Support the backwards compatibility features in MSC3952.

changelog.d/14958.feature

@@ -0,0 +1 @@
+Experimental support for [MSC3952](https://github.com/matrix-org/matrix-spec-proposals/pull/3952): intentional mentions.

rust/benches/evaluator.rs

@@ -33,6 +33,7 @@ fn bench_match_exact(b: &mut Bencher) {
 
     let eval = PushRuleEvaluator::py_new(
         flattened_keys,
+        false,
         BTreeSet::new(),
         false,
         10,
@@ -71,6 +72,7 @@ fn bench_match_word(b: &mut Bencher) {
 
     let eval = PushRuleEvaluator::py_new(
         flattened_keys,
+        false,
         BTreeSet::new(),
         false,
         10,
@@ -109,6 +111,7 @@ fn bench_match_word_miss(b: &mut Bencher) {
 
     let eval = PushRuleEvaluator::py_new(
         flattened_keys,
+        false,
         BTreeSet::new(),
         false,
         10,
@@ -147,6 +150,7 @@ fn bench_eval_message(b: &mut Bencher) {
 
     let eval = PushRuleEvaluator::py_new(
         flattened_keys,
+        false,
         BTreeSet::new(),
         false,
         10,

rust/src/push/evaluator.rs

@@ -68,6 +68,8 @@ pub struct PushRuleEvaluator {
     /// The "content.body", if any.
     body: String,
 
+    /// True if the event has a messages property and MSC3952 support is enabled.
+    has_mentions: bool,
     /// The user mentions that were part of the message.
     user_mentions: BTreeSet<String>,
     /// True if the message is a room message.
@@ -105,6 +107,7 @@ impl PushRuleEvaluator {
     #[new]
     pub fn py_new(
         flattened_keys: BTreeMap<String, String>,
+        has_mentions: bool,
         user_mentions: BTreeSet<String>,
         room_mention: bool,
         room_member_count: u64,
@@ -123,6 +126,7 @@ impl PushRuleEvaluator {
         Ok(PushRuleEvaluator {
             flattened_keys,
             body,
+            has_mentions,
             user_mentions,
             room_mention,
             room_member_count,
@@ -155,6 +159,18 @@ impl PushRuleEvaluator {
             }
 
             let rule_id = &push_rule.rule_id().to_string();
+
+            // For backwards-compatibility the legacy mention rules are disabled
+            // only if the event contains the 'm.mentions' property (and if the
+            // experimental feature is enabled, we check that in the Python code).
+            if self.has_mentions
+                && (rule_id == ".m.rule.contains_display_name"
+                    || rule_id == ".m.rule.contains_user_name"
+                    || rule_id == ".m.rule.roomnotif")
+            {
+                continue;
+            }
+
             let extev_flag = &RoomVersionFeatures::ExtensibleEvents.as_str().to_string();
             let supports_extensible_events = self.room_version_feature_flags.contains(extev_flag);
             let safe_from_rver_condition = SAFE_EXTENSIBLE_EVENTS_RULE_IDS.contains(rule_id);
@@ -441,6 +457,7 @@ fn push_rule_evaluator() {
     flattened_keys.insert("content.body".to_string(), "foo bar bob hello".to_string());
     let evaluator = PushRuleEvaluator::py_new(
         flattened_keys,
+        false,
         BTreeSet::new(),
         false,
         10,
@@ -468,6 +485,7 @@ fn test_requires_room_version_supports_condition() {
     let flags = vec![RoomVersionFeatures::ExtensibleEvents.as_str().to_string()];
     let evaluator = PushRuleEvaluator::py_new(
         flattened_keys,
+        false,
         BTreeSet::new(),
         false,
         10,

stubs/synapse/synapse_rust/push.pyi

@@ -56,6 +56,7 @@ class PushRuleEvaluator:
     def __init__(
         self,
         flattened_keys: Mapping[str, str],
+        has_mentions: bool,
         user_mentions: Set[str],
         room_mention: bool,
         room_member_count: int,

synapse/push/bulk_push_rule_evaluator.py

@@ -119,6 +119,9 @@ def __init__(self, hs: "HomeServer"):
         self.should_calculate_push_rules = self.hs.config.push.enable_push
 
         self._related_event_match_enabled = self.hs.config.experimental.msc3664_enabled
+        self._intentional_mentions_enabled = (
+            self.hs.config.experimental.msc3952_intentional_mentions
+        )
 
         self.room_push_rule_cache_metrics = register_cache(
             "cache",
@@ -364,9 +367,11 @@ async def _action_for_event_by_user(
 
         # Pull out any user and room mentions.
         mentions = event.content.get(EventContentFields.MSC3952_MENTIONS)
+        has_mentions = self._intentional_mentions_enabled and isinstance(mentions, dict)
         user_mentions: Set[str] = set()
         room_mention = False
-        if isinstance(mentions, dict):
+        if has_mentions:
+            assert isinstance(mentions, dict)
             # Remove out any non-string items and convert to a set.
             user_mentions_raw = mentions.get("user_ids")
             if isinstance(user_mentions_raw, list):
@@ -378,6 +383,7 @@ async def _action_for_event_by_user(
 
         evaluator = PushRuleEvaluator(
             _flatten_dict(event, room_version=event.room_version),
+            has_mentions,
             user_mentions,
             room_mention,
             room_member_count,

tests/push/test_push_rule_evaluator.py

@@ -42,6 +42,7 @@ def _get_evaluator(
         self,
         content: JsonMapping,
         *,
+        has_mentions: bool = False,
         user_mentions: Optional[Set[str]] = None,
         room_mention: bool = False,
         related_events: Optional[JsonDict] = None,
@@ -62,6 +63,7 @@ def _get_evaluator(
         power_levels: Dict[str, Union[int, Dict[str, int]]] = {}
         return PushRuleEvaluator(
             _flatten_dict(event),
+            has_mentions,
             user_mentions or set(),
             room_mention,
             room_member_count,
@@ -102,19 +104,21 @@ def test_user_mentions(self) -> None:
         condition = {"kind": "org.matrix.msc3952.is_user_mention"}
 
         # No mentions shouldn't match.
-        evaluator = self._get_evaluator({})
+        evaluator = self._get_evaluator({}, has_mentions=True)
         self.assertFalse(evaluator.matches(condition, "@user:test", None))
 
         # An empty set shouldn't match
-        evaluator = self._get_evaluator({}, user_mentions=set())
+        evaluator = self._get_evaluator({}, has_mentions=True, user_mentions=set())
         self.assertFalse(evaluator.matches(condition, "@user:test", None))
 
         # The Matrix ID appearing anywhere in the mentions list should match
-        evaluator = self._get_evaluator({}, user_mentions={"@user:test"})
+        evaluator = self._get_evaluator(
+            {}, has_mentions=True, user_mentions={"@user:test"}
+        )
         self.assertTrue(evaluator.matches(condition, "@user:test", None))
 
         evaluator = self._get_evaluator(
-            {}, user_mentions={"@another:test", "@user:test"}
+            {}, has_mentions=True, user_mentions={"@another:test", "@user:test"}
         )
         self.assertTrue(evaluator.matches(condition, "@user:test", None))
 
@@ -126,16 +130,16 @@ def test_room_mentions(self) -> None:
         condition = {"kind": "org.matrix.msc3952.is_room_mention"}
 
         # No room mention shouldn't match.
-        evaluator = self._get_evaluator({})
+        evaluator = self._get_evaluator({}, has_mentions=True)
         self.assertFalse(evaluator.matches(condition, None, None))
 
         # Room mention should match.
-        evaluator = self._get_evaluator({}, room_mention=True)
+        evaluator = self._get_evaluator({}, has_mentions=True, room_mention=True)
         self.assertTrue(evaluator.matches(condition, None, None))
 
         # A room mention and user mention is valid.
         evaluator = self._get_evaluator(
-            {}, user_mentions={"@another:test"}, room_mention=True
+            {}, has_mentions=True, user_mentions={"@another:test"}, room_mention=True
         )
         self.assertTrue(evaluator.matches(condition, None, None))