3 files changed, 12 insertions, 9 deletions
diff --git a/web/react/utils/constants.jsx b/web/react/utils/constants.jsx
index 24af9998b..99bd2453c 100644
--- a/web/react/utils/constants.jsx
+++ b/web/react/utils/constants.jsx
@@ -138,6 +138,7 @@ export default {
     ],
     MONTHS: ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'],
     MAX_DMS: 20,
+    MAX_CHANNEL_POPOVER_COUNT: 20,
     DM_CHANNEL: 'D',
     OPEN_CHANNEL: 'O',
     PRIVATE_CHANNEL: 'P',
diff --git a/web/react/utils/text_formatting.jsx b/web/react/utils/text_formatting.jsx
index 3a912fd75..f0bd46f9d 100644
--- a/web/react/utils/text_formatting.jsx
+++ b/web/react/utils/text_formatting.jsx
@@ -188,7 +188,7 @@ function highlightCurrentMentions(text, tokens) {
             const newAlias = `MM_SELFMENTION${index}`;
 
             newTokens.set(newAlias, {
-                value: `<span class='mention-highlight'>${alias}</span>` + token.extraText,
+                value: `<span class='mention-highlight'>${alias}</span>` + (token.extraText || ''),
                 originalText: token.originalText
             });
             output = output.replace(alias, newAlias);
diff --git a/web/react/utils/utils.jsx b/web/react/utils/utils.jsx
index 80c377d7f..aa9146183 100644
--- a/web/react/utils/utils.jsx
+++ b/web/react/utils/utils.jsx
@@ -854,7 +854,7 @@ export function isMobile() {
 
 export function isComment(post) {
     if ('root_id' in post) {
-        return post.root_id !== '';
+        return post.root_id !== '' && post.root_id != null;
     }
     return false;
 }
@@ -981,13 +981,15 @@ export function displayUsername(userId) {
     const nameFormat = PreferenceStore.getPreference(Constants.Preferences.CATEGORY_DISPLAY_SETTINGS, 'name_format', {value: 'false'}).value;
 
     let username = '';
-    if (nameFormat === 'nickname_full_name') {
-        username = user.nickname || getFullName(user);
-    } else if (nameFormat === 'full_name') {
-        username = getFullName(user);
-    }
-    if (!username.trim().length) {
-        username = user.username;
+    if (user) {
+        if (nameFormat === 'nickname_full_name') {
+            username = user.nickname || getFullName(user);
+        } else if (nameFormat === 'full_name') {
+            username = getFullName(user);
+        }
+        if (!username.trim().length) {
+            username = user.username;
+        }
     }
 
     return username;