Is it intentional that #partial_value calls on_load?

[mame]

Currently #partial_value sometimes calls on_load. Is this intentional?

If it is, the in_use lock has to cover #partial_value too: otherwise touching the parser from within on_load triggers a use-after-free.

require "json"
parser = nil
parser = JSON::ResumableParser.new(on_load: ->(o) {
  parser.parse if o.is_a?(Array) # re-entrant
  o
})
parser << "[1,"
parser.parse
parser.partial_value # AddressSanitizer: heap-use-after-free

The fix in this PR holds in_use for the duration of #partial_value, like #parse does.

Personally, #partial_value is interesting, but I am not sure it has a real use case.

[byroot]

Currently #partial_value sometimes calls on_load. Is this intentional?

It is yes.

[mame]

I was wondering what would happen if incomplete data were passed to create_additions via on_load, but it turns out ResumableParser doesn't support create_additions at all. I think that's fine then.

By the way, passing keyword arguments like create_additions: to ResumableParser.new silently ignores them, which might be a little confusing.

[byroot]

passing keyword arguments like create_additions: to ResumableParser.new silently ignores them, which might be a little confusing.

Yes, it's because like all of JSON, there is actually no keyword arguments, it's all option hashes.

I would like to transition to keyword arguments for all of JSON, but I think that's something for 3.0.

But perhaps Resumable should already use keyword arguments. I'll think about it.