merge(third_party/git): Merge squashed git subtree at v2.23.0

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third_party/git/contrib/hooks/multimail/doc/gitolite.rst

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+Setting up git-multimail on gitolite
+====================================
+
+``git-multimail`` supports gitolite 3 natively.
+The explanations below show an easy way to set up ``git-multimail``,
+but leave ``git-multimail`` installed and unconfigured for a while. If
+you run gitolite on a production server, it is advised that you
+execute the step "Set up the hook" last to avoid confusing your users
+in the meantime.
+
+Set up the hook
+---------------
+
+Log in as your gitolite user.
+
+Create a file ``.gitolite/hooks/common/post-receive`` on your gitolite
+account containing (adapt the path, obviously)::
+
+  #!/bin/sh
+  exec /path/to/git-multimail/git-multimail/git_multimail.py "$@"
+
+Make sure it's executable (``chmod +x``). Record the hook in
+gitolite::
+
+  gitolite setup
+
+Configuration
+-------------
+
+First, you have to allow the admin to set Git configuration variables.
+
+As gitolite user, edit the line containing ``GIT_CONFIG_KEYS`` in file
+``.gitolite.rc``, to make it look like::
+
+  GIT_CONFIG_KEYS                 =>  'multimailhook\..*',
+
+You can now log out and return to your normal user.
+
+In the ``gitolite-admin`` clone, edit the file ``conf/gitolite.conf``
+and add::
+
+  repo @all
+      # Not strictly needed as git_multimail.py will chose gitolite if
+      # $GL_USER is set.
+      config multimailhook.environment = gitolite
+      config multimailhook.mailingList = # Where emails should be sent
+      config multimailhook.from = # From address to use
+
+Note that by default, gitolite forbids ``<`` and ``>`` in variable
+values (for security/paranoia reasons, see
+`compensating for UNSAFE_PATT
+<http://gitolite.com/gitolite/git-config/index.html#compensating-for-unsafe95patt>`__
+in gitolite's documentation for explanations and a way to disable
+this). As a consequence, you will not be able to use ``First Last
+<First.Last@example.com>`` as recipient email, but specifying
+``First.Last@example.com`` alone works.
+
+Obviously, you can customize all parameters on a per-repository basis by
+adding these ``config multimailhook.*`` lines in the section
+corresponding to a repository or set of repositories.
+
+To activate ``git-multimail`` on a per-repository basis, do not set
+``multimailhook.mailingList`` in the ``@all`` section and set it only
+for repositories for which you want ``git-multimail``.
+
+Alternatively, you can set up the ``From:`` field on a per-user basis
+by adding a ``BEGIN USER EMAILS``/``END USER EMAILS`` section (see
+``../README``).
+
+Specificities of Gitolite for Configuration
+-------------------------------------------
+
+Empty configuration variables
+.............................
+
+With gitolite, the syntax ``config multimailhook.commitList = ""``
+unsets the variable instead of setting it to an empty string (see
+`here
+<http://gitolite.com/gitolite/git-config.html#an-important-warning-about-deleting-a-config-line>`__).
+As a result, there is no way to set a variable to the empty string.
+In all most places where an empty value is required, git-multimail
+now allows to specify special ``"none"`` value (case-sensitive) to
+mean the same.
+
+Alternatively, one can use ``" "`` (a single space) instead of ``""``.
+In most cases (in particular ``multimailhook.*List`` variables), this
+will be equivalent to an empty string.
+
+If you have a use-case where ``"none"`` is not an acceptable value and
+you need ``" "`` or  ``""`` instead, please report it as a bug to
+git-multimail.
+
+Allowing Regular Expressions in Configuration
+.............................................
+
+gitolite has a mechanism to prevent unsafe configuration variable
+values, which prevent characters like ``|`` commonly used in regular
+expressions. If you do not need the safety feature of gitolite and
+need to use regular expressions in your configuration (e.g. for
+``multimailhook.refFilter*`` variables), set
+`UNSAFE_PATT
+<http://gitolite.com/gitolite/git-config.html#unsafe-patt>`__ to a
+less restrictive value.
+
+Troubleshooting
+---------------
+
+Warning: this will disable ``git-multimail`` during the debug, and
+could confuse your users. Don't run on a production server.
+
+To debug configuration issues with ``git-multimail``, you can add the
+``--stdout`` option when calling ``git_multimail.py`` like this::
+
+  #!/bin/sh
+  exec /path/to/git-multimail/git-multimail/git_multimail.py --stdout "$@"
+
+and try pushing from a test repository. You should see the source of
+the email that would have been sent in the output of ``git push``.