From 723fd495dde835d078b9f2074b6b62c06dea4575 Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Mon, 15 Aug 2022 10:19:47 +0100
Subject: [PATCH] Fix parsing of `"events_default"` level in
 `m.room.power_levels` events

---
 eventauth_test.go | 59 +++++++++++++++++++++++++++++++++++++++++++++++
 eventcontent.go   |  2 +-
 2 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/eventauth_test.go b/eventauth_test.go
index baf8d772..63532d3f 100644
--- a/eventauth_test.go
+++ b/eventauth_test.go
@@ -1137,3 +1137,62 @@ func newMemberContent(
 		ThirdPartyInvite: thirdPartyInvite,
 	}
 }
+
+var negativePowerLevelTestRoom = &testAuthEvents{
+	CreateJSON: json.RawMessage(`{
+		"type": "m.room.create",
+		"state_key": "",
+		"sender": "@u1:a",
+		"room_id": "!r1:a",
+		"event_id": "$e1:a",
+		"content": {
+			"room_version": "10"
+		}
+	}`),
+	PowerLevelsJSON: json.RawMessage(`{
+		"type": "m.room.power_levels",
+		"state_key": "",
+		"sender": "@u1:a",
+		"room_id": "!r1:a",
+		"event_id": "$e3:a",
+		"content": {
+			"events_default": -9007199254740990,
+			"state_default": -9007199254740990,
+			"users_default": -9007199254740990,
+			"users": {
+			}
+		}
+	}`),
+	MemberJSON: map[string]json.RawMessage{
+		"@u1:a": json.RawMessage(`{
+			"type": "m.room.member",
+			"state_key": "@u1:a",
+			"sender": "@u1:a",
+			"room_id": "!r1:a",
+			"event_id": "$e2:a",
+			"content": {
+				"membership": "join"
+			}
+		}`),
+	},
+}
+
+func TestNegativePowerLevels(t *testing.T) {
+	// User should be able to demote the user default level
+	// below their own effective level.
+	eventShouldSucceed, err := NewEventFromTrustedJSON(RawJSON(`{
+		"type": "m.room.message",
+		"sender": "@u1:a",
+		"room_id": "!r1:a",
+		"event_id": "$e5:a",
+		"content": {
+			"stuff": "i am a message event"
+		}
+	}`), false, RoomVersionV1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err = Allowed(eventShouldSucceed, negativePowerLevelTestRoom); err != nil {
+		t.Error("TestNegativePowerLevels should have succeeded but it didn't:", err)
+	}
+}
diff --git a/eventcontent.go b/eventcontent.go
index 5f9ba635..2fba9994 100644
--- a/eventcontent.go
+++ b/eventcontent.go
@@ -431,7 +431,7 @@ func NewPowerLevelContentFromEvent(event *Event) (c PowerLevelContent, err error
 			UsersDefaultLevel  levelJSONValue            `json:"users_default"`
 			EventLevels        map[string]levelJSONValue `json:"events"`
 			StateDefaultLevel  levelJSONValue            `json:"state_default"`
-			EventDefaultLevel  levelJSONValue            `json:"event_default"`
+			EventDefaultLevel  levelJSONValue            `json:"events_default"`
 			NotificationLevels map[string]levelJSONValue `json:"notifications"`
 		}
 		if err = json.Unmarshal(event.Content(), &content); err != nil {