Do not use blank lines in /etc/passwd

[Dan Hoey]

    Date: Mon, 25 Aug 86 11:15:24 edt
    From: sscalsk at nswc-wo.arpa

    Anybody ever had a blank line as the first line in your password
    file? It happened to me a few weeks ago and the system would not
    let any user at all log on. Su did not work either....

At least in vanilla 4.2, having blank lines anywhere in your password
file opens a security hole that I will forbear to discuss on this list.
I have not verified this on other systems, but I advise you to stick to
the standard format.  If you want to insert blank lines for readability
(which is how I discovered the bug) use nearly-blank lines like

x:*:0:0:                                                             ::

assuming that "x" is not a user on your system.

Dan Hoey
hoey at NRL-AIC.ARPA