Hershey Text causes Inkscape Trunk to crash

[GoogleCodeExporter]

1. Run the latest bleeding edge Inkscape from 
https://launchpad.net/~inkscape.dev/+archive/trunk
2. Install the Hershey Text plugin by unpacking to 
~/.config/inkscape/extensions/
3. Click on Extensions>Render>Hershey Text

Popup reports "Inkscape has encountered an internal error and will close now". 
Program disappears, and console reports...
"Segmentation fault (core dumped)"

Note, this works even from a blank document, so seems a fairly clean and 
reproducable error. 

This is no issue unless it reflects a long-term change in Inkscape which 
renders Hershey Text permanently broken. If it's a temporary glitch in Inkscape 
trunk then obviously nothing needs to be done. However, the trunk build is 
otherwise stable and usable from recent experiments.

I'm running on Lubuntu 13.04 Beta 2

Original issue reported on code.google.com by c...@cefn.com on 21 Apr 2013 at 1:10

[GoogleCodeExporter]

The current development version of Inkscape has a significant number of crash 
issues, including reported crashes when trying to do such outlandish things as 
print, use the "live preview" feature in extensions, or open the Inkscape 
Preferences dialog.  Generally, these things are fixed for stable releases.

Please re-open this issue:
 - If the issue persists in a released version of Inkscape,
 - A change that can be made to Hershey Text that will fix the crash issue (but not break it on released versions of Inkscape)
 - If you can identify other extensions-- ones officially supported by Inkscape --that crash in the same way.  We could help file and/or corroborate a bug report.  As Hershey Text is not officially supported by the Inkscape team, reporting a bug on it to them will not help to fix the underlying issue.

Original comment by windell@oskay.net on 21 Apr 2013 at 4:20

• Changed state: Invalid
• Added labels: wait-and-see
• Removed labels: Priority-Medium, Type-Defect

[GoogleCodeExporter]

Hi, again.

Rolled back to a released Inkscape (pretty sure) which reports itself as...
cefn@cefn-raring-dell:~$ inkscape --version
Inkscape 0.48.4 r9939 (Feb 27 2013)
...in other words within Lubuntu's Synaptic package manager, I deselected 
inkscape-trunk and reselected inkscape to try and get back to stable. 

I also removed my .config/inkscape folder so there wasn't cruft from the newer 
version.

I now have exactly the same issue as originally reported, running the Hershey 
Text plugins within .config/inkscape/extensions from the 1.00 zip. 

Is there something I can do to gather meaningful data from the crash?

Original comment by c...@cefn.com on 21 Apr 2013 at 5:47

[GoogleCodeExporter]

We have been testing against Ubuntu, and the current Inkscape version that is 
supported on Ubuntu is 0.48.3.  I cannot reproduce the problem in 0.48.3 in 
Ubuntu.

The latest version of Inkscape supported on the Mac is 0.48.2, where Hershey 
Text also works properly.

Inkscape 0.48.4 is supported on Windows, and the Hershey Text extension also 
works there.

Original comment by windell@oskay.net on 23 Apr 2013 at 12:01

[GoogleCodeExporter]

Thanks for all the bug bisection. I hope to get somewhere with this as 
laser-cutting text is really important use of Inkscape for me.

Yeah, I'm basing my desktop on a pre-release image, but which will be the 
released version in two days, so 0.48.4 is coming through as the supported 
Ubuntu version I think.

Do you know is there any other residual material I might need to remove to roll 
back fully to 0.48.4. I've tried a purge and reinstall, with removal of the 
.config/inkscape directory, but perhaps there's something else.

Is there some weird way that the build could actually rely on Unity or some 
other undeclared dependency which happens to come with a full Ubuntu 
desktop!!?! I'm running Lubuntu - the minimal desktop based on LXDE

I'll have to have a go at a rollback to the quantal version of Inkscape from 
raring if nothing else works.

Original comment by c...@cefn.com on 23 Apr 2013 at 8:12

[GoogleCodeExporter]

Once it's easy for me to test on a copy of Ubuntu here, I'll certainly take a 
look.  I don't have a copy of lubuntu at present.  

Have you been able to see any similar problems with any other extensions?

Original comment by windell@oskay.net on 23 Apr 2013 at 8:17

[GoogleCodeExporter]

Nothing else has hit me, yet.

Original comment by c...@cefn.com on 23 Apr 2013 at 8:20

[GoogleCodeExporter]

I have the same issue with 0.48.3.1 r9886 based on the quantal-updates 
repository - identical behaviour. 

Should I somehow be running the plugin from a different source file? I 
downloaded the Hershey plugin in its separate zip before unzipping to 
.config/inkscape/extensions/ 

The folder structure looks like...

cefn@cefn-raring-dell:~/.config/inkscape/extensions$ ls -la
total 424
drwxr-x--x 2 cefn cefn   4096 Apr 23 09:30 .
drwxr-x--x 7 cefn cefn   4096 Apr 23 09:28 ..
-rwxr-xr-x 1 cefn cefn 413976 Apr 23 09:30 hersheydata.py
-rw-r--r-- 1 cefn cefn   3196 Apr 23 09:30 hershey.inx
-rwxr-xr-x 1 cefn cefn   3519 Apr 23 09:30 hershey.py

If you've an idea how I can see the nature of the error I'm happy to spend more 
time on it.

Original comment by c...@cefn.com on 23 Apr 2013 at 8:33

[GoogleCodeExporter]

I don't recognize any red flags with your setup, but I did not have any issues 
with 0.48.3 in my local tests. 

See if Extensions > Color > Black and White  causes any issues for you.  Also, 
try Extensions > Render > Gear.

Original comment by windell@oskay.net on 23 Apr 2013 at 8:58

• Changed state: New

[GoogleCodeExporter]

Both of those extensions are fine on 0.48.4 in my build. Gear produces a gear. 
If I select the gear fill it red and run Color > Black and White, it goes black 
as expected.

Original comment by c...@cefn.com on 23 Apr 2013 at 9:22

[GoogleCodeExporter]

Well, that rules out a couple of possible specific bugs...

Original comment by windell@oskay.net on 23 Apr 2013 at 7:04

[GoogleCodeExporter]

I'm having the same issue in Inkscape 0.48.4 r9939, the version offered in 
Ubuntu 13.04.  The "Inkscape has encountered an internal error and will close 
now" appears, and the terminal output looks as follows:

    terminate called after throwing an instance of 'std::logic_error'
      what():  basic_string::_S_construct null not valid

    Emergency save activated!
    Emergency save completed. Inkscape will close now.
    If you can reproduce this crash, please file a bug at www.inkscape.org
    with a detailed description of the steps leading to the crash, so we can fix it.
    Aborted (core dumped)

Original comment by bhs2...@gmail.com on 10 May 2013 at 2:55

[GoogleCodeExporter]

I actually just found a "fix". Remove the following element from hershey.inx:

    <_param name="emptyspace" type="description" xml:space="preserve">
    </_param>

Inkscape apparently doesn't like empty _param elements, even though it's valid 
XML.

Original comment by bhs2...@gmail.com on 10 May 2013 at 3:12

[GoogleCodeExporter]

Fixed in SVN.

Original comment by windell@oskay.net on 11 Aug 2013 at 7:24

• Changed state: Fixed
• Removed labels: wait-and-see

[GoogleCodeExporter]

Fixed in release 2.3.4.

Original comment by windell@oskay.net on 24 Nov 2013 at 2:01

[GoogleCodeExporter]

It's still broken in the version distributed here:

http://code.google.com/p/eggbotcode/downloads/detail?name=HersheyText_1.00.zip&c
an=3&q=hershey

Is there a better repository that everyone should be looking at?

However, I can confirm that removing the offending empty element fixed the 
problem for me (Kubuntu v13.01 with Inkscape 0.48.4 r9939).

Original comment by SteveBak...@gmail.com on 2 May 2014 at 12:38

[GoogleCodeExporter]

Please use release 2.3.4: 
https://code.google.com/p/eggbotcode/downloads/detail?name=eggbot_2013_08_11_2.3
.4.zip

Original comment by windell@oskay.net on 2 May 2014 at 12:49