Allow camera stream to fail safely (#50728)

homeassistant/components/camera/__init__.py

@@ -160,7 +160,7 @@ async def async_get_stream_source(hass: HomeAssistant, entity_id: str) -> str |
 @bind_hass
 async def async_get_mjpeg_stream(
     hass: HomeAssistant, request: web.Request, entity_id: str
-) -> web.StreamResponse:
+) -> web.StreamResponse | None:
     """Fetch an mjpeg stream from a camera entity."""
     camera = _get_camera_from_entity_id(hass, entity_id)
 
@@ -399,7 +399,7 @@ async def handle_async_still_stream(
 
     async def handle_async_mjpeg_stream(
         self, request: web.Request
-    ) -> web.StreamResponse:
+    ) -> web.StreamResponse | None:
         """Serve an HTTP MJPEG stream from the camera.
 
         This method can be overridden by camera platforms to proxy
@@ -543,7 +543,10 @@ async def handle(self, request: web.Request, camera: Camera) -> web.StreamRespon
         """Serve camera stream, possibly with interval."""
         interval_str = request.query.get("interval")
         if interval_str is None:
-            return await camera.handle_async_mjpeg_stream(request)
+            stream = await camera.handle_async_mjpeg_stream(request)
+            if stream is None:
+                raise web.HTTPBadGateway()
+            return stream
 
         try:
             # Compose camera stream from stills

tests/components/camera/test_init.py

@@ -11,7 +11,12 @@
 from homeassistant.components.camera.prefs import CameraEntityPreferences
 from homeassistant.components.websocket_api.const import TYPE_RESULT
 from homeassistant.config import async_process_ha_core_config
-from homeassistant.const import ATTR_ENTITY_ID, EVENT_HOMEASSISTANT_START
+from homeassistant.const import (
+    ATTR_ENTITY_ID,
+    EVENT_HOMEASSISTANT_START,
+    HTTP_BAD_GATEWAY,
+    HTTP_OK,
+)
 from homeassistant.exceptions import HomeAssistantError
 from homeassistant.setup import async_setup_component
 
@@ -354,3 +359,19 @@ async def test_record_service(hass, mock_camera, mock_stream):
         # So long as we call stream.record, the rest should be covered
         # by those tests.
         assert mock_record.called
+
+
+async def test_camera_proxy_stream(hass, mock_camera, hass_client):
+    """Test record service."""
+
+    client = await hass_client()
+
+    response = await client.get("/api/camera_proxy_stream/camera.demo_camera")
+    assert response.status == HTTP_OK
+
+    with patch(
+        "homeassistant.components.demo.camera.DemoCamera.handle_async_mjpeg_stream",
+        return_value=None,
+    ):
+        response = await client.get("/api/camera_proxy_stream/camera.demo_camera")
+        assert response.status == HTTP_BAD_GATEWAY