Missing Information in the Text Version of Ask a Question Emails

[cmb]

If a person selects the Ask a Question About This Product option on a product detail page, the site owner receives an email. That email can be either in HTML format or plain text. That option is selected at Administrator > Components > VirtueMart > Configuration > Shop tab > Emails Settings.

If HTML Mail is selected, the received email contains a line of the form:
A question was asked by <correspondent's name> (<correspondent's email address>)

If Text Mail is chosen, the equivalent line is:
A question was asked by ()

The parentheses appear but the correspondent's name and email are missing in the plain text version. I didn't see any bug report in the tracker that mentioned this omission.

Joomla 2.5.7, VirtueMart 2.0.12b