Hi Peter,

Thanks for forwarding these observations.  We use Scribus for the MagPi 
(Raspberry Pi users magazine).  Several people have been running Scribus 1.4.1 
on their Raspberry Pi (ARM Debian Wheezy with floating point enabled).  We 
would like to upgrade to Scribus version 1.4.2 or 1.4.3, to use colour 
management options needed for correct colour representation of the printed 
magazine.  I am happy to provide patches for 1.4.3, but as you say we really 
need someone from the Scribus development team to be involved in the patching 
decisions.

Thanks and best regards,

Will




________________________________
 From: peter green <[email protected]>
To: William Bell <[email protected]> 
Cc: Mike Thompson <[email protected]>; ARM <[email protected]>; 
[email protected]; [email protected] 
Sent: Wednesday, 21 August 2013, 2:12
Subject: scribus on arm linux (was: Re: Fw: Raspbian: building Scribus)
 

William Bell wrote:
> Hi Peter,
> 
> Did you push the problem with Scribus back to the Scribus developers?
As a general rule I don't deal with upstreams directly unless it's for a 
program I use myself heavilly and/or am one of the debian matainers for. IMO 
the responsibility for knowing how best to deal with upstream and knowing what 
patches from debian they will and wont want lies with the maintainer of the 
debian packages.

In this case though given the lack of any action by the debian maintainer on 
the latest bug I filed I think it's best to keep upstream in the loop. I'm 
ccing them (and a few other places) on this mail.

Note that I do not personally use scribus.

> It looks like Plugwash fixed the issue upstream:
> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=659916
Afaict bug reports have been filed over issues with scribus on arm  on several 
occasions. All the ones I submitted were variants on the theme of "you need to 
be more careful about mixing qreal and double". From reading the debian 
changelog it looks like the maintainer pushed at least some of them upstream.

For anyone reading this who is not familiar with the issue the underlying 
problem is that qt developers chose to define qreal differently on arm from on 
other platforms. On most platforms qreal is defined as double but on arm 
platforms it is defined as float. I assume this was done to give better 
performance, especially on earlier arm hardware that did not have usable 
hardware floating point, whatever the original reason it seems to be a 
descision we are laregly stuck with*. Therefore qt application developers have 
to be careful about how they mix qreal and double if they want their code to 
work on arm.
>   The problem with double and float seems to be worse in 1.4.3.  There are 
>several references to QVector<double> and QList<double>.  The fix is not as 
>straightforward as hoped, since they have some overridden functions with 
>QVector<double> and QVector<float> inside Scribus.
I was able to get 1.4.2 to build with a patch that I posted at 
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=707882 . However the patch was 
far more intrusive than previous patches I have prepared and I am not confident 
in it's correctness. It really needs someone who understands the code in 
question to check it before it is applied. The patch looks basically the same 
as the one the fedora guy posted.

This issue is blocking scribus 1.4.2 from reaching debian (and hence raspbian) 
jessie.

I have not looked at 1.4.3 partly because it's not in debian yet and partly 
because I only look at build failures when i'm bored or when they are blocking 
something I care about.

* Unless we want to break binary compatibility with upstream but I really do 
not think going down that road is a good idea.

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