When a text box is edited in order to merge text the following will happen:

• clicking the edit icon triggers a font style change to wikitext layout.
• this change will be triggered on both the selected and unselected version to provide an easier orientation to compare the changes
• the text box being edited switches icons to
  • a check mark (pre-save changes in this box without leaving the site) and
  • a back arrow (undo my changes): this will reset all changes done in this text box. (Note just now: We should provide a confirmation prompt to reset all changes or just do a reset of the past small changes – otherwise this could be really frustrating)