[sane-devel] scanimage does not recognize basic long options

[Karl Weber]

Hi Ralf,

On Saturday, 4 February 2023 18:06:41 CET Ralph Little wrote:
> The condition on SANE_OPTION_IS_SETTABLE(opt->cap) has been removed in
> version
> > 1.1.1 and this causes the problem.
> 
> I'm a bit confused by this comment. I thought that your issue was caused
> by the backend sending NULL.
> Which problem do you believe this causes? Or are you saying that the
> NULL options issue is revealed by this change? That is certainly possible.

Yes, you may also say that the NULL options issue has been revealed by this 
change. I didn't know, why this check has been removed and I don't know why it 
had been there beforehand. I am really new to sane! I started to look at the 
code two days ago. Before I was only an ignorant user of scanimage. So please 
excuse me.

But irrespective of the wording, are you going to do something about it? Or 
where would be the right place to fix this problem? Currently I have no idea, 
whether hplip-sane is open source and what the chances would be, to get a fix 
in there, if this would be the right place for a fix. I don't even know, 
whether it is part of the SANE API specification, that there must not be NULL 
options.

But even if it is a bug in hplip-sane, or the scanner-firmware itself, 
couldn't it be wise, to include a check against NULL options in scanimage? If 
my test revealed this problem, couldn't it show up with other backends as 
well? I have absolutely no idea, what and how you test before you release a 
new version of sane.

Regards
Karl