# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1441750045 -7200
# Node ID c1d09a02aa21e241e6e14d4f1bed05cb03656cdd
# Parent  cf2a36920a982996ec745c3ee8c7da01c75826fd
Handle lines with fewer than four base colours properly.

diff -r cf2a36920a98 -r c1d09a02aa21 optimiser.py
--- a/optimiser.py	Tue Sep 08 23:58:43 2015 +0200
+++ b/optimiser.py	Wed Sep 09 00:07:25 2015 +0200
@@ -97,7 +97,8 @@
         best_bases = None
         best_missing = None
         best_map = None
-        for bases in combinations(bu, 4):
+
+        for bases in combinations(bu, min(len(bu), 4)):
             bases = dict([(base, bu[base]) for base in bases])
             count = 0
             missing = []
@@ -114,6 +115,7 @@
                 best_missing = missing
                 best_map = tone_map
                 best = count
+
         chosen.append((best, best_bases or bases, best_map or tone_map, best_missing or missing))
 
     output = []