TestMDCAdapter::setContextMap‎ causes NullpointerException with TreeMap

[hoefi]

TestMDCAdapter::setContextMap‎ throws a NullpointerException when a TreeMap is used as a parameter.

I think it is caused by this line:
https://github.com/valfirst/slf4j-test/blob/139d72855228aabfe1d64f52ee42e0ddd061757b/src/main/java/com/github/valfirst/slf4jtest/TestMDCAdapter.java#L132C16-L132C16

containsKey with a null parameter is quite likely to cause an NullpointerException on a TreeMap (e.g. no specific comperator supporting null keys is set. See TreeMap::containsKey)

Source of that TreeMap could be TestMDCAdapter::getCopyOfContextMap.

UnitTest to validate:

@Test
    void setContextMapSetsCopy() {
        Map<String, String> newValues = new TreeMap<>();
        newValues.put(key, value);
        testMDCAdapter.setContextMap(newValues);
        Map<String, String> expected = new HashMap<>(newValues);
        newValues.clear();
        assertEquals(expected, testMDCAdapter.getCopyOfContextMap());
    }

[hoefi]

thank you for the quick response. 3.0.1 runs smoothly in our tests.