Prevent weather icon flicker

shell/plugins/panels/weather/Model.js

@@ -194,6 +194,12 @@ function currentIcon(current, fallback) {
   return fallback || ""
 }
 
+// wttr.in has no day/night flag. Use its icon only to fill an empty initial
+// state, never to replace a day/night-aware icon resolved by Open-Meteo.
+function provisionalCurrentIcon(current, resolvedIcon) {
+  return resolvedIcon || currentIcon(current, "")
+}
+
 function weatherResponseCompletesSave(hasConfiguredCoordinates, source) {
   return hasConfiguredCoordinates ? source === "open-meteo" : source === "wttr"
 }
@@ -290,6 +296,7 @@ if (typeof module !== "undefined") {
     openMeteoForecastDays: openMeteoForecastDays,
     openMeteoCurrentCondition: openMeteoCurrentCondition,
     currentIcon: currentIcon,
+    provisionalCurrentIcon: provisionalCurrentIcon,
     weatherResponseCompletesSave: weatherResponseCompletesSave,
     wttrNextForecastDays: wttrNextForecastDays,
     buildForecastDays: buildForecastDays,

shell/plugins/panels/weather/Panel.qml

@@ -315,7 +315,7 @@ Panel {
           var parsed = JSON.parse(raw)
           root.report = parsed
           if (!root.hasConfiguredCoordinates)
-            root.label = Model.currentIcon(parsed.current_condition && parsed.current_condition[0], root.label)
+            root.label = Model.provisionalCurrentIcon(parsed.current_condition && parsed.current_condition[0], root.label)
           root.forecastRetries = 0
           if (Model.weatherResponseCompletesSave(root.hasConfiguredCoordinates, "wttr"))
             root.finishSavingLocation()

test/shell.d/weather-test.sh

@@ -112,6 +112,8 @@ assert(weather.dayIcon({ openMeteoWeatherCode: 95 }).length > 0, 'weather maps O
 assertEqual(weather.currentIcon({ openMeteoWeatherCode: 0, isDay: 1 }, ''), weather.iconForOpenMeteoCode(0), 'weather uses the current Open-Meteo icon with current values')
 assertEqual(weather.currentIcon({ openMeteoWeatherCode: 0, isDay: 0 }, ''), weather.iconForCode(113, true), 'weather uses the nighttime Open-Meteo icon after sunset')
 assert(weather.iconForOpenMeteoCode(45, true) !== weather.iconForOpenMeteoCode(45, false), 'weather distinguishes nighttime fog from daytime fog')
+assertEqual(weather.provisionalCurrentIcon({ weatherCode: 113 }, ''), weather.iconForCode(113, false), 'weather uses wttr to fill an empty initial icon')
+assertEqual(weather.provisionalCurrentIcon({ weatherCode: 113 }, 'night'), 'night', 'weather refresh preserves a resolved day-night icon')
 assert(
   fs.readFileSync(root + '/shell/plugins/panels/weather/Panel.qml', 'utf8').includes('text: root.label || "—"'),
   'weather hero and bar use the same resolved icon'