ifelse() bug?

gistfile1.txt

body common control { bundlesequence => { "example" }; }

bundle agent example {
vars:
 "foo[1]" string => "foo[1]";
 "foo[2]" string => "foo[2]";
 "foo[default]" string => "foo[default]";
 "randomvar" string => "foobar";

 secondpass::
  # additional tests
  "failtest1" string => ifelse("$(randomvar)_set","$(foo[1])","!$(randomvar)_set","$(foo[2])","$(foo[default])");
  "failtest2" string => ifelse("$(randomvar)_set","$(foo[1])","!$(randomvar)_set","$(nonexistent[var])","$(foo[default])");
  "failtest3" string => ifelse("!$(randomvar)_set","$(nonexistent[var])","$(foo[default])");

classes:
 "secondpass" expression => "any";
 "$(randomvar)_set" expression => "any";

reports:
 secondpass::
  "failtest1 result = \"$(failtest1)\" - should be foo[1]";
  "failtest2 result = \"$(failtest2)\" - should be foo[1]";
  "failtest3 result = \"$(failtest3)\" - should be foo[default]";
}