Entity conversion glitch?

[Petite Abeille]

Hello,

Given the following text:

under a license from AT&T; however, others were based on BSD instead.

Daring Fireball's Markdown Dingus produces:

<p>under a license from AT&T; however, others were based on BSD  
instead.</p>

Note how the '&' is not escaped to '&amp;'.

Bug? Feature?

Thanks in advance.

Kind regards,

PA.