The "reparent" command:

Usage: fossil reparent [OPTIONS] CHECK-IN PARENT ...

Create a "parent" tag that causes CHECK-IN to be interpreted as a child of PARENT. If multiple PARENTs are listed, then the first is the primary parent and others are merge ancestors.

This is an experts-only command. It is used to patch up a repository that has been damaged by a shun or that has been pieced together from two or more separate repositories. You should never need to reparent during normal operations.

Reparenting is accomplished by adding a parent tag. So to undo the reparenting operation, simply delete the tag.

--test

Make database entries but do not add the tag artifact. So the reparent operation will be undone by the next "fossil rebuild" command.

--dryrun | -n

Print the tag that would have been created but do not actually change the database in any way.

--date-override DATETIME

Set the change time on the control artifact

--user-override USER

Set the user name on the control artifact