Issue Summary

Adding an 'Expand' macro within a 'Panel' macro adds a line break, which enlarges the Panel body when viewed in view mode.

This is reproducible on Data Center: yes

Steps to Reproduce

1. Add Panel Macro on a Page.
2. Add expand macro within the Panel macro.
3. Publish/Update the page.

Expected Results

The Panel macro body should be normal without any line breaks or white spaces (as shown in the attached image_1).

This is working as expected in Confluence v7.19.x. 

Actual Results

The body of the Panel macro contains line breaks or white spaces (as shown in the attached image_2), which detracts from its overall aesthetic appeal.

Observation

When tested in Confluence v7.19.x, class "auto-cursor-target" is added by default, which prevents a line break within the panel macro.

<ac:structured-macro ac:macro-id="4ff5b5b1-4729-47f6-a3b3-f3c5ac85bca7" ac:name="panel" ac:schema-version="1">
  <ac:rich-text-body>
    <p class="auto-cursor-target">
      <br/>
    </p>
    <ac:structured-macro ac:macro-id="ed85bdff-1693-4804-b892-fcedb79e3f4e" ac:name="expand" ac:schema-version="1">
      <ac:rich-text-body>
        <p>
          <br/>
        </p>
      </ac:rich-text-body>
    </ac:structured-macro>
    <p class="auto-cursor-target">
      <br/>
    </p>
  </ac:rich-text-body>
</ac:structured-macro>

However in Confluence 8.5.x version, we see a line break in the Panel macro instead of class "auto-cursor-target"

<ac:structured-macro ac:macro-id="2f892009-4934-451a-a56b-1c367644f886" ac:name="panel" ac:schema-version="1">
  <ac:rich-text-body>
    <ac:structured-macro ac:macro-id="1864580b-72b2-4d72-85fc-b55b222e8991" ac:name="expand" ac:schema-version="1">
      <ac:rich-text-body>
        <p>
          <br/>
        </p>
      </ac:rich-text-body>
    </ac:structured-macro>
    <p>
      <br/>
    </p>
  </ac:rich-text-body>
</ac:structured-macro>

Workaround

Two workarounds are possible at the moment.

1. Remove line break in the Panel macro HTML code using the source editor

        <p>
          <br/>
        </p>

2. Add class 'auto-cursor-target' in the Panel macro code to remove the line break using the source editor.

 <p class="auto-cursor-target">
      <br/>
    </p>