Issue Summary

During indexing Confluence throws Unable to Parse subcalendars even if the page doesn't contain any calendars

Steps to Reproduce

1. Create a page and past below storage format.

   p><ac:structured-macro><ac:parameter ac:name="name"><ri:attachment ri:filename="Cross Channel Demo.mp4" /></ac:parameter></ac:structured-macro></p>
   

   When we add an attachment to the page, it looks like below

     <ac:structured-macro ac:macro-id="aea338db-2a95-4a06-a795-dfc7431f33ad" ac:name="view-file" ac:schema-version="1">
       <ac:parameter ac:name="name">
         <ri:attachment ri:filename="Cross channel Demo.mp4"/>
       </ac:parameter>
       <ac:parameter ac:name="height">250</ac:parameter>
     </ac:structured-macro>
   

   Please note the missing macro-id and ac-name

2. During indexing or reindexing Confluence throws following error which is misleading

   2021-04-17 13:35:23,515 WARN [Indexer: 21] [confluence.extra.calendar3.DefaultEmbeddedSubCalendarsParser] getEmbeddedSubCalendarIds Unable to parse sub-calendars embedded in page: FEdsDS -  - Deployed v.11 (2203666870)
   com.atlassian.confluence.content.render.xhtml.XhtmlException: RuntimeException occurred while performing an XHTML storage transformation (null)
   

3. Even with above error pages are indexed correctly and are available in search

Expected Results

The indexer should throw a more informative error. If macro-id and macro-name is missing it shouldn't default to calendar parser

Actual Results

Following error is thrown which is misleading

2021-04-17 13:35:23,515 WARN [Indexer: 21] [confluence.extra.calendar3.DefaultEmbeddedSubCalendarsParser] getEmbeddedSubCalendarIds Unable to parse sub-calendars embedded in page: FEdsDS -  - Deployed v.11 (2203666870)
com.atlassian.confluence.content.render.xhtml.XhtmlException: RuntimeException occurred while performing an XHTML storage transformation (null)

Workaround

Reinsert the attachments to the pages so that the correct format is present