Re: Problems with .PDFPIC caused by pdfinfo

[Heinz-Jürgen Oertel]

Am Dienstag, 21. September 2021, 13:51:12 CEST schrieb Heinz-Jürgen Oertel:
> Am Montag, 20. September 2021, 21:39:49 CEST schrieb Keith Marshall:
> > On 20/09/2021 19:22, Dave Kemper wrote:
> > > Hi Heinz-Jürgen,
> > > 
> > > Thanks for debugging and submitting a fix for this problem!
> > 
> > Except that it's not really the most appropriate solution; that was 
> > proposed four years ago...
> > 
> > > In general, when proposing changes to the groff code base, it's best
> > > to open a bug report ...
> > 
> > ...and Bertrand opened a (belated) ticket:
> > https://savannah.gnu.org/bugs/index.php?55107
> > 
> > which has shown no activity since; (so even open tickets aren't immune 
> > to fading into obscurity).
> > 
> > > Regarding the specific change you've proposed, there may be some
> > > resistance to using a grep option that's not part of the POSIX
> > > standard for the command.  I'm not sure how widely implemented -a is,
> > > or what equivalent solution might be more portable.
> > 
> > I would go even further ... groff should *not* be calling out to 
> > external tools, such as grep — much less pdfinfo — from within core 
> > code, in a manner which requires use of unsafe mode, *especially* when 
> > core code to achieve the required functionally has been awaiting 
> > integration for a number of years!
> 
> For me too it would be a better solution to not calling external tools, even 
> that's part of the linux/unix philosophy.
> As you found out, this small problem does exist for years already. I don't 
> remember exactly, but I looked already at the pdfinfo code, but was not able 
> to correct it. It seems to be only the pdfinfo used in OpenSuse. 
> 
>  Posix grep
> https://www.unix.com/man-page/posix/1P/grep/
> does not know the -a or --text option.
>  
> Regards
>       Heinz

I did some more research. The result, it's not "pdfinfo" it is Imagemagick 
"convert".
I mostly use jpg file converted to pdf by "convert".
The example file "Selz.pdf"

% pdfinfo Selz.pdf | hexdump -xc
0000000    6954    6c74    3a65    2020    2020    2020    2020    2020
0000000   T   i   t   l   e   :                                        
0000010    5300    6500    6c00    7a00    0000    410a    7475    6f68
0000010  \0   S  \0   e  \0   l  \0   z  \0  \0  \n   A   u   t   h   o
0000020    3a72    2020    2020    2020    2020    6820    7474    7370
0000020   r   :                                      h   t   t   p   s
   ...

as one can see, there are \0 chars already in the title.
Looking at the PDF:

/Title <00530065006C007A0000>
/CreationDate (D:20210914095154)
/ModDate (D:20210914095154)
/Author (https://imagemagick.org)
/Producer (https://imagemagick.org)


you see, the \0 chars are already there.
What can I do?

 Regards
    Heinz