v9.9.0-rc.1

Prepare changelog for v9.9.0-rc.1
Merge pull request #1638 from matrix-org/jryans/rm-olm-profiling
2021-03-10 17:21:50 +00:00 · 2021-03-10 17:21:49 +00:00 · 2021-03-10 12:44:22 +00:00 · 2021-03-10 12:43:45 +00:00 · 2021-03-10 12:43:45 +00:00 · 2021-03-10 11:25:44 +00:00
34 changed files with 1937 additions and 792 deletions
@@ -35,6 +35,8 @@ module.exports = {
        "files": ["src/**/*.ts"],
        "extends": ["matrix-org/ts"],
        "rules": {
+            // We're okay being explicit at the moment
+            "@typescript-eslint/no-empty-interface": "off",
            // While we're converting to ts we make heavy use of this
            "@typescript-eslint/no-explicit-any": "off",
            "quotes": "off",
@@ -1,3 +1,153 @@
+Changes in [9.9.0-rc.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v9.9.0-rc.1) (2021-03-10)
+==========================================================================================================
+[Full Changelog](https://github.com/matrix-org/matrix-js-sdk/compare/v9.8.0...v9.9.0-rc.1)
+
+ * Remove detailed Olm session logging
+   [\#1638](https://github.com/matrix-org/matrix-js-sdk/pull/1638)
+ * Add space summary suggested only param
+   [\#1637](https://github.com/matrix-org/matrix-js-sdk/pull/1637)
+ * Check TURN servers periodically, and at start of calls
+   [\#1634](https://github.com/matrix-org/matrix-js-sdk/pull/1634)
+ * Support sending invite reasons
+   [\#1624](https://github.com/matrix-org/matrix-js-sdk/pull/1624)
+ * Bump elliptic from 6.5.3 to 6.5.4
+   [\#1636](https://github.com/matrix-org/matrix-js-sdk/pull/1636)
+ * Add a function to get a room's MXC URI
+   [\#1635](https://github.com/matrix-org/matrix-js-sdk/pull/1635)
+ * Stop streams if the call has ended
+   [\#1633](https://github.com/matrix-org/matrix-js-sdk/pull/1633)
+ * Remove export keyword from global.d.ts
+   [\#1631](https://github.com/matrix-org/matrix-js-sdk/pull/1631)
+ * Fix IndexedDB store creation example
+   [\#1445](https://github.com/matrix-org/matrix-js-sdk/pull/1445)
+ * An attempt to  cleanup how constraints are handled in calls
+   [\#1613](https://github.com/matrix-org/matrix-js-sdk/pull/1613)
+ * Extract display name patterns to constants
+   [\#1628](https://github.com/matrix-org/matrix-js-sdk/pull/1628)
+ * Bump pug-code-gen from 2.0.2 to 2.0.3
+   [\#1630](https://github.com/matrix-org/matrix-js-sdk/pull/1630)
+ * Avoid deadlocks when ensuring Olm sessions for devices
+   [\#1627](https://github.com/matrix-org/matrix-js-sdk/pull/1627)
+ * Filter out edits from other senders in history
+   [\#1626](https://github.com/matrix-org/matrix-js-sdk/pull/1626)
+ * Fix ContentHelpers export
+   [\#1618](https://github.com/matrix-org/matrix-js-sdk/pull/1618)
+ * Add logging to in progress Olm sessions
+   [\#1621](https://github.com/matrix-org/matrix-js-sdk/pull/1621)
+ * Don't ignore ICE candidates received before offer/answer
+   [\#1623](https://github.com/matrix-org/matrix-js-sdk/pull/1623)
+ * Better handling of send failures on VoIP events
+   [\#1622](https://github.com/matrix-org/matrix-js-sdk/pull/1622)
+ * Log when turn creds expire
+   [\#1620](https://github.com/matrix-org/matrix-js-sdk/pull/1620)
+ * Initial Spaces [MSC1772] support
+   [\#1563](https://github.com/matrix-org/matrix-js-sdk/pull/1563)
+ * Add logging to crypto store transactions
+   [\#1617](https://github.com/matrix-org/matrix-js-sdk/pull/1617)
+ * Room helper for getting type and checking if it is a space room
+   [\#1610](https://github.com/matrix-org/matrix-js-sdk/pull/1610)
+
+Changes in [9.8.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v9.8.0) (2021-03-01)
+================================================================================================
+[Full Changelog](https://github.com/matrix-org/matrix-js-sdk/compare/v9.8.0-rc.1...v9.8.0)
+
+ * No changes since rc.1
+
+Changes in [9.8.0-rc.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v9.8.0-rc.1) (2021-02-24)
+==========================================================================================================
+[Full Changelog](https://github.com/matrix-org/matrix-js-sdk/compare/v9.7.0...v9.8.0-rc.1)
+
+ * Optimise prefixed logger
+   [\#1615](https://github.com/matrix-org/matrix-js-sdk/pull/1615)
+ * Add debug logs to encryption prep, take 3
+   [\#1614](https://github.com/matrix-org/matrix-js-sdk/pull/1614)
+ * Add functions for upper & lowercase random strings
+   [\#1612](https://github.com/matrix-org/matrix-js-sdk/pull/1612)
+ * Room helpers for invite permissions and join rules
+   [\#1609](https://github.com/matrix-org/matrix-js-sdk/pull/1609)
+ * Fixed wording in "Adding video track with id" log
+   [\#1606](https://github.com/matrix-org/matrix-js-sdk/pull/1606)
+ * Add more debug logs to encryption prep
+   [\#1605](https://github.com/matrix-org/matrix-js-sdk/pull/1605)
+ * Add option to set ice candidate pool size
+   [\#1604](https://github.com/matrix-org/matrix-js-sdk/pull/1604)
+ * Cancel call if no source was selected
+   [\#1601](https://github.com/matrix-org/matrix-js-sdk/pull/1601)
+
+Changes in [9.7.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v9.7.0) (2021-02-16)
+================================================================================================
+[Full Changelog](https://github.com/matrix-org/matrix-js-sdk/compare/v9.7.0-rc.1...v9.7.0)
+
+ * No changes since rc.1
+
+Changes in [9.7.0-rc.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v9.7.0-rc.1) (2021-02-10)
+==========================================================================================================
+[Full Changelog](https://github.com/matrix-org/matrix-js-sdk/compare/v9.6.0...v9.7.0-rc.1)
+
+ * Handle undefined peerconn
+   [\#1600](https://github.com/matrix-org/matrix-js-sdk/pull/1600)
+ * ReEmitter: Don't throw if no error handler is attached
+   [\#1599](https://github.com/matrix-org/matrix-js-sdk/pull/1599)
+ * Convert ReEmitter to TS
+   [\#1598](https://github.com/matrix-org/matrix-js-sdk/pull/1598)
+ * Fix typo in main readme
+   [\#1597](https://github.com/matrix-org/matrix-js-sdk/pull/1597)
+ * Remove rogue plus character
+   [\#1596](https://github.com/matrix-org/matrix-js-sdk/pull/1596)
+ * Fix call ID NaN
+   [\#1595](https://github.com/matrix-org/matrix-js-sdk/pull/1595)
+ * Fix Electron type merging
+   [\#1594](https://github.com/matrix-org/matrix-js-sdk/pull/1594)
+ * Fix browser screen share
+   [\#1593](https://github.com/matrix-org/matrix-js-sdk/pull/1593)
+ * Fix desktop Matrix screen sharing
+   [\#1570](https://github.com/matrix-org/matrix-js-sdk/pull/1570)
+ * Guard against confused server retry times
+   [\#1591](https://github.com/matrix-org/matrix-js-sdk/pull/1591)
+ * Decrypt redaction events
+   [\#1589](https://github.com/matrix-org/matrix-js-sdk/pull/1589)
+ * Fix edge cases with peeking where a room is re-peeked
+   [\#1587](https://github.com/matrix-org/matrix-js-sdk/pull/1587)
+
+Changes in [9.6.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v9.6.0) (2021-02-03)
+================================================================================================
+[Full Changelog](https://github.com/matrix-org/matrix-js-sdk/compare/v9.6.0-rc.1...v9.6.0)
+
+ * [Release] Fix edge cases with peeking where a room is re-peeked
+   [\#1588](https://github.com/matrix-org/matrix-js-sdk/pull/1588)
+
+Changes in [9.6.0-rc.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v9.6.0-rc.1) (2021-01-29)
+==========================================================================================================
+[Full Changelog](https://github.com/matrix-org/matrix-js-sdk/compare/v9.5.1...v9.6.0-rc.1)
+
+ * Add support for getting call stats
+   [\#1584](https://github.com/matrix-org/matrix-js-sdk/pull/1584)
+ * Fix compatibility with v0 calls
+   [\#1583](https://github.com/matrix-org/matrix-js-sdk/pull/1583)
+ * Upgrade deps 2021-01
+   [\#1582](https://github.com/matrix-org/matrix-js-sdk/pull/1582)
+ * Log the call ID when logging that we've received VoIP events
+   [\#1581](https://github.com/matrix-org/matrix-js-sdk/pull/1581)
+ * Fix extra negotiate message in Firefox
+   [\#1579](https://github.com/matrix-org/matrix-js-sdk/pull/1579)
+ * Add debug logs to encryption prep
+   [\#1580](https://github.com/matrix-org/matrix-js-sdk/pull/1580)
+ * Expose getPresence endpoint
+   [\#1578](https://github.com/matrix-org/matrix-js-sdk/pull/1578)
+ * Queue keys for backup even if backup isn't enabled yet
+   [\#1577](https://github.com/matrix-org/matrix-js-sdk/pull/1577)
+ * Stop retrying TURN access when forbidden
+   [\#1576](https://github.com/matrix-org/matrix-js-sdk/pull/1576)
+ * Add DTMF sending support
+   [\#1573](https://github.com/matrix-org/matrix-js-sdk/pull/1573)
+
+Changes in [9.5.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v9.5.1) (2021-01-26)
+================================================================================================
+[Full Changelog](https://github.com/matrix-org/matrix-js-sdk/compare/v9.5.0...v9.5.1)
+
+ * [Release] Fix compatibility with v0 calls
+   [\#1585](https://github.com/matrix-org/matrix-js-sdk/pull/1585)
+
 Changes in [9.5.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v9.5.0) (2021-01-18)
 ================================================================================================
 [Full Changelog](https://github.com/matrix-org/matrix-js-sdk/compare/v9.5.0-rc.1...v9.5.0)
@@ -307,7 +307,7 @@ The SDK supports end-to-end encryption via the Olm and Megolm protocols, using
 [libolm](https://gitlab.matrix.org/matrix-org/olm). It is left up to the
 application to make libolm available, via the ``Olm`` global.

-It is also necessry to call ``matrixClient.initCrypto()`` after creating a new
+It is also necessary to call ``matrixClient.initCrypto()`` after creating a new
 ``MatrixClient`` (but **before** calling ``matrixClient.startClient()``) to
 initialise the crypto layer.

@@ -1,6 +1,6 @@
 {
  "name": "matrix-js-sdk",
-  "version": "9.5.0",
+  "version": "9.9.0-rc.1",
  "description": "Matrix Client-Server SDK for Javascript",
  "scripts": {
    "prepublishOnly": "yarn build",
@@ -15,7 +15,7 @@
    "build:minify-browser": "terser dist/browser-matrix.js --compress --mangle --source-map --output dist/browser-matrix.min.js",
    "gendoc": "jsdoc -c jsdoc.json -P package.json",
    "lint": "yarn lint:types && yarn lint:js",
-    "lint:js": "eslint --max-warnings 73 src spec",
+    "lint:js": "eslint --max-warnings 72 src spec",
    "lint:types": "tsc --noEmit",
    "test": "jest spec/ --coverage --testEnvironment node",
    "test:watch": "jest spec/ --coverage --testEnvironment node --watch"
@@ -54,22 +54,22 @@
    "bs58": "^4.0.1",
    "content-type": "^1.0.4",
    "loglevel": "^1.7.1",
-    "qs": "^6.9.4",
+    "qs": "^6.9.6",
    "request": "^2.88.2",
    "unhomoglyph": "^1.0.6"
  },
  "devDependencies": {
-    "@babel/cli": "^7.12.8",
-    "@babel/core": "^7.12.9",
+    "@babel/cli": "^7.12.10",
+    "@babel/core": "^7.12.10",
    "@babel/plugin-proposal-class-properties": "^7.12.1",
    "@babel/plugin-proposal-numeric-separator": "^7.12.7",
    "@babel/plugin-proposal-object-rest-spread": "^7.12.1",
    "@babel/plugin-syntax-dynamic-import": "^7.8.3",
-    "@babel/plugin-transform-runtime": "^7.12.1",
-    "@babel/preset-env": "^7.12.7",
+    "@babel/plugin-transform-runtime": "^7.12.10",
+    "@babel/preset-env": "^7.12.11",
    "@babel/preset-typescript": "^7.12.7",
-    "@babel/register": "^7.12.1",
-    "@types/jest": "^26.0.15",
+    "@babel/register": "^7.12.10",
+    "@types/jest": "^26.0.20",
    "@types/node": "12",
    "@types/request": "^2.48.5",
    "babel-eslint": "^10.1.0",
@@ -78,20 +78,20 @@
    "better-docs": "^2.3.2",
    "browserify": "^17.0.0",
    "docdash": "^1.2.0",
-    "eslint": "7.14.0",
-    "eslint-config-matrix-org": "^0.1.2",
+    "eslint": "7.18.0",
+    "eslint-config-matrix-org": "^0.2.0",
    "eslint-plugin-babel": "^5.3.1",
    "exorcist": "^1.0.1",
    "fake-indexeddb": "^3.1.2",
    "jest": "^26.6.3",
-    "jest-localstorage-mock": "^2.4.3",
+    "jest-localstorage-mock": "^2.4.6",
    "jsdoc": "^3.6.6",
    "matrix-mock-request": "^1.2.3",
    "olm": "https://packages.matrix.org/npm/olm/olm-3.2.1.tgz",
    "rimraf": "^3.0.2",
-    "terser": "^5.5.0",
+    "terser": "^5.5.1",
    "tsify": "^5.0.2",
-    "typescript": "^4.1.2"
+    "typescript": "^4.1.3"
  },
  "jest": {
    "testEnvironment": "node"
@@ -0,0 +1,72 @@
+/*
+Copyright 2021 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { EventEmitter } from "events";
+import { ReEmitter } from "../../src/ReEmitter";
+
+const EVENTNAME = "UnknownEntry";
+
+class EventSource extends EventEmitter {
+    doTheThing() {
+        this.emit(EVENTNAME, "foo", "bar");
+    }
+
+    doAnError() {
+        this.emit('error');
+    }
+}
+
+class EventTarget extends EventEmitter {
+
+}
+
+describe("ReEmitter", function() {
+    it("Re-Emits events with the same args", function() {
+        const src = new EventSource();
+        const tgt = new EventTarget();
+
+        const handler = jest.fn();
+        tgt.on(EVENTNAME, handler);
+
+        const reEmitter = new ReEmitter(tgt);
+        reEmitter.reEmit(src, [EVENTNAME]);
+
+        src.doTheThing();
+
+        // Args should be the args passed to 'emit' after the event name, and
+        // also the source object of the event which re-emitter adds
+        expect(handler).toHaveBeenCalledWith("foo", "bar", src);
+    });
+
+    it("Doesn't throw if no handler for 'error' event", function() {
+        const src = new EventSource();
+        const tgt = new EventTarget();
+
+        const reEmitter = new ReEmitter(tgt);
+        reEmitter.reEmit(src, ['error']);
+
+        // without the workaround in ReEmitter, this would throw
+        src.doAnError();
+
+        const handler = jest.fn();
+        tgt.on('error', handler);
+
+        src.doAnError();
+
+        // Now we've attached an error handler, it should be called
+        expect(handler).toHaveBeenCalled();
+    });
+});
@@ -190,5 +190,91 @@ describe("OlmDevice", function() {
            // new session and will have called claimOneTimeKeys
            expect(count).toBe(2);
        });
+
+        it("avoids deadlocks when two tasks are ensuring the same devices", async function() {
+            // This test checks whether `ensureOlmSessionsForDevices` properly
+            // handles multiple tasks in flight ensuring some set of devices in
+            // common without deadlocks.
+
+            let claimRequestCount = 0;
+            const baseApis = {
+                claimOneTimeKeys: () => {
+                    // simulate a very slow server (.5 seconds to respond)
+                    claimRequestCount++;
+                    return new Promise((resolve, reject) => {
+                        setTimeout(reject, 500);
+                    });
+                },
+            };
+
+            const deviceBobA = DeviceInfo.fromStorage({
+                keys: {
+                    "curve25519:BOB-A": "akey",
+                },
+            }, "BOB-A");
+            const deviceBobB = DeviceInfo.fromStorage({
+                keys: {
+                    "curve25519:BOB-B": "bkey",
+                },
+            }, "BOB-B");
+
+            // There's no required ordering of devices per user, so here we
+            // create two different orderings so that each task reserves a
+            // device the other task needs before continuing.
+            const devicesByUserAB = {
+                "@bob:example.com": [
+                    deviceBobA,
+                    deviceBobB,
+                ],
+            };
+            const devicesByUserBA = {
+                "@bob:example.com": [
+                    deviceBobB,
+                    deviceBobA,
+                ],
+            };
+
+            function alwaysSucceed(promise) {
+                // swallow any exception thrown by a promise, so that
+                // Promise.all doesn't abort
+                return promise.catch(() => {});
+            }
+
+            const task1 = alwaysSucceed(olmlib.ensureOlmSessionsForDevices(
+                aliceOlmDevice, baseApis, devicesByUserAB,
+            ));
+
+            // After a single tick through the first task, it should have
+            // claimed ownership of all devices to avoid deadlocking others.
+            expect(Object.keys(aliceOlmDevice._sessionsInProgress).length).toBe(2);
+
+            const task2 = alwaysSucceed(olmlib.ensureOlmSessionsForDevices(
+                aliceOlmDevice, baseApis, devicesByUserBA,
+            ));
+
+            // The second task should not have changed the ownership count, as
+            // it's waiting on the first task.
+            expect(Object.keys(aliceOlmDevice._sessionsInProgress).length).toBe(2);
+
+            // Track the tasks, but don't await them yet.
+            const promises = Promise.all([
+                task1,
+                task2,
+            ]);
+
+            await new Promise((resolve) => {
+                setTimeout(resolve, 200);
+            });
+
+            // After .2s, the first task should have made an initial claim request.
+            expect(claimRequestCount).toBe(1);
+
+            await promises;
+
+            // After waiting for both tasks to complete, the first task should
+            // have failed, so the second task should have tried to create a
+            // new session and will have called claimOneTimeKeys
+            expect(claimRequestCount).toBe(2);
+        });
    });
 });
@@ -521,4 +521,19 @@ describe("MatrixClient", function() {
        xit("should be able to peek into a room using peekInRoom", function(done) {
        });
    });
+
+    describe("getPresence", function() {
+        it("should send a presence HTTP GET", function() {
+            httpLookups = [{
+                method: "GET",
+                path: `/presence/${encodeURIComponent(userId)}/status`,
+                data: {
+                    "presence": "unavailable",
+                    "last_active_ago": 420845,
+                },
+            }];
+            client.getPresence(userId);
+            expect(httpLookups.length).toEqual(0);
+        });
+    });
 });
@@ -79,6 +79,7 @@ class MockRTCPeerConnection {
        return Promise.resolve();
    }
    close() {}
+    getStats() { return []; }
 }

 describe('Call', function() {
@@ -122,6 +123,7 @@ describe('Call', function() {
        // We just stub out sendEvent: we're not interested in testing the client's
        // event sending code here
        client.client.sendEvent = () => {};
+        client.httpBackend.when("GET", "/voip/turnServer").respond(200, {});
        call = new MatrixCall({
            client: client.client,
            roomId: '!foo:bar',
@@ -138,7 +140,9 @@ describe('Call', function() {
    });

    it('should ignore candidate events from non-matching party ID', async function() {
-        await call.placeVoiceCall();
+        const callPromise = call.placeVoiceCall();
+        await client.httpBackend.flush();
+        await callPromise;
        await call.onAnswerReceived({
            getContent: () => {
                return {
@@ -190,4 +194,64 @@ describe('Call', function() {
        // Hangup to stop timers
        call.hangup(CallErrorCode.UserHangup, true);
    });
+
+    it('should add candidates received before answer if party ID is correct', async function() {
+        const callPromise = call.placeVoiceCall();
+        await client.httpBackend.flush();
+        await callPromise;
+        call.peerConn.addIceCandidate = jest.fn();
+
+        call.onRemoteIceCandidatesReceived({
+            getContent: () => {
+                return {
+                    version: 1,
+                    call_id: call.callId,
+                    party_id: 'the_correct_party_id',
+                    candidates: [
+                        {
+                            candidate: 'the_correct_candidate',
+                            sdpMid: '',
+                        },
+                    ],
+                };
+            },
+        });
+
+        call.onRemoteIceCandidatesReceived({
+            getContent: () => {
+                return {
+                    version: 1,
+                    call_id: call.callId,
+                    party_id: 'some_other_party_id',
+                    candidates: [
+                        {
+                            candidate: 'the_wrong_candidate',
+                            sdpMid: '',
+                        },
+                    ],
+                };
+            },
+        });
+
+        expect(call.peerConn.addIceCandidate.mock.calls.length).toBe(0);
+
+        await call.onAnswerReceived({
+            getContent: () => {
+                return {
+                    version: 1,
+                    call_id: call.callId,
+                    party_id: 'the_correct_party_id',
+                    answer: {
+                        sdp: DUMMY_SDP,
+                    },
+                };
+            },
+        });
+
+        expect(call.peerConn.addIceCandidate.mock.calls.length).toBe(1);
+        expect(call.peerConn.addIceCandidate).toHaveBeenCalledWith({
+            candidate: 'the_correct_candidate',
+            sdpMid: '',
+        });
+    });
 });
@@ -36,6 +36,10 @@ export enum EventType {
     */
    RoomAliases = "m.room.aliases", // deprecated https://matrix.org/docs/spec/client_server/r0.6.1#historical-events

+    // Spaces MSC1772
+    SpaceChild = "org.matrix.msc1772.space.child",
+    SpaceParent = "org.matrix.msc1772.space.parent",
+
    // Room timeline events
    RoomRedaction = "m.room.redaction",
    RoomMessage = "m.room.message",
@@ -87,3 +91,9 @@ export enum MsgType {
    Location = "m.location",
    Video = "m.video",
 }
+
+export const RoomCreateTypeField = "org.matrix.msc1772.type"; // Spaces MSC1772
+
+export enum RoomType {
+    Space = "org.matrix.msc1772.space", // Spaces MSC1772
+}
@@ -26,10 +26,49 @@ declare global {
        }
    }

+    interface Window {
+        electron?: Electron;
+    }
+
+    interface Electron {
+        getDesktopCapturerSources(options: GetSourcesOptions): Promise<Array<DesktopCapturerSource>>;
+    }
+
    interface MediaDevices {
        // This is experimental and types don't know about it yet
        // https://github.com/microsoft/TypeScript/issues/33232
-        getDisplayMedia(constraints: MediaStreamConstraints): Promise<MediaStream>;
+        getDisplayMedia(constraints: MediaStreamConstraints | DesktopCapturerConstraints): Promise<MediaStream>;
+        getUserMedia(constraints: MediaStreamConstraints | DesktopCapturerConstraints): Promise<MediaStream>;
+    }
+
+    interface DesktopCapturerConstraints {
+        audio: boolean | {
+            mandatory: {
+                chromeMediaSource: string;
+                chromeMediaSourceId: string;
+            };
+        };
+        video: boolean | {
+            mandatory: {
+                chromeMediaSource: string;
+                chromeMediaSourceId: string;
+            };
+        };
+    }
+
+    interface DesktopCapturerSource {
+        id: string;
+        name: string;
+        thumbnailURL: string;
+    }
+
+    interface GetSourcesOptions {
+        types: Array<string>;
+        thumbnailSize?: {
+            height: number;
+            width: number;
+        };
+        fetchWindowIcons?: boolean;
    }

    interface HTMLAudioElement {
@@ -1,52 +0,0 @@
-/*
-Copyright 2015, 2016 OpenMarket Ltd
-Copyright 2017 Vector Creations Ltd
-Copyright 2017 New Vector Ltd
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-/**
- * @module
- */
-
-export class ReEmitter {
-    constructor(target) {
-        this.target = target;
-
-        // We keep one bound event handler for each event name so we know
-        // what event is arriving
-        this.boundHandlers = {};
-    }
-
-    _handleEvent(eventName, ...args) {
-        this.target.emit(eventName, ...args);
-    }
-
-    reEmit(source, eventNames) {
-        // We include the source as the last argument for event handlers which may need it,
-        // such as read receipt listeners on the client class which won't have the context
-        // of the room.
-        const forSource = (handler, ...args) => {
-            handler(...args, source);
-        };
-        for (const eventName of eventNames) {
-            if (this.boundHandlers[eventName] === undefined) {
-                this.boundHandlers[eventName] = this._handleEvent.bind(this, eventName);
-            }
-
-            const boundHandler = forSource.bind(this, this.boundHandlers[eventName]);
-            source.on(eventName, boundHandler);
-        }
-    }
-}
@@ -0,0 +1,50 @@
+/*
+Copyright 2015, 2016 OpenMarket Ltd
+Copyright 2017 Vector Creations Ltd
+Copyright 2017 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { EventEmitter } from "events";
+
+export class ReEmitter {
+    private target: EventEmitter;
+
+    constructor(target: EventEmitter) {
+        this.target = target;
+    }
+
+    reEmit(source: EventEmitter, eventNames: string[]) {
+        for (const eventName of eventNames) {
+            // We include the source as the last argument for event handlers which may need it,
+            // such as read receipt listeners on the client class which won't have the context
+            // of the room.
+            const forSource = (...args) => {
+                // EventEmitter special cases 'error' to make the emit function throw if no
+                // handler is attached, which sort of makes sense for making sure that something
+                // handles an error, but for re-emitting, there could be a listener on the original
+                // source object so the test doesn't really work. We *could* try to replicate the
+                // same logic and throw if there is no listener on either the source or the target,
+                // but this behaviour is fairly undesireable for us anyway: the main place we throw
+                // 'error' events is for calls, where error events are usually emitted some time
+                // later by a different part of the code where 'emit' throwing because the app hasn't
+                // added an error handler isn't terribly helpful. (A better fix in retrospect may
+                // have been to just avoid using the event name 'error', but backwards compat...)
+                if (eventName === 'error' && this.target.listenerCount('error') === 0) return;
+                this.target.emit(eventName, ...args, source);
+            };
+            source.on(eventName, forSource);
+        }
+    }
+}
@@ -2374,3 +2374,35 @@ MatrixBaseApis.prototype.reportEvent = function(roomId, eventId, score, reason)
    return this._http.authedRequest(undefined, "POST", path, null, {score, reason});
 };

+/**
+ * Fetches or paginates a summary of a space as defined by MSC2946
+ * @param {string} roomId The ID of the space-room to use as the root of the summary.
+ * @param {number?} maxRoomsPerSpace The maximum number of rooms to return per subspace.
+ * @param {boolean?} suggestedOnly Whether to only return rooms with suggested=true.
+ * @param {boolean?} autoJoinOnly Whether to only return rooms with auto_join=true.
+ * @param {number?} limit The maximum number of rooms to return in total.
+ * @param {string?} batch The opaque token to paginate a previous summary request.
+ * @returns {Promise} the response, with next_batch, rooms, events fields.
+ */
+MatrixBaseApis.prototype.getSpaceSummary = function(
+    roomId,
+    maxRoomsPerSpace,
+    suggestedOnly,
+    autoJoinOnly,
+    limit,
+    batch,
+) {
+    const path = utils.encodeUri("/rooms/$roomId/spaces", {
+        $roomId: roomId,
+    });
+
+    return this._http.authedRequest(undefined, "POST", path, null, {
+        max_rooms_per_space: maxRoomsPerSpace,
+        suggested_only: suggestedOnly,
+        auto_join_only: autoJoinOnly,
+        limit,
+        batch,
+    }, {
+        prefix: "/_matrix/client/unstable/org.matrix.msc2946",
+    });
+};
@@ -61,6 +61,7 @@ import {DEHYDRATION_ALGORITHM} from "./crypto/dehydration";
 const SCROLLBACK_DELAY_MS = 3000;
 export const CRYPTO_ENABLED = isCryptoAvailable();
 const CAPABILITIES_CACHE_MS = 21600000; // 6 hours - an arbitrary value
+const TURN_CHECK_INTERVAL = 10 * 60 * 1000; // poll for turn credentials every 10 minutes

 function keysFromRecoverySession(sessions, decryptionKey, roomId) {
    const keys = [];
@@ -180,6 +181,11 @@ function keyFromRecoverySession(session, decryptionKey) {
 * @param {boolean} [opts.forceTURN]
 * Optional. Whether relaying calls through a TURN server should be forced.
 *
+ * * @param {boolean} [opts.iceCandidatePoolSize]
+ * Optional. Up to this many ICE candidates will be gathered when an incoming call arrives.
+ * Gathering does not send data to the caller, but will communicate with the configured TURN
+ * server. Default 0.
+ *
 * @param {boolean} [opts.supportsCallTransfer]
 * Optional. True to advertise support for call transfers to other parties on Matrix calls.
 *
@@ -367,6 +373,7 @@ export function MatrixClient(opts) {
    this._cryptoCallbacks = opts.cryptoCallbacks || {};

    this._forceTURN = opts.forceTURN || false;
+    this._iceCandidatePoolSize = opts.iceCandidatePoolSize === undefined ? 0 : opts.iceCandidatePoolSize;
    this._supportsCallTransfer = opts.supportsCallTransfer || false;
    this._fallbackICEServerAllowed = opts.fallbackICEServerAllowed || false;

@@ -387,6 +394,10 @@ export function MatrixClient(opts) {
    this._clientWellKnown = undefined;
    this._clientWellKnownPromise = undefined;

+    this._turnServers = [];
+    this._turnServersExpiry = 0;
+    this._checkTurnServersIntervalID = null;
+
    // The SDK doesn't really provide a clean way for events to recalculate the push
    // actions for themselves, so we have to kinda help them out when they are encrypted.
    // We do this so that push rules are correctly executed on events in their decrypted
@@ -3441,11 +3452,12 @@ MatrixClient.prototype.getRoomUpgradeHistory = function(roomId, verifyLinks=fals
 * @param {string} roomId
 * @param {string} userId
 * @param {module:client.callback} callback Optional.
+ * @param {string} reason Optional.
 * @return {Promise} Resolves: TODO
 * @return {module:http-api.MatrixError} Rejects: with an error response.
 */
-MatrixClient.prototype.invite = function(roomId, userId, callback) {
-    return _membershipChange(this, roomId, userId, "invite", undefined,
+MatrixClient.prototype.invite = function(roomId, userId, callback, reason) {
+    return _membershipChange(this, roomId, userId, "invite", reason,
        callback);
 };

@@ -3841,6 +3853,19 @@ MatrixClient.prototype.setPresence = function(opts, callback) {
    );
 };

+/**
+ * @param {string} userId The user to get presence for
+ * @param {module:client.callback} callback Optional.
+ * @return {Promise} Resolves: The presence state for this user.
+ * @return {module:http-api.MatrixError} Rejects: with an error response.
+ */
+MatrixClient.prototype.getPresence = function(userId, callback) {
+    const path = utils.encodeUri("/presence/$userId/status", {
+        $userId: userId,
+    });
+
+    return this._http.authedRequest(callback, "GET", path, undefined, undefined);
+};

 /**
 * Retrieve older messages from the given room and put them in the timeline.
@@ -4923,6 +4948,57 @@ MatrixClient.prototype.getTurnServers = function() {
    return this._turnServers || [];
 };

+/**
+ * Get the unix timestamp (in seconds) at which the current
+ * TURN credentials (from getTurnServers) expire
+ * @return {number} The expiry timestamp, in seconds, or null if no credentials
+ */
+MatrixClient.prototype.getTurnServersExpiry = function() {
+    return this._turnServersExpiry;
+};
+
+MatrixClient.prototype._checkTurnServers = async function() {
+    if (!this._supportsVoip) {
+        return;
+    }
+
+    let credentialsGood = false;
+    const remainingTime = this._turnServersExpiry - Date.now();
+    if (remainingTime > TURN_CHECK_INTERVAL) {
+        logger.debug("TURN creds are valid for another " + remainingTime + " ms: not fetching new ones.");
+        credentialsGood = true;
+    } else {
+        logger.debug("Fetching new TURN credentials");
+        try {
+            const res = await this.turnServer();
+            if (res.uris) {
+                logger.log("Got TURN URIs: " + res.uris + " refresh in " + res.ttl + " secs");
+                // map the response to a format that can be fed to RTCPeerConnection
+                const servers = {
+                    urls: res.uris,
+                    username: res.username,
+                    credential: res.password,
+                };
+                this._turnServers = [servers];
+                // The TTL is in seconds but we work in ms
+                this._turnServersExpiry = Date.now() + (res.ttl * 1000);
+                credentialsGood = true;
+            }
+        } catch (err) {
+            logger.error("Failed to get TURN URIs", err);
+            // If we get a 403, there's no point in looping forever.
+            if (err.httpStatus === 403) {
+                logger.info("TURN access unavailable for this account: stopping credentials checks");
+                if (this._checkTurnServersIntervalID !== null) global.clearInterval(this._checkTurnServersIntervalID);
+                this._checkTurnServersIntervalID = null;
+            }
+        }
+        // otherwise, if we failed for whatever reason, try again the next time we're called.
+    }
+
+    return credentialsGood;
+};
+
 /**
 * Set whether to allow a fallback ICE server should be used for negotiating a
 * WebRTC connection if the homeserver doesn't provide any servers. Defaults to
@@ -5075,7 +5151,12 @@ MatrixClient.prototype.startClient = async function(opts) {
    }

    // periodically poll for turn servers if we support voip
-    checkTurnServers(this);
+    if (this._supportsVoip) {
+        this._checkTurnServersIntervalID = setInterval(() => {
+            this._checkTurnServers();
+        }, TURN_CHECK_INTERVAL);
+        this._checkTurnServers();
+    }

    if (this._syncApi) {
        // This shouldn't happen since we thought the client was not running
@@ -5187,7 +5268,7 @@ MatrixClient.prototype.stopClient = function() {
        this._callEventHandler = null;
    }

-    global.clearTimeout(this._checkTurnServersTimeoutID);
+    global.clearInterval(this._checkTurnServersIntervalID);
    if (this._clientWellKnownIntervalID !== undefined) {
        global.clearInterval(this._clientWellKnownIntervalID);
    }
@@ -5394,6 +5475,9 @@ async function(roomId, eventId, relationType, eventType, opts = {}) {
        }));
        events = events.filter(e => e.getType() === eventType);
    }
+    if (originalEvent && relationType === "m.replace") {
+        events = events.filter(e => e.getSender() === originalEvent.getSender());
+    }
    return {
        originalEvent,
        events,
@@ -5401,36 +5485,6 @@ async function(roomId, eventId, relationType, eventType, opts = {}) {
    };
 };

-function checkTurnServers(client) {
-    if (!client._supportsVoip) {
-        return;
-    }
-
-    client.turnServer().then(function(res) {
-        if (res.uris) {
-            logger.log("Got TURN URIs: " + res.uris + " refresh in " +
-                res.ttl + " secs");
-            // map the response to a format that can be fed to
-            // RTCPeerConnection
-            const servers = {
-                urls: res.uris,
-                username: res.username,
-                credential: res.password,
-            };
-            client._turnServers = [servers];
-            // re-fetch when we're about to reach the TTL
-            client._checkTurnServersTimeoutID = setTimeout(() => {
-                checkTurnServers(client);
-            }, (res.ttl || (60 * 60)) * 1000 * 0.9);
-        }
-    }, function(err) {
-        logger.error("Failed to get TURN URIs");
-        client._checkTurnServersTimeoutID = setTimeout(function() {
-            checkTurnServers(client);
-        }, 60000);
-    });
-}
-
 function _reject(callback, reject, err) {
    if (callback) {
        callback(err);
@@ -545,6 +545,7 @@ OlmDevice.prototype.createOutboundSession = async function(
                }
            });
        },
+        logger.withPrefix("[createOutboundSession]"),
    );
    return newSessionId;
 };
@@ -605,6 +606,7 @@ OlmDevice.prototype.createInboundSession = async function(
                }
            });
        },
+        logger.withPrefix("[createInboundSession]"),
    );

    return result;
@@ -619,8 +621,10 @@ OlmDevice.prototype.createInboundSession = async function(
 * @return {Promise<string[]>}  a list of known session ids for the device
 */
 OlmDevice.prototype.getSessionIdsForDevice = async function(theirDeviceIdentityKey) {
+    const log = logger.withPrefix("[getSessionIdsForDevice]");
+
    if (this._sessionsInProgress[theirDeviceIdentityKey]) {
-        logger.log("waiting for olm session to be created");
+        log.debug(`Waiting for Olm session for ${theirDeviceIdentityKey} to be created`);
        try {
            await this._sessionsInProgress[theirDeviceIdentityKey];
        } catch (e) {
@@ -638,6 +642,7 @@ OlmDevice.prototype.getSessionIdsForDevice = async function(theirDeviceIdentityK
                },
            );
        },
+        log,
    );

    return sessionIds;
@@ -651,13 +656,14 @@ OlmDevice.prototype.getSessionIdsForDevice = async function(theirDeviceIdentityK
 * @param {boolean} nowait Don't wait for an in-progress session to complete.
 *     This should only be set to true of the calling function is the function
 *     that marked the session as being in-progress.
+ * @param {Logger} [log] A possibly customised log
 * @return {Promise<?string>}  session id, or null if no established session
 */
 OlmDevice.prototype.getSessionIdForDevice = async function(
-    theirDeviceIdentityKey, nowait,
+    theirDeviceIdentityKey, nowait, log,
 ) {
    const sessionInfos = await this.getSessionInfoForDevice(
-        theirDeviceIdentityKey, nowait,
+        theirDeviceIdentityKey, nowait, log,
    );

    if (sessionInfos.length === 0) {
@@ -697,11 +703,16 @@ OlmDevice.prototype.getSessionIdForDevice = async function(
 * @param {boolean} nowait Don't wait for an in-progress session to complete.
 *     This should only be set to true of the calling function is the function
 *     that marked the session as being in-progress.
+ * @param {Logger} [log] A possibly customised log
 * @return {Array.<{sessionId: string, hasReceivedMessage: Boolean}>}
 */
-OlmDevice.prototype.getSessionInfoForDevice = async function(deviceIdentityKey, nowait) {
+OlmDevice.prototype.getSessionInfoForDevice = async function(
+    deviceIdentityKey, nowait, log = logger,
+) {
+    log = log.withPrefix("[getSessionInfoForDevice]");
+
    if (this._sessionsInProgress[deviceIdentityKey] && !nowait) {
-        logger.log("waiting for olm session to be created");
+        log.debug(`Waiting for Olm session for ${deviceIdentityKey} to be created`);
        try {
            await this._sessionsInProgress[deviceIdentityKey];
        } catch (e) {
@@ -727,6 +738,7 @@ OlmDevice.prototype.getSessionInfoForDevice = async function(deviceIdentityKey,
                }
            });
        },
+        log,
    );

    return info;
@@ -761,6 +773,7 @@ OlmDevice.prototype.encryptMessage = async function(
                this._saveSession(theirDeviceIdentityKey, sessionInfo, txn);
            });
        },
+        logger.withPrefix("[encryptMessage]"),
    );
    return res;
 };
@@ -794,6 +807,7 @@ OlmDevice.prototype.decryptMessage = async function(
                this._saveSession(theirDeviceIdentityKey, sessionInfo, txn);
            });
        },
+        logger.withPrefix("[decryptMessage]"),
    );
    return payloadString;
 };
@@ -825,6 +839,7 @@ OlmDevice.prototype.matchesSession = async function(
                matches = sessionInfo.session.matches_inbound(ciphertext);
            });
        },
+        logger.withPrefix("[matchesSession]"),
    );
    return matches;
 };
@@ -1095,6 +1110,7 @@ OlmDevice.prototype.addInboundGroupSession = async function(
                },
            );
        },
+        logger.withPrefix("[addInboundGroupSession]"),
    );
 };

@@ -1265,6 +1281,7 @@ OlmDevice.prototype.decryptGroupMessage = async function(
                },
            );
        },
+        logger.withPrefix("[decryptGroupMessage]"),
    );

    if (error) {
@@ -1310,6 +1327,7 @@ OlmDevice.prototype.hasInboundSessionKeys = async function(roomId, senderKey, se
                },
            );
        },
+        logger.withPrefix("[hasInboundSessionKeys]"),
    );

    return result;
@@ -1369,6 +1387,7 @@ OlmDevice.prototype.getInboundGroupSessionKey = async function(
                },
            );
        },
+        logger.withPrefix("[getInboundGroupSessionKey]"),
    );

    return result;
@@ -264,11 +264,14 @@ MegolmEncryption.prototype._ensureOutboundSession = async function(
        await Promise.all([
            (async () => {
                // share keys with devices that we already have a session for
+                logger.debug(`Sharing keys with existing Olm sessions in ${this._roomId}`);
                await this._shareKeyWithOlmSessions(
                    session, key, payload, olmSessions,
                );
+                logger.debug(`Shared keys with existing Olm sessions in ${this._roomId}`);
            })(),
            (async () => {
+                logger.debug(`Sharing keys (start phase 1) with new Olm sessions in ${this._roomId}`);
                const errorDevices = [];

                // meanwhile, establish olm sessions for devices that we don't
@@ -282,6 +285,7 @@ MegolmEncryption.prototype._ensureOutboundSession = async function(
                    session, key, payload, devicesWithoutSession, errorDevices,
                    singleOlmCreationPhase ? 10000 : 2000, failedServers,
                );
+                logger.debug(`Shared keys (end phase 1) with new Olm sessions in ${this._roomId}`);

                if (!singleOlmCreationPhase && (Date.now() - start < 10000)) {
                    // perform the second phase of olm session creation if requested,
@@ -310,19 +314,24 @@ MegolmEncryption.prototype._ensureOutboundSession = async function(
                            }
                        }

+                        logger.debug(`Sharing keys (start phase 2) with new Olm sessions in ${this._roomId}`);
                        await this._shareKeyWithDevices(
                            session, key, payload, retryDevices, failedDevices, 30000,
                        );
+                        logger.debug(`Shared keys (end phase 2) with new Olm sessions in ${this._roomId}`);

                        await this._notifyFailedOlmDevices(session, key, failedDevices);
                    })();
                } else {
                    await this._notifyFailedOlmDevices(session, key, errorDevices);
                }
+                logger.debug(`Shared keys (all phases done) with new Olm sessions in ${this._roomId}`);
            })(),
            (async () => {
+                logger.debug(`Notifying blocked devices in ${this._roomId}`);
                // also, notify blocked devices that they're blocked
                const blockedMap = {};
+                let blockedCount = 0;
                for (const [userId, userBlockedDevices] of Object.entries(blocked)) {
                    for (const [deviceId, device] of Object.entries(userBlockedDevices)) {
                        if (
@@ -330,12 +339,14 @@ MegolmEncryption.prototype._ensureOutboundSession = async function(
                            session.blockedDevicesNotified[userId][deviceId] === undefined
                        ) {
                            blockedMap[userId] = blockedMap[userId] || {};
-                            blockedMap[userId][deviceId] = {device};
+                            blockedMap[userId][deviceId] = { device };
+                            blockedCount++;
                        }
                    }
                }

                await this._notifyBlockedDevices(session, blockedMap);
+                logger.debug(`Notified ${blockedCount} blocked devices in ${this._roomId}`);
            })(),
        ]);
    };
@@ -348,6 +359,11 @@ MegolmEncryption.prototype._ensureOutboundSession = async function(
    // first wait for the previous share to complete
    const prom = this._setupPromise.then(prepareSession);

+    // Ensure any failures are logged for debugging
+    prom.catch(e => {
+        logger.error(`Failed to ensure outbound session in ${this._roomId}`, e);
+    });
+
    // _setupPromise resolves to `session` whether or not the share succeeds
    this._setupPromise = prom.then(returnSession, returnSession);

@@ -369,17 +385,11 @@ MegolmEncryption.prototype._prepareNewSession = async function() {
        key.key, {ed25519: this._olmDevice.deviceEd25519Key},
    );

-    if (this._crypto.backupInfo) {
-        // don't wait for it to complete
-        this._crypto.backupGroupSession(
-            this._roomId, this._olmDevice.deviceCurve25519Key, [],
-            sessionId, key.key,
-        ).catch((e) => {
-            // This throws if the upload failed, but this is fine
-            // since it will have written it to the db and will retry.
-            logger.log("Failed to back up megolm session", e);
-        });
-    }
+    // don't wait for it to complete
+    this._crypto.backupGroupSession(
+        this._roomId, this._olmDevice.deviceCurve25519Key, [],
+        sessionId, key.key,
+    );

    return new OutboundSessionInfo(sessionId);
 };
@@ -723,13 +733,18 @@ MegolmEncryption.prototype.reshareKeyWithDevice = async function(
 MegolmEncryption.prototype._shareKeyWithDevices = async function(
    session, key, payload, devicesByUser, errorDevices, otkTimeout, failedServers,
 ) {
+    logger.debug(`Ensuring Olm sessions for devices in ${this._roomId}`);
    const devicemap = await olmlib.ensureOlmSessionsForDevices(
        this._olmDevice, this._baseApis, devicesByUser, otkTimeout, failedServers,
+        logger.withPrefix(`[${this._roomId}]`),
    );
+    logger.debug(`Ensured Olm sessions for devices in ${this._roomId}`);

    this._getDevicesWithoutSessions(devicemap, devicesByUser, errorDevices);

+    logger.debug(`Sharing keys with Olm sessions in ${this._roomId}`);
    await this._shareKeyWithOlmSessions(session, key, payload, devicemap);
+    logger.debug(`Shared keys with Olm sessions in ${this._roomId}`);
 };

 MegolmEncryption.prototype._shareKeyWithOlmSessions = async function(
@@ -738,16 +753,17 @@ MegolmEncryption.prototype._shareKeyWithOlmSessions = async function(
    const userDeviceMaps = this._splitDevices(devicemap);

    for (let i = 0; i < userDeviceMaps.length; i++) {
+        const taskDetail =
+            `megolm keys for ${session.sessionId} ` +
+            `in ${this._roomId} (slice ${i + 1}/${userDeviceMaps.length})`;
        try {
+            logger.debug(`Sharing ${taskDetail}`);
            await this._encryptAndSendKeysToDevices(
                session, key.chain_index, userDeviceMaps[i], payload,
            );
-            logger.log(`Completed megolm keyshare for ${session.sessionId} `
-                + `in ${this._roomId} (slice ${i + 1}/${userDeviceMaps.length})`);
+            logger.debug(`Shared ${taskDetail}`);
        } catch (e) {
-            logger.log(`megolm keyshare for ${session.sessionId} in ${this._roomId} `
-                + `(slice ${i + 1}/${userDeviceMaps.length}) failed`);
-
+            logger.error(`Failed to share ${taskDetail}`);
            throw e;
        }
    }
@@ -766,6 +782,11 @@ MegolmEncryption.prototype._shareKeyWithOlmSessions = async function(
 MegolmEncryption.prototype._notifyFailedOlmDevices = async function(
    session, key, failedDevices,
 ) {
+    logger.debug(
+        `Notifying ${failedDevices.length} devices we failed to ` +
+        `create Olm sessions in ${this._roomId}`,
+    );
+
    // mark the devices that failed as "handled" because we don't want to try
    // to claim a one-time-key for dead devices on every message.
    for (const {userId, deviceInfo} of failedDevices) {
@@ -780,6 +801,10 @@ MegolmEncryption.prototype._notifyFailedOlmDevices = async function(
          await this._olmDevice.filterOutNotifiedErrorDevices(
              failedDevices,
          );
+    logger.debug(
+        `Filtered down to ${filteredFailedDevices.length} error devices ` +
+        `in ${this._roomId}`,
+    );
    const blockedMap = {};
    for (const {userId, deviceInfo} of filteredFailedDevices) {
        blockedMap[userId] = blockedMap[userId] || {};
@@ -797,6 +822,10 @@ MegolmEncryption.prototype._notifyFailedOlmDevices = async function(

    // send the notifications
    await this._notifyBlockedDevices(session, blockedMap);
+    logger.debug(
+        `Notified ${filteredFailedDevices.length} devices we failed to ` +
+        `create Olm sessions in ${this._roomId}`,
+    );
 };

 /**
@@ -846,24 +875,41 @@ MegolmEncryption.prototype.prepareToEncrypt = function(room) {
        // We're already preparing something, so don't do anything else.
        // FIXME: check if we need to restart
        // (https://github.com/matrix-org/matrix-js-sdk/issues/1255)
+        const elapsedTime = Date.now() - this.encryptionPreparationMetadata.startTime;
+        logger.debug(
+            `Already started preparing to encrypt for ${this._roomId} ` +
+            `${elapsedTime} ms ago, skipping`,
+        );
        return;
    }

    logger.debug(`Preparing to encrypt events for ${this._roomId}`);

+    this.encryptionPreparationMetadata = {
+        startTime: Date.now(),
+    };
    this.encryptionPreparation = (async () => {
-        const [devicesInRoom, blocked] = await this._getDevicesInRoom(room);
+        try {
+            logger.debug(`Getting devices in ${this._roomId}`);
+            const [devicesInRoom, blocked] = await this._getDevicesInRoom(room);

-        if (this._crypto.getGlobalErrorOnUnknownDevices()) {
-            // Drop unknown devices for now.  When the message gets sent, we'll
-            // throw an error, but we'll still be prepared to send to the known
-            // devices.
-            this._removeUnknownDevices(devicesInRoom);
+            if (this._crypto.getGlobalErrorOnUnknownDevices()) {
+                // Drop unknown devices for now.  When the message gets sent, we'll
+                // throw an error, but we'll still be prepared to send to the known
+                // devices.
+                this._removeUnknownDevices(devicesInRoom);
+            }
+
+            logger.debug(`Ensuring outbound session in ${this._roomId}`);
+            await this._ensureOutboundSession(devicesInRoom, blocked, true);
+
+            logger.debug(`Ready to encrypt events for ${this._roomId}`);
+        } catch (e) {
+            logger.error(`Failed to prepare to encrypt events for ${this._roomId}`, e);
+        } finally {
+            delete this.encryptionPreparationMetadata;
+            delete this.encryptionPreparation;
        }
-
-        await this._ensureOutboundSession(devicesInRoom, blocked, true);
-
-        delete this.encryptionPreparation;
    })();
 };

@@ -1347,18 +1393,12 @@ MegolmDecryption.prototype.onRoomKeyEvent = function(event) {
                }
            });
    }).then(() => {
-        if (this._crypto.backupInfo) {
-            // don't wait for the keys to be backed up for the server
-            this._crypto.backupGroupSession(
-                content.room_id, senderKey, forwardingKeyChain,
-                content.session_id, content.session_key, keysClaimed,
-                exportFormat,
-            ).catch((e) => {
-                // This throws if the upload failed, but this is fine
-                // since it will have written it to the db and will retry.
-                logger.log("Failed to back up megolm session", e);
-            });
-        }
+        // don't wait for the keys to be backed up for the server
+        this._crypto.backupGroupSession(
+            content.room_id, senderKey, forwardingKeyChain,
+            content.session_id, content.session_key, keysClaimed,
+            exportFormat,
+        );
    }).catch((e) => {
        logger.error(`Error handling m.room_key_event: ${e}`);
    });
@@ -1564,7 +1604,7 @@ MegolmDecryption.prototype.importRoomKey = function(session, opts = {}) {
        true,
        opts.untrusted ? { untrusted: opts.untrusted } : {},
    ).then(() => {
-        if (this._crypto.backupInfo && opts.source !== "backup") {
+        if (opts.source !== "backup") {
            // don't wait for it to complete
            this._crypto.backupGroupSession(
                session.room_id,
@@ -57,6 +57,7 @@ import {IllegalMethod} from "./verification/IllegalMethod";
 import {KeySignatureUploadError} from "../errors";
 import {decryptAES, encryptAES} from './aes';
 import {DehydrationManager} from './dehydration';
+import { MatrixEvent } from "../models/event";

 const DeviceVerification = DeviceInfo.DeviceVerification;

@@ -2884,18 +2885,18 @@ Crypto.prototype.backupGroupSession = async function(
    sessionId, sessionKey, keysClaimed,
    exportFormat,
 ) {
-    if (!this.backupInfo) {
-        throw new Error("Key backups are not enabled");
-    }
-
    await this._cryptoStore.markSessionsNeedingBackup([{
        senderKey: senderKey,
        sessionId: sessionId,
    }]);

-    // don't wait for this to complete: it will delay so
-    // happens in the background
-    this.scheduleKeyBackupSend();
+    if (this.backupInfo) {
+        // don't wait for this to complete: it will delay so
+        // happens in the background
+        this.scheduleKeyBackupSend();
+    }
+    // if this.backupInfo is not set, then the keys will be backed up when
+    // client.enableKeyBackup is called
 };

 /**
@@ -3028,19 +3029,26 @@ Crypto.prototype.encryptEvent = async function(event, room) {
 *  finished decrypting. Rejects with an `algorithms.DecryptionError` if there
 *  is a problem decrypting the event.
 */
-Crypto.prototype.decryptEvent = function(event) {
+Crypto.prototype.decryptEvent = async function(event) {
    if (event.isRedacted()) {
-        return Promise.resolve({
+        const redactionEvent = new MatrixEvent(event.getUnsigned().redacted_because);
+        const decryptedEvent = await this.decryptEvent(redactionEvent);
+
+        return {
            clearEvent: {
                room_id: event.getRoomId(),
                type: "m.room.message",
                content: {},
+                unsigned: {
+                    redacted_because: decryptedEvent.clearEvent,
+                },
            },
-        });
+        };
+    } else {
+        const content = event.getWireContent();
+        const alg = this._getRoomDecryptor(event.getRoomId(), content.algorithm);
+        return await alg.decryptEvent(event);
    }
-    const content = event.getWireContent();
-    const alg = this._getRoomDecryptor(event.getRoomId(), content.algorithm);
-    return alg.decryptEvent(event);
 };

 /**
@@ -183,18 +183,24 @@ export async function getExistingOlmSessions(
 * @param {Array} [failedServers] An array to fill with remote servers that
 *     failed to respond to one-time-key requests.
 *
+ * @param {Logger} [log] A possibly customised log
+ *
 * @return {Promise} resolves once the sessions are complete, to
 *    an Object mapping from userId to deviceId to
 *    {@link module:crypto~OlmSessionResult}
 */
 export async function ensureOlmSessionsForDevices(
-    olmDevice, baseApis, devicesByUser, force, otkTimeout, failedServers,
+    olmDevice, baseApis, devicesByUser, force, otkTimeout, failedServers, log,
 ) {
    if (typeof force === "number") {
+        log = failedServers;
        failedServers = otkTimeout;
        otkTimeout = force;
        force = false;
    }
+    if (!log) {
+        log = logger;
+    }

    const devicesWithoutSession = [
        // [userId, deviceId], ...
@@ -202,6 +208,35 @@ export async function ensureOlmSessionsForDevices(
    const result = {};
    const resolveSession = {};

+    // Mark all sessions this task intends to update as in progress. It is
+    // important to do this for all devices this task cares about in a single
+    // synchronous operation, as otherwise it is possible to have deadlocks
+    // where multiple tasks wait indefinitely on another task to update some set
+    // of common devices.
+    for (const [, devices] of Object.entries(devicesByUser)) {
+        for (const deviceInfo of devices) {
+            const key = deviceInfo.getIdentityKey();
+
+            if (key === olmDevice.deviceCurve25519Key) {
+                // We don't start sessions with ourself, so there's no need to
+                // mark it in progress.
+                continue;
+            }
+
+            if (!olmDevice._sessionsInProgress[key]) {
+                // pre-emptively mark the session as in-progress to avoid race
+                // conditions.  If we find that we already have a session, then
+                // we'll resolve
+                olmDevice._sessionsInProgress[key] = new Promise(resolve => {
+                    resolveSession[key] = (...args) => {
+                        delete olmDevice._sessionsInProgress[key];
+                        resolve(...args);
+                    };
+                });
+            }
+        }
+    }
+
    for (const [userId, devices] of Object.entries(devicesByUser)) {
        result[userId] = {};
        for (const deviceInfo of devices) {
@@ -216,7 +251,7 @@ export async function ensureOlmSessionsForDevices(
                // new chain when this side has an active sender chain.
                // If you see this message being logged in the wild, we should find
                // the thing that is trying to send Olm messages to itself and fix it.
-                logger.info("Attempted to start session with ourself! Ignoring");
+                log.info("Attempted to start session with ourself! Ignoring");
                // We must fill in the section in the return value though, as callers
                // expect it to be there.
                result[userId][deviceId] = {
@@ -226,41 +261,21 @@ export async function ensureOlmSessionsForDevices(
                continue;
            }

-            if (!olmDevice._sessionsInProgress[key]) {
-                // pre-emptively mark the session as in-progress to avoid race
-                // conditions.  If we find that we already have a session, then
-                // we'll resolve
-                olmDevice._sessionsInProgress[key] = new Promise(
-                    (resolve, reject) => {
-                        resolveSession[key] = {
-                            resolve: (...args) => {
-                                delete olmDevice._sessionsInProgress[key];
-                                resolve(...args);
-                            },
-                            reject: (...args) => {
-                                delete olmDevice._sessionsInProgress[key];
-                                reject(...args);
-                            },
-                        };
-                    },
-                );
-            }
+            const forWhom = `for ${key} (${userId}:${deviceId})`;
            const sessionId = await olmDevice.getSessionIdForDevice(
-                key, resolveSession[key],
+                key, resolveSession[key], log,
            );
            if (sessionId !== null && resolveSession[key]) {
                // we found a session, but we had marked the session as
-                // in-progress, so unmark it and unblock anything that was
-                // waiting
-                delete olmDevice._sessionsInProgress[key];
-                resolveSession[key].resolve();
-                delete resolveSession[key];
+                // in-progress, so resolve it now, which will unmark it and
+                // unblock anything that was waiting
+                resolveSession[key]();
            }
            if (sessionId === null || force) {
                if (force) {
-                    logger.info("Forcing new Olm session for " + userId + ":" + deviceId);
+                    log.info(`Forcing new Olm session ${forWhom}`);
                } else {
-                    logger.info("Making new Olm session for " + userId + ":" + deviceId);
+                    log.info(`Making new Olm session ${forWhom}`);
                }
                devicesWithoutSession.push([userId, deviceId]);
            }
@@ -277,15 +292,18 @@ export async function ensureOlmSessionsForDevices(

    const oneTimeKeyAlgorithm = "signed_curve25519";
    let res;
+    let taskDetail = `one-time keys for ${devicesWithoutSession.length} devices`;
    try {
+        log.debug(`Claiming ${taskDetail}`);
        res = await baseApis.claimOneTimeKeys(
            devicesWithoutSession, oneTimeKeyAlgorithm, otkTimeout,
        );
+        log.debug(`Claimed ${taskDetail}`);
    } catch (e) {
        for (const resolver of Object.values(resolveSession)) {
-            resolver.resolve();
+            resolver();
        }
-        logger.log("failed to claim one-time keys", e, devicesWithoutSession);
+        log.log(`Failed to claim ${taskDetail}`, e, devicesWithoutSession);
        throw e;
    }

@@ -293,10 +311,10 @@ export async function ensureOlmSessionsForDevices(
        failedServers.push(...Object.keys(res.failures));
    }

-    const otk_res = res.one_time_keys || {};
+    const otkResult = res.one_time_keys || {};
    const promises = [];
    for (const [userId, devices] of Object.entries(devicesByUser)) {
-        const userRes = otk_res[userId] || {};
+        const userRes = otkResult[userId] || {};
        for (let j = 0; j < devices.length; j++) {
            const deviceInfo = devices[j];
            const deviceId = deviceInfo.deviceId;
@@ -323,11 +341,12 @@ export async function ensureOlmSessionsForDevices(
            }

            if (!oneTimeKey) {
-                const msg = "No one-time keys (alg=" + oneTimeKeyAlgorithm +
-                      ") for device " + userId + ":" + deviceId;
-                logger.warn(msg);
+                log.warn(
+                    `No one-time keys (alg=${oneTimeKeyAlgorithm}) ` +
+                    `for device ${userId}:${deviceId}`,
+                );
                if (resolveSession[key]) {
-                    resolveSession[key].resolve();
+                    resolveSession[key]();
                }
                continue;
            }
@@ -337,12 +356,12 @@ export async function ensureOlmSessionsForDevices(
                    olmDevice, oneTimeKey, userId, deviceInfo,
                ).then((sid) => {
                    if (resolveSession[key]) {
-                        resolveSession[key].resolve(sid);
+                        resolveSession[key](sid);
                    }
                    result[userId][deviceId].sessionId = sid;
                }, (e) => {
                    if (resolveSession[key]) {
-                        resolveSession[key].resolve();
+                        resolveSession[key]();
                    }
                    throw e;
                }),
@@ -350,7 +369,10 @@ export async function ensureOlmSessionsForDevices(
        }
    }

+    taskDetail = `Olm sessions for ${promises.length} devices`;
+    log.debug(`Starting ${taskDetail}`);
    await Promise.all(promises);
+    log.debug(`Started ${taskDetail}`);
    return result;
 }

@@ -20,6 +20,7 @@ import {logger} from '../../logger';
 import * as utils from "../../utils";

 export const VERSION = 9;
+const PROFILE_TRANSACTIONS = false;

 /**
 * Implementation of a CryptoStore which is backed by an existing
@@ -34,6 +35,7 @@ export class Backend {
     */
    constructor(db) {
        this._db = db;
+        this._nextTxnId = 0;

        // make sure we close the db on `onversionchange` - otherwise
        // attempts to delete the database will block (and subsequent
@@ -757,10 +759,27 @@ export class Backend {
        }));
    }

-    doTxn(mode, stores, func) {
+    doTxn(mode, stores, func, log = logger) {
+        let startTime;
+        let description;
+        if (PROFILE_TRANSACTIONS) {
+            const txnId = this._nextTxnId++;
+            startTime = Date.now();
+            description = `${mode} crypto store transaction ${txnId} in ${stores}`;
+            log.debug(`Starting ${description}`);
+        }
        const txn = this._db.transaction(stores, mode);
        const promise = promiseifyTxn(txn);
        const result = func(txn);
+        if (PROFILE_TRANSACTIONS) {
+            promise.then(() => {
+                const elapsedTime = Date.now() - startTime;
+                log.debug(`Finished ${description}, took ${elapsedTime} ms`);
+            }, () => {
+                const elapsedTime = Date.now() - startTime;
+                log.error(`Failed ${description}, took ${elapsedTime} ms`);
+            });
+        }
        return promise.then(() => {
            return result;
        });
@@ -596,6 +596,7 @@ export class IndexedDBCryptoStore {
     * @param {function(*)} func Function called with the
     *     transaction object: an opaque object that should be passed
     *     to store functions.
+     * @param {Logger} [log] A possibly customised log
     * @return {Promise} Promise that resolves with the result of the `func`
     *     when the transaction is complete. If the backend is
     *     async (ie. the indexeddb backend) any of the callback
@@ -603,8 +604,8 @@ export class IndexedDBCryptoStore {
     *     reject with that exception. On synchronous backends, the
     *     exception will propagate to the caller of the getFoo method.
     */
-    doTxn(mode, stores, func) {
-        return this._backend.doTxn(mode, stores, func);
+    doTxn(mode, stores, func, log) {
+        return this._backend.doTxn(mode, stores, func, log);
    }
 }

@@ -1,6 +1,6 @@
 /*
 Copyright 2018 André Jaenisch
-Copyright 2019 The Matrix.org Foundation C.I.C.
+Copyright 2019, 2021 The Matrix.org Foundation C.I.C.

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -19,7 +19,7 @@ limitations under the License.
 * @module logger
 */

-import log from "loglevel";
+import log, { Logger } from "loglevel";

 // This is to demonstrate, that you can use any namespace you want.
 // Namespaces allow you to turn on/off the logging for specific parts of the
@@ -36,6 +36,11 @@ const DEFAULT_NAMESPACE = "matrix";
 // when logging so we always get the current value of console methods.
 log.methodFactory = function(methodName, logLevel, loggerName) {
    return function(...args) {
+        /* eslint-disable babel/no-invalid-this */
+        if (this.prefix) {
+            args.unshift(this.prefix);
+        }
+        /* eslint-enable babel/no-invalid-this */
        const supportedByConsole = methodName === "error" ||
            methodName === "warn" ||
            methodName === "trace" ||
@@ -54,6 +59,30 @@ log.methodFactory = function(methodName, logLevel, loggerName) {
 * Drop-in replacement for <code>console</code> using {@link https://www.npmjs.com/package/loglevel|loglevel}.
 * Can be tailored down to specific use cases if needed.
 */
-export const logger = log.getLogger(DEFAULT_NAMESPACE);
+export const logger: PrefixedLogger = log.getLogger(DEFAULT_NAMESPACE);
 logger.setLevel(log.levels.DEBUG);

+interface PrefixedLogger extends Logger {
+    withPrefix?: (prefix: string) => PrefixedLogger;
+    prefix?: string;
+}
+
+function extendLogger(logger: PrefixedLogger) {
+    logger.withPrefix = function(prefix: string): PrefixedLogger {
+        const existingPrefix = this.prefix || "";
+        return getPrefixedLogger(existingPrefix + prefix);
+    };
+}
+
+extendLogger(logger);
+
+function getPrefixedLogger(prefix): PrefixedLogger {
+    const prefixLogger: PrefixedLogger = log.getLogger(`${DEFAULT_NAMESPACE}-${prefix}`);
+    if (prefixLogger.prefix !== prefix) {
+        // Only do this setup work the first time through, as loggers are saved by name.
+        extendLogger(prefixLogger);
+        prefixLogger.prefix = prefix;
+        prefixLogger.setLevel(log.levels.DEBUG);
+    }
+    return prefixLogger;
+}
@@ -52,7 +52,7 @@ export * from "./store/session/webstorage";
 export * from "./crypto/store/memory-crypto-store";
 export * from "./crypto/store/indexeddb-crypto-store";
 export * from "./content-repo";
-export const ContentHelpers = import("./content-helpers");
+export * as ContentHelpers from "./content-helpers";
 export {
    createNewMatrixCall,
    setAudioOutput as setMatrixCallAudioOutput,
@@ -142,6 +142,7 @@ export interface ICreateClientOpts {
    unstableClientRelationAggregation?: boolean;
    verificationMethods?: Array<any>;
    forceTURN?: boolean;
+    iceCandidatePoolSize?: number,
    supportsCallTransfer?: boolean,
    fallbackICEServerAllowed?: boolean;
    cryptoCallbacks?: ICryptoCallbacks;
@@ -811,6 +811,24 @@ utils.extend(MatrixEvent.prototype, {
        return this.getType() === "m.room.redaction";
    },

+    /**
+     * Get the (decrypted, if necessary) redaction event JSON
+     * if event was redacted
+     *
+     * @returns {object} The redaction event JSON, or an empty object
+     */
+    getRedactionEvent: function() {
+        if (!this.isRedacted()) return null;
+
+        if (this._clearEvent.unsigned) {
+            return this._clearEvent.unsigned.redacted_because;
+        } else if (this.event.unsigned.redacted_because) {
+            return this.event.unsigned.redacted_because;
+        } else {
+            return {};
+        }
+    },
+
    /**
     * Get the push actions, if known, for this event
     *
@@ -290,6 +290,9 @@ RoomMember.prototype.getMxcAvatarUrl = function() {
    return null;
 };

+const MXID_PATTERN = /@.+:.+/;
+const LTR_RTL_PATTERN = /[\u200E\u200F\u202A-\u202F]/;
+
 function calculateDisplayName(selfUserId, displayName, roomState) {
    if (!displayName || displayName === selfUserId) {
        return selfUserId;
@@ -308,13 +311,13 @@ function calculateDisplayName(selfUserId, displayName, roomState) {
    // Next check if the name contains something that look like a mxid
    // If it does, it may be someone trying to impersonate someone else
    // Show full mxid in this case
-    let disambiguate = /@.+:.+/.test(displayName);
+    let disambiguate = MXID_PATTERN.test(displayName);

    if (!disambiguate) {
        // Also show mxid if the display name contains any LTR/RTL characters as these
        // make it very difficult for us to find similar *looking* display names
        // E.g "Mark" could be cloned by writing "kraM" but in RTL.
-        disambiguate = /[\u200E\u200F\u202A-\u202F]/.test(displayName);
+        disambiguate = LTR_RTL_PATTERN.test(displayName);
    }

    if (!disambiguate) {
@@ -23,6 +23,7 @@ import {EventEmitter} from "events";
 import {RoomMember} from "./room-member";
 import {logger} from '../logger';
 import * as utils from "../utils";
+import {EventType} from "../@types/event";

 // possible statuses for out-of-band member loading
 const OOB_STATUS_NOTSTARTED = 1;
@@ -718,6 +719,16 @@ RoomState.prototype.mayTriggerNotifOfType = function(notifLevelKey, userId) {
    return member.powerLevel >= notifLevel;
 };

+/**
+ * Returns the join rule based on the m.room.join_rule state event, defaulting to `invite`.
+ * @returns {string} the join_rule applied to this room
+ */
+RoomState.prototype.getJoinRule = function() {
+    const joinRuleEvent = this.getStateEvents(EventType.RoomJoinRules, "");
+    const joinRuleContent = joinRuleEvent ? joinRuleEvent.getContent() : {};
+    return joinRuleContent["join_rule"] || "invite";
+};
+

 function _updateThirdPartyTokenCache(roomState, memberEvent) {
    if (!memberEvent.getContent().third_party_invite) {
@@ -30,6 +30,7 @@ import {RoomMember} from "./room-member";
 import {RoomSummary} from "./room-summary";
 import {logger} from '../logger';
 import {ReEmitter} from '../ReEmitter';
+import {EventType, RoomCreateTypeField, RoomType} from "../@types/event";

 // These constants are used as sane defaults when the homeserver doesn't support
 // the m.room_versions capability. In practice, KNOWN_SAFE_ROOM_VERSION should be
@@ -817,7 +818,7 @@ Room.prototype.getBlacklistUnverifiedDevices = function() {
 */
 Room.prototype.getAvatarUrl = function(baseUrl, width, height, resizeMethod,
                                       allowDefault) {
-    const roomAvatarEvent = this.currentState.getStateEvents("m.room.avatar", "");
+    const roomAvatarEvent = this.currentState.getStateEvents(EventType.RoomAvatar, "");
    if (allowDefault === undefined) {
        allowDefault = true;
    }
@@ -835,6 +836,15 @@ Room.prototype.getAvatarUrl = function(baseUrl, width, height, resizeMethod,
    return null;
 };

+/**
+ * Get the mxc avatar url for the room, if one was set.
+ * @return {string} the mxc avatar url or falsy
+ */
+Room.prototype.getMxcAvatarUrl = function() {
+    const roomAvatarEvent = this.currentState.getStateEvents(EventType.RoomAvatar, "");
+    return roomAvatarEvent ? roomAvatarEvent.getContent().url : null;
+};
+
 /**
 * Get the aliases this room has according to the room's state
 * The aliases returned by this function may not necessarily
@@ -1822,7 +1832,7 @@ Room.prototype.getAccountData = function(type) {


 /**
- * Returns wheter the syncing user has permission to send a message in the room
+ * Returns whether the syncing user has permission to send a message in the room
 * @return {boolean} true if the user should be permitted to send
 *                   message events into the room.
 */
@@ -1831,6 +1841,51 @@ Room.prototype.maySendMessage = function() {
        this.currentState.maySendEvent('m.room.message', this.myUserId);
 };

+/**
+ * Returns whether the given user has permissions to issue an invite for this room.
+ * @param {string} userId the ID of the Matrix user to check permissions for
+ * @returns {boolean} true if the user should be permitted to issue invites for this room.
+ */
+Room.prototype.canInvite = function(userId) {
+    let canInvite = this.getMyMembership() === "join";
+    const powerLevelsEvent = this.currentState.getStateEvents(EventType.RoomPowerLevels, "");
+    const powerLevels = powerLevelsEvent && powerLevelsEvent.getContent();
+    const me = this.getMember(userId);
+    if (powerLevels && me && powerLevels.invite > me.powerLevel) {
+        canInvite = false;
+    }
+    return canInvite;
+};
+
+/**
+ * Returns the join rule based on the m.room.join_rule state event, defaulting to `invite`.
+ * @returns {string} the join_rule applied to this room
+ */
+Room.prototype.getJoinRule = function() {
+    return this.currentState.getJoinRule();
+};
+
+/**
+ * Returns the type of the room from the `m.room.create` event content or undefined if none is set
+ * @returns {?string} the type of the room. Currently only RoomType.Space is known.
+ */
+Room.prototype.getType = function() {
+    const createEvent = this.currentState.getStateEvents("m.room.create", "");
+    if (!createEvent) {
+        logger.warn("Room " + this.roomId + " does not have an m.room.create event");
+        return undefined;
+    }
+    return createEvent.getContent()[RoomCreateTypeField];
+};
+
+/**
+ * Returns whether the room is a space-room as defined by MSC1772.
+ * @returns {boolean} true if the room's type is RoomType.Space
+ */
+Room.prototype.isSpaceRoom = function() {
+    return this.getType() === RoomType.Space;
+};
+
 /**
 * This is an internal method. Calculates the name of the room from the current
 * room state.
@@ -2048,3 +2103,12 @@ function memberNamesToRoomName(names, count = (names.length + 1)) {
 *
 * @param {EventStatus} oldStatus The previous event status.
 */
+
+/**
+ * Fires when the logged in user's membership in the room is updated.
+ *
+ * @event module:models/room~Room#"Room.myMembership"
+ * @param {Room} room The room in which the membership has been updated
+ * @param {string} membership The new membership value
+ * @param {string} prevMembership The previous membership value
+ */
@@ -15,9 +15,24 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

+const LOWERCASE = "abcdefghijklmnopqrstuvwxyz";
+const UPPERCASE = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+const DIGITS = "0123456789";
+
 export function randomString(len: number): string {
+    return randomStringFrom(len, UPPERCASE + LOWERCASE + DIGITS);
+}
+
+export function randomLowercaseString(len: number): string {
+    return randomStringFrom(len, LOWERCASE);
+}
+
+export function randomUppercaseString(len: number): string {
+    return randomStringFrom(len, UPPERCASE);
+}
+
+function randomStringFrom(len: number, chars: string): string {
    let ret = "";
-    const chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

    for (let i = 0; i < len; ++i) {
        ret += chars.charAt(Math.floor(Math.random() * chars.length));
@@ -164,7 +164,7 @@ MatrixScheduler.RETRY_BACKOFF_RATELIMIT = function(event, attempts, err) {

    if (err.name === "M_LIMIT_EXCEEDED") {
        const waitTime = err.data.retry_after_ms;
-        if (waitTime) {
+        if (waitTime > 0) {
            return waitTime;
        }
    }
@@ -435,7 +435,7 @@ LocalIndexedDBStoreBackend.prototype = {
     * @return {Promise} Resolves if the data was persisted.
     */
    _persistSyncData: function(nextBatch, roomsData, groupsData) {
-        logger.log("Persisting sync data up to ", nextBatch);
+        logger.log("Persisting sync data up to", nextBatch);
        return utils.promiseTry(() => {
            const txn = this.db.transaction(["sync"], "readwrite");
            const store = txn.objectStore("sync");
@@ -51,8 +51,8 @@ const WRITE_DELAY_MS = 1000 * 60 * 5; // once every 5 minutes
 * sync from the server is not required. This does not reduce memory usage as all
 * the data is eagerly fetched when <code>startup()</code> is called.
 * <pre>
- * let opts = { localStorage: window.localStorage };
- * let store = new IndexedDBStore();
+ * let opts = { indexedDB: window.indexedDB, localStorage: window.localStorage };
+ * let store = new IndexedDBStore(opts);
 * await store.startup(); // load from indexed db
 * let client = sdk.createClient({
 *     store: store,
@@ -93,7 +93,7 @@ export function SyncApi(client, opts) {
        };
    }
    this.opts = opts;
-    this._peekRoomId = null;
+    this._peekRoom = null;
    this._currentSyncRequest = null;
    this._syncState = null;
    this._syncStateData = null; // additional data (eg. error object for failed sync)
@@ -264,17 +264,18 @@ SyncApi.prototype.syncLeftRooms = function() {
 * store.
 */
 SyncApi.prototype.peek = function(roomId) {
-    const self = this;
+    if (this._peekRoom && this._peekRoom.roomId === roomId) {
+        return Promise.resolve(this._peekRoom);
+    }
+
    const client = this.client;
-    this._peekRoomId = roomId;
-    return this.client.roomInitialSync(roomId, 20).then(function(response) {
+    this._peekRoom = this.createRoom(roomId);
+    return this.client.roomInitialSync(roomId, 20).then((response) => {
        // make sure things are init'd
        response.messages = response.messages || {};
        response.messages.chunk = response.messages.chunk || [];
        response.state = response.state || [];

-        const peekRoom = self.createRoom(roomId);
-
        // FIXME: Mostly duplicated from _processRoomEvents but not entirely
        // because "state" in this API is at the BEGINNING of the chunk
        const oldStateEvents = utils.map(
@@ -309,28 +310,28 @@ SyncApi.prototype.peek = function(roomId) {
        // fire off pagination requests in response to the Room.timeline
        // events.
        if (response.messages.start) {
-            peekRoom.oldState.paginationToken = response.messages.start;
+            this._peekRoom.oldState.paginationToken = response.messages.start;
        }

        // set the state of the room to as it was after the timeline executes
-        peekRoom.oldState.setStateEvents(oldStateEvents);
-        peekRoom.currentState.setStateEvents(stateEvents);
+        this._peekRoom.oldState.setStateEvents(oldStateEvents);
+        this._peekRoom.currentState.setStateEvents(stateEvents);

-        self._resolveInvites(peekRoom);
-        peekRoom.recalculate();
+        this._resolveInvites(this._peekRoom);
+        this._peekRoom.recalculate();

        // roll backwards to diverge old state. addEventsToTimeline
        // will overwrite the pagination token, so make sure it overwrites
        // it with the right thing.
-        peekRoom.addEventsToTimeline(messages.reverse(), true,
-                                     peekRoom.getLiveTimeline(),
+        this._peekRoom.addEventsToTimeline(messages.reverse(), true,
+                                     this._peekRoom.getLiveTimeline(),
                                     response.messages.start);

-        client.store.storeRoom(peekRoom);
-        client.emit("Room", peekRoom);
+        client.store.storeRoom(this._peekRoom);
+        client.emit("Room", this._peekRoom);

-        self._peekPoll(peekRoom);
-        return peekRoom;
+        this._peekPoll(this._peekRoom);
+        return this._peekRoom;
    });
 };

@@ -339,16 +340,16 @@ SyncApi.prototype.peek = function(roomId) {
 * peeked.
 */
 SyncApi.prototype.stopPeeking = function() {
-    this._peekRoomId = null;
+    this._peekRoom = null;
 };

 /**
 * Do a peek room poll.
 * @param {Room} peekRoom
- * @param {string} token from= token
+ * @param {string?} token from= token
 */
 SyncApi.prototype._peekPoll = function(peekRoom, token) {
-    if (this._peekRoomId !== peekRoom.roomId) {
+    if (this._peekRoom !== peekRoom) {
        debuglog("Stopped peeking in room %s", peekRoom.roomId);
        return;
    }
@@ -360,7 +361,7 @@ SyncApi.prototype._peekPoll = function(peekRoom, token) {
        timeout: 30 * 1000,
        from: token,
    }, undefined, 50 * 1000).then(function(res) {
-        if (self._peekRoomId !== peekRoom.roomId) {
+        if (self._peekRoom !== peekRoom) {
            debuglog("Stopped peeking in room %s", peekRoom.roomId);
            return;
        }
@@ -174,6 +174,11 @@ export enum CallErrorCode {
    SignallingFailed = 'signalling_timeout',
 }

+enum ConstraintsType {
+    Audio = "audio",
+    Video = "video",
+}
+
 /**
 * The version field that we set in m.call.* events
 */
@@ -185,6 +190,21 @@ const FALLBACK_ICE_SERVER = 'stun:turn.matrix.org';
 /** The length of time a call can be ringing for. */
 const CALL_TIMEOUT_MS = 60000;

+/** Retrieves sources from desktopCapturer */
+export function getDesktopCapturerSources(): Promise<Array<DesktopCapturerSource>> {
+    const options: GetSourcesOptions = {
+        thumbnailSize: {
+            height: 176,
+            width: 312,
+        },
+        types: [
+            "screen",
+            "window",
+        ],
+    };
+    return window.electron.getDesktopCapturerSources(options);
+}
+
 export class CallError extends Error {
    code : string;

@@ -196,8 +216,8 @@ export class CallError extends Error {
    }
 }

-function genCallID() {
-    return Date.now() + randomString(16);
+function genCallID(): string {
+    return Date.now().toString() + randomString(16);
 }

 /**
@@ -236,8 +256,6 @@ export class MatrixCall extends EventEmitter {
    private localAVStream: MediaStream;
    private inviteOrAnswerSent: boolean;
    private waitForLocalAVStream: boolean;
-    // XXX: This is either the invite or answer from remote...
-    private msg: any;
    // XXX: I don't know why this is called 'config'.
    private config: MediaStreamConstraints;
    private successor: MatrixCall;
@@ -260,10 +278,20 @@ export class MatrixCall extends EventEmitter {
    private micMuted;
    private vidMuted;

+    // the stats for the call at the point it ended. We can't get these after we
+    // tear the call down, so we just grab a snapshot before we stop the call.
+    // The typescript definitions have this type as 'any' :(
+    private callStatsAtEnd: any[];
+
    // Perfect negotiation state: https://www.w3.org/TR/webrtc/#perfect-negotiation-example
    private makingOffer: boolean;
    private ignoreOffer: boolean;

+    // If candidates arrive before we've picked an opponent (which, in particular,
+    // will happen if the opponent sends candidates eagerly before the user answers
+    // the call) we buffer them up here so we can then add the ones from the party we pick
+    private remoteCandidateBuffer = new Map<string, RTCIceCandidate[]>();
+
    constructor(opts: CallOpts) {
        super();
        this.roomId = opts.roomId;
@@ -305,10 +333,11 @@ export class MatrixCall extends EventEmitter {
     * Place a voice call to this room.
     * @throws If you have not specified a listener for 'error' events.
     */
-    placeVoiceCall() {
+    async placeVoiceCall() {
        logger.debug("placeVoiceCall");
        this.checkForErrorListener();
-        this.placeCallWithConstraints(getUserMediaVideoContraints(CallType.Voice));
+        const constraints = getUserMediaContraints(ConstraintsType.Audio);
+        await this.placeCallWithConstraints(constraints);
        this.type = CallType.Voice;
    }

@@ -320,12 +349,13 @@ export class MatrixCall extends EventEmitter {
     * to render the local camera preview.
     * @throws If you have not specified a listener for 'error' events.
     */
-    placeVideoCall(remoteVideoElement: HTMLVideoElement, localVideoElement: HTMLVideoElement) {
+    async placeVideoCall(remoteVideoElement: HTMLVideoElement, localVideoElement: HTMLVideoElement) {
        logger.debug("placeVideoCall");
        this.checkForErrorListener();
        this.localVideoElement = localVideoElement;
        this.remoteVideoElement = remoteVideoElement;
-        this.placeCallWithConstraints(getUserMediaVideoContraints(CallType.Video));
+        const constraints = getUserMediaContraints(ConstraintsType.Video);
+        await this.placeCallWithConstraints(constraints);
        this.type = CallType.Video;
    }

@@ -339,15 +369,31 @@ export class MatrixCall extends EventEmitter {
     * to render the local camera preview.
     * @throws If you have not specified a listener for 'error' events.
     */
-    async placeScreenSharingCall(remoteVideoElement: HTMLVideoElement, localVideoElement: HTMLVideoElement) {
+    async placeScreenSharingCall(
+        remoteVideoElement: HTMLVideoElement,
+        localVideoElement: HTMLVideoElement,
+        selectDesktopCapturerSource: () => Promise<DesktopCapturerSource>,
+    ) {
        logger.debug("placeScreenSharingCall");
        this.checkForErrorListener();
        this.localVideoElement = localVideoElement;
        this.remoteVideoElement = remoteVideoElement;
+
        try {
-            this.screenSharingStream = await navigator.mediaDevices.getDisplayMedia({'audio': false});
+            const screenshareConstraints = await getScreenshareContraints(selectDesktopCapturerSource);
+            if (!screenshareConstraints) return;
+            if (window.electron?.getDesktopCapturerSources) {
+                // We are using Electron
+                logger.debug("Getting screen stream using getUserMedia()...");
+                this.screenSharingStream = await navigator.mediaDevices.getUserMedia(screenshareConstraints);
+            } else {
+                // We are not using Electron
+                logger.debug("Getting screen stream using getDisplayMedia()...");
+                this.screenSharingStream = await navigator.mediaDevices.getDisplayMedia(screenshareConstraints);
+            }
+
            logger.debug("Got screen stream, requesting audio stream...");
-            const audioConstraints = getUserMediaVideoContraints(CallType.Voice);
+            const audioConstraints = getUserMediaContraints(ConstraintsType.Audio);
            this.placeCallWithConstraints(audioConstraints);
        } catch (err) {
            this.emit(CallEvent.Error,
@@ -357,15 +403,14 @@ export class MatrixCall extends EventEmitter {
                ),
            );
        }
-
        this.type = CallType.Video;
    }

-    getOpponentMember() {
+    public getOpponentMember() {
        return this.opponentMember;
    }

-    opponentCanBeTransferred() {
+    public opponentCanBeTransferred() {
        return Boolean(this.opponentCaps && this.opponentCaps["m.call.transferee"]);
    }

@@ -373,7 +418,7 @@ export class MatrixCall extends EventEmitter {
     * Retrieve the local <code>&lt;video&gt;</code> DOM element.
     * @return {Element} The dom element
     */
-    getLocalVideoElement(): HTMLVideoElement {
+    public getLocalVideoElement(): HTMLVideoElement {
        return this.localVideoElement;
    }

@@ -382,7 +427,7 @@ export class MatrixCall extends EventEmitter {
     * used for playing back video capable streams.
     * @return {Element} The dom element
     */
-    getRemoteVideoElement(): HTMLVideoElement {
+    public getRemoteVideoElement(): HTMLVideoElement {
        return this.remoteVideoElement;
    }

@@ -391,7 +436,7 @@ export class MatrixCall extends EventEmitter {
     * used for playing back audio only streams.
     * @return {Element} The dom element
     */
-    getRemoteAudioElement(): HTMLAudioElement {
+    public getRemoteAudioElement(): HTMLAudioElement {
        return this.remoteAudioElement;
    }

@@ -400,7 +445,7 @@ export class MatrixCall extends EventEmitter {
     * video will be rendered to it immediately.
     * @param {Element} element The <code>&lt;video&gt;</code> DOM element.
     */
-    async setLocalVideoElement(element : HTMLVideoElement) {
+    public async setLocalVideoElement(element : HTMLVideoElement) {
        this.localVideoElement = element;

        if (element && this.localAVStream && this.type === CallType.Video) {
@@ -421,7 +466,7 @@ export class MatrixCall extends EventEmitter {
     * the first received video-capable stream will be rendered to it immediately.
     * @param {Element} element The <code>&lt;video&gt;</code> DOM element.
     */
-    setRemoteVideoElement(element : HTMLVideoElement) {
+    public setRemoteVideoElement(element : HTMLVideoElement) {
        if (element === this.remoteVideoElement) return;

        element.autoplay = true;
@@ -443,7 +488,7 @@ export class MatrixCall extends EventEmitter {
     * The audio will *not* be rendered from the remoteVideoElement.
     * @param {Element} element The <code>&lt;video&gt;</code> DOM element.
     */
-    async setRemoteAudioElement(element: HTMLAudioElement) {
+    public async setRemoteAudioElement(element: HTMLAudioElement) {
        if (element === this.remoteAudioElement) return;

        this.remoteAudioElement = element;
@@ -451,16 +496,51 @@ export class MatrixCall extends EventEmitter {
        if (this.remoteStream) this.playRemoteAudio();
    }

+    // The typescript definitions have this type as 'any' :(
+    public async getCurrentCallStats(): Promise<any[]> {
+        if (this.callHasEnded()) {
+            return this.callStatsAtEnd;
+        }
+
+        return this.collectCallStats();
+    }
+
+    private async collectCallStats(): Promise<any[]> {
+        // This happens when the call fails before it starts.
+        // For example when we fail to get capture sources
+        if (!this.peerConn) return;
+
+        const statsReport = await this.peerConn.getStats();
+        const stats = [];
+        for (const item of statsReport) {
+            stats.push(item[1]);
+        }
+
+        return stats;
+    }
+
    /**
     * Configure this call from an invite event. Used by MatrixClient.
     * @param {MatrixEvent} event The m.call.invite event
     */
    async initWithInvite(event: MatrixEvent) {
-        this.msg = event.getContent();
+        const invite = event.getContent();
        this.direction = CallDirection.Inbound;
+
+        // make sure we have valid turn creds. Unless something's gone wrong, it should
+        // poll and keep the credentials valid so this should be instant.
+        const haveTurnCreds = await this.client._checkTurnServers();
+        if (!haveTurnCreds) {
+            logger.warn("Failed to get TURN credentials! Proceeding with call anyway...");
+        }
+
        this.peerConn = this.createPeerConnection();
+        // we must set the party ID before await-ing on anything: the call event
+        // handler will start giving us more call events (eg. candidates) so if
+        // we haven't set the party ID, we'll ignore them.
+        this.chooseOpponent(event);
        try {
-            await this.peerConn.setRemoteDescription(this.msg.offer);
+            await this.peerConn.setRemoteDescription(invite.offer);
        } catch (e) {
            logger.debug("Failed to set remote description", e);
            this.terminate(CallParty.Local, CallErrorCode.SetRemoteDescription, false);
@@ -479,13 +559,6 @@ export class MatrixCall extends EventEmitter {
        this.type = this.remoteStream.getTracks().some(t => t.kind === 'video') ? CallType.Video : CallType.Voice;

        this.setState(CallState.Ringing);
-        this.opponentVersion = this.msg.version;
-        if (this.opponentVersion !== 0) {
-            // ignore party ID in v0 calls: party ID isn't a thing until v1
-            this.opponentPartyId = this.msg.party_id || null;
-        }
-        this.opponentCaps = this.msg.capabilities || {};
-        this.opponentMember = event.sender;

        if (event.getLocalAge()) {
            setTimeout(() => {
@@ -499,7 +572,7 @@ export class MatrixCall extends EventEmitter {
                    }
                    this.emit(CallEvent.Hangup);
                }
-            }, this.msg.lifetime - event.getLocalAge());
+            }, invite.lifetime - event.getLocalAge());
        }
    }

@@ -511,7 +584,6 @@ export class MatrixCall extends EventEmitter {
        // perverse as it may seem, sometimes we want to instantiate a call with a
        // hangup message (because when getting the state of the room on load, events
        // come in reverse order and we want to remember that a call has been hung up)
-        this.msg = event.getContent();
        this.setState(CallState.Ended);
    }

@@ -526,7 +598,11 @@ export class MatrixCall extends EventEmitter {
        logger.debug(`Answering call ${this.callId} of type ${this.type}`);

        if (!this.localAVStream && !this.waitForLocalAVStream) {
-            const constraints = getUserMediaVideoContraints(this.type);
+            const constraints = getUserMediaContraints(
+                this.type == CallType.Video ?
+                    ConstraintsType.Video:
+                    ConstraintsType.Audio,
+            );
            logger.log("Getting user media with constraints", constraints);
            this.setState(CallState.WaitLocalMedia);
            this.waitForLocalAVStream = true;
@@ -709,6 +785,21 @@ export class MatrixCall extends EventEmitter {
        return callOnHold;
    }

+    /**
+     * Sends a DTMF digit to the other party
+     * @param digit The digit (nb. string - '#' and '*' are dtmf too)
+     */
+    sendDtmfDigit(digit: string) {
+        for (const sender of this.peerConn.getSenders()) {
+            if (sender.track.kind === 'audio' && sender.dtmf) {
+                sender.dtmf.insertDTMF(digit);
+                return;
+            }
+        }
+
+        throw new Error("Unable to find a track to send DTMF on");
+    }
+
    private updateMuteStatus() {
        if (!this.localAVStream) {
            return;
@@ -741,8 +832,11 @@ export class MatrixCall extends EventEmitter {
            return;
        }
        if (this.callHasEnded()) {
+            this.stopAllMedia();
            return;
        }
+        this.localAVStream = stream;
+        logger.info("Got local AV stream with id " + this.localAVStream.id);

        this.setState(CallState.CreateOffer);

@@ -768,25 +862,22 @@ export class MatrixCall extends EventEmitter {
            }
        }

-        this.localAVStream = stream;
-        logger.info("Got local AV stream with id " + this.localAVStream.id);
        // why do we enable audio (and only audio) tracks here? -- matthew
        setTracksEnabled(stream.getAudioTracks(), true);
-        this.peerConn = this.createPeerConnection();

        for (const audioTrack of stream.getAudioTracks()) {
            logger.info("Adding audio track with id " + audioTrack.id);
            this.peerConn.addTrack(audioTrack, stream);
        }
        for (const videoTrack of (this.screenSharingStream || stream).getVideoTracks()) {
-            logger.info("Adding audio track with id " + videoTrack.id);
+            logger.info("Adding video track with id " + videoTrack.id);
            this.peerConn.addTrack(videoTrack, stream);
        }

        // Now we wait for the negotiationneeded event
    };

-    private sendAnswer() {
+    private async sendAnswer() {
        const answerContent = {
            answer: {
                sdp: this.peerConn.localDescription.sdp,
@@ -808,12 +899,12 @@ export class MatrixCall extends EventEmitter {
        logger.info(`Discarding ${this.candidateSendQueue.length} candidates that will be sent in answer`);
        this.candidateSendQueue = [];

-        this.sendVoipEvent(EventType.CallAnswer, answerContent).then(() => {
+        try {
+            await this.sendVoipEvent(EventType.CallAnswer, answerContent);
            // If this isn't the first time we've tried to send the answer,
            // we may have candidates queued up, so send them now.
            this.inviteOrAnswerSent = true;
-            this.sendCandidateQueue();
-        }).catch((error) => {
+        } catch (error) {
            // We've failed to answer: back to the ringing state
            this.setState(CallState.Ringing);
            this.client.cancelPendingEvent(error.event);
@@ -826,7 +917,11 @@ export class MatrixCall extends EventEmitter {
            }
            this.emit(CallEvent.Error, new CallError(code, message, error));
            throw error;
-        });
+        }
+
+        // error handler re-throws so this won't happen on error, but
+        // we don't want the same error handling on the candidate queue
+        this.sendCandidateQueue();
    }

    private gotUserMediaForAnswer = async (stream: MediaStream) => {
@@ -930,37 +1025,33 @@ export class MatrixCall extends EventEmitter {
            return;
        }

-        if (!this.partyIdMatches(ev.getContent())) {
-            logger.info(
-                `Ignoring candidates from party ID ${ev.getContent().party_id}: ` +
-                `we have chosen party ID ${this.opponentPartyId}`,
-            );
-            return;
-        }
-
        const cands = ev.getContent().candidates;
        if (!cands) {
            logger.info("Ignoring candidates event with no candidates!");
            return;
        }

-        for (const cand of cands) {
-            if (
-                (cand.sdpMid === null || cand.sdpMid === undefined) &&
-                (cand.sdpMLineIndex === null || cand.sdpMLineIndex === undefined)
-            ) {
-                logger.debug("Ignoring remote ICE candidate with no sdpMid or sdpMLineIndex");
-                return;
-            }
-            logger.debug("Got remote ICE " + cand.sdpMid + " candidate: " + cand.candidate);
-            try {
-                this.peerConn.addIceCandidate(cand);
-            } catch (err) {
-                if (!this.ignoreOffer) {
-                    logger.info("Failed to add remore ICE candidate", err);
-                }
-            }
+        const fromPartyId = ev.getContent().version === 0 ? null : ev.getContent().party_id || null;
+
+        if (this.opponentPartyId === undefined) {
+            // we haven't picked an opponent yet so save the candidates
+            logger.info(`Bufferring ${cands.length} candidates until we pick an opponent`);
+            const bufferedCands = this.remoteCandidateBuffer.get(fromPartyId) || [];
+            bufferedCands.push(...cands);
+            this.remoteCandidateBuffer.set(fromPartyId, bufferedCands);
+            return;
        }
+
+        if (!this.partyIdMatches(ev.getContent())) {
+            logger.info(
+                `Ignoring candidates from party ID ${ev.getContent().party_id}: ` +
+                `we have chosen party ID ${this.opponentPartyId}`,
+            );
+
+            return;
+        }
+
+        this.addIceCandidates(cands);
    }

    /**
@@ -980,12 +1071,7 @@ export class MatrixCall extends EventEmitter {
            return;
        }

-        this.opponentVersion = event.getContent().version;
-        if (this.opponentVersion !== 0) {
-            this.opponentPartyId = event.getContent().party_id || null;
-        }
-        this.opponentCaps = event.getContent().capabilities || {};
-        this.opponentMember = event.sender;
+        this.chooseOpponent(event);

        this.setState(CallState.Connecting);

@@ -1069,8 +1155,21 @@ export class MatrixCall extends EventEmitter {
            await this.peerConn.setRemoteDescription(description);

            if (description.type === 'offer') {
+                // First we sent the direction of the tranciever to what we'd like it to be,
+                // irresepective of whether the other side has us on hold - so just whether we
+                // want the call to be on hold or not. This is necessary because in a few lines,
+                // we'll adjust the direction and unless we do this too, we'll never come off hold.
+                for (const tranceiver of this.peerConn.getTransceivers()) {
+                    tranceiver.direction = this.isRemoteOnHold() ? 'inactive' : 'sendrecv';
+                }
                const localDescription = await this.peerConn.createAnswer();
                await this.peerConn.setLocalDescription(localDescription);
+                // Now we've got our answer, set the direction to the outcome of the negotiation.
+                // We need to do this otherwise Firefox will notice that the direction is not the
+                // currentDirection and try to negotiate itself off hold again.
+                for (const tranceiver of this.peerConn.getTransceivers()) {
+                    tranceiver.direction = tranceiver.currentDirection;
+                }

                this.sendVoipEvent(EventType.CallNegotiate, {
                    description: this.peerConn.localDescription,
@@ -1147,19 +1246,9 @@ export class MatrixCall extends EventEmitter {

        try {
            await this.sendVoipEvent(eventType, content);
-            this.sendCandidateQueue();
-            if (this.state === CallState.CreateOffer) {
-                this.inviteOrAnswerSent = true;
-                this.setState(CallState.InviteSent);
-                this.inviteTimeout = setTimeout(() => {
-                    this.inviteTimeout = null;
-                    if (this.state === CallState.InviteSent) {
-                        this.hangup(CallErrorCode.InviteTimeout, false);
-                    }
-                }, CALL_TIMEOUT_MS);
-            }
        } catch (error) {
-            this.client.cancelPendingEvent(error.event);
+            logger.error("Failed to send invite", error);
+            if (error.event) this.client.cancelPendingEvent(error.event);

            let code = CallErrorCode.SignallingFailed;
            let message = "Signalling failed";
@@ -1174,6 +1263,22 @@ export class MatrixCall extends EventEmitter {

            this.emit(CallEvent.Error, new CallError(code, message, error));
            this.terminate(CallParty.Local, code, false);
+
+            // no need to carry on & send the candidate queue, but we also
+            // don't want to rethrow the error
+            return;
+        }
+
+        this.sendCandidateQueue();
+        if (this.state === CallState.CreateOffer) {
+            this.inviteOrAnswerSent = true;
+            this.setState(CallState.InviteSent);
+            this.inviteTimeout = setTimeout(() => {
+                this.inviteTimeout = null;
+                if (this.state === CallState.InviteSent) {
+                    this.hangup(CallErrorCode.InviteTimeout, false);
+                }
+            }, CALL_TIMEOUT_MS);
        }
    };

@@ -1214,7 +1319,7 @@ export class MatrixCall extends EventEmitter {
            return; // because ICE can still complete as we're ending the call
        }
        logger.debug(
-            "ICE connection state changed to: " + this.peerConn.iceConnectionState,
+            "Call ID " + this.callId + ": ICE connection state changed to: " + this.peerConn.iceConnectionState,
        );
        // ideally we'd consider the call to be connected when we get media but
        // chrome doesn't implement any of the 'onstarted' events yet
@@ -1332,11 +1437,11 @@ export class MatrixCall extends EventEmitter {
    }

    onHangupReceived = (msg) => {
-        logger.debug("Hangup received");
+        logger.debug("Hangup received for call ID " + this.callId);

        // party ID must match (our chosen partner hanging up the call) or be undefined (we haven't chosen
        // a partner yet but we're treating the hangup as a reject as per VoIP v0)
-        if (this.partyIdMatches(msg) || this.opponentPartyId === undefined || this.state === CallState.Ringing) {
+        if (this.partyIdMatches(msg) || this.state === CallState.Ringing) {
            // default reason is user_hangup
            this.terminate(CallParty.Remote, msg.reason || CallErrorCode.UserHangup, true);
        } else {
@@ -1345,7 +1450,7 @@ export class MatrixCall extends EventEmitter {
    };

    onRejectReceived = (msg) => {
-        logger.debug("Reject received");
+        logger.debug("Reject received for call ID " + this.callId);

        // No need to check party_id for reject because if we'd received either
        // an answer or reject, we wouldn't be in state InviteSent
@@ -1367,7 +1472,7 @@ export class MatrixCall extends EventEmitter {
    };

    onAnsweredElsewhere = (msg) => {
-        logger.debug("Answered elsewhere");
+        logger.debug("Call ID " + this.callId + " answered elsewhere");
        this.terminate(CallParty.Remote, CallErrorCode.AnsweredElsewhere, true);
    };

@@ -1440,6 +1545,8 @@ export class MatrixCall extends EventEmitter {
    private async terminate(hangupParty: CallParty, hangupReason: CallErrorCode, shouldEmit: boolean) {
        if (this.callHasEnded()) return;

+        this.callStatsAtEnd = await this.collectCallStats();
+
        if (this.inviteTimeout) {
            clearTimeout(this.inviteTimeout);
            this.inviteTimeout = null;
@@ -1508,7 +1615,7 @@ export class MatrixCall extends EventEmitter {
        }
    }

-    private sendCandidateQueue() {
+    private async sendCandidateQueue() {
        if (this.candidateSendQueue.length === 0) {
            return;
        }
@@ -1520,20 +1627,28 @@ export class MatrixCall extends EventEmitter {
            candidates: cands,
        };
        logger.debug("Attempting to send " + cands.length + " candidates");
-        this.sendVoipEvent(EventType.CallCandidates, content).then(() => {
-            this.candidateSendTries = 0;
-            this.sendCandidateQueue();
-        }, (error) => {
-            for (let i = 0; i < cands.length; i++) {
-                this.candidateSendQueue.push(cands[i]);
-            }
+        try {
+            await this.sendVoipEvent(EventType.CallCandidates, content);
+        } catch (error) {
+            // don't retry this event: we'll send another one later as we might
+            // have more candidates by then.
+            if (error.event) this.client.cancelPendingEvent(error.event);
+
+            // put all the candidates we failed to send back in the queue
+            this.candidateSendQueue.push(...cands);

            if (this.candidateSendTries > 5) {
                logger.debug(
                    "Failed to send candidates on attempt " + this.candidateSendTries +
-                    ". Giving up for now.", error,
+                    ". Giving up on this call.", error,
                );
-                this.candidateSendTries = 0;
+
+                const code = CallErrorCode.SignallingFailed;
+                const message = "Signalling failed";
+
+                this.emit(CallEvent.Error, new CallError(code, message, error));
+                this.hangup(code, false);
+
                return;
            }

@@ -1543,7 +1658,7 @@ export class MatrixCall extends EventEmitter {
            setTimeout(() => {
                this.sendCandidateQueue();
            }, delayMs);
-        });
+        }
    }

    private async placeCallWithConstraints(constraints: MediaStreamConstraints) {
@@ -1553,11 +1668,18 @@ export class MatrixCall extends EventEmitter {
        this.setState(CallState.WaitLocalMedia);
        this.direction = CallDirection.Outbound;
        this.config = constraints;
-        // It would be really nice if we could start gathering candidates at this point
-        // so the ICE agent could be gathering while we open our media devices: we already
-        // know the type of the call and therefore what tracks we want to send.
-        // Perhaps we could do this by making fake tracks now and then using replaceTrack()
-        // once we have the actual tracks? (Can we make fake tracks?)
+
+        // make sure we have valid turn creds. Unless something's gone wrong, it should
+        // poll and keep the credentials valid so this should be instant.
+        const haveTurnCreds = await this.client._checkTurnServers();
+        if (!haveTurnCreds) {
+            logger.warn("Failed to get TURN credentials! Proceeding with call anyway...");
+        }
+
+        // create the peer connection now so it can be gathering candidates while we get user
+        // media (assuming a candidate pool size is configured)
+        this.peerConn = this.createPeerConnection();
+
        try {
            const mediaStream = await navigator.mediaDevices.getUserMedia(constraints);
            this.gotUserMediaForInvite(mediaStream);
@@ -1571,6 +1693,7 @@ export class MatrixCall extends EventEmitter {
        const pc = new window.RTCPeerConnection({
            iceTransportPolicy: this.forceTURN ? 'relay' : undefined,
            iceServers: this.turnServers,
+            iceCandidatePoolSize: this.client._iceCandidatePoolSize,
        });

        // 'connectionstatechange' would be better, but firefox doesn't implement that.
@@ -1586,9 +1709,60 @@ export class MatrixCall extends EventEmitter {

    private partyIdMatches(msg): boolean {
        // They must either match or both be absent (in which case opponentPartyId will be null)
-        const msgPartyId = msg.party_id || null;
+        // Also we ignore party IDs on the invite/offer if the version is 0, so we must do the same
+        // here and use null if the version is 0 (woe betide any opponent sending messages in the
+        // same call with different versions)
+        const msgPartyId = msg.version === 0 ? null : msg.party_id || null;
        return msgPartyId === this.opponentPartyId;
    }
+
+    // Commits to an opponent for the call
+    // ev: An invite or answer event
+    private chooseOpponent(ev: MatrixEvent) {
+        // I choo-choo-choose you
+        const msg = ev.getContent();
+
+        this.opponentVersion = msg.version;
+        if (this.opponentVersion === 0) {
+            // set to null to indicate that we've chosen an opponent, but because
+            // they're v0 they have no party ID (even if they sent one, we're ignoring it)
+            this.opponentPartyId = null;
+        } else {
+            // set to their party ID, or if they're naughty and didn't send one despite
+            // not being v0, set it to null to indicate we picked an opponent with no
+            // party ID
+            this.opponentPartyId = msg.party_id || null;
+        }
+        this.opponentCaps = msg.capabilities || {};
+        this.opponentMember = ev.sender;
+
+        const bufferedCands = this.remoteCandidateBuffer.get(this.opponentPartyId);
+        if (bufferedCands) {
+            logger.info(`Adding ${bufferedCands.length} buffered candidates for opponent ${this.opponentPartyId}`);
+            this.addIceCandidates(bufferedCands);
+        }
+        this.remoteCandidateBuffer = null;
+    }
+
+    private addIceCandidates(cands: RTCIceCandidate[]) {
+        for (const cand of cands) {
+            if (
+                (cand.sdpMid === null || cand.sdpMid === undefined) &&
+                (cand.sdpMLineIndex === null || cand.sdpMLineIndex === undefined)
+            ) {
+                logger.debug("Ignoring remote ICE candidate with no sdpMid or sdpMLineIndex");
+                return;
+            }
+            logger.debug("Got remote ICE " + cand.sdpMid + " candidate: " + cand.candidate);
+            try {
+                this.peerConn.addIceCandidate(cand);
+            } catch (err) {
+                if (!this.ignoreOffer) {
+                    logger.info("Failed to add remore ICE candidate", err);
+                }
+            }
+        }
+    }
 }

 function setTracksEnabled(tracks: Array<MediaStreamTrack>, enabled: boolean) {
@@ -1597,17 +1771,19 @@ function setTracksEnabled(tracks: Array<MediaStreamTrack>, enabled: boolean) {
    }
 }

-function getUserMediaVideoContraints(callType: CallType) {
+function getUserMediaContraints(type: ConstraintsType) {
    const isWebkit = !!navigator.webkitGetUserMedia;

-    switch (callType) {
-        case CallType.Voice:
+    switch (type) {
+        case ConstraintsType.Audio: {
            return {
                audio: {
                    deviceId: audioInput ? {ideal: audioInput} : undefined,
-                }, video: false,
+                },
+                video: false,
            };
-        case CallType.Video:
+        }
+        case ConstraintsType.Video: {
            return {
                audio: {
                    deviceId: audioInput ? {ideal: audioInput} : undefined,
@@ -1622,6 +1798,33 @@ function getUserMediaVideoContraints(callType: CallType) {
                    height: isWebkit ? { exact: 360 } : { ideal: 360 },
                },
            };
+        }
+    }
+}
+
+async function getScreenshareContraints(selectDesktopCapturerSource?: () => Promise<DesktopCapturerSource>) {
+    if (window.electron?.getDesktopCapturerSources && selectDesktopCapturerSource) {
+        // We have access to getDesktopCapturerSources()
+        logger.debug("Electron getDesktopCapturerSources() is available...");
+        const selectedSource = await selectDesktopCapturerSource();
+        if (!selectedSource) return null;
+        return {
+            audio: false,
+            video: {
+                mandatory: {
+                    chromeMediaSource: "desktop",
+                    chromeMediaSourceId: selectedSource.id,
+                },
+            },
+        };
+    } else {
+        // We do not have access to the Electron desktop capturer,
+        // therefore we can assume we are on the web
+        logger.debug("Electron desktopCapturer is not available...");
+        return {
+            audio: false,
+            video: true,
+        };
    }
 }

@@ -138,6 +138,8 @@ export class CallEventHandler {
                );
            }

+            const timeUntilTurnCresExpire = this.client.getTurnServersExpiry() - Date.now();
+            logger.info("Current turn creds expire in " + timeUntilTurnCresExpire + " ms");
            call = createNewMatrixCall(this.client, event.getRoomId(), {
                forceTURN: this.client._forceTURN,
            });