Re: [PATCH v1 1/2] enter.c: Use wmem*() functions with wide-character strings

On Fri, Feb 13, 2026 at 02:36:29PM +0100, Alejandro Colomar wrote:
> Hi Greg,
> 
> On 2026-02-13T08:34:14+0100, Greg KH wrote:
> > On Thu, Feb 12, 2026 at 11:56:19PM +0100, Alejandro Colomar via Mutt-dev wrote:
> > > This avoids an explicit size multiplication, which can overflow the
> > > calculation.
> > > 
> > > Signed-off-by: Alejandro Colomar <[email protected]>
> > > Cherry-picked-from: neomutt.git 7df621a105e2 (2024-05-09, "Use wmem*() functions with wide-character strings")
> > > [alx: Adapted diff and message to mutt(1)]
> > > Signed-off-by: Alejandro Colomar <[email protected]>
> > > ---
> [...]
> > > @@ -175,7 +176,7 @@ static void replace_part (ENTER_STATE *state, size_t from, char *buf)
> > >    if (savelen)
> > >    {
> > >      savebuf = safe_calloc (savelen, sizeof (wchar_t));
> > > -    memcpy (savebuf, state->wbuf + state->curpos, savelen * sizeof (wchar_t));
> > > +    wmemcpy (savebuf, state->wbuf + state->curpos, savelen);
> > 
> > If there was going to be an overflow, safe_calloc() would have crashed
> > the system, so we can "know" that if it returns, it's all good so there
> > will not be any overflow happening.
> 
> True; and I've made that same argument elsewhere; I don't understand why
> I wrote that in the commit message.  It was a long time ago...
> 
> > 
> > So I don't think this patch actually does anything except make code
> > checking tools happy because it can not actually read the logic :)
> 
> Actually, it improves the readability.  I would do it even if only for
> that.  Also, wmemcpy(3) is more type-safe, as it doesn't use void*.

No objection if you do it for that, just don't claim it could "fix an
overflow" as people tend to freak out over stuff like that :)

thanks,

greg k-h