Fix handling of day-of-week in QDateTimeParser and QDateTimeEdit

QDTP's absoluteMax(), setDigit() and getDigit() simply treated
day-of-week as synonym for day-of-month.
Consequently, QDTE::stepBy() did the same.

This meant that wrapping happened at the month boundary, so would jump
within the week if it wrapped around, otherwise the up/down arrow
would "jam" at a particular day of the week when further steps would
leave the month. Instead, when wrapping, wrap round the week while
still moving the day-of-month to match, jumping back or forward a week
to stay within the month on hitting a month boundary; otherwise, stop
backwards stepping on hitting the locale-specific day of the week, or
forward stepping when the step would be to or past this first day.
Fixed various bugs found in the course of testing this.

[ChangeLog][QtWidgets][QDateTimeEdit] Corrected handling of weekdays.
Previously, changes to the week-day were simply changes to the day of
the month. Weekday fields are now handled as such: changes to them do
change the day of the month, but a change that would step past the end
(or start) of the month is adjusted to the relevant day of the nearest
week within the month. When wrapping is disabled, the locale-specific
first and last days of the week are the bounds. Formats which specify
day of week but not day of month will now preserve day of week when
changing month or year, selecting the nearest day of month that
matches.

Change-Id: I7868b000fea7a4bc17a1b5687c44bcd56d42ae90
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 18 insertions, 12 deletions

diff --git a/tests/auto/widgets/widgets/qdatetimeedit/tst_qdatetimeedit.cpp b/tests/auto/widgets/widgets/qdatetimeedit/tst_qdatetimeedit.cpp
index 5f003928c0..ad16fcc79f 100644
--- a/tests/auto/widgets/widgets/qdatetimeedit/tst_qdatetimeedit.cpp
+++ b/tests/auto/widgets/widgets/qdatetimeedit/tst_qdatetimeedit.cpp
@@ -4009,20 +4009,23 @@ void tst_QDateTimeEdit::dateEditCorrectSectionSize_data()
     KeyPairList shortAndLongNameIssueKeypresses;
     shortAndLongNameIssueKeypresses << key(Qt::Key_Tab) << key(Qt::Key_3) << key(Qt::Key_1) << key(Qt::Key_Up);
 
+    // When day-of-week is specified, rather than day-of-month, changing month
+    // cares more about preserving day-of-week than day-of-month, so Jan/31 ->
+    // Feb picks 28th even in a leap year, as that's exactly four weeks later.
     QTest::newRow("no fixday, leap, yy/M/dddd")
         << ozzy << y2kStart << QString::fromLatin1("yy/M/dddd")
         << threeDigitDayIssueKeypresses_DayName
-        << QDate(2000, 2, 29) << QString::fromLatin1("00/2/Tuesday");
+        << QDate(2000, 2, 28) << QString::fromLatin1("00/2/Monday");
 
     QTest::newRow("no fixday, leap, yy/M/ddd")
         << ozzy << y2kStart << QString::fromLatin1("yy/M/ddd")
         << threeDigitDayIssueKeypresses_DayName
-        << QDate(2000, 2, 29) << QString::fromLatin1("00/2/Tue");
+        << QDate(2000, 2, 28) << QString::fromLatin1("00/2/Mon");
 
     QTest::newRow("no fixday, leap, yy/MM/dddd")
         << ozzy << y2kStart << QString::fromLatin1("yy/MM/dddd")
         << threeDigitDayIssueKeypresses_DayName
-        << QDate(2000, 2, 29) << QString::fromLatin1("00/02/Tuesday");
+        << QDate(2000, 2, 28) << QString::fromLatin1("00/02/Monday");
 
     QTest::newRow("fixday, leap, yy/MM/dd")
         << ozzy << y2kStart << QString::fromLatin1("yy/MM/dd")
@@ -4072,12 +4075,12 @@ void tst_QDateTimeEdit::dateEditCorrectSectionSize_data()
     QTest::newRow("no fixday, leap, yyyy/M/dddd")
         << ozzy << y2kStart << QString::fromLatin1("yyyy/M/dddd")
         << threeDigitDayIssueKeypresses_DayName
-        << QDate(2000, 2, 29) << QString::fromLatin1("2000/2/Tuesday");
+        << QDate(2000, 2, 28) << QString::fromLatin1("2000/2/Monday");
 
     QTest::newRow("no fixday, leap, yyyy/MM/dddd")
         << ozzy << y2kStart << QString::fromLatin1("yyyy/MM/dddd")
         << threeDigitDayIssueKeypresses_DayName
-        << QDate(2000, 2, 29) << QString::fromLatin1("2000/02/Tuesday");
+        << QDate(2000, 2, 28) << QString::fromLatin1("2000/02/Monday");
 
     QTest::newRow("fixday, leap, yyyy/dd/MM")
         << ozzy << y2kStart << QString::fromLatin1("yyyy/dd/MM")
@@ -4112,12 +4115,12 @@ void tst_QDateTimeEdit::dateEditCorrectSectionSize_data()
     QTest::newRow("fixday, leap, yyyy/dddd/M")
         << ozzy << y2kStart << QString::fromLatin1("yyyy/dddd/M")
         << threeDigitDayIssueKeypresses_DayName_YearDayMonth
-        << QDate(2000, 2, 29) << QString::fromLatin1("2000/Tuesday/2");
+        << QDate(2000, 2, 28) << QString::fromLatin1("2000/Monday/2");
 
     QTest::newRow("fixday, leap, yyyy/dddd/MM")
         << ozzy << y2kStart << QString::fromLatin1("yyyy/dddd/MM")
         << threeDigitDayIssueKeypresses_DayName_YearDayMonth
-        << QDate(2000, 2, 29) << QString::fromLatin1("2000/Tuesday/02");
+        << QDate(2000, 2, 28) << QString::fromLatin1("2000/Monday/02");
 
     QTest::newRow("fixday, leap, d/M/yyyy")
         << ozzy << y2kStart << QString::fromLatin1("d/M/yyyy")
@@ -4137,7 +4140,7 @@ void tst_QDateTimeEdit::dateEditCorrectSectionSize_data()
     QTest::newRow("fixday, leap, dddd/MM/yyyy")
         << ozzy << y2kStart << QString::fromLatin1("dddd/MM/yyyy")
         << threeDigitDayIssueKeypresses_DayName_DayMonthYear
-        << QDate(2000, 2, 29) << QString::fromLatin1("Tuesday/02/2000");
+        << QDate(2000, 2, 28) << QString::fromLatin1("Monday/02/2000");
 
     QTest::newRow("fixday, leap, d/yy/M")
         << ozzy << y2kStart << QString::fromLatin1("d/yy/M")
@@ -4172,12 +4175,12 @@ void tst_QDateTimeEdit::dateEditCorrectSectionSize_data()
     QTest::newRow("fixday, leap, dddd/yy/M")
         << ozzy << y2kStart << QString::fromLatin1("dddd/yy/M")
         << threeDigitDayIssueKeypresses_DayName_DayYearMonth
-        << QDate(2000, 2, 29) << QString::fromLatin1("Tuesday/00/2");
+        << QDate(2000, 2, 28) << QString::fromLatin1("Monday/00/2");
 
     QTest::newRow("fixday, leap, dddd/yy/MM")
         << ozzy << y2kStart << QString::fromLatin1("dddd/yy/MM")
         << threeDigitDayIssueKeypresses_DayName_DayYearMonth
-        << QDate(2000, 2, 29) << QString::fromLatin1("Tuesday/00/02");
+        << QDate(2000, 2, 28) << QString::fromLatin1("Monday/00/02");
 
     QTest::newRow("fixday, leap, M/d/yy")
         << ozzy << y2kStart << QString::fromLatin1("M/d/yy")
@@ -4197,7 +4200,7 @@ void tst_QDateTimeEdit::dateEditCorrectSectionSize_data()
     QTest::newRow("fixday, leap, M/dddd/yyyy")
         << ozzy << y2kStart << QString::fromLatin1("M/dddd/yyyy")
         << threeDigitDayIssueKeypresses_DayName_MonthDayYear
-        << QDate(2000, 2, 29) << QString::fromLatin1("2/Tuesday/2000");
+        << QDate(2000, 2, 28) << QString::fromLatin1("2/Monday/2000");
 
     QTest::newRow("fixday, leap, MM/dd/yyyy")
         << ozzy << y2kStart << QString::fromLatin1("MM/dd/yyyy")
@@ -4207,7 +4210,7 @@ void tst_QDateTimeEdit::dateEditCorrectSectionSize_data()
     QTest::newRow("fixday, leap, MM/dddd/yyyy")
         << ozzy << y2kStart << QString::fromLatin1("MM/dddd/yyyy")
         << threeDigitDayIssueKeypresses_DayName_MonthDayYear
-        << QDate(2000, 2, 29) << QString::fromLatin1("02/Tuesday/2000");
+        << QDate(2000, 2, 28) << QString::fromLatin1("02/Monday/2000");
 
     QTest::newRow("fixday, leap, M/yyyy/dd")
         << ozzy << y2kStart << QString::fromLatin1("M/yyyy/dd")
@@ -4275,6 +4278,9 @@ void tst_QDateTimeEdit::dateEditCorrectSectionSize()
     edit.setDisplayFormat(displayFormat);
     edit.show();
     edit.setFocus();
+    // Day-of-week tests rely on advance through week advancing the
+    // day-of-month, so not stopping at the locale's first day of the week:
+    edit.setWrapping(true);
     // For some reason, we need to set the selected section for the dd/MM/yyyy tests,
     // otherwise the 3 is inserted at the front of 01/01/2000 (301/01/2000), instead of the
     // selected text being replaced. This is not an issue for the yyyy/MM/dd format though...