Date: Sat, 25 Aug 2001 10:22:38 +0300
From: "Eli Zaretskii" <eliz AT is DOT elta DOT co DOT il>
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To: acottrel AT ihug DOT com DOT au
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In-reply-to: <00de01c12d06$82e2cd40$0a02a8c0@acceleron> (acottrel@ihug.com.au)
Subject: Re: Read 3F00 STDIN problem on Win 2K ( was Re: Fseek on STDIN problem on Win 2K)
References:  <00de01c12d06$82e2cd40$0a02a8c0 AT acceleron>
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> From: "Andrew Cottrell" <acottrel AT ihug DOT com DOT au>
> Date: Sat, 25 Aug 2001 11:37:13 +1000
> 
> A quick fix is outlined below thanks to Charles finding that a fix for
> is_executable() is to add a call to 4201 with an offset of 0 after the 3F00
> call, this also fixes _read(). If this is okay I can also include a similar
> change to d_read.c and int86.c
> 
> What do people think about this?
[...]
> +   if(use_lfn && _osmajor == 5 && _get_dos_version(1) == 0x532)
> +   {
> +     /* Windows 2000 or XP; or NT with LFN TSR.        Windows 2000 behaves
> +        badly when using 3F00 call. We need to seek to the current
> +        position in order for subseqent calls to work. */
> +     memset(&r,0,sizeof(r));
> +     r.x.ax = 0x4201;     /* 4201h current file position */
> +     r.x.bx = handle;     /*  BX = file handle */
> +     r.x.cx = r.x.dx =0;    /* CX:DX = (signed) offset from origin of new file position */
> +     __dpmi_int(0x21, &r);

Is 3F00 broken only under LFN?  What happens if you set LFN=n on W2K:
does it work then?

If it's broken without LFN as well, you need to drop the test for
_USE_LFN in these patcehs.

And that memset to zero out the registers' struct is not needed when
you call __dpmi_int (it zeroes out the important parts for you).

Otherwise, the changes look fine.  Thanks!