Backup does not correctly escape CDATA sections in issue description

Consider the following (and realize that I have not put complete CDATA syntax anywhere in this text, as that might cause the same issue for you lot as we have):

<Issue ...>
<description>CDATA sometext

<error>
CDATA{ Foo ENDCDATA
</error>
ENDCDATA
</description>
</Issue>

What happened was a QA tester logged a bug with the malformed CDATA section in issues description, that is, they typed CDATA{ - note curly brace was used instead of square [ - so the opening CDATA was ignored, but two closes found

This results in the CDATA section JIRA wrapped around the <description> element in being terminated early, and then the closing </error> element being parsed, causing an XML malformed error ("description" must be terminated by the etc.. etc.)

Fixing the CDATA section in bug fixes the XML insofar as validation goes, however JIRA still won't import until the CDATA section is removed from the description field all together. Removing the CDATA from the description completely, via SQL, got rid of the problem.

This is fairly serious/sneaky because you don't know this has happened to your exports until you try to restore from them..