FULL PRODUCT VERSION :
java version "1.8.0_121"
Java(TM) SE Runtime Environment (build 1.8.0_121-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.121-b13, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Darwin localhost 16.4.0 Darwin Kernel Version 16.4.0: Thu Dec 22 22:53:21 PST 2016; root:xnu-3789.41.3~3/RELEASE_X86_64 x86_64 i386 MacBookPro11,4 Darwin

A DESCRIPTION OF THE PROBLEM :
IdentityHashMap's documentation says the map uses identity-based comparison for keys and values. Indeed, #keySet and #values() return identity-based collections. #entrySet returns collection that compares entries by key and value identity too.

However, the #remove(K,V) and #replace(K,V,V) methods inherited from Map (implemented with default methods in Map interface), compare values by equality rather than identity.

This can be shown with the code:

-------------
IdentityHashMap map = new IdentityHashMap();
map.put("key", new String("value"));
System.out.println(map.remove("key", new String("value"))); // expected "false"
-------------

REGRESSION. Last worked in version 7u80

ADDITIONAL REGRESSION INFORMATION:
In Java 7 there was no public method in IdentityHashMap that compared values by equality.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
IdentityHashMap map = new IdentityHashMap();
map.put("key", new String("value"));
System.out.println(map.remove("key", new String("value")));

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
"false" should be printed, map unchanged
ACTUAL -
"true" printed, map emptied

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.util.IdentityHashMap;
public class A {
    public static void main(String[] args) {
        IdentityHashMap map = new IdentityHashMap();
        map.put("key", new String("value"));
        System.out.println(map.remove("key", new String("value")));
    }
}
---------- END SOURCE ----------