octave w/ gnuplot backend produces bad pdf

[Dmitri A. S. <das...@gm...>]

The following octave scrip produces a bad pdf
(similar to one in  https://bugzilla.redhat.com/show_bug.cgi?id=1340660 )

graphics_toolkit ("gnuplot")
x=linspace(-1,1,11);
y=0;
z=x;
mesh(x,y,z);
colormap([0,0,0]);
print("bad_pdf.pdf", "-dpdfcairo")

====

A gnuplot script tat demonstrates the problem is attached (it contains
binary data).

Both firefox and chrome would render pdf anyway, but evince/xpdf/okular
would not.

I suspect the problem with octave's
colormap([0,0,0])
command here.
But I also think that gnuplot should not produce bad pdf.

Dmitri.
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