Jira doesn't clean up $JIRA_INSTALL/temp

Summary

Jira doesn't seem to clean the temp directory. I have hundreds of files in jira/temp, named attachment-8344575760376439812.tmp etc.
This is a very major problem for our installation since we keep running out of space.

Expected Results

Jira deletes old files during startup

Actual Results

Looking at the file dates, many of the files are several months old.

Workaround

• It is safe to manually delete the contents of the JIRA INSTALL/temp directory, as long as Jira is not running. Jira uses this directory to store all sorts of temporary files (downloading add-ons, add-ons manually uploaded by users, CSV imports, etc), so deleting it while Jira is running could cause instability, data loss and system crash.