Handle trailing cruft consistently in Qt::DateFormat parsing

Previously the ISO time format would tolerate trailing cruft at the
end in various cases even though there might be an offset specifier
after the time, which should *not* be separated from it by anything
(not even the spaces we originally planned to still tolerate).

The RFC date format is forgiving about space, as is suitable for
parsing of RFC-822 headers, but the other formats should match the
handling in QDateTimeParser, which rejects any dangling cruft.

At the same time, since this required a re-write of
fromIsoTimeString() in any case, add support for the ISO format that
gives the hour a fractional part and skips minutes and
seconds. Previously we only had support for fractional minutes (with
no seconds). The hour without even a fractional part is also valid.

Reworked the documentation of Qt::DateFormat as it was wrong in
places, inconsistent in its formatting and incomplete. Adjusted some
tests to match the new behavior. A fraction separator with no
following digits should have been recognized as an error previously
and now is.

[ChangeLog][QtCore][QDateTime] The ISODate and ISODateWithMs formats
now reject trailing cruft (including spaces) at the end of a time
string. They also gain support for parsing hour-only formats,
including the hour-with-fractional-part format.

Task-number: QTBUG-86133
Change-Id: I38ad1479ae033407f7df97ffbeb7c4bcd463d04a
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Paul Wicking <paul.wicking@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/tests/auto/corelib/time/qdatetime/tst_qdatetime.cpp b/tests/auto/corelib/time/qdatetime/tst_qdatetime.cpp
index 855b7273c8..b414458466 100644
--- a/tests/auto/corelib/time/qdatetime/tst_qdatetime.cpp
+++ b/tests/auto/corelib/time/qdatetime/tst_qdatetime.cpp
@@ -2211,8 +2211,7 @@ void tst_QDateTime::fromStringDateFormat_data()
 
     // Test Qt::ISODate format.
     QTest::newRow("trailing space") // QTBUG-80445
-        << QString("2000-01-02 03:04:05.678 ")
-        << Qt::ISODate << QDateTime(QDate(2000, 1, 2), QTime(3, 4, 5, 678));
+        << QString("2000-01-02 03:04:05.678 ") << Qt::ISODate << QDateTime();
 
     // Invalid spaces (but keeping field widths correct):
     QTest::newRow("space before millis")
@@ -2327,8 +2326,8 @@ void tst_QDateTime::fromStringDateFormat_data()
         << Qt::ISODate << QDateTime(QDate(2012, 1, 1), QTime(8, 0, 0, 333), Qt::LocalTime);
     QTest::newRow("ISO .00009 of a second (period)") << QString::fromLatin1("2012-01-01T08:00:00.00009")
         << Qt::ISODate << QDateTime(QDate(2012, 1, 1), QTime(8, 0, 0, 0), Qt::LocalTime);
-    QTest::newRow("ISO no fract specified") << QString::fromLatin1("2012-01-01T08:00:00.")
-        << Qt::ISODate << QDateTime(QDate(2012, 1, 1), QTime(8, 0, 0, 0), Qt::LocalTime);
+    QTest::newRow("ISO no fraction specified")
+        << QString::fromLatin1("2012-01-01T08:00:00.") << Qt::ISODate << QDateTime();
     // Test invalid characters (should ignore invalid characters at end of string).
     QTest::newRow("ISO invalid character at end") << QString::fromLatin1("2012-01-01T08:00:00!")
         << Qt::ISODate << QDateTime();