From ffe636e6bdaff7fd7ab60402bde5ddaf5a51ec95 Mon Sep 17 00:00:00 2001
From: mmd <mmd-osm@users.noreply.github.com>
Date: Thu, 12 Dec 2019 10:40:01 +0100
Subject: [PATCH 1/2] Add In-Reply-To, References headers to email

Closes https://github.com/openstreetmap/openstreetmap-website/issues/2430
---
 app/mailers/notifier.rb | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/app/mailers/notifier.rb b/app/mailers/notifier.rb
index b125999810..676ae6f3b5 100644
--- a/app/mailers/notifier.rb
+++ b/app/mailers/notifier.rb
@@ -94,11 +94,14 @@ def diary_comment_notification(comment, recipient)
       @readurl = diary_entry_url(comment.diary_entry.user, comment.diary_entry, :anchor => "comment#{comment.id}")
       @commenturl = diary_entry_url(comment.diary_entry.user, comment.diary_entry, :anchor => "newcomment")
       @replyurl = new_message_url(comment.user, :message => { :title => "Re: #{comment.diary_entry.title}" })
-
+      @ref = "osm-diary-#{comment.diary_entry.id}@#{Settings.server_url}"
       @author = @from_user
 
       attach_user_avatar(comment.user)
 
+      headers["In-Reply-To"] = @ref
+      headers["References"]  = @ref
+
       mail :from => from_address(comment.user.display_name, "c", comment.id, comment.digest, recipient.id),
            :to => recipient.email,
            :subject => I18n.t("notifier.diary_comment_notification.subject", :user => comment.user.display_name)
@@ -126,6 +129,7 @@ def note_comment_notification(comment, recipient)
       @comment = comment.body
       @owner = recipient == comment.note.author
       @event = comment.event
+      @ref = "osm-note-#{comment.note.id}@#{Settings.server_url}"
 
       @commenter = if comment.author
                      comment.author.display_name
@@ -136,6 +140,9 @@ def note_comment_notification(comment, recipient)
       @author = @commenter
       attach_user_avatar(comment.author)
 
+      headers["In-Reply-To"] = @ref
+      headers["References"]  = @ref
+
       subject = if @owner
                   I18n.t("notifier.note_comment_notification.#{@event}.subject_own", :commenter => @commenter)
                 else
@@ -157,6 +164,7 @@ def changeset_comment_notification(comment, recipient)
       @time = comment.created_at
       @changeset_author = comment.changeset.user.display_name
       @author = @commenter
+      @ref = "osm-changeset-#{comment.changeset.id}@#{Settings.server_url}"
 
       subject = if @owner
                   I18n.t("notifier.changeset_comment_notification.commented.subject_own", :commenter => @commenter)
@@ -166,6 +174,9 @@ def changeset_comment_notification(comment, recipient)
 
       attach_user_avatar(comment.author)
 
+      headers["In-Reply-To"] = @ref
+      headers["References"]  = @ref
+
       mail :to => recipient.email, :subject => subject
     end
   end

From 480eaa1b3638f29fcf05b67f67e31319f596130b Mon Sep 17 00:00:00 2001
From: mmd-osm <mmd.osm@gmail.com>
Date: Mon, 30 Dec 2019 23:04:15 +0100
Subject: [PATCH 2/2] Added helper function set_references for mail header

---
 app/mailers/notifier.rb | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/app/mailers/notifier.rb b/app/mailers/notifier.rb
index 676ae6f3b5..1d33db9d8b 100644
--- a/app/mailers/notifier.rb
+++ b/app/mailers/notifier.rb
@@ -94,13 +94,11 @@ def diary_comment_notification(comment, recipient)
       @readurl = diary_entry_url(comment.diary_entry.user, comment.diary_entry, :anchor => "comment#{comment.id}")
       @commenturl = diary_entry_url(comment.diary_entry.user, comment.diary_entry, :anchor => "newcomment")
       @replyurl = new_message_url(comment.user, :message => { :title => "Re: #{comment.diary_entry.title}" })
-      @ref = "osm-diary-#{comment.diary_entry.id}@#{Settings.server_url}"
       @author = @from_user
 
       attach_user_avatar(comment.user)
 
-      headers["In-Reply-To"] = @ref
-      headers["References"]  = @ref
+      set_references("diary", comment.diary_entry)
 
       mail :from => from_address(comment.user.display_name, "c", comment.id, comment.digest, recipient.id),
            :to => recipient.email,
@@ -129,7 +127,6 @@ def note_comment_notification(comment, recipient)
       @comment = comment.body
       @owner = recipient == comment.note.author
       @event = comment.event
-      @ref = "osm-note-#{comment.note.id}@#{Settings.server_url}"
 
       @commenter = if comment.author
                      comment.author.display_name
@@ -140,8 +137,7 @@ def note_comment_notification(comment, recipient)
       @author = @commenter
       attach_user_avatar(comment.author)
 
-      headers["In-Reply-To"] = @ref
-      headers["References"]  = @ref
+      set_references("note", comment.note)
 
       subject = if @owner
                   I18n.t("notifier.note_comment_notification.#{@event}.subject_own", :commenter => @commenter)
@@ -164,7 +160,6 @@ def changeset_comment_notification(comment, recipient)
       @time = comment.created_at
       @changeset_author = comment.changeset.user.display_name
       @author = @commenter
-      @ref = "osm-changeset-#{comment.changeset.id}@#{Settings.server_url}"
 
       subject = if @owner
                   I18n.t("notifier.changeset_comment_notification.commented.subject_own", :commenter => @commenter)
@@ -174,8 +169,7 @@ def changeset_comment_notification(comment, recipient)
 
       attach_user_avatar(comment.author)
 
-      headers["In-Reply-To"] = @ref
-      headers["References"]  = @ref
+      set_references("changeset", comment.changeset)
 
       mail :to => recipient.email, :subject => subject
     end
@@ -221,4 +215,10 @@ def from_address(name, type, id, digest, user_id = nil)
       Settings.email_from
     end
   end
+
+  def set_references(scope, reference_object)
+    ref = "osm-#{scope}-#{reference_object.id}@#{Settings.server_url}"
+    headers["In-Reply-To"] = ref
+    headers["References"]  = ref
+  end
 end