Merge pull request #2175 from rdswift/handle_missing_cdtoc_module

PICARD-2591: Accessing CD Lookup crashes Picard if there is no cdtoc module loaded

picard/tagger.py

@@ -134,7 +134,11 @@ from picard.util import (
     versions,
     webbrowser2,
 )
-from picard.util.cdrom import get_cdrom_drives
+from picard.util.cdrom import (
+    DISCID_NOT_LOADED_MESSAGE,
+    discid as _discid,
+    get_cdrom_drives,
+)
 from picard.util.checkupdate import UpdateCheckManager
 from picard.webservice import WebService
 from picard.webservice.api_helpers import (
@@ -573,6 +577,9 @@ class Tagger(QtWidgets.QApplication):
             log.error("Invalid LOOKUP command argument: '%s'", argstring)
 
     def handle_command_lookup_cd(self, argstring):
+        if not _discid:
+            log.error(DISCID_NOT_LOADED_MESSAGE)
+            return
         disc = Disc()
         devices = get_cdrom_drives()
 

picard/ui/mainwindow.py

@@ -99,6 +99,7 @@ from picard.util import (
     webbrowser2,
 )
 from picard.util.cdrom import (
+    DISCID_NOT_LOADED_MESSAGE,
     discid,
     get_cdrom_drives,
 )
@@ -913,7 +914,7 @@ class MainWindow(QtWidgets.QMainWindow, PreserveGeometry):
         self.cd_lookup_menu.clear()
         self.cd_lookup_action.setEnabled(discid is not None)
         if not drives:
-            log.warning("CDROM: No CD-ROM drives found - Lookup CD functionality disabled")
+            log.warning(DISCID_NOT_LOADED_MESSAGE)
         else:
             config = get_config()
             shortcut_drive = config.setting["cd_lookup_device"].split(",")[0] if len(drives) > 1 else ""

picard/util/cdrom.py

@@ -47,6 +47,7 @@ except ImportError:
     except (ImportError, OSError):
         discid = None
 
+DISCID_NOT_LOADED_MESSAGE = "CDROM: discid library not found - Lookup CD functionality disabled"
 
 DEFAULT_DRIVES = []
 if discid is not None: