Newlines get added around macros in WYSIWYG editor

This is related to CONF-7628 but it's not fixed in version 2.5.4.

When I use the WYSIWYG editor and place a macro on a line of text, I can save the page and it renders just fine. But then if I edit the page in the WYSIWYG editor again, something is adding newlines around the macro. This means I can't use a macro "in-line" with other text.

HOW TO REPRODUCE:

1. Edit a page with the WYSIWYG editor and add this text, using braces instead of "<>":
Before <metadata-from:Parent> after.

2. Save and view the page: it will look right, with the word "Before," then the macro expansion, then the word "after" all on one line.

3. Now edit the page again with the WYSIWYG editor. You will see multiple newlines around the macro's braces, like this:

Up to
<metadata-from:Parent>

my parent page.

If you save the page without making any changes, the page will render with the newlines, so now you see "Before," then a line break, then the parent page's name, then another line break, then the word "after."

Unlike earlier reported bugs, repeated WYSIWYG editing at this point does not add any additional line breaks. But this bug does mean you can't use "in-line" macros like this; macros can only be used with line breaks around them. This limits the usability of the WYSIWYG editor.