Sometimes a user will have an error in her log message (a misspelling or some misinformation, perhaps). If the repository is configured (using the pre-revprop-change hook; see Implementing Repository Hooks) to accept changes to this log message after the commit is finished, the user can “fix” her log message remotely using svn propset (see “svn propset” in Chapter 9). However, because of the potential to lose information forever, Subversion repositories are not, by default, configured to allow changes to unversioned properties—except by an administrator.

If a log message needs to be changed by an administrator, this can be done using svnadmin setlog. This command changes the log message (the svn:log property) on a given revision of a repository, reading the new value from a provided file:

$ echo "Here is the new, correct log message" > newlog.txt
$ svnadmin setlog myrepos newlog.txt -r 388

The svnadmin setlog command, by default, is still bound by the same protections against modifying unversioned properties as a remote client—the pre- and post-revprop-change hooks are still triggered and therefore must be set up to accept changes of this nature. But an administrator can get around these protections by passing the --bypass-hooks option to the svnadmin setlog command.