if-then in allOf is not working when additionalProperties is set to false

[Stusu]

Prerequisites

• I have searched the existing issues
• I understand that providing a SSCCE example is tremendously useful to the maintainers.
• I have read the documentation
• Ideally, I'm providing a sample JSFiddle or a shared playground link demonstrating the issue.

What theme are you using?

core

Version

5.x

Current Behavior

Let's take an example: playground

The schema has "additionalProperties" set to false and "abc" enum property, then we have "allOf" section with 2 conditions for "abc", each of them should add some new, required property, but it is not rendering, unless "additionalProperties" is removed or set to true.
Even though they are not shown, the validation is executed against them and it fails.

Expected Behavior

The schema from above should add properties that are conditionally configured in "allOf" section even when "additionalProperties" is set to false, so they can be filled.

Steps To Reproduce

1. On this playground
2. Select "value1" or "value2" in "abc" field
3. Execute validation

Environment

- OS: Windows 10
- Browser: Chrome

Anything else?

No response

[heath-freenome]

@Stusu good bug! Is this issue blocking you? We have a skeleton crew here and could use some help fixing things

[Stusu]

It is not blocking me, as I was able to use "dependencies" instead of "if-then".
It is possible to make it work as expected by adding ignoreAdditionalProperties: true to mergeAllOf options in retrieveSchema, but the form slows down to unacceptable level.
I've counted 48x executions of retrieveSchema function for single change of "abc" field value. That's a lot.
I'm going to investigate it further in my free time.

[heath-freenome]

Thanks! Let us know if you have any questions