Re: [PATCH v9 0/4] MR6855: server: Fix renaming file to a hardlink of itself.

[Jinoh Kang (＠iamahuman)]

Jinoh Kang (@iamahuman) commented about server/fd.c:
>      ((fd->options & FILE_DELETE_ON_CLOSE) ? FILE_DISPOSITION_DELETE : 0);
>
> }
>
> +/* rename the same file, dealing with casefolding and possibly different hardlinks to it */
> +static void rename_same_file( const char *src, const char *dst, int is_dir )
> +{
> - static const char tmpname_fmt[] = ".wine-rename-tmp-%08x";
> - static unsigned tmp_value;
> -
> - char *dirname, tmpname[sizeof(tmpname_fmt) + 4 /* remaining of %08x */];
> - const char *srcname, *dstname = strrchr( dst, '/' ) + 1;
> - struct stat st, st2;
> - int dirfd, res = 0;
> - unsigned i;
> -

You should check for `"/"`; otherwise dstname will be empty and `MoveFile( "\??\unix\", "\??\unix\" )` fails with a cryptic error `ERROR_FILE_NOT_FOUND`. Also, move `dstname` assignment below the / check where we have guaranteed that dst is not `"/"`:

```suggestion:-0+0

if (!strcmp( src, "/" ) || !strcmp( dst, "/" ))
    {
        set_error( STATUS_ACCESS_DENIED );
        return;
    }

dstname = strrchr( dst, '/' ) + 1;
```