The following applies only to Mercurial (hg) repositories. For GIT repositories, the Skara tooling provides jcheck.
The various JDK projects on OpenJDK, e.g., jdk9, use jcheck to check the content and commit message of each changeset that goes into the repo. See the jcheck page for more information about jcheck, and the OpenJDK Producing a Changeset page for the required format of commit messages.
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