Handle empty recording days and stale playback queries

test_app.py

@@ -1,6 +1,7 @@
 """Isolated regression tests: python -m unittest -v test_app."""
 import hashlib
 import http.client
+import io
 import json
 import os
 import tempfile
@@ -128,6 +129,18 @@ class WebTests(unittest.TestCase):
         self.assertIn('h264_vaapi', command)
         self.assertIn('pipe:1', command)
 
+    def test_empty_recording_day_is_not_service_failure(self):
+        error = app.urllib.error.HTTPError('http://localhost/list', 404, 'Not Found', {},
+                                           io.BytesIO(b'{"error":"no recording segments found"}'))
+        with patch('app.urllib.request.urlopen', side_effect=error):
+            self.assertEqual(app.media_json('/list?path=example', playback=True), [])
+
+    def test_real_media_service_error_is_preserved(self):
+        error = app.urllib.error.HTTPError('http://localhost/list', 500, 'Error', {}, io.BytesIO(b'{}'))
+        with patch('app.urllib.request.urlopen', side_effect=error):
+            with self.assertRaises(app.Problem):
+                app.media_json('/list?path=example', playback=True)
+
 
 if __name__ == '__main__':
     unittest.main()