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, 2 insertions, 2 deletions

diff --git a/include/editeng/flditem.hxx b/include/editeng/flditem.hxx
index 649167a20118..fd01faed6d83 100644
--- a/include/editeng/flditem.hxx
+++ b/include/editeng/flditem.hxx
@@ -106,7 +106,7 @@ enum SvxDateFormat {    SVXDATEFORMAT_APPDEFAULT = 0,   // Set as in App
 
 class EDITENG_DLLPUBLIC SvxDateField : public SvxFieldData
 {
-    sal_uInt32              nFixDate;
+    sal_Int32               nFixDate;
     SvxDateType             eType;
     SvxDateFormat           eFormat;
 
@@ -118,7 +118,7 @@ public:
                                 SvxDateType eType = SVXDATETYPE_VAR,
                                 SvxDateFormat eFormat = SVXDATEFORMAT_STDSMALL );
 
-    sal_uInt32              GetFixDate() const { return nFixDate; }
+    sal_Int32               GetFixDate() const { return nFixDate; }
     void                    SetFixDate( const Date& rDate ) { nFixDate = rDate.GetDate(); }
 
     SvxDateType             GetType() const { return eType; }