Remove legacy mentions (#2186)

Signed-off-by: Kévin Commaille <zecakeh@tedomum.fr>

changelogs/client_server/newsfragments/2186.removal

@@ -0,0 +1 @@
+Remove legacy mentions, as per [MSC4210](https://github.com/matrix-org/matrix-spec-proposals/issues/4210).

content/client-server-api/modules/mentions.md

@@ -3,6 +3,9 @@
 
 {{% changed-in v="1.7" %}}
 
+{{% changed-in v="1.17" %}}: the legacy push rules that looked for mentions in
+the `body` of the event were removed.
+
 This module allows users to "mention" other users and rooms within a room event.
 This is primarily used as an indicator that the recipient should receive a notification
 about the event.
@@ -38,19 +41,18 @@ encrypted as normal. To properly process mentions in encrypted rooms, events
 must be decrypted first. See [receiving notifications](#receiving-notifications).
 {{% /boxes/warning %}}
 
-Note that, for backwards compatibility, push rules such as [`.m.rule.contains_display_name`](#_m_rule_contains_display_name),
+{{% boxes/note %}}
-[`.m.rule.contains_user_name`](#_m_rule_contains_user_name), and
-[`.m.rule.roomnotif`](#_m_rule_roomnotif) continue to  match if the `body` of
-the event contains the user's display name or ID. To avoid unintentional notifications,
-**it is recommended that clients include a `m.mentions` property on each event**.
-(If there are no mentions to include it can be an empty object.)
-
-{{% boxes/rationale %}}
 In previous versions of the specification, mentioning users was done by
 including the user's display name or the localpart of their Matrix ID and room
 mentions were done by including the string "@room" in the plaintext `body` of
-the event. This was prone to confusing and buggy behaviour.
+the event. When the `m.mentions` field was introduced, those push rules were
-{{% /boxes/rationale %}}
+disabled if the `m.mentions` field was present.
+
+To avoid unintentional notifications with clients and servers that still use
+those push rules, **it is recommended that clients still include a `m.mentions`
+property on each event**. (If there are no mentions to include it can be an
+empty object.)
+{{% /boxes/note %}}
 
 #### Client behaviour
 

content/client-server-api/modules/push.md

@@ -382,6 +382,9 @@ The following `alt_aliases` values will NOT match:
 
 **`contains_display_name`**
 
+{{% changed-in v="1.17" %}}: this condition is deprecated and **should not be
+used in new push rules**.
+
 This matches messages where `content.body` contains the owner's display name in
 that room. This is a separate condition because display names may change and as such
 it would be hard to maintain a rule that matched the user's display name. This
@@ -413,6 +416,9 @@ Parameters:
 
 #### Predefined Rules
 
+{{% changed-in v="1.17" %}}: the legacy default push rules that looked for
+mentions in the `body` of the event were removed.
+
 Homeservers can specify "server-default rules". They operate at a lower
 priority than "user-defined rules", except for the `.m.rule.master` rule
 which has always a higher priority than any other rule. The `rule_id`
@@ -557,41 +563,6 @@ Definition:
 }
 ```
 
-<a id="_m_rule_contains_display_name"></a> **`.m.rule.contains_display_name`**
-
-{{% changed-in v="1.7" %}}
-
-As of `v1.7`, this rule is deprecated and **should only be enabled if the event
-does not have an [`m.mentions` property](#definition-mmentions)**.
-
-Matches any message whose content contains the user's current display name
-in the room in which it was sent.
-
-Definition:
-
-```json
-{
-    "rule_id": ".m.rule.contains_display_name",
-    "default": true,
-    "enabled": true,
-    "conditions": [
-        {
-            "kind": "contains_display_name"
-        }
-    ],
-    "actions": [
-        "notify",
-        {
-            "set_tweak": "sound",
-            "value": "default"
-        },
-        {
-            "set_tweak": "highlight"
-        }
-    ]
-}
-```
-
 <a id="_m_rule_is_room_mention"></a> **`.m.rule.is_room_mention`**
 
 {{% added-in v="1.7" %}}
@@ -626,44 +597,6 @@ Definition:
 }
 ```
 
-<a id="_m_rule_roomnotif"></a> **`.m.rule.roomnotif`**
-
-{{% changed-in v="1.7" %}}
-
-As of `v1.7`, this rule is deprecated and **should only be enabled if the event
-does not have an [`m.mentions` property](#definition-mmentions)**.
-
-Matches any message from a sender with the proper power level whose content
-contains the text `@room`, signifying the whole room should be notified of
-the event.
-
-Definition:
-
-```json
-{
-    "rule_id": ".m.rule.roomnotif",
-    "default": true,
-    "enabled": true,
-    "conditions": [
-        {
-            "kind": "event_match",
-            "key": "content.body",
-            "pattern": "@room"
-        },
-        {
-            "kind": "sender_notification_permission",
-            "key": "room"
-        }
-    ],
-    "actions": [
-        "notify",
-        {
-            "set_tweak": "highlight"
-        }
-    ]
-}
-```
-
 **<a id="mruletombstone"></a>`.m.rule.tombstone`**
 
 Matches any state event whose type is `m.room.tombstone`. This is
@@ -776,39 +709,6 @@ Definition:
 }
 ```
 
-##### Default Content Rules
-
-<a id="_m_rule_contains_user_name"></a> **`.m.rule.contains_user_name`**
-
-{{% changed-in v="1.7" %}}
-
-As of `v1.7`, this rule is deprecated and **should only be enabled if the event
-does not have an [`m.mentions` property](#definition-mmentions)**.
-
-Matches any message whose content contains the local part of the user's
-Matrix ID, separated by word boundaries.
-
-Definition (as a `content` rule):
-
-```json
-{
-    "rule_id": ".m.rule.contains_user_name",
-    "default": true,
-    "enabled": true,
-    "pattern": "[the local part of the user's Matrix ID]",
-    "actions": [
-        "notify",
-        {
-            "set_tweak": "sound",
-            "value": "default"
-        },
-        {
-            "set_tweak": "highlight"
-        }
-    ]
-}
-```
-
 ##### Default Underride Rules
 
 **`.m.rule.call`**

data/api/client-server/definitions/push_ruleset.yaml

@@ -34,24 +34,6 @@ properties:
     type: array
 type: object
 example: {
-  "content": [
-    {
-      "actions": [
-        "notify",
-        {
-          "set_tweak": "sound",
-          "value": "default"
-        },
-        {
-          "set_tweak": "highlight"
-        }
-      ],
-      "default": true,
-      "enabled": true,
-      "pattern": "alice",
-      "rule_id": ".m.rule.contains_user_name"
-    }
-  ],
   "override": [
     {
       "actions": [],
@@ -113,12 +95,14 @@ example: {
       ],
       "conditions": [
         {
-          "kind": "contains_display_name"
+            "kind": "event_property_contains",
+            "key": "content.m\\.mentions.user_ids",
+            "value": "@alice:example.com"
         }
       ],
       "default": true,
       "enabled": true,
-      "rule_id": ".m.rule.contains_display_name"
+      "rule_id": ".m.rule.is_user_mention"
     },
     {
       "actions": [

data/event-schemas/examples/m.push_rules.yaml

@@ -3,24 +3,6 @@
   "type": "m.push_rules",
   "content": {
     "global": {
-      "content": [
-        {
-          "actions": [
-            "notify",
-            {
-              "set_tweak": "sound",
-              "value": "default"
-            },
-            {
-              "set_tweak": "highlight"
-            }
-          ],
-          "default": true,
-          "enabled": true,
-          "pattern": "alice",
-          "rule_id": ".m.rule.contains_user_name"
-        }
-      ],
       "override": [
         {
           "actions": [],
@@ -82,12 +64,14 @@
           ],
           "conditions": [
             {
-              "kind": "contains_display_name"
+                "kind": "event_property_contains",
+                "key": "content.m\\.mentions.user_ids",
+                "value": "@alice:example.com"
             }
           ],
           "default": true,
           "enabled": true,
-          "rule_id": ".m.rule.contains_display_name"
+          "rule_id": ".m.rule.is_user_mention"
         },
         {
           "actions": [