'Zero' bug. An empty infon doesn't work as index

[Bruce Long]

I don't remember how to re-create this, but I am sure it will pop up again.

[Bruce Long (qstream)]

('1', 'test #1 of repeated indexing (i.e., filtering)', "{%{111, '222', {}, {'a', 'b', 'c'}}*2+[...]|...}", '<{"222" {"a" "b" "c" } }>')

The '{}' (just after the '222') causes problems in the above test.

Also, {} doesn't work as an index.