Fixed error thrown when viewing a channel containing an invalid emoji reaction (#7080)

* Added better error handling for when reacting with a non-existant emoji

* Re-added emoji aliases ca, za, and pk

webapp/components/post_view/reaction/index.js

@@ -23,13 +23,18 @@ function makeMapStateToProps() {
             emoji = ownProps.emojis.get(ownProps.emojiName);
         }
 
+        let emojiImageUrl = '';
+        if (emoji) {
+            emojiImageUrl = getEmojiImageUrl(emoji);
+        }
+
         return {
             ...ownProps,
             profiles,
             otherUsersCount: ownProps.reactions.length - profiles.length,
             currentUserId: getCurrentUserId(state),
             reactionCount: ownProps.reactions.length,
-            emojiImageUrl: getEmojiImageUrl(emoji)
+            emojiImageUrl
         };
     };
 }

webapp/components/post_view/reaction/reaction.jsx

@@ -93,6 +93,10 @@ export default class Reaction extends React.PureComponent {
     }
 
     render() {
+        if (!this.props.emojiImageUrl) {
+            return null;
+        }
+
         let currentUserReacted = false;
         const users = [];
         const otherUsersCount = this.props.otherUsersCount;

webapp/make-emojis

@@ -24,6 +24,19 @@ Dir.mkdir emoji_path
 Emoji.create('mattermost')
 FileUtils.cp(File.join(File.dirname(__FILE__), 'images', 'icon64x64.png'), File.join(emoji_path, 'mattermost.png'))
 
+custom_aliases = {
+    "ca" => "canada",
+    "pk" => "pakistan",
+    "za" => "south_africa"
+}
+custom_aliases.each do |custom, original|
+    emoji = Emoji.find_by_alias original
+
+    Emoji.edit_emoji(emoji) do |char|
+      char.add_alias custom
+    end
+end
+
 blacklist = ['basecamp', 'basecampy']
 
 categories = []