From 2e1037005c4f107e67ced0876788cbe048707b0a Mon Sep 17 00:00:00 2001
From: Dermot Duffy <dermot.duffy@gmail.com>
Date: Mon, 17 May 2021 20:34:25 -0700
Subject: [PATCH] Allow camera stream to fail safely (#50728)

---
 homeassistant/components/camera/__init__.py |  9 +++++---
 tests/components/camera/test_init.py        | 23 ++++++++++++++++++++-
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/homeassistant/components/camera/__init__.py b/homeassistant/components/camera/__init__.py
index b52a36515d8..d9ccb0490c6 100644
--- a/homeassistant/components/camera/__init__.py
+++ b/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 @@ class Camera(Entity):
 
     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 @@ class CameraMjpegStream(CameraView):
         """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
diff --git a/tests/components/camera/test_init.py b/tests/components/camera/test_init.py
index 340a4b5d756..7c7890a3e5f 100644
--- a/tests/components/camera/test_init.py
+++ b/tests/components/camera/test_init.py
@@ -11,7 +11,12 @@ from homeassistant.components.camera.const import DOMAIN, PREF_PRELOAD_STREAM
 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