[ros-kernel] implementation question

[Royce M. I. <ro...@ev...>]

I was reading about shell32.DoEnvironmentSubst(), and I came across an
interesting comment in MS documentation:

Parameters must contain valid values that are not NULL. You are responsibile
for validating these values. If you do not validate it, you will experience
unexpected results.

Here's the link where that comment can be found:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/shellcc/pla
tform/shell/reference/functions/doenvironmentsubst.asp

Now, my question is this: what is the harm in checking for invalid params,
and returning failure instead of just letting the OS do it's "unexpected"
thing?

Royce3