffer_data, cx, cy):
     """Scan *buffer_data* (list of rows) for the closest non-zero pixel
     to (cx, cy). Used for points a lines detection.  Returns ``(encoded_value, dx, dy)`` or None."""
@@ -203,7 +215,8 @@ def _ensure_triangle_batches(obj: bpy.types.Object) -> tuple[GPUBatch | None, bo
     if _triangle_vert_fmt is None:
         _triangle_vert_fmt = _create_vert_format()
 
-    cache_key = id(obj)
+    _discard_stale_batches_if_token_changed()
+    cache_key = (obj.session_uid, get_decorator_cache_token())
     if cache_key in _triangle_batch_cache:
         return _triangle_batch_cache[cache_key]
 
@@ -355,7 +368,8 @@ def _ensure_wireframe_batches(obj: bpy.types.Object) -> dict[str, tuple[GPUBatch
     if _wireframe_vert_fmt is None:
         _wireframe_vert_fmt = _create_vert_format()
 
-    cache_key = id(obj)
+    _discard_stale_batches_if_token_changed()
+    cache_key = (obj.session_uid, get_decorator_cache_token())
 
     # Cache hit
     if cache_key in _wireframe_batch_cache:
@@ -1199,7 +1213,7 @@ class Raycast(bonsai.core.tool.Raycast):
 
     @classmethod
     def clear_cache(cls):
-        global _wireframe_batch_cache, _wireframe_vert_fmt, _triangle_batch_cache, _triangle_vert_fmt, _encoding_shader, _offscreen, _obj_list
+        global _wireframe_batch_cache, _wireframe_vert_fmt, _triangle_batch_cache, _triangle_vert_fmt, _encoding_shader, _offscreen, _obj_list, _last_decorator_cache_token
         _wireframe_batch_cache = {}
         _wireframe_vert_fmt = None
         _triangle_batch_cache = {}
@@ -1207,6 +1221,7 @@ class Raycast(bonsai.core.tool.Raycast):
         _encoding_shader = None
         _offscreen = None
         _obj_list = []
+        _last_decorator_cache_token = None
 
     @classmethod
     def ray_cast_by_proximity(