encoding/jsonschema: #/properties $ref results in bad reference

[rogpeppe]

What version of CUE are you using (cue version)?

73d4e255

Does this issue reproduce with the latest stable release?

Yes (v0.10.0)

What did you do?

exec cue import jsonschema: schema.json
exec cat schema.cue
exec cue vet schema.cue
-- schema.json --
{
    "$schema": "http://json-schema.org/draft-07/schema#",
    "type": "object",
    "properties": {
    	"foo": {
    		"type": "boolean"
    	}
    },
    "definitions": {
    	"bar": {
    		"$ref": "#/properties/foo"
    	}
    }
}

What did you expect to see?

Passing test.

What did you see instead?

> exec cue import jsonschema: schema.json
> exec cat schema.cue
[stdout]
@jsonschema(schema="http://json-schema.org/draft-07/schema#")
"foo"?: bool

#bar: foo
...
> exec cue vet schema.cue
[stderr]
#bar: reference "foo" not found:
    ./schema.cue:4:7
[exit status 1]
FAIL: /tmp/x.txtar:3: unexpected command failure

There are a couple of issues here: firstly the foo field name is quoted so can't be referred to.
Secondly, the foo field is optional so can't be referred to anyway.