MAJOR BUG (what a hooter!)

[David Canzi]

Yes, you can call it a feature if you want, since it was obviously
deliberately put there.
But, if the first five or the last five lines of /etc/passwd contain a userid
or encrypted password ending in "vi", "ex", "vx", or "ei", then using "vipw"
becomes a risky business.
This feature is a trap waiting to spring on the unwary, and such features are
unwelcome in any programming language, operating system, or text editor.  It
obviously serves a purpose, but some safer way ought to be found to accomplish
this purpose.