[illusionoftalha]

Fixes #1096.

Both subset constructors dereference names.length in their constructor delegation, so a null names array fails before any fields can be selected. Treat null consistently with an empty names array: allocate an empty map and return without copying keys or reflecting over fields. Document that behaviour in both constructors.

Add regressions for null names with a populated JSONObject, null field names with a public-field object, and passing the null result of JSONObject.getNames on an empty object back to the subset constructor. The source JSONObject remains unchanged.

Validation on Windows / JDK 17:

• All three new tests fail with NullPointerException before the source fix.
• mvn test passes: 841 tests run, 0 failures/errors, 6 skipped.
• git diff --check passes.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[stleary]

@illusionoftalha Thanks for the PR, but it cannot be accepted at this time. Please see Requirements for Code Changes.