message: Fix select return behavior (match C++)
diff: @@ -145,7 +145,9 @@ def _var_promote_select(a0, a1, a2):
  vt0 = _var_type(a0)
  vt1 = _var_type(a1)
  vt2 = _var_type(a2)
  - diff = getattr(a1, 'IsDiff', False) | getattr(a2, 'IsDiff', False)
  + diff = getattr(a0, 'IsDiff', False) | \
  + getattr(a1, 'IsDiff', False) | \
  + getattr(a2, 'IsDiff', False)
  if vt1 != vt2:
  vt1 = _var_type(a1, vt2)
  