Re: [PATCH] block/curl: use strlen instead of strchr

[Vladimir Sementsov-Ogievskiy]

On 01.07.24 09:34, Vladimir Sementsov-Ogievskiy wrote:
> On 29.06.24 09:20, Michael Tokarev wrote:
> > On 6/28/24 08:49, Vladimir Sementsov-Ogievskiy wrote:
> > > We already know where colon is, so no reason to search for it. Also,
> > > avoid a code, which looks like we forget to check return value of
> > > strchr() to NULL.
> > >
> > > Suggested-by: Kevin Wolf <kwolf@redhat.com>
> > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
> > > ---
> > >
> > > This replaces my patch
> > >    [PATCH] block/curl: explicitly assert that strchr returns non-NULL value
> > > Supersedes: <20240627153059.589070-1-vsementsov@yandex-team.ru>
> > >
> > >   block/curl.c | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/block/curl.c b/block/curl.c
> > > index 419f7c89ef..d03bfe4817 100644
> > > --- a/block/curl.c
> > > +++ b/block/curl.c
> > > @@ -219,7 +219,7 @@ static size_t curl_header_cb(void *ptr, size_t size, size_t 
> > > nmemb, void *opaque)
> > >           && g_ascii_strncasecmp(header, accept_ranges,
> > >                                  strlen(accept_ranges)) == 0) {
> > > -        char *p = strchr(header, ':') + 1;
> > > +        char *p = header + strlen(accept_ranges);
> > >           /* Skip whitespace between the header name and value. */
> > >           while (p < end && *p && g_ascii_isspace(*p)) {
> >
> > Heck.  All these strlen()s look ugly, especially in the
> > loop iterations..
>
> I expect that strlen of string constant is calculated in compilation time.
>
> My aim was to fix Coverity complain (I don't see this complain in public qemu 
> coverity project, that's why I don't specify CID in commit message), not to 
> rewrite the whole function. So I'd prefer Kevein's suggesting which is both 
> minimal and makes the code obviously correct.. The only simpler thing is to 
> mark the problem false-positive in Coverity.


Upd: I missed that you sent a patch, this changes things. Of course, you code 
looks nicer than old one.

--
Best regards,
Vladimir