[sane-devel] VueScan and SANE

[abel deuring]

Maurice Hilarius wrote:

> To make a long story short, I tried VueScan, and it failed miserably with
> my Microtek X12USL scanner.
> I was finally able to get this scanner working to a fairly good degree with
> SANE.
> 
> During my attempts to make this work I contacted the author, (and
> apparently the owner of the VueScan company), as his literature claimed
> that this scanner was supported. I quickly found out that he had, in fact,
> never tried this scanner, and he was less than helpful, and, quite frankly,
> very rude.
> 
> As for the Open Source side, I think he needs to learn a bit about software
> and Open Source, as he seemed quite hostile about that, even though he
> takes liberally from SANE for his product.
> In looking at what he provides I believe that he is likely breaking the GPL
> already..

Maurice,

I don't think that Ed Hamrick breaks the Sane license. From
sanei_scsi.c:

    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.
    [...]
    As a special exception, the authors of SANE give permission for
    additional uses of the libraries contained in this release of SANE.

    The exception is that, if you link a SANE library with other files
    to produce an executable, this does not by itself cause the
    resulting executable to be covered by the GNU General Public
    License.  Your use of that executable is in no way restricted on
    account of linking the SANE library code into it.

    This exception does not, however, invalidate any other reasons why
    the executable file might be covered by the GNU General Public
    License.

I joined the Sane project relatively late, so I don't know the reason
for this exception. My guess is that the intention was to allow linking
of Sane backends against an application like Star office (before the
latter was GPL'ed, of course).

But I am not very happy with the restriction to static linkage. A few
months ago, Jose Paulo Moitinho de Almeida reported a problem using
Vuescan with a Minolta film scanner. The debug output provided by Ze
Paulo's showed that sanei_scsi needed a better handling of status codes
returned by the scanner; things like INTERMEDIATE GOOD were not properly
handled. So I fixed this in sanei_scsi.c, but we could not test the fix,
because Ed Hamrick did not send an updated executable to Ze Paulo... 

I hope that I don't open a can of worms -- but the LGPL has good
provisions to handle this situation: It allows dynamic linking; and if a
program uses statically linked LGPL'ed libraries, users must receive
object files of the proprietary componenents so that they can easily
link a new executable with improved LGPL'ed libraries. 

Abel