Re: [perf PATCH 3/3] Fix double fclose() on do_write(fd, xxx) failure

[Thomas Jarosch <thomas.jarosch@intra2net.com>]

On Friday, 25. January 2013 13:01:51 you wrote:
> Em Fri, Jan 25, 2013 at 11:22:17AM +0100, Thomas Jarosch escreveu:
> > cppcheck reported:
> > [util/header.c:983]: (error) Used file that is not opened.
> > 
> > Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
> > ---
> > 
> >  tools/perf/util/header.c | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
> > index 7b24cf3..30745c2 100644
> > --- a/tools/perf/util/header.c
> > +++ b/tools/perf/util/header.c
> > @@ -955,6 +955,7 @@ static int write_topo_node(int fd, int node)
> > 
> >  	}
> >  	
> >  	fclose(fp);
> > 
> > +	fp = NULL;
> 
> Ok, but what is the behaviour of fclose(NULL)? Is it defined?
> 
> - Arnaldo

Grrr, this is undefined behavior. Sorry. I always thought this
is defined like free(NULL) but apparently it is not.

I'll send another version of the patch and also write to the
man page maintainer to add a small hint to the fclose() man page.

Thomas