crossref: handle MD source, catch exception

Author: Gerit Wagner

colrev/packages/crossref/src/crossref_search_source.py

@@ -68,9 +68,13 @@ def __init__(
         self.crossref_lock = Lock()
         self.language_service = colrev.env.language_service.LanguageService()
 
-        self.api = crossref_api.CrossrefAPI(
-            url=self.search_source.search_parameters["url"]
-        )
+        url = ""
+        if self.search_source.search_type == SearchType.MD:
+            url = self._api_url
+        else:
+            self.search_source.search_parameters["url"]
+
+        self.api = crossref_api.CrossrefAPI(url=url)
 
     def _validate_source(self) -> None:
         # validate version and migrate if needed

colrev/packages/get_year_from_vol_iss_jour/src/year_vol_iss_prep.py

@@ -211,7 +211,10 @@ def _get_year_from_crossref(self, *, record: colrev.record.record.Record) -> Non
                     source="CROSSREF(average)",
                     note="",
                 )
-        except requests.exceptions.RequestException:
+        except (
+            requests.exceptions.RequestException,
+            colrev_exceptions.NotEnoughDataToIdentifyException,
+        ):
             pass
 
     # pylint: disable=unused-argument