fix(worldclock): name offset-set zones by their real offset everywhere

The Etc/GMT-n naming fix only covered the local row. A home that
follows a device set by UTC offset still put "GMT-9" under a UTC+9
face. The rule now lives in the one place every row and the face take
their city from.

app/src/main/java/de/jeanlucmakiola/clockula/ui/worldclock/WorldClockRowState.kt

@@ -1,6 +1,7 @@
 package de.jeanlucmakiola.clockula.ui.worldclock
 
 import de.jeanlucmakiola.clockula.domain.WorldClock
+import de.jeanlucmakiola.clockula.domain.Zones
 import de.jeanlucmakiola.clockula.domain.isKnownZone
 import de.jeanlucmakiola.clockula.domain.worldclock.DayLabel
 import de.jeanlucmakiola.clockula.domain.worldclock.DayNight
@@ -88,7 +89,7 @@ internal object WorldClockRows {
         WorldClockRowState(
             id = clock.id,
             zoneId = clock.zoneId,
-            name = clock.label ?: cityOf(clock.zoneId, entries),
+            name = clock.label ?: cityOf(clock.zoneId, entries, now),
             time = comparison?.localDateTime?.toLocalTime()?.truncatedTo(ChronoUnit.MINUTES),
             offset = comparison?.let { ZoneOffsetFormat.labelFor(it.offsetMinutes) },
             day = comparison?.let { ZoneOffsetFormat.dayLabelFor(it.dayDifference) },
@@ -101,10 +102,6 @@ internal object WorldClockRows {
      * The automatic local clock's row for [deviceZone], read against home like
      * any other row. Its [WorldClockRowState.id] is [LOCAL_ROW_ID], which no
      * stored row can have.
-     *
-     * A device set by UTC offset rather than by city (Android 13+ offers it)
-     * reports an id like `Etc/GMT-9`, whose last segment is no city and has
-     * its sign reversed, so such a row is named by its offset ("GMT+9").
      */
     fun local(
         deviceZone: ZoneId,
@@ -112,20 +109,13 @@ internal object WorldClockRows {
         now: Instant,
         entries: Map<String, ZoneEntry>,
         zoneNames: Map<String, String?>,
-    ): WorldClockRowState {
-        val name = if (ZoneCatalog.hasPlaceName(deviceZone.id)) {
-            null
-        } else {
-            ZoneOffsetFormat.gmtLabel(ZoneComparisons.utcOffsetMinutes(deviceZone, now))
-        }
-        return from(
-            clocks = listOf(WorldClock(id = LOCAL_ROW_ID, zoneId = deviceZone.id, label = name, sortOrder = 0)),
-            homeZone = homeZone,
-            now = now,
-            entries = entries,
-            zoneNames = zoneNames,
-        ).single()
-    }
+    ): WorldClockRowState = from(
+        clocks = listOf(WorldClock(id = LOCAL_ROW_ID, zoneId = deviceZone.id, label = null, sortOrder = 0)),
+        homeZone = homeZone,
+        now = now,
+        entries = entries,
+        zoneNames = zoneNames,
+    ).single()
 
     /** Room ids start at 1, so a row with this id is never a stored one. */
     const val LOCAL_ROW_ID: Long = -1L
@@ -143,13 +133,22 @@ internal object WorldClockRows {
         val local = now.toJavaInstant().atZone(homeZone).toLocalTime().truncatedTo(ChronoUnit.SECONDS)
         return HomeFaceState(
             zoneId = homeZone.id,
-            city = cityOf(homeZone.id, entries),
+            city = cityOf(homeZone.id, entries, now),
             zoneName = zoneNames[homeZone.id],
             time = local,
             dayFraction = DayNight.fractionAt(local),
         )
     }
 
-    private fun cityOf(zoneId: String, entries: Map<String, ZoneEntry>): String =
-        entries[zoneId]?.city ?: ZoneCatalog.cityFallbackFor(zoneId)
+    /**
+     * A device set by UTC offset rather than by city (Android 13+ offers it)
+     * reports an id like `Etc/GMT-9`, whose last segment is no place and has
+     * its sign reversed, so such a zone is named by its real offset ("GMT+9").
+     */
+    private fun cityOf(zoneId: String, entries: Map<String, ZoneEntry>, now: Instant): String =
+        if (!ZoneCatalog.hasPlaceName(zoneId) && Zones.isValid(zoneId)) {
+            ZoneOffsetFormat.gmtLabel(ZoneComparisons.utcOffsetMinutes(ZoneId.of(zoneId), now))
+        } else {
+            entries[zoneId]?.city ?: ZoneCatalog.cityFallbackFor(zoneId)
+        }
 }

app/src/test/java/de/jeanlucmakiola/clockula/ui/worldclock/WorldClockRowsTest.kt

@@ -265,4 +265,11 @@ class WorldClockRowsTest {
         assertThat(local.name).isEqualTo("GMT+9")
         assertThat(local.offset).isEqualTo(OffsetLabel.Ahead(8, 0))
     }
+
+    @Test
+    fun `a home that follows a device set by UTC offset is named by its real offset`() {
+        val home = WorldClockRows.home(ZoneId.of("Etc/GMT-9"), T0, entries, emptyMap())
+
+        assertThat(home.city).isEqualTo("GMT+9")
+    }
 }

docs/ARCHITECTURE.md

@@ -2406,8 +2406,8 @@ that city already shows the local time. Home that follows the device can never
 differ from it, so with no stored home the rule is always null, and Settings ›
 Clock says so under the switch rather than hiding it. A device set by UTC
 offset rather than by city reports an id like `Etc/GMT-9`, whose last segment
-has its sign reversed, so that row is named by its real offset ("GMT+9")
-instead (`ZoneCatalog.hasPlaceName`).
+has its sign reversed, so that zone is named by its real offset ("GMT+9")
+instead, on the local row and on the face alike (`ZoneCatalog.hasPlaceName`).
 
 The row is not stored. It is `WorldClockUiState.Loaded.local`, built per tick
 by the source from the same `zones.current()` read the face uses, so a