PDF, Word and XML exports fail with absolute temp directory path in confluence.cfg.xml

Confluence cannot resolve the file path of the 'temp' directory in the home folder properly if it is modified in the confluence.cfg.xml.
This leads to a 403 - Forbidden - page in Confluence when attempting a PDF Export.

E.g. Default value:
<property name="webwork.multipart.saveDir">${confluenceHome}/temp</property>

Changed value:
<property name="webwork.multipart.saveDir">/home/foo/confluence-temp/test</property>

The result is this URL and 403 page shown:

http://localhost:8080/download//home/foo/confluence-temp/test/export_06192007_133711/ds-32787-20070619-13_37_11.pdf

Checking the proper path with HttpLiveHeaders, the correct path should be something like this:

http://localhost:8080/download/temp/export_06192007_133711/ds-32787-20070619-13_37_11.pdf

Confluence should be able to update the path with this change. Consequently, it can be fixed by reverting the above webwork.multipart.saveDir back to ${confluenceHome}/temp.

This issue can be reproduced by using the symbolic link as well.

Workaround solution:
On Linux, you can use the file system bind via "fstab" to bind the temp folder with another temp folder from another file system.