# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1488544873 -3600
# Node ID d1bf04436c7c078b676259f04fb291ca38daf931
# Parent  7c8a7ad8dc500f262d4deadaaa09e41ec7db8585
Produce valid empty allocation locations when allocating attributes/parameters.

diff -r 7c8a7ad8dc50 -r d1bf04436c7c optimiser.py
--- a/optimiser.py	Fri Mar 03 13:25:11 2017 +0100
+++ b/optimiser.py	Fri Mar 03 13:41:13 2017 +0100
@@ -1105,7 +1105,7 @@
             # Handle empty positions.
 
             if not attrnames:
-                allocated.append([])
+                allocated.append([None] * len(names))
                 continue
 
             base = None
@@ -1135,7 +1135,12 @@
                     raise OptimiseError, "Attribute %s cannot be explicitly positioned at %d." % \
                                          (attrname, len(allocated))
 
-            allocated.append(base)
+            # Handle empty positions.
+
+            if base:
+                allocated.append(base)
+            else:
+                allocated.append([None] * len(names))
 
     # Try to allocate each attribute name in turn.