[ferret_users] white contour and PostScript error

[Ryo Furue <furue@xxxxxxxxxx>]

Hi Ferreters,

We sometimes see an error like this

  ERROR: /typecheck in --aload--
  Operand stack:
  . . . . . . .

for a PostScript file generated with gksm2ps from a Ferret metafile,
when we use white contours.

I've identified part of the cause.  In the PostScript file, the
white contours are assigned color 0, which isn't defined in the
color table "ct".  So, when color 0 is used, as in

  0 o

error occurs.  ("o" is a function that changes the color, it seems.)

A workaround is to edit the PostScript file and manually define
color 0, as

  ct 0 [1.000000 1.000000 1.000000] put

Since I don't know the metafile "language", I don't know whether this
problem is due to the conversion by gksm2ps or it is already there in
the metafile.

Hope this helps,
Ryo