tdf#56738: fix encoding in comments in doc files (>= Word 97)

See https://bugs.documentfoundation.org/show_bug.cgi?id=56738#c3

Change-Id: I8dbab3fe76b2c2d83cbb07509fabe9f784664c03
Reviewed-on: https://gerrit.libreoffice.org/73088
(cherry picked from commit fd01ddd3)
Reviewed-on: https://gerrit.libreoffice.org/73157
Tested-by: Jenkins
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>

sw/source/filter/ww8/ww8par.cxx

@@ -2809,7 +2809,9 @@ rtl_TextEncoding SwWW8ImplReader::GetCurrentCharSet()
     rtl_TextEncoding eSrcCharSet = m_eHardCharSet;
     if (eSrcCharSet == RTL_TEXTENCODING_DONTKNOW)
     {
-        if (!m_aFontSrcCharSets.empty())
+        if (!m_bVer67)
+            eSrcCharSet = GetCharSetFromLanguage();
+        else if (!m_aFontSrcCharSets.empty())
             eSrcCharSet = m_aFontSrcCharSets.top();
         if ((eSrcCharSet == RTL_TEXTENCODING_DONTKNOW) && m_nCharFormat >= 0 && static_cast<size_t>(m_nCharFormat) < m_vColl.size() )
             eSrcCharSet = m_vColl[m_nCharFormat].GetCharSet();