Re: [PATCH] vvfat: refresh writing long filename

[Michael Tokarev]

18.01.2025 23:32, Volker Rümelin wrote:

> > +static unsigned write_lfn_part(uint8_t *dest, unsigned dsize,
> > +                               const gunichar2 *lptr, const gunichar2 *lend)
> > +{
> > +    unsigned i;
> > +    for(i = 0; i < dsize / 2 && lptr + i < lend; ++i) {
> > +        dest[i / 2 + 0] = lptr[i] & 0xff;
> > +        dest[i / 2 + 1] = lptr[i] >> 8;
> > +    }
>
> Hi Michael,
>
> this is not right. It's necessary to initialize the remaining elements
> of the name arrays.
> The rules are:
> If the file name length in characters is a multiple of 13 you are done.
> Otherwise the remaining unused LFN direntry name array elements have to
> be filled with one 0x0000 (a 16 bit 0) and the rest with 0xffff.

I wonder how it worked for me.  I tested it with linux and windows guests.
Hmm.

Well, it's rather trivial to fix this.  Lemme do just that..

> > +        lptr += write_lfn_part(entry->name1c, sizeof(entry->name1c), lptr, 
> > lend);
>
> I would use ARRAY_SIZE() instead of sizeof(). ARRAY_SIZE() is the number
> of elements an array can hold. You then don't have to remember the size
> of an array element.

sizeof() works fine here :)

/mjt