Problem

Attempting to export a Confluence Space in PDF or HTML may fail with EmptyStackException

Steps to Reproduce

1. Create an empty Confluence page
2. Set the below body in the bodycontent table for the page created at 1.

   <h3>Section</h3>
   <p>Some contnet.<br />
       <ac:emoticon ac:name="warning" /> Some more content
   </p>
   <p>placeholder...</p>
   <p>placeholder</p>
   <h3>placeholder</h3>
   <p>placeholder:
       <code>putKeyValue = function(key, value, <ac:link><ri:page ri:content-title="okCallback, errCallback" ri:space-key="TEST" /><ac:plain-text-link-body><![CDATA[okCallback, errCallback]]></ac:plain-text-link-body></ac:link>)</code>
   </p>
   <ac:parameter ac:name="title">placeholder</ac:parameter>
   <ac:parameter ac:name="language">javascript</ac:parameter><ac:plain-text-body>
       <![CDATA[kvs.putKeyValue("key", "value");
   ]]>
   </ac:plain-text-body>
   <h3>placeholder</h3>
   <p>placeholder</p>
   <p>placeholder
       <code>getKeyValue = function(key, dataCallback, <ac:link><ri:page ri:content-title="errCallback" ri:space-key="TEST" /><ac:plain-text-link-body><![CDATA[errCallback]]></ac:plain-text-link-body></ac:link>)</code>
   </p>
   <ac:parameter ac:name="title">placeholder</ac:parameter>
   <ac:parameter ac:name="language">javascript</ac:parameter><ac:plain-text-body>
       <![CDATA[// define the data callback
   var dataCallback = function(valuestring) {
       //work with valuestring
   };// get the value 
   kvs.getKeyValue("key", dataCallback);
   ]]>
   </ac:plain-text-body>  

3. Flush Confluence cache
4. Attempt the export the space where the page has been created either in PDF or HTML

Expected Results

Export succeeds.

Actual Results

The export fails and the following message is found in the logs:

YYYY-MM-DD 12:48:13,729 ERROR \[Long running task: PDF Space Export] \[core.task.longrunning.AbstractLongRunningTask] lambda$doRunInternal$0 Error during PDF export
 \-\- url: /wiki/spaces/flyingpdf/doflyingpdf.action \| referer: https://server/wiki/spaces/flyingpdf/flyingpdf.action?key=TEST \| traceId: 589d888753988fbd \| userName: test \| action: doflyingpdf
java.lang.RuntimeException: org.owasp.validator.html.ScanException: java.util.EmptyStackException
        at com.atlassian.confluence.content.render.xhtml.PolicyConfiguredCleaner.antiSamyClean(PolicyConfiguredCleaner.java:190\)

The above failure is caused by the following block in the storage format:

<ac:parameter ac:name="language">javascript</ac:parameter><ac:plain-text-body>
    <![CDATA[// define the data callback
var dataCallback = function(valuestring) {
    //work with valuestring
};// get the value 
kvs.getKeyValue("key", dataCallback);
]]>
</ac:plain-text-body>

as the antiSamyClean code is removing the content from the CDATA element and causes the EmptyStackException.

Workaround

Exclude the page from the export or change the problematic entry in the body content of the page from:

<ac:parameter ac:name="language">javascript</ac:parameter><ac:plain-text-body>
    <![CDATA[// define the data callback
var dataCallback = function(valuestring) {
    //work with valuestring
};// get the value 
kvs.getKeyValue("key", dataCallback);
]]>
</ac:plain-text-body>

to

<ac:parameter ac:name="language">javascript</ac:parameter><ac:plain-text-body>
 <code>
    <![CDATA[// define the data callback
var dataCallback = function(valuestring) {
    //work with valuestring
};// get the value 
kvs.getKeyValue("key", dataCallback);
]]>
 </code>
</ac:plain-text-body>