crashtesting: assert seen with forum-mso-en4-747641.xlsx with LCID F6E0B

see on export to ods

input .xlsx contains a LCID of F6E0B

<numFmt numFmtId="169" formatCode="_-[$£-F6E0B]* #,##0.00_-;\-[$£-F6E0B]* #,##0.00_-;_-[$£-F6E0B]* &quot;-&quot;??_-;_-@_-"/>

Change-Id: I543164dba4cc8b1c86508a3e3e39b43900c06484
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/144321
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
diff --git a/svl/source/numbers/zforlist.cxx b/svl/source/numbers/zforlist.cxx
index c43e124..cee75fc 100644
--- a/svl/source/numbers/zforlist.cxx
+++ b/svl/source/numbers/zforlist.cxx
@@ -3991,7 +3991,10 @@ const NfCurrencyEntry* SvNumberFormatter::GetCurrencyEntry( bool & bFoundBank,
        }
        else
        {
            eExtLang = LanguageType((nExtLang < 0) ? -nExtLang : nExtLang);
            if (nExtLang < 0)
                nExtLang = -nExtLang;
            SAL_WARN_IF(nExtLang > 0xFFFF, "svl.numbers", "Out of range Lang Id: " << nExtLang << " from input string: " << OUString(rExtension));
            eExtLang = LanguageType(nExtLang & 0xFFFF);
        }
    }
    else
diff --git a/xmloff/source/style/xmlnumfe.cxx b/xmloff/source/style/xmlnumfe.cxx
index a2938b1..01367fe 100644
--- a/xmloff/source/style/xmlnumfe.cxx
+++ b/xmloff/source/style/xmlnumfe.cxx
@@ -362,7 +362,8 @@ void SvXMLNumFmtExport::WriteCurrencyElement_Impl( const OUString& rString,
        sal_Int32 nLang = o3tl::toInt32(rExt, 16);
        if ( nLang < 0 )
            nLang = -nLang;
        AddLanguageAttr_Impl( LanguageType(nLang) );          // adds to pAttrList
        SAL_WARN_IF(nLang > 0xFFFF, "xmloff.style", "Out of range Lang Id: " << nLang << " from input string: " << OUString(rExt));
        AddLanguageAttr_Impl( LanguageType(nLang & 0xFFFF) );          // adds to pAttrList
    }

    SvXMLElementExport aElem( rExport,