Range skips zero in iterator.

[nodech]

DB Layout for key:

  e: bdb.key('e', ['uint32']),

Range Usage:

    return db.range({
      gte: layout.e.min(),
      lte: layout.e.max(),
      parse: key => layout.e.parse(key)
    });

If there's 0 written in that field, iterator.parse skips that value.
Issue comes from here: https://github.com/bcoin-org/bdb/blob/master/lib/db.js#L1162

We need some convention, what you need to return from parser to skip that value.

E.g. null or undefined.

It will probably skip zero string and other falsy values )))

@chjj

I can just return buffers and parse on my own. but still I think we need some convention when to skip in iterator.

[chjj]

I would say if (item != null) is the answer (not null or undefined). Will fix.

[nodech]

cool. I just didn't decide on convention or I would make PR.