From 1f9fab9a0c1ef6c0530f148108bce3372818a1d9 Mon Sep 17 00:00:00 2001
From: Travis Ralston <travisr@matrix.org>
Date: Wed, 11 Aug 2021 15:11:13 -0600
Subject: [PATCH 1/2] Fix conditional on returning file tree spaces

If a tree space was deleted then it'll still hold a Room object for us, which is not much help if we're effectively trying to get the joined trees.
---
 spec/unit/matrix-client.spec.js | 23 +++++++++++++++++++++++
 src/client.ts                   |  2 +-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/spec/unit/matrix-client.spec.js b/spec/unit/matrix-client.spec.js
index 090ffeed14d..755abfb10ee 100644
--- a/spec/unit/matrix-client.spec.js
+++ b/spec/unit/matrix-client.spec.js
@@ -270,6 +270,29 @@ describe("MatrixClient", function() {
         expect(tree.room).toBe(mockRoom);
     });
 
+    it("should not get (unstable) file trees if not joined", async () => {
+        const roomId = "!room:example.org";
+        const mockRoom = {
+            getMyMembership: () => "leave", // "not join"
+        };
+        client.getRoom = (getRoomId) => {
+            expect(getRoomId).toEqual(roomId);
+            return mockRoom;
+        };
+        const tree = client.unstableGetFileTreeSpace(roomId);
+        expect(tree).toBeFalsy();
+    });
+
+    it("should not get (unstable) file trees for unknown rooms", async () => {
+        const roomId = "!room:example.org";
+        client.getRoom = (getRoomId) => {
+            expect(getRoomId).toEqual(roomId);
+            return null; // imply unknown
+        };
+        const tree = client.unstableGetFileTreeSpace(roomId);
+        expect(tree).toBeFalsy();
+    });
+
     it("should not get (unstable) file trees with invalid create contents", async () => {
         const roomId = "!room:example.org";
         const mockRoom = {
diff --git a/src/client.ts b/src/client.ts
index 2bcda09e44e..83b484c44e6 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -8060,7 +8060,7 @@ export class MatrixClient extends EventEmitter {
      */
     public unstableGetFileTreeSpace(roomId: string): MSC3089TreeSpace {
         const room = this.getRoom(roomId);
-        if (!room) return null;
+        if (room?.getMyMembership() !== 'join') return null;
 
         const createEvent = room.currentState.getStateEvents(EventType.RoomCreate, "");
         const purposeEvent = room.currentState.getStateEvents(

From 4e2ee3b3a817d457d35ca9f487f574a066c679cc Mon Sep 17 00:00:00 2001
From: Travis Ralston <travisr@matrix.org>
Date: Wed, 11 Aug 2021 15:18:24 -0600
Subject: [PATCH 2/2] It helps to fix the other tests too

---
 spec/unit/matrix-client.spec.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/spec/unit/matrix-client.spec.js b/spec/unit/matrix-client.spec.js
index 755abfb10ee..82e166f67e1 100644
--- a/spec/unit/matrix-client.spec.js
+++ b/spec/unit/matrix-client.spec.js
@@ -237,6 +237,7 @@ describe("MatrixClient", function() {
     it("should get (unstable) file trees with valid state", async () => {
         const roomId = "!room:example.org";
         const mockRoom = {
+            getMyMembership: () => "join",
             currentState: {
                 getStateEvents: (eventType, stateKey) => {
                     if (eventType === EventType.RoomCreate) {
@@ -296,6 +297,7 @@ describe("MatrixClient", function() {
     it("should not get (unstable) file trees with invalid create contents", async () => {
         const roomId = "!room:example.org";
         const mockRoom = {
+            getMyMembership: () => "join",
             currentState: {
                 getStateEvents: (eventType, stateKey) => {
                     if (eventType === EventType.RoomCreate) {
@@ -330,6 +332,7 @@ describe("MatrixClient", function() {
     it("should not get (unstable) file trees with invalid purpose/subtype contents", async () => {
         const roomId = "!room:example.org";
         const mockRoom = {
+            getMyMembership: () => "join",
             currentState: {
                 getStateEvents: (eventType, stateKey) => {
                     if (eventType === EventType.RoomCreate) {