tdf#120394: list format string can be empty

We need to distunguish when we have list format string, but it
is empty (no level text will be diplayed) or it does not exist
at all, so we need to fallback to old prefix-suffix syntax.

Change-Id: Ifd4ccd5a676db86c39d2ef48e91d191d92b9b2a0
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/94322
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>

include/editeng/numitem.hxx

@@ -31,6 +31,7 @@
 #include <editeng/editengdllapi.h>
 #include <o3tl/typed_flags_set.hxx>
 #include <memory>
+#include <optional>
 #include <algorithm>
 
 class SvxBrushItem;
@@ -103,7 +104,9 @@ public:
 private:
     OUString            sPrefix;
     OUString            sSuffix;
-    OUString            sListFormat;        // Format string ">%1.%2<" can be used instead of prefix/suffix
+    std::optional<OUString> sListFormat;        // Format string ">%1.%2<" can be used instead of prefix/suffix
+                                                // Right now it is optional value to dostinguish empty list format
+                                                // and not set list format when we need to fallback to prefix/suffix.
 
     SvxAdjust           eNumAdjust;
 
@@ -169,7 +172,8 @@ public:
     void            SetSuffix(const OUString& rSet) { sSuffix = rSet;}
     const OUString& GetSuffix() const { return sSuffix;}
     void            SetListFormat(const OUString& rSet) { sListFormat = rSet; }
-    const OUString& GetListFormat() const { return sListFormat; }
+    bool            HasListFormat() const { return sListFormat.has_value(); }
+    const OUString& GetListFormat() const { return *sListFormat; }
 
     void                    SetCharFormatName(const OUString& rSet){ sCharStyleName = rSet; }
     virtual OUString        GetCharFormatName()const;

sw/source/core/doc/number.cxx

@@ -644,9 +644,9 @@ OUString SwNumRule::MakeNumString( const SwNumberTree::tNumberVector & rNumVecto
         {
             css::lang::Locale aLocale( LanguageTag::convertToLocale(nLang));
 
-            OUString sLevelFormat = rMyNFormat.GetListFormat();
-            if (!sLevelFormat.isEmpty())
+            if (rMyNFormat.HasListFormat())
             {
+                OUString sLevelFormat = rMyNFormat.GetListFormat();
                 // In this case we are ignoring GetIncludeUpperLevels: we put all
                 // level numbers requested by level format
                 for (SwNumberTree::tNumberVector::size_type i=0; i <= nLevel; ++i)

sw/source/core/unocore/unosett.cxx

@@ -1335,11 +1335,12 @@ uno::Sequence<beans::PropertyValue> SwXNumberingRules::GetPropertiesForNumFormat
     aPropertyValues.push_back(comphelper::makePropertyValue("Suffix", aUString));
 
     //listformat
-    aUString = rFormat.GetListFormat();
-    aPropertyValues.push_back(comphelper::makePropertyValue("ListFormat", aUString));
+    if (rFormat.HasListFormat())
+    {
+        aPropertyValues.push_back(comphelper::makePropertyValue("ListFormat", rFormat.GetListFormat()));
+    }
 
     //char style name
-
     aUString.clear();
     SwStyleNameMapper::FillProgName( rCharFormatName, aUString, SwGetPoolIdFromName::ChrFmt);
     aPropertyValues.push_back(comphelper::makePropertyValue("CharStyleName", aUString));

sw/source/filter/ww8/wrtw8num.cxx

@@ -494,7 +494,7 @@ void MSWordExportBase::NumberingLevel(
     const vcl::Font* pBulletFont=nullptr;
     rtl_TextEncoding eChrSet=0;
     FontFamily eFamily=FAMILY_DECORATIVE;
-    if (!rRule.Get(nLvl).GetListFormat().isEmpty())
+    if (rRule.Get(nLvl).HasListFormat())
     {
         // Nothing to construct: we have it already
         sNumStr = rRule.Get(nLvl).GetListFormat();