fix: database error handling during import of a non-user item

The code to handle the case of retired and active users causing errors
during import can get called on other db errors as well (e.g. out of
memory in postgresql).

The code that trys to detect/repair the out of order user case hard
coded the db.user class. This crashed when a db error occurred when
loading another data object (e.g. msg). Fix the crash by using the
proper db object class for the object class being loaded.

Credit to Norbert Schlemmer for finding this.

Author: rouilj

CHANGES.txt

@@ -56,6 +56,9 @@ Fixed:
   Rouillard from issue on mailing list by Chuck Cunningham)
 - make roundup-server exit more quickly on ^C. This seems to be
   limited to windows. (John Rouillard)
+- Fix error handling so failure during import of a non-user item
+  doesn't cause a second traceback. (Found by Norbert Schlemmer, fix
+  John Rouillard)
 
 Features:
 

roundup/backends/rdbms_common.py

@@ -3298,11 +3298,12 @@ def import_list(self, propnames, proplist):
             logger.info('Attempting to handle import exception '
                         'for id %s: %s' % (newid, e))
 
-            keyname = self.db.user.getkey()
+            classdb = self.db.getclass(self.classname)
+            keyname = classdb.getkey()
             if has_node or not keyname:  # Not an integrity error
                 raise
             self.db.restore_connection_on_error()
-            activeid = self.db.user.lookup(d[keyname])
+            activeid = classdb.lookup(d[keyname])
             self.db.sql(retired_sql, (-1, activeid))  # clear the active node
             # this can only happen on an addnode, so retry
             try: