Store more information and add proper display of rollbacks

app/controllers/post_history_controller.rb

@@ -28,21 +28,24 @@ def rollback
       comment: "Rollback of [##{index}: #{@history.post_history_type.name}](#{post_history_url(@post, anchor: index)})"
     }
 
-    # Do the actual rollback
-    unless rollback_post_history
-      flash[:danger] = "Unable to rollback revision: #{@post.errors.full_messages.join(', ')}"
-      redirect_to post_history_path(@post)
-      return
-    end
+    # Do the actual rollback within a transaction with the history to ensure we don't end up in inconsistent states
+    PostHistory.transaction do
+      unless rollback_post_history
+        flash[:danger] = "Unable to rollback revision: #{@post.errors.full_messages.join(', ')}"
+        redirect_to post_history_path(@post)
+        return
+      end
 
-    opts.merge(after: @post.body_markdown, after_title: @post.title, after_tags: @post.tags.to_a)
+      opts.merge(after: @post.body_markdown, after_title: @post.title, after_tags: @post.tags.to_a)
 
-    # Record in the history that this element was rolled back
-    new_history = PostHistory.history_rolled_back(@post, current_user, **opts)
+      # Record in the history that this element was rolled back
+      new_history = PostHistory.history_rolled_back(@post, current_user, **opts)
 
-    # Store that the previous history was rolled back
-    # TODO Add migration
-    # @history.update(rolled_back_with: new_history)
+      # Set the original to be rolled back
+      @history.extra = {} unless @history.extra
+      @history.extra[:rolled_back_with] = new_history.id
+      @history.save!
+    end
 
     flash[:success] = 'History successfully rolled back'
     redirect_to post_history_path(@post)
@@ -64,9 +67,9 @@ def rollback_post_history
                    last_activity: DateTime.now, last_activity_by: current_user)
     when 'question_reopened'
       predecessor = find_predecessor('question_closed')
-      # TODO We need to find the close reason properly, this doesn't exist
       @post.update(closed: true, closed_by: predecessor.user, closed_at: predecessor.created_at,
-                   close_reason: predecessor.close_reason, duplicate_post: nil,
+                   close_reason_id: predecessor.extra&.fetch('close_reason_id', nil),
+                   duplicate_post_id: predecessor.extra&.fetch('duplicate_post_id', nil),
                    last_activity: DateTime.now, last_activity_by: current_user)
     when 'post_edited'
       @post.title = @history.before_title if @history.before_title && @history.before_title != @history.after_title

app/controllers/posts_controller.rb

@@ -279,7 +279,9 @@ def close
 
     if @post.update(closed: true, closed_by: current_user, closed_at: DateTime.now, last_activity: DateTime.now,
                     last_activity_by: current_user, close_reason: reason, duplicate_post: duplicate_of)
-      PostHistory.question_closed(@post, current_user, comment: comment)
+      PostHistory.question_closed(@post, current_user, comment: comment, extra: {
+                                    close_reason_id: reason.id, duplicate_post_id: duplicate_of&.id
+                                  })
       render json: { status: 'success' }
     else
       render json: { status: 'failed', message: helpers.i18ns('posts.cant_close_post'),

app/models/post_history.rb

@@ -39,6 +39,11 @@ def tags_added
     after_tags - before_tags
   end
 
+  # @return [Boolean] whether this history item was rolled back
+  def rolled_back?
+    extra.present? && !!extra.fetch('rolled_back_with', nil)
+  end
+
   def self.method_missing(name, *args, **opts)
     unless args.length >= 2
       raise NoMethodError

app/views/post_history/post.html.erb

@@ -7,7 +7,13 @@
 <% @history.each.with_index do |event, index| %>
   <details class="history-event" id="<%= @history.size - index %>">
     <summary>
-      <strong>#<%= @history.size - index %>: <%= event.post_history_type.name.humanize %></strong>
+      <strong>
+        <% if event.rolled_back? %>
+          <del>#<%= @history.size - index %>: <%= event.post_history_type.name.humanize %></del>
+        <% else %>
+          #<%= @history.size - index %>: <%= event.post_history_type.name.humanize %>
+        <% end %>
+      </strong>
       <span class="has-color-tertiary-600 history-meta">
         <span>
           by