#1255 Polygon clipping

[Christoph Bersch]

Hi,

I found a bug in the new clipping code. I changed clip_polygon() to use a temporary internal array for the clipping computation. In the old code 'in' was misused for this purpose, which gave problems. The following examples failed with a memory error:

set xrange[-1:1]
set yrange[-1:1]

set object 1 polygon from first 0, first -1.1 \
  to first -1.1, first 0 \
  to first 0, first 1.1 \
  to first 1.1,first 0
set object 1 fc rgb 'red' fillstyle solid 1.0 border rgb 'black'

plot x

[Ethan Merritt]

Applied. Thanks.