Fix management of selectedMessage in redux

ts/components/conversation/Timeline.stories.tsx

@@ -359,7 +359,6 @@ const actions = () => ({
   ),
   setIsNearBottom: action('setIsNearBottom'),
   learnMoreAboutDeliveryIssue: action('learnMoreAboutDeliveryIssue'),
-  loadAndScroll: action('loadAndScroll'),
   loadOlderMessages: action('loadOlderMessages'),
   loadNewerMessages: action('loadNewerMessages'),
   loadNewestMessages: action('loadNewestMessages'),

ts/components/conversation/Timeline.tsx

@@ -161,7 +161,6 @@ export type PropsActionsType = {
   ) => void;
 
   learnMoreAboutDeliveryIssue: () => unknown;
-  loadAndScroll: (messageId: string) => unknown;
   loadOlderMessages: (messageId: string) => unknown;
   loadNewerMessages: (messageId: string) => unknown;
   loadNewestMessages: (messageId: string, setFocus?: boolean) => unknown;
@@ -220,7 +219,6 @@ const getActions = createSelector(
       'reviewGroupMemberNameCollision',
       'reviewMessageRequestNameCollision',
       'learnMoreAboutDeliveryIssue',
-      'loadAndScroll',
       'loadOlderMessages',
       'loadNewerMessages',
       'loadNewestMessages',

ts/models/conversations.ts

@@ -1370,10 +1370,6 @@ export class ConversationModel extends window.Backbone
     this.debouncedUpdateLastMessage!();
   }
 
-  addIncomingMessage(message: MessageModel): void {
-    this.addSingleMessage(message);
-  }
-
   // New messages might arrive while we're in the middle of a bulk fetch from the
   //   database. We'll wait until that is done before moving forward.
   async addSingleMessage(

ts/state/ducks/conversations.ts

@@ -1726,6 +1726,14 @@ function messagesReset({
   scrollToMessageId,
   unboundedFetch,
 }: MessageResetOptionsType): MessagesResetActionType {
+  for (const message of messages) {
+    strictAssert(
+      message.conversationId === conversationId,
+      `messagesReset(${conversationId}): invalid message conversationId ` +
+        `${message.conversationId}`
+    );
+  }
+
   return {
     type: 'MESSAGES_RESET',
     payload: {
@@ -2625,8 +2633,12 @@ export function reducer(
 
     return {
       ...state,
+      ...(state.selectedConversationId === conversationId
+        ? {
             selectedMessage: scrollToMessageId,
             selectedMessageCounter: state.selectedMessageCounter + 1,
+          }
+        : {}),
       messagesLookup: {
         ...messagesLookup,
         ...lookup,
@@ -3035,12 +3047,9 @@ export function reducer(
     const nextState = {
       ...omit(state, 'contactSpoofingReview'),
       selectedConversationId: id,
+      selectedMessage: messageId,
     };
 
-    if (messageId) {
-      nextState.selectedMessage = messageId;
-    }
-
     if (switchToAssociatedView && id) {
       const conversation = getOwn(state.conversationLookup, id);
       if (!conversation) {

ts/state/smart/Timeline.tsx

@@ -71,7 +71,6 @@ export type TimelinePropsType = ExternalProps &
     | 'downloadNewVersion'
     | 'kickOffAttachmentDownload'
     | 'learnMoreAboutDeliveryIssue'
-    | 'loadAndScroll'
     | 'loadNewerMessages'
     | 'loadNewestMessages'
     | 'loadOlderMessages'

ts/views/conversation_view.tsx

@@ -509,7 +509,6 @@ export class ConversationView extends window.Backbone.View<ConversationModel> {
       learnMoreAboutDeliveryIssue,
       loadNewerMessages: this.model.loadNewerMessages.bind(this.model),
       loadNewestMessages: this.model.loadNewestMessages.bind(this.model),
-      loadAndScroll: this.model.loadAndScroll.bind(this.model),
       loadOlderMessages: this.model.loadOlderMessages.bind(this.model),
       markMessageRead,
       onBlock: createMessageRequestResponseHandler(