Exporting to PDF results in images incorrectly rearranged in PDF when using LaTex plugin in a page

Hi,

I use WritableDownloadResourceManager to include rendered macros in Confluence pages as PNGs. Under certain circumstances, these images are sometimes rearranged in the final output. I've included an example of the page output (as expected) and the PDF output (with rearranged images). The PDF output seems to be consistently wrong on every second rendering.

I could not reproduce the error when exporting an entire space, only when exporting a single page with ... -> Export to PDF.

The URLs in the macro output match the images written to Confluence's temp folder (in the correct order).

This can be seen in production in the marketplace add-on Latex Math.

Testing was done on Confluence 6.7.0.

Support ticket: https://ecosystem.atlassian.net/browse/DEVHELP-985

Steps:

1. Spawn a Confluence Server 6.7.0
2. Install LaTex Math plugin
3. Create a new page and add a LaTex inline macro or if you have a source editor plugin, use this:

   <p>aa&nbsp;<ac:structured-macro ac:name="mathinline" ac:schema-version="1" ac:macro-id="294304a0-2b09-496e-942e-c90f2e804b7e"><ac:parameter ac:name="body">aaaaaa</ac:parameter></ac:structured-macro></p>
   <p>bb&nbsp;<ac:structured-macro ac:name="mathinline" ac:schema-version="1" ac:macro-id="0d66f4d1-fa02-4c96-9ccd-937c519215fd"><ac:parameter ac:name="body">bbbbbb</ac:parameter></ac:structured-macro></p>
   <p>cc&nbsp;<ac:structured-macro ac:name="mathinline" ac:schema-version="1" ac:macro-id="7f07a0ff-027b-41a2-87c1-8d0605e81b48"><ac:parameter ac:name="body">cccccc</ac:parameter></ac:structured-macro></p>
   <p>dd&nbsp;<ac:structured-macro ac:name="mathinline" ac:schema-version="1" ac:macro-id="4f267650-be81-420e-bd1c-38f2821344e2"><ac:parameter ac:name="body">dddddd</ac:parameter></ac:structured-macro></p>
   <p>ee&nbsp;<ac:structured-macro ac:name="mathinline" ac:schema-version="1" ac:macro-id="45369f7f-b322-4840-8035-6d73dd1db6d3"><ac:parameter ac:name="body">eeeeee</ac:parameter></ac:structured-macro></p>
   <p>ff&nbsp;<ac:structured-macro ac:name="mathinline" ac:schema-version="1" ac:macro-id="20efbb6a-be02-4630-9567-a5d4d0dac23d"><ac:parameter ac:name="body">ffffff</ac:parameter></ac:structured-macro></p>
   <p>gg&nbsp;<strong><ac:structured-macro ac:name="mathinline" ac:schema-version="1" ac:macro-id="c00a223b-afc1-499c-83c4-227ddbd20b3d"><ac:parameter ac:name="body">gggggg</ac:parameter></ac:structured-macro></strong></p>
   

4. Notice the difference when the page is published and when you export the page to PDF for several times (see attached PDF for reference as well)

Workaround

None