avoiding incorrect code

[Satish Balay]

On Wed, 14 Jan 2009, Barry Smith wrote:

> > But imposing coding guidelines [which are unenforceable] to hide
> > compiler differences is a bad policy..
> 
>     This has nothing to do with compiler differences; just because
> some Fortran compilers use the bit pattern of 1 for .true. and some
> use -1 does not change the fact that a PetscTruth value of 0 is
> false while any other value is true.

Well our UserInterface [PETSC_TRUE,PETSC_FALSE] says one thing - but
now we are relying on a different UI [i.e only PETSC_FALSE is relavent
- PETSC_TRUE as currently defined is irrelavant - as everything else
other than PETSC_FALSE should be PETSC_TRUE]

I guess we can add in a python script to detect this uasage in code
[as we check for other things - doc related - in builddist anyway]

>  I don't know where the == PETSC_TRUE nonsense came from, it could be
> my fault. But the coding standard has been there for many years and most
> == PETSC_TRUE stuff was removed years ago.

Well I added in the code which was user-contributed. But I could
verywell have done it - as I didn't remember this code guideline [and
the reason for it..]

Satish