Re: [PATCH 2/6] ERR_PTR: add ERR_OR_0_PTR

[Al Viro <viro@ZenIV.linux.org.uk>]

On Mon, May 19, 2008 at 07:55:04AM +0200, Christoph Hellwig wrote:
> On Mon, May 19, 2008 at 12:01:07AM +0200, Marcin Slusarz wrote:
> > Some codepaths call ERR_PTR with possibly 0 argument, which is not
> > a valid errno and rely on conversion from 0 to NULL pointer.
> > Add ERR_OR_0_PTR function which accepts errnos and 0 as an argument.
> 
> Sorry, no.  ERR_PTR(0) is perfectly valid, you just don't want to return
> the actualy value.  E.g. we have a common idiom of:
> 
> 	some_ptr = ERR_PTR(err);
> 	if (IS_ERR(some_ptr))
> 		goto out_handle_err;
> 
> and obsfucating this with new syntactic sugar is not a good idea.

Um... Could somebody explain WTF is wrong with declaring that ERR_PTR(0)
is NULL?  Sure, if we run into a target where converting non-constant
integer with value zero to void * does not result in null pointer, we'll
need to adjust ERR_PTR().  So.  Fscking.  What?
	a) it's not a lot of adjustment, to start with
	b) any such target will require much more work on porting anyway;
this part will be trivial.