When displaying attachment download in tree, it contains garbage: (%<-size%>)

[Ronald Portier (Therp)]

I want to display for a portal kind of application a download link to an attachment in a tree. No further info on the attachment should be shown to the user.

This is my field definition in the view:

<field
name="attachment_ids"
colspan="3"
nolabel="1"
mode="tree"
readonly="1">
<tree
    editable="top"
    string="Attachments">
    <field
        name="type"
        invisible="1" />
    <field
        name="datas_fname"
        invisible="1" />
    <field
        name="datas"
        readonly="1"
        filename="datas_fname"/>
</tree>
</field>

When displaying attachment download in tree, it contains garbage: (%<-size%>)

The (%<-size%>) is apparantly a placeholder to put the size of the file.

The code that actualyly creates this text is in addons/web/static/src/js/formats.js:

324 case "binary":
325 var text = _t("Download"),
326 download_url = _.str.sprintf('/web/binary/saveas?session_id=%s&model=%s&field=%s&id=%d', openerp.connection.ses sion_id, options.model, column.id, options.id);
327 if (column.filename) {
328 download_url += '&filename_field=' + column.filename;
329 if (row_data[column.filename]) {
330 text = _.str.sprintf(_t("Download \"%s\""), openerp.web.format_value(
331 row_data[column.filename].value, {type: 'char'}));
332 }
333 }
334 return _.template('<a href="<%-href%>"><%-text%></a> (%<-size%>)', {
335 text: text,
336 href: download_url,
337 size: row_data[column.id].value
338 });

No idea how the size of the file is supposed to come from row_data[column.id].value, but iit is definitely not working.