Issue 64890

I have a 325-pages odt file. The document has 4 levels of headings.

In this document, I have inserted a lot of hyperlinks that jump to headings.

The headings do not carry outline numbers. Yet, when I try to insert a hyperlink
in this document, the window shows headings with hierarchical numbers attached
to them.

For example, I have a hyperlink that jumps to a heading 2 titled "using
bookmarks". If I hover the mouse over the hyperlinked text, the following
tooltip is shown:

#7.4.Using bookmarks|Outline

(note the period after 7.4; and also the word "Outline" at the end)

I have not given this 7.4; nor can I actually see this number anywhere except
the hyperlink dialog. Nor is this heading supposed to be part of any outlining.

If it was only this issue, I would have tolerated it as a harmless nuisance. 

But this is far serious: After saving the file, when I reopen it, the hyperlink
is no longer able to jump to the target heading, because the "outline number" in
the link resets to zero, like this:

#0.0.Using bookmarks|Outline

To correct this, I have to edit the outline and re-insert the number (7.4) in
the place of 0.0

Worse, I do not know just how many links would be broken this way.
There is no tool/macro in Writer to find such broken links.

This seems to happen randomly: Just saving, closing the document and reopening
it does not seem to trigger this problem.