Fix suggested by Magnus Kessler: in class Page, it is possible for

self.parser to be None; in that case don't dereference it in
getnames().

Tools/webchecker/webchecker.py

@@ -681,7 +681,10 @@ class Page:
 
     # Method to retrieve names.
     def getnames(self):
-        return self.parser.names
+        if self.parser:
+            return self.parser.names
+        else:
+            return []
 
     def getlinkinfos(self):
         # File reading is done in __init__() routine.  Store parser in