From e13da8104c1314d467272ab1a1e46b84d1180002 Mon Sep 17 00:00:00 2001
From: xmarre <mmquant1@gmail.com>
Date: Wed, 18 Mar 2026 12:26:30 +0100
Subject: [PATCH] Fix shallow is_changed handling

---
 comfy_execution/caching.py      | 18 ++++++++++--------
 tests/execution/test_caching.py | 28 ++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+), 8 deletions(-)

diff --git a/comfy_execution/caching.py b/comfy_execution/caching.py
index fecf54d1e..398036eb8 100644
--- a/comfy_execution/caching.py
+++ b/comfy_execution/caching.py
@@ -68,20 +68,22 @@ _FAILED_SIGNATURE = object()
 
 
 def _shallow_is_changed_signature(value):
-    """Sanitize execution-time `is_changed` values with a small fail-closed budget."""
+    """Reduce execution-time `is_changed` values without deep traversal."""
     value_type = type(value)
     if value_type in _PRIMITIVE_SIGNATURE_TYPES:
         return value
 
-    canonical = to_hashable(value, max_nodes=64)
-    if type(canonical) is Unhashable:
-        return canonical
-
     if value_type is list or value_type is tuple:
-        container_tag = "is_changed_list" if value_type is list else "is_changed_tuple"
-        return (container_tag, canonical[1])
+        try:
+            items = tuple(value)
+        except RuntimeError:
+            return Unhashable()
+        if all(type(item) in _PRIMITIVE_SIGNATURE_TYPES for item in items):
+            container_tag = "is_changed_list" if value_type is list else "is_changed_tuple"
+            return (container_tag, items)
+        return Unhashable()
 
-    return canonical
+    return Unhashable()
 
 
 def _primitive_signature_sort_key(obj):
diff --git a/tests/execution/test_caching.py b/tests/execution/test_caching.py
index 569bf5bd8..db6d95063 100644
--- a/tests/execution/test_caching.py
+++ b/tests/execution/test_caching.py
@@ -25,6 +25,34 @@ class _StubNode:
         return {"required": {}}
 
 
+def test_shallow_is_changed_signature_keeps_primitive_only_list_shallow():
+    assert caching._shallow_is_changed_signature([1, "two", None, True]) == (
+        "is_changed_list",
+        (1, "two", None, True),
+    )
+
+
+def test_shallow_is_changed_signature_keeps_primitive_only_tuple_shallow():
+    assert caching._shallow_is_changed_signature((1, "two", None, True)) == (
+        "is_changed_tuple",
+        (1, "two", None, True),
+    )
+
+
+def test_shallow_is_changed_signature_fails_closed_for_nested_container(monkeypatch):
+    monkeypatch.setattr(
+        caching,
+        "to_hashable",
+        lambda *_args, **_kwargs: (_ for _ in ()).throw(
+            AssertionError("is_changed signature must not deep-canonicalize")
+        ),
+    )
+
+    signature = caching._shallow_is_changed_signature([1, [2, 3]])
+
+    assert isinstance(signature, caching.Unhashable)
+
+
 def test_get_immediate_node_signature_canonicalizes_non_link_inputs(monkeypatch):
     live_value = [1, {"nested": [2, 3]}]
     dynprompt = _StubDynPrompt(