/artists/show_or_new: make public; add "artist doesn't exist" page.

* Fix access denied error when anonymous users open /artists/show_or_new.

* When the artist doesn't exist, take user to "artist doesn't exist"
  page instead of redirecting to /artists/new.

app/controllers/artists_controller.rb

@@ -1,6 +1,6 @@
 class ArtistsController < ApplicationController
   respond_to :html, :xml, :json
-  before_filter :member_only, :except => [:index, :show, :banned]
+  before_filter :member_only, :except => [:index, :show, :show_or_new, :banned]
   before_filter :builder_only, :only => [:destroy]
   before_filter :admin_only, :only => [:ban, :unban]
   before_filter :load_artist, :only => [:ban, :unban, :show, :edit, :update, :destroy, :undelete]
@@ -96,7 +96,9 @@ class ArtistsController < ApplicationController
     if @artist
       redirect_to artist_path(@artist)
     else
-      redirect_to new_artist_path(:name => params[:name])
+      @artist = Artist.new(name: params[:name])
+      @post_set = PostSets::Artist.new(@artist)
+      respond_with(@artist)
     end
   end
 

app/views/artists/show_or_new.html.erb

@@ -0,0 +1,5 @@
+<%= render layout: "show" do %>
+  <div>
+    <p>This artist entry does not exist. <%= link_to "Create new artist entry", new_artist_path(name: params[:name]) %>.</p>
+  </div>
+<% end %>

test/functional/artists_controller_test.rb

@@ -42,7 +42,7 @@ class ArtistsControllerTest < ActionController::TestCase
       assert_redirected_to(@masao)
 
       get :show_or_new, { name: "nobody" }, { user_id: @user.id }
-      assert_redirected_to(new_artist_path(name: "nobody"))
+      assert_response :success
     end
 
     should "get the edit page" do