Fetch joinedAtVersion before change log fetch for new groups

ts/groups.ts

@@ -2946,11 +2946,6 @@ async function getGroupUpdates({
         group,
         serverPublicParamsBase64,
         newRevision,
-
-        // If we just linked and this is a group where we have been a member
-        // from the beggining - applying all changes since the start is the best
-        // case scenario.
-        fallbackRevision: 0,
       });
 
       return result;
@@ -2973,36 +2968,6 @@ async function getGroupUpdates({
         throw error;
       }
     }
-
-    // Fetch of logs starting from the revision 0 failed, so we probably were
-    // just invited to the group. Try fetching logs from the same revision as in
-    // this message.
-    if (isFirstFetch) {
-      try {
-        const result = await updateGroupViaLogs({
-          group,
-          serverPublicParamsBase64,
-          newRevision,
-          fallbackRevision: newRevision,
-        });
-
-        return result;
-      } catch (error) {
-        if (error.code === TEMPORAL_AUTH_REJECTED_CODE) {
-          // We will fail over to the updateGroupViaState call below
-          log.info(
-            `getGroupUpdates/${logId}: Temporal credential failure, now fetching full state`
-          );
-        } else if (error.code === GROUP_ACCESS_DENIED_CODE) {
-          // We will fail over to the updateGroupViaState call below
-          log.info(
-            `getGroupUpdates/${logId}: Log access denied, now fetching full state`
-          );
-        } else {
-          throw error;
-        }
-      }
-    }
   }
 
   if (window.GV2_ENABLE_STATE_PROCESSING) {
@@ -3120,11 +3085,9 @@ async function updateGroupViaSingleChange({
 async function updateGroupViaLogs({
   group,
   serverPublicParamsBase64,
-  fallbackRevision,
   newRevision,
 }: {
   group: ConversationAttributesType;
-  fallbackRevision: number;
   newRevision: number;
   serverPublicParamsBase64: string;
 }): Promise<UpdatesResultType> {
@@ -3137,7 +3100,6 @@ async function updateGroupViaLogs({
   const groupCredentials = getCredentialsForToday(data);
   const deltaOptions = {
     group,
-    fallbackRevision,
     newRevision,
     serverPublicParamsBase64,
     authCredentialBase64: groupCredentials.today.credential,
@@ -3261,13 +3223,11 @@ function getGroupCredentials({
 async function getGroupDelta({
   group,
   newRevision,
-  fallbackRevision,
   serverPublicParamsBase64,
   authCredentialBase64,
 }: {
   group: ConversationAttributesType;
   newRevision: number;
-  fallbackRevision: number;
   serverPublicParamsBase64: string;
   authCredentialBase64: string;
 }): Promise<UpdatesResultType> {
@@ -3292,7 +3252,7 @@ async function getGroupDelta({
   const currentRevision = group.revision;
   let revisionToFetch = isNumber(currentRevision)
     ? currentRevision + 1
-    : fallbackRevision;
+    : undefined;
 
   let response;
   const changes: Array<Proto.IGroupChanges> = [];

ts/textsecure/SendMessage.ts

@@ -2134,7 +2134,7 @@ export default class MessageSender {
   }
 
   async getGroupLog(
-    startVersion: number,
+    startVersion: number | undefined,
     options: Readonly<GroupCredentialsType>
   ): Promise<GroupLogResponseType> {
     return this.server.getGroupLog(startVersion, options);

ts/textsecure/WebAPI.ts

@@ -538,6 +538,7 @@ const URL_CALLS = {
   getIceServers: 'v1/accounts/turn',
   getStickerPackUpload: 'v1/sticker/pack/form',
   groupLog: 'v1/groups/logs',
+  groupJoinedAtVersion: 'v1/groups/joined_at_version',
   groups: 'v1/groups',
   groupsViaLink: 'v1/groups/join',
   groupToken: 'v1/groups/token',
@@ -803,7 +804,7 @@ export type WebAPIType = {
     options: GroupCredentialsType
   ) => Promise<Proto.GroupExternalCredential>;
   getGroupLog: (
-    startVersion: number,
+    startVersion: number | undefined,
     options: GroupCredentialsType
   ) => Promise<GroupLogResponseType>;
   getIceServers: () => Promise<GetIceServersResultType>;
@@ -2590,7 +2591,7 @@ export function initialize({
     }
 
     async function getGroupLog(
-      startVersion: number,
+      startVersion: number | undefined,
       options: GroupCredentialsType
     ): Promise<GroupLogResponseType> {
       const basicAuth = generateGroupAuth(
@@ -2598,6 +2599,22 @@ export function initialize({
         options.authCredentialPresentationHex
       );
 
+      // If we don't know starting revision - fetch it from the server
+      if (startVersion === undefined) {
+        const { data: joinedData } = await _ajax({
+          basicAuth,
+          call: 'groupJoinedAtVersion',
+          contentType: 'application/x-protobuf',
+          host: storageUrl,
+          httpType: 'GET',
+          responseType: 'byteswithdetails',
+        });
+
+        const { joinedAtVersion } = Proto.Member.decode(joinedData);
+
+        return getGroupLog(joinedAtVersion, options);
+      }
+
       const withDetails = await _ajax({
         basicAuth,
         call: 'groupLog',