Table of Contents (TOC) macro displays headings from the comment section

Problem

When adding the Table of Contents (TOC) macro to a page, the same will list all the headings from the page, as expected, but now it is also displaying headings added to comments to the same page:

Environment

Confluence 7.12.3, 7.12.4, and 7.13.0.

Steps to Reproduce

1. # Create a Confluence page.
2. In the page editor, add a Table of Contents (TOC) macro. The macro doesn't require any specific configuration.
3. Add some headings to the body of the page.
4. Save the page. You will see the macro listing the headings.
5. Add a comment that contains any heading and refresh the page.
6. You will see the macro listing the headings from the page body and the headings from the comment section

Expected Results

On Confluence 7.12.2 and lower versions, the macro only lists the headings added to the page body.

Workaround

Remove the headings from the comments of pages that contain the TOC macro.