On Wed, 24 Oct 2007 12:48:01 -0400, Jim Henderson wrote:

> The problem doesn't
> start in the software development houses, it starts at school when
> students are learning how to code and are taught bad habits from the
> start.

As an example, I remember a core component of a popular server OS that 
would, under certain circumstances, display negative disk space free.

This looks quite stupid when it happens - since clearly that's not a 
possible situation.  The bug was deemed to be a "cosmetic" error and was 
never fixed.  Customers looked at it and said "if that sort of error 
exists, what am I *not* seeing?"

To someone with a little background in C (the language used for the tool 
in question), it's clear that the problem was either (a) sloppy 
declaration of the variable type, letting the default signed value be 
used rather than specifying an unsigned data type or (b) poor use of the 
formatting specification when the data was output, using a signed output 
type when an unsigned data type was used.

Either way is not good.  It's an easy mistake to make, but if they've 
internalized the need to be specific, then this sort of thing wouldn't 
happen.

Jim

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