Re: kernel32: fix incorrect lastpart in GetFullPathNameA with DBCS

[Akihiro Sagawa]

On Thu, 09 Oct 2014 12:03:15 -0500, Aric Stewart wrote:
> ---
>  dlls/kernel32/path.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Hi Aric,
Thank you for pointing this out, but unfortunately this seems not to be perfect.
Because certain DBCS trail byte range is overlapped its lead byte range
[1].

To demonstrate this issue, I attached additional test. The first case
(0x955c,0x97a0=表裏) is now pass by your patch, but the second one
(0x838f,0x8343,0x8393=ワイン) is failure.

In my opinion, the solution is looking up the path separator from the
beginning of the string like _mbsrchr() in msvcrt.

If you have a further question about this, please contact me.

[1] For CP 932 (Japanese Shift JIS),
   Double byte character:
       Lead byte (first byte):   0x81-0x9f or 0xe0-0xfc, and
       Trail byte (second byte): 0x40-0x7e or 0x80-0xfc.
   Single byte character: 0x00-0x7f, 0xa1-0xdf.

Regards,
Akihiro Sagawa

kernel32: fix incorrect lastpart in GetFullPathNameA with DBCS

[Aric Stewart]

On 10/10/14, 10:45 AM, Akihiro Sagawa wrote:
> On Thu, 09 Oct 2014 12:03:15 -0500, Aric Stewart wrote:
> > ---
> >   dlls/kernel32/path.c | 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
>
> Hi Aric,
> Thank you for pointing this out, but unfortunately this seems not to be perfect.
> Because certain DBCS trail byte range is overlapped its lead byte range
> [1].
>
> To demonstrate this issue, I attached additional test. The first case
> (0x955c,0x97a0=表裏) is now pass by your patch, but the second one
> (0x838f,0x8343,0x8393=ワイン) is failure.
>
> In my opinion, the solution is looking up the path separator from the
> beginning of the string like _mbsrchr() in msvcrt.
>
> If you have a further question about this, please contact me.
>
> [1] For CP 932 (Japanese Shift JIS),
>     Double byte character:
>         Lead byte (first byte):   0x81-0x9f or 0xe0-0xfc, and
>         Trail byte (second byte): 0x40-0x7e or 0x80-0xfc.
>     Single byte character: 0x00-0x7f, 0xa1-0xdf.
>
> Regards,
> Akihiro Sagawa

Hello Akihiro-san,

Thank you very much for the investigation here.  It is very helpful!  I am not as familiar with SJIS as I thought.

I do not have a lot of time.  If you feel like you can fix this properly then I am happy to have you fix it.  If you are also busy then I will try to get some time to put together a proper fix. 

thanks again!
-aric