Resolves: tdf#100452 class Date full (BCE,CE) proleptic Gregorian calendar

... implementing signed years with year 0 gap.
Date(31,12,-1) last day BCE
Date(1,1,1) first day CE

New class Date member functions:
* AddYears(sal_Int16) to be used instead of
aDate.SetYear(aDate.GetYear()+sal_Int16) to handle year 0 gap.
* convenience GetNextYear() to be used insted of GetYear()+1
* convenience GetPrevYear() to be used insted of GetYear()-1
* AddMonths(sal_Int32)
* operator=(const css::util::Date&)

New class DateTime member functions:
* operator=(const css::util::DateTime&)

Made some conversion ctors explicit, specifically Date(sal_Int32)

Adapted hopefully all places that used a sal_uInt16 year to use
sal_Int16 where appropriate.

Eliminated some quirks in date handling found on the fly.

Added era handling to i18npool icu calendar setting interface, which
missing was responsible for 0001-01-01 entered in Calc being set as
-0001-01-01, hence subtracting one day resulted in -0002-12-31.

Change-Id: I77b39fba9599ebd5067d7864f6c9ebe01f6f578f
Reviewed-on: https://gerrit.libreoffice.org/27049
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Jenkins <ci@libreoffice.org>

1 files changed, 76 insertions, 0 deletions

diff --git a/tools/qa/cppunit/test_date.cxx b/tools/qa/cppunit/test_date.cxx
new file mode 100644
index 000000000000..0ee30089b7b5
--- /dev/null
+++ b/tools/qa/cppunit/test_date.cxx
@@ -0,0 +1,76 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#include <cppunit/TestFixture.h>
+#include <cppunit/extensions/HelperMacros.h>
+
+#include <tools/date.hxx>
+
+namespace tools
+{
+
+class DateTest : public CppUnit::TestFixture
+{
+public:
+    void testDate();
+
+    CPPUNIT_TEST_SUITE(DateTest);
+    CPPUNIT_TEST(testDate);
+    CPPUNIT_TEST_SUITE_END();
+};
+
+void DateTest::testDate()
+{
+    const Date aCE(1,1,1);          // first day CE
+    const Date aBCE(31,12,-1);      // last day BCE
+    const Date aMin(1,1,-32768);    // minimum date
+    const Date aMax(31,12,32767);   // maximum date
+    Date aDate(Date::EMPTY);
+    const long kMinDays = -11968265;
+    const long kMaxDays =  11967900;
+
+    // Last day BCE to first day CE is 1 day difference.
+    CPPUNIT_ASSERT_EQUAL( static_cast<long>(1), aCE - aBCE);
+    CPPUNIT_ASSERT_EQUAL( static_cast<long>(-1), aBCE - aCE);
+    aDate = aBCE;
+    CPPUNIT_ASSERT_EQUAL( aCE.GetDate(), (aDate += 1).GetDate());
+    aDate = aCE;
+    CPPUNIT_ASSERT_EQUAL( aBCE.GetDate(), (aDate -= 1).GetDate());
+
+    // The entire BCE and CE ranges cover that many days. Day 0 is -0001-12-31
+    CPPUNIT_ASSERT_EQUAL( kMaxDays, aMax - aBCE);
+    CPPUNIT_ASSERT_EQUAL( kMinDays, aMin - aBCE);
+
+    // Truncate at limits, not under-/overflow or wrap.
+    aDate = aMin;
+    CPPUNIT_ASSERT_EQUAL( aMin.GetDate(), (aDate -= 1).GetDate());
+    aDate = aMax;
+    CPPUNIT_ASSERT_EQUAL( aMax.GetDate(), (aDate += 1).GetDate());
+    aDate = aBCE;
+    CPPUNIT_ASSERT_EQUAL( aMin.GetDate(), (aDate += (kMinDays-10)).GetDate());
+    aDate = aBCE;
+    CPPUNIT_ASSERT_EQUAL( aMax.GetDate(), (aDate += (kMaxDays+10)).GetDate());
+
+    // Year -1 is a leap year.
+    aDate = Date(28,2,-1);
+    CPPUNIT_ASSERT_EQUAL( Date(29,2,-1).GetDate(), (aDate += 1).GetDate());
+    aDate = Date(1,3,-1);
+    CPPUNIT_ASSERT_EQUAL( Date(29,2,-1).GetDate(), (aDate -= 1).GetDate());
+    // Year -5 is a leap year.
+    aDate = Date(28,2,-5);
+    CPPUNIT_ASSERT_EQUAL( Date(29,2,-5).GetDate(), (aDate += 1).GetDate());
+    aDate = Date(1,3,-5);
+    CPPUNIT_ASSERT_EQUAL( Date(29,2,-5).GetDate(), (aDate -= 1).GetDate());
+}
+
+CPPUNIT_TEST_SUITE_REGISTRATION(DateTest);
+
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */