deezerart: improve error handling

Do not crash if the response does not include a "data" object or is an error

plugins/deezerart/__init__.py

@@ -1,7 +1,7 @@
 PLUGIN_NAME = "Deezer cover art"
 PLUGIN_AUTHOR = "Fabio Forni <livingsilver94>"
 PLUGIN_DESCRIPTION = "Fetch cover arts from Deezer"
-PLUGIN_VERSION = '1.2'
+PLUGIN_VERSION = '1.2.1'
 PLUGIN_API_VERSIONS = ['2.5']
 PLUGIN_LICENSE = "GPL-3.0-or-later"
 PLUGIN_LICENSE_URL = "https://www.gnu.org/licenses/gpl-3.0.html"

plugins/deezerart/deezer/client.py

@@ -46,7 +46,15 @@ def handler(document: QByteArray, _: QNetworkReply, error: Optional[QNetworkRepl
             except json.JSONDecodeError:
                 callback([], error)
             else:
-                callback([obj.parse_json(dct) for dct in parsed_doc['data']], error)
+                result = []
+                error = None
+                if 'data' in parsed_doc:
+                    result = [obj.parse_json(dct) for dct in parsed_doc['data']]
+                elif 'error' in parsed_doc:
+                    error = parsed_doc['error'].get('message', 'Deezer responded with an unknown error')
+                else:
+                    error = 'Deezer returned an unexpected response'
+                callback(result, error)
 
         self._get(path,
                   queryargs={'q': str(options)},