# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1444340249 -7200
# Node ID 3be0716ebf8fcf2ac7b109921ea06f5249ab6a05
# Parent  1af9f6724ea2769235756245890737b76f2ffb7e
Handle hopeless cases of no appropriate colours by picking an arbitrary colour.

diff -r 1af9f6724ea2 -r 3be0716ebf8f optimiser.py
--- a/optimiser.py	Thu Oct 08 10:42:30 2015 +0200
+++ b/optimiser.py	Thu Oct 08 23:37:29 2015 +0200
@@ -20,7 +20,7 @@
 with this program.  If not, see <http://www.gnu.org/licenses/>.
 """
 
-from random import random
+from random import random, randrange
 from os.path import split, splitext
 import EXIF
 import PIL.Image
@@ -170,6 +170,9 @@
 
     l = pattern(rgb, chosen)
     limit = sum([f for f, c in l])
+    if not limit:
+        return l[randrange(0, len(l))][1]
+
     choose = random() * limit
     threshold = 0
     for f, c in l: