FIX: Default to first page when page params is an array.

app/controllers/topics_controller.rb

@@ -49,6 +49,10 @@ class TopicsController < ApplicationController
     # existing installs.
     return wordpress if params[:best].present?
 
+    # work around people somehow sending in arrays,
+    # arrays are not supported
+    params[:page] = params[:page].to_i rescue 1
+
     opts = params.slice(:username_filters, :filter, :page, :post_number, :show_deleted)
     username_filters = opts[:username_filters]
 
@@ -65,7 +69,7 @@ class TopicsController < ApplicationController
       raise Discourse::NotFound
     end
 
-    page = params[:page].to_i
+    page = params[:page]
     if (page < 0) || ((page - 1) * @topic_view.chunk_size > @topic_view.topic.highest_post_number)
       raise Discourse::NotFound
     end
@@ -529,7 +533,7 @@ class TopicsController < ApplicationController
     url << "/#{post_number}" if post_number.to_i > 0
     url << ".json" if request.format.json?
 
-    page = params[:page].to_i
+    page = params[:page]
     url << "?page=#{page}" if page != 0
 
     redirect_to url, status: 301

lib/topic_view.rb

@@ -43,10 +43,7 @@ class TopicView
       self.instance_variable_set("@#{key}".to_sym, value)
     end
 
-    # work around people somehow sending in arrays,
-    # arrays are not supported
-    @page = @page.to_i rescue 1
-    @page = 1 if @page.zero?
+    @page = 1 if (!@page || @page.zero?)
     @chunk_size = options[:slow_platform] ? TopicView.slow_chunk_size : TopicView.chunk_size
     @limit ||= @chunk_size
 
@@ -183,7 +180,7 @@ class TopicView
     return filter_posts_by_ids(opts[:post_ids]) if opts[:post_ids].present?
     return filter_best(opts[:best], opts) if opts[:best].present?
 
-    filter_posts_paged(opts[:page].to_i)
+    filter_posts_paged(@page)
   end
 
   def primary_group_names

spec/controllers/topics_controller_spec.rb

@@ -563,6 +563,11 @@ describe TopicsController do
       expect(response).to redirect_to(topic.relative_url + "/42?page=123")
     end
 
+    it 'does not accept page params as an array' do
+      xhr :get, :show, id: topic.slug, post_number: 42, page: [2]
+      expect(response).to redirect_to("#{topic.relative_url}/42?page=1")
+    end
+
     it 'returns 404 when an invalid slug is given and no id' do
       xhr :get, :show, id: 'nope-nope'
       expect(response.status).to eq(404)