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kotlinlang

I've just come across this error. Is it a known issue?
```class A {
    override fun equals(other: Any?): Boolean {
        return true
    }
}
fun main() {
    val a = A()
    val b: A? = null
    println(a == b)  // It's always true, but IntelliJ warns it's always false
}```

that condition will always be false - its comparing an instance of `A` to `null`

at least from IntelliJ’s perspective, which is static code anlysis, not execution of the code.

No, it's `true` because of the overridden `equals`.

Note that if you change it to `a.equals(b)`, then it doesn't give that warning.
Also, `a.equals(null)` doesn't give a warning - which is correct, since `a == null` is not the same as `a.equals(null)` according to the <https://kotlinlang.org/spec/expressions.html#equality-expressions|language spec>, but this only applies for the literal `null`. If it's a value that happens to be null, then `a == b` is always the same as `a.equals(b)` and therefore IntelliJ shouldn't give that warning.

that `equals` does not satisfy the contract

<https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-any/equals.html>
&gt; Never equal to null: for any non-null value `x`, `x.equals(null)` should return false.

note that Java has the same wording, so this is true for non-Kotlin classes as well <https://docs.oracle.com/javase/8/docs/api/java/lang/Object.html#equals-java.lang.Object->

I have created a ticket to KTIJ project: <https://youtrack.jetbrains.com/issue/KTIJ-26980>

Thanks, Anton. Given what ephemient has pointed out, I can see why IntelliJ thinks the condition is always false (it assumes `equals` would satisfy the contract). It would be more important to see an inspection about `equals` not satisfying the contract, if that's possible. I made a comment on the ticket.