john@jetson.upma.md.us (John Owens) (02/22/90)
[If you haven't already seen this, here's the bug in the CCS7 software.]
From: kent@wsl.dec.com, via db@cs.purdue.edu, via RISKS
Subject: AT&T Bug
Date: Fri Jan 19 12:18:33 1990
This is the bug that cause the AT&T breakdown
the other day (no, it wasn't an MCI virus):
In the switching software (written in C), there was a long
"do . . . while" construct, which contained
a "switch" statement, which contained
an "if" clause, which contained a
"break," which was intended for
the "if" clause, but instead broke from
the "switch" statement.
["break" never breaks an "if", only "switch"es, "do"s, and "while"s.]ted@uunet.uu.net (Ted Schroeder) (03/02/90)
john@jetson.upma.md.us (John Owens) writes: >[If you haven't already seen this, here's the bug in the CCS7 software.] >This is the bug that cause the AT&T breakdown >the other day (no, it wasn't an MCI virus): >In the switching software (written in C), there was a long >"do . . . while" construct, which contained > a "switch" statement, which contained > an "if" clause, which contained a > "break," which was intended for > the "if" clause, but instead broke from > the "switch" statement. >["break" never breaks an "if", only "switch"es, "do"s, and "while"s.] If this is the real bug did anyone else notice that lint would have caught it? I guess we know what AT&T thinks about "proving programs correct" if they don't even lint their code, eh? Ted Schroeder ted@Ultra.com Ultra Network Technologies ...!ames!ultra!ted 101 Daggett Drive San Jose, CA 95134 408-922-0100 Disclaimer: I don't even believe what I say, why should my company?