Re: [PATCH RFC] err.h: document that PTR_ERR should only be used if IS_ERR returns true

[Al Viro]

On Mon, Oct 15, 2018 at 11:37:08AM +0200, Alessandro Rubini wrote:

> OTOH I admit you can compare any value with -EINVAL, after PTR_ERR.
> But in general you first detect the error condition and then split
> among error (or print a message according to the exact value.

        if (IS_ERR(p) && PTR_ERR(p) == -ENOENT)
instead of
        if (p == ERR_PTR(-ENOENT))

is ugly, obfuscating what's going on for no good reason and I'm going
to keep killing those every time I run into one...