Hi,
The recent Wikidata JSON dumps again contain huge amounts of broken JSON
where empty maps are serialized as [] instead of using {}. Just grep for
"claims":[]
or
"aliases":[]
or
any other key that requires a map
to find many examples. The scope of the problem is massive. Basically
all entity documents that include some empty map are broken, which is
almost every entity document in
http://dumps.wikimedia.org/other/wikidata/20150803.json.gz. Concretely,
there are around 15.7 million entities with [] for aliases.
This is critically breaking the consumption of Wikidata content for all
model-based JSON parsers, including Wikidata Toolkit.
The bug used to occur only in XML dumps, but now also affects the JSON
dumps in the same way. In previous JSON dumps, the problem was avoided
by omitting empyt maps altogether (no keys, no values), which is better
because it allows implementations to fall back to the obvious default.
This is still done in the Web API, e.g.,
https://www.wikidata.org/wiki/Special:EntityData/Q12062430.json
It would be nice to test the export code before deploying it.
Regards,
Markus