E-Merge supports one level of undo so that only the most current operation may be undone. After a merge operation is performed, it may be undone until another merge operation is performed, or until the application is closed. The most recent merge operation may be reversed (i.e., negated) using the Undo Merge tool button, or the Undo Merge command from the Edit menu.
If a merge operation that cannot be undone is attempted, a warning is displayed prior to the completion of the merge operation, and the merge operation may be cancelled.
When a merge operation is undone, the files and icons return to the status maintained prior to the merge operation. For example, if an unmerged file is included in a merge operation, the file would then be classified as “already merged”, and the icon for that file would receive a green checkmark. If the merge operation is subsequently undone, the file status would return to “unmerged”, and the green checkmark would be removed from the icon. In addition, the “Merge operation undone” message would be displayed in the Merge Log.