<DB as ReadonlyStorage>::get treats empty values as missing keys

[reuvenpo]

The signature of the <DB as ReadonlyStorage>::get method suggests that the method distinguishes missing keys from keys with empty values, but as you can see on line 33, it returns None for empty keys. Looks like len=0 is returned for missing keys as well (which makes sense).

This is related to #55 .

[webmaster128]

I don't know if the storage backend can differentiate the two cases (zero/null handling in Go seems to be a big 🤯 and it does not get easier over FFI). But I think we should work towards supporting both cases. Then an application can choose to treat them as the same thing or not.

[reuvenpo]

This has been resolved in #67 . @webmaster128 @ethanfrey I think we can close this issue.

[webmaster128]

Nice. Can you add "Closes #56" to into the PR description, to get the linking right?

[reuvenpo]

Sure, Done :)