MM-53506 Fixed duplicated command response in thread/channel (#23969) (#30310)

- Ephemeral system answers from commands in threads are also posted in parent channel
- Removed an obsolete condition that provoked the bug

webapp/channels/src/packages/mattermost-redux/src/reducers/entities/posts.test.ts

@@ -722,6 +722,23 @@ describe('postsInChannel', () => {
             });
         });
 
+        it('should do nothing when a reply-post comes and CRT is ON, even if ephemeral', () => {
+            const state = deepFreeze({
+                channel1: [],
+            });
+
+            const nextState = reducers.postsInChannel(state, {
+                type: PostTypes.RECEIVED_NEW_POST,
+                data: {id: 'post1', channel_id: 'channel1', root_id: 'parent1', type: 'system_ephemeral'},
+                features: {crtEnabled: true},
+            }, {}, {});
+
+            expect(nextState).toBe(state);
+            expect(nextState).toEqual({
+                channel1: [],
+            });
+        });
+
         it('should reset when called for (e.g. when CRT is TOGGLED)', () => {
             const state = deepFreeze({
                 channel1: [],

webapp/channels/src/packages/mattermost-redux/src/reducers/entities/posts.ts

@@ -22,7 +22,6 @@ import type {
 import type {MMReduxAction} from 'mattermost-redux/action_types';
 import {ChannelTypes, PostTypes, UserTypes, ThreadTypes, CloudTypes} from 'mattermost-redux/action_types';
 import {Posts} from 'mattermost-redux/constants';
-import {PostTypes as PostConstant} from 'mattermost-redux/constants/posts';
 import {comparePosts, isPermalink, shouldUpdatePost} from 'mattermost-redux/utils/post_utils';
 
 export function removeUnneededMetadata(post: Post) {
@@ -472,7 +471,7 @@ export function postsInChannel(state: Record<string, PostOrderBlock[]> = {}, act
     case PostTypes.RECEIVED_NEW_POST: {
         const post = action.data as Post;
 
-        if (action.features?.crtEnabled && post.root_id && post.type !== PostConstant.EPHEMERAL) {
+        if (action.features?.crtEnabled && post.root_id) {
             return state;
         }