d6b8b5ba73 2009-08-26       drh: <title>Deleting Content From Fossil</title>
d6b8b5ba73 2009-08-26       drh: <h1 align="center">Deleting Content From Fossil</h1>
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh: Fossil is designed to keep all historical content forever.  Users
d6b8b5ba73 2009-08-26       drh: of Fossil are discouraged from "deleting" content simply because it
d6b8b5ba73 2009-08-26       drh: has become obsolete.  Old content is part of the historical record
d6b8b5ba73 2009-08-26       drh: (part of the "fossil record") and should be maintained indefinitely.
d6b8b5ba73 2009-08-26       drh: Such is the design intent of Fossil.
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh: Nevertheless, there may occasionally arise legitimate reasons for
d6b8b5ba73 2009-08-26       drh: deleting content.  Such reasons might include:
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh:   *  Spammers have inserted inappropriate content into a wiki page
d6b8b5ba73 2009-08-26       drh:      or ticket that needs to be removed.
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh:   *  A file that contains trade secrets or that is under copyright
d6b8b5ba73 2009-08-26       drh:      may have been accidentally committed and needs to be backed
d6b8b5ba73 2009-08-26       drh:      out.
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh:   *  A malformed control artifact may have been inserted and is
d6b8b5ba73 2009-08-26       drh:      disrupting the operation of Fossil.
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh: <h2>Shunning</h2>
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh: Fossil provides a mechanism called "shunning" for removing content from
d6b8b5ba73 2009-08-26       drh: a repository.
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh: Every Fossil repository maintains a list of the SHA1 hash names of
d6b8b5ba73 2009-08-26       drh: "shunned" artifacts.
d6b8b5ba73 2009-08-26       drh: Fossil will refuse to push or pull any shunned artifact.
d6b8b5ba73 2009-08-26       drh: Furthermore, all shunned artifacts (but not the shunning list
d6b8b5ba73 2009-08-26       drh: itself) are removed from the
d6b8b5ba73 2009-08-26       drh: repository whenever the repository is reconstructed using the
d6b8b5ba73 2009-08-26       drh: "rebuild" command.
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh: <h3>Shunning lists are local state</h3>
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh: The shunning list is part of the local state of a Fossil repository.
d6b8b5ba73 2009-08-26       drh: In other words, shunning does not propagate using the normal "sync"
d6b8b5ba73 2009-08-26       drh: mechanism.  An artifact can be
d6b8b5ba73 2009-08-26       drh: shunned from one repository but be allowed to exist in another.  The fact that
d6b8b5ba73 2009-08-26       drh: the shunning list does not propagate is a security feature.  If the
d6b8b5ba73 2009-08-26       drh: shunning list propagated then a malecious user (or
d6b8b5ba73 2009-08-26       drh: a bug in the fossil code) might introduce a shun record that would
d6b8b5ba73 2009-08-26       drh: propagate through all respositories in a network and permanently
d6b8b5ba73 2009-08-26       drh: destroy vital information.  By refusing to propagate the shunning list,
d6b8b5ba73 2009-08-26       drh: Fossil insures that no remote user will ever be able to remove
d6b8b5ba73 2009-08-26       drh: information from your personal repositories without your permission.
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh: The shunning list does not propagate by the normal "sync" mechanism,
d6b8b5ba73 2009-08-26       drh: but it is still possible to copy shuns from one repository to another
d6b8b5ba73 2009-08-26       drh: using the "configuration" command:
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh:     <b>fossil configuration pull shun</b> <i>remote-url</i><br>
d6b8b5ba73 2009-08-26       drh:     <b>fossil configuration push shun</b> <i>remote-url</i>
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh: The two command above will pull or push shunning lists from or to
d6b8b5ba73 2009-08-26       drh: the <i>remote-url</i> indicated and merge the lists on the receiving
d6b8b5ba73 2009-08-26       drh: end.  "Admin" privilege on the remote server is required in order to
d6b8b5ba73 2009-08-26       drh: push a shun list.
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh: Note that the shunning list remains in the respository even after the
d6b8b5ba73 2009-08-26       drh: shunned artifact has been removed.  This is to prevent the artifact
d6b8b5ba73 2009-08-26       drh: from being reintroduced into the repository the next time it syncs with
d6b8b5ba73 2009-08-26       drh: another repository that has not shunned the artifact.
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh: <h3>Managing the shunning list</h3>
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh: The complete shunning list for a repository can be viewed by a user
d6b8b5ba73 2009-08-26       drh: with "admin" privilege on the "/shunned" URL of the web interface to Fossil.
d6b8b5ba73 2009-08-26       drh: That URL is accessible under the "Admin" button on the default menu
d6b8b5ba73 2009-08-26       drh: bar.  Items can be added to or removed from the shunning list.  "Sync"
d6b8b5ba73 2009-08-26       drh: operations are inhibited as soon as the artifact is added to the
d6b8b5ba73 2009-08-26       drh: shunning list, but the content of the artifact is not actually removed
d6b8b5ba73 2009-08-26       drh: from the responstory until the next time the repository is rebuilt.
d6b8b5ba73 2009-08-26       drh: 
d6b8b5ba73 2009-08-26       drh: When viewing individual artifacts with the web interface, "admin"
d6b8b5ba73 2009-08-26       drh: users will usually see a "Shun" option in the submenu that will take
d6b8b5ba73 2009-08-26       drh: them directly to the shunning page and enable that artifact to be
d6b8b5ba73 2009-08-26       drh: shunned with a single additional mouse click.