Database inconsistency: quartz triggers referring to nonexistent filtersubscriptions, leads to JobExecutionException error in logs

The qrtz_triggers table contains a row for every subscribed-to filter subscription:

10410 | SUBSCRIPTION_10360 | SEND_SUBSCRIPTION | 10000 | 2005-08-01 00:55:42.887-05 | WAITING | SIMPLE | 2005-02-16 23:55:42.887-06 |
...

The numeric part of the second field ('10360') is a reference to the id of a filtersubscription row (see DefaultSubscriptionManager#getSubscription where this is called).

In many JIRA databases though, I have found quartz triggers referring to nonexistent filtersubscriptions, as shown by this query (here on jira.atlassian.com data):

atlassian-jira=# select TRIGGER_NAME FROM qrtz_triggers LEFT JOIN filtersubscription ON filtersubscription.id=SUBSTRING(TRIGGER_NAME, 14) WHERE filtersubscription.id IS NULL;
trigger_name
--------------------
SUBSCRIPTION_10340
SUBSCRIPTION_10170
SUBSCRIPTION_10280
SUBSCRIPTION_10050
SUBSCRIPTION_10060
SUBSCRIPTION_10040
SUBSCRIPTION_10410
SUBSCRIPTION_10400
SUBSCRIPTION_10080
SUBSCRIPTION_10380

When these quartz jobs run, the following error appears in the logs (from JIRA 3.2):

INFO: Job SEND_SUBSCRIPTION.SEND_SUBSCRIPTION threw a JobExecutionException:
org.quartz.JobExecutionException: Error retrieving schedule entry for this job. [See nested exception: java.lang.NullPointerException: ]
at com.atlassian.jira.issue.subscription.SendFilterJob.execute(SendFilterJob.java:27)
at org.quartz.core.JobRunShell.run(JobRunShell.java:191)
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:516)

• Nested Exception (Underlying Cause) ---------------
  java.lang.NullPointerException:
  at com.atlassian.jira.issue.subscription.DefaultSubscriptionManager.runSubscription(DefaultSubscriptionManager.java:140)
  at com.atlassian.jira.issue.subscription.SendFilterJob.execute(SendFilterJob.java:23)
  at org.quartz.core.JobRunShell.run(JobRunShell.java:191)
  at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:516)