Re: [Qemu-devel] [PATCH RESEND 1/3] usb-ccid: make ccid_write_data_block() cope with null buffers

[Philippe Mathieu-Daudé]

Hi Markus, Gerd.

On 03/23/2017 11:08 AM, Markus Armbruster wrote:
> Gerd Hoffmann <address@hidden> writes:
>
> > On Do, 2017-03-23 at 13:41 +0100, Markus Armbruster wrote:
> > > Gerd Hoffmann <address@hidden> writes:
> > >
> > > >   Hi,
> > > >
> > > > >  oops, there are hard-coded calls with NULL/0. I suppose to fix clang
> > > > > warning, it would need to check if data != null for memcpy.
> > > >
> > > > I'd check for len > 0, and in that if branch we can also assert on data
> > > > == NULL and thereby check that len and data are consistent.
> > >
> > > If len is non-zero but data is null, memcpy() will crash just fine by
> > > itself, so why bother asserting.
> >
> > To make clang happy?  But maybe clang is clever enough to figure data
> > can't be null at that point in case we call memcpy with len != 0
> > only ...
>
> If Clang needs another hint to become happy, then an assertion is a fine
> way to provide it.

Apparently Clang isn't clever enough using an assertion.

I'll resend checking len.