[Bug] Comparison of additionalProperties should be fixed

[allenjzhang]

... when comparing additionalProperties: true vs additionalProperties: {}.

additionalProperties: true allows any additional properties of any type.
additionalProperties: {} is functionally equivalent to additionalProperties: true, allowing any additional properties without specific schema constraints.

Change between them should not be flagged.

[mikeharder]

@allenjzhang: What is the justification for treating these as equivalent? Can you link to a spec or something that these should be equivalent?

Why are we (or our code generators) switching from true to {}?

Would you say this is really a "bug", or more a "feature request"? Because true and {} are not equivalent in all contexts.

[mikekistler]

For additionalProperties, true and {} are equivalent. I would classify this as a bug fix though I suppose its arguable.

[mikeharder]

For additionalProperties, true and {} are equivalent. I would classify this as a bug fix though I suppose its arguable.

Do you have a source for this? Is this something universally true in OpenAPI, or specific to our flavor of OpenAPI?

[mikekistler]

https://datatracker.ietf.org/doc/html/draft-fge-json-schema-validation-00#section-5.4.4