return ISO8859-1 from wxLocale::GetSystemEncoding() for C locale, as in trunk, otherwise wxCSConv with default encoding doesn't work at all

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@54700 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/intl.cpp

@@ -2504,7 +2504,13 @@ wxFontEncoding wxLocale::GetSystemEncoding()
         // (a.k.a. US-ASCII) which is arguably a bug but keep it like this for
         // backwards compatibility and just take care to not return
         // wxFONTENCODING_DEFAULT from here as this surely doesn't make sense
-        if ( enc != wxFONTENCODING_MAX && enc != wxFONTENCODING_DEFAULT )
+        if ( enc == wxFONTENCODING_DEFAULT )
+        {
+            // we don't have wxFONTENCODING_ASCII, so use the closest one
+            return wxFONTENCODING_ISO8859_1;
+        }
+
+        if ( enc != wxFONTENCODING_MAX )
         {
             return enc;
         }