Created attachment 283758 [details]
minimal example

I have a set of documentation with multiple markdown pages. These pages often have the same structure, e.g. they start with an Overview/Introduction, before going into further details of the topic.

This used to work fine in Doxygen 1.8.6, but as of 1.8.7 (including today's Git build) Doxygen complains about "multiple use of section label" on these pages - even though the section anchors are different.

On pages where such a duplicate label is found all content after that label is simply removed, rendering the page pretty much empty.

I use the "Label {#anchor}" syntax to define the sections.

I have attached a minimal example that exposes this behavior. There are two .md files (under related pages in the HTML output) - see attachment. The first page is generated as expected, but the second page is broken.

Changing the label text of the second page makes thing work as expected again, but means the headings will have to be unique across the whole project - rather than just the anchors.

This may be related to #734727.