[sr-dev] $var null confusion

[Juha Heinanen]

the fact that $var cannot hold value seems to be a constant cause of
confusion.  opensips version 1.9.0 has this:

  $var() script variables have now an explicit value of NULL, so values
  can be (a) integer, (b) string or (c) NULL. The NULL value can be tested
  in an "if" conditions

i don't know how it is implemented, but might be a good idea for
kamailio too.

-- juha