When you are fixing bugs, please follow these best-practices:

• All bug fixes, even very minor, should have a JIRA task associated with them, so that we can track what happened in each release, without having to go to the commit logs.
• Be verbose in your commit comments, explaining the changes made.
• Attach a link to the Jira task to the commit message of the files you are comitting for the bug,
  ie. "Fixed a logging error, see the bug report here: http://jira.codehaus.org/browse/GEOS-583"
• Try to commit all of the files related to a bug (or improvement) in one commit so they can be rolled back easier. Or at least in logical chunks.
• When you close the task in Jira, put the version numbers of the commits. Such as "r4382".
• If you're committing a patch, use the unix patch command (patch -p0 < file.patch) to ensure that it matches exactly. Give the person who submitted the patch credit on the commit comment.