Keep settings history timestamps on 29 February

dumpsys prints the settings change history without a year, so
_resolve_timestamp() parsed the value with strptime("%m-%d ...") and only
then replaced the year. strptime() parses a value without a year in 1900,
which has no 29 February, so every change made on a leap day raised
ValueError and lost its timestamp, dropping it from the timeline and from
the alert of a dangerous setting.

Parse the value together with a year instead, starting from the year the
section was dumped and going back until the date exists and is not later
than the dump. Eight years always reach a leap year.

This also removes the DeprecationWarning Python 3.13 raises for parsing a
day of month without a year (python/cpython#70647).

src/mvt/android/artifacts/settings.py

@@ -255,19 +255,24 @@ class Settings(AndroidArtifact):
         dumpsys prints the change history without a year, so it is resolved
         against the time the section was dumped: the most recent matching date
         at or before that time.
+
+        The year is parsed together with the value, because strptime() would
+        otherwise parse it in 1900, which has no 29 February. Going back eight
+        years always reaches a leap year.
         """
         if section_end is None:
             return None
 
-        try:
+        for year in range(section_end.year, section_end.year - 8, -1):
-            partial = datetime.strptime(value, "%m-%d %H:%M:%S.%f")
+            try:
-            timestamp = partial.replace(year=section_end.year)
+                timestamp = datetime.strptime(f"{year}-{value}", "%Y-%m-%d %H:%M:%S.%f")
-            if timestamp > section_end:
+            except ValueError:
-                timestamp = partial.replace(year=section_end.year - 1)
+                continue
-        except ValueError:
-            return None
 
-        return convert_datetime_to_iso(timestamp)
+            if timestamp <= section_end:
+                return convert_datetime_to_iso(timestamp)
+
+        return None
 
     def _parse_history(
         self, line: str, section_end: Optional[datetime]

tests/android/test_artifact_settings.py

@@ -3,6 +3,8 @@
 # Use of this software is governed by the MVT License 1.1 that can be found at
 #   https://license.mvt.re/1.1/
 
+from typing import Optional
+
 from mvt.android.artifacts.settings import Settings
 
 from ..utils import get_artifact
@@ -21,6 +23,21 @@ def find(settings: Settings, name: str) -> list:
     return [result for result in settings.results if result["name"] == name]
 
 
+def resolve_history_time(time: str, section_end: str) -> Optional[str]:
+    settings = Settings()
+    settings.parse(
+        "SECURE SETTINGS (user 0)\n"
+        "_id:240 name:accessibility_enabled pkg:android value:1\n"
+        "\tHistory (accessibility_enabled)\n"
+        f"\t\ttime:{time} mode:update oldValue:0 newValue:1 "
+        "package:com.example.helper\n"
+        "\n"
+        "--------- 0.019s was the duration of dumpsys settings, "
+        f"ending at: {section_end}\n"
+    )
+    return settings.results[0]["history"][0]["timestamp"]
+
+
 class TestSettingsArtifact:
     def test_parsing(self):
         settings = parse_bugreport_settings()
@@ -159,6 +176,24 @@ class TestSettingsArtifact:
             }
         ]
 
+    def test_leap_day_history_keeps_its_timestamp(self):
+        assert (
+            resolve_history_time("02-29 22:41:07.980", "2024-03-05 23:14:28")
+            == "2024-02-29 22:41:07.980000"
+        )
+
+    def test_leap_day_history_resolved_to_the_last_leap_year(self):
+        # The most recent 29 February at or before the dump can be several
+        # years back when the dump was taken in a year without one.
+        assert (
+            resolve_history_time("02-29 22:41:07.980", "2025-03-01 10:00:00")
+            == "2024-02-29 22:41:07.980000"
+        )
+        assert (
+            resolve_history_time("02-29 22:41:07.980", "2024-01-10 10:00:00")
+            == "2020-02-29 22:41:07.980000"
+        )
+
     def test_dangerous_setting_is_detected_with_the_changing_package(self):
         settings = parse_bugreport_settings()
         settings.check_indicators()