fix(transfer): tolerate mtime precision drift in history gate

app/application/history/retry.py

@@ -2,6 +2,7 @@
 
 from __future__ import annotations
 
+import math
 from typing import Any, Dict, Optional
 
 from app.application.configuration import TransferRetryConfig, get_transfer_retry_config
@@ -17,6 +18,8 @@ from app.runtime.log import logger
 MIN_FAILED_RETRIES = 1
 MAX_FAILED_RETRIES = 10
 FAILED_RETRY_TTL = 24 * 3600
+# 不同存储后端对秒级修改时间的浮点和序列化误差可能达到毫秒；更大的变化仍视为新版本。
+MODIFY_TIME_TOLERANCE = 1e-3
 
 # 缓存值会同时保存文件指纹，使同一路径的新版本获得独立重试预算。
 _failed_retry_counts = TTLCache(
@@ -140,14 +143,23 @@ def _is_file_version_changed(
         recorded_fingerprint: Dict[str, Any],
         current_fingerprint: Dict[str, Any],
 ) -> bool:
-    """判断两个可比文件指纹是否指向不同版本。"""
+    """判断两个可比文件指纹是否指向不同版本，忽略修改时间的毫秒级误差。"""
     for field in ("fileid", "modify_time", "size"):
         recorded_value = recorded_fingerprint.get(field)
         current_value = current_fingerprint.get(field)
         if (
                 recorded_value is not None
                 and current_value is not None
-                and recorded_value != current_value
+                and (
+                    not math.isclose(
+                        recorded_value,
+                        current_value,
+                        rel_tol=0.0,
+                        abs_tol=MODIFY_TIME_TOLERANCE,
+                    )
+                    if field == "modify_time"
+                    else recorded_value != current_value
+                )
         ):
             return True
     return False

app/chain/transfer/execution.py

@@ -591,7 +591,7 @@ class TransferExecutionOwner(_TransferOwnerBase):
                 if task.mediainfo.tmdb_id:
                     error_message = "TMDB 信息未匹配到媒体分类，无法按媒体类别整理"
                 else:
-                    error_message = "未识别到 TMDB 辅助信息，无法按媒体类别整理"
+                    error_message = "媒体识别结果未匹配到媒体分类，无法按媒体类别整理"
                 logger.error(f"{task.fileitem.name} {error_message}")
                 if task.preview:
                     return False, error_message

tests/test_transfer_history_gate.py

@@ -79,6 +79,28 @@ def test_evaluate_history_gate_skips_when_success_size_unchanged():
     assert action == HistoryGateAction.SKIP
 
 
+@pytest.mark.parametrize(
+    "current_modify_time, expected",
+    [
+        (100.0005, HistoryGateAction.SKIP),
+        (100.01, HistoryGateAction.PASS_SIZE_CHANGED),
+    ],
+)
+def test_evaluate_history_gate_uses_tolerance_for_modify_time(
+        current_modify_time, expected,
+):
+    """修改时间仅有毫秒级浮点漂移时应保持原版本，明显变化仍应放行。"""
+    history = make_history(status=True, size=1024, modify_time=100.0)
+
+    action = evaluate_history_gate(
+        history,
+        file_size=1024,
+        file_modify_time=current_modify_time,
+    )
+
+    assert action == expected
+
+
 def test_evaluate_history_gate_skips_when_recorded_size_missing():
     """成功记录缺少大小信息（如蓝光目录）时无法比对，保守跳过。"""
     history = make_history(status=True, has_src_fileitem=False)

tests/test_transfer_tmdb_category.py

@@ -161,7 +161,7 @@ def test_transfer_stops_when_automatic_category_has_no_tmdb_result(monkeypatch)
     state, message = chain._TransferChain__handle_transfer(task)
 
     assert not state
-    assert message == "未识别到 TMDB 辅助信息，无法按媒体类别整理"
+    assert message == "媒体识别结果未匹配到媒体分类，无法按媒体类别整理"
     assert task.mediainfo.media_source == MediaSource.AniList
     assert task.mediainfo.media_id == "1234"
     assert task.plan_checkpoint is not None