// FIR_IDENTICAL
/*
 * KOTLIN DIAGNOSTICS SPEC TEST (NEGATIVE)
 *
 * SPEC VERSION: 0.1-313
 * PRIMARY LINKS: expressions, when-expression -> paragraph 5 -> sentence 1
 * expressions, when-expression, exhaustive-when-expressions -> paragraph 2 -> sentence 3
 * expressions, when-expression, exhaustive-when-expressions -> paragraph 2 -> sentence 4
 * expressions, when-expression, exhaustive-when-expressions -> paragraph 2 -> sentence 10
 */

// See also: KT-3743
fun foo(arg: Boolean?): String {
    // Must be exhaustive
    return when(arg) {
        true -> "truth"
        false -> "falsehood"
        null -> "unknown"
    }
}