Subject: Re: [PATCH 05/15] name-rev: use sizeof(*ptr) instead of sizeof(type) in allocation

From: SZEDER Gábor <[email-masked]>
Date: Fri, 20 Sep 2019 17:40:49 +0200

On Fri, Sep 20, 2019 at 11:11:02AM -0400, Derrick Stolee wrote:
> On 9/19/2019 5:47 PM, SZEDER Gábor wrote:
> > Signed-off-by: SZEDER Gábor <[email-masked]>
> > ---
> >  builtin/name-rev.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/builtin/name-rev.c b/builtin/name-rev.c
> > index e406ff8e17..dec2228cc7 100644
> > --- a/builtin/name-rev.c
> > +++ b/builtin/name-rev.c
> > @@ -98,7 +98,7 @@ static void name_rev(struct commit *commit,
> >  	}
> >  
> >  	if (name == NULL) {
> > -		name = xmalloc(sizeof(rev_name));
> > +		name = xmalloc(sizeof(*name));
> 
> Is this our preferred way to use xmalloc()? If so, then
> I've been doing it wrong and will correct myself in the
> future.

I seem to remember that Peff mentioned in a commit message that this
is the preferred way, but can't find it at the moment.  Anyway, when
using 'sizeof(*ptr)' the type is inferred by the compiler, but when
using 'sizeof(type)' then we have to make sure that 'type' is indeed
the right type.

Besides, that 'rev_name' should have been spelled as 'struct rev_name'
to begin with.