Steps to reproduce:
1. Prepare a new eZ Publish 5.4.5 installation;
2. On the admin SA, create a new article;
3. Fill in the required details, and then on an existing XML block field such as "Body", disable the online editor, and paste the following example text:
<li><anchor name="a13D" />Amendments to the constitution must then be reviewed by the Executive Council, which will, in a timely manner, either forward to the membership the amendment as approved or with nonsubstantive modifications or determine that it is unable to forward the amendment to the membership for one or both of the following reasons:
<li><anchor name="a13D1" />The amendment impedes the council's ability to carry out its fiduciary responsibilities.</li>
<li><anchor name="a13D2" />The amendment, by itself or taken with other amendments, poses a threat to the association's continuing operation as a tax-exempt organization.</li>
If the council is unable to forward an amendment to the membership, it will, at the next meeting of the Delegate Assembly, present the reasons for its action. The Delegate Assembly may then consider reformulating the amendment.
5. Examine the article on a frontend siteaccess, and notice that a line break has been inserted before "If the council is unable (...)". A simple code inspection on the browser will confirm that. Verified on Chrome 46, FF 41 and IE11 so it's not specific to a single browser.
See attached screenshot.