On 3/18/20 3:19 PM, Graeme wrote:
I currently use Linux Mint 18.3. Recently I upgraded to LyX 2.3.4.2 using the
PPA available at
http://ppa.launchpad.net/lyx-devel/release/ubuntu xenial main
Since this upgrade there have been problems with the display of EPS and PDF
graphics files in the main LyX editor window, and with the export of files
containing PNG and JPEG bitmap images.
These problems are not evident with LyX 2.3.4.3 on Windows 10, nor were they
present with LyX 2.3.3 on Linux Mint 18.3.
Specifically:
1. When including a graphic with either EPS or PDF format, the graphic is not
displayed in the main LyX editor window, but instead there is an outline box
with the EPS or PDF filename, and below it the error message: Error converting
to loadable format.
The graphic does appear correctly in a PDF file exported using either ps2pdf
or pdflatex.
2. When including a graphic with PNG or JPEG format, the graphic is displayed
correctly in the main LyX editor window, but when attempting to export the LyX
file to Postscript, PDF (using ps2pdf), or even just plain LaTeX, an error
pop-up window appears with the title:
LyX: Cannot convert file
and the message:
No information for converting png format files to eps. Define a converter in the preferences or No information for converting jpg format files to eps. Define a converter in the preferences.
The PNG and JPEG graphics do appear correctly in a PDF file exported using
pdflatex, but attempting to export with ps2pdf fails.
When exporting the Progress Log window shows the following messages for a
graphic in PNG format:
python -tt "/usr/share/lyx/scripts/convertDefault.py" png
"/tmp/lyx_tmpdir.fGfmcihv6288/lyx_tmpbuf0/2_home_graeme_Documents_GraphicsTestCircle.png" eps
"/tmp/lyx_tmpdir.fGfmcihv6288/lyx_tmpbuf0/2_home_graeme_Documents_GraphicsTestCircle.eps" convert:
not authorized `eps:/tmp/lyx_tmpdir.fGfmcihv6288/lyx_tmpbuf0/2_home_graeme_Documents_GraphicsTestCircle.eps'
@ error/constitute.c/WriteImage/1028.
/usr/share/lyx/scripts/convertDefault.py ERROR
Execution of "convert" failed.support/Systemcall.cpp (276): Systemcall: 'python -tt
"/usr/share/lyx/scripts/convertDefault.py" png
"/tmp/lyx_tmpdir.fGfmcihv6288/lyx_tmpbuf0/2_home_graeme_Documents_GraphicsTestCircle.png" eps
"/tmp/lyx_tmpdir.fGfmcihv6288/lyx_tmpbuf0/2_home_graeme_Documents_GraphicsTestCircle.eps"' finished with exit
code 1
Error: Cannot convert file
I get similar messages for a graphic file in JPEG format.
My suspicion is that BOTH the problems above may be linked to the use of
ImageMagick within convertDefault.py, but I am puzzled by the warning message
"convert: not authorized"
in the fragment above, suggesting it may be something to do with file or
folder permissions. However, this does not explain why everything seemed to
work OK with LyX 2.3.3 on Mint 18.3
On Mint 18.3 the system-wide installation of ImageMagick is:
ImageMagick 6.8.9-9 Q16 x86_64 2019-11-12
On Windows 10, the LyX2.3.4.3 installer comes bundled with a later version:
ImageMagick 7.0.9-19 Q16 x86 2020-01-26
which explicitly lists built-in support for gslib and ps, but ImageMagick 6 does not
list these among its "Delegates".
I would welcome advice on how to fix these problems.
Graeme
Confirmed here (same OS and LyX version). Turns out it's a security issue related to
ImageMagick. See this post
<https://cromwell-intl.com/open-source/pdf-not-authorized.html> for the gory
details. If you're willing to take the risk (I am), you can follow the suggestions in
the post, but there may be a quicker way. Wander over to /etc/Imagick-6 and list the
directory. You should see policy.xml and policy.xml.dpkg-old. They former is the
higher security/problematic policy file in force, and the .dpkg-old version is the
looser, less secure (but more LyX friendly) version. As root, give the new one a new
name or extension to keep it (or delete it if you will) and move or copy the
.dpkg-old version to policy.xml. Worked for me.
Paul
Thanks, Paul, for your quick and helpful reply.
Unfortunately, in my Mint etc/ImageMagick-6 folder there was only
policy.xml with no .dpkg-old version with which to compare or replace it.
I followed the link you supplied, had a look at the documentation for
ImageMagick, and at the policy.xml file bundled with LyX for Windows,
but the syntax and terminology of policy.xml files remains rather
obscure to me.
Since it's the effect of these security policies on the behaviour of
ImageMagick with EPS (and PS) files that matters. I've made small
changes to the ImageMagick-6 version that allow the convert command to
operate as desired on EPS and PDF files.
The key code fragment in /etc/ImageMagick-6/policy.xml is in the
<policymap> section of the file:
<!-- disable ghostscript format types -->
<policy domain="coder" rights="none" pattern="PS" />
<policy domain="coder" rights="none" pattern="PS2" />
<policy domain="coder" rights="none" pattern="PS3" />
<policy domain="coder" rights="none" pattern="EPS" />
<policy domain="coder" rights="none" pattern="PDF" />
<policy domain="coder" rights="none" pattern="XPS" />
I modified two lines in this fragment as follows:
<policy domain="coder" rights="read|write" pattern="PS" />
<policy domain="coder" rights="read|write" pattern="EPS" />
1. Changing only the PS line allowed the LyX editor window correctly to
display included graphic files in EPS or PDF format, but
File/Export/PDF(ps2pdf) still failed with LyX files that included PNG or
JPEG graphics.
2. Changing only the EPS line resolved the problem of exporting files
with included PNG or JPEG graphics, but did not allow the LyX editor
window to display included graphic files in EPS or PDF format.
3. It wasn't necessary to change the PDF line. Not sure why.
4. It seems that changing both the PS and the EPS lines is sufficient to
resolve both problems, but I don't know whether this is the necessary
minimum. Is there a better, or safer, way of modifying the file policy.xml?
Finally, I'm surprised that the problem has so far only been reported
for Linux Mint, prompting the following questions:
a) Does Mint have a much stricter security policy for ImageMagick than
Ubuntu or other Linux distributions?
b) None of the lines in the <policymap> fragment above appear in the
policy.xml for ImageMagick 7 that is bundled with LyX 2.3.4.3 in the
Windows installer. Was that policy.xml crafted specifically to work with
LyX, and to avoid the problems reported here?
Graeme
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