FIX: convert emoji to unicode in topic titles in emails

app/mailers/user_notifications.rb

@@ -4,6 +4,7 @@ require_dependency 'age_words'
 
 class UserNotifications < ActionMailer::Base
   include UserNotificationsHelper
+  include ApplicationHelper
   helper :application
   default charset: 'UTF-8'
 
@@ -117,7 +118,7 @@ class UserNotifications < ActionMailer::Base
             .for_mailing_list(user, min_date)
             .where('posts.post_type = ?', Post.types[:regular])
             .where('posts.deleted_at IS NULL AND posts.hidden = false AND posts.user_deleted = false')
-            .where("posts.post_number > ? AND posts.score > ?", 1, ScoreCalculator.default_score_weights[:like_score] * 5.0)
+            .where("posts.post_number > ? AND posts.score > ?", 1, ScoreCalculator.default_score_weights[:like_score] * 1.0)
             .limit(SiteSetting.digest_posts)
       else
         []
@@ -399,7 +400,7 @@ class UserNotifications < ActionMailer::Base
         invite_template = "user_notifications.invited_to_topic_body"
       end
       topic_excerpt = post.excerpt.tr("\n", " ") if post.is_first_post? && post.excerpt
-      message = I18n.t(invite_template, username: username, topic_title: title, topic_excerpt: topic_excerpt, site_title: SiteSetting.title, site_description: SiteSetting.site_description)
+      message = I18n.t(invite_template, username: username, topic_title: gsub_emoji_to_unicode(title), topic_excerpt: topic_excerpt, site_title: SiteSetting.title, site_description: SiteSetting.site_description)
 
       unless translation_override_exists
         html = UserNotificationRenderer.new(Rails.configuration.paths["app/views"]).render(
@@ -434,7 +435,7 @@ class UserNotifications < ActionMailer::Base
     end
 
     email_opts = {
-      topic_title: title,
+      topic_title: gsub_emoji_to_unicode(title),
       topic_title_url_encoded: title ? URI.encode(title) : title,
       message: message,
       url: post.url,

app/views/user_notifications/digest.html.erb

@@ -124,7 +124,7 @@ body, table, td, th, h1, h2, h3 {font-family: Helvetica, Arial, sans-serif !impo
       <td style="padding: 0 8px 8px 16px; text-align:left; width:100%;">
         <h2 style="font-size:18px;font-weight:400;line-height:1.3;margin:0;padding:0;word-wrap:normal">
           <a href="<%= Discourse.base_url_no_prefix + t.relative_url %>" style="font-weight:400;line-height:1.3;margin:0;padding:0;text-decoration:none">
-            <strong><%= t.title.truncate(60, separator: /\s/) -%></strong>
+            <strong><%= gsub_emoji_to_unicode(t.title.truncate(60, separator: /\s/)) -%></strong>
           </a>
         </h2>
         <%- if SiteSetting.show_topic_featured_link_in_digest && t.featured_link %>
@@ -279,7 +279,7 @@ body, table, td, th, h1, h2, h3 {font-family: Helvetica, Arial, sans-serif !impo
       </td>
       <td style="color:#0a0a0a;line-height:1.3;padding:0 8px 8px 8px;text-align:right;">
         <p style="color:#8f8f8f;line-height:1.3;margin:0 0 10px 0;padding:0;text-align:right;">
-          <a href="<%= post.full_url -%>" style="font-weight:400;line-height:1.3;margin:0;padding:0;text-align:left;text-decoration:none"><%= post.topic.title.truncate(60, separator: /\s/) -%></a>
+          <a href="<%= post.full_url -%>" style="font-weight:400;line-height:1.3;margin:0;padding:0;text-align:left;text-decoration:none"><%= gsub_emoji_to_unicode(post.topic.title.truncate(60, separator: /\s/)) -%></a>
         </p>
         <a href="<%= post.full_url -%>" class="with-accent-colors" style="width:100%;text-decoration:none;padding:8px 16px;white-space: nowrap;">
           <%=t 'user_notifications.digest.join_the_discussion' %>
@@ -325,7 +325,7 @@ body, table, td, th, h1, h2, h3 {font-family: Helvetica, Arial, sans-serif !impo
     <tr style="vertical-align:top;">
       <td style="padding:8px;text-align:left;">
         <a href="<%= Discourse.base_url_no_prefix + t.relative_url %>" style="font-weight:400;line-height:1.3;margin:0;padding:0;text-decoration:none">
-          <strong><%= t.title.truncate(60, separator: /\s/) -%></strong>
+          <strong><%= gsub_emoji_to_unicode(t.title.truncate(60, separator: /\s/)) -%></strong>
         </a>
         <%- if SiteSetting.show_topic_featured_link_in_digest && t.featured_link %>
           <a class='topic-featured-link' href='<%= t.featured_link %>'><%= raw topic_featured_link_domain(t.featured_link) %></a>