Do not round the sign symbol

flatlib/angle.py

@@ -58,7 +58,7 @@ def _fixSlist(slist):
 def _roundSlist(slist):
     """ Rounds a signed list over the last element and removes it. """
     slist[-1] = 60 if slist[-1] >= 30 else 0
-    for i in range(len(slist)-1, 0, -1):
+    for i in range(len(slist)-1, 1, -1):
         if slist[i] == 60:
             slist[i] = 0
             slist[i-1] += 1