urg, backing out, this breaks attaching files with non-ascii names on non-windows platforms

mailnews/compose/src/nsMsgCompose.cpp

@@ -3517,8 +3517,16 @@ nsresult nsMsgCompose::AttachmentPrettyName(const char* url, PRUnichar** _retval
     char * leafName = fileSpec.GetLeafName();
     if (leafName && *leafName)
     {
+#ifdef MOZ_UNICODE
         /* file URL is now in UTF-8 */
         *_retval = ToNewUnicode(NS_ConvertUTF8toUCS2(leafName));
+#else
+        nsAutoString tempStr;
+        nsresult rv = ConvertToUnicode(nsMsgI18NFileSystemCharset(), leafName, tempStr);
+        if (NS_FAILED(rv))
+          tempStr.AssignWithConversion(leafName);
+      *_retval = ToNewUnicode(tempStr);
+#endif /* MOZ_UNICODE */
       nsCRT::free(leafName);
       return NS_OK;
     }