hpgl export crashes, file remains empty

[Jay]

When exporting a not-so-simple file as hpgl, the exporter crashes, leaving the following error report:

Traceback (most recent call last):

  File "hpgl_output.py", line 93, in <module>

    e.affect()

  File "C:\Program Files (x86)\Inkscape\share\extensions\inkex.py", line 215, in affect

    self.effect()

  File "hpgl_output.py", line 80, in effect

    cspsubdiv.cspsubdiv(p, self.options.flat)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 17, in cspsubdiv

    subdiv(sp,flat)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 38, in subdiv

    subdiv(sp,flat,i)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 38, in subdiv

    subdiv(sp,flat,i)

[...] (I have removed all the lines that are obviously part of the recursive loop and remain the same to make this report more readable)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 38, in subdiv

    subdiv(sp,flat,i)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 38, in subdiv

    subdiv(sp,flat,i)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 38, in subdiv

    subdiv(sp,flat,i)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 38, in subdiv

    subdiv(sp,flat,i)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 38, in subdiv

    subdiv(sp,flat,i)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 29, in subdiv

    subdiv(sp,flat,i+1)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 26, in subdiv

    m = maxdist(b)

  File "C:\Program Files (x86)\Inkscape\share\extensions\cspsubdiv.py", line 12, in maxdist

    return max(s1.distanceToPoint(p1),s1.distanceToPoint(p2))

  File "C:\Program Files (x86)\Inkscape\share\extensions\ffgeom.py", line 88, in distanceToPoint

    return self.perpDistanceToPoint(p)

  File "C:\Program Files (x86)\Inkscape\share\extensions\ffgeom.py", line 90, in perpDistanceToPoint

    len = self.length()

  File "C:\Program Files (x86)\Inkscape\share\extensions\ffgeom.py", line 97, in length

    return math.sqrt((self.delta_x() ** 2) + (self.delta_y() ** 2))

  File "C:\Program Files (x86)\Inkscape\share\extensions\ffgeom.py", line 66, in delta_x

    return self[1]['x'] - self[0]['x']

RuntimeError: maximum recursion depth exceeded

[Alvin Penner (apenner)]

confirmed at a flatness of 0.5
the problem apparently goes away at a flatness of 1. The flatness controls the precision of the fit, and low flatness will yield a larger, more precise, file.

[su_v (suv-lp)]

Same as Bug #487052 “HPGL Output crashes ”?

@Alvin - could it be that both HPGL reports are a duplicate of

Bug #340123 “Effects - Modify Path - Flatten Beziers fails on complicated paths with small flatness parameter”
<https://bugs.launchpad.net/inkscape/+bug/340123>

[Jay (jannis)]

Thanks for the information. File output with flatness of 1 totally sufficed, the output file is nice and fine.

Sorry for the duplicate though.

[Alvin Penner (apenner)]

@~suv - yes, I think you are correct, these bugs all look the same. It would be nice to fix this one. It is clear that the flatness causes the problem, but it is not clear how to predict the crash ahead of time, before it happens.