AndroidCompatTimeZoneRegistry logs inappropriate warning when constructing Europe/Copenhagen from Europe/Berlin

[rfc2822]

When an event has TZID:Europe/Copenhagen, AndroidCompatTimeZoneRegistry uses Europe/Berlin instead of Europe/Copenhagen (and displays a warning about this in the logs). Since both Europe/Berlin and Europe/Copenhagen are present in Android, this shouldn't happen.

The time zone has the same definition, so it's not a big problem, but it's still not working as intended.

[ArnyminerZ]

I've ran this test

@Test
fun getTimeZone_Existing_Copenhagen() {
    val tz = registry.getTimeZone("Europe/Copenhagen")
    assertEquals("Europe/Copenhagen", tz?.id)
    assertEquals("Europe/Copenhagen", tz?.vTimeZone?.timeZoneId?.value)
}

Is this correct? Am I misunderstanding anything?

[rfc2822]

Is this correct?

Yes.

I think the problem is primarily the logging. Your tests works, but it prints

08-03 03:05:52.235  5858  5877 W dCompatTimeZoneRegistry: Using Android TZID Europe/Copenhagen instead of ical4j Europe/Berlin

This warning (!) is highly irritating and I thought something was wrong when I saw it in some unrelated context.

If you have a look at the generated VTIMEZONE, the TZID is correct, but the body still contains references to Berlin:

@Test
    fun getTimeZone_Copenhagen() {
        val tz = registry.getTimeZone("Europe/Copenhagen")!!
        System.out.println(tz.vTimeZone)
        assertEquals(
            "Europe/Copenhagen",
            tz.id
        )
    }

// succeeds, prints

started: getTimeZone_Copenhagen(at.bitfire.ical4android.AndroidCompatTimeZoneRegistryTest)
Using Android TZID Europe/Copenhagen instead of ical4j Europe/Berlin
BEGIN:VTIMEZONE
LAST-MODIFIED:20240422T053450Z
TZURL:https://www.tzurl.org/zoneinfo/Europe/Berlin
X-LIC-LOCATION:Europe/Berlin
X-PROLEPTIC-TZNAME:LMT
TZID:Europe/Copenhagen
…
finished: getTimeZone_Copenhagen(at.bitfire.ical4android.AndroidCompatTimeZoneRegistryTest)

So it seems to work as expected, but

• the log message shouldn't be a warning, but at debug info level and have less alerting wording: "Using ical4j timezone ${tz.id} data to construct Android timezone $androidTzId" or something like that,
• Guess we could drop the TZURL etc. properties so that there's no reference to Berlin in the Copenhagen timezone. Although it's correct because it's an alias, it's confusing.