Handle specified time-spec in date-time parsing

When a date-time was parsed from a string, the result was equal (as a
date-time) to the correct value, but had (at least in some cases) the
wrong spec, where it should have had a spec reflecting the zone
specifier parsed.

The time-spec imposed for the benefit of QDateTimeEdit is now moved
from QDateTimeParser to QDateTimeEditPrivate, which takes over
responsibility for imposing it. QDateTimeParser assumes Qt::LocalTime
in member functions (where applicable) and uses the time-spec parsed
from the string when constructing the date-time.

QDateTime::fromString() and QLocale::toDateTime() are updated to
use the full QDateTime returned by QDateTimeParser.

Fixes: QTBUG-83075
Done-With: Edward Welbourne <edward.welbourne@qt.io>
Change-Id: I8b79add2c7fc13a200e1252d48dbfa70b36757bf
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 3 insertions, 4 deletions

diff --git a/src/corelib/time/qdatetime.cpp b/src/corelib/time/qdatetime.cpp
index 9d95f6eb1c..36942bf68e 100644
--- a/src/corelib/time/qdatetime.cpp
+++ b/src/corelib/time/qdatetime.cpp
@@ -5537,13 +5537,12 @@ QT_WARNING_POP
 QDateTime QDateTime::fromString(const QString &string, const QString &format, QCalendar cal)
 {
 #if QT_CONFIG(datetimeparser)
-    QTime time;
-    QDate date;
+    QDateTime datetime;
 
     QDateTimeParser dt(QMetaType::QDateTime, QDateTimeParser::FromString, cal);
     // dt.setDefaultLocale(QLocale::c()); ### Qt 6
-    if (dt.parseFormat(format) && dt.fromString(string, &date, &time))
-        return QDateTime(date, time);
+    if (dt.parseFormat(format) && dt.fromString(string, &datetime))
+        return datetime;
 #else
     Q_UNUSED(string);
     Q_UNUSED(format);