Merge tag 'v0.33.9' 0.34.0rc2

Features
--------

- Include flags to optionally add `m.login.terms` to the registration flow when consent tracking is enabled.
([\#4004](https://github.com/matrix-org/synapse/issues/4004), [\#4133](https://github.com/matrix-org/synapse/issues/4133),
[\#4142](https://github.com/matrix-org/synapse/issues/4142), [\#4184](https://github.com/matrix-org/synapse/issues/4184))
- Support for replacing rooms with new ones ([\#4091](https://github.com/matrix-org/synapse/issues/4091), [\#4099](https://github.com/matrix-org/synapse/issues/4099),
[\#4100](https://github.com/matrix-org/synapse/issues/4100), [\#4101](https://github.com/matrix-org/synapse/issues/4101))

Bugfixes
--------

- Fix exceptions when using the email mailer on Python 3. ([\#4095](https://github.com/matrix-org/synapse/issues/4095))
- Fix e2e key backup with more than 9 backup versions ([\#4113](https://github.com/matrix-org/synapse/issues/4113))
- Searches that request profile info now no longer fail with a 500. ([\#4122](https://github.com/matrix-org/synapse/issues/4122))
- fix return code of empty key backups ([\#4123](https://github.com/matrix-org/synapse/issues/4123))
- If the typing stream ID goes backwards (as on a worker when the master restarts), the worker's typing handler will no longer erroneously report rooms containing new
typing events. ([\#4127](https://github.com/matrix-org/synapse/issues/4127))
- Fix table lock of device_lists_remote_cache which could freeze the application ([\#4132](https://github.com/matrix-org/synapse/issues/4132))
- Fix exception when using state res v2 algorithm ([\#4135](https://github.com/matrix-org/synapse/issues/4135))
- Generating the user consent URI no longer fails on Python 3. ([\#4140](https://github.com/matrix-org/synapse/issues/4140),
[\#4163](https://github.com/matrix-org/synapse/issues/4163))
- Loading URL previews from the DB cache on Postgres will no longer cause Unicode type errors when responding to the request, and URL previews will no longer fail if
the remote server returns a Content-Type header with the chartype in quotes. ([\#4157](https://github.com/matrix-org/synapse/issues/4157))
- The hash_password script now works on Python 3. ([\#4161](https://github.com/matrix-org/synapse/issues/4161))
- Fix noop checks when updating device keys, reducing spurious device list update notifications. ([\#4164](https://github.com/matrix-org/synapse/issues/4164))

Deprecations and Removals
-------------------------

- The disused and un-specced identicon generator has been removed. ([\#4106](https://github.com/matrix-org/synapse/issues/4106))
- The obsolete and non-functional /pull federation endpoint has been removed. ([\#4118](https://github.com/matrix-org/synapse/issues/4118))
- The deprecated v1 key exchange endpoints have been removed. ([\#4119](https://github.com/matrix-org/synapse/issues/4119))
- Synapse will no longer fetch keys using the fallback deprecated v1 key exchange method and will now always use v2.
([\#4120](https://github.com/matrix-org/synapse/issues/4120))

Internal Changes
----------------

- Fix build of Docker image with docker-compose ([\#3778](https://github.com/matrix-org/synapse/issues/3778))
- Delete unreferenced state groups during history purge ([\#4006](https://github.com/matrix-org/synapse/issues/4006))
- The "Received rdata" log messages on workers is now logged at DEBUG, not INFO. ([\#4108](https://github.com/matrix-org/synapse/issues/4108))
- Reduce replication traffic for device lists ([\#4109](https://github.com/matrix-org/synapse/issues/4109))
- Fix `synapse_replication_tcp_protocol_*_commands` metric label to be full command name, rather than just the first character
([\#4110](https://github.com/matrix-org/synapse/issues/4110))
- Log some bits about room creation ([\#4121](https://github.com/matrix-org/synapse/issues/4121))
- Fix `tox` failure on old systems ([\#4124](https://github.com/matrix-org/synapse/issues/4124))
- Add STATE_V2_TEST room version ([\#4128](https://github.com/matrix-org/synapse/issues/4128))
- Clean up event accesses and tests ([\#4137](https://github.com/matrix-org/synapse/issues/4137))
- The default logging config will now set an explicit log file encoding of UTF-8. ([\#4138](https://github.com/matrix-org/synapse/issues/4138))
- Add helpers functions for getting prev and auth events of an event ([\#4139](https://github.com/matrix-org/synapse/issues/4139))
- Add some tests for the HTTP pusher. ([\#4149](https://github.com/matrix-org/synapse/issues/4149))
- add purge_history.sh and purge_remote_media.sh scripts to contrib/ ([\#4155](https://github.com/matrix-org/synapse/issues/4155))
- HTTP tests have been refactored to contain less boilerplate. ([\#4156](https://github.com/matrix-org/synapse/issues/4156))
- Drop incoming events from federation for unknown rooms ([\#4165](https://github.com/matrix-org/synapse/issues/4165))

2 files changed, 47 insertions, 7 deletions

diff --git a/docs/consent_tracking.md b/docs/consent_tracking.md

index 064eae82f7..c586b5f0b6 100644
--- a/docs/consent_tracking.md
+++ b/docs/consent_tracking.md
@@ -31,7 +31,7 @@ Note that the templates must be stored under a name giving the language of the
 template - currently this must always be `en` (for "English");
 internationalisation support is intended for the future.
 
-The template for the policy itself should be versioned and named according to 
+The template for the policy itself should be versioned and named according to
 the version: for example `1.0.html`. The version of the policy which the user
 has agreed to is stored in the database.
 
@@ -85,6 +85,37 @@ Once this is complete, and the server has been restarted, try visiting
 an error "Missing string query parameter 'u'". It is now possible to manually
 construct URIs where users can give their consent.
 
+### Enabling consent tracking at registration
+
+1. Add the following to your configuration:
+
+   ```yaml
+   user_consent:
+     require_at_registration: true
+     policy_name: "Privacy Policy" # or whatever you'd like to call the policy
+   ```
+
+2. In your consent templates, make use of the `public_version` variable to
+   see if an unauthenticated user is viewing the page. This is typically
+   wrapped around the form that would be used to actually agree to the document:
+
+   ```
+   {% if not public_version %}
+     <!-- The variables used here are only provided when the 'u' param is given to the homeserver -->
+     <form method="post" action="consent">
+       <input type="hidden" name="v" value="{{version}}"/>
+       <input type="hidden" name="u" value="{{user}}"/>
+       <input type="hidden" name="h" value="{{userhmac}}"/>
+       <input type="submit" value="Sure thing!"/>
+     </form>
+   {% endif %}
+   ```
+
+3. Restart Synapse to apply the changes.
+
+Visiting `https://<server>/_matrix/consent` should now give you a view of the privacy
+document. This is what users will be able to see when registering for accounts.
+
 ### Constructing the consent URI
 
 It may be useful to manually construct the "consent URI" for a given user - for
@@ -106,6 +137,12 @@ query parameters:
    `https://<server>/_matrix/consent?u=<user>&h=68a152465a4d...`.
 
 
+Note that not providing a `u` parameter will be interpreted as wanting to view
+the document from an unauthenticated perspective, such as prior to registration.
+Therefore, the `h` parameter is not required in this scenario. To enable this
+behaviour, set `require_at_registration` to `true` in your `user_consent` config.
+
+
 Sending users a server notice asking them to agree to the policy
 ----------------------------------------------------------------
 
diff --git a/docs/privacy_policy_templates/en/1.0.html b/docs/privacy_policy_templates/en/1.0.html

index 55c5e4b612..321c7e4671 100644
--- a/docs/privacy_policy_templates/en/1.0.html
+++ b/docs/privacy_policy_templates/en/1.0.html
@@ -12,12 +12,15 @@
     <p>
       All your base are belong to us.
     </p>
-    <form method="post" action="consent">
-      <input type="hidden" name="v" value="{{version}}"/>
-      <input type="hidden" name="u" value="{{user}}"/>
-      <input type="hidden" name="h" value="{{userhmac}}"/>
-      <input type="submit" value="Sure thing!"/>
-    </form>
+    {% if not public_version %}
+      <!-- The variables used here are only provided when the 'u' param is given to the homeserver -->
+      <form method="post" action="consent">
+        <input type="hidden" name="v" value="{{version}}"/>
+        <input type="hidden" name="u" value="{{user}}"/>
+        <input type="hidden" name="h" value="{{userhmac}}"/>
+        <input type="submit" value="Sure thing!"/>
+      </form>
+    {% endif %}
   {% endif %}
   </body>
 </html>