[maven-4.0.x] MonotonicClock.withZone() ignores zone parameter, violating Clock contract

[elharo]

MonotonicClock.withZone() ignores zone parameter, violating Clock contract

Found in: maven-4.0.x branch
File: api/maven-api-core/src/main/java/org/apache/maven/api/MonotonicClock.java (lines 147-150)
Severity: Low

Description

withZone() ignores the zone parameter and returns this, violating the java.time.Clock.withZone() contract:

@Override
public Clock withZone(ZoneId zone) {
    return this;    // ignores the zone parameter
}

The Clock.withZone() contract states: "Returns a copy of this clock with a different time-zone. The returned clock is functionally equivalent to this clock but with the specified time-zone." Ignoring the parameter and returning this means callers that pass a specific timezone expecting a clock in that zone will silently get UTC instead, leading to subtle timezone bugs.

[elharo]

This one is by design. However possibly this should throw an UnsuopportedOperationException instead? I'm not sure. It's also not obvious to me why this method can't be implemented by returning a different clock in a different timezone. Instants don't have timezones and returning a nw clock or even changing the zone of this clock does not compromise monotonicity as far as I can see.