From 02780faa6c2cbea1b1bc6011c9ed86b692d0eb4a Mon Sep 17 00:00:00 2001
From: CJ <38697367+imisshtml@users.noreply.github.com>
Date: Thu, 12 Dec 2019 19:25:00 -0500
Subject: [PATCH] MM-18054 Fix Comment Line showing (#3696)

* MM-18054 Fix Comment Line showing

Restructured the check for the previous post to make sure comment line does not appear for posts on same thread, but from different users.

* MM-18054 Updated after review

Updated the logic to be more bulletproof
---
 app/components/post/index.js                    |  6 ++++--
 app/components/post/post.js                     |  2 --
 .../__snapshots__/post_header.test.js.snap      | 17 +++++++++++++++++
 app/components/post_header/post_header.js       |  5 ++---
 4 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/app/components/post/index.js b/app/components/post/index.js
index ae76dd5b6..ef208d651 100644
--- a/app/components/post/index.js
+++ b/app/components/post/index.js
@@ -10,6 +10,7 @@ import {isChannelReadOnlyById} from 'mattermost-redux/selectors/entities/channel
 import {getPost, makeGetCommentCountForPost, makeIsPostCommentMention} from 'mattermost-redux/selectors/entities/posts';
 import {getUser, getCurrentUserId} from 'mattermost-redux/selectors/entities/users';
 import {getMyPreferences, getTheme} from 'mattermost-redux/selectors/entities/preferences';
+import {isStartOfNewMessages} from 'mattermost-redux/utils/post_list';
 import {isPostFlagged, isSystemMessage} from 'mattermost-redux/utils/post_utils';
 
 import {insertToDraft, setPostTooltipVisible} from 'app/actions/views/channel';
@@ -40,7 +41,8 @@ function makeMapStateToProps() {
     const isPostCommentMention = makeIsPostCommentMention();
     return function mapStateToProps(state, ownProps) {
         const post = ownProps.post || getPost(state, ownProps.postId);
-        const previousPost = getPost(state, ownProps.previousPostId);
+        const previousPostId = isStartOfNewMessages(ownProps.previousPostId) ? ownProps.beforePrevPostId : ownProps.previousPostId;
+        const previousPost = getPost(state, previousPostId);
         const beforePrevPost = getPost(state, ownProps.beforePrevPostId);
 
         const myPreferences = getMyPreferences(state);
@@ -52,7 +54,7 @@ function makeMapStateToProps() {
         let commentedOnPost = null;
 
         if (ownProps.renderReplies && post && post.root_id) {
-            if (ownProps.previousPostId) {
+            if (previousPostId) {
                 if (previousPost && (previousPost.id === post.root_id || previousPost.root_id === post.root_id)) {
                     // Previous post is root post or previous post is in same thread
                     isFirstReply = false;
diff --git a/app/components/post/post.js b/app/components/post/post.js
index d008271aa..1afd68ce4 100644
--- a/app/components/post/post.js
+++ b/app/components/post/post.js
@@ -254,7 +254,6 @@ export default class Post extends PureComponent {
             isLandscape,
             previousPostExists,
             beforePrevPostUserId,
-            isFirstReply,
         } = this.props;
 
         if (!post) {
@@ -306,7 +305,6 @@ export default class Post extends PureComponent {
                     theme={theme}
                     previousPostExists={previousPostExists}
                     beforePrevPostUserId={beforePrevPostUserId}
-                    isFirstReply={isFirstReply}
                 />
             );
         }
diff --git a/app/components/post_header/__snapshots__/post_header.test.js.snap b/app/components/post_header/__snapshots__/post_header.test.js.snap
index 1fc62210e..715f2c956 100644
--- a/app/components/post_header/__snapshots__/post_header.test.js.snap
+++ b/app/components/post_header/__snapshots__/post_header.test.js.snap
@@ -383,6 +383,23 @@ exports[`PostHeader should match snapshot when post is same thread, so dont disp
       />
     </View>
   </View>
+  <FormattedText
+    defaultMessage="Commented on {name}{apostrophe} message: "
+    id="post_body.commentedOn"
+    style={
+      Object {
+        "color": "rgba(61,60,64,0.65)",
+        "lineHeight": 21,
+        "marginBottom": 3,
+      }
+    }
+    values={
+      Object {
+        "apostrophe": "'s",
+        "name": "John Doe",
+      }
+    }
+  />
 </React.Fragment>
 `;
 
diff --git a/app/components/post_header/post_header.js b/app/components/post_header/post_header.js
index 7ee9d4708..4dfda604b 100644
--- a/app/components/post_header/post_header.js
+++ b/app/components/post_header/post_header.js
@@ -46,7 +46,6 @@ export default class PostHeader extends PureComponent {
         previousPostExists: PropTypes.bool,
         post: PropTypes.object,
         beforePrevPostUserId: PropTypes.string,
-        isFirstReply: PropTypes.bool,
         isLandscape: PropTypes.bool.isRequired,
     };
 
@@ -70,9 +69,9 @@ export default class PostHeader extends PureComponent {
             previousPostExists,
             renderReplies,
             theme,
-            isFirstReply,
         } = this.props;
-        if (!isFirstReply || !renderReplies || !commentedOnDisplayName || (!previousPostExists && post.user_id === beforePrevPostUserId)) {
+
+        if (!renderReplies || !commentedOnDisplayName || (!previousPostExists && post.user_id === beforePrevPostUserId)) {
             return null;
         }