Release notes for Gerrit 2.1.6

HistogramDiff is an adaptation of Bram Cohen’s Patience Difference algorithm, and was recently included in the upstream JGit project. Patience Difference tends to produce more readable differences for source code files, and JGit’s HistogramDiff implementation tends to run several times faster than the prior Myers O(ND) algorithm.

Project owners can now enable file-level content merge during submit, allowing Gerrit to automatically resolve many path conflict cases. This is built upon experimental merge code inherited from JGit, and is therefore still experimental in Gerrit.

Similar to other features in Gerrit Code Review, starting any of these expressions with \^ will now treat the argument as a regular expression instead of an exact string match.

The new flag includes approval information for all patch sets in the resulting query output.

Email notifications are now driven by the Velocity template engine, and may be modified by the site administrator by editing a template file under '$site_path'/etc/mail.

The default email notification formatting was changed to make the subject lines and message bodies more consistent, and easier to understand.

The project list panel makes it easier for users to browse all projects they have at least READ +1 access to, and add them to their watched project set so notifications can be configured.

Whenever a ref is updated via either a direct push to a branch or a Gerrit change submission, Gerrit will now send a new "ref-updated" event to the event stream.

A new auth.type of CLIENT_SSL_CERT_LDAP supports authenticating users using client SSL certificates. This feature requires using the embedded Jetty web server with SSL enabled, and an LDAP directory to lookup individual account information.

Administrators can manually update the accounts table, setting inactive = Y to mark user accounts inactive. Inactive accounts cannot sign-in, cannot be added as a reviewer, and cannot be added to a group.

Instead of giving a short no shell available error, Gerrit Code Review now prints a banner letting the user know they have authenticated successfully, interactive shells are disabled, and how to clone a hosted project:

The internal SSH daemon now supports additional configuration settings to reduce the risk of abuse.

The new system group Project Owners can be used in access rights to mean any user that is a member of any group that has the Owner access category granted within that project. This system group is primarily useful in higher level projects such as -- All Projects -- to define standard access rights for all project owners.

Project owners can set a flag to require all commits to include the Gerrit specific Change-Id: I… line during initial upload, reducing the risk of confusion when amends need to occur to incorporate reviewer feedback.

The new flag skips creating the associated Git repository, making the new project suitable for use as a parent to inherit permissions from.

The repo tool used by Android doesn’t like to clone an empty Git repository, making it difficult to setup a review for the initial file contents. create-project can now optionally create an empty initial commit, permitting repo to sync the empty project.

The upload.allowGroup and receive.allowGroup settings in gerrit.config can be used to restrict which users can perform git clone/fetch or git push on this server. This can be useful if clone/fetch should be limited to only site administrators, while normal users are supposed to use to less expensive mirror servers.

The automatic replicate every project action that occurs during server startup can now be disabled by setting replicateOnStartup = false. This is primarily useful for sites with extremely large numbers of projects and replication targets, but runs the risk of having a target be out of date relative to the master server.

Site defined approval categories may now use the function "NoBlock" to permit scoring without blocking submission. This is mostly useful for automated tools to provide optional feedback on a change.

The Git-note style branch refs/meta/reject-commits can be created by the project owner or site administrator to define a list of commits that must not be pushed into the repository. This can be useful after performing a project-wide filter-branch operation to prevent the older (pre-filter-branch) history from being reintroduced into the repository.

MyersDiff sometimes locked up in an infinite loop when computing the intraline difference information for a file. These threads are now killed after an administrator specified timeout (cache.diff_intraline.timeout, default is 5 seconds). If the timeout is reached the file content is displayed without intraline differences. This offers reduced functionality to the end-user, but prevents the "path of death" which usually took down a Gerrit server.

Users were able to view access rights for branches they didn’t actually have READ +1 permission on. This may have leaked information about branches and/or groups to users that shouldn’t know about code names contained within either string. Users that are not project owners may now only view access rights for branches they have at least READ +1 permission on.

Correcting only the author of a change failed to upload the new patch set onto the existing change, as neither the message nor the files were modified. Fixed.

Previously it was not possible to replace a tag object, even if git push \--force was used. Fixed.

If a server repository was corrupted by an administrator manually creating a reference within the magical refs/for/ namespace, Gerrit became confused when changes were uploaded for review. If this case occurs push now aborts very early, with a clear error message indicating the problem. To recover an administrator must clear the refs/for/ namespace manually.

Users who had direct branch push permission but lacked the ability to create changes for review were unable to push to a project. Fixed. This (finally) makes Gerrit a replacement for Gitosis or Gitolite.

Previously a misconfigured authGroup in replication.config may have caused the server to assume "Registered Users" instead of the group(s) admin actually wanted. This may have caused the replication to see (or not see) the correct set of projects.

If replication fails (for example due to temporary network connectivity problems), other pending replication events to the same server are deferred and retried later until successful.

Replication now replicates all references, not just those that appear under refs/heads, refs/tags, or refs/changes. This fix may be relevant if the server supports user-private sandboxes such as refs/dev/'$\{username\}'/*.

Some special characters may appear in LDAP group names, these must be escape when looking up the group information from JNDI, otherwise the lookup fails. Fixed by applying the necessary escape sequences.

If the user name for a new account is supposed to import from LDAP but cannot because it is already in use by another user on this server, the new account won’t be created.

Previously gerrit.sh check claimed a server was running if the pid file was present, even if the process itself was dead. It now checks ps for the process before claiming it is running.

Exclusive branch level rights prevented the a higher level branch owner from managing the branch rights, unless they had an additional access right for the exclusive rights. Now Owner inheritance cannot be blocked, ensuring that the higher level owner can manage their entire namespace.

Permissions in the parent project could not be overridden in the child project. Permissions can now be overidden if the category, group name and reference name all match.