Empty txt-record not shown

[PhilippSelenium]

I have an avahid service configuration for a txt record that can be empty:

<txt-record value-format="binary-hex">fname=</txt-record>

In avahi-browse the field is shown:

txt = [... "fname=" ...]

In the BonjourBrowser the field is omitted if it is empty.

Is this a feature or a bug?