Fix for datetime tzinfo conversion

Author: jhonabreul

src/embed_tests/TestConverter.cs

@@ -231,6 +231,36 @@ def GetNextDay(dateTime):
 
                 var expectedDateTime = new DateTime(year, month, day, hour, minute, second);
                 Assert.AreEqual(expectedDateTime, managedDateTime);
+
+                Assert.AreEqual(DateTimeKind.Unspecified, managedDateTime.Kind);
+            }
+        }
+
+        [Test]
+        public void ConvertDateTimeWithExplicitUTCTimeZonePythonToCSharp()
+        {
+            const int year = 2024;
+            const int month = 2;
+            const int day = 27;
+            const int hour = 12;
+            const int minute = 30;
+            const int second = 45;
+
+            using (Py.GIL())
+            {
+                var csDateTime = new DateTime(year, month, day, hour, minute, second, DateTimeKind.Utc);
+                // Converter.ToPython will set the datetime tzinfo to UTC using a custom tzinfo class
+                using var pyDateTime = Converter.ToPython(csDateTime).MoveToPyObject();
+                var dateTimeResult = default(object);
+
+                Assert.DoesNotThrow(() => Converter.ToManaged(pyDateTime, typeof(DateTime), out dateTimeResult, false));
+
+                var managedDateTime = (DateTime)dateTimeResult;
+
+                var expectedDateTime = new DateTime(year, month, day, hour, minute, second);
+                Assert.AreEqual(expectedDateTime, managedDateTime);
+
+                Assert.AreEqual(DateTimeKind.Utc, managedDateTime.Kind);
             }
         }
 

src/runtime/Converter.cs

@@ -1123,13 +1123,31 @@ internal static bool ToPrimitive(BorrowedReference value, Type obType, out objec
                     var minute = Runtime.PyObject_GetAttrString(value, minutePtr);
                     var second = Runtime.PyObject_GetAttrString(value, secondPtr);
                     var microsecond = Runtime.PyObject_GetAttrString(value, microsecondPtr);
+                    var timeKind = DateTimeKind.Unspecified;
+                    var tzinfo = Runtime.PyObject_GetAttrString(value, tzinfoPtr);
+
+                    NewReference hours = default;
+                    NewReference minutes = default;
+                    if (!ReferenceNullOrNone(tzinfo))
+                    {
+                        // We set the datetime kind to UTC if the tzinfo was set to UTC by the ToPthon method
+                        // using it's custom GMT Python tzinfo class
+                        hours = Runtime.PyObject_GetAttrString(tzinfo.Borrow(), hoursPtr);
+                        minutes = Runtime.PyObject_GetAttrString(tzinfo.Borrow(), minutesPtr);
+                        if (!ReferenceNullOrNone(hours) &&
+                            !ReferenceNullOrNone(minutes) &&
+                            Runtime.PyLong_AsLong(hours.Borrow()) == 0 && Runtime.PyLong_AsLong(minutes.Borrow()) == 0)
+                        {
+                            timeKind = DateTimeKind.Utc;
+                        }
+                    }
 
                     var convertedHour = 0L;
                     var convertedMinute = 0L;
                     var convertedSecond = 0L;
                     var milliseconds = 0L;
                     // could be python date type
-                    if (!hour.IsNull() && !hour.IsNone())
+                    if (!ReferenceNullOrNone(hour))
                     {
                         convertedHour = Runtime.PyLong_AsLong(hour.Borrow());
                         convertedMinute = Runtime.PyLong_AsLong(minute.Borrow());
@@ -1143,7 +1161,8 @@ internal static bool ToPrimitive(BorrowedReference value, Type obType, out objec
                         (int)convertedHour,
                         (int)convertedMinute,
                         (int)convertedSecond,
-                        (int)milliseconds);
+                        (int)milliseconds,
+                        timeKind);
 
                     year.Dispose();
                     month.Dispose();
@@ -1153,6 +1172,16 @@ internal static bool ToPrimitive(BorrowedReference value, Type obType, out objec
                     second.Dispose();
                     microsecond.Dispose();
 
+                    if (!tzinfo.IsNull())
+                    {
+                        tzinfo.Dispose();
+                        if (!tzinfo.IsNone())
+                        {
+                            hours.Dispose();
+                            minutes.Dispose();
+                        }
+                    }
+
                     Exceptions.Clear();
                     return true;
                 default:
@@ -1183,6 +1212,11 @@ internal static bool ToPrimitive(BorrowedReference value, Type obType, out objec
             return false;
         }
 
+        private static bool ReferenceNullOrNone(NewReference reference)
+        {
+            return reference.IsNull() || reference.IsNone();
+        }
+
 
         private static void SetConversionError(BorrowedReference value, Type target)
         {