[sane-devel] Plustek backend: incorrect rounding

[Aurelien Jarno]

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Hello !

I am forwarding the following bug reported via the Debian BTS:

| In backend/plustek-usbimg.c, line 1363:
|
| if(!(a_bRegs[0x4e] =3D (u_char)ceil(dw / (4 * hw->wDRAMSize))))
|
| dw and hw->wDRAMSize are both integral types, meaning the division is
| done in integer arithmetic, the result is always rounded down instead of
| up, and the ceil() is left meaningless.

The following patch should fix that.

Aurelien


Index: sane-backends/backend/plustek-usbimg.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
RCS file:
/cvsroot/external/sane/sane-backends/backend/plustek-usbimg.c,v
retrieving revision 1.9
diff -u -1 -b -p -r1.9 plustek-usbimg.c
--- plustek-usbimg.c    2002/10/15 18:02:39     1.9
+++ plustek-usbimg.c    2002/12/06 19:57:07
@@ -1362,3 +1362,3 @@ static SANE_Int usb_ReadData( struct Plu
                {
-                       if(!(a_bRegs[0x4e] =3D (u_char)ceil(dw / (4 * hw->w=
DRAMSize))))		=09
+                       if(!(a_bRegs[0x4e] =3D (u_char)ceil(dw / (4.0 * hw-=
>wDRAMSize))))
                                a_bRegs[0x4e] =3D 1;

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