Fix infinite loop in sun.sun (#89723)

homeassistant/helpers/sun.py

@@ -82,7 +82,8 @@ def get_location_astral_event_next(
         kwargs["observer_elevation"] = elevation
 
     mod = -1
-    while True:
+    first_err = None
+    while mod < 367:
         try:
             next_dt = (
                 cast(_AstralSunEventCallable, getattr(location, event))(
@@ -94,9 +95,13 @@ def get_location_astral_event_next(
             )
             if next_dt > utc_point_in_time:
                 return next_dt
-        except ValueError:
-            pass
+        except ValueError as err:
+            if not first_err:
+                first_err = err
         mod += 1
+    raise ValueError(
+        f"Unable to find event after one year, initial ValueError: {first_err}"
+    ) from first_err
 
 
 @callback

tests/helpers/test_sun.py

@@ -3,6 +3,8 @@
 from datetime import datetime, timedelta
 from unittest.mock import patch
 
+import pytest
+
 from homeassistant.const import SUN_EVENT_SUNRISE, SUN_EVENT_SUNSET
 from homeassistant.core import HomeAssistant
 import homeassistant.helpers.sun as sun
@@ -192,3 +194,15 @@ def test_norway_in_june(hass: HomeAssistant) -> None:
     )
     assert sun.get_astral_event_date(hass, SUN_EVENT_SUNRISE, june) is None
     assert sun.get_astral_event_date(hass, SUN_EVENT_SUNSET, june) is None
+
+
+def test_impossible_elevation(hass: HomeAssistant) -> None:
+    """Test altitude where the sun can't set."""
+    hass.config.latitude = 69.6
+    hass.config.longitude = 18.8
+    hass.config.elevation = 10000000
+
+    june = datetime(2016, 6, 1, tzinfo=dt_util.UTC)
+
+    with pytest.raises(ValueError):
+        sun.get_astral_event_next(hass, SUN_EVENT_SUNRISE, june)