[Rd] contour method="edge" when vertical. (PR#7178)

[jjanmaat at acadiau.ca]

Full_Name: John Janmaat
Version: 9.0
OS: SuSE Linux 9.0
Submission from: (NULL) (137.224.252.10)


When plotting a contour map, with multiple maps on a page, and overlaying
contour plots, and sending output to a postscript file, plotting will halt with
'method="edge"' for contours that appear to be nearly vertical.  Unfortunately I
cannot reproduce the problem using a simple code snippet, but will send code and
datafile that are creating problem to anyone interested.

John.