putIfAbsent returns wrong value

[GenghisChen]

Using the cache in its ConcurrentMap form (.asMap()), when time-limited entries expire the .get() method returns null as is should, but the .putIfAbsent() method return the old-expired value.

Consider the following example:

    Cache<Integer, String> cache1 = Caffeine.newBuilder()
            .expireAfterWrite(1, TimeUnit.SECONDS)
            .build();
    ConcurrentMap<Integer, String> cache2 = cache1.asMap();

    cache2.put(1, "A");
    Thread.sleep(2000);
    System.out.println(cache2.get(1));  // Expect to see null (and see null)
    System.out.println(cache2.putIfAbsent(1, "B")); // Expect to see null (and see "A")

[ben-manes]

You're right! A million unit test executions and somehow I missed checking for this.

Thanks for the test case. I'll fix and release an update this evening.

[ben-manes]

Released v1.3.2 to Maven Central.