Cycle detection doesn't catch cycles through collections

[cushon]

The cycle detection introduced in #632 / #645 doesn't handle cycles that involved collections. The following example still results in a StackOverflowError:

import java.util.Collections;
import java.util.List;
import org.json.JSONObject;

class Json {

  public static void main(String[] args) {
    new JSONObject(new Foo());
  }

  public static class Foo {

    public List<Foo> getFoos() {
      return Collections.singletonList(this);
    }
  }
}

Exception in thread "main" java.lang.StackOverflowError
	at org.json.JSONObject.getKeyNameFromMethod(JSONObject.java:1591)
	at org.json.JSONObject.populateMap(JSONObject.java:1548)
	at org.json.JSONObject.populateMap(JSONObject.java:1529)
	at org.json.JSONObject.<init>(JSONObject.java:366)
	at org.json.JSONObject.wrap(JSONObject.java:2499)
	at org.json.JSONObject.wrap(JSONObject.java:2457)
	at org.json.JSONArray.addAll(JSONArray.java:1609)
	at org.json.JSONArray.<init>(JSONArray.java:176)
	at org.json.JSONObject.wrap(JSONObject.java:2478)
	at org.json.JSONObject.populateMap(JSONObject.java:1563)
	at org.json.JSONObject.populateMap(JSONObject.java:1529)
	at org.json.JSONObject.<init>(JSONObject.java:366)

[stleary]

To be fixed

[johnjaylward]

@stleary this is a different issue than the one fixed in #651

[hendrixjoseph]

I have a fix for this (plus a unit test), as well as a couple other locations this might still be happening. I'll try to make a PR tomorrow.

Can you assign me please? Thank you.

[stleary]

I don't think it will be possible to check for cycles in collections without impacting performance. If you disagree, post here to reopen this ticket.