From 105d468b0f2de7f12b820ec3f3c645ff2b3dd950 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 20 Nov 2023 21:11:15 +0530
Subject: [PATCH] Fix #2043998 [Default Published date on Basic metadata page
 is Dec 0100](https://bugs.launchpad.net/calibre/+bug/2043998)

---
 src/calibre/gui2/__init__.py | 7 ++++---
 src/calibre/utils/date.py    | 5 ++++-
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index ab79ff1a86..86d52eee3d 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -11,7 +11,7 @@ import threading
 from contextlib import contextmanager, suppress
 from functools import lru_cache
 from qt.core import (
-    QApplication, QBuffer, QByteArray, QColor, QDesktopServices, QDialog,
+    QApplication, QBuffer, QByteArray, QColor, QDateTime, QDesktopServices, QDialog,
     QDialogButtonBox, QEvent, QFile, QFileDialog, QFileIconProvider, QFileInfo, QFont,
     QFontDatabase, QFontInfo, QFontMetrics, QGuiApplication, QIcon, QImageReader,
     QImageWriter, QIODevice, QLocale, QNetworkProxyFactory, QObject, QPalette,
@@ -37,7 +37,7 @@ from calibre.gui2.qt_file_dialogs import FileDialog
 from calibre.ptempfile import base_dir
 from calibre.utils.config import Config, ConfigProxy, JSONConfig, dynamic
 from calibre.utils.config_base import tweaks
-from calibre.utils.date import UNDEFINED_DATE, qt_from_dt
+from calibre.utils.date import UNDEFINED_DATE
 from calibre.utils.file_type_icons import EXT_MAP
 from calibre.utils.img import set_image_allocation_limit
 from calibre.utils.localization import get_lang
@@ -446,7 +446,8 @@ create_defs()
 del create_defs
 # }}}
 
-UNDEFINED_QDATETIME = qt_from_dt(UNDEFINED_DATE, as_utc=True)
+UNDEFINED_QDATETIME = QDateTime(
+    UNDEFINED_DATE.year, UNDEFINED_DATE.month, UNDEFINED_DATE.day, UNDEFINED_DATE.hour, UNDEFINED_DATE.minute, UNDEFINED_DATE.second)
 QT_HIDDEN_CLEAR_ACTION = '_q_qlineeditclearaction'
 ALL_COLUMNS = ['title', 'ondevice', 'authors', 'size', 'timestamp', 'rating', 'publisher',
         'tags', 'series', 'pubdate']
diff --git a/src/calibre/utils/date.py b/src/calibre/utils/date.py
index f77cd4e677..f1c26b1015 100644
--- a/src/calibre/utils/date.py
+++ b/src/calibre/utils/date.py
@@ -158,7 +158,7 @@ def safeyear(x):
 def qt_to_dt(qdate_or_qdatetime, as_utc=True):
     from qt.core import Qt, QDateTime
     o = qdate_or_qdatetime
-    if o is None:
+    if o is None or is_date_undefined(qdate_or_qdatetime):
         return UNDEFINED_DATE
     if hasattr(o, 'toUTC'): # QDateTime
         def c(o: QDateTime, tz=utc_tz):
@@ -189,6 +189,9 @@ def qt_to_dt(qdate_or_qdatetime, as_utc=True):
 
 def qt_from_dt(d: datetime, as_utc=False, assume_utc=False):
     from qt.core import QDate, QDateTime, QTime, QTimeZone
+    if is_date_undefined(d):
+        from calibre.gui2 import UNDEFINED_QDATETIME
+        return UNDEFINED_QDATETIME
     if d.tzinfo is None:
         d = d.replace(tzinfo=utc_tz if assume_utc else local_tz)
     if as_utc: