fix JS error and incorrect comment thread for SHIFT+UP (#6574)

3 files changed, 15 insertions, 10 deletions

diff --git a/webapp/components/common/comment_icon.jsx b/webapp/components/common/comment_icon.jsx
index 63218971f..4505d51bc 100644
--- a/webapp/components/common/comment_icon.jsx
+++ b/webapp/components/common/comment_icon.jsx
@@ -21,7 +21,7 @@ export default function CommentIcon(props) {
         iconStyle = iconStyle + ' ' + props.searchStyle;
     }
 
-    let commentIconId = props.idPrefix;
+    let commentIconId = props.channelId + props.idPrefix;
     if (props.idCount > -1) {
         commentIconId += props.idCount;
     }
@@ -47,11 +47,13 @@ CommentIcon.propTypes = {
     idCount: PropTypes.number,
     handleCommentClick: PropTypes.func.isRequired,
     searchStyle: PropTypes.string,
-    commentCount: PropTypes.number
+    commentCount: PropTypes.number,
+    channelId: PropTypes.string
 };
 
 CommentIcon.defaultProps = {
     idCount: -1,
     searchStyle: '',
-    commentCount: 0
+    commentCount: 0,
+    channelId: ''
 };
\ No newline at end of file
diff --git a/webapp/components/create_post.jsx b/webapp/components/create_post.jsx
index 74104cf2a..2735718e1 100644
--- a/webapp/components/create_post.jsx
+++ b/webapp/components/create_post.jsx
@@ -504,11 +504,12 @@ export default class CreatePost extends React.Component {
             return;
         }
 
+        const lastPostEl = document.getElementById(this.state.channelId + 'commentIcon0');
+
         if (!e.ctrlKey && !e.metaKey && !e.altKey && !e.shiftKey && e.keyCode === KeyCodes.UP && this.state.message === '') {
             e.preventDefault();
 
-            const channelId = ChannelStore.getCurrentId();
-            const lastPost = PostStore.getCurrentUsersLatestPost(channelId);
+            const lastPost = PostStore.getCurrentUsersLatestPost(this.state.channelId);
             if (!lastPost) {
                 return;
             }
@@ -529,15 +530,15 @@ export default class CreatePost extends React.Component {
                 channelId: lastPost.channel_id,
                 comments: PostStore.getCommentCount(lastPost)
             });
-        } else if (!e.ctrlKey && !e.metaKey && !e.altKey && e.shiftKey && e.keyCode === KeyCodes.UP && this.state.message === '') {
+        } else if (!e.ctrlKey && !e.metaKey && !e.altKey && e.shiftKey && e.keyCode === KeyCodes.UP && this.state.message === '' && lastPostEl) {
             e.preventDefault();
             if (document.createEvent) {
-                var evt = document.createEvent('MouseEvents');
+                const evt = document.createEvent('MouseEvents');
                 evt.initMouseEvent('click', true, true, window, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
-                document.getElementById('commentIcon0').dispatchEvent(evt);
+                lastPostEl.dispatchEvent(evt);
             } else if (document.createEventObject) {
-                var evObj = document.createEventObject();
-                document.getElementById('commentIcon0').fireEvent('onclick', evObj);
+                const evObj = document.createEventObject();
+                lastPostEl.fireEvent('onclick', evObj);
             }
         }
 
diff --git a/webapp/components/post_view/components/post_info.jsx b/webapp/components/post_view/components/post_info.jsx
index 74ce32817..39a0b1fec 100644
--- a/webapp/components/post_view/components/post_info.jsx
+++ b/webapp/components/post_view/components/post_info.jsx
@@ -17,6 +17,7 @@ import Constants from 'utils/constants.jsx';
 import DelayedAction from 'utils/delayed_action.jsx';
 import {Overlay} from 'react-bootstrap';
 import EmojiPicker from 'components/emoji_picker/emoji_picker.jsx';
+import ChannelStore from 'stores/channel_store.jsx';
 
 import PropTypes from 'prop-types';
 
@@ -351,6 +352,7 @@ export default class PostInfo extends React.Component {
                     idCount={idCount}
                     handleCommentClick={this.props.handleCommentClick}
                     commentCount={this.props.commentCount}
+                    channelId={ChannelStore.getCurrentId()}
                 />
             );