Restrict is_changed canonicalization

This commit is contained in:
xmarre 2026-03-15 16:44:25 +01:00
parent f1d91a4c8c
commit 4c5f82971e
2 changed files with 42 additions and 5 deletions

View File

@ -246,7 +246,10 @@ def _signature_to_hashable_impl(obj, depth=0, max_depth=_MAX_SIGNATURE_DEPTH, ac
def _signature_to_hashable(obj, max_nodes=_MAX_SIGNATURE_CONTAINER_VISITS):
"""Build the final cache-signature representation in one fail-closed pass."""
result = _signature_to_hashable_impl(obj, budget={"remaining": max_nodes})
try:
result = _signature_to_hashable_impl(obj, budget={"remaining": max_nodes})
except RuntimeError:
return Unhashable()
if result is _FAILED_SIGNATURE:
return Unhashable()
return result[0]
@ -320,10 +323,20 @@ def to_hashable(obj, max_nodes=_MAX_SIGNATURE_CONTAINER_VISITS):
items = snapshots.pop(current_id, None)
if items is None:
items = list(current.items())
memo[current_id] = (
"dict",
tuple((resolve_value(k), resolve_value(v)) for k, v in items),
)
ordered_items = [
(_sanitized_sort_key(k, memo=sort_memo), resolve_value(k), resolve_value(v))
for k, v in items
]
ordered_items.sort(key=lambda item: item[0])
for index in range(1, len(ordered_items)):
if ordered_items[index - 1][0] == ordered_items[index][0]:
memo[current_id] = Unhashable()
break
else:
memo[current_id] = (
"dict",
tuple((key, value) for _, key, value in ordered_items),
)
elif current_type is list:
items = snapshots.pop(current_id, None)
if items is None:

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@ -205,6 +205,17 @@ def test_to_hashable_handles_shared_builtin_substructures(caching_module):
assert hashable[1][0][0] == "list"
def test_to_hashable_canonicalizes_dict_insertion_order(caching_module):
"""Dicts with the same content should hash identically regardless of insertion order."""
caching, _ = caching_module
first = {"b": 2, "a": 1}
second = {"a": 1, "b": 2}
assert caching.to_hashable(first) == ("dict", (("a", 1), ("b", 2)))
assert caching.to_hashable(first) == caching.to_hashable(second)
@pytest.mark.parametrize(
"container_factory",
[
@ -227,6 +238,19 @@ def test_to_hashable_fails_closed_on_runtimeerror(caching_module, monkeypatch, c
assert isinstance(hashable, caching.Unhashable)
def test_to_hashable_fails_closed_for_ambiguous_dict_ordering(caching_module):
"""Ambiguous dict key ordering should fail closed instead of using insertion order."""
caching, _ = caching_module
ambiguous = {
_OpaqueValue(): 1,
_OpaqueValue(): 2,
}
hashable = caching.to_hashable(ambiguous)
assert isinstance(hashable, caching.Unhashable)
def test_signature_to_hashable_fails_closed_for_ambiguous_dict_ordering(caching_module):
"""Ambiguous dict sort ties should fail closed instead of depending on input order."""
caching, _ = caching_module