Clean-up the template loading code. (#9200)

* Enables autoescape by default for HTML files.
* Adds a new read_template method for reading a single template.
* Some logic clean-up.

1 files changed, 37 insertions, 0 deletions

diff --git a/UPGRADE.rst b/UPGRADE.rst
index d09dbd4e21..e62e647a1d 100644
--- a/UPGRADE.rst
+++ b/UPGRADE.rst
@@ -85,6 +85,43 @@ for example:
      wget https://packages.matrix.org/debian/pool/main/m/matrix-synapse-py3/matrix-synapse-py3_1.3.0+stretch1_amd64.deb
      dpkg -i matrix-synapse-py3_1.3.0+stretch1_amd64.deb
 
+Upgrading to v1.27.0
+====================
+
+Changes to HTML templates
+-------------------------
+
+The HTML templates for SSO and email notifications now have `Jinja2's autoescape <https://jinja.palletsprojects.com/en/2.11.x/api/#autoescaping>`_
+enabled for files ending in ``.html``, ``.htm``, and ``.xml``. If you hae customised
+these templates and see issues when viewing them you might need to update them.
+It is expected that most configurations will need no changes.
+
+If you have customised the templates *names* for these templates it is recommended
+to verify they end in ``.html`` to ensure autoescape is enabled.
+
+The above applies to the following templates:
+
+* ``add_threepid.html``
+* ``add_threepid_failure.html``
+* ``add_threepid_success.html``
+* ``notice_expiry.html``
+* ``notice_expiry.html``
+* ``notif_mail.html`` (which, by default, includes ``room.html`` and ``notif.html``)
+* ``password_reset.html``
+* ``password_reset_confirmation.html``
+* ``password_reset_failure.html``
+* ``password_reset_success.html``
+* ``registration.html``
+* ``registration_failure.html``
+* ``registration_success.html``
+* ``sso_account_deactivated.html``
+* ``sso_auth_bad_user.html``
+* ``sso_auth_confirm.html``
+* ``sso_auth_success.html``
+* ``sso_error.html``
+* ``sso_login_idp_picker.html``
+* ``sso_redirect_confirm.html``
+
 Upgrading to v1.26.0
 ====================