[pp:mtime] fix '_mtime_meta' for invalid values (#8918)

fixes regression introduced in d57dc48dcd
also prevents previous _mtime_meta entries from affecting new files

gallery_dl/postprocessor/mtime.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2019-2022 Mike Fährmann
+# Copyright 2019-2026 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -30,15 +30,14 @@ class MtimePP(PostProcessor):
         job.register_hooks({event: self.run for event in events}, options)
 
     def run(self, pathfmt):
-        mtime = self._get(pathfmt.kwdict)
-        if mtime is None:
-            return
-
-        pathfmt.kwdict["_mtime_meta"] = (
-            dt.to_ts(mtime)
-            if isinstance(mtime, dt.datetime) else
-            text.parse_int(mtime)
-        )
+        if mtime := self._get(pathfmt.kwdict):
+            if isinstance(mtime, dt.datetime):
+                mtime = dt.to_ts(mtime)
+            else:
+                mtime = text.parse_int(mtime)
+        else:
+            mtime = None
+        pathfmt.kwdict["_mtime_meta"] = mtime
 
 
 __postprocessor__ = MtimePP

gallery_dl/version.py

@@ -6,5 +6,5 @@
 # it under the terms of the GNU General Public License version 2 as
 # published by the Free Software Foundation.
 
-__version__ = "1.31.4"
+__version__ = "1.31.5-dev"
 __variant__ = None

test/test_postprocessor.py

@@ -21,7 +21,7 @@ from datetime import datetime
 
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 from gallery_dl import extractor, output, path, util, exception  # noqa E402
-from gallery_dl import postprocessor, config, archive  # noqa E402
+from gallery_dl import postprocessor, config, archive, dt  # noqa E402
 from gallery_dl.postprocessor.common import PostProcessor  # noqa E402
 
 
@@ -931,12 +931,22 @@ class MtimeTest(BasePostprocessorTest):
     def test_mtime_none(self):
         self._create(None, {"date": None})
         self._trigger()
-        self.assertNotIn("_mtime_meta", self.pathfmt.kwdict)
+        self.assertFalse(self.pathfmt.kwdict["_mtime_meta"])
+
+    def test_mtime_none_dt(self):
+        self._create(None, {"date": dt.NONE})
+        self._trigger()
+        self.assertFalse(self.pathfmt.kwdict["_mtime_meta"])
 
     def test_mtime_undefined(self):
         self._create(None, {})
         self._trigger()
-        self.assertNotIn("_mtime_meta", self.pathfmt.kwdict)
+        self.assertFalse(self.pathfmt.kwdict["_mtime_meta"])
+
+    def test_mtime_invalid(self):
+        self._create(None, {"date": "foobar"})
+        self._trigger()
+        self.assertFalse(self.pathfmt.kwdict["_mtime_meta"])
 
     def test_mtime_key(self):
         self._create({"key": "foo"}, {"foo": 315532800})