Re: [PATCH setup] Avoid stringop-overflow warning with gcc8

[Jon Turney <jon dot turney at dronecode dot org dot uk>]

On 12/10/2018 16:58, Corinna Vinschen wrote:
> On Oct 12 16:43, Jon Turney wrote:
[...]
> > diff --git a/desktop.cc b/desktop.cc
> > index 927c02f..d003e91 100644
> > --- a/desktop.cc
> > +++ b/desktop.cc
> > @@ -107,7 +107,8 @@ start_menu (const std::string& title, const std::string& target,
> >   			      issystem ? CSIDL_COMMON_PROGRAMS :
> >   			      CSIDL_PROGRAMS, &id);
> >     SHGetPathFromIDList (id, path);
> > -  strncat (path, "/Cygwin", MAX_PATH);
> > +  strncat (path, "/Cygwin", MAX_PATH - strlen(path));
>
> Shouldn't that be
>
>       strncat (path, "/Cygwin", MAX_PATH - strlen(path) - 1);
>
> ?

Yes!  I have no idea what I was thinking!

Thanks.

> "If src contains n or more bytes, strncat() writes n+1 bytes to dest  (n
>   from  src plus the terminating null byte).  Therefore, the size of dest
>   must be at least strlen(dest)+n+1."